From Radio-phobia to Radio-euphoria: Low Radiation Doses: Safe, Useful, and Necessary (Springer Praxis Books) 3031426444, 9783031426445

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ILYA OBODOVSKIY

From Radio-phobia to Radio-euphoria LOW RADIATION DOSES: SAFE, USEFUL, AND NECESSARY

Springer Praxis Books

Popular Science

The Springer Praxis Popular Science series contains fascinating stories from around the world and across many different disciplines. The titles in this series are written with the educated lay reader in mind, approaching nitty-gritty science in an engaging, yet digestible way. Authored by active scholars, researchers, and industry professionals, the books herein offer far-ranging and unique perspectives, exploring realms as distant as Antarctica or as abstract as consciousness itself, as modern as the Information Age or as old our planet Earth. The books are illustrative in their approach and feature essential mathematics only where necessary. They are a perfect read for those with a curious mind who wish to expand their understanding of the vast world of science.

Ilya Obodovskiy

From Radio-phobia to Radio-euphoria Low Radiation Doses: Safe, Useful, and Necessary

Ilya Obodovskiy San Diego, CA, USA

Springer Praxis Books ISSN 2626-6113     ISSN 2626-6121 (electronic) Popular Science ISBN 978-3-031-42644-5    ISBN 978-3-031-42645-2 (eBook) https://doi.org/10.1007/978-3-031-42645-2 © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2023 This work is subject to copyright. All rights are solely and exclusively licensed by the Publisher, whether the whole or part of the material is concerned, specifically the rights of reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors, and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, expressed or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. This Springer imprint is published by the registered company Springer Nature Switzerland AG The registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland Paper in this product is recyclable.

Preface

I conceived and partly wrote this book in a relatively peaceful time. But while I was working, war broke out in Europe. A war unleashed by a nuclear state whose politicians and propagandists constantly threaten to use nuclear weapons or destroy the reactors of Ukrainian nuclear power plants. In both cases, radioactive contamination of vast territories and a sharp increase in the radiation background worldwide are possible. Before this war, interest in radiation and its effects on health may have been a mere curiosity. But in the conditions of possible nuclear explosions, this issue is moving into the area of as close attention as the weather forecast. Most of the world’s population rightly believes that large doses of ionizing radiation are dangerous. Unfortunately, these concerns apply to any, including small, doses. This condition is called radiophobia. Using a vast amount of research, I will explain to the readers of this book that small doses are safe, beneficial, and at some level even necessary. There is nothing unusual in the statement about the usefulness of small doses with the danger of large ones. The book contains a large number of various examples confirming this idea. We will point out one here: a temperature of 20 °C (68 °F) is comfortable, and, for example, 100 °C (212 °F) is a burn. In degrees of temperature, all people understand from school age when to wear a thin shirt and when a sheepskin coat. The book will help readers navigate a new sphere in radiation doses and imagine the border between dangerous and safe values. It will allow one to avoid dangerous zones, if necessary—to take appropriate measures and not to be afraid of zones, although with an increased background, but safe. San Diego, CA

Ilya Obodovskiy v

About Mathematics, Formulas, Numbers, Graphs, and Terminology

One of the greatest scientists of the end of the XIX century, William Thomson, better known in the world as Lord Kelvin, it was in his honor that the unit of absolute temperature was named, wrote: “If you can measure and express what you are talking about in numbers, you know something about it, but if you can’t, your knowledge is poor and unsatisfactory.” The ability to calculate allows you to move from accumulating knowledge to acquiring skills, from “know-what” to “know-how.” However, it is clear that the abundant use of mathematics will make the book difficult to understand for a wide range of readers. Another major physicist of our time, Stephen Hawking, in the preface to his book “A Brief History of Time” about mathematics in a popular book, said: “I was told that each formula included in the book would halve the number of buyers.” Hawking managed with just one formula. There will be no formulas at all in this book. And yet, mathematics is indispensable. There are no formulas, but mathematics breaks through in the form of numbers and graphs. In the scientific papers on which the author wrote this book, doses are given in sieverts, grays, roentgens, rads, rems, or other units used at different times. The author tried, wherever possible, to transfer the doses to the same system. But this is not always possible, for such a translation there may not be enough information. In addition, it must be understood that effective and equivalent doses, expressed in sieverts, apply only to the human body and for stochastic effects, i.e., mainly for radiation carcinogenesis. Units of measurement of source activity and doses, which are unfamiliar to the general public, are actually easy to understand. This is no more difficult than comparing prices for different goods, for example, in dollars and euros. Moreover, the ratio of the dollar and the euro can change daily, and the ratio, vii

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About Mathematics, Formulas, Numbers, Graphs, and Terminology

for example, of roentgen and gray, is established unambiguously once and for all. One of the objectives of the book is to help interested readers in this matter. A summary of the units of measure and their ratios is given in the Appendix. To facilitate a comparison of the numerical values given in the book for activity, dose, and dose rate, lists of typical and official values are given in the last tables in the Appendix. Another slightly less obvious manifestation of the influence of mathematics is the presentation of measurement results in the form of graphs. We hope that this moment will not cause serious difficulties. Currently, many media provide information on price dynamics, exchange rates, election results, etc., in the form of graphs. It is known that scientists speak their own language, often obscure to the general public. Technical terminology and jargon also penetrate into non-­ fiction books, making them hard to read. In the 1930s, the future Nobel laureate physicist Max Delbrück became interested in genetics. At first, listening to speeches or stories of geneticists, he was perplexed: “Why did they need to invent a special gibberish language so that their criminal intentions are not clear to others” (quoted from the book by M.D. Frank-Kamenetskii “Unraveling DNA: The Most Important Molecule of Life”). The peculiarity of genetics was demonstrated by the famous phrase: “A recessive allele affects the phenotype only if the genotype is homozygous.” But really this phrase accurately conveys the meaning, and it is perhaps difficult to say otherwise. In our opinion, the majority of readers prefer to obtain a more or less clear and, if possible, simple picture of the complex phenomena being described. It is clear that such an approach leads to certain losses. On the other hand, simplifying complex phenomena is an extremely fruitful way of solving complex problems. We illustrate this statement with two examples. The movement of electrons, i.e. electric current in matter is an extremely complex process. Electrons pass through potential barriers and potential wells, collide with inhomogeneities of the crystal lattice and impurity atoms, change the direction of movement, give, and receive energy, etc. However, it turns out that all this complexity can be forgotten if you enter a single parameter— resistance. For this simplification, the name of the author who formulated the corresponding law, Georg Ohm, was honored to become the name of the unit of electrical resistance. In the 1930s, a young man, Pavel Cherenkov, discovered a new, previously unknown glow, now in all languages, called Cherenkov radiation. Cherenkov observed this glow in various complex substances, solutions, and mixtures. Neither he nor his scientific supervisor, academician Sergei Vavilov could understand the origin of this glow. The famous Soviet scientists Igor Tamm

  About Mathematics, Formulas, Numbers, Graphs, and Terminology 

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and Ilya Frank explained this phenomenon by replacing all the complexities of substances with a single parameter—the refractive index. For this simplification, they were awarded (together with Cherenkov) the Nobel Prize. The so-called Central Dogma of Molecular Biology, simplifying the real picture, also played a positive role in biology. Recently, prominent American experts Douglas Hanahan and Robert Weinberg wrote in an article in the journal Cell: “We foresee cancer research developing into a logical science, where the complexities of the disease, described in the laboratory and clinic, will become understandable in terms of a small number of underlying principles.” As you can see, biologists also strive for simplifications. So, reader, in this book, you will get a simplified picture of the complex processes of the effects of ionizing radiation on health. The reader will find in the book a list of popular books that will expand and deepen the understanding of the problem.

Introduction

There is no doubt that at present, a significant part of the population, at least in civilized countries, suffers from radio-phobia. Although, the verb “suffers” in this case should be used with caution. I remember an anecdote. Doctor: “So, patient, you are suffering from alcoholism.” Patient: “No, doctor, what are you? I don’t suffer from it, I enjoy it.” It is unlikely that anyone enjoys radio-phobia, but people, without a doubt, have a certain craving for the mysteriously frightening. This craving appeared, most likely, in ancient times, and even Homer, indulging the tastes of the ancient Greek public, composed the horrors that Odysseus encountered in his wanderings. Closer to our time, the so-called Gothic novel appeared, relishing the pleasant feeling of nightmares, and then the “black novel” with elements of the supernatural and mysterious. Crowds of ghosts, vampires, monsters, and aliens from the other world wandered through literary works and later the stage and movies. The famous German storyteller Ernst Theodor Amadeus Hoffmann and the great American writer Edgar Allan Poe paid tribute to the mysteriously frightening theme. Mary Shelley’s Frankenstein or the Modern Prometheus and Bram Stoker’s Dracula were milestones in following the painful needs of the population. In Russia, N.V. Gogol, for example, was noted on this path with the story “Viy.” Nowadays, readers are reading horror novels by Stephen King. A deafening impression was once made on the public by Edvard Munch’s painting “The Scream” (Fig. 1a). The artist used the frightening impression of this painting in a modification of the radiation hazard sign (Fig. 1c), which enhances its intimidating effect. It is generally accepted that in fact we love disasters. Don’t feed us with bread—let us fight some huge threat, whether it is global inequality, global xi

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Fig. 1  (a) One of the variants of the most famous work of E. Munch “The Scream,” (b) a standard sign of radiation hazard, (c) a sign of radiation hazard, stylized as a painting by Munch. Figure from The Scream, Wikipedia—https://en.wikipedia.org/wiki/The_ Scream. Public domain

warming, a pandemic, world terrorism, the onset of an era of lack of spirituality, fascism raising its head, the collapse of the great Western civilization, etc. Today, we have an apocalypse for every taste and color. So, people feel the need for horror stories. And nuclear radiation is perfect for this purpose. Invisible and inaudible, without color, smell, and taste, they already arouse concern with their mysteriousness alone. The invisible enemy is the most terrible; terrible properties are unwittingly attributed to him, which in fact may not exist. If there were no nuclear radiation, they would have to be invented, on purpose, as the most potent tool for tickling nerves. It is interesting to note that the emergence of household electricity was also met with caution. Fear was caused by numerous cases of instant electric shock, leaving no traces. Confirmation of the dangerous nature of electricity was the emergence of a new type of execution in the electric chair. The first murderer was executed in this way in 1890. One of the frightening properties of electricity, as well as radiation, was its invisibility. There were wires here, but it wasn’t easy to imagine what moved along them. Electricity caused fears soon

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after its appearance, but then people got used to it; as we see with radiation, the opposite is true. Invisible radio waves caused fears and continue to cause them. The possible impact of mobile phone radiation on the ears and brain is being seriously studied in many laboratories worldwide; many ordinary people suspect the harmfulness of products from microwave ovens. This variant of radio-phobia has not yet reached its point in the list of phobias, but, as they say, it is not over yet. Since the emergence of life on Earth, i.e., almost 4 billion years, all life has been immersed in an ocean of ionizing radiation. For the first 3.5 billion years, living organisms lived in water, where radiation doses are noticeably lower than on land. And only then did life get out onto land and, having apparently found the larger doses it needed, reached its amazing diversity and perfection. Homo sapiens, which arose from evolution about 200 thousand years ago, although he is considered a reasonable person, did not know about the existence of radiation penetrating him for a long time. Radiation was discovered in a historical perspective quite recently. At the end of 1895, the German scientist V.K. Roentgen discovered a new, previously unknown, radiation. A little later, in the spring of 1896, the French scientist A. Becquerel discovered the radioactive radiation of atoms. And humankind has discovered that in nature, there is well-penetrating radiation. All the time of acquaintance of people with radiation can be clearly divided into two periods. The first period, the period of delight and fascination with new phenomena, was called the period of radio-euphoria and X-ray mania. This period continued until about the middle of the twentieth century. And then, the population’s mood changed quite dramatically, and fears and horrors replaced the enthusiasm. The period of radio-phobia has come. I want to remind you that in Greek, “phobia” simply means fear. But in modern use, this concept has a specific semantic connotation. A phobia is not just fear but unreasonable, unjustified fear. As a suffix attached to other words, it means various types of phobias. Specialists currently count a vast number of different phobias—many hundreds. In the lists of phobias, you can find well-­ known ones, for example, claustrophobia; there are also quite exotic ones, for example, “Paraskavedekatriaphobia”—the fear of Friday the 13th. However, this phobia seemed eccentric only out of ignorance. A closer examination of the subject showed that, according to Wikipedia, in today’s society with a developed economy, the problem of Friday the 13th has turned from mystical into quite tangible economic. People who are more or less prone to “paraskavedekatriaphobia” try to reduce their activity as much as

xiv Introduction

possible on such days, which, according to some estimates, in the US economy alone leads to a loss of 800–900 million dollars each day. (In 2023, Friday the 13th will be two times, in January and October, in 2024—in September and December, in 2025—only in June and in 2026—only in February). You can imagine what problems radio-phobia creates for people and what losses are in the economy. Radio-phobia is one of a long list of several hundred different phobias. One of this book’s objectives is to help get rid of it or at least weaken its influence. In this book, the author will try to popularly explain in what cases, under what conditions, radiation is scary, and in which, on the contrary, it is safe and even useful, whether there is reason to consider radio-phobia as a really unreasonable fear. So, is nuclear radiation dangerous? Yes, large doses are dangerous; the out-­ of-­control radiation that creates them is hazardous. Radiation is dangerous, as wild animals are dangerous in the wild and even in a zoo if they break out of their cages, as dangerous as playing with matches at a gas station, as dangerous as drunk bus drivers or inept airliner pilots. But if appropriate safety measures are taken and observed, the danger of exposure to large doses is very unlikely. Whether people can comply with these measures is a question that the author will try to discuss in this book, but to which he does not have a definitive answer. But if a meeting with large doses of radiation is very unlikely for the vast majority of readers, then all of us, without exception, regardless of gender, age, place of residence, specialty, type of occupation, financial situation, etc. are continuously exposed to low doses. Large doses of radiation are a formidable and dangerous animal, and small ones are affectionate and gentle. In this book, in chapters 7-10, we will discuss in detail the three main features of the effects on the body of small doses: • safety, • usefulness, • necessity. The boundary between dangerous and safe doses and the certainty of this boundary will also be discussed there. It is well known that radiation is not only inherently useful in small doses but also harmful or even dangerous in large doses. Overeating is harmful, sugar, salt and many other components of our diet are harmful in large quantities. It is clear that, within reasonable limits, these components are

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absolutely necessary. The book contains many similar analogies and explanations that illustrate this seemingly paradoxical fact. However, as we know, an analogy is not proof. To substantiate the fact of the safety of small doses with the obvious danger of large doses and with the obvious primary damaging effect of nuclear radiation, no analogies and reasoning are required, but experimental or observational data. And it is on such data that the author relies in this book. Radio-phobia arose after the Second World War. The sight of the devastated Japanese cities of Hiroshima and Nagasaki as a result of the nuclear bombing aroused fear in the world of the colossal destructive power of atomic energy. This fear was automatically transferred to the product of the implementation of atomic energy—to radiation. However, in fact, the role of radiation in the death of people both at the time of the explosions and for a long time after them turned out to be insignificant, much weaker than is often written about. This statement will be substantiated in more detail in Chap. 7. Apparently, the main event that led to the spread of the fear of radiation, radio-phobia around the globe was the episode with the Japanese tuna Fukuryu-Maru, which fell under radioactive fallout after the thermonuclear explosion “Bravo” on Bikini Atoll on March 1, 1954. The veil of secrecy collapsed; the whole world learned about the dangers posed precisely by radiation and was frightened. Accidents at nuclear installations served as another breeding ground for radio-phobia. There were quite a few minor accidents, but their consequences were minimal. The strongest fuel for radio-phobia was the result of accidents that can safely be called disasters, first at the weapons-grade plutonium production complex in Windscale, UK in 1957, then at the Three Mile Island nuclear power plants in the USA in 1979, at Chernobyl in the former USSR in 1986 and in Fukushima, Japan in 2011. So, the danger of thermonuclear conflicts and catastrophes at nuclear facilities forms the basis of the negative background that feeds radio-phobia. With all the further content of the book, the author will try to show that radio-phobia is indeed an unjustified fear. Nevertheless, I want to make a paradoxical assumption here. There may be a fear of ionizing radiation, although it is not justified, but it previously played some positive role. During the Cold War, when there was a very significant danger of a thermonuclear conflict and subsequent extensive contamination of the globe with radioactive substances, radio-phobia of the population could be a deterrent. It is difficult to say to what extent radio-phobic sentiments influenced the decisions of the leaders of the opposing countries, but perhaps they somehow influenced, and perhaps these sentiments extended to themselves and their

xvi Introduction

families. They are people too. Anyway, despite the fundamental ideological differences, the leaders of the USSR and the USA managed to move away, or rather crawl away, from the edge of the abyss. During humankind’s acquaintance with radiation, the danger of the military use of atomic weapons arose, disappeared, and again matured. There may continue to be periods of weakening and growth of tension in relations between world powers, but it is important that nuclear weapons, figuratively speaking, hang on the wall, and there is always a danger that in the next act of the world play this gun hanging over the world will fire and this act may be the last for human civilization. So, it would seem that there is something to be afraid of. In addition to military applications, possible accidents at nuclear installations also pose a danger. And even if Japan, a technologically highly developed country, failed to foresee measures that now seem quite obvious, turned out to be helpless in the face of the challenge of the elements, then it would seem, what can we say about other, less advanced countries. The cautious attitude of people to any sources of radiation was associated, in particular, with the expectation of possible nuclear terrorism. Any action by the authorities had to take into account the danger of panic. Therefore, the question arises whether it is proper, when such dangers exist, to call for an exit from the stage of pathological radio-phobia. Is it ethical in principle to start the fight against radio-phobia? There is another reason to doubt the ethics of this struggle. Many thousands of people who took part in the liquidation of the consequences of the nuclear disasters in Chernobyl and Fukushima, evacuated from their homes, sick, suffering, and losing their loved ones, people who believe that they performed a feat and received significant doses of radiation, real or imaginary, categorically disagree with scientific assessments, are offended and outraged when they talk about the safety or even usefulness of radiation. We are witnessing a profound difference between the real facts and the ideas of the affected people and public opinion about the real role of radiation in people’s lives. The population’s fears, especially of the liquidators and evacuees, are understandable. Indeed, everyone knows that large doses are dangerous; this circumstance is not in doubt. Affected people are usually incredulous, but perhaps they can believe that small doses are safe. But the vast majority of the population does not know where the border between dangerous and safe doses is, how clear it is, and how to determine it. These questions are discussed in this book.

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But already here, it is useful to note that the greatest harm to the victims of the accidents in Chernobyl and Fukushima was brought not by the radiation itself, but by the psychological aspects of the accident and the post-accident situation, a significant change in living conditions. Forced evacuation, restrictions in the usual activities, conflicting information about the possible consequences of the accident, and a radical change in the way of life of these people led to psychological discomfort and significantly affected their health, regardless of the effect of radiation. The atmosphere of secrecy, silence, and outright deceit had an extremely bad effect on the mood of the people. After reviewing the secret materials of the meetings of the Politburo of the Central Committee of the CPSU, the highest authority in the USSR, the well-known Ukrainian politician and journalist Alla Yaroshinskaya, characterizes her attitude to the events in Chernobyl, or rather, to the actions of the authorities with the following words: “The main lethal isotope that flew out of the Chernobyl reactor was not cesium-137, but deception-86.” So, is it ethical to raise the issue of combating radio-phobia? Understanding humankind’s need for horror stories, is it worth it, it would seem from noble motives, to deprive readers of one of the phobias? Isn’t it as shameful as depriving a child of his favorite toy? The answer seems pretty clear to me. First, there are enough nightmares without radio-phobia. “Nuclear winter,” “Ozone hole,” “Global warming,” “Reversal of the Earth’s poles,” the regularly expected “Doomsday,” pandemics, epidemics, Ebola, bird flu, and many other things. The closest example is the coronavirus. But most importantly, radio-phobia is very expensive for humanity. After Chernobyl, up to 200,000 pregnant women in Europe had an abortion, fearing the occurrence of congenital deformities in future children. Measurements carried out in many countries over the past years have shown that the additional dose due to the Chernobyl fallout of radioactive substances turned out to be extremely insignificant, it could not affect the health of the fetus. But hundreds of thousands of desired children were not born due to radio-phobia. It is known that tens of thousands of women refuse regular mammography, fearing these studies cause breast cancer. Note that the fear of radiation is stronger than the fear of missing out on the early stages of cancer when a cure is likely. Well, radio-phobia also leads to a restriction and sometimes to a complete cessation of the use of nuclear energy. Some countries of Western Europe, such as Sweden, Germany, Spain, Belgium, and Holland, under pressure from a frightened population, legally abandoned their plans. Following the

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Fukushima accident due to the Greens’ anti-nuclear activity on May 30, 2011, Germany formally announced its plans to phase out nuclear power over the next 11 years completely. Eight nuclear power plants were shut down immediately, and it was promised that the remaining ones would be turned off in the near future. On December 31, 2021, Berlin closed three of the six remaining nuclear power plants in the country. The remaining three are scheduled to close by the end of the next year. Before the Fukushima accident, Germany produced about a quarter of its electricity from nuclear fuel. According to political scientists, a sharp rejection of nuclear energy could play a fatal role in the German economy. It is unlikely that the so-called renewable sources can compensate for such a sharp loss of generating capacity. In October 2022, the Chancellor decided that Germany’s three remaining nuclear power reactors would keep operating until mid-April 2023 to offset the reduced gas supply from Russia. In mid-April, they really were stopped. Adopted on the wave of radio-phobia, excessively strict radiation safety standards significantly complicate the use of radiation technologies and reduce their economic efficiency. Radio-phobia is harmful to health. Like many other phobias, radio-phobia is a pathological fear with an inadequate response. It is also called obsessive fear. Experts point out that phobias can provoke little pleasant symptoms: heart palpitations, increased sweating, weakness, fainting, nausea, and even a feeling of suffocation. Radio-phobia certainly complicates life, especially for people with high emotional sensitivity. Any phobia is stress, upset nerves, a bad mood, and radio-phobia is no exception. And finally, the validity of the fight against radio-phobia is confirmed by the fact that the safety of small doses of radiation corresponds to objective reality. The possibility of influencing the mood of the population on the decisions of the authorities is doubtful, I don’t see any other benefit from radio-­ phobia, and the damage caused by radio-phobia is absolutely real and, as we have seen, very significant. That is why the author believes it would be good for readers to understand the real situation with nuclear radiation on planet Earth, and it is better to do without radio-phobia. The safety of low doses of radiation is an objective reality. Therefore, there is no need to be afraid of what you cannot be afraid of, but what you really need to be afraid of is fear itself.

Contents

1 The  World in the Era of Great Discoveries: X-rays and Radioactivity����������������������������������������������������������������������������������  1 2 X  -ray Mania���������������������������������������������������������������������������������� 11 2.1 Wilhelm Conrad Röntgen���������������������������������������������������� 11 2.2 Cathode Rays���������������������������������������������������������������������� 11 2.3 Röntgen Experiments, History of Discovery������������������������ 16 2.4 The Reaction of the Press and Society���������������������������������� 21 2.5 Something Else About Röntgen ������������������������������������������ 23 2.6 X-ray Mania������������������������������������������������������������������������ 24 3 R  adio-Euphoria ���������������������������������������������������������������������������� 29 3.1 Discovery of Radioactivity. Experiments of Henri Becquerel ���������������������������������������������������������������������������� 29 3.2 Discovery of Radium: Works of Pierre and Mari Curie�������� 33 3.3 Theory of Radioactivity: Works of Rutherford and Soddy���������������������������������������������������������������������������������� 38 3.4 Honoring the Pioneers of the Study of Radioactivity������������ 42 3.5 Radio-Euphoria�������������������������������������������������������������������� 44 3.6 Radium Water “Radithor”���������������������������������������������������� 51 4 From  Radio-Euphoria to Radio-Phobia �������������������������������������� 53 4.1 Radiation Exposure Before the Discovery of Radiation�������� 53 4.2 Attitude Towards Radiation Before World War II���������������� 55 xix

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4.2.1 Experiments on Oneself ���������������������������������������������� 56 4.2.2 Marie Curie������������������������������������������������������������������ 56 4.2.3 Thomas Edison and Clarens Dally�������������������������������� 57 4.2.4 Elizabeth Fleishman ���������������������������������������������������� 58 4.2.5 Nikola Tesla ���������������������������������������������������������������� 58 4.2.6 Emil Grubbe���������������������������������������������������������������� 59 4.3 The Eben Byers Case���������������������������������������������������������������� 61 4.4 The Case of “Radium Girls” ���������������������������������������������������� 64 4.5 Nuclear Bombardment of the Japanese Cities�������������������������� 67 4.5.1 The Damaging Effects of a Nuclear Explosion�������������� 68 4.5.2 Nuclear Bombs������������������������������������������������������������ 71 4.5.3 Reaction to the Bombing in Japan�������������������������������� 74 4.5.4 Reaction to the Bombing in the World������������������������ 76 4.5.5 Reaction to the Bombing in the USSR������������������������ 77 4.6 Radiation Events in the USA���������������������������������������������������� 78 4.6.1 Otto Frisch������������������������������������������������������������������ 79 4.6.2 Harry Daghlian, Jr.������������������������������������������������������ 79 4.6.3 Luis Slotin�������������������������������������������������������������������� 80 4.7 Adventure of the Japanese Fishing Boat Fukuryu-Maru������������ 82 4.8 Reaction of the Society������������������������������������������������������������ 90 4.9 Major Accidents ���������������������������������������������������������������������� 92 4.9.1 Accident in Windscale (Great Britain)�������������������������� 92 4.9.2 Radiation Events in Southern Ural (Former USSR)������ 95 4.9.3 Three-Mile-Island Accident (USA) ������������������������������ 97 4.10 Horror Films���������������������������������������������������������������������������� 99 4.11 The Modern Manifestation of Radiophobia���������������������������� 101 4.11.1 Transportation of Uranium Ore and Depleted Uranium Hexafluoride, 2019–2022 �������������������������� 101 4.11.2 Nuclear Repository in Moscow, Summer-Autumn 2019�������������������������������������������������������������������������� 102 4.11.3 Explosion near Severodvinsk in Nyonoksa, August 8, 2019�������������������������������������������������������������������������� 103 4.11.4 Ruthenium-106 Release at Mayak, Late September 2017�������������������������������������������������������������������������� 104 4.11.5 Radioactive Rocks in the Grand Canyon, USA, February 2019������������������������������������������������������������ 105 4.11.6 Swear Word = 1000 Röntgen ������������������������������������ 105

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5 The  Effect of Radiation on a Living Organism, View from Outside�����������������������������������������������������  107 5.1 What Is “Dose” and What Is “Effect” ������������������������������������ 107 5.1.1 What Is “Dose”���������������������������������������������������������� 108 5.1.2 What Is “Dose Rate”�������������������������������������������������� 109 5.1.3 What Is “Effect” �������������������������������������������������������� 110 5.2 Dependence “Dose–Effect”���������������������������������������������������� 110 5.3 How the Dose-Response Relationship Is Measured���������������� 114 5.4 Basics of the Epidemiological Method������������������������������������ 115 5.4.1 Risk Calculation�������������������������������������������������������� 116 5.4.2 On Animal Research�������������������������������������������������� 117 5.4.3 On Human Studies���������������������������������������������������� 119 5.5 Radiosensitivity of Tissues, Organs, and Organisms �������������� 122 5.6 Models of the Action of Low Doses of Radiation ������������������ 124 5.6.1 Linear No-Threshold Model�������������������������������������� 124 5.6.2 Dose and Dose-Rate Effectiveness Factor (DDREF)������ 129 5.6.3 Other Models������������������������������������������������������������ 130 5.7 Threshold Doses and Radiation Safety Standards�������������������� 131 6 The  Effect of Radiation on a Living Organism, the View from Inside�������������������������������������������������������  137 6.1 Radiobiological Paradox �������������������������������������������������������� 137 6.2 Radiation Targets in a Living Cell������������������������������������������ 138 6.2.1 Living Cell ���������������������������������������������������������������� 138 6.2.2 Molecules of Deoxyribonucleic Acid” (DNA)������������ 140 6.2.3 Molecules of Ribonucleic Acid (RNA) ���������������������� 142 6.2.4 Genes������������������������������������������������������������������������ 143 6.2.5 Cell Division�������������������������������������������������������������� 144 6.2.6 Cell Cycle������������������������������������������������������������������ 145 6.2.7 Epigenetics���������������������������������������������������������������� 146 6.3 Disorders in the Genetic Apparatus. Mutations, Mutagenesis ���� 149 6.3.1 Mutations������������������������������������������������������������������ 149 6.3.2 Mutagenesis �������������������������������������������������������������� 152 6.4 What Cancer Is���������������������������������������������������������������������� 153 6.5 The Effect of Ionizing Radiation on Biological Structures������ 157 6.5.1 Direct Action ������������������������������������������������������������ 157 6.5.2 Indirect Action���������������������������������������������������������� 159 6.6 Bystander Effect and Genome Instability�������������������������������� 161

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6.7 What Are “Low Doses” and What Are “Low Dose Rates”������ 162 6.7.1 What Are “Low Doses”���������������������������������������������� 162 6.7.2 What Are “Low Dose Rates”�������������������������������������� 165 6.8 More About Dose Rate���������������������������������������������������������� 166 7 Safety  of Low Radiation Doses�������������������������������  169 7.1 Cohorts of Irradiated People�������������������������������������������������� 169 7.2 Radium Girls ������������������������������������������������������������������������ 170 7.3 Experiments on Humans in the United States and USSR������ 172 7.3.1 Experiments on Humans in the United States������������ 172 7.3.2 Experiments on Humans in the USSR ���������������������� 174 7.4 Victims of the Atomic Bombardment of Hiroshima and Nagasaki�������������������������������������������������������������������������������� 176 7.4.1 Atomic Bombardment����������������������������������������������� 176 7.4.2 Doses ������������������������������������������������������������������������ 177 7.4.3 Health������������������������������������������������������������������������ 181 7.4.4 Genetic Consequences ���������������������������������������������� 184 7.4.5 Hibakusha Twice�������������������������������������������������������� 184 7.4.6 Conventional Bombardment�������������������������������������� 185 7.5 Radiologists and Patients�������������������������������������������������������� 186 7.5.1 Radiologists���������������������������������������������������������������� 186 7.5.2 Patients���������������������������������������������������������������������� 187 7.6 Chernobyl: Liquidators and Population��������������������������������� 188 7.6.1 Accident�������������������������������������������������������������������� 188 7.6.2 Terrain Pollution�������������������������������������������������������� 191 7.6.3 Doses ������������������������������������������������������������������������ 192 7.6.4 Health������������������������������������������������������������������������ 193 7.6.5 Psychological Trauma of the Population �������������������� 195 7.6.6 Other Points of View������������������������������������������������� 196 7.6.7 Public Opinion���������������������������������������������������������� 198 7.7 Fukushima: Liquidators and Population�������������������������������� 200 7.8 Nuclear Industry Workers������������������������������������������������������ 203 7.9 Population and Personnel in the Nuclear Weapons Testing Areas�������������������������������������������������������������������������������������� 204 7.9.1 Nuclear Test Sites in the World���������������������������������� 204 7.9.2 Population of Kazakhstan: Semipalatinsk Test Site ���� 205 7.9.3 United States, Nevada Test Site���������������������������������� 209 7.9.4 Pacific Islanders���������������������������������������������������������� 210 7.9.5 Personnel�������������������������������������������������������������������� 212

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7.10 Crews and Passengers of Long-Distance Flights and Astronauts������������������������������������������������������������������������������ 213 7.10.1 Cosmic Rays�������������������������������������������������������������� 213 7.10.2 Radiation Condition in Space������������������������������������ 215 7.10.3 Radiation Environment for Flights of Airliners���������� 217 7.11 Population Living in the Area of Nuclear Facilities ���������������� 220 7.12 Population in Areas with a High Background������������������������ 221 7.12.1 The Areas with a High Background���������������������������� 221 7.12.2 China, District Yangjiang ������������������������������������������ 222 7.12.3 India, District Karunagapally ������������������������������������ 223 7.12.4 Iran, District Ramsar�������������������������������������������������� 223 7.12.5 Brazil, District Guarapari ������������������������������������������ 225 7.12.6 Life in High Mountain Areas ������������������������������������ 225 7.13 Conclusion���������������������������������������������������������������������������� 227 8 The  Usefulness of Radiation Low Doses: Radiation Hormesis���������������������������������������������������  231 8.1 What Is “Hormesis” �������������������������������������������������������������� 231 8.2 Chemical Hormesis���������������������������������������������������������������� 232 8.3 Law of Tolerance�������������������������������������������������������������������� 235 8.4 Radiation Hormesis �������������������������������������������������������������� 236 8.4.1 T.D. Luckey �������������������������������������������������������������� 236 8.4.2 Justification of the Idea of Hormesis�������������������������� 237 8.5 Experiments on Bacteria, Tissue Cultures, Rodents, etc.�������� 240 8.6 Survivors of the Hiroshima and Nagasaki Nuclear Bombardment������������������������������������������������������������������������ 242 8.6.1 Cancer ���������������������������������������������������������������������� 242 8.6.2 Leukemia Response���������������������������������������������������� 243 8.7 Occupational Exposure���������������������������������������������������������� 244 8.7.1 Nuclear Shipyard Workers������������������������������������������ 245 8.7.2 Health of Shipyard Workers �������������������������������������� 247 8.7.3 Radiologists���������������������������������������������������������������� 248 8.7.4 Nuclear Industry Workers������������������������������������������ 249 8.7.5 Chernobyl and Fukushima ���������������������������������������� 250 8.7.6 Military Observers ���������������������������������������������������� 250 8.7.7 Radiation Effects on Long-Distance Flight Crews������ 251 8.7.8 Radiation Effects on Cosmonauts������������������������������ 251 8.8 Environmental Exposure�������������������������������������������������������� 253 8.8.1 Patients of Radiation Medicine���������������������������������� 253

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8.8.2 Population in the Zones of Nuclear Weapons Tests ���� 253 8.8.3 Population Near Nuclear Facilities ���������������������������� 255 8.8.4 Life in Conditions of Increased Natural Radiation Background���������������������������������������������������������������� 256 8.9 Treatment with Low Doses of Radiation�������������������������������� 257 8.10 COVID-19 and Radiation ���������������������������������������������������� 260 8.11 Radioadaptive Response ���������������������������������������������������� 262 8.12 Conclusion������������������������������������������������������������������������ 265 9 Radon  and Radon Therapy �������������������������������������������������������� 267 9.1 Introduction���������������������������������������������������������������������� 267 9.2 Radon and Its Role in Radio-euphoria ������������������������������ 269 9.3 Radon Properties���������������������������������������������������������������� 272 9.4 Radon Concentration in Atmosphere�������������������������������� 274 9.5 Radon Concentration in Mines������������������������������������������ 276 9.6 Indoor Radon Concentration�������������������������������������������� 277 9.7 Radon in Multistory and High-Rise Buildings ������������������ 280 9.8 Radon in Underground Areas�������������������������������������������� 281 9.9 On the Relationship of Dose Rate with Radon Concentration�������������������������������������������������������������������� 281 9.10 About the Cleaning System of the Lungs��������������������������� 283 9.11 The Biological Effect of Radon������������������������������������������ 284 9.12 The Role of Smoking���������������������������������������������������������� 289 9.13 Radon and Animals Living in Underground Burrows�������� 291 9.14 Radon Therapy������������������������������������������������������������������ 293 9.14.1 What Is Radon Therapy, and from What Diseases It Helps�����������������������������  293 9.14.2 Where the Famous Radon Resorts Are���������  295 9.14.3 Real Results of Radon Treatment���������������  297 9.14.4 Possible Mechanism of Therapeutic Action of Radon�����������������������������  298 10 The  Necessity of Low Radiation Doses: Experiments in Underground Laboratories �������������������������������������������������������� 301 10.1 History of the Question ���������������������������������������������������� 301 10.2 Underground Low-Background Laboratories �������������������� 303 10.3 Living Organisms in Underground Laboratories���������������� 309 10.4 Underground Medicine������������������������������������������������������ 310 10.5 Life in Conditions of Especially Low Background�������������� 311 10.6 Conclusion������������������������������������������������������������������������ 316

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11 What  Is More Dangerous, What Is More Terrible?�������������������� 317 11.1 Comparison of Various Types of Hazards �������������������������� 317 11.1.1 Types of Hazards to Be Compared����������  318 11.1.2 Compared Parameters�������������������  320 11.1.3 Manifestation of the Different Sources of Danger����������������������������  320 11.1.4 For How Long Is It Correct to Compare the Risk������������������������������  321 11.2 Victims of Chemistry �������������������������������������������������������� 322 11.3 Air Pollution���������������������������������������������������������������������� 325 11.4 Smoking���������������������������������������������������������������������������� 328 11.4.1 Passive Smoking������������������������  330 11.5 Alcohol������������������������������������������������������������������������������ 330 11.6 Drug Abuse������������������������������������������������������������������������ 332 11.7 Medical Errors ������������������������������������������������������������������ 332 11.8 Victims of Traffic Accidents������������������������������������������������ 333 11.9 Victims of Terrorism���������������������������������������������������������� 334 11.10 Victims of Fire ������������������������������������������������������������������ 336 11.11 Loss of Life Expectancy������������������������������������������������������ 336 11.12 Radiation Events and Their Victims ���������������������������������� 339 11.13 Conclusion������������������������������������������������������������������������ 342 12 Conclusion:  It Is High Time to Move Back—From Radiophobia to Radio-Euphoria������������������������������������������������ 345 12.1 Expedition to the Epicenter of a Nuclear Explosion ���������� 345 12.2 Radiation Background Monitoring (If the War Starts Tomorrow)������������������������������������������������������������������������ 348 12.2.1 Europe�������������������������������  351 12.2.2 United States��������������������������  352 12.2.3 Russia�������������������������������  355 12.3 About Monitoring Systems������������������������������������������������ 357 12.4 Conclusion������������������������������������������������������������������������ 358 A  ppendix���������������������������������������������������������������������������������������������� 361 List of Recommended Literature�������������������������������������������������������� 369

1 The World in the Era of Great Discoveries: X-rays and Radioactivity

There is no need to prove that modern science is of undoubted interest to society. Messages even about minor events in the world of science are constantly published. On television, there are not only special programs but also entire scientific channels that transmit information about scientific achievements around the clock. However, this was not always the case. At the end of the XIX century, there was no radio, no television, and even less the Internet; the population received the main information about events around them from newspapers. However, most of the population of many countries of the world was illiterate. Therefore, newspaper reports were available to a narrow circle of educated people. In those days, the general public fed mainly on rumors and, as a rule, knew nothing about the work of scientists, engineers, and inventors until their work gave some result that directly affected people’s lives: a steam engine, a locomotive, a telephone, an electric light bulb. Though, several discoveries in the history of science were made at the very end of the XIX century and immediately or rather quickly aroused unprecedented public interest. This refers to the discovery of previously unknown rays. At the end of 1895, the German scientist W.C. Röntgen (Fig. 1.1a) discovered radiation that penetrates well through opaque barriers, which in Germany and Russia began to be called Röntgen rays, and in the rest of the world, as Röntgen himself called it, X-rays. A few months later, the French scientist A.H. Becquerel (Fig. 1.1b) discovered the radiation of uranium. For some time after its discovery, this radiation was called Becquerel rays or uranium rays. Even before the end of the century, the Curies discovered that in addition to uranium, thorium also has the same property, which they called © The Author(s), under exclusive license to Springer Nature Switzerland AG 2023 I. Obodovskiy, From Radio-phobia to Radio-euphoria, Springer Praxis Books, https://doi.org/10.1007/978-3-031-42645-2_1

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Fig. 1.1  Wilhelm Conrad Röntgen 1900—left, and Antoine Henri Becquerel, 1905— right. (a) Röntgen. Figure from X-ray, Wikipedia—https://en.wikipedia.org/wiki/X-­ray. Public domain. (b) Becquerel. Figure from Henri Becquerel, Wikipedia—https://en.wikipedia.org/wiki/Henri_Becquerel. Public domain

radioactivity, and when a new radioactive element, radium, was discovered, a million times more active than uranium, the surge of interest in this discovery was reminiscent of the same violent reaction that accompanied the discovery of Röntgen. In addition to the works of Röntgen, which instantly caused a stir, the invention of the radio must also be mentioned, which also immediately aroused great interest. The announcement of the possibility of telegraphing without wires appeared only a year after the amazing news about X-rays, and it was radiation again, this time “electric beams.” The discoveries of new radiations have stunned the world. The reaction to Röntgen’s discovery was instantaneous; it gave rise to a state of society that can be called X-ray mania. The manifestations of X-ray mania are described in Chap. 2. The amazing properties of the radioactive emissions of uranium and, mainly, radium became known to society with some delay. Still, they made an equally strong impression and gave rise to a state that can be called radio-­ euphoria. How this condition arose and manifested itself is described in detail in Chap. 3. Both discoveries were made by accident, but the logic of the development of science, the state of the industry, and society shows that if Röntgen and Becquerel had not stumbled upon these radiations, then the discoveries would

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still have taken place a little later, by themselves or by other scientists, but soon enough. It is known that the famous scientists William Crookes, Nikola Tesla, Philip Lenard, and, less known the Ukrainian Ivan Pulyui, who worked in Vienna, and even Heinrich Hertz himself, observed X-rays before Röntgen. Still, it did not occur to them that they were dealing with a new phenomenon, and the same thing happened with many other discoveries and inventions. There were a lot of scientists and inventors who aimed at the new. Various sources give different names of the inventors of the telegraph, telephone, light bulb, radio, airplane, and many other significant achievements of the human mind. By this time, the pressure of religious dogmas had been overcome. The researchers acknowledged that humanity still does not know much. Human curiosity and the needs of society have contributed to the development of science and technology. What was this special state of society that gave rise to these great discoveries? Historians of science are trying to explain why after the fires of the Inquisition, after the plague that devastated Europe, after centuries of religious wars in Europe religious dope was thrown off very quickly in a historical perspective, and great science and advanced technologies arose. Why was such a breakthrough in economic success made in an extremely short time? At the same time, historians are trying to understand why the previously prosperous Chinese, Indian, and Arab civilizations did not make such a breakthrough, why the perfected and aesthetically impeccable ways of expression ceased to satisfy poets, artists, and composers. Different answers to these questions can be found in the book of the historian Yuval Noah Harari “Sapiens. A Brief History of Humankind,” in the book of science journalist Nicholas Wade “Inconvenient Legacy,” in the book of sociologist and political scientist Jack Goldstone “Why Europe? The Rise of the West in world history. 1500-1850.” Well-known American author Jared Diamond in the book “Guns, Germs, and Steel: The Fates of Human Society” tried to find an answer, and so on. Inquisitive readers will find answers to some of their questions in these books. Here I present only a brief picture of the world at the turn of the century. The end of the XIX and the beginning of the XX centuries were relatively favorable for humankind. The great wars of the XIX century have died down, and people have not yet guessed about the world wars of the XX century. True, there have apparently never been entirely peaceful years on Earth, and now, the Anglo-Boer War was going on in South Africa (1899–1902), and in the Far East, shots were fired in the American-Philippine war (1899–1902), but all this happened on the periphery of the civilized world, and in Europe and the United States, it was relatively calm.

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Western civilization, after the gloomy millennium of the Middle Ages, having gone through the periods of the Renaissance and Enlightenment, has created a very attractive world. The scientific and technical achievements of European civilization and its incarnation in North America determined the further development of all mankind for many decades. The time of the late XIX—early XX centuries in Europe was deservedly called “Belle Époque.” In the United States, after the Civil War, a period of rapid economic and population growth began, called the “Gilded Age” (1876–1914), and in the art of Russia, the period at the turn of the century was called the “silver age,” it would, of course, also be called the golden age, but the definition of “golden age” was already taken by the Pushkin period. Stefan Zweig in the book “Yesterday’s World. Memoirs of a European” calls the era before the First World War (before 1914) “the golden age of reliability.” Europe slowly overcame the consequences of the Middle Ages, until suddenly, in the XVIII century, an explosive industrial development began, called the Industrial Revolution. Historians divide this revolution into two stages: the first industrial revolution, characterized mainly by the appearance of steam engines (James Watt, first patent 1775). This led to a massive transition from manual to machine labor, from manufactory to factory. The second stage is called the technological revolution, it covers the second half of the XIX—early XX centuries. The industry introduced new conveyor production, electricity played an increasingly important role, and the production of steel and various chemicals was mastered. Most of these technical advances have been based primarily on scientific research and discoveries. At the end of the XIX and the beginning of the XX century, revolutionary changes took place in transportation methods. For thousands of years, people overcame any distance on land, either on foot or on horses, bulls, elephants, and camels. More recently, in 1812, the French army crossed Europe, reached Moscow, and then back mostly on foot. The cavalry, including the baggage trains, comprised almost a fifth of Napoleon’s army. The beginning of the technological revolution is attributed to the opening in 1869 of a transcontinental railroad that linked the Atlantic and Pacific coasts of the United States. A little later, the Trans-Siberian Railway was completed in Russia, which made it possible to close the connection between the same oceans, but through the Eurasian continent. In 1885, the first car with a four-stroke gasoline engine, built by the German inventor Karl Benz, drove through the streets of Mannheim, Germany (Fig. 1.2a).

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Fig. 1.2  The first car of Karl Benz, 1885 (left). The first flight of the Wright Flyer, December 17, 1903, Orville piloting, Wilbur running at wingtip (right). (a) The first car. Figure from Carl Benz, Wikipedia—https://en.wikipedia.org/wiki/Carl_Benz. Public domain. (b) The first airplane. Figure from Wright brothers, Wikipedia—https://en. wikipedia.org/wiki/Wright_brothers. Public domain

It took quite a bit of time, and in 1903 a stable, controlled horizontal flight in Kitty Hook Valley, North Carolina, USA, was made. It was the first flight of the “Flyer-1” aircraft, built by the brothers Orville and Wilbur Wright (Fig. 1.2b). Revolutions in industry, transport, and science and a radical change in socio-economic conditions were accompanied by a revolution in art. Having supplanted the classics in the last decade of the XIX—early XX centuries, a new artistic direction spread throughout the world, capturing all types of art, music, literature, architecture, decorative and applied and fine arts. The general name of the new direction is “modern.” In different countries, in relation to different types of art, the names differed, the most famous is “Art nouveau” or “Fin de siècle” in France and “Jugendstil” in Germany. During the time that a modern observer can capture, say, from the time of Ancient Greece, many artistic trends have changed in art. Art critics call Romanesque and Gothic styles Baroque, Classicism, Sentimentalism, Romanticism, Realism, Symbolism, etc, but in all styles in literature, the word was a word that carried a specific meaning, in music, there was harmony, and in painting and sculpture, the house was a house, a tree was a tree, and a person was a person. And suddenly, in the XIX century, the old forms ceased to satisfy artists, and a large number of new artistic trends appeared: impressionism, and then post-impressionism, surrealism, symbolism, acmeism, futurism, cubism, suprematism, abstractionism, and others. Artists and poets, in their manifestos, explained in detail why they considered it necessary to move further and further away from traditional realism and why new forms of expression were needed.

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The result of the revolution in painting is visible in Fig. 1.3. On the left is a reproduction of the famous painting of the Russian artist Ilya Repin “Reply of the Zaporozhian Cossacks,” and on the right is an abstract composition by Wassily Kandinsky, created already in the XX century, in 1910, but clearly showing the direction of the revolution in painting. At the turn of the century in the musical capital of the world, in Vienna, the era of the waltz king Johann Strauss ended, and the era of the operetta king Imre Kalman began. Strauss waltzes still continued to circle Europe, and the Argentine tango was already seeping from the streets and taverns of Buenos Aires into restaurants and dance halls in Europe and the USA. In the United States, at the end of the XIX century, new musical styles appeared due to the fusion of African rhythms and European harmony— blues, ragtime, and, finally, jazz. On December 28, 1895, a historical event influenced the cultural life of all subsequent times. On this day in Paris, on the Boulevard des Capucines, the first film screening was held in one of the halls of the Grand Cafe. Cinema has begun its triumphal march across the planet. Only enthusiasts were engaged in science in the XIX century. At that time, scientific activity was not the main source of material support for most scientists. As a rule, scientific research was carried out at universities, and scientists earned their living by teaching, and the main characters of our subsequent narrative were engaged in research in the interval between lectures, laboratory, and seminar classes. Specialized scientific institutes have just begun to appear. Beginning in the middle of the XVIII century, a few scientific enthusiasts studied electricity, but the general public knew nothing about the laws of C.-A.  Coulomb or A.-M.  Ampère nor about the work of A.  Volta or

Fig. 1.3  Classical painting (Ilya Repin, Reply of the Zaporozhian Cossacks) and the first abstract watercolor (W. Kandinsky, 1910). (a) Ilja Repin. Figure from Ilya Repin—https:// en.wikipedia.org/wiki/Ilya_Repin. Public domain. (b) Kandinsky. Figure from Wassily Kandinsky—https://en.wikipedia.org/wiki/Wassily_Kandinsky. Public domain

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H. Oersted’s discovery. The role of M. Faraday’s works on electromagnetism and J.C. Maxwell’s equations, which laid the foundations of modern classical electrodynamics, became obvious only after the advent of the telegraph (S. Morse, 1840), the telephone (A. Bell, 1876) and, especially, the incandescent light bulb (T. A. Edison, 1879). Its appearance was the result of the work of several scientists at once, but it was Edison who could make incandescent lamps massive. Edison is the author of over 1000 inventions. He improved the telegraph and telephone, invented the phonograph (1882), and built the world’s first public power plant (1882). Let’s add Nikola Tesla to this list of the great scientists and inventors who worked at that time (Fig. 1.4). During the same period, the first step in developing quantum concepts was taken. In 1900, Max Planck solved the long-unsolvable problem of energy distribution in the spectrum of an absolutely black body by introducing the famous “quantum of action.” Planck’s merits were awarded the Nobel Prize in 1918. At the end of the XIX century, the works of G. Lorentz (Nobel Prize in Physics in 1902) and A. Poincaré laid the foundation for the theory of relativity, finally formulated in 1905 by A.  Einstein. The theory of relativity and quantum mechanics, born at the turn of the century, determines the development of physics, chemistry, astronomy, and many other sciences up to the present day.

Fig. 1.4  Portrait of T.A. Edison, the work of the artist A.A. Anderson, 1890 (left) and a photo of N. Tesla, 1896 (right). (a) Edison—Figure from Thomas Edison. Wikipedia— https://en.wikipedia.org/wiki/Thomas_Edison. Public domain. (b) Tesla—Figure from Nikola Tesla. Wikipedia—https://en.wikipedia.org/wiki/Nikola_Tesla. Public domain

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In the second half of the XIX century, the rapid development of chemistry, both science and chemical technologies, and industries, became an important component of industrial transformation. Until the middle of the XVIII century, only 14 elements were known to chemists, and starting from 1750, the discovery of new elements has been going on almost continuously and evenly, of which 50 were discovered during the entire XIX century. There was a need to bring some order to this abundance. As a result in 1869, Russian scientist Dmitry Ivanovich Mendeleev proposed his periodic system of elements, which has withstood the test of time and remains valid up to the present. At the end of the XIX century, a new group of elements, inert gases, was discovered. The main role in this belongs to the Scottish scientist William Ramsay and the English scientist John Strutt, better known as Rayleigh. For this discovery, Ramsay received the Nobel Prize in Chemistry in 1904, and Rayleigh in the same year in Physics. The needs of industry led to the development of research in the field of catalysis, which made it possible to carry out many chemical processes on an industrial scale. New branches of the chemical industry appeared—the production of mineral fertilizers and aniline dyes. By the beginning of the XX century, synthetic dyes had almost completely replaced natural dyes. In 1867 Alfred Bernhard Nobel (Fig. 1.5) patented dynamite. Nobel held 355 different patents, of which dynamite is the most famous. Most of his

Fig. 1.5  The photo of Alfred Nobel, 1896. Figure from Alfred Nobel, Wikipedia— https://en.wikipedia.org/wiki/Alfred_Nobel. Public domain

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fortune, obtained, in particular, from the production of explosives and Nobel bequeathed to the establishment of prizes for achievements in physics, chemistry, medicine, literature, and for activities to strengthen peace. By now, the Nobel Prize, at least in the field of natural sciences, has become the most authoritative way to recognize the significance of scientific achievements. Biology also experienced revolutionary transformations. In 1859, Charles Darwin’s “On the Origin of Species” appeared with a detailed explanation of the concept of natural selection. The book “The Descent of Man,” published in 1971, finally laid the foundations for the theory of evolution. In 1866, Gregor Johann Mendel published his work “Experiments on Plant Hybridization” (Versuche über Pflanzenhybriden), which served as the basis for another revolutionary theory—the doctrine of heredity. The work was not noticed and appreciated by contemporaries, but in 1900 Mendel’s laws were rediscovered and confirmed by the works of Hugo De Vries and Carl Correns. Subsequently, a modern synthetic theory of evolution was formed due to the combination and reinterpretation of several provisions of classical Darwinism and new achievements in molecular genetics. To the achievements of biology of the described period, one must add the emergence of microbiology; Louis Pasteur published his main works in 1860–1870. In 1888, Heinrich Hertz (Fig. 1.6a) experimentally proved the existence of electromagnetic waves predicted by Maxwell and investigated their basic

Fig. 1.6  Heinrich Hertz, Alexander Stepanovich Popov, Guglielmo Marconi (from left to right). (a) Hertz—Figure from Heinrich Hertz, Wikipedia—https://en.wikipedia.org/ wiki/Heinrich_Hertz. Public domain. (b) Popov—Figure from Alexander Stepanovich Popov, Wikipedia—https://en.wikipedia.org/wiki/Alexander_Stepanovich_Popov. Public domain. (c) Marconi—Figure from Guglielmo Marconi, Wikipedia—https://en. wikipedia.org/wiki/Guglielmo_Marconi. Public domain

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properties. Hertz died in 1894 without completing his work. Hertz himself, apparently, did not really think about the possibility of using his discovery for signal transmission. However, this question has interested many other researchers. Hertz’s results became the basis of wireless communication that soon appeared. In different countries around the same time, many scientists were working on the creation of devices capable of transmitting signals without wires. In Russia, Alexander Stepanovich Popov (Fig. 1.6b) is considered the inventor of the radio. The Italian inventor Guglielmo Marconi (Fig. 1.6c) is better known in the world (Nobel Prize in Physics for 1909). In other countries, other people are called the inventors of the radio, and different dates are given for this invention. In the United States, Nikola Tesla is considered the inventor, in Germany—Heinrich Hertz, in France—Edouard Branly, in Brazil—Landel de Mour, in England—Oliver Joseph Lodge, and in India— Jagadish Chandra Bose. The discoveries of X-rays (Röntgen, 1895) and radioactivity (Becquerel, 1896), which will be described in detail in subsequent chapters, as well as the invention of radio, which marked the beginning of the second scientific revolution. The first is associated with the names of Copernicus, Galileo, and Newton. The second scientific revolution, which began with the discoveries of Röntgen and Becquerel, continued with the discovery of the electron by J.J. Thomson in 1897, the creation of quantum theory (M. Planck—1900, A. Einstein—1905) and the theory of relativity (A. Einstein—1905). Agree, it turned out to be an amazing time—at the turn of the centuries. We paid attention only to the technological and scientific achievements of this period in history, but there were also political ones. In July–August 1897, at the second congress of the Russian Social Democratic Party, a faction of “Bolsheviks” headed by Lenin stood out, influencing the entire history of the XX century. In the same year, at the end of August, the World Zionist Congress decided to establish the State of Israel. As the famous Zionist and brilliant writer and publicist Zeev Jabotinsky wrote “There are not often repeated epochs in the history of mankind, in which a shiver of impatience pierces the nations, like a young man awaiting the arrival of his beloved.” This was Europe at the end of the XIX century. Once again, we note the revolutionary character of this era, which, in particular, gave the world two great discoveries that brought many benefits to humankind, but also a big headache. The discoveries of X-rays and radioactivity were the product of revolutionary transformations at the turn of the epoch and, in turn, determined the nature of these transformations. This book is devoted to the impact on human health of new radiations discovered at the end of the XIX century.

2 X-ray Mania

2.1 Wilhelm Conrad Röntgen In October 1895, Wilhelm Konrad Röntgen, a fifty-year-old professor of physics at the University of Würzburg, began studying cathode rays. Röntgen’s interests were very diverse and covered many, mainly the most important, key physics questions. By the time we are describing, Röntgen had the reputation of one of the best experimenters in Europe. According to the scientists who worked with him, he was distinguished by a clear and simple set of experiments, high accuracy and reliability of the results obtained, and a comprehensive and subtle analysis of possible errors. Many of his works have become classics and have received various scientific awards. Shortly before Röntgen’s work with cathode rays started, he was elected director of the Institute of Physics at the University of Würzburg but continued his own research. Why did such an honored scientist searching for a research subject turn his attention to cathode rays?

2.2 Cathode Rays Cathode rays have played a special role in the history of physics, making it possible to solve some of the most important fundamental problems; works with cathode rays have been awarded several Nobel Prizes. Since ancient times, people have been interested in the processes that we now call electrical. The ancient Greek philosopher Plato wrote about the © The Author(s), under exclusive license to Springer Nature Switzerland AG 2023 I. Obodovskiy, From Radio-phobia to Radio-euphoria, Springer Praxis Books, https://doi.org/10.1007/978-3-031-42645-2_2

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miraculous ability of amber worn with fur to attract various materials. Let’s skip the long period of research on “resin” and “glass” electricity and turn to the work of the American scientist and politician Benjamin Franklin, who was interested in, among many other phenomena, atmospheric electricity and, in particular, the nature of lightning, what we can now call a gas discharge. These were deadly works; it is known that in 1753 the Russian scientist Georg Richman died while studying atmospheric electricity. Franklin did a lot for the doctrine of electricity. He experimentally proved the electrical nature of lightning, invented a lightning rod, proposed the now generally accepted designation of charged particles “+” and “-”, and exploded gunpowder with an electric spark for the first time. But lightnings are random and uncontrollable; it is very difficult to study electricity only on the example of lightning. The impetus for further research was given by the invention of the vacuum pump in the middle of the XVII century by Otto von Guericke. Reducing the pressure in vessels with the electrodes inserted there made it possible to study the gas discharge at lower voltages and in the laboratory’s wide range of pressures and gas composition. The first experiments were carried out in glass tubes. Since then, all gas-­ filled or vacuum devices began to be called tubes, and even a television cathode-­ray device, very little like a tube—a kinescope, which was the main version of the television screen for a long time before the advent of flat screens, was called a television tube. Many tubes, differing in shape, arrangement of electrodes, and sometimes only in gas pressure, were named after the scientists who worked with them. Geissler, Plücker, Gittorf, Lenard, and Crookes tubes are mentioned in the literature. An image of the Crookes tube is shown in Fig. 2.1. The German physicist and glassblower Heinrich Geissler, who worked at the University of Bonn, is considered the pioneer of gas discharge research in the laboratory. He really was both a physicist and a skilled glassblower. Geissler blew tubes of the most intricate shapes. Some are shown in Fig. 2.2. These beautifully luminous tubes were used as decorations, but Geisler also prepared serious scientific instruments. A beautiful glow appears when an electric voltage is applied to the electrodes soldered into a partially evacuated glass tube. The discharge is a thin cord if the gas pressure is not very low. The luminous cord blurs and expands when the pressure is reduced, and the glow fills the entire tube. This form of gas discharge is called a glow discharge. Modern neon advertising is the variant of a Geissler tube. The color of the glow is determined by the type of gas filling the tube. If the inner surface of

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Fig. 2.1  The scheme of the Crookes tube. A Maltese cross mounted in the tube casts a shadow on the luminescent wall of the tube, showing that the cathode rays propagate in a straight line. The approach of the magnet shifted the position of the shadow. Figure from Crookes tube. Wikipedia—https://en.wikipedia.org/wiki/Crookes_tube. Public domain

Fig. 2.2  Some of the Geissler tubes showing the glow of an electrical discharge in rarefied gases. The main purpose of the tubes shown is decorative. After about 50–60 years, such tubes began to be used for advertising. Figure from Geissler tube, Wikipedia—https://en.wikipedia.org/wiki/Geissler_tube. Public domain

the tube is coated with phosphor, and the gas contains mercury vapor, then these are fluorescent lamps. One of the first scientists to use Geissler tubes was the German physicist and mathematician Julius Plücker. At the University of Bonn, Plücker, first on his own and then with Johann Hittorf, conducted extensive and systematic

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studies of the luminescence of various substances in Geissler tubes. Geissler prepared tubes with a capillary section 1–2 mm in diameter, which sharply increased the intensity of the glow. To study the luminescence of vapors of liquid and solid substances, the tube could be placed in the flame of a gas burner. Historians of science argue that Yu. Plücker and J. Hittorf owe their success in experiments on the study of an electric discharge in gases to the experience and skill of the glassblower H. Geissler. The photos of the pioneers of the cathode ray investigations can be seen in Fig. 2.3.

Heinrich Geissler

Julius Plücker

Johann Hittorf

William Crooks

Fig. 2.3  The pioneers of cathode ray investigations. Figures from Wikipedia: (a) Heinrich Geissler—https://en.wikipedia.org/wiki/Heinrich_Geißler. Public domain. (b) Julius Plücker—https://en.wikipedia.org/wiki/Julius_Plücker. Public domain. (c) Johann Wilhelm Hittorf—https://en.wikipedia.org/wiki/Johann_Wilhelm_Hittorf. Public domain. (d) William Crooks—https://en.wikipedia.org/wiki/William_Crookes. Public domain

About Glassblowers The author has personal motives to pay special attention to the work of glassblowers. Both in my childhood and in my youth, I read a lot of books about scientists and science. I knew that many instruments for research in various fields of knowledge, especially at the initial stages of the development of science, were made of glass and the role of glassblowers was very important. Many scientists themselves have successfully worked with glass, an almost universal material for many physical devices. The cathode tubes evacuated to a certain pressure, which is discussed in this chapter, were sealed, and only after that, it was possible to continue working with them, and Röntgen soldered his tubes himself. Therefore, after graduating from the institute and starting to work at the Moscow Engineering Physics Institute department, I asked to study in a glass-­ blowing workshop. Quite a strange decision for a graduate engineer. The authorities were surprised but yielded to the pressure of the enthusiastic fool. I learned how to solder Geiger counters and how to blow out glass cryostats, and I did it willingly, but it didn’t come in handy for long. Home-made devices began to be replaced by factory-made ones, cryostats began to be made of stainless steel, and instead of glassblowing, welding and soldering had to be mastered. The need for glassblowing is gone, but the pleasure remains.

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The role of the glassblower, mechanic, and physicist G.  Geisler has already been mentioned. The role played by Rutherford’s glass blower Otto Baumbach, a German from Thuringia, is well known in the history of physics. For a very important experiment, Rutherford needed a glass vessel with a one-hundredth of a millimeter thick wall through which an alpha particle could pass. Otto Baumbach undertook to blow out a vessel with such a thin wall that it could withstand pressure differences. It was a case when the entire outcome of a fundamental scientific experiment depended on the fantastic skill of an artisan. As a result of this experiment, Rutherford reliably proved that alpha particles are the nuclei of the helium atom. However, at that time (1908), no one, even Rutherford, knew that the atom had nuclei, the nuclei in the structure of the atom had yet to be discovered. The same Rutherford would do this, but later, in 1912. The role of the glass blower in the works of the great Russian physicist Pyotr Leonidovich Kapitsa is also known. Working with liquid helium, Kapitsa could not complete the experiment because the helium evaporated before he could finish the experiment. The task was solved by Alexander Vasilievich Petushkov, a well-known throughout Moscow glass blower. He made a unique spherical four-­ walled vessel in which Petushkov blew four three-liter volume glass balls one inside the other. Then Kapitsa managed to carry out his famous experiments on superfluidity, which subsequently brought him the Nobel Prize. Petushkov also created a unique device for studying the phenomenon of superfluidity—a “spider” of the smallest, on the verge of possible, sizes of ordinary glass, the transparency of which was the main condition for the experiment.

Working with Geisler tubes, Plücker discovered that with a further decrease in pressure, the near-cathode dark space gradually expands, eventually occupies the entire tube, and a greenish glow appears on the surface of the glass tube near the anode—luminescence of the tube glass. Plücker also discovered that the glow’s position on the tube walls could be changed using a magnet. Plücker’s student J. Hittorf established that solid bodies placed near the cathode cast shadows on the luminous wall of the tube. This is seen in Fig. 2.1. In other experiments, it was shown that not only glass itself can glow in a tube, but also many other substances applied to the inner wall of the tube. The totality of the results obtained by many researchers showed that something incomprehensible and unknown is emitted from the cathode, spreads in an almost empty space, hits the tube’s glass, makes it glow, and then collects on the anode. Moreover, this unknown substance carried an electric current. In 1876 German scientist Eugen Goldstein named this mysterious substance cathode rays (Kathodenstrahlen). Finally, Philip Lenard, using a thin aluminum window, brought the cathode rays out and measured their range in atmospheric air. At the voltages with which Leonard worked, the range turned out to be about 8 cm.

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However, the idea of the existence of elementary “portions” of electricity has already been circulating among physicists. About a hundred years before the time described, Franklin guessed the “atoms of the electric fluid.” Clear quantitative grounds for such conclusions were given by Michael Faraday in his work on the study of electrolysis—the decomposition of substances under the influence of an electric current. The famous German physicist Hermann von Helmholtz gave a clear form to these ideas in 1881. In 1894, the Irish physicist George Stoney proposed to call the unit of electricity, which atoms gain or lose, an electron. It was assumed that studies of cathode rays would make it possible to approach the solution of the problem of the atom of electricity. Cathode rays were something fundamentally new, containing important information about the structure of matter. Many prominent physicists were engaged in their study, in addition to those mentioned, we will name only the most famous here: Heinrich Hertz, the same Hertz who discovered radio waves and whose name is the unit of frequency of the electric current, William Crooks, J.J. Thomson. Among scientists, the nature of cathode rays was hotly discussed. There were two theories. Crookes and some other physicists believed that this was a stream of particles, Hertz believed that these were waves of ether. Disputes settled by J.J. Thomson, who already, after the discovery of Röntgen, in 1897, measured the charge and mass of the particles that made up the cathode rays, and thereby discovered the electron. In several successive works, Thomson showed that not only cathode rays in tubes with a cold cathode but also particles emitted in the photoelectric effect and thermal emission processes are electrons. Soon A.  Becquerel showed that the beta particles of radioactive radiation are also electrons. Now it is clear why Röntgen turned his attention to cathode rays. He was always interested in new mysterious phenomena that his illustrious predecessors could not figure out.

2.3 Röntgen Experiments, History of Discovery Röntgen began experimenting with cathode rays in October 1895, more precisely at the end of October. Clarification is important here, since already on November 8 of the same year he stumbled upon a new phenomenon. That day he worked with several tubes—different shapes, with different electrode arrangements, with different residual gases. Historians of science cannot specify on which particular tube Röntgen observed the radiation that

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hit him for the first time, but it is obvious that he worked with a tube with a window that allowed the cathode rays to be brought out. The presence of rays in the atmospheric air near the tube was controlled using a paper screen covered with a layer of barium platinocyanide, which glows brightly greenishyellow when bombarded with cathode rays. The tube’s own glow interfered with observing the luminescence of the screen, and Röntgen covered the tube with a thick, opaque cardboard case. It is known that the historic event took place on November 8, 1895. At about 11 pm, Röntgen was alone in the laboratory. He turned off the light and was about to leave but noticed an incomprehensible glow. The glow came from a paper screen that lay on another table about three meters from the tube. This glow could not be excited by cathode rays in any way, they are not capable of traveling such distances in the air. It turned out that Röntgen had forgotten to turn off the electrical power to the tube. All night from November 8 to 9, 1895, Röntgen spent without sleep in his laboratory. Röntgen quickly established that the glow of the screen is caused by an invisible, hitherto unknown radiation that occurs in the tube and precisely in the place where the cathode rays fall. It turned out that the new radiation had significant penetrating power; it almost freely passed through boards, thick books, and layers of different materials. In the next seven weeks, Röntgen spent a detailed study of the phenomenon he had discovered. From the description of Röntgen’s wife, it is known that at that time, he rarely left the laboratory, that she brought him food, and that he often even spent the night there. Röntgen called the new radiation X-rays. Röntgen’s biographers pay attention to the thoroughness of preparing the data he obtained for publication. He sent articles about his experiments only after the final verification of the correctness and accuracy of the results. This time, too, doubts overcame the scientist. In a letter to one of his colleagues, he confessed “Even seeing with my own eyes how the rays pass through various objects, including my hand, I could not believe that I had not become a victim of some kind of deception.” That is why Röntgen worked alone, without telling anyone, even his assistants, about the discovery. Only around the end of November, Röntgen called his wife Berta to the laboratory; it was then that he took the first and subsequently famous X-ray of his wife’s hand with a wedding ring. On December 28, 1895, Röntgen presented information about his research under the title “On a new kind of rays” (Ueber eine neue Art von Strahlen) to the president of the Würzburg Physico-Medical Society. The article was accepted for publication in the Annals of the Society for 1895 and distributed

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Fig. 2.4  X-ray of Kölliker’s hand, made by Röntgen on January 23, 1896. Figure from Wilhelm Röntgen, Wikipedia—https://en.wikipedia.org/wiki/Wilhelm_Röntgen. Public domain

during the first days of January 1896. The Christmas holidays fell at that time, and no lectures or meetings were held. Röntgen made the first oral communication and, apparently, the only one on January 23, 1896, but much earlier, at the very beginning of January, Röntgen sent pictures taken in the rays he had discovered to several scientist friends. In particular, to Professor F. Exner from Vienna. It so happened that the photographs were immediately published in the newspaper Wiener Presse, so that by the time Röntgen spoke at a meeting of the Würzburg Physico-Medical Society, his sensational discovery was already known, and his speech aroused tremendous interest. After the report, Röntgen asked permission from the famous anatomist Albert von Kölliker to take a photograph of his hand (Fig. 2.4). When, after the development of the plate, the photo was shown to the audience, it caused a storm of applause. It was hailed as “a moment of true historical significance.” The photograph of Dr. Kölliker’s hand, also with a wedding ring, is similar to the first photograph of the hand of Röntgen’s wife, Frau Bertha, but much clearer. In subsequent publications, these photographs are often confused.

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Röntgen discovered X-rays by accident. If he first turned off the power to the tube, and then the light in the laboratory, if the screen with the light composition were not on the table, but in the box, if … One could name many more such “ifs,” and the opening would not have taken place that evening, and then history would have taken a different path, but what happened that happened. According to the famous Scottish physician, President of the Society for the History of Medicine of the Royal Society of Medicine, E.A.  Underwood, “The stage was already set for the discovery of X-rays, and fate chose Röntgen as the key character in this play.” Now we know that the radiation discovered by Röntgen was recorded before him by at least several physicists: the famous scientists W.  Crookes, F. Lenard, N. Tesla, and G. Hertz, as well as the less famous, but who did a lot when working with cathode rays, and then with the newly discovered radiation, Ivan Puluj, a Ukrainian by birth, who worked in Vienna, but only Röntgen realized that he was dealing with a new phenomenon and began to study it. So, the glory of the discoverer belongs to him by right. After the publication of Röntgen’s article, at least a dozen statements were made, the authors claiming to have discovered X-rays. Of the major physicists listed above, only F. Lenard did not recognize Röntgen’s priority.

About Philipp Lenard and His Attitude to X-rays One of the physicists who worked a lot with cathode rays, Philip Lenard, was a talented experimenter. He rightfully received the Nobel Prize in Physics in 1905 for his work with cathode rays. In particular, Lenard discovered the basic law of the photoelectric effect: The maximum speed of emitted electrons does not depend on the illumination but depends only on the frequency of the incident light, which contradicted what was known at that time, the laws of electrodynamics. The explanation of the discovered pattern formed the basis of the quantum theory published by Einstein in 1905. For this work, and not for the famous theory of relativity, Einstein received the Nobel Prize in 1921. Working with cathode rays, Lenard first brought these rays out of the tube into the surrounding air, using a thin aluminum window for this. In these studies, Lenard discovered that some rays passed through his hand and that they illuminated the photographic plate. Lenard was very close to the discovery of X-rays, but he did not understand what he was observing and did not notice what Röntgen paid attention to. In his younger years, Lenard was an assistant to Heinrich Hertz, a Jew by birth, it is important to note this here, and after the early death of Hertz in 1894 he published a collection of his works. And quite cordial, his relationship with Einstein was at an early stage. When Einstein published his quantum theory explaining the laws of the photoelectric

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effect, Lenard sent him a benevolent letter of congratulations. In turn, Einstein highly appreciated Lenard’s experimental skill and called him a great master and genius, although he criticized and even ridiculed Lenard’s theoretical ideas. However, later Lenard was seized by nationalist sentiments, which intensified due to the disappointment of the Germans with the results of the 1st World War and the subsequent devastation. His vanity was wounded by the unflattering remarks of Albert Einstein about his theoretical views. Perhaps the annoyance that he missed the great discovery, although close to it, also played a role. As a result, by the 1920s, Lenard had become a consistent nationalist and anti-Semite. He began to support Adolf Hitler from the first years of his appearance in the political arena, and after the Nazis came to power, he became the head of the so-called Aryan physics. The contribution of Einstein and his supporters to science he now called “Jewish physics.” Having received many different honors and awards, Lenard, however, was not satisfied. He believed that as a result of the intrigues of Jewish or pro-Jewish scientists, he was underestimated, that he deserved more fame, that his true place was in the Einstein-Becquerel-Curie series. As a result, Lenard took up arms against Jewish, French, and Polish Nobelists (Albert Einstein, Marie Curie, Jean Perrin). He created a four-volume textbook “German Physics,” which completely lacked any mention of Einstein and Röntgen, quantum mechanics, and the theory of relativity. Lenard explained his negative attitude towards Röntgen, who was not a Jew, by the fact that: “... he was friends with the Jews and acted like them.” Already at the end of his life, in September 1945, after the defeat of Germany in the 2nd World War, being in exile in the small town of Messelhausen, answering the questions of Colonel Etter of the American Army (Lt. Col. Lewis E. Etter) about the discovery of X-ray radiation, Lenard said “I am the mother (Ich bin die Mutter ...) of the X-rays. Just as the midwife is not responsible for the birth, so Röntgen is not responsible for the discovery of X-rays, since I did all the main work. Without me, Röntgen’s name no one would know today.”

According to historians of science, in the first year after the discovery, about a thousand articles and dozens of books about the new radiation were published. Röntgen himself was engaged in X-rays for a little over a year, until March 1897, and published only three relatively small articles about them, but, as the future assistant of Röntgen, the Russian scientist A.F. Ioffe wrote: “In three small articles published within one year, such an exhaustive description of the properties of these rays is given that hundreds of papers that followed over the course of 12 years could neither add nor change anything significant.” Then Röntgen lost interest in this problem and told his colleagues: “I have already written everything, do not waste your time.” Röntgen, perhaps, slightly exaggerated, as did Ioffe, the exhaustive nature of his research. His work was just the beginning.

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Already in 1902, the British scientist Charles Barkla began the research that led to the discovery of characteristic X-rays that brought the author the Nobel Prize in Physics in 1917. The young English physicist Henry Moseley, who had every reason to become a great scientist, but did not have time to become one, since he died in the First World War in 1915, established in a series of brilliant experiments published in 1913, the fundamental relationship between the frequency of the spectral lines of the characteristic X-ray radiation and the atomic number of the emitting element. This relationship is called Moseley’s law. The German physicist Max Laue received the Nobel Prize in Physics in 1914 for discovering X-ray diffraction by crystals. The Englishmen William Henry Bragg-father and William Lawrence Bragg-son received the Nobel Prize in Physics in 1915 for developing X-ray diffraction analysis. In 1924, the Swedish scientist Manne Siegbahn received the Nobel Prize in Physics for research in the field of X-ray spectroscopy. Investigating the scattering of X-rays, the American scientist Arthur Compton discovered the effect named after him. This achievement was also awarded the Nobel Prize in 1927. Only the most significant works carried out after Röntgen using the radiation he discovered are listed here, but it should be noted that all of them (works, not awards) are shifted in time relative to the discovery of X-rays by 5 or even 10 years. Immediately after the publication of Röntgen’s main articles, adding anything to his research was difficult. The discovery of new, with amazing properties, rays stirred up the activity of many, sometimes naive, sometimes unscrupulous researchers in an attempt to discover some more new rays. The best known are the first open and then safely closed N-rays of Prosper-René Blondlot and the F-rays of Giulio Ulivi. Sooner or later, it turned out that these rays were the fruit of a misunderstanding or a mistake.

2.4 The Reaction of the Press and Society During January 1896, the news of the revolutionary discovery of the professor from Würzburg spread around the world at a speed never seen before. The newspapers of the major cities of Europe and America reported news of the mysterious rays even before the original report of the discovery appeared in the Würzburg newspaper General Anzeiger.

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On January 3rd, 1896, subscribers of the “Wiener Presse” received a newspaper issue with an article by the newspaper’s publisher Z.K. Lecher. Other newspapers reprinted the “Wiener Presse” report. On January 5th it appeared in one of the Berlin newspapers, and on January 6, a short note about the new discovery flashed in the London “Standard.” In the evening of the same day, the London Telegraph Agency sent a telegram to many foreign press agencies. In mid-January 1896, Röntgen’s article “On a new kind of rays” was finally published, and the issue of the journal with this article was sold out within one day. There were so many people who wanted to read the article that it had to be printed as a separate brochure, which was published in five editions in the first month. Within a short time, the famous paper was translated into many European languages; on January 23, 1896, it appeared in England in the scientific journal Nature, and on February 8, in France, in L/Eclairage Electrique. The fifth edition, which appeared after a few weeks and which carried a red wrapper with the inscription, “Contains the New discovery of Professor Röntgen in Würzburg,” stated “This monograph also appears in English, French, Italian and Russian.” The historian of science L. Badash compares the reaction of the press to the discovery of Röntgen with the reaction to the message about the creation of an atomic bomb that appeared 50 years later. The peculiarity of the discovery of Röntgen and the level of development of science and technology of that time made it possible to very quickly repeat, verify and confirm the results of Röntgen in many laboratories worldwide. It is important that Röntgen’s articles did not contain mathematical formulas, they were easily understood even by non-specialists, including reporters and the general public. This contributed to the rapid dissemination of information about new rays. The greatest interest was aroused by the ability of X-rays to see the inside of the human body. The prospects of using the new radiation in medical diagnostics became clear almost immediately. In the first few weeks, X-rays made it possible to find foreign metal objects, bullets, a knife fragment, etc. in the body. As the famous Russian radiologist Professor M.I.  Nemenov wrote “Before the discovery of X-rays, anatomy was the science of the structure of a dead organism. Anatomy was studied only on corpses.” The use of X-rays made it possible to combine the anatomy and physiology of a living organism. Somewhat later, it became clear that X-rays can be useful not only in diagnosis but also in therapy. Then it became possible to study the structure and composition of substances with the help of new radiation—numerous analytical applications appeared.

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2.5 Something Else About Röntgen Of course, Röntgen was a great scientist, but a few words must also be said about Röntgen’s human qualities. It is known that he was a rather modest person but with a complex character. He refused to take out a patent for the radiation he discovered, believing that the whole world should benefit from his discovery. In 1901, Röntgen was awarded the Nobel Prize in Physics, the first prize of the newly established prize fund. With this award, the Nobel Committee set the bar for the level that should be met by the achievements marked by the Nobel Prize, and then this level was maintained, and now this award has become the most authoritative award in the world, but at the time of Röntgen, the future of this prize was not yet known. Maybe that’s why, but mainly showing his character, Röntgen refused to go to Stockholm for the ceremony, citing business. An explanation came from Sweden that this highest prestige award is presented at a state ceremony in the presence of high-ranking officials personally by His Majesty the King of Sweden. To this, Röntgen replied that if the king needed him, then let him come to him. The prize was sent to him by mail. So Röntgen reacted not only to a foreign, Swedish king but also to his own, German. This is written by X-ray assistant Russian scientist A.F. Ioffe, who trained with Röntgen in Munich. “Wilhelm II, when visiting the German Museum in Munich, after listening to Roentgen's explanations for the physics department, tried to explain the artillery to Röntgen in the same way, but could not say anything except the well-known trivial phrases. Röntgen directly told him so, after which Wilhelm, turning away, immediately left, offended in his pride of a military specialist.” When the Prince Regent of Bavaria awarded the scientist a high Order for scientific achievements, which gave him the right to a title of nobility and, accordingly, to add the particle “von” to his surname, Röntgen accepted the Order but refused the noble honor. Röntgen was invited by many universities in Germany, but he continued to work in Würzburg, and only in 1900, at the request of the Bavarian government, and most likely at his demand, he went to work at the University of Munich. He was honored by the world, as were hardly any scientists before him. His university awarded him an honorary doctorate, and the city of his birth, Lennep, declared him an honorary city citizen. Italy awarded him the Order of the Italian Crown, and the Royal Society of London awarded him the Rumford Medal, and despite all these honors, Röntgen continued to engage in scientific work.

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Very soon after the discovery, it became clear that X-rays are produced by moving electrons in matter, but until about 1907, Röntgen did not allow the word “electron” to be spoken at the Physics Institute of the University of Munich. Röntgen considered it an unproven hypothesis, often applied without sufficient grounds and need. He gave importance only to facts, not to their explanation. Röntgen donated the monetary part of the Nobel Prize to the University of Würzburg for research work. When the German government during the First World War turned to the population with a request to help the state with money and valuables, Röntgen gave all his savings. A.F. Ioffe, in his memoirs of Röntgen, wrote “In 1917, as a result of the blockade, famine reigned in Germany, and the entire population received meager food distributed on cards. Röntgen had many friends in Holland who sent him food parcels with butter and sugar. However, believing that with starvation no one should enjoy privileges, he gave all his parcels to the state for general distribution. In the last years of his life, he was forced to deny himself many things. Only once a week, he allowed himself a meat dish. To return to his favorite places in Switzerland, where he lived with his wife, who had recently died, he had to give up coffee, etc., for almost a whole year.” Röntgen died on February 10, 1923, from bowel cancer. According to his will, all his scientific materials and personal correspondence were destroyed.

2.6 X-ray Mania The enormous new possibilities offered by X-rays, especially in medicine, were understood almost immediately. However, here I would also like to note the unhealthy, manic shade of the reaction to the discovery, which provoked the appearance of X-ray mania. In various books and articles on the history of the discovery of X-rays, there are many anecdotal, humorous, and often ridiculous examples of the reaction of the public, amazed at the unexpected possibilities of the new discovery. A detailed description of the simplest equipment for generating X-rays, which appeared in the press, prompted hundreds of electricians, photographers, physicists, and doctors to create their own X-ray installations. Everything that could be photographed in Х-rays became the object of X-rays. Photos of feet in shoes, bones of hands with rings on fingers, and nut kernels in intact shells filled the pages of popular and technical magazines. Public lectures on new rays were given in all European capitals and relevant experiments were demonstrated. Röntgen became a celebrity in one week.

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In America, the famous inventor Edison, after reading the message about X-rays, immediately began experiments. He designed an X-ray fluoroscope that used calcium tungstate as a screen. These screens gave a better image than the barium platinum cyanide used by Röntgen. Edison immediately patented his discovery. Edison’s devices were exhibited at the “Electric Exhibition” of 1896 in New York. The first public demonstration of the new fluoroscope was a huge success. Many Americans were willing to stand in line to see their own skeletons. Once Edison announced the organization of a public demonstration of photographing the brain of a living person in X-rays—to capture how living thoughts flash through it. The hope of seeing how their brains “work” attracted many interested in the mysterious rays. In Paris, physicist Segui equipped a special office where anyone could get a photograph of his skeleton for money. There was a fear among the townsfolk that from now on, every passer-by could look through the walls into someone else’s apartment, and maybe even read other people’s thoughts. The owner of a hat shop in London placed an advertisement in the newspaper stating that he sells special hats made of a particularly dense material that is opaque to new rays. Anyone who wears such a hat can consider himself safe: no rays, visible and invisible, will detect a single thought in his head! The townsfolk believed that simple pocket X-ray machines could be developed that chaste people would have to defend themselves against. The guardians of morals frightened the townsfolk with the fact that special binoculars would soon appear, with the help of which sexual maniacs would examine people in the nude. In London, a firm lured ignorant women with X-ray-­ protective underwear. And in America, a newspaper reported that some young man in Iowa turned invisible beams on a piece of lead worth 13 cents; and what? Three hours later, the piece of lead turned into a piece of the purest gold, worth $153. Another paper claimed that New  York’s medical-surgical college had invented a new way to teach students anatomy: X-rays bounce off drawings in an anatomical atlas and then hit the student’s brain directly. The newspaper considered this teaching method more profitable and more convenient than the usual methods that have been practiced until now: since the drawings now seem to be firmly imprinted in the brain. A year after the discovery of X-rays, Parisian speculators were selling tickets for a special number: it was assumed that with the help of X-rays a ghost could be photographed. There were rumors that opera binoculars and lorgnettes would be supplemented with special devices for seeing in X-rays—this, they say, should

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Fig. 2.5  Shoe fluoroscope (~ 1930–1940). Figure from ORAU Museum of Radiation and Radioactivity Collection—https://www.orau.org/health-­physics-­museum/collection/shoe-­fitting-­fluoroscope/index.html. With permission of Dr. Pam Bonee

significantly increase the attractiveness of the evening hours spent at the opera by bored couples. On February 19, 1896, a member of the Somerset County Assembly in New Jersey introduced a special law prohibiting using X-rays in devices such as opera glasses and lorgnettes. The idea of such devices was played up in every possible way in newspaper drawings and cartoons. Non-medical use of X-ray radiation can also be an example of X-ray mania. Shortly after World War I, X-ray fluoroscopes to facilitate shoe fitting (Fig.  2.5) seem to have been independently constructed in the USA and UK. Soon the devices called ‘Foot-O-Scope’ in the USA and ‘Pedoscpoe’ in Europe became standard equipment in many shoe stores on both sides of the Atlantic. Exposure times were set by a timer and were typically 20 seconds but could be extended up to 45 seconds. The intensity of the radiation could take three levels: for men, women, and children. Despite the rather high doses, there were no reports of damage to the feet of buyers, which cannot be said about the sellers. There is even a case of the leg amputation of one of the saleswomen. Under pressure from policymakers, by the end of the 1970s, the use of shoe fluoroscopes had been completely discontinued. At the time of Röntgen, the townsfolk were only intimidated by the possibility of using special binoculars to examine people in the nude. A hundred years have passed and “undressing” X-ray scanners at airports have become a reality these days. True, now the demonstration of a naked body on display is replaced by a schematic image, but this is a matter of software settings. The use of X-ray scanners has met with ongoing resistance, but it is not the subject of this book. Another manifestation of X-ray mania is using the term “X-ray” to advertise products and goods that have nothing to do with radiation. Radioactivity, which will be discussed in detail in the next chapter, is a property inherent in the atom, i.e., a certain chemical element, more precisely,

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Fig. 2.6  Examples of using the indication “X-ray” on labels and advertising of goods, above—X-Ray headache pills, at the bottom—X-Ray whiskey. Figures from ORAU Museum of Radiation and Radioactivity—https://www.orau.org/health-­physics-­ museum/collection/brands/index.html. With permission of Dr. Pam Bonee

this property is inherent in the atomic nucleus. Therefore, objects, and products, in which such elements are present, can, in principle, be radioactive. X-ray radiation, in the form that we talk about in this chapter, is a property of the device, the X-ray tube. The device emits only when it is turned on. Therefore, no goods and products can have X-rays. The indication of the Х-ray nature of the goods is a publicity stunt. Radiologist and collector E.S. Gerson has assembled a collection of advertisements, labels, and real-life items with “X-ray” written on them. It is found on headache pills, golf balls, furniture polishes, razor blades, coffee grinders, whiskey bottles, and many other products. It was assumed that the inscription “X-ray” makes the product more attractive to the buyer. Approximately for the same reasons, at one time the labels “laser,” and later—“nano,” and “bio” were attributed to different products (Fig. 2.6). In the next chapter the reader will see that the word “radioactive” has been used similarly for a long time.

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Fig. 2.7  Bone Snapper X-Ray Rye Whiskey. Figure from the site of Backbone Bourbon Company—https://backbonebourbon.com/bone-­snapper-­xray-­4-­year-­reserve/ with permission of Nolan Smith – Owner.

Since the whiskey X-Ray advertisement shown in Fig.  2.6 more than 100 years have passed, but the appeal of the X-Rays name remains strong. The Backbone Bourbon Company launched a whiskey in 2011, also using the same symbol: Bone Snapper X-Ray Rye Whiskey (Fig.  2.7). The company puts several meanings into the use of this term. Still, perhaps the main one is clear from the name: just like X-rays, the new whiskey penetrates the bone. Please note that if at the beginning of the XX century, humankind was in a state of radio euphoria and the name X-Ray whiskey was supposed to increase interest in the product, now radiophobia is in the air, and the use of a reference to X-rays could scare the public, but no, apparently, whiskey is selling successfully, and this is a good sign.

3 Radio-Euphoria

3.1 Discovery of Radioactivity. Experiments of Henri Becquerel On January 20, 1896, at a meeting of the Paris Academy of Sciences, the famous mathematician Henri Poincaré read out Röntgen’s detailed letter on the discovery of new rays, showing the first photographs taken by X-rays. News of the new form of radiation has already spread widely and the story of the discovery has aroused great interest. Among the listeners was the forty-­ four-­year-old already venerable scientist Henri Becquerel. Back in 1886, he was elected a member of the Academy of Sciences, and in 1892, he headed the Department of Physics at the National Museum of Natural History. The same department was previously headed by his grandfather Antoine César Becquerel and then by his father Alexandre Edmond Becquerel. Becquerel was interested in the message about the place from which the X-rays came out. This was the place of the glass tube on which the cathode rays fell, and which glowed with visible light. The same place on the glass of the tube emitted both greenish-yellow rays visible to the eye and invisible X-rays. Becquerel suggested that the glow of the glass of an X-ray tube is precisely the real reason for the emission of X-rays. The fact is that the study of the luminescence of various substances was the main physical problem that Becquerel had been dealing with for many years. His grandfather and father dealt with the same problems. Henri Becquerel was particularly interested in phosphorescence, and Becquerel had a question: maybe in all cases, during the phosphorescence that Becquerel observed, invisible rays were also emitted, which no one had seen before, but Röntgen managed to see them. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2023 I. Obodovskiy, From Radio-phobia to Radio-euphoria, Springer Praxis Books, https://doi.org/10.1007/978-3-031-42645-2_3

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Recall that luminescence is a collective term that includes two types of luminescence of substances when excited by light of a different wavelength— fluorescence, and phosphorescence. Fluorescence is a radiation that quickly decays after the termination of excitation, so quickly that it was believed to be observed only during excitation. Phosphorescence is a long glow that continues after the cessation of excitation; in some cases, it can last for hours. The division of luminescence into fluorescence and phosphorescence is very conditional and currently has no scientific content. Typically, Becquerel excited phosphorescence with sunlight. He exposed the sample to the sun for some time, then transferred it to a dark room and studied the slowly fading glow, and now Becquerel took a photographic plate, carefully wrapped in opaque paper, put a phosphorescent substance on it, placed a metal object between the plate and the substance, the contour of which he hoped to see if, in addition to phosphorescence, X-rays actually arise that penetrate through thick opaque paper, and exposed it to the sun. For young readers, it should be clarified that before the advent of modern electronic photography, for almost hundred and fifty years, humankind used chemical photography. In the XX century, the glass plate coated with a photographic emulsion was replaced by a film. It had to be developed in a special solution—a developer and the resulting image was fixed in a fixer, then the plate was washed and dried. The Becquerel family amassed an extensive collection of phosphorescent substances, so there was a wide choice, but the hope of quickly attacking a suitable mineral is correspondingly small. But Becquerel was lucky, having gone through several phosphorescent substances, he obtained the desired result when using the double sulfate salt of uranium and potassium (potassium uranyl sulfate). This substance was beautifully phosphorescent, after a short exposure to sunlight, it began to emit a bright green glow. The same substance left a clear imprint on the photographic plate by some rays that passed through black paper, apparently the same as those discovered by Röntgen. On February 24, 1896, at a meeting at the Academy, Becquerel announced his success: the phosphorescence of uranium salt is accompanied by the emission of rays similar to X-rays. As was customary in science, it was necessary to check and double-check the results obtained, and Becquerel continued his research. The further description of events resembles a police report. On Wednesday and Thursday, February 26 and 27, Becquerel prepared several next piles—a plate wrapped in black paper with a cake of uranium salt on it—but the weather was cloudy these days, phosphorescence was almost not excited from weak scattered light, and Becquerel put these piles in the

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desk drawer to wait for sunny days and continue exploring. Historians of science have collected information about the length of daylight in Paris at the end of February 1896 and the state of the cloudiness in these days and confirm all this, almost legendary, information. On Sunday, March 1, it was also a cloudy day, and Becquerel decided to develop the plates. Historians of science have long debated why he did this. The scientist’s son, Jean Becquerel, explains his father’s actions by the scientific conscientiousness and thoroughness in conducting experiments inherent in all the scientists of the Becquerel family, by the desire to check that the plate is still suitable for work because Becquerel exposed it to the scattered daylight of a cloudy day. The well-known historian of science Lawrence Badash refers to the opinion of the American scientist G.E.M. Jauncey, who believed that Becquerel became impatient after waiting four days for bright sunlight. The famous Soviet scientist and brilliant popularizer of science, Matvey Bronstein, who had every reason to become a great scientist but did not have time to become one because he was shot in 1938 in the cellars of the Leningrad NKVD, in the book “Atoms and Electrons,” well understanding the motives that control the actions of the researcher, wrote: “out of boredom or nothing to do.” Those who believe in the predestination of all events on Earth see this as a manifestation of a higher power. But another version is possible. The fact is that back in 1861, one of the inventors of photography, Abel Niepce de Saint-Victor, announced that uranium salts emit some kind of radiation that is invisible to the human eye. The results of his work were published in several articles in the French journal Comptes Rendus of the Académie des Sciences. Whether Becquerel knew about Niépce’s results is not clear; historians of science suspect that he should have known. The fact is that Henri’s father, Edmond Becquerel published a book in 1868 where he cited Niepce de Saint Victor’s experiments with objects coated with uranium nitrate blackening photographic plates in the dark. So, it is unlikely for Henri not to be familiar with the Niepce’s work. Nevertheless, Becquerel does not mention Niepce in his Nobel lecture. If he knew about Niépce’s work, then developing the plate, which had lain in the dark, could be a completely conscious action, and not a random event. Then this explains the quick choice of uranium salt for experiments. This question is really interesting from a psychological point of view—to clarify how great discoveries are made and the personality traits of great scientists, but it is important for science that Becquerel developed a plate with a practically non-phosphorescent uranium mineral that had lain for four days (1896 was a leap year, February this year had 29 days) in a drawer, and saw on it a sharp imprint, much sharper than in previous experiments. Figure  3.1

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Fig. 3.1  The first evidence for radioactivity—images formed by Becquerel’s uranium salts. Figure from Henri Becquerel, Wikipedia—https://en.wikipedia.org/wiki/Henri_ Becquerel. Public domain

shows an image of Becquerel’s photographic plate which has been fogged by exposure to radiation from a uranium salt. The shadow of a metal Maltese Cross placed between the plate and the uranium salt meant that a metal plate partly absorbed radiation. However, note that the clarity of the shadow is much worse than the clarity in the case of X-rays. This is one of the important reasons why the public greeted the discovery of radioactivity at first with much less enthusiasm than the discovery of Röntgen. The very next day, March 2, 1986, Becquerel reported to the Academy of Sciences about a startling fact: exposure to sunlight is not required for the appearance of uranium rays. In subsequent work, Becquerel found that radiation comes from any substance containing uranium, phosphorescent and non-phosphorescent, the intensity of the radiation depends only on the amount of uranium. He also discovered that the radiation discharges the electroscope, i.e., makes air conductive. In modern terms, it ionizes air molecules. The discovery of Becquerel made a certain impression on scientists, but much weaker than the discovery of Röntgen. The new beams produced a much blurrier image than the X-rays and required noticeably longer exposures. In other words, they were of little use for translucence. In addition, if the physical laboratories of that time usually had high voltage sources, vacuum pumps, and many cathode tubes, and could easily reproduce the results of Röntgen, then preparations containing uranium were rare. After conducting some complex research, Becquerel decided that he had found out the basic

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properties of uranium rays and in 1898, switched to more exciting and more promising, from his point of view, work. In fact, the result obtained by Becquerel is striking. In Röntgen’s experiments, the energy of the electric current flowing in the cathode tube was converted into the energy of the rays, and the element uranium, without any supply of additional energy or excitation, radiates energy, continuously, without any noticeable weakening. Seemingly unshakable ideas about energy conservation collapsed, and the shadow of a seemingly forever buried “perpetual mobile” loomed.

3.2 Discovery of Radium: Works of Pierre and Mari Curie The young Polish woman Maria Sklodowska, who had just graduated from the Sorbonne, became interested in Becquerel’s messages. She was looking for a topic for her dissertation and a new, unknown phenomenon seemed worthy to her to take up her research. She recently married the well-known French physicist Pierre Curie, so her legal name is Madame Skłodowska-Curie, but she is generally referred to in the literature as Madame Curie or simply Marie. A 1900 photograph of Pierre and Marie Curie in their laboratory is shown in Fig. 3.2. In those days, almost no one knew how to detect new radiation. There were no Geiger counters at that time; the first version of such a counter appeared only in 1908. It was difficult and troublesome to work with photographic plates; they had to be developed, fixed, dried, and then blackening was measured. Using the property of uranium rays discovered by Becquerel to produce gas ionization, Marie began to use a special electroscope designed for her work by Pierre and his brother Jacques to detect radiation. After several weeks of work, she found that the radiation intensity is available for accurate quantitative measurements. Before her work, the research was purely qualitative: radiates—does not radiate. Marie checked that the radiation intensity is proportional to the amount of uranium in the samples under study, that it is not affected by the state of the chemical compounds of uranium nor by external influences such as the degree of illumination or temperature. Next, Marie tried to find out if there were other elements with the same property. To do this, Marie studied all the elements known then, both in pure form and compounds. As a result, she discovered that there is another

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Fig. 3.2  Pierre and Marie Curie in their laboratory. The photo of 1900. Figure from Marie Curie, Wikipedia—https://en.wikipedia.org/wiki/Marie_Curie. Public domain

substance that emits rays similar to those of uranium. This substance turned out to be thorium, and in this case, Marie showed that the radiation of thorium is also an atomic property of the element. Once another element appeared with the same property, finding the correct term to define the new property of matter, manifested by the elements uranium and thorium was necessary. Marie proposed the name “radioactivity” for this phenomenon, which has become generally accepted. Marie Curie tested for radioactivity not only simple compounds, salts, and acids, but also many minerals. Minerals containing uranium or thorium turned out to be radioactive, but some of them turned out to be much more active than could be expected, judging by the content of uranium or thorium. This anomaly surprised Marie very much and even, as historians of science write, put both her and Pierre at a standstill for some time. After discussing all the known facts, the couple suggested that the minerals contain a small amount of some new substance, much more radioactive than uranium or thorium. This substance could not be any of the elements already known, since the elemental composition of minerals has been studied in detail. Therefore, it must be a new chemical element. Vividly interested in this issue, Pierre Curie left his work on crystals, temporarily, as he thought, and joined his wife in this task—the extraction of a

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new radioactive substance from those minerals that turned out to be more active than uranium itself. Since that time, the couple have worked together. For research, of all the minerals, the Curies chose uranium ore from Joachimsthal, called petchblende or uraninite. This uranium mineral, in its pure form, was found to be almost four times more radioactive than uranium oxide. Since the new suspected radioactive element did not appear in the most accurate chemical analyses, it was clear that much ore would be needed. It was also clear that expensive uranium ore itself was unnecessary; it was enough to get what is called a dump, i.e., remnants of ore from which uranium has already been isolated. It was in these remains, according to Curie, that the mysterious new substance was located. Since the beginning of the XVI century, in the area of the modern city of Jachymov, in the Czech Republic, on the southern spurs of the Sudetenland, various minerals were mined. The city of Yakhimov was formerly called Joachimsthal (Joachimsthal), the valley (thal—in German) of St. Joachim, the father of the mother of Christ Mary and, therefore, the grandfather of Christ. In the XV-XVI centuries, the city was part of Austria-Hungary, and at the end of the XIX century—Germany. At various times, silver, lead, zinc, tin, cobalt, and later uranium were mined in the mines. From the silver mined in the mines of Joachisthal, the owner of this area, Count von Schlick, minted coins called “Joachimstalers” or simply “thalers.” Soon the name “thalers” became “daler” and then “dollar.” In 1792, the newly independent United States of America adopted this coin under the name “dollar” as the main currency. By the end of the XIX century, the silver of Joachimsthal was long and completely worked out, and uranium was mined from Joachimsthal ore. Uranium compounds are used to make glass and porcelain glazes. A detailed story of how the Curies got ore for processing would take us too far aside. Suffice it to say that the Austrian government, to which the Joachimsthal uranium mines were subordinated, presented the Curie spouses with a ton of uranium petch blende slag for free. Recipients only had to pay for shipping. Another ten tons were paid by the famous banker Baron Edmond Rothschild. A dirty brown mass mixed with pine needles was brought and dumped into the shed. All Curie’s work had to be carried out in a room that they managed to get with great difficulty. It was a small workshop overlooking the yard and an abandoned wooden shed on the other side of the yard with a leaking glass roof. Once, this barn was the dissecting room of the medical faculty, but for a long time, it was considered unsuitable even for storing corpses.

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The work consisted in carrying out known chemical reactions and measuring the radioactivity of the products, separating the reaction product into which the activity had passed, and carrying out new reactions again. Through successive selection, scientists hoped to gradually isolate that part of the mineral into which the desired radioactive substance passes. The work was tremendous; it was necessary to process eleven tons of ore, transfer vats and tanks, evaporate and pour solutions. Marie spent whole days stirring boiling liquids with a huge stick. Both physicists did all the work manually using the most primitive means. They worked, according to eyewitnesses, rather like laborers. Many years later, M.  Curie admitted that she was not sure whether she would have shown the same perseverance if she knew how little radium is contained in the ore and what titanic work would have to be done to obtain at least a meager amount of it. Very soon, Pierre and Marie discovered that there was not one, but two unknown radioactive substances in the material they were studying, close in their chemical properties to bismuth and barium. Ordinary bismuth and barium are completely non-radioactive, which means that the radioactivity of these elements when isolated from tar ore was actually due to the presence of two new elements in them in an insignificant amount. One of them, close in chemical properties to bismuth and accompanying it in all reactions, was the first to be discovered, and Marie named it “polonium” after her homeland. The discovery of this element by the Curies was reported in July 1898, and on December 26, 1898, they already reported on another element, the chemical analog of barium, which they called “radium.” It was not the element itself, but a drug with an activity 900 times greater than the same amount of pure uranium. But the existence of new elements was obvious to the Curies, perhaps to some other physicists, but for chemists, information about radiation, a new phenomenon for them, does not mean anything. Nobody knows either the atomic weight of the new elements or their chemical properties, and chemists, true to their principles, conclude “No atomic weight—no element. Show a new element, and we will believe.” And the Curies take on the next stage of work to obtain the simplest chemical compound of radium—radium chloride. It took them almost four years, from 1898 to 1902, of truly heroic work under the conditions described above. In 1902, four years after starting work, Pierre and Marie Curie obtained the first few tenths of a gram of pure radium chloride. This resulted from a titanic four-year work on processing a huge pile of Joachimsthal slag, but this radium chloride was a million times more active than the same amount of

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pure uranium. Later, in 1910, Marie Curie obtained pure radium by electrolysis of chloride salt. The tremendously complex problem of isolating radium from ore has become widely known and has served as a symbol and model for a complex problem repeatedly used in various literary works and in public opinion. It is necessary to note another amazing result obtained by Curies during their work on the isolation of radium. In the very first experiments on preparations of radium, it was noticed that a substance containing radium is always a little warmer than all the surrounding objects. Pierre Curie made measurements with a calorimeter and found that the thermal energy released by 1 g of radium is ~590 J/h in modern units (~140 cal/h). This result excited everyone, for even the idea of the existence of any substance whose temperature is higher than the temperature of the surrounding air was unbearable for old-fashioned physicists. All sorts of ways were devised to get around the problem of obtaining energy from “nowhere,” for example, the notion that radium had a peculiar property of pumping heat out of the air was discussed. Elementary calculations show that one gram of radium, for no apparent reason, can heat 200 grams of water to a temperature of 100 °C in 6 days. This energy released by a gram of radium is not very large: as much as 50 hours must pass for a gram of radium to give off as much energy as one gram of coal gives off when burned, but on the other hand, a gram of coal, having burned down, ceases to be coal and gives off energy. A gram of radium, having given up, albeit very slowly, over 50 hours, the same number of calories, remains the same as it was and continues to emit energy to those at the same rate. Now we can say that the amount of heat released by a gram of radium is 250 thousand times greater than when the same portion of coal is burned. It was this ability of radium to emit, albeit very slowly, large and seemingly completely unlimited amounts of energy that should have interested physicists most of all: it made it possible to talk about the riddle of radium, about the riddle of radioactivity, the painful riddle that made the physicists of 1900 rack their brains over the mysterious properties of radium and its rays. We have already noted the constant release of energy by uranium in the section on the discovery of Becquerel. Still, there this energy was relatively small, while radium continuously emits energy a million times greater. Another no less strange fact discovered when working with radioactive substances is their complete independence from external influences. Physicists repeatedly tried to influence radioactivity by raising or lowering the temperature, using the highest pressures or magnetic fields available at the time, but the activity of the substance did not change in any way.

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3.3 Theory of Radioactivity: Works of Rutherford and Soddy After the discovery of uranium rays by Becquerel, and especially after the discovery of radium by the Curies, other scientists joined the research of radioactivity, the most important, one might say, key results were obtained by two young researchers Ernest Rutherford and Frederick Soddy (Fig. 3.3). E. Rutherford, a young New Zealander, in 1895 received a grant to travel to Europe for postgraduate studies at the Cavendish Laboratory of Cambridge University, where his supervisor was already famous at that time J.J. Thomson. Many physicists at that time turned their attention to the newly discovered X-rays, including Thomson. He studied the effect of X-rays on electrical discharges in gases and attracted Rutherford to this work, and when the Curies announced the discovery of radium, Rutherford became interested in the issue of radioactivity. In 1898, Rutherford discovered that there are two kinds of rays in the composition of uranium radiation, which he called alpha and beta rays. He found that alpha rays have many times greater ionizing power and many times less penetrating power than beta rays.

Ernest Rutherford

Frederick Soddy

Fig. 3.3  The creators of the radioactive decay theory. (a) Rutherford. Figure from Ernest Rutherford, Wikipedia—https://en.wikipedia.org/wiki/Ernest_Rutherford. Public domain. (b) Soddy. Figure from Frederick Soddy, Wikipedia—https://en.wikipedia.org/ wiki/Frederick_Soddy. Public domain

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When, in 1900, the French physicist Paul Villars discovered even more penetrating radiation as part of radium radiation, Rutherford suggested calling it gamma rays. These names, alpha-, beta- and gamma-radiation, have stuck and are used to this day. On Thomson’s recommendation, in 1898 Rutherford took up a professorship at McGill University, in Montreal, Canada. There he received at his disposal an excellent, well-equipped laboratory and took up the study of the radioactive properties of uranium and thorium. A young electrical engineer at McGill University, R.B. Owens had previously discovered some new phenomenon, something that was not alpha- or beta-rays, which was emitted by thorium and had an amazing property that distinguishes it from all already known rays: it was subject to the movement of air and flew away if blown on it. Owens suggested that Rutherford switch to the study of a new phenomenon, and Rutherford, with his inherent intuition, sensed new opportunities in this phenomenon and enthusiastically set about studying it. Rutherford called the new radiation emitted by thorium the “emanation” of thorium. At the end of the summer of 1900, Rutherford went home to New Zealand, where his bride awaited him. After Rutherford’s return in the autumn of 1900 with his young wife, he was introduced to the 23-year-old chemist from Oxford, Frederick Soddy, who had just been appointed demonstrator in chemistry. Early in 1901 Soddy left his studies in the chemistry department and joined Rutherford in his attack on the problem of emanation and other products of thorium. The joint work of Rutherford and Soddy proved to be extremely fruitful. In a relatively short period of time, they found out that emanation has a material character, that it is a gas. Somewhat later they will prove that it is a gas from the group of inert gases. They saw that the emanation loses its radioactive properties over time. This allowed them to conclude that if the emanation loses its radioactive properties over time, then probably the same can be said about all other radioactive substances, and since the decrease in the radioactivity of radium and uranium does not manifest itself even for several years, it means that a noticeable decrease in their radioactivity occurs very slowly. It certainly occurs, but over times many times greater than the reasonable duration of any experiment. Based on the work carried out, Rutherford and Soddy formulated the theory of radioactivity. According to this theory, a part of an atom flies out of it, and this loss turns an atom of one chemical element into an atom of another. Now it is difficult to imagine the audacity of the theory that Rutherford and Soddy came up with. With their theory, they encroached on the

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fundamental provisions of the science of that time. For a hundred years, the best scientific minds of Europe have struggled with the attempts of alchemists to carry out the transformation of elements, to turn one element into another, it would be nice into gold. As a result of hard work throughout the XIX century, and not just work, but also the struggle with adherents of alchemy, the indivisibility, and immutability of elements was proved, the idea of the existence and immortality of atoms triumphed, that atoms live forever, do not change, do not age, are not destroyed. Recall that the word “atom” in translation from ancient Greek means indivisible. And suddenly there are young people, almost boys, who claim the exact opposite. It is clear that their ideas met with noticeable resistance. Moreover, if they were not really prevented from working, then it was more difficult to report and publish their ideas. The administration of McGill University was worried about the reputation of the university, they were afraid that the radical views promoted by young scientists about the instability of material atoms could cast a shadow on the university. The theory of radioactivity dispelled many seemingly unshakable prejudices. The prejudice about the indivisibility of the atom was destroyed thanks to the discovery of the electron, which showed that the atom is a complex system and that smaller particles can fly out of it. Research on radioactivity destroyed the prejudice about the immutability and immortality of atoms. An atom of a radioactive substance lives for some time and then dies, throwing out a particle, which is also an atom of some substance, and small splashes in the form of beta particles and gamma rays. In radioactive phenomena, the transformation of some chemical elements into others occurs, and the birth and death of atoms occur. Now we know that the paradox of energy release “out of nowhere” in this theory is solved simply, energy is released during the transformation of atoms into other lighter atoms, and atoms spend themselves on energy release. The creators of the law of radioactive decay could not have known this. The decay theory was formulated in 1901–1903, and Einstein’s famous formula, showing the relationship between mass and energy, appeared only in 1905. The authors attributed the colossal energy released during radioactive decay to some intra-atomic processes. It was precisely intra-atomic, and not intra-­ nuclear, that the understanding that an atom has a nucleus and that decay processes occur in the nucleus came ten years later. The nuclear model of the atom was formulated by Rutherford (Fig. 3.4). Despite the resistance, the new ideas eventually won out relatively easily and were accepted by the scientific community, because the works of scientists

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Fig. 3.4  The decay of a uranium-238 nucleus into a thorium-234 nucleus and an alpha particle. The sum of the masses of the thorium nucleus and the alpha particle is less than the mass of the uranium nucleus. The mass difference is converted into the kinetic energy of the alpha particle and the nucleus. The figure shows that the nucleus consists of protons and neutrons. At the time of the work of Rutherford and Soddy, this was not yet known; the proton-neutron model of the nucleus appeared only in 1932. More so, at the time of radioactive elements transmutation discoveries, it was not known that there is a nucleus inside an atom

involved in the creation of the theory of radioactivity were very reliable and convincingly proved all the basic provisions. In 1907 Rutherford returned to England and continued his studies at the University of Manchester. He became one of the greatest physicists of the twentieth century, in 1908 he received the Nobel Prize in Chemistry (a circumstance that surprised him very much, he considered himself a physicist), and in 1919 he headed one of the most respected scientific laboratories in the world—the Cavendish Laboratory of the Cambridge University, becoming the successor of J.J. Thomson. Rutherford discovered the atomic nucleus, carried out the artificial transmutation of elements, and did many other very important works, but the story of this is beyond the scope of this book. Rutherford and Soddy laid the foundations of ideas about the transformation of atoms, and then, by their works, as well as by the works of many other scientists, it was shown that in this case there is a whole chain of decays that forms radioactive chains, or, as they are otherwise called, radioactive families. At the beginning of the chain is the first parent element, which is radioactive, followed by other radioactive elements, and at the end—the last stable element. An example of the deciphered uranium-238 decay chain is shown in Fig. 3.5. There are 14 radioactive members in the uranium-238 chain, excluding low-probability decay modes, and 11  in the thorium chain. The main difficulty in deciphering these chains was the difficulty of chemically

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Fig. 3.5  Modern view of the decay chain of uranium-238. The parent element uranium-­238 is in the upper right corner, the last in the chain, the stable isotope of lead-206, is in the lower left corner. Unlikely, decays are not shown

identifying the radioactive members of the chain due to the extremely low concentration of these elements. In addition, there was still no concept of isotopes—atoms with the same atomic number, but with different masses. Many members of the chains arising from the radioactive decay of uranium, and then radium, before their chemical identification was performed, received the names of the type: uranium I, uranium II, radium A, radium B, radium C, etc. Although it is now known that they are isotopes of other chemical elements, their historical names are traditionally sometimes used, for example, polonium-218 is radium A, bismuth-214 is radium C, polonium-210 is radium F, etc. Now, knowing what experimental possibilities scientists had at the time of deciphering radioactive families, it is difficult to imagine how they figured it all out. Brilliant (and hardworking) people were.

3.4 Honoring the Pioneers of the Study of Radioactivity Information about the discovery of radioactivity in the first place, of course, had an effect on the scientific world. The discoverers quickly became famous. In June 1903, Pierre and Marie Curie were invited to London to the famous Royal Institute to give a talk on radium. In the evening, at the meeting

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dedicated to Pierre’s report, next to Marie, the first woman presented at the meetings of the Royal Institution, sat the great scientist, Lord Kelvin, after whom the unit of absolute temperature is named, the whole scientific England was in the hall. I quote Eve Curie further: “The admiration that prevailed this evening was also reflected the next day. All London wished to see the “parents” of radium. The professor and Madame Curie are invited to dinners, to banquets. Pierre and Marie attend brilliant receptions and listen to toasts, recited in their honor… Marie feels uncomfortable under the gaze of many eyes directed at her, such a rare creature, at such a phenomenon as a woman physicist. In November 1903, the Royal Society in London notified Monsieur and Madame Curie by letter that, as a token of their respect, it awarded them one of the highest awards—the Davy Medal. No less honors went to Rutherford. In 1903, 32-year-old Rutherford was elected a member of the London Society, and in November 1904, the society awarded him the Rumford Medal. According to the definition of one of the English physicists, it was “the preliminary rumble of a whole avalanche of further honors.” The famous Irish physicist J. Larmor, shortly before being elected secretary of the Royal Society, wrote to Rutherford on April 3, 1903: “I am glad to know that you are coming in May. You will be the season’s hero because the newspapers have suddenly become radioactive.” Another colleague wrote to Rutherford that “scientific London is at his feet.” In 1903, Rutherford made a trip to Europe. In Paris, Rutherford visited Pierre and Marie Curie on the same day that Marie was defending her doctoral thesis, on June 25, 1903. In the evening of the same day, prof. P. Langevin invited Rutherford and his wife, together with the Curies and the French physicist J.  Perrin, to dinner. The guests were sitting in the garden, it was about 11 pm when Professor Curie brought out a pipe, part of which was coated with zinc sulfide. The tube contained a concentrated solution of radium salt. In the darkness of the night, its glow was amazingly bright. Returning from a European trip, Rutherford found a changed atmosphere in Canada. He was already famous. Radium became a subject of general fascination, and the theory of radioactivity aroused the greatest interest. Journalists besieged the physics laboratory, publishing fantastic articles in the press and inventing fables, until they were denied access to the sacred abode.

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3.5 Radio-Euphoria Ideas about the wonderful properties of radiation were transferred to their healing capabilities, which prompted manufacturers to produce various consumer products containing radium, uranium, thorium, and radon. A large number of products containing radioactive substances appeared on the mass market. The production of goods with radioactive components began around 1905, and some of them have survived to this day. The museum of the Oak Ridge Association of Universities, the Curie Museum in Paris, the National Museum of Nuclear Science & History in Albuquerque, the Lucy Jane Santos Museum of Radium, and several others display a large number of radioactive mass-use goods. Adding the word “radioactive” to product descriptions and advertisements was supposed to increase their appeal and sales greatly. We already wrote about the same situation with the word “X-ray” in Chap. 2. In our time, to tempt buyers, words like “nano-,” “eco-,” “bio-,” and others are introduced into advertising. One of the most famous radioactive cosmetics companies, Tho-Radia, was founded in France in 1933 by pharmacist Alexis Moussali. Dr. Alfred Curie was invited to the company, mainly due to his surname, although in fact, he had nothing to do with the famous scientists Pierre and Marie Curie. The range of Tho-Radia products included soap, cleansing milk, toothpaste, day and night creams, skin tonics, beauty powder, rouge, lipstick, and many other cosmetics. The firm’s products contained thorium chloride and radium bromide, both radioactive. Many goods were marked with a picture, which shows a pretty young blond woman illuminated by an orange glowing light coming upwards from Tho-Radia preparations containing radium, and each buyer could guess that the source of this light is radium. We reproduce the famous Tho-Radia advertising picture (Fig. 3.6). The same head was also present on large advertising posters of various beauty products containing radium and thorium from the collection of the Curie Museum in Paris. Tho-Radia cosmetics were sold not only in France but were certainly available as far afield as Belgium, Italy, Portugal, Romania, and Egypt. The gradual phase-out of radioactive substances from consumer products, caused, in particular, by the most high-profile cases—the case of the radium girls (Sect. 4.4), the Eben Byers case (Sect. 4.3), and some other less high-­ profile ones, led to the fact that by 1937 the French government had placed significant restrictions on the sale of products that contained radioactive

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Fig. 3.6  Tho-Radia’s most iconic promotional image. Figure from the collection of the Oak Ridge Museum of Radiation and Radioactivity—https://www.orau.org/health-­ physics-­museum/collection/radioactive-­quack-­cures/pills-­potions-­and-­other-­miscellany/ tho-­radia-­items.html. With the kind permission of Dr. Pam Bonee

substances. According to some reports, the company functioned with varying success until 1962. Tho-Radia was not the only company to use radioactive substances in cosmetics. In Fig. 3.7 one can see a flyer from the London firm Radior. On the website of the Oak Ridge Museum of Radiation and Radioactivity (Oak Ridge Associated Universities—ORAU), one can see tubes of radioactive toothpaste Doramad (Fig. 3.8). It was produced by the large chemical concern Auer (Auergesellschaft) in Berlin, Germany, from the 1920s through World War II. The story of how the production of radioactive toothpaste is connected to the German nuclear weapons program is told in the book Alsos, written by the Nobel Laureate, Science Director of the Alsos Mission, Samuel Goudsmit. As you know, the goal of the Alsos mission was to collect information about the German nuclear energy project. After that, the USA from the west, and the USSR from the east, sucked out of Germany practically everything that had to do with the atomic nucleus and radioactivity. So, there are no radioactive preparations left even for toothpaste.

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Fig. 3.7  Advertisement for Radior’s full range of beauty products for women. Figure from File:Radior cosmetics containing radium 1918.jpg—https://commons.wikimedia. org/wiki/File:Radior_cosmetics_containing_radium_1918.jpg. Public domain

Another German radioactive product, a box for radium pastilles, is shown in Fig. 3.9. The text on the box in German indicates that that pastilles were produced under the auspices of the City of Heidelberg using the radioactive water from a thermal spring. A metal plate the size of a plastic payment card, coated on one side with a layer of uranium ore, was supposed to reduce the content of nicotine, tar, and harmful gas emissions in tobacco without affecting its taste (Fig. 3.10). The plate is named NAC (Nicotine Alkaloid Control) plate. Such plates were

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Fig. 3.8  Doramad—Radioactive Toothpaste (Radioaktive Zahncreme—in Deutsch). Figure from the collection of the Oak Ridge Museum of Radiation and Radioactivity— https://www.orau.org/health-­physics-­museum/collection/radioactive-­quack-­cures/pills-­ potions-­and-­other-­miscellany/doramad-­radioactive-­toothpaste.html. With the kind permission of Dr. Pam Bonee

Fig. 3.9  Radium Pastille Container from Germany, circa 1920. Figure from the collection of the Oak Ridge Museum of Radiation and Radioactivity—https://www.orau.org/ health-­physics-­museum/collection/radioactive-­quack-­cures/pills-­potions-­and-­other-­ miscellany/radium-­pastille-­containers-­from-­germany.html. With the kind permission of Dr. Pam Bonee

produced in Japan. The firm Koei Bussan Co., Ltd. of Japan in 1983 tried to receive permission to market the plate in the US. According to Paul Frame (ORAU Museum) this was never done. In the propaganda of radioactive goods, the topic of the positive effect of radiation on sexual life is actively discussed. Thus, in the advertisement of radium water “Radithor” (Sect. 3.6), it is indicated that it clearly manifests itself as a sexual stimulant, increases the sexual power of men, weakens the frigidity of women, and much more. Individual products of the same direction appeared on sale. To increase the sexual power of men, “Vita radium

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Fig. 3.10  A metal plate coated on one side with a layer of uranium ore for reducing the content of nicotine, tar, and harmful gas emissions in tobacco (ca 1990). Figure from the collection of the Oak Ridge Museum of Radiation and Radioactivity—https:// www.orau.org/health-­p hysics-­m useum/collection/radioactive-­q uack-­c ures/pills-­ potions-­and-­other-­miscellany/nac-­plate.html. With the kind permission of Dr. Pam Bonee

suppositories” were offered (Fig.  3.11). Paul Frame on the site of ORAU Museum cites an advertisement of radium suppositories: “The man who has lost normal manly vigor, these precious attributes of youth, knows how to appreciate their value. He realizes that happiness depends on his ability to perform the duties of a REAL MAN. Sweet, glorious pleasures of life. Nature intended that you should enjoy them.” One more product should be added to the radium sexual power amplifiers—a box of radium condoms (Fig. 3.12) produced by the Nutex Company of Philadelphia in the USA in the 1940s. The trademark name Nutex had been in use since at least 1927. About this product, one of the readers joked: “Once upon a time, we used radium condoms for glow-in-the-dark sex.” In fact, this product does not contain a single microgram of radium. In this case, the reference to radium is a pure publicity stunt. By the way, the ORAU Museum website shows another box, as Paul Frame assures—empty, with X-ray condoms. Restrictions or even a ban on the use of radioactive substances in products of mass use began even during the period of radio-euphoria experienced by the population. A sharp change in mood occurred after the Second World

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Fig. 3.11  Anal suppositories for increasing the sexual power of men (ca 1930). Figure from the collection of the Oak Ridge Museum of Radiation and Radioactivity—https:// www.orau.org/health-­p hysics-­m useum/collection/radioactive-­q uack-­c ures/pills-­ potions-­and-­other-­miscellany/vita-­radium-­suppositories.html. With permission of Dr. Pam Bonee

Fig. 3.12  Radium condoms. Figure from the collection of the Oak Ridge Museum of Radiation and Radioactivity—https://www.orau.org/health-­physics-­museum/collection/ brands/nutex-­radium-­condoms.html. With the kind permission of Dr. Pam Bonee

War, the nuclear bombing of Japanese cities, and especially after the 1952 episode with the Japanese boat Fukuryu Maru, which fell under radioactive fallout from the Bravo thermonuclear explosion on Bikini Atoll (Sect. 4.7). However, even after that, goods with radioactive content continued to be sold.

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Let’s take for example “anti-nicotine plates” (Fig. 3.10) that were produced until 1990, and “radon pillows” (Fig. 3.13), it is known that they were on sale at least as far back as 2004. Moreover, the “Radioactive Quack Cures” section of the ORAU Museum website has a subsection “Twenty-first Century Products.” Just now it contains a list of only 12 products, all of them from Japan. Descriptions of almost all products contain information about the radioactivity of this product. For example, “The Health Card is a laminated paper card manufactured by the Wellrich Company, Ltd. of Osaka Japan. It is intended to be carried in a purse, wallet or pocket. Approximately 1,000 counts per minute (cpm) above background as measured with a pancake GM probe.” To clarify what 1000 cpm means, note that the typical background count rate at sea level is often about 20 to 100  cpm, depending on location and detector configuration. Here we are talking about goods, the radioactivity of which was especially emphasized as a property that enhances the dignity of the goods, and do not pay attention to goods in which increased radioactivity was discovered by accident, and there are those too. Among the goods with radioactive components, goods are made in the USA, Germany, France, and Russia. Some of the radioactive products

Fig. 3.13  Radon pillow (1990s). Figure from the collection of the Oak Ridge Museum of Radiation and Radioactivity—https://www.orau.org/health-­physics-­museum/collection/radioactive-­quack-­cures/radioactive-­pads/radon-­pillow.html. With the kind permission of Dr. Pam Bonee

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produced created a really serious background, but many of them, due to the fraud of the manufacturers, were essentially a dummy—a placebo. In conclusion, we note that a very important role in radio-euphoria was played by the radioactive gas Radon. Chapter 9 is devoted to Radon, its role in creating a mood of euphoria, its real impact on health.

3.6 Radium Water “Radithor” One manifestation of the radio euphoria that gripped large parts of the population soon after discovering X-rays and radioactivity was the most famous radioactive product, radium water “Radithor”. In 1910–1920s based on general ideas about the effect of small doses of newly discovered ionizing radiation on cells, tissues, organs, and the whole organism, a direction in medicine called mild radium therapy appeared. This distinguished it from the effects of high doses, which were already used at that time to treat various diseases, particularly cancer. The effects of radium were compared with the very popular at the time homeopathy: in large quantities, it was destructive, while in small quantities it was beneficial. Roger Macklis, the chairman of the Department of radiation oncology at the Cleveland Clinic Foundation, in a 1990 article describing the Eben Byers case, reinforces the role of low doses of radium: “Perhaps they were even necessary.” Among the many companies, producing radioactive drugs, and doctors using them in their practice, a certain William Bailey opened in 1925 in East Orange, New Jersey a company called Bailey Radium Laboratories, which produced radioactive water called “Radithor.” According to Macklis, despite advertising showing the extraction, purification, and testing of radium at Bailey Labs, “Bailey simply bought his radium and mesothorium (radium 228) from the nearby American Radium Laboratory of New Jersey, bottling it in distilled water at his plant and marking up the price more than 400%.” (500% in the other text). Radithor was bottled in about half an ounce (16.5 ml) and sold in packs of 30 bottles for consumption one bottle a day. A pack of 30 bottles to use for a month costs $30, a dollar a bottle. In today’s prices, that’s ~$18 per bottle, $540 per pack. Quite an expensive treat, only the wealthy could afford it. The firm claimed that each bottle contained about 2 microcuries of radium, 74 kilobecquerels in modern units. One of the bottles is shown in Fig. 3.14. Advertisements for Radithor reported its near-universal healing ability. The Bailey Radium Laboratory described it as a cure for dyspepsia, high blood pressure, impotence, and more than 150 other “endocrinologic” maladies.

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Fig. 3.14  A bottle of Radithor (radioactive water). Figure from the collection of Oak Ridge Museum of Radiation and Radioactivity—https://www.orau.org/health-­physics-­ museum/collection/radioactive-­quack-­cures/pills-­potions-­and-­other-­miscellany/radithor.html. With the kind permission of Dr. Pam Bonee

The booklet issued by the firm especially drew attention to its powers as a sexual stimulant and aphrodisiac, noting that, “Radium water has long been known as a powerful aphrodisiac. This is no doubt due to the stimulation of the adrenals, thyroid, and pituitary, as well as the gonads. By this method of treatment, unusual success has attended the treatment of sexual weakness, impotency, frigidity, decreased libido, and other sex aberrations.” During the existence of the company, approximately 400,000 bottles of Radithor were sold. The sale of Radithor allowed William Bailey to become rich, and Radithor itself became famous, but not at all because of its healing properties, which it apparently really had, but rather because of its role in the emergence and spread of radiophobia, but more about this in Sect. 4.3 “The case of Eben Bayers.”

4 From Radio-Euphoria to Radio-Phobia

The previous chapters showed what fantastic prospects humankind expected after learning about the discovery of new rays, with what enthusiasm discoveries were met, and how the moods in society called X-ray mania and radio-­ euphoria arose. Now it’s time to figure out why and how these moods changed sign, changed to fears and, in extreme manifestations, to horrors, to what is now called radio-phobia.

4.1 Radiation Exposure Before the Discovery of Radiation We now know that people were exposed to radiation even before radiation was discovered. From the very appearance of the first signs of life on planet Earth, all living organisms have been in the field of ionizing radiation. Radiation likely played a significant role in the origin of life. Even more likely, without radiation, the development of living organisms and the speciation processes would have been much slower and poorer. Appeared humanity was exposed to radiation, not suspecting it. In particular, people have encountered the beneficial effects of radiation on health without understanding the valid reason for such an effect. The therapeutic effect of radon baths was known long before the discovery of radioactivity. Radiation also showed its malicious, dangerous character. In cases where the radiation intensity significantly exceeded the usual natural radiation background, people got sick and died, unaware of the true causes of the trouble.

© The Author(s), under exclusive license to Springer Nature Switzerland AG 2023 I. Obodovskiy, From Radio-phobia to Radio-euphoria, Springer Praxis Books, https://doi.org/10.1007/978-3-031-42645-2_4

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In some mines in Central Europe, various minerals have been mined since the beginning of the XVI century. In the context of the book, two regions in the Ore Mountains are of particular interest—the Schneeberg region in Saxony, Germany, on the northern spurs of the Ore Mountains, and the Jáchymov region, in the Czech Republic, on the southern spurs of the Sudetenland. The Jachymov area is the former Joachimsthal, where the Curies got their uranium waste to isolate radium. In both areas, the miners were seriously ill and died quickly. The phenomenon was so severe and widely known that their disease received a special name, “miners’ disease” or “Schneeberg lung disease.” A variety of symptoms of the disease had a common feature—a disease of the pulmonary tract. In retrospect, it is clear that Schneeberg’s disease combined silicosis, tuberculosis, and lung cancer, but the superstitious local population attributed the disease to the devil’s influence. In the same areas, houses were built from stone with a high uranium content in the XV-XVII centuries. The average life expectancy in such houses was 35–40 years. Workers of factories where paints based on uranium compounds were made for painting on porcelain, ceramic glazes, and enamels, also fell ill. The disease of the miners was noticed by the doctor Philippus Aureolus Theophrastus Bombastus von Hohenheim, who worked in the area in the thirties of the XVI century, known as Paracelsus and one of the founders of mineralogy, who also dealt with medicine, meteorology, philosophy, history, Georg Bauer, known under the name Agricola. Both researchers were able to debunk the idea of the devil and linked the disease to the ore mined in the mines. Paracelsus named the disease “mala metallorum.” Agricola turned his attention to the ventilation of the mines and found that this significantly reduced the incidence, as described in his book De Re Metallica. Now we can say that Agricola guessed the release of natural radon from rocks. Ancient engravings with portraits of Agricola and Paracelsus are shown in Fig. 4.1. In 1879, two German researchers, Hartung and Hesse, showed that most of the miners died due to malignant tumors of the lungs. Later, radon was discovered, its release from rocks, and miners’ disease was associated with exposure to ionizing radiation from radioactive radon gas and short-lived decay products of its decay that accumulate in the air of poorly ventilated mines.

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Fig. 4.1  Georg Bauer (Agricola), fictive 1927 portrait—left, Philippus Aureolus Theophrastus Bombastus von Hohenheim (Paracelsus), the Louvre copy of the lost portrait by Quentin Matsys—right. (a) Agricola—Figure from Georgius Agricola, Wikipedia—https://en.wikipedia.org/wiki/Georgius_Agricola. Public domain. (b) Paracelsus—Figure from Paracelsus, Wikipedia—https://en.wikipedia.org/wiki/ Paracelsus. Public domain

4.2 Attitude Towards Radiation Before World War II Both the discovery of X-rays and radioactivity created massive enthusiasm. New, unusual radiation created amazing possibilities. During the first years, radiation’s positive properties and possibilities, including therapeutic ones, were actively discussed. Of course, the ability of new rays to penetrate the body, in other words, the diagnostic capabilities of radiation, made the strongest impression. Simultaneously information about the damaging factors of the effects of radiation on the body began to appear. But this information either did not reach the public at all or reached it in a highly deformed, smoothed form. Most likely, the public did not want to hear anything defaming such remarkable discoveries. Moreover, even scientists, pioneers in studying and applying these new phenomena, were mainly fascinated by new possibilities and neglected the dangers they understood, which cost them their health and even their lives.

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The attitude of researchers of radioactivity to the biological effects of penetrating radiation is characterized not by caution but by the feverish curiosity with which they experimented on themselves. The hazardous action of radiation was ignored mainly by both physicists and physicians.

4.2.1 Experiments on Oneself Let us give examples of two self-experiments described in scientific literature, which two great physicists carried out. The first experiment on oneself with the result described in the literature was an unintentional experiment of the discoverer of radioactivity A. Becquerel. He received a radiation burn on his skin from a source of radium obtained from the Curies, which he carried for some time in his vest pocket. Becquerel used this source for lecture demonstrations. As the daughter of Marie and Pierre Eva Curie writes in her book about her parents, after discovering the burn, Becquerel comes both in delight and fury. Becquerel died just 12 years after his discovery at the age of 54. Although the cause of his death has not been precisely determined, serious burns and scars caused by his work with radioactive materials were observed on his skin. Perhaps the consequences of this work largely determined the cause of his death. Pierre Curie conducted a conscious experiment—a textbook example of a radiation experiment conducted by a physicist on himself. When the physiological action of the radium rays became apparent, Pierre, neglecting the danger, exposed his forearm to the action of radium for several hours. To his joy (!), the area of the skin was damaged. For several months, P. Curie, like a real scientist, observed and described in detail the state of the radiation wound. Appeared in the reports of the Academy in 1901, the results of the experiments of P. Curie and H. Becquerel made a strong impression on scientists. They stimulated further research on the medical effects of radiation.

4.2.2 Marie Curie It is known that Marie Curie also received severe burns, transferring several centigrams of a very active substance in a sealed test tube. Marie’s own story tells about the situation in the laboratory of the Curie spouses: “We spent all our days in the laboratory … and we happened to have breakfast there simply, like students. Complete peace and silence reigned in

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our miserable shed; it happened when we only had to follow the progress of that or another operation; we walked up and down the barn, talking about our present and future work, chilled, we refreshed ourselves with a cup of tea right there, by the stove. In our common, unified hobby, we lived like in a dream… We used to come back in the evening after dinner to take a look at our possessions. Our precious products, for which we had no storage, were laid out on tables and boards, their faintly luminous points visible on all sides, seeming to hang in the dark, they always aroused in us a new excitement and admiration.” And one more thing: “During our work with very active substances, we experienced various types of their effects. Hands, in general have a tendency to peel; the ends of the fingers holding test tubes or capsules with highly active substances become hard and sometimes very painful; in one of us, the inflammation of the tips of the fingers lasted two weeks and ended with the skin coming off, but the painful sensitivity disappeared only after two months.” Marie Curie’s cataracts in both eyes were another radiation-related nuisance. Back in 1920, the doctor warned her that little by little, she would find herself in darkness. Marie Curie died before she was completely blind. Already after the damaging factors of radiation were discovered, Marie Curie “works with great haste and with her inherent negligence. In relation to herself, she does not comply with the safety measures that she strictly prescribes to her students.” Marie Curie either did not think about the dangers of radiation injuries or avoided this thought. Marie Curie died at the age of 67 due to chronic radiation sickness. Pierre Curie died in a road accident in 1906, but judging by the notes of their daughter Eva, he had radiation sickness in some form.

4.2.3 Thomas Edison and Clarens Dally The great American inventor T. A. Edison always kept a close eye on the latest advances in science. In particular, he worked with Crookes tubes, and then with X-rays, when a message was received about the discovery, and made certain improvements to the design. The portable X-ray apparatus he designed was already demonstrated in May 1896 at an exhibition in New York. The demonstrations were led by Edison’s assistant, glassblower Clarence Dally. Historians of science report that Dally liked to look at his own hands in X-rays. As a result, his left hand and several fingers on his right hand were amputated. But this did not stop carcinoma development, and in 1904, Dally died. He was the first victim of ionizing radiation, at least in the United States.

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After that, Edison stopped all work with X-rays. According to modern estimates, Dally received a dose of about 30 Grays on his hands.

4.2.4 Elizabeth Fleishman One of the first radiation victims was the famous American radiologist, Elizabeth Fleischman, the first woman to die because of radiation. Beginning radiography in 1896, shortly after Röntgen’s discovery was reported, Elizabeth Fleischmann quickly became one of the most accomplished radiographers in a hitherto male-dominated field. She became known as “The woman who gets the best radiographs in the world.” The first effects of radiation exposure appeared in 1904. The only way to save life was amputation. So, Fleishman lost her right arm up to her shoulder. She continued to work, now taking all precautions, but it was too late to repair the damage received during the early work, it turned out to be impossible. Fleishman died in 1905.

4.2.5 Nikola Tesla The boom that the discovery of X-rays produced worldwide also captured Nikola Tesla. At first, Tesla was sure that X-rays were absolutely harmless. Moreover, he was even inclined to believe that they had a bactericidal effect. However, as an honest researcher, he described the discomfort that he had during the experiments: some soreness in the forehead, above the eyes. He admitted also the possibility of a detrimental effect on the skin but associated this not with radiation, but with the influence of ozone, which was formed during the experiments. Soon Tesla changed his original opinion, realizing that the radiation was not at all as harmless as he thought. He experienced this himself. He irradiated his head, eyes, and hands and recorded his sensations and results. In May 1897, his article “On the harmful effects of Lenard and Roentgen tubes” appeared. Perhaps, this was one of the first attempts in science to comprehend the effects of X-rays on the human body. After one of the experiments, Tesla notes, his irradiated hand became very red and swollen. One of his assistants was badly injured when exposed to radiation. As far as is known, Tesla himself avoided serious health problems by sitting under his apparatus for several hours a day. Nikola Tesla died in 1943 at the age of 86 due to thrombosis of the heart vessels. This happened almost 50 years after his intensive work with X-rays. An idea of the work of radiologists with equipment can be seen in Fig. 4.2.

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Fig. 4.2  Taking an X-ray image with early Crookes tube apparatus, the late 1800s. The Crookes tube is visible in the center. The standing man is viewing his hand with a fluoroscope screen. The seated man is taking a radiograph of his hand by placing it on a photographic plate. No precautions against radiation exposure are taken; its hazards were unknown at the time. Figure from X-ray, Wikipedia—https://en.wikipedia.org/ wiki/X-­ray. Public domain

But even the damaging effect of radiation was sometimes interpreted as a positive effect. The founder of the idea of radiation hormesis, Thomas Lucky, whose ideas are described in Sect. 8.4, notes that already in an 1896 article, data were given on the activation of immunity by ionizing radiation. The sterilizing effect of radiation was also noted. The positive effect of the destructive effect of radiation is noted in the information about Emil Grubbe.

4.2.6 Emil Grubbe Currently, in some materials about the history of the discovery and development of X-rays, the phrase appears: “So, in 1895, Röntgen’s assistant William Grubbe received a radiation burn of his hands while working with X-rays, ….” The reality of such an event with Grubbe caused the author serious doubts. As you know, Röntgen discovered unknown radiation late on the evening of November 8, 1895. From that moment, while studying a new phenomenon, he practically did not leave the laboratory until the end of December and carried out all the measurements alone, without assistants. So, in 1895, it is

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unlikely that anyone other than Röntgen himself had time to work with X-rays. But maybe it’s a mistake in the date, and Grubbe got these burns later. The author began to look in the literature for reports of assistants, mechanics, glassblowers, and laboratory personnel named Grubbe, who had ever worked with Röntgen, and nowhere did he find such a surname. Unable to deal with the problem himself, the author requested the Röntgen Museum in Germany in Röntgen’s hometown of Remscheid and quickly received a response from the museum director, Dr. Uwe Busch. It turned out that indeed, there had never been any Grubbe next to Röntgen. However, a certain Grubbe—Emil Grubbe, a German immigrant, still existed, he lived in Chicago and really was using X-rays for cancer therapy, and really received serious radiation burns of his hands, but it was not William, but Emil, and not in Germany, but in Chicago, and not Röntgen’s assistant, but a college student, and not in 1895, but in 1896. By the time the news of Röntgen’s discovery reached America, Grubbe, a student at the homeopathic Hahnemann Medical College in Chicago, had been experimenting with Crookes tubes for some time. He immediately assembled the X-ray machine and began to work with it. Several times a day, he tested the “penetrating power” of his new pipes with his fingers. During two weeks of such work, purulent erythema developed on his left arm. With it, he went to the doctor. After examining the patient, i.e., E. Grubbe, professors of the Hahnemann Medical College. J.E. Gilman, A.C. Halphide, and R. Ludlam, in particular, noted “… any physical agent capable of doing so much damage to normal cells and tissues might offer possibilities, if used as a therapeutic agent, in the treatment of pathologic conditions in which pronounced irritative, blistering, or even destructive effects might be desirable.” And then begins what can be called a legend or myth. As if after a consultation, the professors referred a fifty-five-year-old patient, Mrs. Rose Lee, to Grubbe with an inoperable carcinoma of the left breast. On January 28, 1896, Grubbe allegedly conducted the first session of X-ray therapy, and this event claims to be considered the first medical procedure in the history of science. Irradiation lasted an hour and was followed by another seventeen of the same sessions. The next day after the start of Rosa’s irradiation, Grubbe allegedly saw an octogenarian Mr. Carr with extensive ulcerous lupus vulgaris on his face and neck and invited him to the irradiation procedures, which continued until mid-February. Grubbe stated that he treated many patients between 1896 and 1898, after which he opened his own X-ray laboratory. Grubbe did not publish any results of the treatment of either Rosa Lee, Mr. Carr, or other patients until 1930. He explained this by saying that he received

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a medical degree only in 1898. Subsequently, he quite successfully led the X-ray clinic and the radiological school, but he claimed to be the “father of radiotherapy.” But this circumstance is subject to very serious and justified doubts. It is not very clear how professors could send patients for treatment to a laboratory chemist. Criminological searches in the archives for information about Rose Lee and Carr, in particular, certificates of their death, did not give anything. Historians of science Nancy Knight and J.  Frank Wilson in the paper Early Years of Radiation Therapy cite other intriguing circumstances in the search for traces of Grubbe in radiology, as well as his life and death. Radiation played an evil role in the life of E. Grubbe. He underwent 83 surgeries (more than a hundred in other sources). His face was seriously deformed due to cancer. He became sterile and his marriage was childless. In his autobiography, he wrote “I will die due to the influence of early uncontrolled exposure to X-rays. Like many of the early pioneers, I became a victim of science, a martyr of X-rays.” Grubbe died of metastases in 1960 at the age of 85. According to modern estimates, he received doses of the order of 30 Gy. Emil Grubbe is considered one of the pioneers in the development of medical applications of X-rays. He has a quite positive Wikipedia page, as well as an article in the journal Science under the characteristic title “Pioneers of Radiation Therapy,” although his very first works are questioned. However, his activities are also characterized by another, also the very characteristic title of an article on the Russian Internet by M.  Shifrin: “Radiologist—Munchausen.” The result of the early period of radiation development is, in a sense, rather sad. Both physicists, who studied radioactive radiation and doctors who used this radiation, worked with them for the first years without any precautions and protection. Patients were also not protected from side radiation. By screening their patients, the doctors themselves received a certain dose of radiation every day. The hidden harm caused by these rays accumulated from day to day. Ten to 15 years after this practice, a mass defeat of radiologists with malignant tumors began. Many enthusiasts of this new diagnostic method died within a few years.

4.3 The Eben Byers Case In Sect. 3.6, we talked about one of the radioactive preparations, which, according to the assurances of the manufacturer’s advertising, cured many, almost all diseases, about Radithor, radium water. It became famous, not because of its healing properties, but vice versa, because of the destruction

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that it made in the body of one well-known and before that healthy, athletic man, Eben Byers. E. Byers was a famous sportsman, the champion of the National Amateur Golf Association, and quite a successful businessman, he was the president of Byers Steel Company. In 1927, he accidentally fell and injured his arm. Over the next few weeks, he began to complain of constant pain and a general run-­ down feeling that was affecting his athletic performance. In early 1928, Byers approached physiotherapist Charles Moyar. Moyar offered to try a new patent remedy that appeared on the market only in 1925, radioactive water Radithor. Byers followed his doctor’s suggestion and tried Radithor. He felt it was actually improving his overall health greatly. The company recommended drinking a bottle daily, but Byers preferred to increase the dose and began ingesting large quantities—as many as three bottles a day. He claimed to feel invigorated and restored and recommended Radithor enthusiastically to his high-society friends. He sent cases of it to his business partners and girlfriends and, as W.  Macklis wrote, even fed it to his racing horses. Totally Bayers consumed up to 1500 bottles. About 2 years after he had begun taking Radithor, Byers told his private physician, Joseph Wheelwright, that he had lost “that toned-up feeling.” He began to lose weight and complained of headaches and toothaches. He was told that he had a bad case of sinusitis and eventually, his teeth began falling out. Despite the treatment, Bayers’ health continued to deteriorate, and on March 31, 1932, at the age of 52, he died. He died of multisystem failure, the victim of a mysterious but relentlessly progressive syndrome involving multiple areas of skeletal and soft-tissue necrosis, metabolic wasting, and bone marrow dyscrasia. According to the terminology of the time, the accepted diagnosis of Byers is radioactive poisoning. A Wikipedia article on Byers claims that the cause of death was actually cheekbone and brain cancer. It is unlikely. Very little time elapsed between the beginning of the use of Radithor and death (1928–1932). As is known (see Sect. 6.4, Fig. 6.6), solid cancer has a very significant latent period, tens of years. Here is the company’s owner that produces the Radithor, William Bailey, who also consumed the Radithor in large quantities, died of bladder cancer on May 16, 1949, in ~20 years after use. According to Macklis, he was a person who claimed to have consumed more radium water than any living man.” Due to Byers’ fame, information about his death spilled into the pages of newspapers and magazines. His death made a lot of noise and caused a serious

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blow to the production of radium water that contributed to the cessation of the production and sale of radium water. Byers’ body was exhumed in 1965 to determine the residual activity of the body. It is known that after oral consumption, approximately 20% of the administered radium remains in the body. Over the entire period of drinking radium water, Byers’ body received ~35 million becquerels (1 millicurie) of radium. The body of the company’s founder, William Bailey, was also exhumed in 1970, and the residual activity of his body was also measured. Estimates indicated that William Bailey’s consumption of radioactive materials was ~11 million becquerels (300 microcuries) of radium. Section 7.2 shows that based on a study of the so-called radium girls, the limit value below which radium does not cause any, including long-term, effects, is 3.7 million becquerels (100 microcuries). Both Bayers and Bailey have markedly exceeded this limit. The tragic death of the famous millionaire Eben M.  Byers in 1932 as a consequence of radium poisoning became a widely known event that alerted both the public and the medical community of adverse radiation effects. This event probably ended the era of the so-called mild radium therapy. It became one of the first signals, the sum of which, after the Second World War, led to widespread radiophobia. Discussing the events of almost a hundred years ago, the author considers it necessary to remind readers of the position, repeated many times in this book, that small doses of radiation are safe and even beneficial, while large doses are dangerous and harmful. It is difficult to say what would have happened to Byers’ health if he had limited himself to one bottle a day instead of three. A detailed epidemiological survey of Radithor consumers has not been conducted. Recall that for the entire period of operation, the company that produced radium water has sold more than 400 thousand bottles. This means that thousands of people consumed Radithor. It is known that one person suffered from this—Eben Byers. In the 1960s, well-known scientist, an American nuclear physicist and pioneer of nuclear medicine, professor Robley Evans, emeritus director of the Radioactivity Center at the Massachusetts Institute of Technology had investigated 29 patients (21 living and eight postmortem) of Radithor poisonings, but very few of these individuals were ever publicly identified and their health was described. There were only rumors about the health problems of a few more people. In the report of R. Evans, there is a person with the number 01–017 (real names were classified). In 1926 when she was 43 years old, her physician suggested she try Radithor. This she took

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over a period of 3 years, starting with one bottle daily for nearly a year and then gradually tapering off in frequency during the second and third years. She believes that she must have drunk between 400 and 600 bottles during this time. In 1962 she was 79 and yet a healthy-appearing woman, healthy and spare. If Byers, instead of three bottles of Radithor, drank at least one bottle of whiskey a day, he would also die quickly, not necessarily from “radiation poisoning,” but, for example, from liver cirrhosis, and there is no doubt that some individuals drink liters of alcohol, get sick, and die. In particular, according to the US National Institutes of Health, about 88,000 people die yearly from excessive alcohol consumption. But whiskey (rum, gin, tequila, cognac, vodka) is not forbidden.

4.4 The Case of “Radium Girls” A noticeable sobering of society from the enthusiasm for radiation and the beginning of the formation of radio-phobia was facilitated by the so-called case of radium girls. The history of the discovery of the biomedical effects of incorporated radionuclides in the body differs significantly from the history of understanding the same effects when exposed to external radiation. The damaging effect of X-ray radiation manifested itself in the very first year after the discovery. In the case of internal exposure, it took about two decades to come to an understanding of its consequences. This is due, firstly, to the much rarer cases of a radionuclide entering the body. Secondly, it reflects one of the most characteristic features of the toxicology of internal emitters. With moderate consumption, the effects of exposure appear with a large shift in time. The case of the “radium girls” is one of the earliest and most famous cases of radium damage to the body. The Radium Luminous Materials Corporation, which was reorganized in 1921 into the U.S. Radium Corporation, has been producing watches since about 1915 with radium-based permanent luminous composition applied to the numbers and hands. Permanent light compositions are obtained by mixing a radioactive substance with a phosphor and a binder. Radiation from the nuclei of a radioactive substance excites phosphor, which glows with visible light. In the light compositions produced at the first stages of mastering this technology, the radioactive component was natural radioactive isotopes, most often radium.

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It is clear that elements of instruments and indicators glowing in the dark with visible light without additional illumination can be very useful and even necessary, especially in military affairs. The first light compositions were used to illuminate watch dials in the dark, but over time, the circle of use expanded. Subsequently, they made compass needles, aircraft instrument scales, toggle switches, sights—rear sights and front sights, scales in military installations, etc., visible in the dark. An example of a dial with luminous markings is shown in Fig. 4.3. Young women worked on the coloring of the dials. For painting, camel hairbrushes were used, when painting, they were disheveled, and the workers regularly licked them to straighten them. Different workers licked the brush from 6 to 15 times per dial. Estimates show that female workers ingested approximately 125–500 mg of radioactive liquid daily in this way. Workers received additional external exposure from cans of radioactive paint on the worktable and from products manufactured during the working day, which remained near the workplace of each worker. This is seen in Fig. 4.4, showing one of the workshops of a factory for the production of luminous dials in Illinois in 1925. There were many such factories in the USA, and they employed thousands of women. Over time, the workers began to develop lesions of the lips and the jaws, which turned into osteosarcomas. Several workers have died. The understanding that the health of women working in factories for producing luminous dials, connected with radioactivity, appeared in 1924. Doctors T. Bloom and

Fig. 4.3  Compass with radioactive markings on the dial. The author’s own compass, bought in the forties of the last century, with which the author traveled through Siberia, Central Asia, and the Caucasus

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Fig. 4.4  The workshop of the factory for the production of luminous dials in Illinois in 1925. Next to each worker is a box with ready-made dials. Figure from Chicago Great Lakes Region/National Archives—https://www.archives.gov/chicago/research. Public domain

then F. Hoffman drew attention to the uniformity of deaths of sick women and associated this with radionuclides included in paint composition. The first patients examined quite thoroughly using biopsies for anatomical and radiochemical analysis were reported by physician and pathologist H.S. Martland. In 1926, one of the U.S. Radium Corporation Grace Fryer, who developed a sarcoma of the lower jaw, went to court seeking compensation. Then four more workers joined the suit. After long litigation, after the involvement of New York human rights activists, the case went to court. By this time, the plaintiffs were already so weak that two of them were brought to court on a stretcher and did not have the strength to raise their hands to swear on the Bible. The lawsuit was settled out of court, and the “radium girls” case became the reason for the adoption of laws on industrial safety. The inventor of luminous dials, Sokhotsky himself, died in November 1928, officially becoming the 16th victim of radium poisoning. After finding out the source of the danger, all the dial painting shops were reconstructed and thoroughly cleaned, it was forbidden to lick the brushes, and by the end of the 1920s, the safety problem was solved. Let us note one more curious situation connected with luminous paints and characterizing the attitude towards radioactivity at that time. The U.S. Radium Corporation sold them for general use. The kit included a small amount of UNDARK luminous paint, a bottle of binder, a thinner bottle, a

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mixing cup, a glass stirring stick, and a camel hairbrush. This set costs $3 in the USA. The listed radiation events, as well as some others, which it was impossible to talk about here, in principle, did not change the generally positive attitude towards radiation. Only the Second World War, the real use of nuclear weapons, and numerous casualties not only from explosions but mainly from their consequences, from radioactive fallout, led to a sharp change in the mood in society. Let’s see how it happened.

4.5 Nuclear Bombardment of the Japanese Cities Perhaps one of the most deafening impressions was made on humankind by the nuclear bombing of the Japanese cities of Hiroshima and Nagasaki in 1945 at the end of the Second World War, which served as the start of radio-­ phobia that gripped humankind in the next half-century. The same bombing provided the wealthiest information on the health effects of nuclear radiation (more on this in Chaps. 7 and 8). Historians and politicians are still arguing about the advisability of using atomic weapons in that war. Supporters of the bombing claim that by such actions, they demoralized the leadership of Japan and inclined it to a quick surrender. It is believed that the atomic bombing prevented significant losses of both American and Japanese troops and the population of Japan during the planned landing of American troops on the Japanese islands. Opponents of the bombing insist that the same goals could have been achieved by conventional bombing or a demonstration of new capabilities somewhere on a desert island. Thus there was no military need for them. The opinion is expressed that the atomic bombing was supposed to show the then ally, but the expected rival—the USSR, that the United States was far ahead of the USSR in creating weapons of tremendous destructive power. It was assumed that the USSR would need 10–15  years to overcome the American monopoly on nuclear weapons. In particular, the eminent English scientist Bertrand Russell, in his speech in 1948, stated that from a moral point of view, it would be less dangerous to start a war before the USSR acquired an atomic bomb because in the war against the USSR, which did not yet have an atomic bomb, the victory of the West will be faster and bloodless. Immediately after the atomic bombing of Hiroshima and Nagasaki from 1945 to 1948, Russell published articles arguing unequivocally that it was

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morally justified and right to start a war against the USSR using atomic weapons. Regardless of the motives, it is clear that this bombing was an absolutely barbaric act, resulting in the death or subsequent suffering of a huge number of civilians. It should be noted that if in Nagasaki a bomb exploded over an industrial zone with many military enterprises, then Hiroshima was a much less militarized city. The bomb exploded over the center, hitting mainly civilians.

4.5.1 The Damaging Effects of a Nuclear Explosion In a nuclear explosion in a relatively small volume of about ten centimeters, an enormous amount of energy is released in an extremely short time (fractions of microseconds). The energy of a nuclear explosion is conditionally measured in units of TNT equivalent, i.e., the amount of trinitrotoluene (TNT) that must be exploded to release the same energy. Let us explain what the order of magnitude of the energy of a nuclear explosion is. One kiloton of TNT corresponds to an energy release of the order of 4 Terajoules = 1 Teracalories (the decimal prefix Tera means a million million or a thousand billion, or 1012). One Megaton of TNT releases energy of the order of 4·1015 Joules (4 Petajoules), which is several times more than the daily electricity consumption in a small European country. As a result of releasing a colossal amount of energy in an extremely short time (fractions of a microsecond), a bright flash of light appears. It is no coincidence that the Austrian journalist and writer Robert Jungk called his book “Brighter than a Thousand Suns.” All substances that make up the structure of a nuclear charge, as well as a certain amount of surrounding substances (air during an air explosion, soil, and supports during a ground explosion) are heated to a very high temperature and turn into an expanding plasma. At the center of the charge, the temperature rises to hundreds of millions of degrees, and the pressure rises to 1012 atm. This temperature exists at the center of the sun. The resulting extremely hot and brightly luminous mass of substances is what is called the nuclear fireball. The fiery cloud of the explosion, expanding, cooling down, and floating up, initially spherical, takes the form of a mushroom cap. If the explosion was close to the surface of the earth, the explosion cloud touches the ground and draws in a huge amount of soil and everything that was under it. This is how the “leg of the mushroom” is formed, and the nuclear explosion takes on the well-known mushroom shape with a thick stem like a boletus. If the explosion

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occurred high, then due to the reduced pressure in the expanding cloud, dust is drawn in from the surface of the earth, and a leg still appears, but thin, like that of a toadstool mushroom. Light radiation is the first damaging factor in a nuclear explosion. The duration of light radiation is from fractions of a second in low-power charges to tens of seconds in charges of megaton power, and it propagates at the speed of light. It can cause skin burns, eye damage, and ignition of combustible materials. It is no coincidence that the Austrian journalist Robert Jungk, struck by the descriptions of an unusual phenomenon, called the book that appeared shortly after the first nuclear bombings, “Brighter than a Thousand Suns.” The temperature of the outer part of the luminous area is 6000–8000 degrees. This is more than the surface temperature of the Sun. True, it should be noted that cloudiness, smoke, and uneven terrain can significantly weaken the damaging effect of light radiation. The second effect of a nuclear explosion is the blast it generates. The blast originates from the rapidly expanding fireball, which creates a pressure wave front moving rapidly away from the point of detonation. Blast is measured by overpressure (that is, pressure over and above atmospheric pressure). Overpressure of about 0.3–0.4 atm perforates the eardrum, about 1 atm— causes serious lung damage, and about several atm—breaks and tears the body. Near the explosion’s center, the shock wave’s propagation speed is several times higher than the speed of sound (for air at 20 °С vsound = 343.2 m/s = 123 5.6 km/h). As the distance from the explosion increases, the wave propagation speed decreases rapidly. At large distances, its speed approaches the speed of sound in the air. The shock wave of medium-power ammunition passes the first kilometer in 1.4 s; the second—in 4 s; the fifth—in 12 s. The third damaging factor is ionizing radiation. Penetrating radiation consists of gamma quanta and neutrons emitted from the zone of a nuclear explosion. About 5% of the total energy appears immediately as invisible “initial” or “prompt” nuclear radiation. Neutrons make up about 30% of the radiation flux, the rest is gamma quanta. Another factor in the action of radiation, which is significantly dependent on the height of the explosion, is radioactive contamination as a result of the fallout of radioactive substances from the cloud of a nuclear explosion with the formation of the so-called radioactive trace along the wind. Nuclear explosive devices—a bomb, a warhead, a projectile—have very little activity before the explosion, just like nuclear fuel before being loaded into a reactor at a nuclear power plant. But during the explosion of nuclear charges, radioactive fission products appear in vast amounts (up to three hundred different radioactive nuclides).

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In addition to these products, two more types of radioactive substances are formed in the explosion. First, the products of activation of the surrounding elements by the neutrons of a nuclear explosion. The fact is that neutrons produced in a nuclear explosion in large quantities are capable of creating radioactive substances when interacting with many different atoms, this is called activation. The second additional source of radioactivity is the original substance that has not undergone fission reactions—uranium and/or plutonium. Recall that in the very first atomic bomb detonated over Hiroshima, out of 64 kg of uranium contained in the bomb, a little more than 800 grams participated in nuclear fission chain reactions, which, in fact, released the energy of the explosion. The explosion dispersed the rest of the highly enriched uranium. The plutonium bomb detonated over Nagasaki turned out to be more effective, in which 16% (~ 1 kg) of about 6 kg of weapons-grade plutonium passed into the explosion energy. But here, too, most of the fissile material is dispersed during the explosion. Work on increasing the effectiveness of nuclear warheads continues to this day, but naturally, in an atmosphere of strict secrecy. Dispersed uranium and plutonium are weakly radioactive substances, but they have a very long half-life, for plutonium, it is ~24 thousand years, and for uranium-235—about 700 million years. Radioactive substances in the explosion cloud, brought to an atomic state by high temperature, stick to dust particles. Rarefied heated air, carrying radioactive dust raised from the ground, reaches a height of 10–15 km in a few minutes. Further, the radioactive cloud spreads over hundreds of kilometers and is displaced, mainly under the influence of the wind. Because the direction and strength of the wind can vary markedly at different heights, radioactive materials are carried over long distances. Large dust particles carrying radioactive atoms fall relatively close to the explosion’s epicenter, creating the so-called local fallout. Smaller ones go further. The fallout of radioactive substances, which is significantly heterogeneous in area, is facilitated by rains. In the cloud propagating in the air, there are many particles of burnt materials—soot. Therefore, the rain that can come from condensed moisture has a dark or even just black color. So, it turns out, the so-called black rain. The smallest particles are carried into the stratosphere, can remain there for years, and gradually fall almost evenly over the globe, creating the so-called global fallout. Normal precipitation—rain, snow, and fog accelerate fallout. After air nuclear explosions, especially of large caliber, radioactive particles can be carried high into the troposphere and spread over vast areas. Abundant fallout for tens of hours can occur at distances of 500–1000  km from the explosion site and can last for 2–4 weeks. Some radioactive substances make

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a complete revolution around the globe in a few days. Another part of the radioactive material can be thrown into the stratosphere. Within a few months after a nuclear explosion, radioactive substances begin to fall to the surface of the Earth, spreading almost throughout the globe, forming the so-called global fallout. So, the main damaging factors of a nuclear explosion are shock wave, light radiation, penetrating ionizing radiation, and radioactive contamination of the area.

4.5.2 Nuclear Bombs The two bombs used in Japan differed in their principle of action. The first was uranium, gun type. The creators did not doubt its action, the explosion over Hiroshima was the first explosion of a uranium bomb. However, its effectiveness was very low. Only less than 1.5% of uranium experienced fission and passed into the energy of the explosion. An implosion-type plutonium bomb was detonated over Nagasaki. The reliability of such a bomb was in doubt. Therefore this bomb was tested at the Alamogordo test site in the desert of Jornada del Muerto in southeastern New Mexico, USA, on July 16, 1945 (Trinity test). The plutonium bomb proved to be about ten times more effective than the uranium bomb. Both bombs had a comparable length—a little over three meters, and a comparable weight of about 4–4.5 tons, but differing in diameter by about two times (71 cm—uranium and 152 cm—plutonium. Therefore, the uranium bomb was called “Little Boy,” and the plutonium was “Fat Man.” The first atomic bombs are shown in Fig. 4.5.

Fig. 4.5  The first atomic bombs: Fat Man—on the left and Little Boy—on the right. (a) Fat Man—Figure from Fat Man Fat Man, Wikipedia—https://en.wikipedia.org/wiki/ Fat_Man. Public domain. (b) Little Boy—Figure from Little Boy, Wikipedia—https:// en.wikipedia.org/wiki/Little_Boy. Public domain

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The uranium atomic bomb “Little Boy” with a TNT equivalent power of ~16 kt was dropped on Hiroshima on the morning of August 6, 1945. All the uranium-235 accumulated by that time was used to create this bomb. The Enola Gay B-29 bomber, under the command of Colonel Paul Tibbets, took off from the American air base on Tinian Island in the Marianas group in the Pacific Ocean, located at a distance of about 2800 km from the target. The weather was good, visibility was excellent, aiming accuracy was high, and the area where Hiroshima is located was relatively flat. The dropped bomb instantly killed from 90 to 120 thousand people, wounded about 100 thousand, and caused extensive destruction in the city. On August 9, Nagasaki’s turn came. This time the Fat Man bomb was used. The original target that day was the city of Kokura, but it was obscured by clouds. In addition, the Japanese anti-aircraft artillery became more active, fighters rose into the air, and then the Bockscar bomber, under the command of Major Charles Sweeney, headed for Nagasaki. Kokura was lucky, but Nagasaki was unlucky. By the time the bomber approached, Nagasaki was also covered by clouds. Due to some technical problems, the aircraft ran out of fuel and could have problems returning to the airbase. At the last minute, a small window opened in the clouds, and the pilots saw the city and dropped the bomb. The power of this bomb is estimated at ~21 kt. Due to the peculiarities of the location of Nagasaki and low aiming accuracy, the lethal effect was lower than in Hiroshima, although the Fat Man’s power was higher. The explosion killed between 60,000 and 80,000. The location map of Hiroshima, Nagasaki, and Tinian Island is shown in Fig. 4.6. Both explosions were in the air, i.e., occurred over cities at a considerable height, over Hiroshima at an altitude of about 600  m, and over Nagasaki at ~500 m. The height of the explosion is chosen from the condition of maximum damage. In his book Nuclear Risks and Preparedness, the American officer and scientist Kevin Briggs gives an example: when a 500 kt bomb explodes at an altitude of 1.8 km, the threshold of serious damage to the human body is at a distance of about 5 km, with a ground explosion, the same damage is achieved at a distance of only 3.5  km. We have to admit that dozens, and maybe even hundreds of highly educated people develop theories, derive formulas, and carry out calculations aimed at solving the barbaric problem— how to kill more people, how to bring the greatest damage. By the way, it may be worth explaining why the alarm was not declared in the Japanese towns, why the population did not hide in bomb shelters, and why fighters did not fly out to intercept and anti-aircraft artillery did not

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Fig. 4.6  The Japanese cities of Hiroshima and Nagasaki, which were bombed on August 6 and 9, 1945, Kokura, which was the original target on August 9, Tinian Island, where the bomb was assembled, and bomber routes. Figure from Atomic Bombings of Hiroshima and Nagasaki, Wikipedia—https://en.wikipedia.org/wiki/Atomic_bombings_ of_Hiroshima_and_Nagasaki. Public domain

work. Japanese radars detected the approach of several enemy aircraft, but the already familiar bomber raids were carried out in large groups of tens or even hundreds of vehicles, and several aircraft were mistaken for reconnaissance aircraft. It was necessary to save fuel for refueling aircraft and anti-aircraft shells and not waste them on seemingly insignificant targets. No one could have imagined that just one plane that would drop just one bomb would cause such terrible destruction at that time. A typical case was described by the already mentioned Austrian journalist Robert Jung in his book “Brighter than a Thousand Suns.” For several hours after the disaster in Hiroshima, no one in Tokyo really knew what had happened there. But this was quickly understood by the famous Japanese atomic scientist Yoshio Nishina, who worked in the twenties with Niels Bohr. On

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August 7, before flying to Hiroshima, where he was called at the request of the General Staff, “he was standing on one of the streets of Tokyo, along with his student Fukuda, when a single American B-29 aircraft appeared in the sky. Residents of Tokyo are accustomed to massive raids. Since the newspapers had not yet received permission to publish any information about the new bomb, the city’s population paid very little attention to a lone enemy aircraft, which apparently had strayed from its group, but both scientists felt fear and ran in search of an air raid shelter. According to Fukuda’s account, their conscience was tormenting them at the time. Of all the people around them, they were the only ones who knew that even a single plane with a single bomb could cause a more terrible disaster than all the squadrons that participated in the previous raids put together. They wanted to shout to all these indifferent people: “Run for shelter! This may not be an ordinary plane and with not ordinary bombs!” But the General Staff strictly required them to keep all this a secret, even from their families. They had to keep silent. Fortunately, this time the atomic bomb was not dropped. But this lucky chance did not dispel the depressed mood. Professor Nishina never could then get rid of the feeling of guilt, from the feeling of betrayal in relation to their fellow citizens. Already the first reports of the aftermath of the bombing showed that the victims were showing previously unknown symptoms. Humankind first encountered a phenomenon later called “acute radiation sickness.” On October 12, 1945, the United States formed the Joint Commission for the Investigation of the Effects of the Atomic Bomb to investigate the new phenomenon. At the end of 1946, the Atomic Bomb Casualty Commission (ABCC) was formed in the United States. It was later reorganized into The Radiation Effects Research Foundation (RERF), a joint US-Japanese organization. This organization has carried out and still continues to carry out the main work on the study of the impact of atomic bombings on the health of the population of Japan. The organizations mentioned above were engaged only in studies of the consequences of nuclear bombings but did not participate in the organization of treatment, social assistance, etc. The full participation of Japanese scientists in research became possible after the entry into force in 1952 of the San Francisco Peace Treaty when the occupation of Japan by the Allied forces ended.

4.5.3 Reaction to the Bombing in Japan In Japan, they did not immediately understand what had happened; many communication channels were disrupted. Only after Nagasaki did the Japanese

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leadership begin to analyze the new situation seriously. Long discussions did not yield any results, and on August 10, Prime Minister Kantaro Suzuki asked the emperor to decide. On August 15, Emperor Hirohito personally announced that further resistance was futile: “… I do not want any further destruction of culture, nor any additional misfortunes for the peoples of the world. In this case, we have to bear the unbearable”. On September 2, 1945, an act of unconditional surrender was signed aboard the USS Missouri. The war was over. Not everyone agreed with this decision. For example, Vice Admiral Takijiro Onishi chose hara-kiri. The country was seriously preparing to repel the invasion. The fall of the first atomic bomb did not break the spirit of resistance. Reports appeared in the press that the Americans had used up all their atomic bombs, that they were very expensive, and that the Americans would not soon produce new ones. But the Japanese had a wise emperor and now Japan is a rich and prosperous country. For some time after the disaster in Hiroshima, no one in Tokyo really knew what had happened there. On the morning of August 7, Deputy Chief of the General Staff Kawabe received a completely incomprehensible report: “The city of Hiroshima was completely destroyed in an instant by one bomb.” When the famous scientist Professor Yoshio Nishina, called to the General Staff, arrived there, he was asked, “Can you make an atomic bomb in six months? Under favorable circumstances, we could hold out this period.” Nishina replied, “Under the current conditions, six years would not be enough. In any case, we do not have uranium.” And when asked if he could offer an effective protection method against new bombs, Nishina replied, “Shoot down every enemy aircraft that appears over Japan.” The horror of the huge destruction became clear very soon. After a while, about months, it turned out that in addition to the most powerful explosion and sizzling thermal radiation, another one was added to the damaging factors—ionizing radiation. In Japan, this was understood much earlier than in the rest of the world. Indeed, certain types of nuclear charges and certain detonation methods can create significant and long-term radioactive contamination of the area, and the doses received by the population in such cases would also be very significant. Some territories would have been uninhabited for a long time, for tens, and maybe hundreds of years. But, fortunately, the nuclear bombardments of Japanese cities were carried out in such a way that they did not lead to significant exposure of the part of the population that survived the explosions and subsequent fires and did not create significant radiation

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contamination. In our time, however, for a long time, both Hiroshima and Nagasaki are prosperous cities. And so, it turns out that the greater the destructive power of nuclear weapons, the less role radiation plays. We will discuss these issues further in Chap. 7.

4.5.4 Reaction to the Bombing in the World In the world, the announcement of the end of the most difficult war was greeted with rejoicing. Reports of the atomic bombing were also welcomed at first. Many believed that with such powerful destructive forces, future wars were generally meaningless and, therefore, impossible. At least among the intelligentsia, it was clear that future wars with the use of nuclear weapons would lead to the end of civilization, which means there would be no more world wars. Another source of mass enthusiasm was information about discovering a new source of huge and inexhaustible energy, nuclear energy is a panacea. Humanity is waiting for what was called an “atomic utopia.” Newspapers and magazines were filled with articles about future atomic cars, airplanes, and all other atomic technology. The so-called atomic style appeared in dances. Shortly after the explosions, articles in American newspapers glorified the colossal explosive power of the new weapon and the unprecedented scale of destruction. The damage from the fires attracted much less attention; after the famous bombings of Dresden and Hamburg, it was difficult to surprise Americans with such consequences. The Americans blocked information about radiation contamination in every possible way: they censored the press, confiscated the reports of Japanese doctors, intimidated independent scientists, and misled the public. The authorities feared that reports of radioactive contamination of the area after the explosions could be interpreted as the use of weapons similar in their effect to poison gases condemned and banned after the First World War. However, little by little information leaked out. There were reports of special scientific groups sent to Japan to study the biomedical consequences of the bombing. Historians cite the entire August 21, 1946, issue of The New Yorker, dedicated to stories about the devastation of Hiroshima, as the first major step from admiration to disillusionment in the United States. Soon the articles of this magazine were published as a separate book: John Hersey, “Hiroshima.” But finally, the mood of radio-phobia swept over society after reports of the tragedy of Japanese fishermen who fell in the Pacific Ocean under the fallout of a nuclear explosion. For this, see Sects. 4.7 and 4.8.

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4.5.5 Reaction to the Bombing in the USSR Until the middle of 1945, research work in the USSR on the creation of the atomic bomb was carried out on a limited scale. According to experts who worked at that time, the government was not very trusting of intelligence reports about the prospects of Germany and the United States to create super-­ powerful weapons. Work on the creation of atomic weapons sharply intensified after the announcement of the testing of an atomic explosive device in the United States, especially after the nuclear bombing of Hiroshima and Nagasaki in August 1945. Only after that it became apparent that the miracle weapon was not a figment of the imagination of physicists. On August 8, 1945, the USSR entered the war with Japan. Due to the need to slow down the expression of pity towards Japan at the time when the war with her began, the reaction to the nuclear bombing in the Soviet press was very laconic. After the explosions over Hiroshima and Nagasaki, the situation in the highest echelons of power in the USSR was close to panic. The monopoly possession of nuclear weapons provided the United States with obvious advantages that they could, in principle, use. The well-informed British journalist Alexander Werth, a correspondent for The Sunday Times and BBC, the author of the book “Russia in the War 1941-1945,” wrote that the consciousness that the Americans had a monopoly on the atomic bomb disturbed Soviet public opinion. The press remained silent on this matter, and the copy of the English weekly “British Ally”, the first periodical in the USSR to include some details about Hiroshima and Nagasaki, was sold out with lightning speed. It is important to note that the entire history of the creation, improvement, and testing of nuclear weapons occurred in the conditions of the “cold” war. The vast majority of work on nuclear topics in the USSR was classified, and military applications were covered with a particularly cruel veil of secrecy. However, the atmosphere of secrecy was almost a universal rule of activity in many areas. Thus, spacecraft launches were reported only after launch. No one knew the name of Yuri Gagarin until his safe return to Earth. But despite the whole atmosphere of secrecy, information about new dangers penetrated society, naturally, often in a distorted form. Much in the country’s life was subordinated to preparing the Soviet Union for a nuclear war. Official standards for constructing industrial, military, and civil facilities are necessary for constructing shelters. All enterprises significant for the state

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in the USSR had mobilization plans, mobile reserves, and the resources to fully implement evacuation programs. In 1961, the USSR Civil Defense system was organized, the position of the head of civil defense was introduced, and full-time positions of civil defense engineers and instructors were introduced at enterprises and institutions. Schools held classes in basic military training, which were accompanied by exercises where schoolchildren acquired self-rescue skills in case of nuclear explosions. The population received some information about nuclear weapons and new dangers not only from rumors but also from books. Several books were published by the American physicist Ralph Lapp, who participated in the Manhattan Project: The New Force: The Story of Atoms And People (1953), Radiation: What It Is And How It Affects You (1957), The Voyage of the Lucky Dragon (1958). American science journalist William Laurence served as the official historian of the Manhattan Project. In 1946 he published a book “Dawn Over Zero: The Story of the Atomic Bomb.” Great public attention was attracted by the book of the Austrian journalist and writer Robert Jungk “Brighter than a Thousand Suns.” Already in November 1945, the so-called Smith report appeared, written by an American physicist, a participant in the Manhattan Project Harry Smith “Atomic Energy for Military Purposes.” So, there was where to draw grounds for radio-phobia. The era of general radio-phobia has been counted since the signing of the Test Ban Treaty in three environments (atmosphere, space, water) on August 5, 1963. In fact, the date of the treaty’s signing is when everyone, even the leadership of the leading countries, has already realized that it is time to end the Earth’s radioactive contamination.

4.6 Radiation Events in the USA It was at a time when the world was aware of what had happened in Hiroshima and Nagasaki that events occurred in the United States that added weighty grounds for the flaring radio-phobia. These events are associated with a new type of danger, that appeared with the discovery of a fission phenomenon. They are so-called self-sustaining chain reactions, in other words—criticality incidents.

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4.6.1 Otto Frisch The first radiation event was the case with Otto Frisch. In 1944 in Los Alamos, Otto Frisch, the famous physicist, conducted research of critical conditions on an installation with unshielded Uranium blocks, called “Lady Godiva.” Bending over the Uranium blocks, Frisch involuntarily performed as a neutron reflector and thus provoked a criticality incident. Frisch felt a heat stroke and immediately jumped aside thus stopping the reaction, and, by his estimations, he could have gotten a lethal dose just another couple of seconds. For just 2 seconds, Frisch got a daily dose of neutron irradiation that according to the standards for those years was allowable. One can assume that everything ended relatively happily, while the accident occurred in 1944 and Otto Frisch died in 1979 at 75.

4.6.2 Harry Daghlian, Jr. On August 21, 1945, at Los Alamos, the American physicist Harry Daghlian Jr. performed critical experiments by assembling a neutron reflector from blocks of tungsten carbide weighing 4.4  kg each around a spherical plutonium core. The mass of the nucleus was less than critical, but the neutron reflectors surrounding it could transfer the system to a critical state. The day before, two similar experiments were carried out quite successfully, and the next one was scheduled for the morning. But instead of waiting until the morning, Daghlian, violating safety regulations, started a new experiment alone late in the evening, which turned out to be fatal for him. Four layers of blocks had already been laid around the plutonium core, and the experimenter laid the last block of the fifth layer when he noticed a sharp increase in the readings of the neutron flux detector. Daghlian tried to remove the last block, but it slipped out of his hands and fell into the center of the installation, due to which the reaction instantly became supercritical. The plutonium core surrounded by part of the reflector blocks is shown in Fig. 4.7. An instantaneous chain reaction caused a flash of light, brightly illuminating the newspaper, which at that moment the guard was reading who sat 10–12 feet (3.5–4 m) from the facility with his back to it in the brightly lit lab room. Daghlian immediately pushed the last block with his right hand and then partially dismantled the installation. He estimated that he remained near the installation for at least 10 minutes. While Daghlian was trying to scatter the blocks, he received a lethal dose. Daghlian died 25 days after the incident.

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Fig. 4.7  A plutonium core surrounded by a part of the tungsten carbide reflector blocks, with which G. Daghlian experimented. Figure from Harry Daghlian, Wikipedia— https://en.wikipedia.org/wiki/Harry_Daghlian. Author: Los Alamos National Laboratory

4.6.3 Luis Slotin Wider known is another case—the death from radiation sickness of Louis Slotin, a Canadian physicist. Louis Slotin conducted experiments on the definition of critical parameters, first working in the association with Otto Frisch group with Uranium, then later with Plutonium. It was Slotin who was assembling a Plutonium sphere of the first test explosion “Trinity” in a desert near Alamogordo, New Mexico, on July 16, 1945. In the Spring of 1946, Louis Slotin was preparing for another job, and on May 21, he showed his critical experiment to his seven colleagues. One of those colleagues had to remove him from the position of leader of a group conducting critical experiments. Slotin’s experiment dealt with the Plutonium sphere with which Harry K. Daghlian also worked. Later the sphere was called “demon core” for its role in two lethal cases. This time Beryllium hollow hemispheres were used as a reflector. The plutonium core was embedded in the lower hemisphere, and the position of the upper Slotin was changing, fixing the lower position with the sharp point of a screwdriver. Suddenly the screwdriver slipped out of his hand, the Beryllium sphere dropped down on the ball and the conditions for criticality instantly appeared. The scientists

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present saw a bluish glow and felt a wave of heat. Slotin grabbed the upper Beryllium sphere and threw it down on the floor thus stopping the chain reaction. He hastened to take measures to check the doses for each of those present. Before this occasion, Louis Slotin regularly demonstrated in his laboratory the experiment of bringing a “diabolic ball” to the subcritical condition being able to keep the two hemispheres of the Beryllium reflector at a minimal distance from the ball. Richard Feinmann, as reported, called such experiments “tickling the dragon’s tail.” They say Enrico Fermi warned Louis Slotin that such practice won’t end well. Slotin in his experiments proved unacceptable negligence, thus endangering not only himself but also many of his colleagues in the laboratory. But as the incident happened Louis Slotin behaved quite heroically. His immediate reaction saved not only those who were observing his demonstration but also the whole laboratory and even, perhaps, the whole town. The position of the observers in the room was shown in Fig.  4.8, being reconstructed by marks on the floor. I pay special attention to the

Fig. 4.8  Position of the participants of the critical incident of May 21, 1946. The closest to the facility stood Louis Slotin. To his right, a little bit further stood Alvin C. Graves. Partly Slotin blocked Graves, this is not shown in the picture. Further counterclockwise stood S.A. Kline, D.S. Young, P.J. Cleary—the guard, T.P. Perlman, R.E. Schreiber, and M.E.  Cieslicki. Figure from Louis Slotin, Wikipedia—https://en.wikipedia.org/wiki/ Louis_Slotin. Public domain

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arrangement of the participants in the tragic experiment because it clearly illustrates the three great principles of radiation protection: exposure duration, distance from the source, and shielding. The exposure duration was shortened by Slotin himself, scattering the critical assembly. The exposure, which proved fatal to Slotin, had a markedly lesser impact on the health of others who stood further away from the radiation source. Finally, Alvin C. Graves, standing closest to the source of all the spectators, also remained alive, since Slotin shielded him from the radiation with his body. Eight people in the laboratory received various non-lethal doses; their state of health and fate are described in detail. One of them, Raymer Schreiber, even before this event, accompanied the plutonium core to the Pacific Island of Tinian, where the Fat Man bomb dropped on Nagasaki was assembled. Subsequently, Schreiber collected hydrogen bombs. He died in 1998 at the age of 88. Lous Slotin’s life and his death of irradiation became the subject of the novel “The Accident” (1955) written by an American writer Dexter Masters, a nephew of famous American poet Edgar Lee Masters. In this novel, Louis Slotin is portrayed under the name of Saxle. The Slotin case was also implemented in the movie “Fat Man and Little Boy” with Paul Newman starring as General Lesley Groves. Here Louis Slotin was presented under the name of Michael Merriman played by John Cusack. In 1999 on Canadian TV a documentary called “Tickling the Dragon’s Tail: The Mystery of Louis Slotin” was issued. The Slotin case served as a basis for many other art and documentary works. The play “Louis Slotin Sonata” by Paul Mullin was performed on several theatrical stages for at least 10 years in the USA. Louis Slotin was officially recognized as the hero of the United States. In 2002 his name was given to the asteroid discovered in 1995. After this event manual experiments were banned, and since then, similar research has to be conducted only by remote control.

4.7 Adventure of the Japanese Fishing Boat Fukuryu-Maru Some of the radiation events that took place in the 1930s, the Eben Byers case, the radium girls’ case, and some others that caused a gradual sobering from the rapturous state of radio-euphoria, nevertheless did not lead to a sharp change in mood. The nuclear bombings of Japanese cities aroused the

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world’s fear not so much of radiation as of atomic energy. Apparently, the main event that led to the fact that radio euphoria in the mass consciousness gave way to radio-phobia was the episode with the Japanese ship Fukuryu-­ Maru, which fell under radioactive fallout after a thermonuclear explosion on the Bikini Atoll. Until that time, a nuclear explosion was perceived as an ordinary explosion, only many orders of magnitude more powerful. Conventional bombing during World War II of the German cities of Berlin, Hamburg, and Dresden and the Japanese capital of Tokyo led to no less destruction and casualties than the nuclear bombings of Hiroshima and Nagasaki. Just for bombing with conventional bombs, thousands of sorties were required instead of one with an atomic bomb. The public did not know about the role of radiation as one of the damaging factors of a nuclear explosion, and the authorities did not report it. Nuclear weapons tests were shrouded in a veil of secrecy. Special organizations, of course, recorded the explosions themselves and analyzed the composition of the explosion products carried by the atmosphere and radioactive fallout, but the public was not informed about the results of the studies. In 1946, in the Pacific Ocean on the Marshall Islands, the United States began to conduct test explosions of atomic weapons, and in 1952, the turn of thermonuclear charges came. The tests were carried out in the lagoons of Bikini and Eniwetok atolls. See the Marshall Islands map in Fig. 4.9, and the map of Bikini Atoll in Fig. 4.10. The first thermonuclear explosion “Mike” with a capacity of 10.4 Mt was carried out on the Enewetak Atoll on November 1, 1952. The explosive device was a huge building the size of a house weighing 82 tons. Liquid deuterium was used as the hydrogen component in the device. Since the boiling point of deuterium is −254.5 °C, the device required serious cryogenic support. It is clear that such a device could not be either a bomb or a projectile, it served only to test the idea. This explosion almost evaporated the island of Elugelab, which, together with other islands, forms the Eniwetok Atoll. The first fusion device with solid fuel, lithium deuteride, which could already be a prototype military weapon, was detonated at Bikini Atoll on March 1, 1954. It was the Bravo explosion from the series Castle (Fig. 4.11). The specialists made a mistake in their calculations and instead of the estimated power of 6 megatons, the explosion produced 15 Mt. Mistakes were also made in predicting the weather. According to preliminary data, it was assumed that the wind would carry the products of the explosion to the north. But the wind suddenly changed direction, and a huge amount of sand and crushed coral from the bottom of the Bikini Atoll lagoon rose into the

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Fig. 4.9  Map of the Marshall Islands. The islands form two chains, the western one is called Ralik (sunset), and the eastern one is called Ratak (sunrise). They include 29 atolls and five islands. The atolls of Eniwetok and Bikini, where nuclear test explosions were carried out, are located in the northwestern part of the Ralik chain. The tab shows the islands’ position on a Pacific Ocean map. Figure from Marshall Islands, Wikipedia— https://en.wikipedia.org/wiki/Marshall_Islands. Public domain

atmosphere, rushed mainly in an easterly direction, and spilled out into the expanses of the Pacific Ocean. A blizzard of white ash carrying large amounts of radioactive material fell on the nearby inhabited atolls of Rongelap, Rongerik, Ailinginae, and Utrik. The distribution of fallout along the wind in an easterly direction is shown on the map in Fig.  4.12. The inhabitants of Rongelap, who were exposed to radioactive products of the explosion, quickly felt nausea, vomiting, and irritation of the eyes and skin. The population of Rangelap Island was evacuated 48 hours after the explosion, and Utrik Island, located further from Bikini, 72  hours later. During their stay under the influence of precipitation, the inhabitants of Rongelap received an average of up to 2 Sv. Apart from the population, 28 US citizens from the staff of the meteorology station at the Rongerik Atoll were also irradiated. They were transported

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Fig. 4.10  Map of Bikini Atoll. It consists of 23 islands surrounding a central lagoon. The total land area is 8.8 km2, the lagoon area is 594 km2, and the average sea depth in the lagoon is 35–55 m. The nuclear charge was installed on land near the island of Namu in the northwestern corner. After the explosion, a crater 2 km in diameter and 76 m deep was formed there (noted red star). An observation post was set up on Enyu Island in the southeast corner. Bikini Island, which gave its name to the atoll, its largest island, lies in the northeast corner. Figure from Bikini Atoll, Wikipedia—https://en.wikipedia.org/wiki/Bikini_Atoll, CC-BY 2.0; Source: Peter Minton (EVS Island)

by plane to the Kwajelain Atoll and then to the US Navy base for medical treatment. Increased doses were received by the test team personnel, who were in a protective bunker on Enyu Island on the opposite side of the atoll, and the crews of the ships providing testing. Among the American ships affected by radioactive fallout was the tanker Potapsko. On February 27, he was ordered to leave immediately for the base at Pearl Harbor in Hawaii at the highest possible speed. But the ship’s engine broke down, the speed dropped sharply, and on March 2, at about noon, it ended up in a cloud of products of a nuclear explosion. There was no means of decontamination on board. Estimates indicate that crew members received doses ranging from 3.3 to 18 cSv, depending on whether they were on or below deck.

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Fig. 4.11  The thermonuclear explosion Bravo at Bikini atoll on March 1, 1954. Figure from Marshall Islands, Wikipedia—https://en.wikipedia.org/wiki/Marshall_Islands. Public domain

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Ground Zero

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80 100 120 140 160 180 200 220 240 260 280 300 320 Distance from Ground Zero, miles

Fig. 4.12  Distribution of products of thermonuclear explosion Bravo in the atmosphere. The red circle marks the approximate position of the Fukuryu-Maru at the time of the explosion. Figure from Daigo Fukuryu Maru, Wikipedia—https://en.wikipedia. org/wiki/Daigo_Fukury%C5%AB_Maru. Public domain

The military successfully concealed the fact of radiation damage to the inhabitants of the Marshall Islands and personnel. But the Japanese fishing vessel “Dai-go Fukuryu Maru” turned out to be in the affected area. Its name

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means “Lucky Dragon Number Five” in Japanese (Fig. 4.13). Further, we will omit this number (dai-go) in the ship’s name. Fukuryu Maru, on her last voyage, left the port on January 22, 1954, and headed for the tuna fishing area near Midway Atoll. There were many other Japanese anglers in the same area. But then the ship changed its route, broke away from other fishing vessels, and proceeded noticeably south to the Marshall Islands. The sailing route of Fukuryu Maru is shown in Fig. 4.14. On March 1, 1954, early in the morning, it was still dark, the ship was fishing for tuna, and suddenly a bright fire broke out in the west of the ship as if the sun had risen there, in the west, only much brighter than usual. It was at 6:45  am local time that the Bravo thermonuclear charge exploded. The exact position of the vessel is difficult to establish. It is reported that it was located at a distance of about 160 km from the epicenter, outside the restricted zone. Subsequently, Lewis Strauss, chairman of the Atomic Energy Commission, pointing out the ship’s strange rerouting, told US President

Fig. 4.13  Unfortunate “Lucky Dragon” (Daigo Fukuryu Maru). Figure from Daigo Fukuryu Maru, Wikipedia—https://en.wikipedia.org/wiki/Daigo_Fukury%C5%AB_ Maru. Public domain

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Fig. 4.14  The route of the last voyage of the Japanese fishing boat Fukuryu Maru. The box shows the danger zone that was originally set. Already after the explosion, the danger zone was significantly expanded, the new zone is shown with a dotted semicircle. Figure on the basis of the site: The Japanese Fishing Boat Whose Lethal Encounter with An Atomic Bomb Inspired Godzilla. Kaushik Patoway. Amusing Planet, 2019— https://www.amusingplanet.com/2019/07/the-­japanese-­fishing-­boat-­whose-­lethal. html and from Kenji Namba. The hidden truth of Bikini Incident. Hiroshima Peace Media Center, May 7, 2008—https://www.hiroshimapeacemedia.jp/?p=19453

Dwight Eisenhower’s press secretary that the ship might have been a Soviet spy sent to the area specifically to gather information about American tests of thermonuclear weapons. The cloud of explosion products reached the ship a few hours later. The vessel with 23 fishermen was covered with precipitation that resembled snow. The sailors rubbed the flakes with their fingers and tried on the tongue. Soon, the fishermen began to feel sick, skin and eye irritations appeared, the mechanic Yamamoto suddenly almost completely lost his sight. The dust burned the fishermen’s skin in places where it was not protected by clothing. Shortly after the Bikini snowfall, the skin first turned red, then blistered. The sailors, whose heads were left uncovered during the explosion, gradually became bald, and in some places, purulent wounds formed. On the way back, many crew members vomited. They felt terrible weakness. Later, they

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developed a fever. “Bikinsky” disease had an impact on the sex glands. Most of all, the Bikini disease affected the blood (all members of the crew of the Lucky Dragon had a sharp decrease in the number of red blood cells) and kidneys. The skin of the fishermen has noticeably darkened. The ship returned to port only fourteen days later. Although the fishermen complained of serious illness, they were not immediately noticed, and when they did, it was found that the signs of their illness differ markedly from the illnesses of the Japanese who survived the nuclear bombing of Hiroshima and Nagasaki, where people were subjected to short-term direct radiation exposure from the explosion cloud. And for a long time, the fallout products acted on the fishermen. Doses received by fishermen are estimated at 1.7–6  Gy. These doses were received during the 14 days of sailing home, with about half of the dose received during the first day. All 23 fishermen of the Fukuryu Maru got radiation sickness. One of the team members, Lucky Dragon’s oldest radio operator, Aikichi Kuboyama, died 207  days after the explosion at the age of 40. The cause of death is believed to be cirrhosis of the liver. According to Japanese doctors, most of the fishermen had liver problems due to accidental infection with hepatitis C, the infection was introduced during treatment for radiation sickness during a blood transfusion. In addition to health problems, the fishermen were faced with another trouble. Those who received radiation sickness were considered infected; they were shunned and avoided. The fishermen who survived and generally restored their health could not find work. It was difficult for them to get married. Many victims were forced to leave their usual places of residence and move to places where no one knew them. After a year of hospitalization, the rest of the crew, except for the deceased radio operator Aikichi Kuboyama, gradually recovered. Luckily, for the most part, they were all very young, even their captain, Hisakichi Tsutsui, was only 22 years old. The bald sailors’ hair grew again, the abscesses gradually disappeared, the activity of the kidneys improved, and the blood returned to normal. Moreover, although all the fishermen received such large doses that they caused radiation sickness, some lived quite a long life. One of the fishermen, Susumu Misaki, died at the age of 92. After 60 years, in 2014, out of 23 fishermen, seven were still alive, and after another 5 years, in 2019, four more were alive. Matashishi Oishi was 20 years old at the time of the event. It is known that he tried on the tongue a strange substance that fell on the ship. In 1980, he began to make frequent calls for nuclear disarmament, and in 2011 he published a book entitled “The Day the Sun Rising in the West: Happy Dragon and Me.”

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The same feature, a bright light in the west in the early morning, was also noted by the American director Keith Reimink, who released the documentary “Day of the Western Sunrise” in 2018. Radiation hit not only fishermen. So, the worker, who for two months freed the vessel from water, suffered, according to the conclusion of physicians, from the consequences of exposure. Symptoms of radiation damage were also found in the medical workers who cared for the Fukuryu Maru team. Later it turned out that there were about a hundred Japanese fishing boats in the danger zone, which in one way or another were affected by fallout. Studies have shown that tuna caught in the Pacific Ocean at this time turned out to be with an increased level of radioactivity. Many food companies worldwide have stopped accepting fish and fish products from Japan.

4.8 Reaction of the Society The Fukuryū Maru event made a staggering impression on the Japanese and then attracted wide international attention. Alarming reports appeared in Japanese newspapers and news agency releases. “Employees of the lighthouse at Cape Sota, Hyushu Island, who consumed rainwater for drinking, turned out to be poisoned with radioactive substances.” “Masses of radioactive ocean water moving from the equator with the Kuroshivo Current are expected off the coast of Japan in the near future.” “In the area of the explosion, there is a strong radioactive emission from everything that is in the ocean—from the water itself, from fish, from jellyfish, from algae ….” “Tuna and other fish caught in the Pacific Ocean are contaminated with radiation. Eating is life-­ threatening.” “Radioactive radiation,” “radioactive radiation,” “radioactive radiation”… The expression, only ten years ago known only to a narrow circle of specialists, has now become a symbol of a national catastrophe in the minds of many. In Japan, a documentary story “And finally we caught the sun” was released. Renowned historian of science Ralph Lapp wrote the book “The Voyage of the Lucky Dragon.” The documentary “Operation Ivy” played a big role in the spread of radio-­ phobia. It was filmed in 1952 during tests of the Mike nuclear explosion from the Ivy series, the same explosion that practically vaporized the island Elugelab. Initially, the film was intended for domestic use only, but when the world learned about the tests in the Pacific and the Fukuryu Maru event, the US government had to declassify this film and release it to the public. This film is available up to now on Youtube.

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As science journalist David Ropeik writes, the film made a deafening impression. In one place of the film, the fireball of the explosion is shown against the background of Manhattan, from which it becomes clear to the viewer that one thermonuclear charge will destroy a significant part of the city. A huge crater from the explosion and the disappeared island of Elugelab showed the huge destructive power of the new weapon. On the map of Washington, the announcer explained that if the epicenter were in the Capitol area, then the city would be completely destroyed within a radius of 5 km. The public already knew about the consequences of the bombing of the Japanese cities of Hiroshima and Nagasaki, Mike’s explosion, 500 times more powerful, showed that thermonuclear weapons threaten the existence of life on Earth. Within a few days, the film was shown in a dozen countries. The products of the nuclear explosion “Bravo” reached Australia, India, Japan, and even the USA and parts of Europe. The Bravo explosion, prepared as a covert event, quickly became an international event and stimulated calls for a ban on atmospheric testing of thermonuclear weapons. On July 9, 1955, a group of scientists led by Albert Einstein and Bertrand Russell published an open letter called the Russell-Einstein Manifesto, stating: But we now know, especially since the Bikini test, that nuclear bombs can gradually spread destruction over a much wider area than had been supposed. It is stated on very good authority that a bomb can now be manufactured which will be 2500 times as powerful as that which destroyed Hiroshima. Such a bomb, if it exploded near the ground or under water, sends radio-­ active particles into the upper air. They sink gradually and reach the earth’s surface in the form of deadly dust or rain. It was this dust which infected the Japanese fishermen and their catch of fish. No one knows how widely such lethal radioactive particles might be diffused, but the best authorities unanimously say that a war with H-bombs might end the human race.

The veil of secrecy fell, and the world learned about another damaging factor of a nuclear explosion: radiation and radioactive fallout and was really scared. The story of “Fukuryu Maru,” having escaped from under the veil of secrecy, went around the world and began a mass anti-nuclear movement. The period of radio-phobia began.

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4.9 Major Accidents Radiophobia arose as a reaction to really dangerous radiation events: the nuclear bombing of Japanese cities at the end of World War II, radiation sickness and the death of some Japanese fishermen, accidents at nuclear enterprises and nuclear power plants: in Chernobyl on April 26, 1986, and in Fukushima on March 11, 2011, on nuclear submarines, the loss of nuclear bombs and other events, information about which broke through the veils of secrecy. Radiophobia is fed by the special properties of radiation, or, more precisely, the absence of obvious properties—no smell, no taste, no color, an invisible and impalpable enemy seems especially scary. The largest accidents in Chernobyl and Fukushima are described separately and in detail in Sects. 7.6, 7.7, and 8.7.5. And here we will point out several others that also greatly influenced the population’s mood. Some of them became known almost immediately, others were covered with a veil of secrecy, but when the veil fell, these accidents horrified society.

4.9.1 Accident in Windscale (Great Britain) On Thursday, October 10, 1957, a fire broke out at the first reactor of the two-reactor complex for the production of weapons-grade plutonium Windscale in the north-west of England on the coast of the Irish Sea when the graphite masonry was annealed. The fire lasted three days and as a result, a significant amount of radioactive materials escaped into the surrounding space. The location of the Windscale complex on the UK map is shown in Fig. 4.15. The degree of danger of accidental events is usually assessed according to the International Nuclear Event Scale (INES), developed by the International Atomic Energy Agency (IAEA). According to the INES scale, all events are divided into seven levels according to their danger. From level 4, events are called “accidents.” At a lower level, it’s just an incident (levels 3 and 2) or even an anomaly (level 1). The event at Windscale was assigned a Level 5 alert. This level includes events in which a certain release of radioactive substances into the environment occurred with the danger of infecting not only personnel but also the population.

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Fig. 4.15  The Windscale complex on the UK map (here it is designated as Sellafield, why—see text). Figure from File: UK-map.svg—https://commons.wikimedia.org/wiki/ File:Uk-­map.svg. Public domain

The Windscale complex is a huge multifunctional conglomerate with over 200 nuclear facilities. So many nuclear installations are assembled in one place nowhere else in Europe.

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The first signs that something was wrong at the station appeared on Friday morning, October 11, when more than 2000 workers of the complex who went to work returned home, and strict security appeared before entering the territory. Work on overcoming the consequences of the accident was headed by the Deputy General Manager of the station Tom Tuohy. The action was taken immediately. Already on the first day of the fire, all dairy producers from the surrounding farms were informed about the prohibition of the sale and consumption of milk. And when one of the farmers asked why all these pleasant little measures were being taken for them, he received the answer, “Radiation, sir.” Because of the fear that milk produced within 500 km2 could be contaminated with radioactive iodine, over the course of a month, it was diluted with water a thousand times and poured into the Irish Sea. Regarding the discharge into the Irish Sea of both diluted milk and various radioactive waste, Ireland and the Scandinavian countries subsequently made strong protests. In 2001, the Irish government sent a complaint to the UN. In 2003, the British government acknowledged the presence of traces of the radioactive nuclide Technetium-99  in the bodies of salmon caught near Windscale. A detailed report on the event, known as the Penney Report, was ready in two weeks but was classified by order of then British Prime Minister Harold Macmillan. Macmillan feared the political consequences of the accident and the panic of the population. Radio-phobia has already firmly taken over the public mood. The classification of the report was removed only in 1988. No one was evacuated from the adjacent territory. Studies of the health status of plant workers who took part in the clean-up activities, conducted in 2010, showed that no long-term health effects occurred. The accident at Windscale, which is precisely the accident according to the official classification, was not the first event in which radioactive substances escaped from a nuclear facility into the outside world. It’s just that this event is better known and is regularly mentioned in various anti-nuclear materials that inflate radio-phobia. After the much more well-known accident at the American nuclear power plant Three Mile Island in 1979, which is described further, the name Windscale has become in the UK and even more widely in Europe a symbol of the threat to environmentalists and opponents of nuclear energy. In an attempt to get rid of this stigma, British Nuclear Fuels (BNFL) changed the plant’s name to Sellafield in 1981. Although after that the situation remained almost the same. Now, in 2021, the English-language segment of Google gives approximately the same, about a million, number of links to the words Windscale and Sellafield.

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Five years before the accident at Windscale, on December 12, 1952, in the Canadian province of Ontario, an event of the fifth level of danger also occurred in the Chalk River Laboratory (Canada). This event is the world’s first radiation accident in which a partial meltdown of the reactor core occurred, but it did not make such a strong impression as the Windscale accident, and the subsequent events described below.

4.9.2 Radiation Events in Southern Ural (Former USSR) Two weeks before the Windscale accident, on September 29, 1957, in the southern Urals, a much more serious level 6 event, the so-called Kyshtym accident, happened in the USSR.  It happened at plant number 817, now known as the Mayak Production Association, located near the closed city of Ozyorsk. Since both the name of the plant and the name of the city were classified, the accident began to be called “Kyshtymskaya,” after the name of the city closest to Ozersk, marked on the maps, Kyshtym. The release of radioactive substances fell on the territory of the Chelyabinsk and Sverdlovsk regions in a strip 300–350 km long in the northeast direction from the explosion site (in the direction of the wind) and up to 20–40 km wide. The fallout zone formed the so-called East Ural radioactive trace (EURT), shown on the map in Fig. 4.17. A significant part of the EURT territory, up to 10 km wide and about 105 km long, receives the official status of radioactively contaminated. Plant “Mayak” is an enterprise to produce weapons-grade plutonium, its activities were seriously classified; moreover, radiation accidents were kept secret. But it was not possible to completely hide the Kyshtym events. Still, the population of 23 villages from the most polluted areas with a population of up to 12 thousand people had to be relocated. The Mayak enterprise created significant radiation contamination of the area several times. Almost from the very beginning of plutonium production, in 1949, Mayak dumped liquid radioactive waste into the Techa River. The river flows into the Iset, which flows into the Tobol, the Tobol into the Irtysh opposite Tobolsk, the Irtysh flows into the Ob, and the Ob carries its waters with an admixture of radioactive substances into the Arctic Ocean. It was assumed that a sufficient measure to reduce the concentration of radioactive waste would be dissolution in a large amount of river water. This decision was based on the experience of the United States, where radioactive waste from the plutonium production at Hanford in Washington state was dumped into the Columbia River, which was much wider and about a thousand times fuller than the Techa.

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Initially, it was assumed that the water would be cooled in special cooling towers, as is done at many thermal power plants. However, the organizers of the construction of the enterprise and leading physicists, including Kurchatov, while flying around the territory on an airplane, realized that the cooling towers would soar (especially in winter), which would inevitably cause a sharp unmasking of the site from the air. To make the weapons-grade plutonium plant less visible, it was decided to conduct cooling without a cooling tower and drain the water into the river. The river was polluted with radioactive substances at a considerable distance. From the most polluted areas of the river basin, Techa resettled about 8 thousand people. The refusal of cooling towers is because at that time American reconnaissance aircraft flew over the country at high altitudes freely, and USSR did not have fighters and missiles that could interfere with them. Only on May 1, 1960, a Soviet S-75 missile shot down an American U-2 spy plane piloted by Francis Powers near Sverdlovsk, now Yekaterinburg. After that, the flights of American reconnaissance stopped. According to some reports, the discharge of radioactive waste into the reservoirs of the Techa River in small quantities continued in the XXI century. According to the court ruling (on the criminal case against the former director of Mayak, Vitaly Sadovnikov, dated May 11, 2006), during 2001–2004, about 30–40 million cubic meters of radioactive waste were dumped into Techa. Finally, additional pollution was brought by the spread of silt deposits of Lake Karachay. Wastes from nuclear-chemical industries also merged into this drainless lake, and by 2000, about 120 million Ci of radioactive waste, mainly cesium-137 and strontium-90, had accumulated in Lake Karachay. During the low-water period (1962–1967), the water level in the lake dropped significantly, exposing several hectares of its bottom. The wind lifted radioactive deposits from the bottom of the lake and carried them to the surrounding area. For the conservation of Lake Karachay, it was covered with soil and laid with concrete blocks, and, apparently, by the end of 2015, it was completely covered. At least the message appeared in the press “The lake of radioactive waste Karachay was liquidated in the Chelyabinsk region. ... On November 26, 2015, the last square meter was filled up on the reservoir.” The areas of radioactive contamination from the Kyshtym accident, the so-­ called East-Ural Radioactive Trace, are shown on the map in Fig. 4.16. To the south of the Kyshtym trace, adjacent to it, there is a shorter, but wider zone of radioactive sediments from Lake Karachay.

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Fig. 4.16  Approximate scheme of the spread of radioactive contamination of the soil as a result of the activities of the Mayak Production Association. Figure from the website Atlas EURT. History of the Formation of Radioactive Contamination in the Sothern Urals, (in Russian)—http://downloads.igce.ru/publications/Atlas/CD_VURS/7-­12.html. With permission of the Yu. A. Izrael Institute of Global Climate and Ecology

4.9.3 Three-Mile-Island Accident (USA) Let’s give an example of another level 5 event, which, perhaps, most of all influenced the attitude of the public towards nuclear energy. We are talking about the accident at the nuclear power plant Three-Mile-Island on March 28, 1979. The station is located in the densely populated state of Pennsylvania in the eastern United States. Washington is within the 100-mile zone, and New York is within the 200-mile zone. Almost 700 thousand people lived in the 20-mile zone around the nuclear power plant. The main cause of the accident is the loss of reactor cooling due to coolant leakage. As a result of the accident, radioactive fission products were carried out of the reactor vessel,

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into the Susquehanna River, and the air, but the bulk of the radioactive nuclides remained within the building. Information about the accident was leaked to the media, and panic seized the state. The administration announced only voluntary evacuation of pregnant women and preschool children. But over 150 thousand people independently left the 20-mile zone (32 km) around the station. Entire districts have turned into lifeless ghost towns. People returned to their homes only three weeks later. The real contamination of the area around the station turned out to be insignificant, the evacuation occurred due to poor organization, inaccurate information, and the general panic of the population regarding radiation, due to radio-phobia. In subsequent studies, no evidence of an excess of the risk of cancer in the population beyond what was expected was found. I must say that in fact the situation at the reactor was very dangerous, and the United States and the world were lucky that it ended relatively well. But this accident caused an extremely wide resonance in society, and a large-scale anti-nuclear campaign began in the United States, which resulted in a gradual abandonment of the construction of new power units. As a result, the nuclear power industry in the United States has hardly developed since the 1980s. Until 2012, no new licenses for constructing nuclear power plants were issued, and the commissioning of 71 previously planned plants was canceled. There are currently approximately sixty anti-nuclear groups active in the United States, and the damaged power unit has not been operating since then and is under constant surveillance. It took about 14 years to clean it up alone, at a cost of nearly one billion dollars. Let us sum up the results of radiation events, which especially influenced anti-nuclear sentiments in the world. For all the years of using nuclear energy, six events of the fifth level occurred. We named three here—the Chalk River, Windscale, and Three Mile Island. One—the 6th—the Kyshtym accident, and two events of the largest, seventh level of danger—Chernobyl and Fukushima. Let us point out the three accidents of the fifth level not mentioned above— these are two accidents in the USA (July 26, 1959, in the Santa Suzanne laboratory in California, near Los Angeles, and January 3, 1961, at the SL-1 experimental reactor located at the nuclear reactor test station in Idaho), as well as the accident in the USSR in the Chazhma Bay in the Far East on August 10, 1985, which occurred during the reloading of nuclear fuel from the reactor on the K-431 nuclear submarine. There were other events recorded by the International Atomic Energy Agency. Most of these events did not lead to human casualties and the release

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of radiation outside the reactor rooms and did not attract the general public’s attention. Others, although they were very serious accidents with a significant spread of radioactive materials in the environment but occurred far from the center or even in sparsely populated areas, information about these accidents was more or less successfully hidden. And the relatively minor events, if reported, but mainly the much more dangerous and much more widely known accidents at Chernobyl and Fukushima, fed the already existing radio-phobia among the population and led to a significant slowdown in the development of nuclear energy and even to a recession. Some countries in Western Europe, such as Sweden, Germany, Spain, Belgium, and Holland, have legally abandoned their earlier plans to use nuclear energy. However, today, in these countries, nuclear energy makes a significant contribution to the production of electricity. The situation with nuclear power plants in Germany is described in the Introduction. This year (2022), if nothing changes in the plans, the last power reactors will be shut down. At present (spring 2023), there is no complete clarity on the future of nuclear energy, but it is quite likely that a renaissance is possible, a new take-­ off of this energy industry. Energy is needed and the possibilities to meet its demand with new, so-called renewable energy sources, are still poorly realized. Meanwhile, nuclear scientists continue to work. The foundations for the creation of generation III+ high-safety nuclear reactors have been laid, extensive experience has been gained in the control and isolation of radioactive waste, the technology of a closed nuclear fuel cycle has been developed, experience has been gained in creating breeder reactors, and there are other indisputable achievements. All this increases the efficiency and competitiveness of nuclear power. Therefore, the above situation reflects only today, we will follow how it will develop in the future.

4.10 Horror Films A huge role in the spread of radio-phobia was played by catastrophe films of the Cold War, the so-called horror films, which paint apocalyptic pictures of general or local nuclear disasters. In the list of films about nuclear annihilation (about nuclear massacre), the first films date back to 1951. But, apparently, the real parade of films—nuclear horrors began with the black-and-white drama film “Godzilla,” which appeared in Japan in 1954. The film is to some extent inspired by the event with Fukuryu Maru. In the film, scientists and

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politicians are faced with the sudden appearance of a huge monster from the depths of the ocean, which they called Godzilla (Fig. 4.17). In 1956, an Americanized version of Godzilla appeared under the name “Godzilla. King of the Monsters.” A whole series of similar films followed it, the last of them to date, also called “Godzilla,” which was released by Warner Bros. in 2014. The Godzilla movie launched a whole genre of films about mutants created by radiation, which went for a walk on the screens of cinemas, books, and television programs and tickled the nerves of viewers and readers. Dozens, if not hundreds, of these films have been released in the USA. Such films were shot in other countries as well. We will name only the most talented and appeared earlier than others. These are the films “On the Shore” directed by Stanley Kramer, in 1959 and the film “Dr. Strangeglove” directed by Stanley Kubrick, in 1964. A poignant film on this subject was shot by the French director Alain Resnais “Hiroshima, my love” (Hiroshima mon amour),

Fig. 4.17  Godzilla as portrayed via suitmation in Godzilla (1954). Figure from Godzilla, Wikipedia—https://en.wikipedia.org/wiki/Godzilla. Public domain. Author: Toho Company Ltd.—Scan of the original photograph. Date: 1954

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1959. One of the most disturbing of films ever made on this topic, film critics call the English film “Threads,” 1984. So, there were a lot of horror films, and there were also television programs, books—novels, stories, short stories, computer games, and much more, designed to tickle the nerves with descriptions of nuclear nightmares. After Chernobyl, additional pushes for the spread of radio-phobia were no longer required. The activities of the “greens” significantly influenced the world’s attitude towards nuclear energy. The main targets of the anti-nuclear movement were nuclear weapons and nuclear power. Protests against these sources of danger naturally shift negative attitudes towards both nuclear technology and the use of ionizing radiation in general.

4.11 The Modern Manifestation of Radiophobia Radiation events are constantly taking place in the world. Radioactive sources are lost, stolen, and thrown away, they are found by random people, dismantle, they change hands, people receive significant doses, get sick and die. There are known cases of the use of radioactive sources for murder and suicide, for abortion, and other, sometimes funny, and sometimes tragic cases. There are few such events, the vast majority of them have been studied and described in detail, but usually little known to the general public. Here we describe some of the most recent events that did not lead to serious consequences for the population. However, one of them ended very sadly for the participants but aroused wide public attention and contributed to the spread and strengthening of radiophobia.

4.11.1 Transportation of Uranium Ore and Depleted Uranium Hexafluoride, 2019–2022 In 2019, the transportation of uranium to Germany and uranium ore processing waste to Russia resumed. This transportation did not stop during the coronavirus pandemic and the war in Ukraine. On Sunday, September 11, 2022, the cargo vessel Mikhail Dudin arrives in the port of Rotterdam; a ship carrying Russian uranium. It will be transferred to trucks transporting it across the Netherlands on Monday to Lingen, Germany, where the uranium will be processed into fuel rods.

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On the way back, Mikhail Dudin usually carries 600 tons of depleted uranium hexafluoride in 80 containers. “Dangerous” cargo from Urenco’s facilities in Gronau, Germany, arrives at the Russian port of Ust-Luga near St. Petersburg, is reloaded into wagons, and sent on a 2500 km journey to the Closed Administrative Territorial Unit of Novouralsk (Sverdlovsk Region). Under the contract, 12,000 tons of uranium hexafluoride (UF6)—chemically aggressive radioactive material—may be transferred from Germany to Russia by 2022. These transportations caused and continue to cause active protests. The movement of these materials across Europe, from Gronau to Amsterdam, was accompanied by demonstrations by environmental activists and Greenpeace actions. In connection with the arrival of these substances in Russia, frightening materials are published in the press, environmentalists initiate actions, deputies send requests, etc. Public Council of the South Coast of the Gulf of Finland released Public Appeal to Angela Merkel, Chancellor of Germany, and Vladimir Putin, President of the Russian Federation. The appeal to the authorities of Russia and Germany was signed by 47 national, regional, and municipal non-governmental associations of Russia, Germany, and the Netherlands. The appeal is signed by regional and municipal deputies of the nuclear regions of Russia, as well as by experts and citizens. Russian-German coalition demands to stop the nuclear waste movement from Germany to Russia under the slogan “Russia is not a nuclear waste dump”! As you know, the radiation hazard of uranium hexafluoride, especially depleted, is negligible, but the chemical hazard is much greater, of course, only if the containers are depressurized. On the other hand, huge quantities of all sorts of dangerous chemicals, explosive ammonium nitrate, sulfuric acid, and many others are transported around the world, but there are either no protests about this at all, or they are much weaker. But the transportation of uranium processing waste excites society. It can’t be helped, radiophobia, sir.

4.11.2 Nuclear Repository in Moscow, Summer-Autumn 2019 In the summer and autumn of 2019, the situation around radioactive burial sites on the banks of the Moscow River, behind the fence of the Polymetal plant near the Zamoskvorechye station of the Kursk railway, unfolded in Moscow. Newspaper and Internet noise rose because the South-Western Chord highway should pass nearby.

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In the 1950s and 1960s, the Polymetals plant, which is now owned by the state corporation Rosatom, stored uranium and thorium ore waste on the steep bank of the Moscow River. The radiation on this slope has been known for many years. In 2004, the New  York Times published an article about radioactive Moscow. The text mentioned a plant on the Kashirskoye Highway. In 2006, Alexander Barinov, the chief engineer of the Radon enterprise for the disposal of radioactive waste and environmental protection, reported that pollution was measured in tens of thousands of tons of radioactive earth. Greenpeace recorded an excess of radiation near the Kolomenskoye park back in 2011. At the end of April 2019, the Radon enterprise and the Ministry of Emergency Situations conducted a certified inspection on the slope. The highest result they found was ~60 μSv/h, while the usual background is about 0.2 μSv/h. Greenpeace experts involved in radiological research say that in the studied areas around the Polymetal Plant, the radiation background reaches 6–8 μSv/h. In some reports, even higher values are given—up to 20 μSv/h. According to experts, about 60 thousand cubic meters of radioactive soil dumps are stored in the construction area. About 450 cubic meters were taken out—less than 1% of the total volume of the repository. Residents of nearby houses, eco-activists, and other caring Muscovites set up round-the-clock duty, trying to prevent the continuation of work, but in vain. In August 2021, a message appeared in the press: Moscow Mayor Sergei Sobyanin launched traffic on a new road passing through the contaminated area.

4.11.3 Explosion near Severodvinsk in Nyonoksa, August 8, 2019 During the tests of new equipment, which took place in the area of the Nyonoksa missile range of the Russian Navy in the Arkhangelsk region, an explosion occurred, or, as it is customary to put it elegantly in such cases, an emergency situation arose. Seven people died, and at least twelve of the victims received high doses of radiation. It is reported that during the transportation, two victims died from the consequences of acute radiation sickness. In Severodvinsk, located 30 km from this place, a short-term increase in the radiation background up to 2 μSv/h was recorded, while the usual level was 0.11 μSv/h. An increase in the radiation background was observed both in Arkhangelsk and in the Murmansk region.

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What exactly happened in Nyonoksa is still unknown. In such cases, it is necessary to specify the date, but here you can do without it—it will always be unknown. It is difficult to assess the degree of radiation hazard since the composition of the emitted nuclides is not known. The secrecy of information about the incident, untimely notification, and subsequent actions of the authorities in the first days after the accident caused various threatening and even panic comments in social networks and some media, up to an analogy with the radiation accident at the Chernobyl nuclear power plant. Local residents began to buy iodine preparations massively. Navigation was banned in the area of the explosion. Part of the radioactive substances released into the atmosphere during the explosion was recorded by Russian meteorological stations, but not by all. On August 10, two days after the emergency, the radionuclide monitoring stations in Dubna and Kirov stopped transmitting data to the International Monitoring System. On August 13, information from some other stations ceased to arrive. The authorities gave conflicting explanations for interrupting data transmission, which further contributed to spreading panic rumors and sentiments and fueled radiophobia.

4.11.4 Ruthenium-106 Release at Mayak, Late September 2017 At the end of September 2017, reports appeared in French and German newspapers about the release of ruthenium-106, which apparently occurred in the south of the Urals. This event became known to the general Russian public only at the end of November. The French Institute for Nuclear and Radiation Safety (IRSN) estimated that the release was 100–300 terabecquerels (million million). Official information about this event was completely contradictory. First, Roshydromet (The Russian Federal Service for Hydrometeorology and Environmental Monitoring) provides information on exceeding the level of ruthenium-106 at several posts in Russia. Then Rosatom reports that no ruthenium-106 has been found in Russia, except for a single measurement point in St. Petersburg, and that at the enterprises of Rosatom, radioactivity is within the normal range and corresponds to the natural radiation background. But excess ruthenium-­ 106 is found in samples taken by the Ural Department of Hydrometeorological Service. The actual values of the dose rate from ruthenium-106 in this event are much less than the maximum permissible values, there is no need to talk

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about any evacuation, even from the most contaminated places, but, as you know, the fallout of radioactive substances can be very uneven, and careful monitoring in infected areas is needed.

4.11.5 Radioactive Rocks in the Grand Canyon, USA, February 2019 The American media AzCebtral reported that containers with radioactive stones were found somewhere near the spectator platform in the Grand Canyon, USA.  The panic message reads, “For about two decades, tourists with children and employees of the world-famous Grand Canyon National Park have been exposed to high radiation levels.” It is talking about three buckets with stones, which are considered samples of uranium ore. From 2000 to 2018, they were kept in the museum building, which was visited by tourists, students, and museum staff. The U.S.  Occupational Safety and Health Administration and the Arizona State Bureau of Radiation Control joined the situation discussion. Experts believe that the original dose rate determinations were erroneously exaggerated by a factor of 1000. The stones were removed from the museum back in June 2018, but the empty buckets were returned to the museum, and only in February 2019, a scandal erupted. This case is a perfect example of radiophobia.

4.11.6 Swear Word = 1000 Röntgen Another manifestation of radiophobia is the comparison of something unpleasant with the action of radiation. Roskomnadzor (Federal Service for Supervision of Communications, Information Technology and Mass Media in Russian Federation) published the results of a study of the work of Russian rapper Yegor Creed, in his songs they found “anti-values of Satanism.” In particular, the conclusion states, “It has been proven that a swear word causes a mutagenic effect similar to radiation with a power of thousands of roentgens.” True, a message soon appeared that on November 18, 2019, Roskomnadzor suspended for 120 days the validity of accreditation certificates for specialists who conducted an examination of Yegor Creed’s songs. Fools were slightly restrained, but the conclusion itself is symptomatic.

5 The Effect of Radiation on a Living Organism, View from Outside

In this book, the author sets himself to prove that radio-phobia is an unreasonable and harmful fear. Let us repeat the main statement of the book once more. Large doses of radiation are dangerous, but the probability of getting them is much less than the probability of catching a dangerous virus, being a victim of a car accident, or having bad habits (smoking, alcohol, drugs). Small doses are not only safe but also useful and necessary. The rest of the book will demonstrate experimental and observational data substantiating and confirming this idea. First, in this chapter and Chap. 6, we will describe how radiation affects living tissues and how this effect is studied. In subsequent chapters, we will present evidence for the favorable properties of low doses of radiation, namely that they are safe (Chap. 7), useful (Chaps. 8 and 9), and necessary (Chap. 10). From these chapters, readers will see that the listed properties of low doses of radiation not only have reliable experimental confirmation but also rely on certain molecular mechanisms responsible for these properties.

5.1 What Is “Dose” and What Is “Effect” Let’s start with an outside analysis of the manifestation of the effects of radiation on the body. Provide a so-called macroscopic approach, a view from above. Radiation is dropped on an organism, its action is characterized by a “dose” that can be measured, and there is the result of radiation exposure, i.e., some “effect,” which can also be characterized in one way or another without delving into the microscopic picture of the processes occurring in cells. Here we © The Author(s), under exclusive license to Springer Nature Switzerland AG 2023 I. Obodovskiy, From Radio-phobia to Radio-euphoria, Springer Praxis Books, https://doi.org/10.1007/978-3-031-42645-2_5

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discuss the connection of the result of the impact, i.e., effect, and doses. A microscopic picture of the interaction of radiation with a living cell and the consequences of this interaction, i.e., molecular and cellular processes are discussed in Chap. 6. Before analyzing the dose-effect relationship, let’s clarify the concepts included in this relationship, and explain what a “dose” is and what an “effect” is.

5.1.1 What Is “Dose” The action of radiation on a living cell is determined by a quantity called “absorbed dose.” It is equal to the energy of radiation absorbed in a unit mass of matter, i.e., the energy that ionizing particles spend on ionizing atoms and molecules of a substance. In the tasks that we are considering here—on the ionization of molecules of living cells. More detailed information about ionizing radiation, its types, and its properties one can find in the Appendix. An absorbed dose is a physical quantity that a real device can measure. The absorbed dose is measured in units of joule/kg, which have a special name gray (Gy), named after the English physicist, one of the founders of radiobiology, Lewis Harold Gray (1905–1965). The action of radiation is determined not only by the energy of the particles but also by how this energy is distributed along the path of the particle. A quantitative measure of this distribution is a quantity called Linear Energy Transfer (LET). This value is described in more detail in the Appendix, but already here it must be said that all radiations can be roughly divided into two groups: weakly ionizing, with a small LET value, and strongly ionizing, with a large LET value. The same doses of radiation with different LET give different effects. Particles with a larger LET create a larger lesion at an equal dose, i.e., radiations with different LET have different biological effectiveness. This circumstance for a long time was characterized by the so-called quality factor (Q). Quality Factor reflects the ability of a certain type of radiation to damage body tissues. A rather strange name, since this coefficient is the greater, the more dangerous the radiation, i.e., the coefficient reflects the quality of the harm. Currently, “Radiation Weighting Factor,” wR is used instead of a quality factor. The wR values are given in the Appendix. To correctly account for the effects of various types of radiation, the concept of “equivalent dose” is introduced. The equivalent dose is equal to the product of the absorbed dose and the Radiation Weighting Factor. Equivalent

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doses are measured in units called sievert (Sv), named after the Swedish radiobiologist, one of the founders of radiobiology, Rolf Maximilian Sievert (1896–1966). For weakly ionizing radiation (X-ray and gamma quanta), the Radiation Weighting Factor is equal to one. This means that the absorbed dose, measured in grays, and the equivalent dose, measured in sieverts, are numerically equal. For highly ionizing radiation (alpha particles), wR is 20. The equivalent dose cannot be measured with a physical device, it can only be calculated if the composition and spectrum of the irradiating particles are known. However, one can try to solve the inverse problem, to determine the dose from the biological effect, if the relationship between dose and effect has been previously established. This is done by “biological dosimetry” for certain biological markers. For more details on the types of ionizing radiation and the features of their effect on a substance, see the Appendix. There one can also find the units of dose measurement, the ratio between units, and the values of the Radiation Weighting Factor.

5.1.2 What Is “Dose Rate” The dose determines the effect of radiation during short-term exposure. So, for example, during the nuclear bombardment of the Japanese cities of Hiroshima and Nagasaki, the main effect of radiation lasted less than a minute. However, in many cases, radiation affects people for a long time and, perhaps, much more often than for a short time. The entire population is continuously exposed to the radiation background, both natural and so-called anthropogenic, resulting from human activity. For a long time, the workers of various nuclear enterprises have been affected by the radiation they work with. In this case, the “dose rate” parameter should be used, i.e., dose per unit of time. The dose rate determines the rate of dose accumulation and is measured in dose/time units, such as microsievert per hour—μSv/h. It should be noted that sometimes the dose rate is given in units not per hour, but per year, for example, millisievert per year—mSv/year. The exact relationship between the various units is given in the Appendix, roughly, it can be considered that 1 mSv/year ~0.1 μSv/h. With the transition from dose per hour to dose per year, one should be careful. Such a transition can only be carried out for stable exposure conditions, because radioactive sources decay over time, and exposure conditions could change.

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5.1.3 What Is “Effect” Now about what the effect is in the “dose-effect” relationship. When studying the dose-response relationship, one has to use two options for determining the effect: the actual lesion or the probability of lesion. At high irradiation doses of the whole organism, greater than a certain limit value, a special form of damage to tissues, organs, and the whole organism develops, unknown before starting work with high radiation intensities— “radiation sickness.” It is important that the effects of exposure, in this case, can be observed directly—this is an increase in body temperature, the frequency of the urge to vomit, bleeding, etc. In the region of lower doses, which are now commonly called “medium” doses, below a certain threshold, no clinically detectable effects of exposure are observed, but adverse effects are possible after a considerable time, the so-­ called long-term effects, which appear years and decades after irradiation. In this case, the “effect” is the probability of injury, as measured by the proportion of people who get sick or die, and indicators of the risk of getting sick or dying. The boundary between large and medium doses is not very clear. At doses from the region of medium doses, near the limit value for radiation sickness, or even at larger ones, but absorbed by individual parts of the body, observed effects appear, but they are no longer attributed to radiation sickness and are called radiation injury or radiation trauma. In this case, the effect of radiation is manifested in the data of laboratory tests, for example, a decrease in the concentration of leukocytes, erythrocytes, and other blood components, an increase in the number of chromosomal aberrations, the total number of microbial bodies and endotoxins, etc., and in this case, the effect is the result of real measurements.

5.2 Dependence “Dose–Effect” To describe the dose-effect relationship, we divide the dose scale into three areas. We will indicate the boundaries of these areas in Sect. 6.7. At “large doses” in the body there are lesions, radiation sickness, or radiation injury, the severity of which more or less clearly depends on the dose. Such a dose-response relationship has long been called “deterministic,” i.e., the effect was causally related to the dose. However, the International Commission on Radiation Protection (ICRP) currently recommends the use

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of a different term, “tissue reactions.” Indeed, we are talking about effects that actually manifest themselves at the level of body tissues. However, the Commission does not mind if these two terms are used as synonyms. Since the book is devoted to low doses, we will not talk more about radiation injuries of any severity. Doses at which only long-term effects are observed and no measurable damage can be detected are classified as “medium doses.” A characteristic feature of long-term consequences is the probabilistic nature of the upcoming damage. Such effects are called “stochastic,” i.e., random or probabilistic. The severity of the resulting consequences does not depend on the dose, it is the probability of the consequences that depends on the dose, and the long-term consequence itself is almost always the same—cancer. As American scientist William Hendee determined this situation: “A stochastic effect is an ‘all or none’ response.” True, in addition to cancer, other long-term consequences are also possible: physiological disorders (disruption of the thyroid gland, etc.), cardiovascular diseases, allergies, chronic respiratory diseases, immunodeficiency, and the associated increase in the body’s sensitivity to pathogens of infectious diseases, temporary or permanent sterility. Of particular note is the damage to the cell fibers that make up the lens, and as a result, clouding of the lens (cataract). However, the likelihood of other long-term effects is much less than the likelihood of cancer, and the consequences, as a rule, are not so fatal. The probabilistic nature of the lesion is manifested in the fact that some people exposed to ionizing radiation develop cancer, and some do not, but, in principle, cancer can occur without any impact. Thus, cancer is not a necessary consequence of radiation exposure, and radiation is not necessary for the occurrence of cancer. The relationship between radiation exposure and cancer turns out to be probabilistic, statistical. The dose determines the likelihood of cancer, not the severity of the lesion. Therefore, the result of exposure to radiation in any selected group of people is expressed in random numbers. Finally, in the third area, in the area of “low doses,” long-term effects on the scale of the duration of human life do not occur. Irradiation is, but there are no dangerous consequences. This is the area of doses that this book is devoted to. How the impact on a person of low doses from this third area manifests itself is described in Chaps. 7–10. Note that there are no dangerous consequences, lesions, or diseases, but the body’s reaction to low doses is, as a rule, a positive reaction. In recognizing the beneficial effect of radiation in low doses, we are still at the beginning of the path, we have not yet learned how

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to measure it. Therefore, it is shown conditionally on the graphs. For more on the manifestation of positive effects, see Chap. 8. The note on the time scale of the occurrence of long-term consequences is not accidental. Since the main long-term consequence of cancer is a long latent period, one might think that there should also be long-term consequences in this case, but usually people do not live up to these consequences. However, the data available to date show that at low doses, in fact, the risk of cancer at any life expectancy is negligible. See Sect. 6.4 for more on the relationship of cancer with age. The listed dose areas are shown in the graph in Fig. 5.1. The upper graph shows the dose-response relationship in the high-dose region. This dependence has a threshold, typical numerical values of the threshold dose are given in Sects. 6.7 and 6.8. Usually, in the initial part of the graph, the severity of the lesion increases slowly with increasing dose, which reflects the body’s 1 0,9

Leision severity

0,8 0,7 0,6 0,5 0,4 0,3 0,2 0,1 0 0,5 Probability

0,4 0,3 0,2 0,1 0 0,1

1

10

Dose, Gy

Fig. 5.1  Dose-effect relationship. The upper graph is the area of tissue effects, with an increase in the dose, the severity of the lesion increases. The lower graph is the area of stochastic effects. With increasing dose, the probability of damage increases

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ability to withstand the damaging effects of radiation. Then the slope of the curve increases, the dependence becomes almost linear, and with a further increase in the dose, the increase in the severity of the lesion slows down and, in the end, the curve reaches saturation. Indeed, any parameter by which we describe the damage to the body has certain limits. Body temperature cannot rise above 42–43 °C, the concentration of leukocytes cannot be below zero, etc. Thus, dose-response curves resemble the Latin letter S, they are called S-shaped, or sigmoid dependencies. The presence of the threshold of the deterministic curve is established quite reliably and does not raise doubts. Stochastic dependence has approximately the same form as the deterministic one and also has a threshold, below which no effects are observed. The region of low doses is located below this threshold. The question of the presence of this threshold is being intensively researched and discussed in heated discussions and sometimes desperate struggles at the present time. Similarly, this threshold is discussed further in Sect. 6.7. We draw your attention to the fact that long-term effects in the form of cancer can also manifest themselves in the area of high doses, up to death. Moreover, even with a lethal dose due to radiation of 5 Sv, the probability of death from cancer is approximately 25%. This is shown in Fig. 5.1. Radiation is a weak carcinogen, much weaker than many chemicals. Let us also consider such a situation when, after irradiation, some kind of disease has arisen, but there is no connection with the dose. People who received significantly different doses suffer the same disease or with the same probability. This may mean that radiation was not the cause of the disease. Theoretically, in addition to the so-called somatic long-term consequences that develop in the irradiated individuals themselves, there could also be genetic, hereditary diseases that develop in the offspring of irradiated parents. However, in more than 70 years of research on human populations (beginning with the study of people affected by the atomic bombings in Japan), it was not possible to identify distinct hereditary effects of radiation exposure. In other words, unexposed children of exposed parents showed no increase in cancers, deformities, and abnormalities compared to control families with unexposed parents. This fact is firmly fixed in the documents of authoritative international organizations. Once again, we will clarify that we are talking about parents irradiated before the conception of a child. Irradiation of the fetus, even in small doses, can lead to undesirable consequences. However, hereditary effects of irradiation that could not be identified in humans have been found in animals, particularly in the famous Mega-mouse project with a colossal number of animals used—a total of 7 million mice. The research was conducted by a team of scientists from Oak Ridge, led by the

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spouses William and Lian Russell. It was perhaps the largest biological experiment conducted at a single institute. For a long time, the research group occupied all three floors of a huge building called the Mouse House. It had 66 rooms with mice, which simultaneously contained more than 250 thousand animals. Only in an experiment of this magnitude was it possible to reliably prove the existence of hereditary effects of irradiation in animals. Since all living organisms, at least vertebrates, have similar biological bases, the result of the mouse experiment, it would seem, gives reason to believe that a person may also have risks of hereditary effects of radiation. However, extremely low, which in principle could be revealed only in groups of hundreds of thousands of offspring of irradiated parents. Note that the doses in the Mega-mouse project were quite large (from 6 Gy of X-ray radiation). However, the conclusion that follows from the results of the Russells about the magnitude of the hereditary effects of irradiation in humans is subject to reasonable doubt in an article by one of the Russells’ employees. In 1994, Dr. Paul Selby, who participated in the processing of the results of measurements in the Mega-mouse experiment, found that there were some errors in the published results of the Russells and that the hereditary risk of radiation in humans was probably overestimated by at least ten times.

5.3 How the Dose-Response Relationship Is Measured Of course, the best way to measure the effects of radiation is experiment, i.e., human-organized research. The most reliable information could be obtained in experiments on humans. The problem of medical experiments on humans contains a certain contradiction. On the one hand, experiments that pose a danger to people are ethically vicious, inhumane, and unacceptable. On the other hand, we have to admit that they are necessary. Apparently, such experiments began to be carried out in ancient times. The history of numerous experiments of doctors on themselves is described in detail, for example, in the book by Austrian physician and public figure, popularizer of science Hugo Glazer “Dramatic Medicine. Self-experiments by physicians” (Dramatische Medizin. Selbstversuche von Ärzten). Physicians experimented not only on themselves, but also on volunteers or, more often, on patients. Moreover, patients often did not know that they were becoming

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research participants. Clinical drug trials are a necessary step in developing any new drug. Until the middle of the XX century, the rights of participants in clinical trials were not defined and protected in any way. Public opinion and regulators first paid close attention to human experiments after World War II. At the Nuremberg trials of the leaders of the fascist Reich, the terrible details of the activities of Nazi doctors began to emerge. Later it became known that doctors performed the same kind of villainous experiments in Japan. As a result, a set of rules was developed that define the rights and obligations of all experiment participants, called the “Nuremberg Code.” It was accepted in 1947. The provisions of the Nuremberg Code were clarified in the Helsinki Declaration by the World Medical Association (WMA) in 1964. The Declaration of Helsinki formed the basis of all subsequent recommendations and regulations that define the human rights and ethical obligations of physicians in clinical trials. Clinical trials must be conducted by the fundamental ethical principles of the Declaration of Helsinki Good Clinical Practice (GCP) Rules and applicable regulatory requirements. The most important provisions of modern rules for conducting experiments on humans are the absence of threats to life and health, with the hope that the experiments will not only bring new knowledge but also alleviate suffering or even save lives. Another important provision is informing the experiment participants and obtaining their consent. Let us return from general provisions to the specific question of radiation experiments. When science reliably proves, and society agrees that small doses of radiation are safe, then radiation experiments on people would become possible with their consent. In the meantime, studies of the effect of radiation on people’s health are being carried out on groups of professionals working with radiation and on the population, which, for various reasons, have been forced to accumulate during the acquaintance of mankind with ionizing radiation. In this case, so-­ called observational epidemiological studies are carried out.

5.4 Basics of the Epidemiological Method When small doses of radiation act on the body, it is difficult to identify the relationship between its action and the specific pathology of a particular patient. We have already written that cancer does not occur in all those exposed to ionizing radiation, but cancer also happens without any influence,

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i.e., spontaneously. It is required to separate cancer caused by radiation from spontaneous cancer. At the same time, radiation is known to be a relatively weak carcinogen; at low doses, the proportion of people who fall ill, even those who get fatal cancer, is relatively small. The situation is complicated due to the peculiarity of cancer—the disease occurs after a long latent period. In addition, the result of radiation exposure can be affected by many additional factors, including lifestyle, diet, age, smoking, exposure to environmental chemicals, some of which are carcinogens, and much more. The so-called epidemiological method of research, when a statistical approach is applied to large groups of the population, makes it possible to identify the relationship of causes and effects with such a complex relationship between radiation and disease. Epidemiology originated and proved itself in the process of combating infectious diseases, smallpox, plague, and cholera. At present, epidemiology is also successfully used in the analysis of radiation injuries. The main principle of epidemiological studies is to compare the frequency of a particular disease among people exposed to a damaging factor and people who have not been in contact with this factor. If the frequencies of diseases are close, then this gives reason to believe that the factor under study is not the cause of the disease. If the frequency of diseases in the group of persons exposed to the factor is noticeably higher than in the group of persons not exposed, then this factor may be the cause of the disease. If the disease frequency in the study group is less than in the control group, then the factor is said to have a protective effect. The vast arsenal of a branch of science called “clinical epidemiology” or, more broadly, “evidence-based medicine” is usually involved to quantify such an impact. The meanings of the words “more,” “less,” and others in this context are determined by the rules of statistics. Based on the results of epidemiological studies, a parameter that characterizes the danger of exposure is “risk.”

5.4.1 Risk Calculation Usually, risk is understood as the probability of possible adverse consequences of any action or situation, but in the issues considered in this book, risk is a quantitative measure of the likelihood of adverse factors affecting the body. In the real world, observational epidemiological studies are usually used. They are called observational because the role of the researcher is to observe

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the effects of radiation on people that have already occurred or are occurring and their consequences. The main problem of observational studies is that the observed groups of patients may differ not only in that radiation acts more strongly on some and weaker on others, but also in a large number of other factors, such as age, gender, lifestyle, income level, health conditions, attitude to work, smoking, alcohol and many other, almost immeasurable factors. Therefore, it is rather difficult to identify the role of radiation itself. Observational studies can be organized in several different ways or, as epidemiologists say, with different designs. Here we will name the two most common methods—cohort studies and case-control studies. In epidemiological studies, to name a group of people exposed to a damaging factor, experts use the term—“cohort.” In a cohort study, two groups (cohorts) of people are selected: one exposed and the other unexposed. In each group, sick and healthy people are identified. By this order of work, cohort studies can be retrospective, when the situation with already occurring exposure and identified diseases are analyzed, and prospective, when the researcher starts the analysis either from the very beginning of exposure, or in the process, but even before the manifestation of overt diseases. In the case-control variant, first a group of sick (case) and healthy (control) is selected, and then the proportions of exposed and unexposed among healthy and sick are determined. It is clear that the case-control study can only be retrospective. It is possible to identify the diseased only after they got sick. In both designs, based on the results obtained from the observations, quantitative indicators of risk are calculated.

5.4.2 On Animal Research Animal studies can be performed as an experiment. In this case, a strict protocol is developed for testing. Typically, the test protocol is standard and approved by the relevant authorized organizations, which makes it possible to compare the results obtained in different laboratories. In experiments, it is possible to select a homogeneous group of experimental animals and an exactly corresponding control group. You can provide strictly the same conditions for the experimental and control groups. You can set a certain mode of exposure to radiation of a certain type. Depending on the task, the method of exposure to radiation on the body is selected—acute or chronic. If a study is being carried out on the effects of internal exposure (exposure to the so-called

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incorporated radionuclides), then the type of nuclide, its chemical state, and the method of introduction into the body during the study (with food, by breathing, by application to the skin or injections) is selected. You can have several experimental groups and set certain dose values. Dose levels and intervals between them should be chosen to establish a dose-­ response relationship. The requirements of the statistical provision of experiments determine the number of animals in each irradiated and in the control groups. In general, all conceivable measures are taken to set up the experiment and process its results correctly. In this case, the experiment gives reliable results. In the long-term, they are called chronic, experiments animals are kept in special boxes. The temperature in the experimental room for animals should be 22 ± 3 °С, humidity 50–60%. Lighting should be artificial in the sequence of 12 hours of light, and 12 hours of darkness. Sanitary and hygienic treatment of the boxes is carried out regularly, at least three times a week. During the entire test period, animals are examined daily, food and drink intake is monitored, and weighing is carried out at least once a week. At the end of the test period, the animals are slaughtered, a complete histopathological examination of organs and tissues is carried out, and all tumors are also subjected to a detailed microscopic examination. So, it is obvious that experiments on animals, even on small rodents, require the work of qualified personnel, a long time and, according to estimates at the end of the XX century, cost millions of dollars for each study. Certain difficulties in conducting experiments on animals are created by activists of various societies for the protection of animals. In addition, data obtained in experiments on animals can be transferred to humans with certain reservations. A common problem in determining the effect of low doses is that in animals, as in humans, spontaneous disease is possible without any intentional exposure. As the dose decreases, the probability of damage decreases and may become close in value to the probability of spontaneous disease. In this case, to establish a more or less reliable connection, a large number of experimental animals is required. The more, the lower the dose and the higher the frequency of spontaneous cancer. So, for example, according to the calculations of the experts of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), with a high incidence of spontaneous cancer and relatively low sensitivity to radiation, even at a dose of 100 mGy, a noticeable increase in the probability of cancer induction can be detected only in a group of animals of at least 100,000 individuals.

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Researchers tried to advance into the field of low doses as far as experimental techniques and statistics allowed them. In the published data, typical values of the lower limit of dose dependencies are ~100–200  mGy. In a very small number of works, it was possible to advance in the region of low doses up to ~10 mGy. However, in the history of radiobiological research, the work already mentioned above is known under the name “Megamouse” with seven million animals. The complexity of experiments on mammals described above stimulated the use of non-traditional animal objects with high sensitivity to carcinogenic effects and a fairly short period of tumor development, for example, in aquarium fishes and some insects. It turns out that tumors are formed even in fish and drosophila. Experiments on bacteria, plants, and animals are very useful for understanding the biology of the effect of radiation on living cells, but reliable information about the effect of radiation on humans can only be obtained by studying the effect of radiation on people.

5.4.3 On Human Studies So, from what is written above about the required number of experimental animals, it can be seen that the number of objects depends on the ratio of the frequency of spontaneous cancer and sensitivity to radiation. The same considerations apply to human studies. For known values of these parameters in humans, UNSCEAR calculations show that to obtain a statistically significant (with 90% probability) dose-response relationship in carcinogenesis, one needs to use the numbers of subjects shown in Fig. 5.2. One needs to consider that, in addition to the subjects, approximately the same number is needed for control. Currently, the upper limit of the low-dose region, beyond which stochastic effects begin, is a dose of 100 mSv (see Sect. 6.7). The graph in Fig. 5.2 shows that at least 100,000 patients must detect cancer with 90% certainty at this dose. The most powerful cohorts described in Chap. 7 approach this number. During the time of humankind’s acquaintance with ionizing radiation, a large number of population groups have been forced to accumulate, receiving once or receiving doses of radiation for a long time, which makes it possible to identify the effects of medium or low doses quite definitely. Some large groups of workers or the public, exposed to radiation for one reason or another, formed cohorts to which the methods of epidemiological

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Effective dose, mSv

103 102 10

Non-detectability area

1 0.1

1

10

102

103

104 105 106 107 108 Number of people studied

109 1010 1011

Fig. 5.2  Limits of cancer detection under irradiation according to the results of epidemiological studies

studies were applied. Analysis of the effects of radiation on these cohorts provides basic information about the effects of low doses. The results of such studies are discussed in detail in Chaps. 7–10. It should be noted that human studies provide less informative data than animal experiments, since, depending on the place of residence, lifestyle, and professional activity, people are exposed to various additional factors that contribute to the emergence and development of diseases, and among the various factors of chemical, bacteriological, and many other types, it is necessary to single out the influence of radiation. The impact of high doses of radiation on health is obvious. However, the role of medium and low doses can only be revealed by statistical methods. So, as a result of research on a particular object, radiobiologists receive experimental points, which mean, for example, the proportion of organisms that have received radiation damage in a given group, or the occurrence of a malignant tumor. Some curve is drawn through these points, which is best, i.e., with the smallest deviations, passes through these points. Scientists call this operation approximation or fitting. To construct a curve, a specific function is selected, and the curve is drawn relative to the measured points using various variants of the so-called “regression analysis.” The most famous and widespread is the “method of least squares.” This method selects the parameters of the function so that the sum of the squared deviations of the line from the points is minimal. Usually, several different functions are tried, corresponding to different models, and the one that best fits the experimental data is selected from them.

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Moreover, this “best” means that the choice is not made for “taste” but using strict statistical criteria. One of the most well-known criteria, best suited to the problems under discussion, is the Pearson criterion, otherwise known as the “chi-square” (χ2). The model of carcinogenesis adopted based on such work will be determined by what function is chosen as a result for an approximation—linear, linear-quadratic, a function with a threshold and/or with hormesis, etc. Figure 5.3 shows an example of different curves drawn over the experimental points using the least squares method. In this example, the authors specified three different functions describing the curves: linear, linear-quadratic, and linear with a threshold. The best approximation, i.e., the smallest value of χ2 was obtained for a function with a threshold (Fig. 5.3c), the threshold value in this case turned out to be 0.22 ± 0.14 Gy. The “dose-effect” dependencies are the most important result of experimental studies, the basis for the conclusion about the model of the action of low doses of radiation. Therefore, this chapter contains several more such graphs (Figs. 5.4 and 5.5). Similar graphs can be seen in other chapters: Figs. 8.5, 8.6, 8.7, 8.9, 8.11, 9.11, and 9.12. There are very few points in the area of low and medium doses, both on the given graphs and in the vast majority of other works. This is not the fault of the researchers, not negligence or misunderstanding, but the difficulty of conducting research in this particular area. Researchers tried to advance into the field of low doses as far as experimental techniques and statistics allowed them.

Probability, %

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Linear with a threshold

Linear-quadratic

Linear

4

2

0 0

1

2

3 0

1

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Dose, Gy

Fig. 5.3  Dependence of the probability of leukemia in mice. The three graphs show the same experimental points, but different approximation methods. (a) linear function, (b) linear-quadratic function, (c) linear function with a threshold. Using a statistical test shows that the threshold curve (c) best fits the experimental results. Figure based on UNSCEAR 2000 Report, Annex G, p. 26, Fig. X

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Probability, %

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Single dose

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Fractionated dose

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1

2

3

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Dose, Gy

Fig. 5.4  Probability of thymic lymphoma induction as a function of dose for single and fractionated X-ray irradiation. This figure was used as an example in UNSCEAR 2000 Report (Annex G). Figure on the basis of J.R. Maisin, A. Wambersie, G.B. Gerber et al. The effects of fractionated gamma irradiation on life-shortening and disease incidence in BALB/c mice. Radiat. Res. 94: 359–373 (1983)—https://pubmed.ncbi.nlm.nih. gov/6344131/

The accuracy and reliability of the results obtained significantly depend on the number of points in the dose range of interest. The more points, the higher the reliability of the conclusions made based on the experiment. The epidemiological method is now well-developed and has many real achievements, but it has one generic flaw. In the epidemiological method, personality is lost, individuality is lost, and the problem of the fate of an individual person disappears. A large number of stories have been published about the lives of some victims of the atomic bombing of Japanese cities, about the health problems of nuclear weapons testers, about the so-called downwinders, and so on, but in statistical tables, all personal dramas, tragedies, and struggles are hidden behind dispassionate numbers.

5.5 Radiosensitivity of Tissues, Organs, and Organisms The measure of the body’s response to the action of ionizing radiation can be assessed using a special parameter—radiosensitivity. This reaction can also be characterized by the reciprocal of radiosensitivity—radioresistance. The concept of radiosensitivity is very important both from a theoretical, general biological point of view and from a practical point of view. Knowledge of the

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1.3 1.25

Relative risk

1.2 1.15 1.1 1.05 1 0.95 0.9 0

0.1

0.2

0.3

0.4

0.5

0.6

Cumulative dose (Sv)

Fig. 5.5  Dependence of the excess relative risk of death from all types of cancer except leukemia on the accumulated dose over ten years according to the UK National Register of Radiation Workers. The total number of the cohort is more than 167 thousand people. Straight line—linear function. On the basis of R.G.E. Haylock, M. Gillies, N. Hunter, W. Zhang, M. Phillipson. Cancer mortality and incidence following external occupational radiation exposure: an update of the 3rd analysis of the UK national registry for radiation workers. Br J Cancer 119, 631–637 (2018)—https://www.nature.com/ articles/s41416-­018-­0184-­9#citeas

mechanism that controls radiosensitivity and its regulation will make it possible to control the response of tissues to irradiation consciously, weaken it to protect the body, and enhance it during radiation therapy of malignant tumors or inactivation of bacteria. Different organs of the human body have different sensitivity to radiation. Actively dividing cells are more sensitive—these are the cells of the hematopoietic tissue, the epithelium of the mucous membranes, the testes, and the ovaries. Neurons and muscle cells have minimal sensitivity. In slowly renewing tissues, radiation damage develops much later, and sometimes only after an additional pathogenic effect. For example, radiation damage to long tubular bones may manifest itself in the future only by delayed healing of fractures. As an example of extremely low radiosensitivity, we can cite the bacteria Deinococcus radiodurans, which quite safely withstand acute irradiation with a dose of up to 10 thousand Gy (for humans, a lethal dose of radiation is ~5 Gy). To consider differences in the response of different organs to irradiation, special parameters are introduced, the so-called “weighting coefficients,” and

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to determine the dose to an organ, the concept of “effective dose” is introduced. The effective dose of each organ is defined as the product of the equivalent dose by the weighting factor, and the effective dose of the body is the sum of the equivalent doses to all organs and tissues, multiplied by the weighting factors for these organs. Adding the effective doses of individual organs gives the total effective dose. With uniform irradiation, the effective dose will be equal to the equivalent, since the sum of all weighting factors is equal to one. The unit of effective dose is the same as the equivalent dose—sievert. The values of the weighting factors are given in the Appendix. The values of the weighting coefficients are set on the assumption that the same organs in different people are equally sensitive to radiation. Actually, it is not. The issue of individual sensitivity is discussed in more detail in Sect. 5.7. We also note that radiosensitivity to tissue lesions, i.e., to deterministic effects, and sensitivity to cancer induction, i.e., to stochastic effects, are slightly different. For example, in terms of cancer induction, the most radiosensitive organ is the lungs, and in terms of tissue damage, they are among the radioresistant organs.

5.6 Models of the Action of Low Doses of Radiation 5.6.1 Linear No-Threshold Model Very soon after the discovery of ionizing radiation, it became clear that high doses of radiation have an obviously damaging effect on living tissues, but these were mainly local radiation effects. At that time, the concept of “dose” had not yet been introduced, and the relationship between the dose (irradiation intensity) and the effect on a person was unknown. The most obvious manifestations of the effects of radiation on the body, when the damage could be quite reliably associated with radiation, were skin burns—erythema. The reservation about the reliable connection between burn and radiation is not accidental. Usually, radiation erythema occurs 6–8 days after exposure, and during these days there could be many other events that could lead to burns, and maneuvering around the kitchen, and unsuccessful actions in the workshop, etc. As a curiosity, we note that, for example, the famous scientist and inventor Nikola Tesla, who in the very first years after the discovery of X-rays worked a lot with X-ray equipment, believed that X-rays did not cause skin lesions, but by ozone formed during the operation of the equipment.

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It was only in 1925 that the first proposals for establishing maximum allowable doses appeared (introducing the concept of a tolerant dose), and the value of the tolerant dose was associated with the threshold of skin erythema. During and immediately after World War II, in the 1940s the construction of nuclear reactors, the production of large quantities of fissile materials, and the creation (and testing, and use) of nuclear weapons began. As a result, the intensity of radiation increased significantly, physicians were faced with a new, previously unknown phenomenon, radiation sickness. Research has provided extensive information about radiation sickness and serious radiation injuries, but what is happening in the field of low doses was unclear. It is obvious that to clarify unclear issues, it is necessary to conduct research, but working in the field of low doses, even with animals, is very laborious. It is difficult to transfer the data obtained from animal experiments to humans. At the same time, work with sources of ionizing radiation has expanded and expanded, so it was necessary to accept some rules. Such rules have been formulated. Biologists, physicists, and radiologists simply took the results under the action of radiation with doses from 0.2 to 3 Sv and extrapolated these results to zero, i.e., a straight line was drawn from the 0.2–3 Sv region to zero. This is shown schematically in Fig. 5.6. In principle, many studies have been done in this area, and many more points could be included, but all of them, with real measurement errors, make it possible to carry out linear extrapolation either to zero or to the threshold value with equal validity. Linear extrapolation means that the carcinogenic risk of radiation exposure is proportional to the dose, and even very small doses can induce cancer. Such a model of the action of low doses of radiation is called the Linear No-Threshold Model (LNT). The LNT model was originally adopted by the Commission on Genetics of the National Academy of Sciences of the USA and the Committee on the Biological Effects of Atomic Radiation (BEAR) in 1956. The governments of many countries quickly confirmed these recommendations of the Commission. In 1960, the International Commission on Radiation Protection—ICRP joined the recommendations. Finally, in 1975, the LNT model was adopted by the United States Environmental Protection Agency (US EPA). Over time, the LNT Model turned into a Theory, then into a Dogma, and, finally, into a Paradigm of radiobiology, which is still valid today. In its simplest form, this paradigm sounds like this: 1 . Radiation is harmful. 2. Radiation is harmful in any dose.

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Fig. 5.6  Linear no-threshold model. The numerical values of the doses are not indicated, because it is necessary to consider a wide range of doses, several orders of magnitude; therefore, to use a logarithmic scale along the x-axis, and on such a scale the linear function is described by a curved line, and the curved line on the graph will make it difficult for the reader to perceive the problem of linearity

3. There are no low-dose effects that cannot be predicted from the known effects of high-dose exposure. To this set of statements, it is necessary to add: the effect of radiation is additive, can accumulate over time, is incorrigible, and does not depend on the dose rate. According to this paradigm, which for a long time was supported by many radiobiologists, there is no problem of “low doses,” and it is meaningless to define the boundary of this area. The only thing that can be done is to determine the minimum doses at which damage can still be detected using certain techniques and methods of analysis. At the same time, it was assumed that even the natural radiation background is certainly harmful, it is simply irremovable in principle, which means that it determines the lower limit of the harmful effect of radiation on all living things.

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The history of the struggle for and against LNT is reflected in great detail in a large number of articles by the famous American scientist, currently the editor-in-chief of the Dose-Response journal, Edward Calabrese, formerly one of the founders and editor-in-chief of the journal Biological Effects of Low Level Exposures (BELLE) (Fig. 5.7). E.  Calabrese carefully studied the history of abolishing the concept of a threshold in the impact of radiation. He showed that the discoverer of radiation mutagenesis, Nobel laureate Hermann Muller, played the main role in introducing the no-threshold model. Working with Drosophila, he obtained a linear dependence of the mutation rate on the dose in the region of very high doses and extrapolated this dependence down to zero without any threshold. Muller recommended the use of a linear no-threshold model in his Nobel speech in 1946. At the same time, evidence of the existence of the threshold was already known. It was obtained by American scientists Ernst Caspari, who emigrated to the USA from Germany, and Curt Stern, well-known geneticists of that time, but Muller ignored them. Calabrese proved that the committee of the USA National Academy of Sciences with the participation of Muller was “motivated” and deliberately falsified the available data. This decision of the Committee was sponsored by the Rockefeller Foundation in the interests of oil companies. Calabrese accuses the founders of the LNT model of dishonesty and falsification of facts. Similar claims are made to the founders of the linear model on the website “The Hiroshima Syndrome.”

Fig. 5.7  Professor Edward J.  Calabrese, Chief editor of the journal Dose-Response. With permission of Professor E. Calabrese—https://hps.org/hpspublications/historylnt/ episodeguide.html

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The well-known American scientist Charles Sanders also paid much attention to this story. Chapter 3 of his 2017 book “Radiobiology and Radiation Hormesis: New Evidence and its Implications for Medicine and Society” is titled “The harmful and fraudulent basis for the LNT Assumption.” The titles of the sections of this chapter are characteristic: “A Scientific Scandal of the Last Two Centuries,” “Statistical and Observational Malfeasance,” and “Muller’s Deception and Russell’s Mistake.” In the papers of the well-known Canadian physicist and entrepreneur Jerry M. Cuttler one can find: “The recommendations of the US National Academy of Sciences had far-reaching consequences, they disorientated the world community cancer risk, but also much broader—on research in nuclear physics, on the use of nuclear technologies, nuclear energy and in medical practice both in the United States and around the world.” The modern attitude to the problem is well demonstrated by the title of an article by American specialists Bill Sachs, Gregory Meyerson, and Jeffrey Siegel, published in the international journal Biological Theory in 2020: “Epidemiology without biology: false paradigms, unfounded assumptions, and specious statistics in radiation science.” The dishonesty of radiobiologists who defend the LNT model is illustrated by a quote from the book by Charles Sanders “Radiation Hormesis and the Linear-No-Threshold Assumption”: The most dishonest, manipulative research I have ever seen in my nearly 50 years of participation in radiobiological research has been published by radiation epidemiologists who are proponents of the LNT assumption. Their hundreds of publications and involvement in national and international radiation protection agencies have put them in a position of power and control within the research establishment. They have continued the deception in spite of overwhelming published, scientific data that clearly demonstrates how wrong the LNT assumption is.

The application of the LNT model in practice is not as harmless as it might seem, it leads to serious consequences: Dangerous and unnecessary forced displacement of huge numbers of people near accidents at nuclear power plants. A growing, fear-driven refusal by many patients and parents to allow themselves or their children to undergo potentially life-saving X-ray diagnostic procedures. The vigorous anti-nuclear environmental movement spreads feelings of fear-uncertainty-doubt in the popular media and stimulates radiophobia.

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Reducing the number of operating nuclear power plants, a significant increase in the cost of protective measures, and reducing the efficiency of radiation technologies. Spending billions of dollars yearly on completely useless, and perhaps even harmful, protective measures and devices. Inflating radiophobia hinders the natural and safe disposal of nuclear waste. Serious massive psychological problems in large parts of the population of Europe, leading to the loss of human lives (more than 100,000 abortions and 1000 suicides attributed to Chernobyl fallout). However, let’s be lenient. At the level of knowledge of that time, the LNT model was perhaps a fairly reasonable concept. It had neither theoretical justification nor experimental confirmation, but at least guaranteed the relative safety of the population. There is no doubt that it played an important positive role in ending atmospheric testing of nuclear weapons. LNT turned out to be the most cautious, as it would now be said, the most conservative model, which, although it overestimated the risk of exposure to radiation in small doses, provided protection against the damaging effects of radiation. In particular, the famous Soviet scientist, the father of the Soviet thermonuclear bomb academician A.D. Sakharov relied on the LNT model in his struggle to prohibit nuclear weapons tests in the atmosphere. But by now, the LNT model has turned into a brake on the development of nuclear power and nuclear technologies. There is no doubt that the LNT has neither theoretical substantiation nor experimental confirmation; the LNT model is currently just a convenient simplification that guarantees the population’s safety. In fact, the fundamental issue is not linearity, but non-­ threshold. Starting from a certain dose, the effect may indeed depend on the dose linearly, although the linear-quadratic model turns out to be much closer to the truth. The main question is, is there a threshold? A huge amount of modern experimental material, described in Chap. 7, indicates that there is a threshold. The entire history of introducing dose limits has assumed that there is a safe level. The values of threshold doses and the history of their evolution are given in Sect. 5.7.

5.6.2 Dose and Dose-Rate Effectiveness Factor (DDREF) So, according to the LNT model, the risk of disease when exposed to low doses of radiation can be determined by extrapolating the data for high doses

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to the area of small ones. However, it gradually became clear that the real low-­ dose hazards are much less than the extrapolated values. It was decided to compensate for the obvious incompetence of linear extrapolation by introducing a special coefficient called the Dose and Dose Rate Efficiency Factor (DDREF), which reduces the role of radiation at low doses. Currently, the officially accepted value is 2, although it is understood that this is a conservative value, and the real value may be noticeable or even much higher. The question of the value of this coefficient has been the subject of quite a heated controversy in recent times. In a large number of articles, based on the analysis of the results of the studies, it is indicated that this coefficient can reach 30 in certain cases. The French Academy of Sciences report suggests that this coefficient can even be protective at low doses and low dose rates. Let’s take an example. Extrapolation of cancer risk data from a cohort of Japanese cities, that survived the atomic bombing, into the dose range of computed tomography predicts the serious danger of this diagnostic procedure and the emergence of a large number of new cancers in the United States annually (~30 thousand), which increases the total number of expected cancers by 2%. The data known today show the fallacy of such a calculation. The term DDREF contains a simultaneous indication of a change in the biological effectiveness of both low doses and low dose rates. Strictly speaking, these two kinds of variables must be distinguished. Dose rate efficiency is manifested in the fact that the damaging effect (biological efficiency) of acute exposure (short-term exposure with a high dose rate) is higher than chronic exposure (long-term exposure with a low dose rate) at equal total doses (more on this in Sect. 6.8). Various processing options for published data give DDREF values from 2 to infinity. The latter corresponds to the absence of harm at low doses, i.e., threshold concept. So, the LNT model is not fair and interferes with the normal relationship of humanity with radiation. Then what’s in return?

5.6.3 Other Models Next, we will indicate three mutually complementary models; each of these models is covered in a separate chapter: The threshold model—Chapter 7. Radiation safety. Indeed, if there is a dose threshold in the action of radiation, it is safe at doses lower than the threshold.

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The model with hormesis—Chapters 8 and 9. The usefulness of radiation. It will be shown that at doses lower than the threshold, a positive, stimulating effect of radiation, i.e., hormesis, can manifest itself. Low doses can treat. Special attention we pay to the particular kind of treatment – Radon therapy (Chap. 9). The Radiation Necessity Model (Radiation Deficiency Syndrome)—Chap. 10. The need for radiation. Numerous studies in low-background conditions show that vital activity is suppressed with a reduced radiation background.

5.7 Threshold Doses and Radiation Safety Standards One of the purposes of this book is to show that small doses are safe without questioning the dangers of large and medium doses. Naturally, it is essential to indicate the boundaries between different dose regions. Faced with manifestations of dangerous doses, physicists and biologists set specific boundary values. Exposure to doses above these limit values was considered hazardous. The current radiation safety standards are formulated mainly under the influence of the LNT model discussed above and are recognized as erroneous by many radiobiologists. In this section, we will show how historically, as new knowledge has been gained, ideas about acceptable exposures have changed. In Sect. 6.7, after getting acquainted with the mechanism of the action of ionizing radiation on living cells, we will indicate the real, at the level of modern knowledge, boundary values and compare them with the current official standards. The understanding that the newly discovered radiation was dangerous became clear quite quickly after the discovery of X-rays and radioactivity. The physicists, who studied radioactive radiation, and the physicians, who used these radiations, worked with them for the first years without any precautions or protection. Translucent of their patients, the doctors themselves received a specific dose of radiation daily. The hidden harm caused by these rays accumulated from day to day. Ten to 15 years after this practice, a mass defeat of radiologists with malignant tumors began. Many enthusiasts of this new diagnostic method died. For more information on radiation’s impact on radiologists’ health, see Sect. 7.5. In 1936 in Hamburg, a monument was erected “to the victims of radium and X-rays” in front of the Hospital of St. George. The monument was

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inscribed with the names of 110 scientists and engineers who fell victim to the first experiments with X-rays. Subsequently, new names were constantly applied to the monument, and very soon, it had to be surrounded by additional slabs. By 1959, the list of victims had already included 360 names. With the accumulation of information about the damaging effects of radiation, the understanding of the need to take some measures grew. Radiation societies began to emerge in some countries, formulating radiation protection rules. All these measures cannot be called clear and definite since physicists and radiologists have not yet been able to measure radiation doses reliably and have not determined the specific biological effects that occur under the influence of certain doses. But in fairness, it must be said that the first exhaustively precise rule, the truth of which no one doubts so far, was proposed just a year after the discovery of Röntgen in 1896 by the American engineer Wolfram Fuchs. In modern form, the three basic principles of practical radiological protection are—time, distance, and shielding. For the best protection against radiation, spend as little time as possible near the source, as far as possible, and use protective shields. Decisive progress began in 1925 when the First Radiological Congress met in London. The main focus was quantifying radiation doses, and the X-Ray Unit Committee was organized for this purpose. In 1928, the Second Radiological Congress met in Stockholm. It announced the organization of the International X-ray and Radium Protection Committee (IXRPC). Out of respect for the host country, the chairman of the Stockholm Congress was elected the Swede Rolf Sievert, the one whose name in the future will be called the unit of equivalent and effective doses, but according to historians of science, the main organizing role was played by two people— George Kaye from the British National Physical Laboratory and Lauriston Taylor from the US National Bureau of Standards. During the Second World War, the committees and commissions suspended their activities. Still, after the war, in 1950, through the efforts of Taylor and Sievert, the committees were reorganized, renamed, and resumed their work. The Committee on X-Ray Units became the International Commission on Radiation Units and Measurements (ICRU), and the International Committee on Protection from X-Rays and Radium Radiation became the International Commission on Radiation Protection (ICRP). The above–mentioned L. Taylor was the secretary of the ICRP during 1934–1953, then in 1953–1969, he was the first permanent Chairman, and from 1969 until the last days of his life (he died in 2004 at the age of 102)—Honorary

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Chairman. Describing the activities of L. Taylor, his biographers do not miss the opportunity to report that by the end of his life, he had 18 grandchildren, 24 great-grandchildren, and two great-great-grandchildren. Both the ICRU and ICRP commissions are active to date and largely determine all policies in dosimetry and radiology. In addition to them, an important role is played by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), the International Atomic Energy Agency (IAEA), and the Committee on the Biological Effects of Ionizing Radiation (BEIR). Perhaps the first major step in the quantitative characterization of the effects of radiation on living tissues was the introduction of the “tolerant dose” concept, formulated in 1925 by Dr. A. Mutscheller. Since the most obvious manifestations of the effects of radiation on the body were skin burns, Mutscheller suggested connecting the allowable dose with the onset of skin erythema. Rolf Siegert proposed a slightly different value at almost the same time. These ideas were later combined, as seen in Fig. 5.8. In modern units, the limiting dose was ~0.5 Sv/year. After the discovery of uranium fission, the outbreak of World War II, and especially in the work on creating nuclear weapons, research into the biological effects of ionizing radiation became sharply intensified. Then came nuclear power plants, a large number of enterprises for the manufacture and processing of nuclear fuel and nuclear weapons materials, for the development,

Fig. 5.8  Development with time limits for occupational radiation exposure and for the radiation exposure of the public from 1924 up to now

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manufacture, and operation of radionuclide devices. It turned out that there are many different radionuclides with different properties and hazards for the body. It became clear that external and internal irradiation is possible, and they differ in dose distributions and effects. It was necessary to introduce limit values for the internal content of radioactive contamination and limit values for the concentration of radioactive nuclides in air, water, and food. The first cases of acute radiation sickness appeared; before that doctors dealt mainly with local lesions or with what we now call stochastic effects, i.e., with delayed onset cancer. All people who, in principle, could be exposed to radiation were divided into two groups—personnel and the public. Personnel are people who directly work with sources of nuclear radiation. These are adult healthy people who, before being hired, undergo a medical examination and then, in the course of work, their health is subjected to periodic monitoring, and the population is all the rest, including the least protected from the effects of radiation—children, pregnant women, the elderly, and sick people. It is obvious that the limiting norms for these groups must differ. The introduction of official units in which doses are measured began with the “roentgen,” approved in 1928 at the ICRU congress in Stockholm. This unit is still used quite often. The unit roentgen determined the absorbed dose in the air. To more accurately account for the absorbed dose in biological tissue, in the second half of the 1940s, a new unit was introduced: “roentgen equivalent physical—rep,” in 1960, it was replaced by a “rad.” To correctly take into account the biological effects in the irradiated tissue, a new unit was proposed at the same time: “roentgen equivalent man—rem,” officially adopted in 1962. In 1960, at the 11th General Conference on Weights and Measures, a standard was adopted, which was called the “International System of Units” (the abbreviation SI—from French Système International). After that, the introduction of this system in various countries began. New dosimetric units had to be introduced to comply with the new system. Instead of “roentgen,” “rep,” and “rad,” the unit of absorbed dose became “gray,” introduced in 1975. Instead of “rem,” the unit of equivalent and effective doses became “sievert,” introduced in 1980, five years after gray. About Lewis Harold Gray and Rolf Maximilian Sievert, whose names were used for two new units see Sect. 5.1. As knowledge of the health effects of ionizing radiation has evolved, increasingly stringent regulations have been developed and dose limits have been adjusted. Further, we will see that this adjustment occurred with an overlap,

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that the norms became excessively rigid, not corresponding to modern scientific data. In the future, new clarifications of the rules and regulations are coming. Changes in dose limits for occupational exposure and public exposure over time are shown in Fig. 5.8. It can be seen that the limit values became less and less over time. It is important that all limiting norms were determined from the data of measurements in the region of high doses using the LNT model. The basic concept of radiation protection was formulated in ICRP documents in 1977. Separate requirements were adopted for professionals and the public. Irradiation doses were supposed to be limited in such a way as to completely exclude tissue (deterministic—non-stochastic) effects and bring the probability of stochastic effects to an acceptable level. In 1954, the so-called ALARA principle (As Low As Reasonably Achievable, considering social and economic factors) dominated the practice of using ionizing radiation for a long time as a natural development of an LNT model. One of the shortcomings of this principle was the emphasis on economic rather than scientific considerations. But since we are talking about an “acceptable” level, then, naturally, the question arises—what level is considered acceptable? Regulators have suggested comparing the radiation hazard with other hazards. We offer such a comparison to the readers of this book in Chap. 11. Considering the risk probabilities for many activities, the ICRP ruled (in 1977) that the risk associated with a dose of 50 mSv per year could be considered “acceptable.” 1990 an important step was taken toward harmonizing international radiation protection and safety concepts. The IAEA Committee on Radiation Safety (Inter-Agency Committee on Radiation Safety—IACRS) was created. The “Basic International Safety Standards” were adopted within the Committee on Radiation Safety framework. As a result of long-term work and numerous studies, basic radiation safety standards have now been established. They are quite complex because, due to the different sensitivity of different organs to the action of radiation, the norms for selective action on different parts of the body differ. The nuclear-­ physical properties of various radionuclides differ noticeably; therefore, it is necessary to establish their standards for maximum concentrations in air, drinking water, food, and the surrounding space. Radiation safety standards regulate in detail various options for exposure—natural, medical, in the conditions of a radiation accident, during exposure of various population groups.

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Here we give the norms for irradiation of the whole body, i.e., effective dose limits. The limit value of the effective dose for personal is 20 mSv in a calendar year in all European countries (in the USA 50 mSv per year). The limit value for the effective dose aimed at members of the public is 1 mSv in a calendar year, both in Europe and in the USA. The radiation background in different countries and even parts of the same country can vary markedly. In addition, radiation from medical procedures is now also included in the background radiation, and such exposure varies even more among different segments of the population, but if we do not affect special areas with a significantly increased background, we can roughly estimate the radiation background with values of 3–6 mSv/year. Please note that the maximum permissible level for the population (1 mSv/year) is less than the natural radiation background. Radiobiologists get out of this contradiction cunningly: 1 mSv/year is the maximum radiation dose rate over the dose from background radiation. Radiation safety limits are set on the assumption that all people are equally sensitive to radiation. Sensitivity differs in people of different ages, in men and women, but even for people of the same sex and age, there is a substantial variation in radiosensitivity. There is even a different radiosensitivity in left-­ handers and right-handers; in left-handers, it is higher. Several pathological conditions contribute to increased radiosensitivity, including immune dysfunctions such as autoimmune diseases and acquired immunodeficiency syndrome (AIDS). Currently, there is an intensive search for biological markers that would make it possible to determine individual radiosensitivity. Attempts to find the genes responsible for radiosensitivity have so far failed. Individual radiosensitivity concerning tissue injury and stochastic effects can be considered a multifactorial trait. Some of the factors on which radiosensitivity depends are likely to have a genetic origin. Still, there is substantial evidence for the impact of lifestyle factors such as smoking, alcohol consumption, diet, lack or excessive physical activity, physical injuries, or hygiene. It is obvious that the organization of radiation protection measures creates a significant economic burden on all work with sources of any kind and the country’s budget as a whole. It can be expected that since the presence of a threshold of stochastic effects and radiation hormesis have received convincing confirmation, dose limits will be revised upwards shortly. However, it would probably be advisable to identify the most vulnerable subgroup of the population—pregnant women and children and set more stringent standards for them.

6 The Effect of Radiation on a Living Organism, the View from Inside

6.1 Radiobiological Paradox In the very first years after the discovery of the damaging effect of X-rays and radioactivity, even before the beginning of the XX century, a paradoxical circumstance became clear: the absorption of negligible radiation energy leads to severe damage and even death of the body. So, for example, irradiation with a dose of 10 Gy, i.e., 10 J (joules) for every kilogram of the body obtained in a fairly short time (hours, days), kills any mammal. Kills not instantly but rather quickly, in a few days. At the same time, it is easy to calculate that it is precisely this energy, i.e., about 10 joules fall on every square centimeter of the human body per minute on a clear sunny day. Actually, sunlight is absorbed by the skin’s surface, and ionizing radiation—in volume. So, if we consider the real mass of the part of the body in which the energy is absorbed (and the dose is energy per unit mass), sunlight gives a noticeably larger dose than 10 Gy. At the same time, you can lie on the beach for hours. Other comparisons can be made. For example, a lethal dose of 10 Gy affects a negligible number of molecules in biological tissue. A rough estimate shows that about a hundred billionth of the body’s molecules undergo ionization. A dose of 10 Gy, absorbed by a person weighing 70 kg, corresponds to the thermal energy of only 170 calories. Recall that a calorie is the energy required to heat 1 gram of water per 1 degree. An absorbed dose of 10 Gy can heat the human body by at least one-thousandth degree (the thermal effect is equivalent to about a glass of hot tea drunk). So, this is a paradox: 10 Gy of ionizing radiation can kill any animal but simultaneously bring to the body relatively small energy. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2023 I. Obodovskiy, From Radio-phobia to Radio-euphoria, Springer Praxis Books, https://doi.org/10.1007/978-3-031-42645-2_6

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The German scientist, biophysicist, and philosopher Friedrich Dessauer was the first to suggest that the outcome of the action of radiation depends on the probability of accidental hits of discrete portions of energy in these vitally important microvolumes—targets. He assumed that in the cell, there are structures more important and less important for life. The principle of a direct hit and the theory of the target were further developed and clearly formulated in an article published in 1935 by the Russian geneticist Nikolai Vladimirovich Timofeev-Resovsky, who worked in Germany, the German radiobiologist Karl Zimmer and the American biophysicist, future Nobel laureate (1969) Max Delbrück, “On the nature of gene mutations and the structure of the gene” (Über die Natur der Genmutation und der Genstruktur), which soon became known as the “Three-Man Paper.” One of the creators of quantum mechanics and also a Nobel laureate, the great Austrian theoretical physicist Erwin Schrödinger, relied on the considerations expressed in this article in his famous book “What is Life? The Physical Aspect of the Living Cell.”

6.2 Radiation Targets in a Living Cell 6.2.1 Living Cell In this section, we will briefly describe the main target of ionizing radiation in a cell and how a living cell works, and why these targets play such an important role. In principle, ionizing radiation acts randomly and bombards everything that gets in its way. For the damage to random molecules that occurs during such bombardments to affect the vital activity of the organism, it is necessary to destroy many molecules, which requires very significant doses. In fact, as noted in Sect. 6.1, the absorption of negligible radiation energy leads to severe damage and even death of the organism. This is due to a violation of the normal operation of the control system, namely, the genetic apparatus. All living organisms are built from cells. Moreover, a single cell is also an organism. The cell was the elementary unit of all living organisms’ structure and vital activity. The first cells that appeared on Earth were quite simple. They stored genetic information in a single volume and synthesized the necessary proteins. These cells do not have a special repository of genetic information—the “nucleus,”

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so they are called “prokaryotes.” Such cells have survived to this day—these are bacteria. Approximately 1.5 billion years ago, there was a transition from prokaryotes to much larger and much more complex cells with a nucleus. Now the storage of genetic information has turned out to be separated from the rest of the cell’s life processes in a special compartment—the nucleus. Such nuclear cells were called “eukaryotes.” Typical sizes of prokaryotic cells are 0.5–5 μm, while eukaryotic cells are 10–50 μm. The cell is bounded by a membrane and filled with “cytoplasm,” in which cell components—organelles, including the nucleus, float or sit attached to the membrane. The main substance of the cytoplasm is water (60–90% of the total mass of the cytoplasm). Simply put, the cytoplasm is a broth in which many organic and inorganic substances float in dissolved or insoluble form. The majority of the most important functions in a living cell are performed by “proteins.” All “enzymes” that catalyze the basic processes in the cell are composed of proteins. The structural elements of the “cytoskeleton” that maintain the shape of cells are built from proteins. Proteins collagen and elastin are the main components of connective tissue, ligaments, tendons, cartilage, bone tissue, and the middle level of the skin—the dermis. Hair, nails, and bird feathers comprise another structural protein, keratin. Proteins carry out motor functions—muscle contraction, cell movement, and movement of flagella and cilia. Receptors that perceive light, sound, mechanical action, smell, and taste are built based on proteins. Finally, hormones that perform signaling functions are also proteins. Proteins are built from amino acids connected in sequence, figuratively speaking, head to tail. There are extremely wide varieties of amino acids, but wildlife uses only 20 well-defined amino acids. The proteins necessary for the cell are synthesized according to a program recorded in a special information carrier that controls the cell’s work, in the “deoxyribonucleic acid” (DNA) molecule. DNA is part of the chromosome—a complex of DNA molecules and special proteins—“histones.” The chromosome is so named because it is a body (soma) that stains well with certain dyes, which makes it easier to observe under a microscope. Chromosomes are located in the nucleus, which occupies a central place in the cell (often in location, but mainly ideologically). Many components that comprise the nucleus have received the appropriate names: “nucleic acids,” “nucleotides,” etc.

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Chromosomes combine in pairs, so the number of chromosomes is always even. During sexual reproduction, one pair’s chromosomes is inherited from the father, the other from the mother. The chromosomes of a pair are called homologous (from the Greek “similar”), i.e., with the same (or almost the same) set of genes and with their similar location on the chromosome. In total, there are 23 pairs of chromosomes in human cells, i.e., there are 46 chromosomes in total: 22 pairs of chromosomes, numbered in order 1–22, as well as X and Y chromosomes. Each somatic cell has a complete set of paired chromosomes, i.e., they are diploid. Female reproductive cells—“ova” and male—“spermatozoa” contain a single set of 23 chromosomes each, i.e., they are “haploid.” Eggs have two X chromosomes, while sperm has either an X or an Y.

6.2.2 Molecules of Deoxyribonucleic Acid” (DNA) The DNA molecule consists of two polymer chains linked together and curled into a double helix. The backbone of each chain consists of alternating phosphates and sugars. The two sugar-phosphate backbones of the DNA molecule are linked by chemical compounds called “nitrogenous bases” because their nitrogen exhibits basic, i.e., alkaline properties. The connection of the cores with bases is shown in Fig. 6.1. Part of the backbone of the DNA molecule, deoxyribose, and phosphate with a nitrogenous base attached to them is the monomer from which the DNA polymer molecule is built. This monomer is called a “nucleotide.” The diameter of the DNA molecule is 2 nm, the length depends on the organism. The DNA of the simplest viruses contains only a few thousand links, bacteria—several million, and higher—billions. The total length of DNA in all human chromosomes is about 2 m, it is curled into a right helix (Fig. 6.1a). DNA is a double helix, but for understanding many genetic processes, helicity is not an important property, but double-strandedness and complementarity of base bonds are important. These properties of DNA make it possible to store and reproduce genetic information stably and reliably. Therefore, many processes associated with DNA can be shown in a flat drawing of a molecule, shown in Fig. 6.1b. Only four nitrogenous bases bind DNA backbones, two from the “purines” class and two from the “pyrimidines” class.

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Base pairs Adenine

Thymine

Guanine

Cytosine

Sugar phosphate backbone

Fig. 6.1  Schematic representation of a DNA molecule in a helical (a) and flat (b) view. The figure is made by the author using the fig from MedlinePlus, Genetics, What is DNA—https://medlineplus.gov/genetics/understanding/basics/dna/. Public domain

Purines are “adenine” (A) and “guanine” (G). Pyrimidines are “cytosine” (C) and “thymine” (T). The connection of the two backbones of the DNA molecule occurs as follows: the purine of one backbone is always connected to the pyrimidine of the other: A is connected to T and vice versa (A-T), G is connected to C and vice versa (G-C). We will show in a separate figure an extremely important rule— the base pairing rule (Fig. 6.2). The formation of long sequences of nucleotides, in which only specific pairs are connected one against the other by the rule formulated above, turns out to be a remarkable property of DNA that allows information to be stored. This pairing property is called “mutual complementarity.”

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Fig. 6.2  The base pairing rules

6.2.3 Molecules of Ribonucleic Acid (RNA) In addition to DNA, another macromolecule, “ribonucleic acid” (RNA), plays an important role in the work of the genetic apparatus. DNA performs the function of the main carrier and transmitter of genetic information, and RNA implements this information. Both molecules are linear polymers built from monomers called nucleotides. Unlike DNA, RNA is single-stranded and uses ribose instead of sugar deoxyribose. In addition, the place of one of the bases, thymine (T), is occupied by uracil (U). The rest of the bases are the same as in DNA. DNA is the store and transmitter of genetic information. RNA performs several functions in the implementation of genetic information. Accordingly, several types of RNA are distinguished: • Messenger RNA (mRNA) carries information about the structure of the protein from DNA to the ribosome, where the necessary proteins are assembled according to the plan recorded in DNA. The process of mRNA synthesis on a DNA template is called transcription. The share of mRNA accounts for approximately 0.5–1% of the total RNA content of the cell. • Transfer (tRNA), which carries amino acids to the site of protein synthesis in ribosomes. Of the total RNA content of the cell, tRNA accounts for about 10%. There is at least one tRNA for each of the 20 amino acids. Transfer RNAs are short; they consist of only 80–100 nucleotides. • Ribosomal (rRNA) is involved in the assembly of proteins according to the mRNA template from amino acids delivered to the ribosome by transfer RNAs. The process of protein synthesis is called translation. Of the total RNA content in the cell, rRNA accounts for about 90%. Ribosomal RNAs are the largest; their molecules contain 3–5 thousand nucleotides.

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• S m a l l RNA: microRNA—miRNA and small interfering RNA—siRNA. miRNA and siRNA each contain 22 nucleotides. Both types of small RNAs, miRNAs, and siRNAs, are involved in the epigenetic control of gene expression but differ in origin. miRNAs are internal molecules synthesized in cell operation; they are part of the organism on the path of its evolution. The destruction of these molecules leads to disruption of the organism’s normal functioning up to its death. siRNAs are molecules that enter the cell from the outside, particularly introduced by a virus. All these types of RNA (except siRNA) are synthesized from DNA during transcription, i.e., DNA contains information not only about the structure of proteins but also about the structure of RNA. When messenger RNA copies information about the order of amino acids, adenine (A) in DNA corresponds in RNA not to thymine (T), but to uracil (U).

6.2.4 Genes Genes, i.e., nucleotide sequences that encode proteins do not go in a DNA molecule in a row. It turned out that they alternate with non-coding sequences. The parts of DNA containing genes are called exons, and the rest are called introns. It needs to be clarified why introns are needed, it is assumed that introns are partly used for gene expression, and partly they are garbage, waste products of evolutionary changes. The calculation of the number of genes in the human genome has been carried out for a long time, gradually being refined. As of the summer of 2022, the full genome sequencing as a result of the Human Genome Project showed that the human genome contains 19,969 active, i.e., coding genes, which is ~1.5% of the total DNA volume. Information about the structure of proteins is recorded in DNA in the form of a sequence of nucleotides. The set of rules determining the correspondence of nucleotides and amino acids is called the genetic code. All known proteins are built from 20 amino acids; DNA-encoding proteins have only four bases. This number of amino acids can only be encoded using three bases per amino acid. The combination of three bases is called a “codon” (Fig. 6.3). One codon codes for one amino acid. Several hundreds or thousands of codons make up one gene encoding one protein.

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Fig. 6.3  Codon. This is the name of a triplet—three consecutive nitrogenous bases in a DNA chain that codes for a specific amino acid. The figure shows four codons and indicates the amino acids for which such a combination of bases (nucleotides) codes

The set of codons that encode a single protein is called a “gene.” Gene (from the Greek génos—genus, origin), the elementary unit of heredity. At the initial stages of the development of genetics, it was believed that each gene carries information about a certain trait or function of the body. In reality, each gene determines the structure of one of the proteins of a living cell, and this protein already affects a trait or function.

6.2.5 Cell Division The emergence of a new organism and its subsequent growth occurs due to cell division. Even in an intact adult organism, new cells are needed to maintain its normal functioning; several million new cells must be formed every second. Most often, new skin cells, mucous membranes, and blood components are formed. So, the life span of intestinal epithelial cells is 1–2 days. About 70 billion of these cells die every day. Red blood cells, erythrocytes, live only 100–120 days; about 2 billion of them die every day. The life span of leukocytes is even less. The skin’s stratum corneum cells are continuously exfoliated and fall off, and new ones come in their place. During cell division, the information about the structure of proteins recorded in the DNA, must be stored and used. Its accuracy and reliability of storage must be checked, and, if necessary, this information storage must be repaired. The information transmitted during division from the parent cell to the daughter cell is genetic.

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Genetic information is written in DNA in a three-letter code, where a letter is one nucleotide, and a word is one gene; biologists call such a triplet code. Since there are more codes than amino acids, the code is degenerate, several codons correspond to some amino acids. Finally, the code is non-overlapping; the same nucleotide cannot be in two consecutive triplets. So, the code is triplet, degenerate, and non-overlapping. In addition, the code is universal for all wildlife, it is the same for bacteria and higher animals. Work with genetic information is carried out by genetic processes: • Cell division (mitosis) • Replication—making a copy of DNA before each cell division • Transcription—the transfer of information about the sequence of amino acids in a certain protein from DNA to matrix RNA and translation—the assembly of proteins in the ribosome from amino acids according to the RNA matrix • Reparation—DNA repair

6.2.6 Cell Cycle The totality of processes occurring in a cell from one division to the next and ending in the formation of two new generation cells is called the “cell cycle.” At certain moments of the cell cycle, the DNA structure is checked in the so-called checkpoints, which could be disturbed by external reasons, for example, by radiation or, more often by internal reasons due to errors in the implementation of genetic processes. If the check detects an error in the structure, the repair mechanism is activated, restoring the normal structure. In this case, the duration of a cell cycle increases. If the test reveals that the DNA has been damaged beyond repair, then a pre-programmed special cell removal procedure called “apoptosis” is activated in the cell. Apoptosis (from the Greek “falling leaves”) is a variant of cell death in which the cell breaks up into fragments, and the fragments are carried into the extracellular space and further into the excretory systems or absorbed by other cells. According to the figurative comparison of the American biologist and popularizer of science Buddhini Samarasinghe, who published a series of popular articles on the main features of cancer in Scientific American in 2013, the apoptosis program is “hardwired” into the genome of each cell, like a capsule of potassium cyanide is sewn into the edge of the collar of every classic spy. In

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case of danger, the spy bites through the capsule, and the cell triggers a program of apoptosis. Biologists call apoptosis the internal police or biological toileteers. Through apoptosis, the body gets rid of unnecessary, “used” or defective cells. The duration of cell cycles in different tissues, in different species, and at different stages varies very widely—in an early frog embryo, it can be less than one hour. In humans, in the intestinal epithelium cells, and in the hematopoietic cells of the bone marrow, the cell cycle lasts 12–20 hours. In a number of cells of other tissues, it can be several days or even weeks; in the liver of an adult, it can be more than a year. The delay in a division is one of the obvious results of the impact on the cell of damaging factors, particularly radiation.

6.2.7 Epigenetics Encoded in the linear sequence of DNA bases, genetic information determines (through RNA) the structure and function of the entire set of proteins that various cells need. For a long time it was believed that the order of genes in DNA is the only and complete information about the structure and function of the cell. However, gradually the fog from the fascination with the first successes of molecular genetics began to give way to the realities of experimental biology. At present, the initial ideas about the functioning of genes are being substantially supplemented. One has to admit that in addition to the level of genetic information concentrated in genes and controlling protein synthesis, there is another level called “epigenetic.” Translated from the Greek preposition “epi-” means “above.” If genetics studies the processes that lead to changes in genes, in DNA, then epigenetics studies changes in gene activity, in which the structure of DNA remains the same. The relationship between genetics and epigenetics can be determined in the words of the English biologist, Nobel laureate (1960) Peter Medawar: “Genetics proposes, epigenetics disposes.” In 2020, a book was published in Russia about genetics, more precisely about the possibility of identifying a person by analyzing the genome. The author is the well-known Russian scientific journalist Elena Kleshchenko, editor-in-chief of the PCR.news portal. The book was entitled “DNA and its man. A brief history of DNA identification.” Around the same time, a book on epigenetics by the Spanish geneticist and editor-in-chief of Epigenetics, Manel Esteller, appeared in Spanish. The book is called “I am not my

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DNA. Genetics proposes epigenetics disposes.” (Original Spanish title: “No soy mi ADN. El origen de las enfermedades y cómo prevenirlas.”) These two titles quite clearly clarify the relationship between genetics and epigenetics. The organism develops from a single cell, the genes of which contain complete information about the organism. When dividing, this information passes to all emerging cells. All cells of any tissue contain the same genetic information recorded in DNA molecules, but during the organism’s development, this information in tissues or organs is read selectively. Somehow the cells determine which organ they belong to. In liver cells, only those genes are activated, and only those proteins are synthesized that are necessary for the functioning of the liver; in kidney cells, genes necessary for the performance of kidney functions are activated, etc. With an unchanged DNA structure, turning genes on and off, regulating their activity, called gene expression, is a manifestation of epigenetics. The study of identical twins made a significant contribution to epigenetics. Because identical twins share the same genome, any differences between twins are determined by environmental influences, not genes. One of the clearest examples of the manifestation of epigenetic mechanisms is the metamorphosis of insects—the transformation from a caterpillar to a chrysalis and then to a butterfly. All three creatures have the same genome, but they look and behave completely differently, only the epigenetic program has changed. Another example is the specialization of the bee colony. It is known that in a bee colony, there are several castes of bees, particularly worker bees and queens. Worker bees live only a few weeks, and queens—for several years, the queen is almost twice as large as worker bees, she continuously lays eggs and never leaves the hive, and worker bees are not able to have offspring and constantly fly out of the hive for collection of flower nectar. However, the queen and the worker bees at the larval stage had the same genome, and only epigenetic marks, the presence of which in turn depends on nutrition, determine which of the bee larvae will become queens and which worker bees. To date, several mechanisms of epigenetics have been elucidated. These are DNA methylation, histone modification, and changes in the concentration of specific microRNAs. Let’s talk here in more detail about one of the most apparent mechanisms—methylation. The process of DNA methylation was discovered in the 1970s. Specifically, one of the nitrogenous bases, cytosine, is methylated. The methyl group CH3 is attached to cytosine, as a result of which cytosine is converted to methylcytosine. Methylation occurs under the action of the enzyme “methyltransferase.” This does not prevent the pairing of the formed methylcytosine with a

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complementary base—guanine. Still, methyl groups prevent the nucleotides that form messenger RNA from approaching DNA, physically prevent reading information from DNA and, thereby, reduce or turn off the activity of the corresponding gene. The methyl group is called the gate valve on DNA. Such valves are shown schematically in Fig. 6.4. In a fertilized egg, methyl groups are quickly removed to almost zero, since all types of somatic cells develop from it, and any coding gene may need to work. With the organism’s development, cells acquire their own specifics, inherent in the organ in which this cell is found, the action of many genes is no longer required, and methylation begins. At a certain stage of fetal development, the methylation level reaches a maximum. In the cells of adult mammals, more than two-thirds of the corresponding regions are equipped with such valves. Methylation level does not remain constant throughout life, it is influenced by many environmental factors, particularly stress, toxins, diet, viruses, exercises, and radiation. Changes in the genome—mutations, if they are not rejected by the mechanisms of repair, apoptosis, or immunity, are not eliminated. On the contrary, epigenetic marks significantly depend on environmental factors and the individual’s behavioral patterns. The most important, universal change in methylation with age is its decrease, the slow consequences of the morbid consequences observed by the “aging” of the body group. A decrease in methylation level is called “hypomethylation” in biology. The methylation level over time was quite clear and almost linear, at least in some places of DNA.  UCLA mathematician and biological statistician Steve Horvath has shown that by measuring the level of methylation, it is possible to determine the biological age of cells with an error of not more than three years. This is more accurate than many other estimates of cell age. Against the background of general hypomethylation in some DNA regions, the concentration of methyl groups, on the contrary, increases; this is called “hypermethylation.” Since methyl groups control the activity of genes, depending on which gene becomes active due to hypomethylation, or the

Methyl group

Fig. 6.4  Methyl groups on DNA (epigenetic tagging)

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activity of which gene, on the contrary, is suppressed due to hypermethylation, various diseases can occur. In particular, epigenetics is believed to be relevant to cancer, Alzheimer’s disease, atherosclerosis, hypertension, diabetes, and some other diseases.

6.3 Disorders in the Genetic Apparatus. Mutations, Mutagenesis 6.3.1 Mutations A clear order of bases (nucleotides) arrangement in a DNA chain can be violated. Such violations are called mutations (from the Latin mutatio—change). By definition given for the first time in 1901 by the Dutch botanist and geneticist Hugh de Vries, mutations are any changes in the genetic apparatus, in the entire genome, in individual chromosomes, their parts, or in individual genes. Genomic and chromosomal mutations, the latter called chromosomal aberrations, lead to significant rearrangements in the structure of the genetic apparatus. At medium doses, gene mutations mainly occur associated with a change in the nucleotide sequence in the DNA molecule. There is some inconsistency in the use of the term “mutations.” Sometimes this is what any damage in the structure of DNA is called, but according to a strict definition, mutations are only those changes that are not eliminated by biological defense mechanisms, are fixed, and can be transmitted to offspring, A group of point mutations affecting one or more bases can be distinguished in gene mutations. This does not mean that they are of little importance. As we will see below, point mutations can significantly affect the functioning of a cell. Point mutations can be of the following types: • Deletions—the absence of one or more bases in its place • Substitutions—base pair substitutions • Insertions—the inclusion of one or more bases in new places in the DNA molecule Mutations such as deletion and insertion can be in two versions when the disappearance of bases or their insertion is a multiple of three or not a multiple. Since the genetic code is a triplet, the insertion and deletion of bases in a number that is not a multiple of three, leads to a shift in the division into

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codons. Such mutations are called “frame shift.” A codon shift completely changes the encoded amino acids in the part of the protein that comes after the shift. In the case of DNA, among the 64 codon variants, only three codons are meaningless, i.e., they do not correspond to any amino acid, they stop protein synthesis. So it may be that the code resulting from the mutation corresponds to some protein, but it is doubtful that such a protein will be neutral or even beneficial. As for mutations that change only one codon, then options are possible. Since the code is degenerate, i.e., one amino acid corresponds to several codons. It may happen by chance that a codon change does not change the type of amino acid and, therefore, does not change the protein. Sometimes the replacement of one amino acid has little effect on the properties of the protein. The mutation may occur in a region that does not encode a protein, i.e., in the intron. It will also not affect the structure of the protein, although it may affect its expression. But there are times when this replacement plays a huge role. A frequently cited example is a mutation associated with a change in the sixth amino acid in the hemoglobin beta chain. There should be glutamic acid, and valine appears in this place due to a mutation. This mutation is responsible for a severe disease called sickle cell anemia, in which the shape of the oxygen-carrying cells in the blood (red blood cells) changes, and they essentially lose their ability to carry oxygen. In another example, the substitution of one amino acid (lysine for glutamate) of 487 consecutive amino acids in the enzyme aldehydrogenase, which is responsible for removing acetaldehyde from the body, which accumulates during the oxidation of ethyl alcohol, leads to increased sensitivity to alcohol. So, point mutations can have three consequences: • Preservation of the meaning of the codon (silent mutations) • Change in the meaning of the codon (missense mutations) • Formation of a meaningless codon (nonsense mutations) In addition to nitrogenous bases, the sugar-phosphate backbones of the DNA molecule can also be damaged under the influence of radiation; these backbones can be torn, as shown in Fig. 6.5. Breakage of one chain is usually relatively easily corrected by the reparative mechanism of the cell. The rupture of two chains is much more difficult to repair and can lead to very serious consequences.

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Double break

Breakage of a backbone Cluster break

Fig. 6.5  Various types of damage to the sugar-phosphate backbone of DNA. A single break in the figure on the left and double and cluster breaks in the figure on the right. For cluster breaks see Sect. 6.5

Mutations in somatic cells have been discussed above, but they can also form in germ cells. In this case, if the reparative mechanism does not remove the mutations or does not lead to immediate cell death, the descendants will inherit them. In this case, the following options are possible: • These mutations will not lead to any consequences for the phenotype; for example, these are mutations in non-coding regions, introns. • There will be small, harmless changes in the phenotype. One of the manuals on genetics gives an example of such a change: the kitten will have a slightly drooping ear. • Mutations will lead to severe changes in the phenotype of the offspring. True, for the most part, mutations in essential genes are lethal to the cell or even to the organism. It is clear that in this case, the transmission of such a mutation by inheritance stops, and they do not cause more harm.

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It is also important to point out that mutations are random. It is impossible to predict which factor in which gene will cause a mutation. Mutations can be beneficial, neutral or harmful but have nothing to do with the organism’s needs. Various factors can affect the frequency of mutations, but they do not affect their direction. The probability of mutations has nothing to do with their usefulness or harm to the body. So far, we have discussed DNA damage involving one or more molecules. However, DNA bond breaks and the dissociation and fragmentation of different parts of DNA can lead to changes in the structure of chromosomes observed in an optical microscope called “chromosomal aberrations.” The formation of chromosomal aberrations was fairly accurately related to the absorbed radiation dose, so their determination formed the basis of the “biological dosimetry” method.

6.3.2 Mutagenesis First of all, we note that mutations can occur spontaneously, without the influence of external factors. Spontaneous mutations arise due to the thermal movement of atoms in the DNA molecule due to replication and repair errors and due to the action of active chemical agents, called “radicals,” formed in the processes of chemical transformations of substances in the body. Radical formation is the most abundant source of DNA damage. As a result, according to the totality of all internal processes in each average human cell, various damages are formed per day, including 26 thousand base losses, approximately 50 thousand pyrimidine dimers, and about 100 thousand single-strand breaks (according to Russian scientist A.N. Koterov’s lecture in the book “Actual radiobiology”). In total, before repair, a cell’s DNA contains almost 200 thousand spontaneous structural disturbances. Repair eliminates the resulting damage, reducing their number to about 100 per cell daily. At this stage, the mechanism of removing damaged cells with the help of apoptosis comes into play, and then immune surveillance takes over, eliminating foreign cells. As a result, real damage is reduced to one per cell per day. This is the background of spontaneous mutations. However, the number of spontaneous and metabolically induced DNA damage is noticeably greater than those caused by low-dose irradiation. On this basis, it is concluded that the contribution of low doses of ionizing

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radiation is negligible, that natural background radiation adds almost nothing to spontaneous damages. Mutations due to ionizing radiation are described in Sect. 6.5. This also includes mutations caused by hard ultraviolet radiation (UV-C). One of the main causes of mutations is the action of chemicals. A mutagen molecule, a substance alien to the body, as biologists say, a genotoxicant, having passed numerous barriers placed by nature in the body to prevent the penetration of toxic substances into it, including the membrane of a cell, and then of a nucleus, and waiting for the time when DNA for replication or repair unwinds (it is much more difficult to get close to packed DNA) enters into chemical interaction with DNA.  As a result of the reaction, bonds between atoms are broken in a section of DNA and a structural defect appears—a mutation. So far, it has not been possible to separate mutations that have arisen under the influence of various factors. So, the background of mutations is a set of spontaneous mutations and mutations under the influence of the natural background of ionizing radiation and the natural background of chemicals in the environment.

6.4 What Cancer Is One of the most common and dangerous consequences of exposure to radiation in doses that are usually classified as medium and large is cancer. Cancer is a collective concept that unites about 200 different diseases of various organs and tissues. Regardless of the various forms of the course of these diseases, methods of treatment, and prognosis, they all have one common feature—the unrestrained reproduction of cells that have gone out of control of the regulatory and coordinating mechanisms in the body. If tissue cells multiply in this way, a tumor (neoplasm) occurs. Oncologists call such a disease—solid cancer. It is possible that blood cells, hematopoietic tissue, and the immune system can transform into a malignant form. Such cancers are called liquid; these are leukemias (cancer of the blood) and lymphomas (cancers of the lymphatic system). Cancer has several important standard features. The first is a long latent period between the initiation and the moment it can be diagnosed. A schematic graph of the change in the number of deaths per year from cancer over time since exposure is shown in Fig. 6.6. The second is the strong dependence on patient age; the real dependence is slightly different, but, in most cases, it is near the sixth power of age.

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Mortality, %

25 20 15 10

Leukemia

Non-cancer diseases

5 0 1940

1960

1980

2000

2020

2040

Years

Fig. 6.6  The number of additional deaths per year from leukemia (1), non-cancer diseases (2), and solid cancers (3) associated with radiation, according to the time elapsed since the bombing of Japanese cities. The portion of the curve before 1950 is shown as a dotted line since there is no data for this period. The dotted line after 2005 is the forecast. (See also Fig. 7.5)

Third, it should be noted that the quantitative characteristics of danger, such as the incidence and mortality rates for various types of cancers, may vary considerably. The highest frequency is manifested by such cancers as lung cancer, 55.8 per 100,000, breast cancer for females—67.0, and prostate cancer for males—54.7. Much less likely cancers of bones and joints—0.9, of the small intestine—2.3, and of the brain—6.0. Fourth, the risks of various cancers also vary considerably. Survival of lung (18%), liver (17%), and pancreas (8%) cancers are relatively small; they very likely lead to death. Survival of men with prostate cancer (99%) and women with breast cancer (91%) is high. Thyroid (98%) and skin (91.1%) cancers are much less malignant. From Fig. 6.6, it can be seen that at first, with a delay of only a few years, leukemia appears and dominates for about 20 years after exposure and then almost completely disappears. Leukemia was the first type of cancer found in the survivors of atomic bombings. Radiation is more likely to induce leukemia than all other cancers for an extended period after exposure. So, leukemia is often considered the “marker” of radiation effects. Tumors or, as oncologists call them, solid cancers, have a longer latency period. They rarely appear in the first 10–15 years, but then, new cancer cases can be diagnosed for at least 50 years. Any mutations described in Sect. 6.3, regardless of the way they occur, either cause cell death due to apoptosis or lead to a change in its function.

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This is how warts, papillomas, polyps, cysts, adenomas, and other defective tissues appear on the skin and internal organs. Still, the most dangerous, fortunately, not the most frequent transformation of mutated cells is their malignant degeneration and cancer development. Thus, mutations may be the basis of carcinogenesis. According to the most common cancer model, both the primary tumor and metastases grow from a single damaged cell, i.e., they form a clone. A defective cell passes on its abnormality to offspring, i.e., the damage must be heritable. It is very important that for cancer initiation, disorders of the genetic and epigenetic apparatus must manifest themselves in the offspring of the affected cells. This is only possible with dividing cells. Even at the dawn of radiobiology, in 1906, French scientists Jean Bergonie and Louis Tribondeau formulated a rule that has since been named after them. According to this rule, the danger of cancer induction under the action of radiation directly depends on the ability of cells to reproduce at a given moment in time. The rule was formulated for radiation damage, but it is valid for any methods of influencing the cell’s genetic apparatus: first of all, “everything that divides” is affected. The formation of mutations is called mutagenesis. According to modern ideas about the nature of cancer, carcinogenesis is caused by mutagenesis. Violations of the work of the genetic apparatus can also occur and be transmitted epigenetically, i.e., caused by epimutations that alter the epigenome. Cancer initiation occurs when mutations are introduced into certain positive and negative regulatory genes that control cell division. Positive regulatory genes directly control, for example, the processes of passing through the stages of the cell cycle, the processes of replication, repair, and mitosis, they stimulate cell growth. Normal genes that, when mutated, stimulate the cell to become cancerous are called “proto-oncogenes.” As a result of mutation under the influence of damaging factors, particularly under the influence of radiation, they turn into “oncogenes”. Negative regulator genes inhibit or even prohibit processes that should not occur in a normal cell, for example, prohibit the passage of cell cycle checkpoints by a cell with a damaged genome or restrict cell growth where it should not occur. Genes that encode proteins related to negative growth regulators are called “antioncogenes” or “suppressor genes.” In a living organism, many cells regularly fail and must be replaced by new ones. New cells should also appear in case of any wounds, operations, etc. This means, firstly, the cells must receive a signal to divide, and, secondly when the required number of cells is formed—a signal to stop dividing. Cancer cells differ from normal cells in that they can, firstly, divide without a

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command, and secondly, they are insensitive to signals that stop the growth of the number of cells. In particular, a certain mutation can turn off the apoptosis program in a cancer cell. The main factors that cause cancer are the same as the factors that cause mutations: • • • •

Spontaneous cancer arising from internal causes Hereditary cancer The action of chemicals—carcinogens (chemical carcinogenesis) Exposure to radiation, including ultraviolet radiation (radiation carcinogenesis) To them are added:

• Viruses (infection) • Irritation (inflammation) For a long time, spontaneous cancer’s role was believed to be insignificant and estimated at a few percent. However, relatively recently, in a series of articles by highly respected American scientists, oncologist Bert Vogelstein and a specialist in biostatistics and bioinformatics Christian Tomasetti, it was suggested that up to two-thirds of cancers can be caused by internal causes. Cancer survivors are just unlucky that some cell divisions have occurred with many mutations in their bodies. It is still difficult to definitively estimate the proportion of spontaneous cancer. Hereditary cancer is associated with mutations that occur in the germ cell and are passed on to the next generation. The typical proportion of hereditary cancers is 5–10%. According to modern concepts, the most important cause of mutations and possible subsequent cancer is the action of chemicals. According to some estimates, chemical carcinogenesis accounts for 60–90% of all cancers. For historical and psychological reasons, society has developed a strong prejudice against ionizing radiation and a much more relaxed attitude toward the dangers of chemical exposure. In fact, due to the widespread use of various synthetic substances in industry, agriculture, and everyday life, many chemicals alien to the body, xenobiotics that are not included in the natural biotic cycle, have appeared in a person’s immediate environment. The link between cancer and smoking has been firmly established. It is considered an established correlation of mortality from malignant tumors with alcohol consumption per capita.

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There are not just many different substances, but many different types of substances, each type requires its own chemical analysis, and there are only a few ionizing particles—alpha, beta, and gamma; neutrons must also be considered in a strict analysis. That’s all. Rather simple devices reliably register all radiations. Viruses can also be the source of mutations. For this section, it is essential that viruses can integrate into the genome of the host cell and thereby reprogram its systems. So, with some reservations, we can assume that viruses also cause mutations. In addition to mutations that lead to a change in the genome, cancer can have a different, epigenetic cause, when the genes themselves do not change. Cells become cancerous because biochemical switches can turn oncogenes on and suppressor genes off.

6.5 The Effect of Ionizing Radiation on Biological Structures 6.5.1 Direct Action The American scientist Hermann Muller discovered the mutagenic effect of radiation in 1927 and was awarded the Nobel Prize in Physiology or Medicine in 1946. Ionizing particles, X-rays, and gamma quanta fly through living cells randomly and interact with all the molecules they come across. As a result, the molecules are destroyed and cannot function in the cell. If the damaged molecule is a protein-enzyme molecule or of some cell organelle, then this is sad, but it may not be fatal. In the processes of synthesis occurring in the cell, new molecules can be produced to replace the damaged ones. Therefore, if there are not many such damaged molecules in the cell, i.e., the radiation dose was not very high, the cell may recover and continue normal life. To destroy a sufficient number of molecules, large portions of energy are required, and as we already know, very serious problems for the body, up to its death, arise with a rather small amount of absorbed energy. This happens during the ionization of DNA molecules—the main target of ionizing radiation. This is the so-called direct action of radiation. Physicists and chemists have conducted and continue to conduct detailed studies of the processes of radiation interacting with vital macro-molecules. The effect of radiation was studied separately on nitrogenic bases, on

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nucleotides, and on sections of the DNA molecule in dissolved and crystalline form. Irradiation was carried out with flows of electrons, ultraviolet, X-ray, and gamma quanta, with alpha particles and heavier ions. The general conclusion is that, as a result of ionization, molecules dissociate into fragments with a noticeable probability. It produces mutations. Elementary radiation damage to the bases or the sugar-phosphate backbone of DNA is the same as in cases of spontaneous mutations and mutations under the action of chemicals. But ionizing radiation can also cause such damage that occurs very rarely or does not occur at all with other methods of action on DNA. These are cluster breaks—a concentration of lesions close to each other. When several lesions occur simultaneously at a small distance from each other, within one or two turns of the DNA helix, then such lesions, called “clusters” and shown in Fig. 6.5. It is very difficult to repair such damages, in this case, the DNA literally falls apart into pieces. Double breaks and cluster damage distinguish the action of radiation from spontaneous effects. They lead to the appearance of violations of the structure of chromosomes observed in an optical microscope, the so-called chromosomal aberrations. The vast majority of DNA structural defects, especially base defects and single-strand breaks are corrected with high efficiency by the repair system. The situation is more complicated with double breaks, but the cell can correct even double breaks in several different ways. In a popular form, it is difficult to describe the repair mechanism of double breaks, simplifying that a cell can use a homologous (sister) chromosome to repair double breaks. The most dangerous are cluster damages. Serious damage to DNA by radiation is the result of high doses. Small and medium doses create some small amounts of damage, which are corrected by the repair system. If the repair system does not cope with the work, then the mechanism of programmed removal of the defective cell, apoptosis, is activated. If the cell survives in this case, then it will go through the process of division, the damage will turn into a mutation, and the cell will pass on the defective genes to offspring, but the body also has an immune system that, having detected a foreign cell, can destroy it. Radiation can also affect all components of epigenetics: DNA methylation, histone modification, and the functioning of small RNAs. The main obvious manifestation of the action of radiation is a decrease in the proportion of methylated DNA bases, so-called hypomethylation. This process is schematically shown in Fig. 6.7.

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Fig. 6.7  Hypomethylation under the action of radiation

As is known, DNA damaged by radiation can be restored by repair mechanisms, but methyl marks, if any, are not restored. This is how the number of methyl marks decreases, i.e., hypomethylation occurs. Different types of body cells react to radiation damage in different ways. The most dangerous damage is in frequently dividing cells. If the cell does not divide, and in a living organism, there are tissues in which cells divide very rarely, then single defects that have arisen in the DNA will not manifest themselves in any way. We know that the most sensitive to radiation are rapidly renewing normal tissues—germ cells, blood, hematopoietic system cells, epithelial cells of the gastrointestinal tract, and skin. Radiation damage to these tissues manifests itself quickly. Neurons and muscle cells have minimal sensitivity. In slowly renewing tissues, radiation damage develops much later, sometimes only after an additional pathogenic effect. For example, radiation damage to long tubular bones can manifest only by delayed fracture healing.

6.5.2 Indirect Action As the biological effects of radiation exposure on cells and organisms were studied, the understanding was accumulated that the observed effects could not be explained only by the direct action of radiation. Passing through the cell, ionizing particles will most often destroy water molecules since there are most of them in the cell. The interaction of radiation with water has been studied in great detail.

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Water is a unique substance on Earth and maybe in the Universe. In search of life on other planets, scientists focus on the temperature conditions of the planet. It is assumed that life is possible only in such temperature conditions in which liquid water can exist, and if there are no visible traces of water, as, for example, on Mars, then traces of the existence of liquid water in the past are searched for. Water is important in creating and maintaining life on Earth, shaping the climate and weather. It is the most important substance for all living beings on planet Earth. A significant part of the volume of a living cell is the cytoplasm, which consists mainly of water. In the intercellular space, water in the form of lymph also plays a significant role. Without exception, water is necessary for all of Earth’s unicellular and multicellular living beings. Water is the most common solvent on planet Earth, largely determining the nature of chemical processes. Most of chemistry, at its inception as a science, began precisely as the chemistry of aqueous solutions of substances. Water is a model object of radiation physics and chemistry, just as the hydrogen atom is a model object of atomic physics. Water in many nuclear reactors acts as both a moderator and a coolant while exposed to powerful radiation fluxes. The need to understand the processes occurring in this case in water and possible changes in its properties is one of the most important reasons for a detailed study of various transformations of water molecules under the action of radiation. The complex of diverse reactions that occur in water under the action of ionizing particles is called “radiolysis.” One of the important products of radiolysis is the so-called free radicals, relatively stable molecules with high reactivity. Radicals can enter into chemical interactions with DNA molecules, resulting in damage or mutations in DNA components. It is this effect of radiation that is called “indirect.” Observations also confirmed the role of indirect action. In particular, a comparison of the effects of irradiation on vital macromolecules in a dissolved and dry state showed that in a dissolved form, DNA molecules are several orders of magnitude more sensitive to irradiation than in a dry state. It is natural to assume that water radiolysis products significantly contribute to the lesions. It is essential that radicals can diffuse in the cell, moving from the place of formation to DNA, and can even be transmitted from cell to cell. The products of oxidation by free radicals of cell substance molecules turn out to be quite long-lived; they can produce a damaging effect not only in the cell where they were formed but when they get into the blood, they can be transported

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far from the place of their formation and have a pathogenic effect there. Such products of radiolysis are called radiotoxins. The presence of oxygen enhances the efficiency of the formation of radiolysis products and, consequently, the effect of irradiation. Radiobiological studies on the irradiation of cells of various tissues in the presence of oxygen in them have shown that with an oxygen concentration in the cell corresponding to its normal content in the atmosphere (~ 21% = 159 mm Hg), a three times lower dose is required to achieve such the same effect as in the absence of oxygen. It should be noted that radiolysis products are formed in cells and in normal metabolic processes. Since most of these products contain oxygen, they are called Reactive Oxygen Species—ROS.  The body has a complex set of protective antioxidant systems to prevent their excessive accumulation and correct the resulting damage. Therefore, the damaging effect of radiolysis products manifests itself at doses at which antioxidant systems no longer cope with their work. In conclusion, we note that, according to many researchers, the total contribution of indirect action reaches 90% and is decisive in cell death under the action of ionizing radiation. Considering the effect of radiation on a living organism, we can draw an important conclusion: the cells that make up the body’s tissues are a dynamic system in which repair processes compete with damage processes.

6.6 Bystander Effect and Genome Instability In describing the impact of radiation on living cells and organisms, two more phenomena should be mentioned: extra-target effects and genome instability. For most of the XX century, radiobiology was dominated by the concept that a cell was damaged only if a charged particle lost energy in it. Damage could occur due to direct action on DNA or indirectly through free radicals, but necessarily in this cell. The repair mechanism could repair the damage, and then the cell survived, or this mechanism could not cope, and then the cell died. Some of the damage could be identified as mutations that showed up when the cell tried to divide. It was generally accepted that if a cell managed to go through five divisions, then it could be considered that it had escaped defeat and its offspring would behave as if they had never been exposed to radiation. However, since the middle of the twentieth century, evidence began to accumulate that radiation can cause damage not only to directly irradiated

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cells, but also to tissues that were outside the irradiation field, in neighboring or even distant parts of the body. This phenomenon is called the “off-target effect.” Often these effects are abbreviated as RIBE—radiation-induced bystander effect. Off-target effects are manifested, in particular, during radiation therapy. So, for example, in a patient with advanced melanoma, local irradiation of one tumor destroyed the other, which was outside the irradiation field. The existence of off-target effects means that an irradiated cell can transmit a signal to non-irradiated bystander cells. Suppose off-target effects are understood to be phenomena not only separated in space but also in time. In that case, the effect of genomic instability (radiation-induced genomic instability—RIGI) can also be attributed to off-­ target effects. This effect lies in that no visible damage can be detected in irradiated cells, and they appear only in subsequent generations. As the well-known Russian radiobiologist A.N. Koterov has convincingly shown, having processed a huge number of published materials, none of the options for off-target effects, neither spatial nor temporal, i.e., neither RIBE nor RIGI appear in the low-dose region or have not yet been discovered, so here we will limit ourselves to mentioning these interesting effects.

6.7 What Are “Low Doses” and What Are “Low Dose Rates” 6.7.1 What Are “Low Doses” Let us recall the definitions. Large doses are dangerous or even very dangerous, causing obvious tissue damage and radiation sickness. Medium doses do not create visible effects but cause long-term effects, usually cancer, but low doses are precisely those doses that not only do not cause any negative consequences but are safe, useful, and necessary. The concept of dose is used in cases of relatively short-term radiation exposure. In the case of long-term exposure, when the dose is accumulated gradually, the total dose usually plays a relatively weak role, and most importantly, the dose rate, i.e., its accumulation rate. A discussion of the role of dose rate will be held a little later, but let’s talk about doses now. The problem of the boundaries of the influence of various factors on a person is an absolutely universal problem that haunts a person all his life. Readers

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know that at very low temperatures, one can get frostbite or even freeze to death. The danger lies in waiting for us on the other side: at very high temperatures, one can get burned or even burn. Readers can easily navigate between dangerously low and dangerously high temperatures. The same can be said about air pressure. To the tops of the highest mountains on Earth, where the pressure is very low, climbing is difficult or even impossible without an oxygen device. Divers can tell about the problem of high air pressure, and here there are no problems for readers. You also must deal with dangerously small and dangerously large doses of sweet, salty, and many other foods. The author wanted to mention alcohol in this series but realized he did not know whether there was a danger of too small doses or a complete rejection of alcohol. However, in this case, there is no doubt that very high doses are dangerous, and small ones are definitely useful. It is probably useful to clarify that in the above examples, different people perceive the boundaries of the regions in different ways. Someone lives quite safely in the Arctic Circle, but in the Sahara, it would be uncomfortable for him, but for someone, it’s vice versa. A similar situation occurs with respect to radiation. It is clear in advance that the boundary of the area of low doses cannot be clear, it will be different for different living organisms, for young and old people, for healthy and weakened people. It will depend on what effect of radiation is considered, and what kind of damage is considered. So, for example, a dose of 10 Gy will be absolutely lethal for humans, small, not cause damage to some radioresistant reptiles, and favorable for the growth and development of seeds of some plants. Depending on biological criteria, the same organism’s radiation dose will be small or large. Doses of the order of 1 Gy for a person will be small if the death of the organism is taken as the criterion for damage, and at the same time large enough to cause a mild form of radiation sickness, a sharp rise in easily observed chromosomal aberrations in blood lymphocytes. However, based on extensive studies in which people of different sex, age, health status, socio-economic indicators, etc., were forced to take part, it was possible to obtain a certain limiting dose value that is safe for almost everyone. Low doses are currently being discussed in detail in scientific circles and in the circles of politicians, civil specialists, and environmentalists. This topic is a field of desperate struggle between different points of view. Based on the discussion of this topic, the most important decisions are made to protect the population and the environment. The author hopes this book will help readers understand and navigate the problem of radiation doses.

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So where is the upper limit of low doses? The problem of determining the border of small doses is analyzed in great detail by the well-known Russian radiobiologist A.N. Koterov. Many of the conclusions presented below are based on the material of his articles. The most obvious way to determine the quantitative criterion of small doses is a medical one. It is determined by the dose below which neither morbidity nor mortality of a person, nor long-term consequences can be observed. The results of epidemiological studies accumulated to date are fixed in the documents of authoritative national and international organizations: the International Commission on Radiation Protection (ICRP), the National Committee on the Effects of Atomic Radiation (NCDAR), and others. They found that the upper limit of the low-dose region for weakly ionizing radiation, i.e., radiation with a small LET (X-rays and gamma quanta) lies in the region of ~100 mSv. There are no proven stochastic effects below these values. Thus, the modern scale of dose ranges for low LET radiation (X-rays and gamma rays) has the form shown in Fig. 6.8. Small doses occupy the range of up to 100 mSv, and medium 100 mSv—1 Sv. We declared medium doses as a range of stochastic effects. In fact, the situation is more complicated. The point is that stochastic effects can also manifest themselves in the region of high doses. People who have had radiation sickness and are cured may subsequently have long-term effects and with a very moderate probability. If thanks to intensive and immediate treatment, a person managed to avoid rapid death at an almost lethal dose of 5 Sv, then the probability of subsequent cancer is approximately 25%. In addition, tissue effects begin to appear even in the Stochastic effects Radiation injury Tissue effects Lethal doses Necessary

1

Safe

10 Very low

100 Low

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1000 Medium

High

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Very high

Fig. 6.8  The scale of dose ranges for weakly ionizing radiation. The real boundaries between the types of action of radiation are not as clear as it is shown in the diagram. They depend on age, gender, health status, immune status, and, apparently, many other factors

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range of medium doses, starting approximately from 0.5 Sv to 1 Sv. Such a result of irradiation is called radiation injury. Doses above 1 Sv—radiation sickness. In addition, adding the regions of very low doses, less than 0.01 Sv, and the region of very high doses, more than 10 Sv, would be expedient to the list of dose regions. Note that for strongly ionizing radiation, for example, for alpha particles, the limit of the range of low doses depends on the nature and energy of the particles and can vary over a wide range.

6.7.2 What Are “Low Dose Rates” If the body is in the radiation field for a long time, it is necessary to use the concept of dose rate when analyzing the effects of radiation. Determining the boundary of the low-dose-rate region is an important task not only for radiobiology but also for the practice of using radiation. It is useful to know the boundary between dangerous and safe dose rates to navigate reasonably. For example, in the capital of Russia, Moscow, on the banks of the Moskva River, a nuclear repository was discovered from burials, or rather, discharges of radioactive waste by the Polymetals plant back in the late 1940s–1950s (Sect. 4.11.2). The question is whether it is necessary to avoid this area, and the residents of nearby houses to move as soon as possible, or vice versa, to come for a walk on this coast once or twice a week to get useful, and, as the author claims, even a necessary, dose of radiation for free? There are several approaches to determining the upper limit of a low dose rate. The most logical approach is considering the reparations of the resulting DNA lesions. A living organism is a dynamic system, and its stable state (homeostasis) is determined by the competition of damaging and restoring processes. On this basis, it can be assumed that such an intensity of ionizing radiation is considered low, at which the average time interval between two successive lesions of the same cell nucleus allows complete repair of damage caused by the first hit event. Experience shows that the cells of higher animals repair most of the DNA damage in the first minutes or hours and almost all the rest within 1 day after radiation exposure. Then the average time between two hits in the nucleus of a mammalian cell, equal to one day, corresponds to an X-ray dose rate of 0.13 mGy/hour ~1 Gy/year. Dose rates less than this value can be considered safe. This is three orders of magnitude greater than the dose rate of external exposure from natural background radiation.

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6.8 More About Dose Rate So, the effect of radiation on the body is characterized by two parameters— dose and dose rate. The dose determines a relatively short-term effect, and the dose rate determines a long-term effect. In this case, if the accumulated dose is essential, it is found by multiplying the power by the duration of action. In the context of this book, the author considers it necessary to pay attention to the special role of the dose rate. The fact is that many people are exposed to long-term exposure with a low dose rate, in particular, everyone, the entire population of the globe, is exposed to natural, and sometimes not very natural, radiation background, and it is unlikely to receive a decent dose at a time. This is the fate of a few, and perhaps none of the readers. When discussing the impact of low (and medium) doses of radiation on health, if doses are given, it is usually the cumulative dose. First, let us show with a simple example the role of the dose rate. This example walks through many articles and books on the effects of low doses of radiation. One hundred aspirins taken at the same time, i.e., at once a large dose, with a 50% probability lead to death. The same dose stretched for a hundred days, one tablet a day is a medicine. The limiting values of hazardous and safe dose rates are clearly linked to the duration of exposure. For example, during the explosion of a nuclear bomb in Hiroshima, the exposure lasted only 15 seconds. So, a person under the influence of a seemingly lethal dose rate of one hundred thousand Sv/year received a completely safe dose of 0.05 Sv, but intense short-term exposure is a rare case. The most likely option, as mentioned above, is long-term exposure with a specific dose rate. A general illustrative result of the analysis of the state of health depending on the dose rate for long-term continuous exposure is shown in the graph in Fig. 6.9. The unit “dose per year” can be used for long-term uniform exposure. If the exposure lasts less than a year or is uneven in time, one must use the unit “dose per hour” (or for an even shorter period). The area of high doses is located on the right side of the graph (curve 1 in Fig. 6.9). In this area, the impact of radiation on health has been studied in detail—this area has quite reliable results. From this area, the linear function is drawn to the threshold, as shown in the graph in Fig. 6.9. Arguments supporting the existence of the threshold, obtained from many studies, are collected in Chap. 7.

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Threshold Cancer risk

3

0.1

1

1

100

10

1000

104

2 Dose rate, mSv/year

Fig. 6.9  A summary picture of the dose rate-effect relationship. 1—Area of high dose rates. The reduced curve is a linear function drawn to a threshold through known and quite reliable data. In semi-logarithmic coordinates, the linear function does not look like a straight line, but a curve, as seen on the graph. 2—Hormesis region, radiation is not just harmless but useful at a dose rate less than the threshold. Curve 3 shows the area of radiation deficiency

At dose rates below the threshold, there is an area of hormesis (curve 2 in Fig. 6.9), where radiation turns out to be a useful factor. A detailed theoretical, experimental, and epidemiological justification of this area is given in Chap. 8. At even lower doses, there is an area of deficiency syndrome exposure, the area of doses insufficient for normal life, about it—in Chap. 10. It is known that the lethal dose for short-term (up to an hour) exposure is approximately 5 Sv. If the irradiation is extended for two weeks, the limit of fatal consequences shifts to the region of high doses by about 2 Sv, and if for a month, then it doubles and reaches ~15 Sv. A lethal short-term exposure dose received during a lifetime is safe and maybe even useful. The average natural low-LET background from external exposure is approximately one mSv/yr. Modern data allow us to consider that this is the minimum dose rate of the hormesis region and the initial value of the required radiation region. The dose rate value at which the hormesis area is replaced by the area of dangerous values, i.e., the threshold, according to various estimates, is in the range of 0.5–5 Sv/year. On the graph, this threshold value is taken equal to the smallest of the specified values, i.e., ~ 0.5 Sv/year. The optimal value of the radiation dose rate corresponding to the greatest benefit for the body, according to T. Luckey, is 60 mSv/year.

7 Safety of Low Radiation Doses

7.1 Cohorts of Irradiated People Experiments on humans are ethically vicious, inhumane, and officially prohibited. However, during humankind’s acquaintance with ionizing radiation, many population groups have accumulated, receiving once or a long-time dose of radiation, which can be attributed to the area of “low doses.” Groups of people on whom the effect of a damaging factor is studied, as we already know (see Sect. 5.4.1), are called “cohorts” by epidemiologists. Some members of the cohorts received significant doses, fell ill, or even died. The danger of large doses is obvious, beyond doubt, and is not discussed in this book. Therefore, when describing all cohorts, the main attention was paid to searching the scientific literature for information about the danger or safety of low doses. This book describes the effects of radiation on health for 12 cohorts. Moreover, each is a complex of several, sometimes many, smaller but still very significant groups of people associated in life or work with ionizing radiation. Just listing the cohorts collected in this book shows the amount of data from which information can be drawn on the impact of low doses on human health. In the listed groups, in some cases, there was a single acute exposure with a high dose rate; in others, the accumulated dose was received over a long time with a low dose rate. In some groups, exposure was purely external; in others, it was both external and internal; and in some cases, it was only internal. There is also some difference in the type of radiation affecting different groups. In other words, the obtained observational data have a wide range of irradiation conditions. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2023 I. Obodovskiy, From Radio-phobia to Radio-euphoria, Springer Praxis Books, https://doi.org/10.1007/978-3-031-42645-2_7

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In world literature, all cases of exposure to radiation on a person are divided into four groups. The first cohort is the cohort of the Japanese cities of Hiroshima and Nagasaki that survived the atomic bombing, more than a hundred thousand people at the end of World War II. This is a large group of people whose health has been monitored for a long time, for more than 75 years. Usually, information on the relationship of radiation to health in all other cohorts is compared with information received from the Japanese cohort. Another cohort is people undergoing radiation medical procedures, millions of people. The number of people in this cohort significantly exceeds those in all the others. The two remaining cohorts are workers exposed to ionizing radiation on an occupational basis and the population subjected to exposure involuntarily. In this chapter, in some cases, we do not separate groups exposed professionally and involuntarily under the same conditions. Therefore, the population of Chernobyl and Fukushima and the liquidators of these two accidents, radiologists and patients of medical procedures, crews, and aircraft passengers are united in this book by the place and nature of the impact, each in its section.

7.2 Radium Girls The “radium girls” case described in Sect. 4.4 illustrates the safety of radiation when elementary rules are followed. The girls covered the hands and numbers of the clock with paint that glowed in the dark under the action of the radium contained in the paint, licked the brushes, and thus swallowed a certain amount of radioactive liquid. As a result, some of them developed osteosarcoma. The “radium girls” case became widely known due to public attention. As a result, new rules for carrying out work and certain norms of labor legislation were developed. The factories continued to work until the end of the 50s of the last century, but after the measures were taken, no more troubles associated with radioactivity arose. Studies have shown that the ingestion of radium into the body of girls in the period 1955–1959 compared with 1915–1919 decreased by about a thousand times. The study of the radium girl cohort began in the middle of the sixties and was terminated in 1990. The researchers could find 2383 girls (at that time quite adult women) for whom reliable body content of radium could be reliably determined. Radium entered the body mainly by licking brushes during the entire work period and deposited in the bones until such a practice was

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banned. And then, for decades, it irradiated the body with an almost constant intensity since the half-life of radium is 1600 years. The graph well illustrates the health situation of radium girls in Fig. 7.1. The graph clearly shows the presence of a threshold in the induction of cancer by consuming a radioactive substance that emits alpha particles. The definition of this threshold is one of the essential results of the “radium girls” case. Of the 2383 women examined, only 64 had a total dose of 10 Gy and developed sarcoma. This colossal threshold value, lethal in short-term exposure, as seen in Sect. 6.7.1, should not be surprising. This is the dose accumulated over a long period. Most girls who worked with radioactive paint lived quite a prosperous life without any radiation effects, and some lived very long lives. Approximately 1000 were still living when the study was terminated in 1990. In December 2014, the death of Mae Keane at the age of 107 years was reported, who, in her youth, worked at one of the factories where light compositions were applied. In July 2015, another worker, 104-year-old Mabel Williams, died. For many years, every year, she went to the Argonne National Laboratory for radiation scanning, until in the late 70s she was excluded from the research program. There was no need for them. M. Williams’ obituary states that she had three great-great-grandchildren at her death. The “radium girls” case has become one of the most researched and most often cited cases in the history of medical physics. This case also became the material for one of the first epidemiological studies of the effects of incorporated radionuclides on health.

Sarcomas per person-year

0,03 0,025 0,02 0,015 0,01 0,005 0 0,01

0,1 1 10 100 Weighted Skeletal Dose, Gy

1000

Fig. 7.1  Sarcoma incidence in the cohort of “radium girls.” The female dial cohort was divided into 12 dose groups. Figure on the basis of R.E.  Rouland. Bone Sarcoma in Humans Induced by Radium: A Threshold Response? Environmental Research Division, Argonne National Laboratory, 1996

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Interest in the history of “radium girls” is still preserved. In 2018, the film company Cine Mosaic released the film “Radium Girls.” The film recreates the story of real girls painting clock faces with radioactive paint.

7.3 Experiments on Humans in the United States and USSR 7.3.1 Experiments on Humans in the United States The production of nuclear weapons requires plutonium-239. When work began on creating nuclear weapons in the 1940s, it was a completely new material, the radiobiological properties of which were unknown. It was expected that plutonium production would soon reach kilograms and then tons. It was clear that this would increase the pollution of workplaces. It was necessary to take care of the health of thousands of future nuclear workers. To solve the problem, a special research group was formed, whose task was to elucidate the radiobiological effects of exposure to plutonium. Experiments on animals, mainly on rats, have shown that the behavior of plutonium in the body differs significantly from that of radium, which is already familiar to scientists. Besides, it is tough to transfer to humans’ new results obtained in animals. However, time was rushing, plutonium production was growing, and the time for testing the first real atomic bomb was approaching. Therefore, the next step became inevitable—conducting experiments on humans. It should be noted that experiments with plutonium on living people, realizing their necessity, were supported by several leading physicists, in particular, the head of the Manhattan Project, Robert Oppenheimer, as well as the future Nobel Prize winner (1951), the man who discovered ten new elements of the periodic table, including plutonium, Glen Seaborg. For the experiments, a group of patients was selected from those diagnosed with “end-stage cancer.” However, obtaining reliable data on the metabolism of plutonium in the body required that patients have healthy livers and kidneys. The patients were unaware of the experiment, the plutonium was classified, and it was forbidden to mention its name. By the way, about secrecy. Even before the experiments with plutonium, five patients were injected with polonium (from August to November 1944), the same one that had recently poisoned Litvinenko. The mention of

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polonium was not then secret, it could be called to patients, and experiments with polonium were carried out on volunteers. However, it soon became apparent that fuses for atomic bombs should be made from polonium. The mention of polonium was classified, but only in July 1945, after the experiments with people, so the experiments with the injection of polonium did not make such a fuss as the subsequent experiments with plutonium. A total of 18 experiments were carried out with plutonium. Although plutonium injections into humans were performed for the first time, experts assumed these experiments were safe. Based on the experiments with radium, the investigators believed that the amount of material injected was minimal, and therefore, no immediate adverse reactions were expected. And they really did not exist. There was a danger of long-term effects, 10–20 years after the injection, as was observed in the “radium girls.” However, since people with an expected short life expectancy were selected as patients, the long-term consequences would have needed more time to manifest themselves. Among the patients were 12 men aged 36 to 68, 5 women—from 18 to 59 years, and one 10-month-old boy. Six people died within a year after the injection, and two more lived for over a year. Ten people turned out to be long-livers and, therefore, carrying plutonium in themselves for a long time. One of them lived after the injection for 44 years; at the time of the experiment, he was 36  years old. Two more lived after the experience of 37 and 38 years. The most famous patient in plutonium experiments is the carpenter Albert Stevens. His initial diagnosis turned out to be erroneous; he did not have stomach cancer but simply an ulcer. Stevens lived after the injection for 21 years, and all this time, the plutonium deposited in the bones created a dose of ~3.1  Sv per year. Over the course of his lifetime, Stevens received approximately 64 Sv. This is one of the largest doses received by any of the inhabitants of the planet Earth. After the classification was removed, information about plutonium experiments was published but unknown to the general public. In 1994, journalist Eileen Welsome unearthed the story from little-known declassified documents and personal contacts with experiment participants. The results of her research were published as a separate book, “The Plutonium Files. America’s Secret Medical Experiments in the Cold War,” which won the Pulitzer Prize. In the wake of public interest in the problem of inhuman experiments, President Bill Clinton, in January 1994, announced the creation of the Advisory Committee on Human Radiation Experiments (ACHRE).

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The committee dealt with human radiation experiments conducted from 1944 to 1974. The time frame was determined by the fact that the first experiments were planned in 1944, and in 1974, the Department of Health, Education and Welfare adopted rules for researching humans. Renowned biomedical ethicist Professor Ruth Faden chaired the committee (ACHRE). The final report of the Committee is over a thousand pages long and is easily accessible on the Internet. Experiments with plutonium turned out to be the most famous radiation experiments on humans. However, the matter was far from limited to them. The ACHRE database contains information on approximately 4000 such experiments, but this is not all. Many other radiation experiments are described in the author’s book “Radiation: Fundamental, Application, Risks and Safety” Elsevier, 2019 and in “The Effect of Radiation on Human Health,” Intellect, 2018 (in Russian). There were experiments in the United States on prisoners and mentally retarded students of the Fernald and Wrentham State schools, which are under the patronage of the Massachusetts Institute of Technology, the famous MIT. The main purpose of these experiments is the direct measurement of the biological effects of radioactive substances, the measurement of doses from radioactive substances introduced into the body by injection, with food, by breathing, or applied to the skin, the measurement of the time during which radioactive substances pass through the body, i.e., the so-called half-life. It was also assumed that it would be possible to determine the ability of the organism to recover after irradiation and, in some cases, to find methods of protection against the harmful effects of irradiation. At the dawn of the atomic age, the advent of nuclear reactors and the possibility of producing a variety of radioactive nuclides created the illusion of wonderful new possibilities, mainly in diagnostics and therapy. The dramatic advances in medical technology brought about by radionuclides have been compared with the advances that arose simultaneously associated with penicillin. However, experiments were required to find out the possibilities of using isotopes. Of course, radiation experiments on humans are immoral, but these are experiments with small doses and no data of severe consequences have been reported.

7.3.2 Experiments on Humans in the USSR Above, we talked about radiation experiments on humans in the United States. There is no doubt that similar experiments were carried out in the

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USSR and for the same reasons as in the United States. Knowledge of the behavior of plutonium and other radionuclides in the body is necessary to preserve thousands of people’s health. However, information about such experiments is still classified. So far, only military exercises using nuclear weapons at the Totsk test site and in Kazakhstan, when the soldiers were driven to the epicenter area shortly after the explosion, are summed up under the rubric of radiation experiments on people. The same column also includes the work of prisoners in uranium mines. There is no information about any injections, forced irradiation, or introducing radioactive substances into the body. More precisely, there are rumors, suspicions, indirect conclusions, etc. Nothing like, for example, the ACHRE report appeared either in the USSR or later in Russia. According to Russian historian Zhores Medvedev, “The secret of the fate of millions of people who made the most challenging contribution to the creation of the atomic power of a superpower remains unsolved … Only one thing is clear—the atomic Gulag claimed many more lives than the first atomic bombs dropped on Hiroshima and Nagasaki.” If this estimate is exaggerated, it is not by much. In the few memoirs that have come down to us about the mortality of the builders of atomic objects, it is only said that it “acquired enormous proportions.” Yakov Ladyzhensky, one of the researchers in the history of the Gulag, writes, for example, that his library contains about 400 books of camp memoirs, but “I didn’t come across any notes from those who worked at nuclear facilities and survived. Kolyma—in bulk, Vorkuta and Dzhezkazgan—please, but no one from Krasnoyarsk-26.” Krasnoyarsk-26 is now the city of Zheleznogorsk. Most likely, radiation experiments on people were carried out in the USSR somewhere in the other closed towns or even in the central regions, maybe in Moscow. Russian Professor Vasiliy Vlassov, in the paper “Russian Medicine and the Nuremberg Trials,” published in 2006, wrote: “We know something about human radiation experiments in the USA and the UK, but we know nothing about similar experiments in the USSR. After the Perestroika, we learned that Soviet physicians for decades secretly studied the health of people living in an area in the South Ural contaminated by radioactive wastes after a nuclear disaster. We learned from witnesses that the Soviet state used prisoners and military personnel to test lethal toxins and other weapons. We may be sure the Soviet state experimented with radiation on human subjects. But probably, we never will learn the truth.”

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7.4 Victims of the Atomic Bombardment of Hiroshima and Nagasaki 7.4.1 Atomic Bombardment Although the effects of radiation on humans have been studied for more than a hundred years and a large number of cohorts have formed that, for one reason or another, received excess exposure compared to background exposure, the most detailed and important, with the longest history of observations, providing perhaps the richest information, are still studies of the consequences of nuclear explosions in Hiroshima and Nagasaki. In 1945, during the Second World War, the United States dropped atomic bombs on Japanese cities, the first two, and so far, fortunately, the last atomic bombs were used for the actual bombing of populated cities. The destructive effects of a nuclear explosion are described in Sect. 4.5.1, which deals with the role of nuclear bombing and nuclear testing in forming radiophobia. Here, we focus on the effects of radiation. Before the atomic bombing, the population of Hiroshima was approximately 330 thousand people, and Nagasaki—280 thousand. The bomb dropped on Hiroshima immediately killed 90 to 120 thousand people, wounded about 100 thousand, and caused extensive destruction in the city. In Nagasaki, 60–80 thousand people died from the explosion. The exact number of victims is still unknown. Residents of Hiroshima and Nagasaki who survived the bombing were given the collective name “hibakusha,” which translates from Japanese as “people exposed to the explosion.” The Japanese government has recognized approximately 650,000 people as eligible to wear the title of hibakusha. Officially recognized hibakusha have certain advantages: cash benefits, exceptional medical care, etc. Those closest to the explosion’s epicenter died instantly; their bodies turned to coal or, as some articles say, almost evaporated. Many of the bodies were swept out to sea after those dying of burns were thrown into the numerous rivers of Hiroshima. By the way, this explains why there is still no information about the exact number of victims. In the first days and even months after the bombing, the necessary instruments and tools were missing, most of the institutions, including medical ones, were destroyed, and qualified medical and technical personnel suffered the same way as the entire population. The first radiation measurements were made by the US Army after the end of the war and were classified. With a

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long delay, the early studies of Japanese scientists became known and included in scientific circulation. On October 1, 1950, the formation of a cohort of survivors of the atomic bombing and work under the Life Span Study (LSS) program began. Among the survivors of the bombing, a cohort of approximately 120 thousand people was selected. It included 93 thousand who were in Hiroshima or Nagasaki at the time of the bombings, and for comparison, 27 thousand who lived in these cities at the time the cohort was compiled (~ 1950) but were absent at the time of the bombing. The survey also included 77 thousand descendants born between 1946 and 1984 whose father, mother, or both survived the bombing. In the future, other people were also involved in the study, so that as a result of a long examination, about half of all those who survived the bombing were subjected to a long examination. Significantly, the cohorts began to form with a significant time shift relative to the time of the bombardment, so information about the effects of radiation in the first years after the explosion is largely lost.

7.4.2 Doses Those who received large doses were relatively few; according to physicians and biologists from the Radiation Effects Research Foundation (RERF), approximately 2200 people from a cohort of 105,427 people received doses above the radiation sickness threshold, i.e., more than 1 Sv. Doses in the interval between the threshold of radiation sickness (~1 Sv) and the threshold of stochastic effects (~0.1 Sv) were received by ~14 thousand people. About 89 thousand remained beyond the threshold of stochastic effects. For a selected cohort, it was necessary to determine the doses each irradiated received and monitor their health. We remember that the main consequence of low-dose irradiation is cancer, which has a long latent period—tens of years. So, you have to follow for a long time; observations continue to the present, and not all the inhabitants of Hiroshima or Nagasaki in 1945 have passed away. Keeping track of the health of tens of thousands of people is a huge task, but it is clear how to carry it out. With doses, the situation is much more complicated. The problem with doses has not been solved to date. The surveys began with a long delay; it was necessary to determine the doses received due to the bombardment retrospectively. The radiation to which the victims of the bombing were exposed came from two sources. The main radiation is gamma quanta and neutrons of the explosion itself; it acted for about 30 s. Hiroshima is located on a plain, and it was assumed that the

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doses were distributed concentrically in open space with respect to the epicenter. The further, the lower the dose. This distribution is shown in Fig. 7.2. It can be seen from the figure that as the radius increases, the dose decreases, and the ring area increases so that the smaller the dose, the more people are exposed to the corresponding dose of radiation. The situation is somewhat more complicated in Nagasaki, but more on that later. The members of the cohorts were interviewed, and their position during the bombardment was recorded. This position is shown by dots in Fig. 7.2. The dose from an explosion depends on the distance to the epicenter where the irradiated person was located, the shielding conditions, and the body’s position during the explosion.

Fig. 7.2  Distribution of the absorbed dose around the epicenter during the bombing of Hiroshima. Circles show distances of 2 and 3  km from the epicenter. The colored areas are made up of dots, each dot representing a person who survived the bombing. Gray dots in the central part—doses unknown, red dots—doses greater than 1  Gy, orange—0.5–1 Gy, yellow—0.2–0.5 Gy, brown—5–100 mGy, pink—less than 5 mGy. It can be seen that the doses are distributed more or less concentrically. Figure from Douple, E. B., K. Mabuchi, H. M. Cullings, D. L. Preston, K. Kodama, et al., 2011 Long-­ term radiation-related health effects in a unique human population: lessons learned from the atomic bomb survivors of Hiroshima and Nagasaki. Disaster Med. Public Health Prep. 5 (Suppl 1): S122–S133, Fig. 2—https://www.ncbi.nlm.nih.gov/pmc/articles/ PMC3907953/. With permission from Cambridge University Press

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To determine radiation shielding for indoor occupants, several typical Japanese houses were built in the United States at a test site in Nevada. The conditions of the Hiroshima and Nagasaki bombings were simulated. They did not manage to complete the measurements before the prohibition of testing nuclear weapons in the atmosphere in 1963, and then, a tower was built at the test site; sources of both gamma and neutron radiation were installed on the tower, not as intense as in the explosion cloud, but nevertheless, they made it possible to determine the role of shielding. Estimates of individual doses were carried out several times, each time more and more accurately, but in all cases, the basis for determining doses was the distance from the epicenter, considering shielding by building materials. Approximately half an hour after the explosion, precipitation, called “black rain,” fell in both cities. The precipitation consisted of grains of sand, dust particles, and ash raised from the surface of the earth by an explosion and adsorbing on its surface radioactive fission products of plutonium or uranium, as well as radioactive nuclides formed as a result of the action of neutrons on the soil (induced activity). These precipitations also led to the population’s exposure, gradually weakening for several days. Additional exposure from fallout was not considered for a long time, although reports of significant radioactive contamination appeared long ago. So, in 1957, Dr. Gensaku Obo published an article in a little-known medical journal in Japanese, which went unnoticed. In 2017, this article was discovered and published by Shizuyo Sutou. The article clearly indicated that at a considerable distance around the epicenter of the explosion in Hiroshima, there was a vast area of radioactive contamination, much larger than previously thought, and that people who entered this zone for several days after the explosion and remained there for several hours showed typical signs of radiation injury. It is impossible to separate radiation damage from the explosion and precipitation in the Hiroshima case. The map of the precipitation is presented in Fig. 7.3. A somewhat different situation developed in Nagasaki. Nagasaki is a hilly city, which is one of the reasons why fewer people were killed in the bombing in this city than in Hiroshima, although the bomb for Nagasaki was noticeably more powerful. In addition, the bomb did not explode over the city center but over an industrial area. After the explosion, a cloud containing radioactive dust and ash was formed, which moved with the wind in an easterly direction. Radioactive fallout fell out of it over the Nishiyama area. This area, located east of the center, is shielded from the direct radiation of the explosion by the 366 m high Kompira Hill. Thus, the inhabitants of Nishiyama were not exposed to instantaneous radiation from the explosion but

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Fig. 7.3  Distribution of radiation contamination due to black rain. The map was made shortly after the explosion by a team of meteorologists led by Uda Michitaka. The central (brown) area is a zone of strong infection (“heavy rain area”), the beige area is a zone of weaker infection, and the gray area is an extended infection zone. Only residents of the severely infected zone received the status of hibakusha, which gives certain benefits. Figure from Fight for Recognition: The Long Ordeal of “Black Rain” Survivors. Aug 4, 2020—https://www.nippon.com/en/japan-­topics/c08202/. With permission from Nippon.com

experienced long-term exposure to radioactive contamination of the area due to fallout. The special position of the Nishiyama area was noticed shortly after the bombing. The dosimetry and health status of Nishiyama residents have resulted from several studies. By the time of this writing, the latest was conducted by Nagasaki University biologists Kenichi Yokota and co-workers and published in 2018. In Nishiyama, residents were exposed only to fallout; the association of diseases with radiation exposure could not be identified. According to various estimates, precipitation added an average of 20 mGy to the external radiation dose in Hiroshima and up to 300 mGy in Nagasaki.

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This is a small supplement for radiation sickness, but it is quite significant for long-term consequences. According to many Japanese researchers, the doses received by the population of both Japanese cities are underestimated; the real doses were greater than those that appear in many official documents. This means that all the dose-effect dependencies constructed earlier should be shifted to the right, toward large doses, reducing the danger of small doses. As a result of the explosions, residents of both cities within 1.5 km from the epicenter died, mainly from the shock wave and the thermal effect of the explosion, were buried or burned in destroyed buildings, and flying fragments of glass or other debris could injure them. The bodily displacement and missile hazard created by the blast wind causes most injury and death, not the overpressure itself. Numerous small fires that simultaneously arose in Hiroshima soon merged into one large fire tornado, creating a strong wind toward the epicenter. A fire tornado took over the city center, killing everyone who did not have time to get out within the first few minutes after the explosion. It is tough to determine what proportion of dead people have received a lethal dose of radiation to separate radiation damage from burns, injuries, and infections. The role of radiation as a negative factor in a nuclear explosion is greatly overestimated. Of course, at a short distance from the epicenter, the doses may be sufficient to cause radiation sickness or even kill. However, in this area, the blast wave is more substantial. Both the blast wave and the radiation weaken with distance from the epicenter, but the radiation weakens faster. However, the radiation will arrive earlier. Gamma radiation from a nuclear explosion propagates at the speed of light and, for example, it will fly 1 km in ~3 microseconds, an explosive wave that will tear apart a body burned by gamma radiation will take ~1.5 s. The fact that radiation decays faster with distance than other damaging factors is illustrated in Fig. 7.4, which shows the results of measurements and calculations of change of thermal energy, blast wind velocity, and gamma and neutron radiation doses depending on the distance from the epicenter for a nuclear explosion with a power of ~20 kt at an altitude of ~500 m.

7.4.3 Health Already the first reports of the aftermath of the bombing showed that survivors of the explosion were showing previously unknown symptoms. The first

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Blast wind velocity

Relative values

0,1 Thermal energy

0,01

Doses from gamma

0,001 Doses from neutrons

0,0001 0,00001 0

1 2 Distance from hypocenter, km

3

Fig. 7.4  Decreasing of blast wind velocity, thermal energy, and radiation doses from gamma and neutrons depending on the distance from epicenter for an explosion with a power of ~20 kt at an altitude of ~500 m. Values are presented relative to the maximum values at the epicenter. To evaluate the real picture, we point out that in the case of this graph, gamma dose at the distance of 1 km is 7.8 Gy and the neutron dose is ~0.14 Gy. At this distance, the speed of the blast wave is ~550 km/h (yet more than the speed of sound), and the intensity of thermal energy is ~20 W/cm2 (maximum intensity of sunlight is 0.14  W/cm2). On the basis of the US Army Manhattan Project Team (Atomic Bomb Disease Institute, Nagasaki University 1995), published by M. Tomonaga. The Atomic Bombing of Hiroshima and Nagasaki: A Summary of the Human Consequences, 1945–2018, and Lessons for Homo sapiens to End the Nuclear Weapon Age. Journal for Peace and Nuclear Disarmament, 2 (2) 491–517, 2019, Figs. 4, 5, and 6.—https://www.tandfonline.com/doi/full/10.1080/25751654.2019.1681226

victims of the explosion were people who were injured and burned. After a while, those who seemed to be getting better began to develop unfamiliar symptoms of a new strange disease. Humankind first encountered a phenomenon later called “acute radiation sickness.” Deaths from acute radiation sickness peaked 3–4  weeks after the explosion and began to decline only after 7–8 weeks. And three years after the bombing, in 1948, cases of leukemia began to rise. Dr. Fumio Shigeto drew attention to this. It is estimated (no exact data for the initial period) that leukemia peaked in 1953 and then the number of cases began to decline. Since the bombing, approximately 300 people out of a cohort of 100,000 have died of leukemia. A little later, since 1955, the frequency of ordinary solid cancers began to increase clearly. The time distribution after the nuclear bombardment of the number of deaths from leukemia and solid cancers, according to the Japanese cohort Masao Tomonaga, is shown in Fig. 7.5. Similar graphics walkthrough articles, books, and websites describing the consequences of the atomic bombing. In most cases, the curve for solid

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Mortality

Solid cancer

Leukemia 0

10

20

30

40

50

60 68

Years after 1945

Fig. 7.5  Distribution in time after the nuclear bombardment of the number of deaths from leukemia and from solid cancers. Figure on the basis of M. Tomonaga. The Atomic Bombings of Hiroshima and Nagasaki: A Summary of the Human Consequences, 1945–2018, and Lessons for Homo sapiens to End the Nuclear Weapon Age. J. for Peace and Nuclear Disarmament, 2 (2) 2019, 491–517—https://www.tandfonline.com/doi/ful l/10.1080/25751654.2019.1681226

cancers is drawn through a maximum by analogy with the curve for leukemia. However, reliable data for long periods are still scarce. Because of this, the area near the maximum and behind it is shown with a dotted line (Fig. 6.6). In some papers, it is believed that the maximum is reached after 40 years, sometimes after 60. However, in the graph presented by Dr. Tomonaga, the number of new cancer cases in about 2000 reached a plateau, and until 2018, the year of writing, when the average age of victims of the bombing reached 82 years old, did not change. The result is a little strange; at some point, the curve should start to fall, and the number of new cancers will become zero when the last survivor of the bombing dies, but there is still time. In March 2020 (75  years after the bombing), almost 140 thousand hibakushas were still alive. However, the difference between the curves in Figs.  7.5 and 6.6 can be explained in different ways of calculation. The health of the survivors of the bombing has been closely monitored for more than 75 years. The huge number of exposed people and the duration and detail of the studies made it possible to obtain extensive, well-statistically supported information on the effects of radiation. The dependence of the state of health of the exposed on gender, age at exposure, living conditions, subsequent medical efforts, and much more is subjected to a detailed analysis. In the case of irradiation during the bombardment, the entire body was exposed almost evenly. Therefore, obtaining extensive information about which organs are affected with what probability is possible. From the vast collection of accumulated information, let us single out the most important in the context of this book.

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Out of a cohort of more than 100,000 people, slightly more than 300 died from leukemia and about 2500 died from solid cancers. The average decrease in life expectancy due to cancer in individuals who received a dose of 0.005–1 Gy is about two months and for those who received a dose of 1  Gy or more—about 2.6  years. The proportion of deaths from cancer is weakly dependent on the dose up to a dose of ~0.2  Sv. The best threshold estimates for the induction of stochastic effects give a value of the order of 0.12 Sv. In March 2020 (75 years after the bombing), 136,682 people (~21%) were still alive; their average age was 83.3 years. Recently, a detailed description of the consequences of the atomic bombings was published by Masao Tomonaga. Dr. Tomonaga was born in 1943 in Nagasaki and experienced all the consequences of the bombing in his childhood, i.e., he became a “hibakusha.” He is currently the honorary director of the Red Cross Atomic Hospital in Nagasaki. The minimum dose at which cancer cases have been observed, according to Dr. Tomonaga, is ~100 mSv. Survivors of the bombing have a fairly large number of non-cancerous diseases associated with radiation. Estimates show that at doses of the order of 1 Sv of all deaths from radiation, cancer is responsible for approximately 60% of deaths, non-cancer diseases for 30%, and leukemia for 10%.

7.4.4 Genetic Consequences Observing a cohort of children born to exposed parents is of great interest. Due to the large cohort size (~77,000) and long-term follow-up (several decades), the data obtained should allow the assessment of measurable genetic defects. It should be noted that among the survivors of the bombing, there were about 3600 pregnant women. Children irradiated in the womb showed obvious developmental problems, mental disability, and neurological effects. However, the children conceived after the bombing showed no radiation-­ related pathology. Also, no malformations of intrauterine development were found. Moreover, all attempts to identify an increased number of mutations have had a negative result.

7.4.5 Hibakusha Twice Interestingly, among the people who fell under the atomic bombing, there were quite a few people who survived both—both in Hiroshima and in

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Nagasaki. The producers, who were going to make a film about them, found 165 such “lucky ones.” R. Trumbull’s book “The Nine Survivors of Hiroshima and Nagasaki” describes the story of nine such twice hibakushas. Perhaps the most famous of them is Tsutomu Yamaguchi. It was not until March 2009 that the Japanese government officially recognized him as a survivor of both bombings. He lived a relatively prosperous life, although not without sores, and died of stomach cancer in 2010 at 93. His wife also suffered an atomic bombing, though only one—in Nagasaki and died in the same year as her husband, at the same age. They had three children. The question is—was he twice unlucky or, on the contrary, twice lucky? As in many other cases, bad luck is confused with luck. One got irradiated—no luck, stayed alive—lucky.

7.4.6 Conventional Bombardment Two nuclear bombs dropped on Japanese cities are recognized as barbaric, but there is much less public outrage about the deaths of people during the conventional bombing. The results of the bombing of Dresden, Hamburg, Berlin in Germany, and Tokyo in Japan with conventional bombs during the Second World War can compete with the defeat from nuclear charges (in the number of people killed and destroyed buildings). On March 10, 1945, three groups of American bombers that took off from the island of Tinian in the Pacific Ocean, 334  in total, bombarded Tokyo. Several tens of tons of high-explosive and incendiary bombs were dropped on the capital of the Japanese Empire, which led to the death of over one hundred thousand people (more than during the atomic bombing of Nagasaki), as well as to the destruction of 40% of the city’s residential buildings and the most important strategic objects. For three days on February 13–15, 1945, American and British planes (Americans, as a rule, during the day, British—at night) dropped about 4 kt of high-explosive and incendiary bombs on the German city of Dresden. The area of the zone of continuous destruction in Dresden was four times larger than that in Nagasaki. Estimates of the number of dead varied from 25,000 in official German wartime reports to 200,000 and even 500,000. The massive bombing of Hamburg occurred on July 25–August 3, 1943. The bombing on the night of July 28 was especially destructive. Special weather conditions and the intensity of the bombing led to the formation of a fiery tornado; the temperature rose to 600 °C. At this temperature, ignition did not require contact with a flame. The heat was enough. Everything made

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of paper, fabric, and wood burned; aluminum and lead became liquid; steel became plastic and deformed, unable to withstand structural loads. The bricks slowly softened, transforming under their weight like clay, and the buildings collapsed. In total, up to 45 thousand people died from the bombing, and about 40 thousand on that terrible night on 28. Most of the dead were poisoned by combustion products. During the bombing of Berlin, a total of 540 kt of bombs were dropped, while at least 52 thousand people died, and twice as many were seriously injured. Actually, to achieve a result similar to the explosion of a single nuclear bomb, hundreds of sorties with conventional bombs were required. In the matter of destruction, humanity has made a giant leap forward (only forward?).

7.5 Radiologists and Patients 7.5.1 Radiologists Currently, radiation medicine is the most extensive area of human activity in which people are exposed to ionizing radiation. According to the US National Council on Radiation Protection and Measurement (NCRP), in 2006, about 7 million people were employed worldwide in providing various radiation procedures (~33% of all workers exposed to radiation), 2.5 million of whom are in the United States. This is more than the number of people working in all stages of the nuclear fuel cycle, industrial uses of radiation, and defense activities combined. More people are exposed to radiation in medical procedures. Average doses received by patients from radiation procedures are continuously rising in the United States from 1980 to 2006, doses increased more than seven times. Detailed epidemiological studies of the relationship between the health of radiologists and exposure began after World War II, in the 1950s. At the same time, the incidence of cancer and mortality of radiologists and radiation technicians were analyzed, starting from the 1920s. The studies concerned many cohorts in different countries, with a total number of hundreds of thousands of people. Briefly, the overall result of the research is as follows. Among radiologists who worked before 1950, lung cancer and leukemia risk increased statistically significantly. Understanding the problem and improving the technique have made it possible over the years to reduce doses and risks substantially. Average annual doses, ~70 mSv/year before 1939, have fallen to ~2 mSv/

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year in the late 1970s and are less than ~1  mSv/year today. The results of studies that included radiologists after the 1950s, when exposures decreased and more reliable methods of protection and control were introduced, showed that none of the types of cancer showed an additional risk. The work of radiologists has become practically safe.

7.5.2 Patients Patients are exposed to radiation in two cases: in diagnostic procedures, the vast majority, in civilized countries, it is almost the entire population, and in the treatment of malignant tumors, only a few are not lucky. Radiation diagnostics and radiation therapy fundamentally differ in their approach to the problem of exposure doses and their consequences. In radiation diagnostics, all measures are taken to reduce the radiation load on the patient. Generally, radiation in medicine is permissible when it does better than harm. In radiation therapy, exposure of a person is intentional, and the ability of the radiation to kill cells is the very purpose of the treatment. All protective measures in radiation therapy come down to reducing the effects of radiation on healthy tissues. The most common diagnostic procedures, fluorography and radiography, produce low doses and are entirely safe. Radiation in simple diagnostic procedures does not increase the risk of tumors. Such procedures are safe not only according to objective indicators but also in public opinion. Usually, patients go through such a procedure without resistance. However, in a wide range of different options for radiation diagnostics, there are those that, even in single studies, create a very significant dose, particularly the very popular computed tomography. Large doses are created during angiography, during interventional procedures such as angioplasty, arthroplasty, biopsy, and others. For example, a stent is inserted into the pericardial vessel through the femoral artery under X-ray guidance. This procedure can take up to an hour and sometimes even longer. The doses from these procedures fall within the range that, in principle, could carry an increased risk of subsequent cancer. Another suspected source of danger is multiple procedures, regularly repeated X-ray examinations of tuberculosis patients, patients with scoliosis, and other bone diseases. Although the single doses of a conventional X-ray procedure are small, multiple pulmonological or orthopedic examinations can generate significant doses. Thus, in a group of 4940 women undergoing

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Table 7.1  Typical effective doses in diagnostic procedures Diagnostic procedure

Typical effective dose (mSv)

Digital fluoroscopy Chest X-ray Mammography X-ray of the gastrointestinal tract with a barium enema Dental X-ray Computer tomography (CT scan): Skull, head Chest organs, kidneys, liver Of the whole body Radionuclide investigations Angiography Interventional procedures, angioplasty, arthroplasty, biopsy

0.03–0.06 (low-dose devices 0.002) 0.15–0.40 1–3 15 0.15–0.35 (low-dose devices 0.1) 1–2 6–11 45 2–15 10–200 10–300

regular fluorographic examinations, the average number of procedures was 88, and the total average dose accumulated over 22 years of examinations was about 0.79 Sv. Typical dose values for medical diagnostic procedures are given in Table 7.1. Many studies of various cohorts have shown the safety of rare procedures and some usefulness of multiple procedures. In a cohort study of 64,172 patients with tuberculosis in Canada undergoing routine chest X-ray examinations, no association of lung cancer risk with radiation dose was found.

7.6 Chernobyl: Liquidators and Population 7.6.1 Accident On April 26, 1986, at 01:23:47, due to personnel errors and design flaws, the reactor of the fourth power unit of the Chernobyl nuclear power plant exploded, the Chernobyl disaster occurred the highest, the seventh level of danger. By the time of the explosion, the reactor had been operating at full power for about three years. This means that many radioactive nuclides have accumulated in the reactor’s fuel elements. At the time of the accident, the reactor contained 192 tons of uranium and its decay products and 1760 tons of graphite that had become radioactive, which acted as a neutron moderator in the reactor.

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As a result of a thermal explosion and the subsequent burning of graphite, a large amount of nuclear fuel and graphite was ejected from the core. The nuclear fuel remaining in the reactor in molten form, having mixed with molten structural materials, spread throughout the premises and leaked into the lower floors. Disputes about the amount of nuclear fuel thrown out still need to subside, and estimates differ many times. According to data that can be considered official, which appears in many papers and reports, about 3–5% of the fuel was released from the reactor into the environment, i.e., ~ 7–10 tons. However, in a study by employees of the Kurchatov Institute, based on a visual inspection of the ruins and published in the journal “Atomic Energy,” it was suggested that only ~10% of the fuel could remain in the destroyed premises; the rest was thrown away. The question of how much, in what form, and where radioactive substances were released is extremely important. The quantity, type, and distribution of evaporated or dispersed radionuclides determine the radiation background. The background, in turn, determines the doses that affect both wildlife and people, and the doses determine the health of people exposed to radiation. It turns out such a consistent chain of causes and effects. To date, a large number of scientific articles have been published, reviews of which are given in official publications: the International Atomic Energy Agency (IAEA), the World Health Organization (WHO), the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), the International Commission on Radiological Protection (ICRP), etc. The release of radioactive substances occurred not only at the moment of the explosion but continued for a long time after it. The emission activity at the Chernobyl nuclear power plant in the first five days after the accident slowly decreased. Still, starting May 2, it rose sharply, acquiring a threateningly growing character due to overheating fuel by decay heat. Backfilling of the ruins of the reactor from helicopters made it possible to stop this growth. Nevertheless, the ruins continued to gather dust even after that. Emissions significantly decreased after constructing a protective shelter, the so-called “Sarcophagus.” However, this structure was built in a hurry; there were many gaps in it, and the shelter was slowly destroyed. At the end of November 2016, the emergency reactor with the old sarcophagus was covered with a new movable protective arch. The New Safe Confinement (NSC) was finally commissioned on July 10, 2019. The destroyed reactor and the new sarcophagus are shown in Fig. 7.6. During the first 24  h, about 600 people took part in emergency work directly on the spot, including station personnel, firefighters, security officers,

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The destroyed reactor of the 4th power unit

A new sarcophagus

Fig. 7.6  The fourth power unit of the Chernobyl nuclear power plant. (a, b) Both figures are from The EBRD’s mission in Chernobyl. European Bank for Reconstruction and Development.—https://www.ebrd.com/ebrds-­mission-­in-­chernobyl-­gallery.html. With permission from EBRD

and personnel of the local medical institution. In the early days, everyone who took part in eliminating the danger of new explosions and reducing the activity of emissions received large doses. Radiation in large doses showed its harmful character. Acute radiation sickness (ARS) symptoms were initially suspected in 237 patients. Later, this diagnosis was confirmed only in 134 people. Of these, 28 people died from ARS by the end of 1986. Directly during the accident, three Chernobyl nuclear power plant employees died for reasons unrelated to radiation. In subsequent years (1987–2004), another 19 people died from radiation sickness. It is believed that radiation burns of the skin played a significant role in the death of the first ARS patients, exacerbating other factors. The skin doses from beta radiation in some patients with acute radiation sickness were 10 to 30 times greater than the whole-body doses from external radiation. Many ARS patients received crazy skin doses in the 400–500 Sv range. The well-known journalist and public figure Alla Yaroshinskaya in 1991, at that time a deputy of the Supreme Soviet of the USSR, managed to get access to the minutes of the meetings of the task force of the Politburo of the Central Committee of the CPSU, headed by the then Chairman of the Council of Ministers N.I. Ryzhkov. An almost detective story about how copies of these protocols were obtained is described by Yaroshinskaya in her book “Chernobyl. Big Lies” in Chap. 15, “Forty Secret Protocols of the Kremlin Wise Men.” From the beginning of May to the beginning of June, the number of hospitalized patients, including those with signs of radiation sickness, is noted in the protocols almost daily. For example, protocol No. 12, dated May 12, 1986, states: “Over the past day, 2,703 people were hospitalized, mainly from Belarus. 10,198 people are

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undergoing inpatient examination and treatment, of which 345 people have signs of radiation sickness. Among them, 35 children.” The given figures are much more than those that appear in the reports, which we call “official.” It is believed that the main stage of liquidation of the consequences of the accident lasted 3  years (1986–1989). In the aftermath of the accident in 1986–87, about 440 thousand people participated. In the future, their number will increase to more than 500 thousand. These people are called liquidators. Approximately 200 thousand people worked in the 30-km zone. It should be noted that the number of liquidators included not only workers, engineers, scientists, and military personnel who actually dealt with the elimination of the consequences of the accident but also everyone who worked in the contaminated territories, in particular, doctors, teachers, cooks, translators, etc. In total, 1125 pilots and members of the helicopter team and 672 employees of the Kurchatov Institute took part in emergency work. Both the liquidators and the public were exposed to external exposure from radionuclides released from the reactor and internal exposure to food, water, and air containing radionuclides. These were the conditions of long-term, so-­ called chronic exposure.

7.6.2 Terrain Pollution The main impact on both the population and the liquidators was exerted by two environmentally significant radionuclides—the short-lived nuclide iodine-131, which determined the impact on health in the first couple of months because it has a half-life of 8 days, and cesium-137 with a half-life of 30 years, whose effects are still ongoing. Both nuclides are beta and gamma emitters and can create both external and, if they get inside the body, then internal radiation. The share of these nuclides in the release was ~20%. It is known that strontium-90 is considered one of the most dangerous radionuclides, the most important for assessing the impact on health. During the Chernobyl accident, the role of this nuclide was small since its volatility determines the proportion of the emitted nuclides. Almost completely emitted radioactive gases—krypton-85 and xenon-133, to a lesser extent—the most volatile substances—isotopes of iodine, tellurium, and cesium. Strontium is less volatile, and its release was relatively small. The wind carried dispersed radioactive substances and fine particles in the composition of emissions and fell mainly with rain over a large area. The territories of some regions of Ukraine, Belarus, and Russia were mainly

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contaminated, but trace concentrations of radionuclides could be found in almost all countries of the Northern Hemisphere. The contamination of the area determines the dose rate of external radiation. When determining the fallout risk, surface activity boundary values were established. For cesium-137 contamination, the lower limit is 37  kBq/m2 (1  Ci/km2). Economic working can be carried out on lands with activity below the specified value. The value (for cesium-137) 555  kBq/m2 (15  Ci/km2) was taken as the upper limit value of pollution. The population must be resettled from areas with a fallout density above the upper limit value. Considering these norms, out of 188 settlements in the affected areas, 116 thousand people were evacuated in the spring and summer of 1986 and later about 220 thousand more had to be relocated. About 5 million people currently live in the contaminated territories of the former Soviet Union, with a total area of 150 thousand km2. Due to the rains during the passage of radioactive clouds, the fallout was highly uneven. In addition, some of the fallout consisted of nuclear fuel particles (so-called “hot” particles) with a high content of radionuclides. Such hot particles were distributed mainly about 20  km from the Chernobyl nuclear power plant. The radionuclides deposited on the ground are involved in the complex circulation processes of substances in nature. They are weathered, washed out, absorbed by plants, and then by animals, decay, etc. It is essential that all these diverse processes occur differently on agricultural lands, in forests, in water bodies, and in the urban environment. The migration of radionuclides in nature is studied in detail in many scientific institutions. However, the study of these processes has been going on for a long time since the first tests of nuclear weapons. If, in many cases, the introduction of radionuclides into the environment had to be done artificially, then in Chernobyl an accident did it for scientists.

7.6.3 Doses According to the data given in the UNSCEAR report, the average effective dose received by workers involved in the clean-up of the accident between 1986 and 1990, mainly due to external radiation, is now estimated at about 100 mSv. Recorded doses received by workers ranged from less than 10 mSv to more than 1000  mSv, although about 85 percent of the recorded doses

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were in the range of 20–500 mSv. Estimates of individual doses vary within relatively wide limits. The doses received by the population during the entire exposure period were significantly lower. According to UNSCEAR, the 6 million inhabitants of the territories of the former Soviet Union recognized as contaminated received an average effective dose to the whole body during the period 1986–2005 of about 9 mSv, with a third of this dose received in 1986. About three-quarters of the dose is due to external exposure and the rest is due to internal exposure. Of particular interest are the doses received by the thyroid gland. Because radioactive iodine accumulates in the small thyroid gland, its doses are very significant. They are associated almost exclusively with consuming fresh milk containing iodine-131 in the first few weeks after the accident. This was especially true for infants and children, who consume relatively more milk than adults. The thyroid dose for those evacuated while consuming fresh milk containing iodine-131 was estimated to range from 50 mSv to 5 Sv, with an average of about 500 mSv. The mean thyroid dose in preschool children was about 2 to 4 times greater than the mean dose in the general population. For the rest of the population of the affected regions of Belarus, Ukraine, and part of the Russian Federation, including the contaminated areas (a total of 98 million people), the average dose to the thyroid gland was much lower and amounted to about 20 mSv. The average dose to the thyroid gland for residents of other European countries was about 1.3 mSv.

7.6.4 Health We have already said above about the consequences of irradiating the victims of the Chernobyl accident with large doses; large doses are dangerous and lead to severe consequences. However, such victims were relatively few. The vast majority of the liquidators, and especially the population, received doses that could be classified as small or medium. In this case, with some delay, long-­ term consequences will appear. The main stochastic effects of radiation are two types of cancer: leukemia and solid (tumor) cancers. Development in time of various types of cancer is shown in Figs. 6.6, and 7.5. That is how, with a relatively short time delay (several years), the liquidators were found to have leukemia. During the first three years after the accident, about 5–7 cases per 100 thousand people per year were registered among the liquidators,

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corresponding to the spontaneous cancer incidence in the country’s male population. During 1992–1995, the incidence of leukemia liquidators approximately doubled and then began to decrease again, approaching the spontaneous level. To date, the maximum of leukemia has long been passed. The induction of new leukemias becomes practically zero after about 30 years of exposure. The strongest manifestation of the action of radiation was thyroid cancer. Contamination of milk with the radionuclide iodine-131 led to large doses to the thyroid gland by the population; this has been responsible for a large proportion of the thyroid cancer cases reported to date in people who were children at the time of the accident. By 2016, more than 11,000 cases of such cancers were diagnosed in this group among more than two million exposed to radioactive iodine, according to WHO.  Now we understand that these cases could have been much less if urgent protective measures had been taken in time: rapid evacuation and iodine prophylaxis, clear explanatory work. It should be noted that thyroid cancer is quite easily treated; after surgery, it practically does not relapse. It is known that only 15 of the patients died, and as indicated in the article by Ukrainian specialists A. Vaiserman and his co-­ workers, even these 15 lethal cases could be explained by surgical complications. A slight increase in the incidence of thyroid cancer was also found among the liquidators. Of the 55 cases found, 12 were attributed to exposure to radiation. The probability of any other type of cancer in victims of Chernobyl is much lower than thyroid cancer, but it must be borne in mind that other types of cancer are treated worse. Regarding thyroid cancer, many researchers note that some of the increase in the number of cancers may be due to the so-called overdiagnosis. Diagnostic procedures on “infected” and “clean” territories are carried out with significantly different intensities. With rarer examinations, some cases may have been missed. For example, when South Korea introduced screening procedures in 2000, a population-wide examination, the detection of thyroid cancer increased 15 times. In addition, it is noted that the upward trend in the incidence of thyroid cancer has been observed since 1970, i.e., long before the Chernobyl accident, and in particular, in areas far from the areas of radioactive fallout. Another obvious effect of radiation is the development of eye cataracts in some liquidators. So, the “official” reports information about a significant number of thyroid cancers in people who were children at the time of the accident, an

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insignificant number of leukemias, and cataracts in the liquidators. To characterize the state of health, I quote from “official” documents. According to an extensive epidemiological study led by renowned radiation epidemiologist E. Cardis, “Except for the significant increase in thyroid cancer incidence in children and young people, there was no increase in the incidence of other radiation-­associated solid cancers or leukemia, as well as nonmalignant disorders, was observed in the exposed population.” From the UNSCEAR report: “There does not seem to be evidence at this time to unambiguously indicate any measurable increase in the incidence of all types of solid cancers in the populations of the Russian Federation and Ukraine.” “Although several hundred thousand people were involved in the aftermath of the accident, to date, apart from indications of an increase in the incidence of leukemia and the development of cataracts among those receiving increased doses, there is no evidence of health effects that could be attributed to exposure to radiation.”

7.6.5 Psychological Trauma of the Population Most researchers and experts pay attention to the fact that a huge role in the deterioration of the health of millions of people in the Chernobyl disaster zone was played not by radiation but by a significant change in living conditions. Forced evacuation, restrictions in the usual activities, and conflicting information about the possible consequences of the accident radically changed the way of life of these people and led to psychological discomfort. The general morbidity of the adult population living in contaminated territories significantly exceeds the national average. However, in the vast majority of cases, the causes of the disease cannot be attributed to the effects of radiation. The psychological trauma from the events of the accident arose not because of the radiation itself but because of the fear of radiation. Here, radiophobia manifested itself in full force. It is known from the psychology of perception that the absence of a direct sensation of the effects of radiation contributes to a subjective overestimation of the sense of danger. The known Russian physicist and historian Sergei Pereslegin, in his book “Myths of Chernobyl,” writes that the invisibility of radiation as a threat gives rise to an unconscious fear in some people of everything related to radiation, including nuclear power plants. When such a mechanism is launched, the arguments of the mind become powerless. Such a person begins to broadcast his fear to others, giving rise to collective hysteria.

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In particular, among the liquidators, there is what is called “invalidation” in official documents. There is a state of disability due to diseases of the nervous system, circulatory system, and mental disorders. No dose dependence of liquidators’ disability has been identified; it is assumed that the primary role here is played not by radiation but by social factors. The mortality of the liquidators from all causes, including cancer, does not exceed the same indicator for the male population of the country. Studies of the consequences of the Chernobyl disaster continue. Apparently, the most clearly so-called official point of view on the impact of the Chernobyl disaster on health can be expressed in the words of the famous Russian radiologist L.M. Rozhdestvensky: “… no significant adverse health effects of radiation in the region of low doses have been identified. The identified radiogenic consequences are associated with exceeding the permissible radiation doses.”

7.6.6 Other Points of View In addition to the above description of the impact of the Chernobyl disaster on health, two other points of view can be pointed out, which can be called extreme. The position of the famous American biologist, the founder of radiation hormesis Thomas Lucky, can be identified by the title of his two articles: “Improved health from Chernobyl,” 2006, and “Radiation prevents much cancer,” 2007. Lucky’s ideas are reflected in more detail in Sect. 8.4. Still, here for now, we note that according to Lucky, people who received low doses of radiation from the emissions from the Chernobyl accident are lucky. They got absolutely free of charge the very additional radiation that is necessary for a healthy and fulfilling life. A significant amount of materials represents the other extreme position. In 2006, English radiobiologists Ian Farley and David Sumner, on behalf of the European Green Movement, prepared an independent report, known by the Latin abbreviation TORCH (The Other Report on Chernobyl), containing criticism of “official data.” In 2011, the International Physicians for the Prevention of War (IPPNW) and the German Nuclear Radiation Protection Society (Gesellschaft für Strahlenschutz—GFS) published a report entitled “Chernobyl’s impact on health. 25 years after catastrophe,” which claims that the International Atomic Energy Agency and the World Health Organization underestimate the real

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data on the expected mortality from cancer compared to those contained in the original scientific articles. The Russian scientist, now deceased Corresponding Member of the Russian Academy of Sciences Alexei Vladimirovich Yablokov, honorary chairman of the Moscow Society for the Protection of Animals, and founder of the Russian branch of Greenpeace, continuously criticized nuclear energy and nuclear technology. In a concentrated form, the position of Yablokov and the scientists supporting him is reflected in the book “Chernobyl: the consequences of the Catastrophe for Man and Nature.” First published in 2007, it has been continuously revised and expanded. The author quotes this book from the sixth edition, published in 2016. Yablokov’s attitude to nuclear technology is evident from the title of the series of books written and published by him “Atomic Mythology”: “The Myth of the Safety of Low Doses of Radiation,” “The Myth of the environmental cleanliness of nuclear energy,” etc. Discarding the emotional approach to assessing the situation, which is present in many critical materials, one can single out scientifically substantiated claims to the “official” position: • Lack of reliable dose measurements; in many cases it was determined by calculation. • It is impossible to consider the exposure in the first days, in particular, it is known that in the first few days, the available dosimeters went off-scale. • It is difficult to consider the territorial patchiness of radioactive contamination and the effect of various radionuclides. • If doses from external exposure can, in principle, be measured, then the reliability of the determination of internal exposure doses raises serious doubts. The main fears expressed in alternative versions of the assessment of the situation do not concern the current situation but the prospects. Estimates based on a linear no-threshold model predict a very large number of illnesses and deaths. So, according to estimates by Canadian epidemiologist Rosalia Bertel, almost 2 million people will die from the consequences of the Chernobyl accident worldwide (the maximum estimate in the independent TORCH report is 60,000 deaths). Indeed, if billions of people live in contaminated territories, and the probability of radiation damage is linearly related to the dose, then no matter how small this probability is, the number of people affected is huge.

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7.6.7 Public Opinion The attitude to radiation that existed in society before Chernobyl can be called sluggish radiophobia. These sentiments are discussed in more detail in Chap. 4. And suddenly, Chernobyl broke out. As was customary in the Soviet Union, the authorities began to obfuscate in every possible way, and rumors became the main source of information about the accident and its scale. The country’s population has become accustomed to not trusting the authorities; it tended to trust the most pessimistic forecasts more than objective data. The “Zone” appeared in the Zone “stalkers.” Photographs of giant mushrooms, two-­ headed calves, and five-legged dogs were published in print and on television. Alarming reports in the media escalated the situation and contributed to increased psychological pressure. The negative image of Chernobyl turned out to be much more destructive than the explosion itself and radioactive contamination, not only for the infected regions but also for humanity as a whole. It became evident that Chernobyl stress is primarily informational in nature: There was a major accident in Chernobyl; the media made it a disaster.

Information from the article “Accident at the Chernobyl Nuclear Power Plant” in the public Wikipedia reports that Greenpeace and the International Organization “Doctors Against Nuclear War” claim that tens of thousands of people died as a result of the accident among the liquidators alone, 10 thousand cases of deformities in newborns were recorded in Europe, 10 thousand cases of thyroid cancer and another 50 thousand are expected. Ibid: According to Vyacheslav Grishin, a representative of the Chernobyl Union (an organization that unites liquidators from all over the CIS and the Baltic states), “25 thousand liquidators from Russia are now dead, and 70 thousand are disabled, the situation is approximately the same in Ukraine, and 10,000 liquidators from Belarus are now dead and 25,000 have a disability,” which is a total of 60,000 dead (10% of 600,000 liquidators) and 165,000 disabled. The media are exaggerating the possible dangers associated with real military operations, i.e., war, with the falls on nuclear power plants of aircrafts and missiles. Nightmare lovers point out that nuclear reactors are a tasty object of nuclear terrorism. Chernobyl sharply increased the fears of the population about the possible dangerous consequences of the action of radiation. Radiophobia has gripped the broad masses of the population, both in the affected areas and in Europe. One indicator of the spread of radiophobia is the high number of abortions in

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several European countries. Beginning in May 1986, many pregnant women in Europe feared that Chernobyl’s emissions would deform their unborn children. The number of documented abortions in Denmark, Greece, Italy, and other Western European countries is in the thousands. Still, according to rough estimates by the IAEA, Chernobyl caused about 100–200 thousand additional abortions, prompted by fear of congenital deformities. In our opinion, this number is too high. It is clear that people have become a victim not of radiation as such but of the media. Advocates and supporters of nuclear power, using much of the environmental and health research, show that, in principle, the negative effects have been minimized and a relatively favorable picture is currently emerging. Particularly zealous of them pay attention to the competent decisions of the leadership—this is an erroneous opinion, the heroic actions of the liquidators—this is true, and the timely evacuation of the population from the most affected areas—this is only partially true. Opponents of nuclear energy, using the materials of some studies, and mainly a linear non-threshold model, are trying to prove that the accident released much more radioactive nuclides than indicated in many official documents, the emissions are distributed over a much larger area, the doses are also noticeably larger and, consequently, there are many more sick and dead people. And the frightening numbers of upcoming cancers across Europe are based on a linear extrapolation of data for large doses. Many media members have made journalistic and political careers by inflating radiation dangers. Undoubtedly, representatives of the administration of the affected regions were also supporters of aggravating the situation since the severity of the situation (albeit unrealistic) determined the amount of funding for the regions. But whatever arguments are offered by the supporters of the opposing concepts, this does not affect the author’s position in any way, at least in this book. The author of this book does not defend nuclear energy, although he has no objections to it and even more. The author agrees that the explosion of the Chernobyl reactor is indeed a terrible accident. The author often repeats in this book that large doses are hazardous. And if an analysis free from bias and departmental interests shows that the emissions were more significant than they write in the “official” documents and the doses are greater and therefore more sick and dead, then what to do, especially if the measurements are made reliable and handled correctly. The author’s main position, which he defends in this book, is that in most studies, contrary to models, a threshold of dangerous long-term effects is found somewhere at the level of 50–100 mSv. And all those who are lucky

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enough to be beyond this threshold, i.e., to grab fewer doses, and this is still a large part of the population not only of Europe but also of the contaminated regions, remained healthy, and there were not and will not be millions of victims.

7.7 Fukushima: Liquidators and Population The most recent (last as of spring 2023) radiation accident of the highest, seventh degree of danger began at 14:46 local time on Friday, March 11, 2011. An earthquake of magnitude 9.0 with an epicenter in the Pacific Ocean 130 km from the east coast of Honshu Island caused a huge tsunami wave that hit nuclear power plants located on the coast 300 km north of Tokyo. Almost an hour after the shock, a 15-m wave flooded almost the entire area of the Fukushima Daiichi nuclear power plant. All reactors automatically shut down at the moment of impact. The subsequent inspection did not reveal any significant damage to the reactor structures caused by the earthquake. The power supply to the reactor systems from the network was disrupted due to damage at the time of the shock, but the backup diesel generators located in the basements of the turbine halls turned on. These generators provided slow cooling for all shutdown reactors. The actual disaster began about an hour after the earthquake when the backup generators of the three reactors of the Fukushima Daiichi nuclear power plant were flooded with water from tsunami waves. As a result, the power supply systems of the reactors were completely de-energized. Due to the shutdown of the generators responsible for the operation of the cooling systems, the circulation of the coolant stopped in three reactors. The temperature of the core and the pressure in it began to rise, and after a few hours, the central part of the reactors began to melt. And at 7 am on Saturday, a significant part of the core fell into the water at the bottom of the reactor vessel. Oxidation of zirconium fuel cells at high temperatures and in the presence of water vapor led to the release of hydrogen, and at 15:36 on Saturday, March 12, a hydrogen explosion occurred at reactor No. 1, tearing out the roof of the reactor hall. A fire broke out at reactor No. 4, apparently due to hydrogen that got here from the systems of reactor No. 3, contributing to the dispersion of radionuclides into the atmosphere. The illustrations of the state of four reactors of the Fukushima reactor complex before and after the accident are shown in Fig. 7.7. The chain of events described above led to a massive release of radionuclides. Initially, from March 12 to March 18, 2011, radionuclides entered

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After the accident

Fig. 7.7  The Fukushima nuclear power plant. Four reactors (1–4) before and after the accident. On the right figure “5” are the multiple trenches, which are the probable source of contaminated water, partly underground. Figure from Fukushima Daiichi Nuclear Power Plant, Wikipedia—https://en.wikipedia.org/wiki/Fukushima_Daiichi_ Nuclear_Power_Plant#. CC BY 3.0. (a) Source: Fukushima_I_nuclear_accidents_diagram. svg. Author: Sodacan. (b) Source: Own work; based on: Asahi Shimbun Newspaper, BBC News Website, and Diagram from Flickr. Author: Sodacan

mainly into the atmosphere. In the following weeks and months, both reactor cooling water and ocean water from the tsunami, contaminated with nuclides from the destroyed core, were discharged directly into the Pacific Ocean. A significant amount of radioactivity also fell on the soil. The main activity to eliminate the consequences of the accident was aimed at cooling the reactors. This was done by hundreds of Tepko employees, as well as contractors, firefighters, and the military. The radioactive nuclides released from the core created a significant radiation background. Near the damaged reactors, the dose rate was on the order of several hundred mSv/h. As of December 2011, about 23,000 emergency workers were involved in emergency operations. Unlike Chernobyl, the Fukushima accident did not result in radiation sickness. The effective doses received by most emergency workers were below the occupational dose limits set in Japan. Only 174 people exceeded the official criteria. Six emergency workers received doses greater than 250 mSv, with a maximum dose of 678 mSv, of which 590 mSv was due to internal contamination. On March 24, three emergency workers working at reactor No. 3 received relatively high radiation doses, and two had to go to the hospital because radioactive water seeped through protective clothing. However, they did not receive severe skin damage.

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In subsequent years, two cases of leukemia (October 2015 and August 2016) and one case of thyroid cancer (December 2016) were reported. And although these diseases arose after exposure, their relationship with exposure is not obvious. The situation in Fukushima, in general, and the radiation situation, in particular, are very different from what happened in Chernobyl. The radiation doses turned out to be significantly less than in Chernobyl after the accident, as well as in Hiroshima and Nagasaki after the bombing. Already knowing the experience of Chernobyl, the authorities quickly organized the evacuation of the population from the most contaminated areas. The fact that due to the iodine-rich food in Japan, the intake of radioactive iodine-131 into the thyroid gland turned out to be noticeably less than in Chernobyl also helped reduce the consequences of radioactive contamination. According to the data at the beginning of 2013, approximately 156 thousand people were evacuated from the contaminated territories. It should be taken into account that if the doses received by emergency workers could be determined from the readings of individual dosimeters, then to estimate the doses received by the population, mainly calculation methods were used. The public’s estimation of the doses received was based on the available information on the density of cesium-137 deposition in different areas, expressed as a function of time and the assumed zone and trajectory of the population. In some cases, individual radiation monitoring was used. A comparison of the calculated and instrumental methods for determining doses showed that the actual doses were generally lower than those obtained by calculation; the simulated doses were, as a rule, overestimated several times. The average effective dose of external exposure received by the adult population in the first year after the accident was approximately 0.8  mSv in Fukushima Prefecture. Doses of internal thyroid exposure due to iodine-131 by the adult population in the first year after the accident were about 10 mSv. The doses of internal radiation received by children were about three times higher. Doses in the rest of Japan, and even more so in the rest of the world, were noticeably lower. So, no case of deterministic effects of radiation injury has been identified among the population of the areas affected by radiation, and only remote stochastic consequences, mainly cancer, can be expected. Indeed, by 2021, out of approximately 300,000 children who have undergone thyroid ultrasounds, 116 are suspected of having cancer. It has been more than ten years since the accident, so if the radiation doses were sufficient to induce other types of cancer, they should have appeared by

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now. So far, there are no reports of this. Predictions that were made based on a linear non-threshold model are not implemented. The main problem faced by the population of Japan, just like in Chernobyl, is psychological. The main effect of the Fukushima accident is stress, depression, and fear.

7.8 Nuclear Industry Workers All activities in the nuclear industry are associated with radiation and, therefore, with a possible radiation hazard. Therefore, workers’ health in the nuclear industry has been and is being constantly and carefully monitored. So, the author, even when he was a student in laboratory work using radiation sources, received a personal dosimeter, signed a journal when receiving and handing over sources, and used tweezers or manipulators when moving the sources. And when working with sources, for the rest of my life, I had to pass exams on radiation safety regularly, do it myself, and then demand that employees comply with the relevant rules. I do not claim that we were impeccable in relation to these rules. We were fools and often showed carelessness. However, the doses we dealt with always fell into the category of small and unpleasant consequences from ionizing radiation; none of our fellow students and colleagues were recorded. Many detailed epidemiological studies have been published covering large populations of workers. Employees of all significant foreign nuclear enterprises were subjected to the survey. Cohorts numbered tens and hundreds of thousands of people. For example, the Japanese cohort of nuclear workers included 200,583 people. No statistically significant association between radiation exposure and mortality from all forms of cancer, including leukemia, was found among workers receiving low doses (average cumulative dose less than 50 mSv). Extensive research was carried out when the opportunity arose for this on the Russian Production Association Mayak contingent. The general result of all studies can be summarized as follows—doses above a certain limit are dangerous, they induce cancers, and small doses are safe or even beneficial. Some difference between different studies lies in the border between these areas. In summary, we can say that the average value of the limit, below which the long-term effects cannot be statistically significantly recorded even over a long observation period, is approximately 100 mSv. The usefulness of low doses is discussed in Chap. 8.

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7.9 Population and Personnel in the Nuclear Weapons Testing Areas 7.9.1 Nuclear Test Sites in the World The damaging effects of nuclear explosions are described in detail in Sect. 4.5.1. Obviously, neither the test personnel nor the population living in the test area are exposed to radiation directly from the explosion (except for those soldiers who participated in several military exercises using nuclear weapons). The danger is radioactive fallout. There are global fallouts, which almost evenly cover the globe’s territory and local fallouts. The global fallout from all the atmospheric testing of atomic weapons that have been so far due to the distribution over vast areas creates negligible doses. However, local fallout should be given special attention. The population in areas of local fallout is exposed to both external and internal radiation. External irradiation is created by well-penetrating gamma quanta from particles that have fallen to the ground, covering any surface, including plant foliage. The walls of buildings are shielded from radiation, so the actual doses depend on the mode of behavior of a certain individual and on how much time he spends outside buildings. Internal exposure is created by radioactive fallout that enters a person when eating, drinking, breathing, or directly through the skin. A significant part of the radioactive nuclides enters the body when consuming products grown in the contaminated area, meat, and dairy products from livestock grazing in the fields where radioactive fallout fell. Many test sites are located in sparsely populated areas, for example, the Russian test site on the Novaya Zemlya archipelago in the Arctic Ocean, the French test site in Sahara desert, French, British, and American test sites on the islands in the Pacific Ocean. A map of the test sites is shown in Fig. 7.8. Local fallout from these polygons did not create serious troubles. In addition, far from all polygons, there is information in the scientific literature about the fallout activity and the impact of fallout on the health of the surrounding population. In this section, we will describe the situation regarding only the three most active test sites: this is the Semipalatinsk test site, now in the Republic of Kazakhstan, where the USSR carried out tests, and two American test sites, one on its territory in the state of Nevada, the other on the Marshall Islands in the Pacific Ocean.

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Fig. 7.8  The location of the nuclear test sites. Only test sites where atmospheric tests were provided are shown. The map from Free-­world-­map.com, Printable blank world maps—http://www.free-­world-­maps.com/printable-­blank-­world-­maps. Labels and icons added by the author

7.9.2 Population of Kazakhstan: Semipalatinsk Test Site On the territory of Kazakhstan, 130 km northwest of Semipalatinsk (now the city of Semey) in the East Kazakhstan region, there was a Soviet test site. Its position is shown on the map of Kazakhstan in Fig. 7.9. The test site was located in the deserted Kazakh steppe; there were no settlements or any economic objects within a radius of up to a hundred kilometers. It is reported that during the organization of the test site in 1946, only a few families were resettled from the village of Moldar. The first nuclear weapon test in the Soviet Union, the RDS-1 implosion-­ type plutonium bomb, was carried out at this test site on August 29, 1949. The power of the bomb was 22 kt. After 4 years, on August 12, 1953, the RDS-6 s thermonuclear charge with a capacity of 400 kilotons was tested at the same test site. The explosion was low; the charge was placed on the tower at a height of 30 m above the ground. It has already been said that such explosions create strong radioactive contamination of the territory. Traces of this contamination are still preserved in some places. The first Soviet real thermonuclear bomb RDS-37 was dropped from an aircraft on November 22, 1955, and exploded at an altitude of about 2 km. From 1949 to 1989, at least 468 nuclear tests were carried out at the test site, including 125 atmospheric tests: 26 ground, 91 air, and 8 high-altitude. In addition, 343 underground nuclear charges exploded here (215 in tunnels and 128 in wells).

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Fig. 7.9  Map of the Republic of Kazakhstan. The Semipalatinsk Test Site is on the northeast side. The town Semey (former Semipalatinsk), the former capital Almaty, and the former Soviet cosmodrome Baikonur are shown. The capital of Kazakhstan is Astana, in 2019–2022, it was named Nursultan. Figure from Freeworldmaps.net, Asia, Kazakhstan—https://www.freeworldmaps.net/asia/kazakhstan/map.html. The property of Daniel Feher

It is believed that the products of most atmospheric explosions remained on the territory of the test site. Still, radioactive clouds from 55 atmospheric explosions and the gas fraction of 169 underground tests went beyond their limits. It was these 224 explosions that caused radiation contamination of the entire eastern part of the territory of Kazakhstan. By the decision of the leadership of the Republic of Kazakhstan on August 29, 1991, the Kazakh government closed the Semipalatinsk test site. A year later, the National Nuclear Center was created on its basis. The Semipalatinsk test site covers an area of 18,500 km2. It is almost a circle with a diameter of more than one hundred and fifty kilometers. It is clear that it is impossible to surround such an enterprise with a fence. However, certain sections of the test site, such as the so-called “Experimental Field” with an area of 300 km2, were fenced and carefully guarded. At the site, “Experimental Field” atmospheric explosions were carried out. In general, the territory of the test site is quite flat, but in the south, there is the Degelen mountain range. In this mountain range, tunnels were laid for underground explosions. Tunnels allow the delivery of explosive devices and measuring equipment horizontally, which is much more convenient than placing equipment in wells.

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On the left bank of the Shagan River, another Balapan test site was located in the southeastern part of the test site. The area of this site is 100 km2. It was used for underground testing in wells. On the site “Balapan,” there is the so-­ called Atomic Lake, which was formed due to the underground explosion “Shagan” to create a reservoir at the confluence of the Shagan and Ashchysu rivers. The slopes of the lake, thrown out as a result of the explosion, still retain significant radioactivity. According to the legend, most likely reliable, the first person to swim in the waters of the Atomic Lake was the then Minister of Medium Machine Building of the USSR, who supervised the Soviet nuclear industry, including the production of nuclear warheads, Slavsky Efim Pavlovich. Slavsky died in 1991 at 93, 26 years after this bathing. Until now, hundreds of fishermen and those who want to swim go to the shores of Atomic Lake. Here, shepherds bring cattle to drink. Only in 2009, Kazakhstan declared the territory of the test site an exclusion zone. After the closure, since 1991, scrap collectors have been operating at or near the site, removing the rails that used to deliver nuclear warheads deep underground, thousands of kilometers of power cables with copper conductors, and other metal equipment, which remained in large quantities at the abandoned site. The security was removed, and unknown people removed the existing fences, cut off, dug them up, and taken away in an unknown direction. Moreover, equipment used to create nuclear weapons remained at the test site. After the collapse of the Soviet Union and the departure of Russian scientists from Semipalatinsk in the tunnels where the tests were carried out, not only equipment but also about 200 kg of plutonium were left without any protection in containers on the territory of the test site. Mount Degelen, where there were the most tunnels for conducting underground nuclear tests and a particularly large amount of undeclared plutonium, was called “Plutonium Mountain.” From 1996 to 2012, Kazakhstan, Russia, and the United States conducted a secret operation at the test site to search for and collect these same 200 kgs of plutonium, as well as equipment used to create and test nuclear weapons. $150 million was spent on this work, part of the work was funded by the Nunn-Lugar program (Cooperative Threat Reduction Program), and part— directly by Los Alamos National Laboratory, USA. The story of the work with the legacy of Soviet nuclear testing was described in detail in the Report of the Belfer Center for Science and International Affairs titled “Plutonium Mountain: Inside the 17-year mission to secure a

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dangerous legacy of Soviet nuclear testing.” The report’s authors are Eben Harrell of the Belfer Center and well-known journalist, Pulitzer Prize-winning author David E. Hoffman. Now the local population uses a significant part of the test site land for livestock grazing. On the territory of the test site, there are peasant farms, places of cattle grazing, and agricultural production. The Semipalatinsk nuclear test site is the only nuclear test site in the world where the population lives and uses it for agricultural purposes. According to the Institute of Radiation Safety and Ecology of Kazakhstan during the tests, about 1.5 million people lived near the test site. Separate sections of the test site still retain significant concentrations of radioactive substances. As part of rehabilitating the former Semipalatinsk nuclear test site, the Kazakh authorities intend in 2024 to export radioactive soil for long-term storage to a special facility in the Pavlodar region. It is assumed that about 100 thousand cubic meters of radioactive soil will need to be removed from the area of the test site. It will be placed in a specially built storage facility for radioactive waste. When analyzing the state of health of the population in the area of the Semipalatinsk test site, one has to consider that the environmental situation in the northeast of Kazakhstan is generally unfavorable. Currently, there are eight uranium mining provinces in Kazakhstan, where uranium ore is mined in an outdated open pit. A significant part of energy in Kazakhstan is obtained from coal-fired power plants. In particular, 10–20 kilometers from the Balapan test site, the Karazhyra coal mine (the old name is Yubileiny) is being developed. A survey of the health status of the population of the East Kazakhstan region by specialists from the National Nuclear Center of the Republic of Kazakhstan carried out in the early 2000s showed that there are episodic increases in cancer mortality for population groups of 60  years and older (45  years and older at the time of exposure). However, no dependence of mortality on the dose was found in the range of accumulated doses of ~300–900 mSv, which casts doubt on the relationship of mortality with radiation. For younger residents of the exposed regions, no difference in mortality from the control regions was found, where no tests were conducted, and no fallout was recorded. It plays a role that the elderly were irradiated during atmospheric explosions, and the young only from accidental radioactive releases from underground tests.

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7.9.3 United States, Nevada Test Site To test nuclear weapons, the United States created a test site on its territory in the state of Nevada (NTS—Nevada Test Site, formerly Nevada Proving Ground) 105  km northwest of Las Vegas, not far from the border with California. Before that, after military use in 1945, the Americans conducted tests on the islands in the Pacific Ocean, but transporting equipment and personnel was difficult and expensive, so they decided to blow it up in their desert state of Nevada. In the period from 1951 to 1992, a total of 928 explosions were carried out at this test site; 98 of them were atmospheric, including ten high-altitude ones. During atmospheric explosions in the 1960s, the typical mushroom clouds from the explosions were visible for 100 miles in any direction, including Las Vegas, where people came as tourists to look at them. Some explosions were especially “dirty.” Three explosions: “Harry” on May 19, 1953, “Bee” on March 22, 1955, and “Smoky” on August 31, 1957, are responsible for half of the pollution carried by all atmospheric explosions to the United States. Explosions in the air created a large amount of radioactive materials carried in the direction of the wind and fell to the ground at some distance from the explosion site. The explosions were carried out at a time when the winds in this part of the United States blow mainly in an easterly direction so that the products of the explosion did not capture the cities of Las Vegas (140 km) and Los Angeles (420 km). On the path of the wind in the zone of maximum fallout, approximately 200 km from the landfill were towns in the south of Utah and in the north of Arizona. Not only atmospheric explosions created radioactive contamination of the area. In 14 underground explosions, there was a significant release of radioactive materials into the atmosphere. The most famous is the Baneberry underground explosion with a power of 10 kt, produced on 18.12.1970 at a depth of 278 m after the end of air tests. Contrary to calculations, the explosion tore apart geological rocks, and radioactive gases and dust escaped and then fell out, hitting, in particular, the test site workers. To refer to people exposed to the products of a nuclear explosion due to the transfer of these products by the wind in the United States, a special term “downwinders” has appeared. In 2011, the US Senate established National Downwinder Day on January 27, the day of the first explosion at the Nevada test site in 1951. And in 1990, the US Congress passed the Radiation Exposure Compensation Act, in which people exposed to radiation during nuclear weapons tests could receive

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compensation for their damaged health. The federal government paid almost $800 million in compensation, which about 16,000 people received. Only affected residents of the rural counties of Nevada, Utah, and Arizona fell under the Act. A survey of the health status of downwinders showed, on the one hand, an increase in the frequency of cancers in the population that received significant doses, but at the same time, a paradoxical fact—the lowest average incidence of cancers in the population of the states of Nevada, Utah, and Arizona compared to other states that were much less affected by radioactive fallout. More on this in Sect. 7.11. A short sad story with filmmakers is also related to testing nuclear weapons in Nevada. In 1956, the filming of “The Conqueror” took place in the contaminated area of Southern Utah near St. George. The film crew consisted of 220 people. Of these, 91 people developed cancer, and 46 died before 1980, including the lead actor, the famous Hollywood actor John Wayne, who played in many, mainly westerns of the 1930s and 1940s. Doctors believed that Wayne’s lung cancer in 1964, and the stomach cancer that brought him to the grave in 1979, was caused by radiation. However, Wayne attributed his illness to the habit of smoking up to 6 packs of cigarettes a day.

7.9.4 Pacific Islanders After the first test of a nuclear charge in the Alamogordo area in New Mexico, it became clear that the explosions created serious radioactive contamination, so the United States continued testing in the Marshall Islands in the Pacific Ocean. A total of 66 tests were carried out on the islands, from the explosion in Operation Crossroads on June 6, 1946, to the last explosion in Operation Hardtack on August 18, 1958. The total energy released from all explosions exceeded 100 Mt. The first explosions were made in the lagoon of Bikini Atoll. Before the explosion, 167 Micronesians who inhabited Bikini were relocated to Rongerik Island, and six months later, even further, 800  km southeast of Bikini, to Kili Island. See the Marshall Islands map in Fig. 4.10, and the map of Bikini Atoll in Fig. 4.11. In 1952, the United States began testing thermonuclear charges, among which the best known is the 15 Mt Bravo explosion from the Ivy series on Bikini Atoll on March 1, 1954, which we described in Sect. 4.7. It is known that the explosion turned out to be much more powerful than expected, and the wind unexpectedly turned east, toward other islands. As a

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result, radioactive fallout fell on the inhabitants of Ailinginae Atoll (18 people), Rongelap Island (64 people), and Utrik Atoll (167 inhabitants). On Rongerik Atoll, 28 American meteorologists were exposed to radioactive fallout. Although the inhabitants of the islands were resettled for the duration of the tests, they were exposed to radiation for various reasons. Stephen Simon and his colleagues at the US National Cancer Institute conducted the most extensive surveys of deposition, accumulated doses, and cancer risk for almost the entire population of the Marshall Islands, both for those who were exposed during the tests and those who were born later and was only affected by long-lived nuclides deposited and preserved on the islands. According to Simon and colleagues, the fallout from 20 out of 66 explosions created conditions for excess exposure, but the Bravo explosion dominated. The doses received from radioactive fallout at Bikini Atoll are the most significant doses received by the population near all nuclear weapons testing sites. External exposure doses for the adult population of the northern islands and atolls reached 1 Gy. Doses of internal irradiation of the thyroid gland were even higher, adults up to 7–8 Gy, children—even 3 times more. The bulk of the doses were received during and shortly after the explosion. Subsequent irradiation from the radioactive fallout created much lower doses. According to studies published in 2010, approximately 170 radiation-­ related cancers were expected among the approximately 25,000 inhabitants of the archipelago in the early 1970s. More than a hundred cancers by 2010 have already been realized. The authors of the investigation propose to compare 170 radiation-induced cancers with more than 10 thousand cancers that spontaneously form in the same cohort, regardless of exposure. Currently (2020—Wikipedia), the population of the Marshall Islands is about 60 thousand people. The Marshall Islands are largely made up of coral, or as biologists say, from the skeleton of a colony of coral polyps. Live corals grow in the lagoons. Thermonuclear explosions have caused extreme destruction in coral communities. The white powder that fell after the Bravo explosion on the islands and on the ship Fukuryu-Maru, which the fishermen called “ashes of the burning sky,” was corals ground into dust with radioactive nuclides adhering to dust particles.

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The Bravo explosion formed a 73 m deep crater. In addition, underwater explosions were carried out on the islands, or explosions of charges placed on barges. All of them caused especially serious damage to all biocenoses in the lagoon. Fifty years after the Bravo explosion, a group of experts from several Australian scientific organizations examined the condition of the corals in Bikini Atoll. It determined that Bikini Atoll’s corals proved quite resilient to large-scale human impacts. The biodiversity of the coral community has slightly decreased, but new species have emerged. This is a promising result. If living corals had withstood the nightmare happening in the lagoon of Bikini Atoll, then everything would not have been so bad. Nature has a margin of safety. Public health surveys in Kazakhstan, Nevada, Utah, Arizona, and the Pacific Islands started with significant delays. The survey results confirm the data obtained in other cohorts: large and medium doses pose a certain dose-­ dependent danger, and small doses are safe.

7.9.5 Personnel The situation with the personnel serving the tests differs sharply from that with the population. First, the staff is healthy; there are no sick, elderly, children, and pregnant women, i.e., people for whom radiation exposure is especially dangerous. Second, special measures were taken to protect personnel. In addition, the test site workers and military observers often had dosimeters, so the doses they received could be determined much more reliably. In the UK’s cohort of 22,347 participants in atmospheric nuclear weapons testing, no significant effects of increased mortality or risk of any form of cancer or other fatal disease were observed. This was shown by a group led by Sarah Darby from Oxford University. A team of Australian scientists studied a cohort of 10,983 Australians who participated in the British trials in Australia. No association between exposure and all possible cancer cases or deaths has been found. Here, we also note the fate of Japanese fishermen who suffered from radioactive fallout during tests of a thermonuclear device on Bikini Atoll in 1954 (Sect. 4.7). In an article by Japanese scientists T. Kumatori and colleagues, published in 1980, it is reported that over 25 years of monitoring the health of fishermen from many fishing schooners that fell under the fallout of a thermonuclear explosion, not a single case of the disease was detected cancer (except for the fishermen of Fukuryu-Maru).

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7.10 Crews and Passengers of Long-Distance Flights and Astronauts The crews and passengers of long-haul flights and astronauts fly away from the effects of terrestrial radiation, but at altitude, they are waited for by increased doses of cosmic radiation.

7.10.1 Cosmic Rays One of the essential sources of ionizing radiation is cosmic rays, penetrating everything on Earth throughout its existence. In the formation of the radiation environment at the flight altitudes of commercial airliners and spacecraft, it is necessary to take into account four types of cosmic radiation: “galactic,” let’s call it primary, “solar,” “captured in the radiation belts,” and “secondary,” formed by the primary in the atmosphere. Galactic radiation comes to the solar system from interstellar space almost uniformly in direction and more or less uniformly in time. Galactic cosmic rays tend to be highly energetic, highly penetrating particles, mainly protons with energies of the order of GeV (billion electron volts), with a small addition of alpha particles and heavier nuclei. The modest depths of shielding do not stop them on a typical spacecraft. Fluxes of galactic particles vary according to solar cycles. The most significant fluxes are observed during the years of minimum solar activity because the solar wind, whose intensity grows with the growth of solar activity, prevents the penetration of galactic particles into the solar system. The average flux of galactic particles at the atmosphere’s boundary is roughly one particle per 1 cm2 per 1 s. Cosmic particles of solar origin are protons and electrons of much lower energy. It means that shielding is much more effective against solar than galactic rays. Solar cosmic radiation experiences a periodic change in intensity associated with changes in solar activity. The most famous is the 11-year cycle. In addition, solar radiation experiences random bursts of intensity called “solar flares.” Processes in the solar corona determine flares and are unpredictable with the current understanding of the dynamics of the Sun. The Earth’s magnetic field deflects the movement of charged particles toward the poles. Charged particles with less than certain critical energy are captured by the Earth’s magnetic field and form radiation belts, zones with an increased concentration of particles surrounding the Earth (Fig. 7.10). The difference in the type and energy of the particles led to the formation of two belts—internal and external. The inner belt consists mainly of protons, while

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South Atlantic Anomaly

Fig. 7.10  Schematic representation of radiation belts

Fig. 7.11  Formation of secondary cosmic radiation

the outer belt consists of electrons. Between the inner and outer belts, there is a gap, a vast area with significantly lower particle fluxes. In the equatorial plane, the inner radiation belt extends at altitudes from 600 to 6 thousand km (0.1–1 Earth radii), and the outer belt—from 20 to 60 thousand km (3–10 Earth radii). High-energy particles of primary cosmic radiation collide with atmospheric atoms, split nuclei, and give rise to unstable elementary particles (Fig. 7.11).

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40

Life zone

Radiation intensity

50

30 20 10 0 0

5

10

15

20

25

30

35

40

45

50

55

60

Height, km

Fig. 7.12  The dependence of the intensity of cosmic radiation on the height above sea level. At altitudes above 50 km, only the primary component of cosmic radiation comes from world space, and the radiation intensity does not depend on altitude. Below 50  km, the intensity first increases due to the formation of secondary particles and then decreases due to increasing atmospheric absorption

This is how secondary cosmic radiation is formed. Starting from the boundaries of the atmosphere to a height of about 20  km, the intensity of cosmic radiation increases due to the production of secondary particles, and then absorption processes begin to dominate, and the intensity decreases (Fig. 7.12).

7.10.2 Radiation Condition in Space In outer space, there is no secondary radiation that occurs in the Earth’s atmosphere. Radiation belts only affect astronauts on interplanetary flights to the Moon or Mars for the short time that their spacecraft traverses these belts, so the health effects of radiation from the belts are almost negligible. Thus, two components remain in outer space: galactic and solar radiation. The share of solar cosmic radiation penetrating near-Earth orbit is small due to the protective effect of the Earth’s magnetic field. Besides, the energy of solar cosmic particles is relatively low. So, a small part of solar particles that nevertheless penetrate near-Earth orbits is significantly weakened behind the real protection of the household compartment of the spacecraft. Therefore, when calculating the generalized dose and radiation risk, the contribution of the solar component for orbital flights is usually not taken into account. Real protection from galactic radiation is impossible.

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In addition to heavy charged particles of galactic origin (mainly protons), a certain contribution to the absorbed dose is made by secondary radiation, in particular neutrons, which occur in the structural elements of the spacecraft and in the body of astronauts. The contribution of neutrons to the total dose is about 10% of the dose of charged particles and grows with the thickness of the shield. The crewed spacecraft and space station routes pass at an altitude of 300–500 km below the internal radiation belt. For a short time, spaceships touch a section of the radiation belt on orbits passing through the region of the Brazilian magnetic anomaly. Therefore, some contribution to the total dose comes from particles trapped in the radiation belt. Solar flares could have a very sharp effect on the radiation situation in free space. Thus, calculations show that the solar flare of August 1972 created a dose on the Moon’s surface during the same time that the Apollo-16 astronauts spent on the Moon later, about 4 Sv. It is almost a lethal dose. Fortunately, the Apollo-16 lunar mission took place in April, and the next one, Apollo-17, in December of this year. At a distance from the Sun, at which the Earth’s orbit is located, dose loads from flares can reach ten Gy. True, the probability of strong flashes is relatively small. Since in outer space, the main effect on the body is produced by heavy charged particles (protons, alpha particles, and heavier nuclei), the numerical values of equivalent doses measured in sieverts significantly exceed the numerical values of absorbed doses measured in grays. The average coefficient relating equivalent and absorbed doses in outer space, i.e., the average radiation quality factor (in other words, Radiation Weighting Factor—see Appendix), is assumed to be approximately 5. This means that an absorbed dose of the order of 200 mGy leads to biological effects corresponding to an equivalent dose of the order of 1 Sv. The same remark applies to long-range aviation crews (and passengers). However, in this case, the quality factor is slightly lower. Now, we present the quantitative characteristics of the radiation situation in outer space. It should be noted that the dose rate in space is not constant. Even disregarding rare and irregular solar flares, the dose rate varies over an 11-year solar cycle. The dose rate in free space is approximately a factor of 2.5 higher at a solar minimum than at a solar maximum. Far from the planets at the level of the orbits of the Earth and Mars in the period of solar maximum, the dose rate can be about 400 mSv/year. During solar minimum, the dose rate can be twice as high.

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On the surface of Mars and the Moon, astronauts are exposed to radiation of the same intensity, but the surface of the planet and our satellite shield about half the intensity; their own radiation adds a small fraction. On Mars, the weak Martian atmosphere also plays some role, so the dose rate on the surface of Mars is approximately 100  mSv/year. On the lunar surface, the annual exposure caused by Galactic Cosmic Rays is roughly 380 mSv (solar minimum) and 110 mSv (solar maximum). The dose rate in low Earth orbits of space stations is ~100 mSv/year.

7.10.3 Radiation Environment for Flights of Airliners The radiation field in the aircraft cabin differs very little from the field in the free atmosphere. The peculiarity of the radiation effect on the body of cosmic radiation at flight altitude lies in the significant role of protons and neutrons, which differs significantly from the effect of alpha, beta, and gamma radiation well studied in many cohorts. The cosmic radiation spectrum at flight altitude consists of 55% neutrons, 20% electrons and positrons, and 15% protons. The remaining 10% are muons and gamma radiation. The particle energies are such that radiation with high and low LET are present in comparable proportions. The radiation intensity is approximately evenly distributed over the aircraft. Before the jet era, the dose rate in flight was ~0.2  μSv/h. Jet planes fly higher, and the dose rate has increased accordingly. At the flight altitudes of modern airliners, the average dose rate is in the range of 1.5–10 μSv/h. The smaller value corresponds to flights in the equatorial zone, and the largest for intercontinental flights Europe–United States, Europe–Far East, and United States–China, made through the polar regions. The state of solar activity affects the doses received during flights. The dependence on the route and date of the flight according to the official website of air carriers is illustrated by the graph in Fig. 7.13. It can be seen that in flights along the polar route (Frankfurt–New York), the doses per flight are higher and vary significantly depending on the date of the flight compared to the flight along the trans-­ equatorial route (Frankfurt–Johannesburg, South Africa). The dependence on flight altitude is evident without further explanation. The dose rate is currently assumed to be ~3 μSv/h for rough estimates. During solar flares, the radiation dose rate at commercial aircraft flight altitudes can reach 200 μSv/h for up to several hours. True, such outbreaks are rare and the probability of falling under their action is small. In addition,

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Frankfurt - New York (polar route)

Dose per filght, μSv

80 70 60 50 40

Frankfurt - Johannesburg (trans-equational route)

30 20

Jan 2015

Jan 2014

Jan 2013

Jan 2012

Jan 2011

Jan 2010

Jan 2009

Jan 2008

Jan 2007

Jan 2006

Jan 2005

0

Jan 2004

10

Fig. 7.13  Change in the dose received per flight depending on the route and date of the flight during 2004–2015. The upper graph is the flight Frankfurt–New York (polar route), and the lower graph is the flight Frankfurt–Johannesburg (trans-equatorial route), comparable in duration

“space weather” services monitor the processes on the Sun, and then the flight routes change or even flights are delayed. The number of hours in flight for crews varies greatly; it is generally accepted that it is 300–900 h/year, and the average time is about 500 h. For frequent flyers, the average flight time is estimated at 100 h. Members of the crew of airliners accumulate a particularly large dose—up to 5  mSv/year, on average about 1.6  mSv/year. Annual doses of passengers making four flights across the Atlantic per year reach ~0.2–0.4 mSv. Significantly, the increased doses of radiation in commercial flights affect a very significant number of people. Thus, in the United States, approximately 175 thousand people are employed in the flight part of air transport. About half of them are flight attendants, and many of them are women. In addition to ionizing radiation, flight personnel are exposed to the electromagnetic fields of onboard instruments, aviation fuel vapors and exhaust gases, and specific aerosol components of the aircraft cabin atmosphere. In addition, the health of flight personnel can be affected by sleep-wake disturbance associated with long flights and crossing many time zones. Radiation in flight affects both crew and passengers similarly, but as a rule, aviators fly more, although there are exceptions.

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Recently, biologist and writer Timothy J. Jorgensen spoke about a businessman, Tom Stuker, who has flown almost 30 million kilometers over the past 14 years. Jorgensen told about the funny details of such aviation activity: during the flights, Stucker ate 6500 airplane breakfasts, drank 5250 servings of alcoholic beverages, watched thousands of movies, and visited the aircraft toilet at least 10,000 times. But what is important, according to Jorgensen’s estimates, during the flights, he accumulated a radiation dose only from cosmic radiation of the order of 100 mSv. No health issues have been reported for Tom Stucker. We are not aware of epidemiological studies of the effects of radiation on passengers on long-distance flights. However, this is understandable. The total doses received by passengers do not pose a hazard. However, the impact of increased doses of radiation on the health and mortality of crew members is an understandable concern, and their health status has been the subject of a significant number of epidemiological studies. The main flight routes of supersonic aircraft that previously flew: Concorde and TU-144 passed at an altitude of ~20 km. It is assumed that future supersonic aircraft will fly even higher. It is clear that the dose rates in all these cases will be higher, but the flight duration is shorter, and the total dose per flight also turns out to be less than on subsonic aircraft. When the projected supersonic aircraft will fly is not very clear, but almost space, so-called suborbital flights have already begun. On July 11, 2021, billionaire Virgin Galactic founder Richard Branson’s Unity rocket plane went on a suborbital flight with a crew of five more, rising to a height of over 80 km. On July 20 of the same year, Blue Origin’s New Shepard spacecraft, with Amazon founder Jeff Bezos made a suborbital flight. There were three people on board this ship. Although the dose rates at the highest points of the flights of these ships were significant, the flights themselves were short-lived, and there was no need to worry about the doses received by the crews. It is obvious that these flights are just the beginning. The era of almost space, suborbital flights, both for tourism purposes and subsequently for flights from continent to continent, is beginning, and the problem of the effects of radiation on passengers and crew will have to be considered. An analysis of the morbidity and mortality of long-distance aircraft crew members showed that they are, in general, less than that of the general population. Therefore, we moved this issue to Chap. 8.

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7.11 Population Living in the Area of Nuclear Facilities Epidemiological studies of the impact of radiation in the area of nuclear facilities on the population’s health are not very informative and unreliable since, in this case, the doses are quite small and poorly defined. In most cases, the doses of possible exposures were determined by the distance from the nuclear facility where the population lived. The effects of these small doses are lost against the fluctuations of a much more significant background. Leukemia is the earliest and most easily detected indicator of radiation exposure, and childhood leukemia is the most clearly detected. Therefore, most research is devoted to analyzing the disease of children, young people, or even babies irradiated in the perinatal state. Despite the difficulties in obtaining reliable information, extensive epidemiological studies of relevant cohorts are being conducted because of the great importance of this information. The report of the Scientific Committee on the Biological Effects of Ionizing Radiation (BEIR) of the US Academy of Sciences reports on studies of the health status of populations living in the vicinity of nuclear facilities in the United States, Israel, Germany, Canada, the UK, France, Sweden, and Slovakia. In most studies, finding a connection between the identified diseases and radiation was impossible. Extensive epidemiological studies of childhood leukemia in areas of known accidents at nuclear power plants in the Sellafield region in England, near the Dounreay nuclear power development center near the town of Thurso in Scotland, or at the La Hague radioactive waste processing and disposal site in France show that doses from releases of radioactive substances are usually less than doses from natural background radiation. Despite intensive attempts, it is impossible to identify the relationship between diseases and releases. A special program attempted to determine the doses received by members of a cohort of 3000 people born in the vicinity of Hanford and exposed to iodine-131 from the plutonium production complex in the 1940s and still alive at the time of the studies in the 1980s. Some cohort members were estimated to receive a thyroid dose over 1 Sv, but the average dose was 174 mSv. This study found no additional risk of thyroid cancer associated with radiation.

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7.12 Population in Areas with a High Background 7.12.1 The Areas with a High Background Environmental radioactivity is believed to contribute about 0.35  mSv/year and cosmic radiation about 0.3 mSv/year to the average radiation background on Earth. However, there are places on Earth where the contribution of environmental radioactivity is evidently more significant than the indicated average value; in the other places, the contribution of cosmic radiation is much more significant. In fact, the natural radiation background on planet Earth varies within almost three orders of magnitude. In some places, radioactive elements accumulate in significant concentrations near the earth’s surface, and the dose rate of the natural background reaches almost 1 Sv/year. Placers of heavy sands with a high concentration of monazite, a mineral containing up to 10% thorium and up to 1% uranium, occupy large areas (tens and hundreds of square kilometers) on the coasts of India, Brazil, China, and smaller areas in other regions of the world. In Iran, a significant near-­ surface radium concentration forms the high background zone. In addition to the four regions listed above, a high and even greater background can be found in other places on Earth. Such areas exist in Norway, Switzerland, Australia, and others. In the South-East of France, near Montpellier, French researchers (A Léonard, M Delpoux) discovered places with a particularly high background, where rocks with a high concentration of uranium, thorium, and radium are located close to the surface. The dose rate in the Lodeve and Laurageais regions is ~0.9 Sv/year; in the Rivieral region, it is even higher, up to ~1.3 Sv/year. Russian researchers (V.I. Maslov and colleagues) discovered a zone with an extensive background in the northern taiga of Russia on the territory of the Komi Republic. The maximum value measured by them was 1.6 Sv/year. As a rule, people do not live in these spatially limited places, but animals live, including burrowing animals, birds, insects, trees, shrubs, and grasses grow. And not just live, but prosper and demonstrate hormesis, but more on that in the next chapter. Table 7.2 provides information on the dose rate in particular areas of high background radiation.

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Table 7.2  Dose rate in particular areas of high background radiation Dose rate, mSv/year Country

District

average

maximum

China India Iran Brasil

Yangjiang Karunagapally Ramsar Guarapari

5.3 3.8 10.2 13

16.4 76.5 260 175

Average world radiation background of external 1.3 exposure

Fig. 7.14  Yangjiang area in southern China. Figure from Freeworldmaps.net, Asia, China—https://www.freeworldmaps.net/asia/china/map.html. The property of Daniel Feher

7.12.2 China, District Yangjiang In southern China, on the coast of the South China Sea in Guangdong Province, there is Yangjiang County with areas of about 540 km2 with a high background radiation (Fig. 7.14). About 125 thousand people live in these areas, mostly peasants. Families with at least six generations of ancestors living in these areas comprise 90% of the population. Significantly, radioactivity is found not only in the soil but also in the building materials from which houses are built. The health status of a cohort of thousands of men and women aged 30 to 74 years was monitored during 1979–1998. Studies have shown that mortality from leukemia and other cancer types is unrelated to the accumulated radiation dose.

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7.12.3 India, District Karunagapally In the southwest of India, on the coast of the Indian Ocean, in the state of Kerala, there is the Karunagapally region with outcrops of monazite (Fig. 7.15). About 360 thousand people inhabit the high background zone; the migration of the population in this area is insignificant. The average annual external exposure dose is approximately 3.8  mSv/year. In some places, the external radiation dose can reach 70 mSv/year. Neither leukemia nor various types of cancer were associated with radiation doses.

7.12.4 Iran, District Ramsar In Iran, on the coast of the Caspian Sea, in the province of Mazandaran, there is the Ramsar region, some areas of which have a particularly high level of

Fig. 7.15  The Karunagapalli district in the state of Kerala in the South of India. Figure from Freeworldmaps.net, Asia, India, State Kerala—https://www.freeworldmaps.net/ asia/india/kerala/. The property of Daniel Feher

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radiation (Fig. 7.16). One of the districts in this province, Talesh Mahalleh is the most radioactive place in the world. The main reason for such a high level is the emergence of geothermal waters that dissolve radium in uranium-bearing rocks. Because of these waters, soils and products grown on these soils exhibit high radioactivity. Around Ramsar, at least nine hot springs are known with varying concentrations of radioactivity. Both the local population and visitors use these sources for recreational purposes. In addition, the local population uses materials enriched with radium to build their homes. The maximum annual dose received by some part of the population of Ramsar reaches 260 mSv/year. Given that the maximum annual dose for workers in the nuclear industry is 20 mSv/year, some residents of Ramsar receive a dose more than an order of magnitude higher than the permitted dose for nuclear workers. There was no increase in the incidence of cancers or leukemia among the population of the Ramsar district. There was also no change in the life expectancy of the inhabitants of Ramsar compared to the population of nearby areas with a normal level of background radiation. The cells of lymphocytes from the residents of Ramsar have a particularly high radioresistance. This property is noted in Sect. 8.11.

Fig. 7.16  The region of Ramsar in Iran is on the shores of the Caspian Sea with one of the highest background radiation levels in the world. Figure from Freeworldmaps.net, Asia, Iran—https://www.freeworldmaps.net/asia/iran/map.html. The property of Daniel Feher

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7.12.5 Brazil, District Guarapari In Brazil, along the coast of the Atlantic Ocean, there is a long strip of beaches where the sand has increased radioactivity. The radiation source is the sand of destroyed thorium-containing monazite rocks in significant quantities in the mountains stretching along the coast. The most famous are the beaches around the city of Guarapari in the state of Espirito Santo (Fig. 7.17). A high radiation background is observed in some “hot” places on the coast and the fishing village of Meaipe. Both in Guarapari and in Meaipe, the dose rate is up to 20 mSv/y, but in some places on the coast, it reaches 175 mSv/year. The population of Guarapari is about 127 thousand. (2020). It is a popular tourist destination due to its white sand beaches backed by commercial enterprises extending southward to Nova Guarapari and Meaípe. Epidemiological studies in Guarapari showed no excess of cancers caused by background radiation. In addition, there are other places in Brazil that are characterized by increased background radiation. They are the areas of Pocos de Caldas, Araxá, and Tapira in the state of Minas Gerais.

7.12.6 Life in High Mountain Areas Almost 140 million people on Earth live as high as over 2500 m above sea level. Especially many highland inhabitants there are in the Andes and in the

Fig. 7.17  District Guarapari in the state of Espirito Santo in Brazil. Figure from Freeworldmaps.net, South America. Brazil—https://www.freeworldmaps.net/southamerica/brazil/. The property of Daniel Feher

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Himalayas. Table  7.3 shows some of the highest mountainous towns, the most densely populated. The most permanent mountainous settlement of people is in the village La Rinconada in the Peruvian Andes at 5100 m above sea level. It is a known fact that even higher, at 5950 m at atmospheric pressure of 275 hPa some people could survive for two years. This is the absolute long stay record for a human being at the highest altitudes. The atmospheric pressure decreases exponentially with height, but an oxygen concentration of 20.9% stays constant up to the height of about 100 km. Thus, the absolute oxygen content also decreases exponentially. At 5000 m, the amount of oxygen is about half as low as at sea level. The decrease of oxygen in the air is the major problem of survival at high altitudes. With height increase, the dose rate also increases due to cosmic radiation. At sea level, it is ~0.03 mSv/year and then increases with height. The dependence of the intensity of cosmic radiation on the height above sea level is shown in Fig. 7.12. The average dose rate at the height of 4000 m is ~1.75 mSv/ year. Thus, the heights at which humans can live are not dangerous because of radiation, and the heights at which radiation becomes dangerous are inaccessible to life mainly because of lack of oxygen. In the highlands—in the city of Mexico (2240 m), in the city of Bogota, the capital of Columbia (2600 m), in the city of Quito (2850 m), the capital of Ecuador, the level of space radiation is 5 times higher than at sea level. It is even higher in the Tibetan town of Lhasa in China (4200 m). All these cities live, grow, and the population is relatively safe. Of course, there are problems Table 7.3  The highest mountainous towns, their population, and equivalent dose rate of cosmic radiation Dose rate Towns

Height, km

Population, thousand

μSv/h

mSv/year

La Rinconada, Peru Lhasa. Tibet, China El Alto, Bolivia Potosi, Bolivia Juliaca, Peru Oruro, Bolivia La Pas, Bolivia Sucre, Bolivia Quito, Ecuador Bogota, Columbia Sana’a, Yemen Mexico City, Mexico Sea level—New York

5.1 4.2 4.15 4.09 3.83 3.71 3.64 2.9 2.85 2.64 2.3 2.24 0

30 900 1700 250 276 210 1800 300 1600 7400 3900 8900 8500

0.32 0.21 0.20 0.20 0.18 0.17 0.16 0.13 0.13 0.12 0.11 0.11 0.03

2.8 1.8 1.75 1.75 1.6 1.5 1.4 1.14 1.14 1.05 0.96 0.96 0.26

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(for example, air quality in Mexico City), but it is evident that they are not associated with increased background radiation. The difference in incidence in different US cities was studied in detail. For example, the space background of the residents of Denver in the state of Colorado, USA (~ 1600 m over the sea level), is about 0,5 mSv/year and that is almost twice as high as for the background of residents of Boston, that is located at the ocean. The research of 1999 showed that the cancer possibility in Massachusetts was 16% higher than in Colorado, which could mean that in the indicated range of doses and irradiation conditions, radiation hormesis manifests itself. A similar result was obtained by comparing the population of the Rocky Mountains and coastal states more extensively. The results undoubtedly show that the radiation background in the highlands is higher, but the cancer frequency there is lower. The same results were obtained in Canada. However, the conscientious approach to the data analyses requires considering all factors that could influence the result. Thus, a significant part of the population of the state of Utah and some other mountain states are Mormons who do not smoke and do not drink either alcohol or coffee. Perhaps, this is why the frequency of cancer in Mormons is twice as low as in their neighbors, non-­ Mormons. In coastal states, besides, the pollution industry is concentrated. Given this, the authors of the research conclude that at least the radiation in the range of several mSv/year cannot be taken as significant for cancer induction as compared with the other factors.

7.13 Conclusion The first important conclusion that can be drawn from the analysis of the effect of radiation in all the cohorts described in this chapter is that the linear non-threshold model is not valid, there is a threshold in the effect of radiation, and doses below the threshold are safe. The second conclusion is that radiation is a rather weak carcinogen since the probability of cancer induction, even at doses at the survival limit, is small. Let’s illustrate this statement with several examples. The probability of cancer determined from data for high doses per dose unit is 5% per 1 Sv. This means that with a lethal dose of 5 Sv, the probability of cancer is only 25%. Many chemicals are much more powerful carcinogens than radiation. The introduction of strong carcinogens into the body leads to cancer with almost one hundred percent probability. For example, the Carcinogenic Potency

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Database (CPDB) contains TD50 values, i.e., doses of 50% mortality for substances studied in chronic experiments on rodents. The minimum value, i.e., the most carcinogenic to mice, is a dioxin derivative (2,3,7,8-Tetrachlorodibenzo-­p-dioxin). Its TD50 is equal to 1.56∙10−4  mg/ kg/day. For a mouse weighing 50 g, this corresponds to approximately 10 ng/ day. 10 nanograms is about a million times less than the weight of a poppy seed. As a result of the Chernobyl accident, 134 people were diagnosed with acute radiation sickness. Of these 134 people, 28 died within a few months, but of the remaining 106, 22 died over the next 19  years, and 26 died in 30 years, which is noticeably less than the death rate in the rest of Russia. Another example is that among the victims of the nuclear bombing of Japanese cities during 1958–2009, about 2500 people died from cancer caused by radiation, and more than 20 thousand from various causes unrelated to radiation. In Sect. 7.9.5, we have already indicated that in 25 years of monitoring the health of Japanese fishermen affected by thermonuclear tests in the Pacific Ocean, no case of cancer has been detected (except for the Fukuryu-Maru fishermen). Many examples and analogies are given in the literature to illustrate why a linear no-threshold model may not work and why low doses of radiation may be pretty harmless. Although it is known that analogy is not a method of proof, it shows the logical inconsistency of a simple linear relationship. So, for example, the well-known Polish radiobiologist Zbigniew Jaworowski points out that since a temperature of 200 °C can cause a third-degree burn, then a completely comfortable temperature of 20  °C could actually be considered dangerous, but not to the same extent. Z. Yaworowski so definitely and actively defended the ideas of the safety of low doses of radiation and radiation hormesis that he deserves to be specially noted in this book (Fig. 7.18). In a 2010 article, Yaworowski argued that if all the atomic bombs and nuclear warheads accumulated at the peak of the arms race, with a total number of approximately 50,000 pieces and a total capacity of 13,000 megatons, were detonated within a few days, then global fallout would create for the average person in 70 years of life, a total dose of about 55 mSv, i.e., less than 1 mSv/year on average. An example of the incompetence of linear extrapolation is given by Moscow physicists A.B. Koldobsky and V.P. Nasonov. If a car, having consumed 10 liters of gasoline, travels 100 km, then it can be stated with sufficient certainty that it will travel 50 km after spending 5 liters. The question is how much the

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Fig. 7.18  Zbigniew Jaworowski (1927–2011), Polish physician, radiobiologist, and public figure, in 1981–1982—Chairman of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR)

car will travel on 1 drop of gasoline. If we take the volume of a drop equal to 0.1 cm3 for evaluation, then, considering the linear dependence, the car must travel 1 m per 1 drop. However, elementary common sense suggests that the car will not even move on one drop introduced into an empty tank. The above example clearly shows that there is a threshold here. Another example is given by Ed Hiserodt, already cited in this book. A fall from a height of 100 m is fatal. However, linear extrapolation is not fair. A fall from a height of 10 cm is harmless. In conclusion, we give an example of the influence of the method of presenting experimental material on the solution of the question of the presence of a threshold from the report of a group of scientists at the University of Oslo, headed by Thormod Henriksen, published in 2016. The two graphs in Fig. 7.19 show the same sarcoma probability data for “radium girls” (see Sect. 4.4 and Fig. 7.1) as a function of dose. The graphs differ in the scale of the abscissa axis (X-axis). On the left—a linear scale, several points at low doses practically overlap. On the right is a logarithmic scale. In this case, it can be seen that in a wide dose range from 0.1 to 8 Gy, the probability of osteosarcoma does not increase with increasing dose and is practically zero. The given pair of graphs shows that, in this case, there is a threshold, but on a linear scale, it is lost (Fig. 7.19).

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Fig. 7.19  Dose dependence of the incidence of osteosarcoma in radium girls per person and year. The two graphs show the same data, but the dose axis in the left graph is on a linear scale, and the right graph shows the dose on a logarithmic scale. The straight line in the left graph follows the LNT hypothesis. Figure on the basis of T.E. Henriksen E. Sagstuen, E. Pettersen, E.O. Hole, N.J. Edin. Radon, lung cancer and the LNT model. Research and review BMF-group, UiO. Internal Report 2016 Department of Physics, The Faculty of Mathematics and Natural Sciences, University of Oslo, 52 p.— www.mn.uio.no/fysikk/tjenester/kunnskap/straling/radon-­and-­lung-­cancer.pdf

8 The Usefulness of Radiation Low Doses: Radiation Hormesis

8.1 What Is “Hormesis” In the first approximation, our world is linear. In the well-known basic laws of nature—Newton’s law, Ohm’s law, Hooke’s law, and many others—there is a linear relationship between the impact and its result. Acceleration is proportional to the force (this is Newton’s law), current is proportional to electrical stress (this is Ohm’s law), deformation is proportional to mechanical stress (this is Hooke’s law), and so on. Deviations from linearity occur only with increasing exposure intensity. This is how, for example, shock waves appear. However, in the case of living matter, the situation with linearity is entirely different. Evidently, nonlinear effects arise in the action of various factors on living matter even at the lowest intensities. In the second half of the XIX century, first, the German scientist Eduard Pflüger established the patterns of influence on the muscle of electric current. Rudolf Arndt, professor of psychiatry at the University of Greifswald, extended Pflüger’s results to all irritations. Finally, in 1888, a professor of pharmacology at the same university, Hugo Schultz, formulated the provisions, which turned into a general biological law, known as the Arndt-Schulz rule: Arndt–Schulz rule: For every substance, small doses stimulate, moderate doses inhibit, and large doses kill. Otherwise, depending on the intensity of the impact, the effect changes sign. A strong influence is harmful, and a weak one of the same factors exhibits beneficial effects. The stimulating, beneficial effect on the body systems of any external agent that exhibits a damaging effect in large doses is called “hormesis.” One of the © The Author(s), under exclusive license to Springer Nature Switzerland AG 2023 I. Obodovskiy, From Radio-phobia to Radio-euphoria, Springer Praxis Books, https://doi.org/10.1007/978-3-031-42645-2_8

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Health status

Threshold Hormesis Low doses Natural background

High doses Damaging effect

Absorbed dose or dose rate

Fig. 8.1  Dose–response plot showing the region of hormesis. In various cases, on such graphs, a positive health effect is plotted along the y-axis, then the hormesis region looks like a convex part of the curve, as shown in this graph. Sometimes, on the contrary, the lesion of the organism is postponed along the y-axis, and then, hormesis is depicted by the concave part of the curve, as shown, for example, in Fig. 6.9

options for a schematic representation of the hormesis phenomenon is shown in Fig. 8.1. The word “hormesis” comes from the Greek verb “hormo,” meaning rapid movement or striving. In particular, the well-known word “hormone” comes from the same root. The agent that causes the effect of hormesis is sometimes called “hormetin.” In this book, hormetin is ionizing radiation. In many branches of biomedical sciences, including toxicology, pharmacology, and others, the effects of hormesis have long dominated. The dose– response relationship with hormesis (Fig.  8.1) becomes a universal model, regardless of the biological object, the effect being measured, and the chemical and physical properties of the agent whose action is being analyzed. Hormesis is a general version of the reaction of various organisms, not only humans, to irritation.

8.2 Chemical Hormesis The idea of chemical hormesis appeared at the end of the XIX century when dozens of experiments described the positive effect of various metals and chemical compounds on the growth and development of plants, fungi, algae, and bacteria. At the same time, it was already known that, in large doses, these substances inhibit the development of organisms. The term “hormesis” was proposed back in the 1920s.

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It has been known since antiquity that there are no (or almost no) absolutely toxic substances. Most substances we call poisonous can be harmless, useful, or even necessary for the normal development and functioning of the body in certain doses. The human body is built from four basic elements (C-carbon, H-hydrogen, O-oxygen, N-nitrogen) and eight macronutrients (Ca-calcium, K-potassium, Mg-magnesium, Na-sodium, P-phosphorus, S-sulfur, Cl-chlorine, F-fluorine). The four main elements make up 96% of body weight. But besides this, the body needs ten so-called trace elements (Al-aluminum, Co-cobalt, Cr-chromium, Cu-copper, Fe-iron, I-iodine, Mn-manganese, Mo-molybdenum, Se-selenium, Zn-zinc). Trace elements are, as a rule, part of compounds that facilitate their participation in metabolic processes. But this is not the end of human needs. In addition to the above, experts distinguish conditionally essential (vital, but harmful in certain doses) microelements (Ag-silver, Au-gold, B-boron, Br-bromine, Co-cobalt, Ge-germanium, Li-lithium, Ni-nickel, Si-silicon, V-vanadium)—10 elements in total. The remaining elements in nature are classified as conditionally toxic microelements and ultra-microelements. Mercury (Hg) is believed to be harmful to humans in any amount, so it can be called an unconditionally toxic element. The most obvious example is arsenic (As). Probably, in the history of humankind, there was no chemical element with such a sinister reputation. Arsenic has traditionally been associated with poison. Much attention was paid to him by writers. As is known, the number of victims of this element in all literary works probably exceeds the number actually destroyed. If the hero of Agatha Christie died due to poisoning, it was usually arsenic. The toxicity threshold, the minimum dangerous amount of arsenic, is at ~5 mg per day; a dose of 50 mg or more can be fatal. However, in small doses, arsenic is necessary because it performs several important functions in the body. Arsenic controls phosphorus exchange and participates in the oxidative processes occurring in mitochondria. According to various sources, the daily need for arsenic is 50–100 μg. In the general case, the effect of trace elements on the body is well illustrated by the graph in Fig. 8.2. Not only trace elements but also vitamins and hormones, when a certain dose is exceeded, can cause dangerous consequences, although they are necessary in small doses. In addition to the vital need for vitamins, hypervitaminosis is also known. An excess of some vitamins, such as A and D, leads to serious diseases. In some cases, the symptoms of hypervitaminosis are similar to acute poisoning.

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Health status

Optimal

Poisonous

Deadly

Deadly

Insufficient

Consumption

Fig. 8.2  Biological action of an arbitrary microelement

Many strong poisons are stimulating and healing at low doses or concentrations. Chemical carcinogens can suppress cancer at low doses. The example of oxygen toxicity can illustrate the controversial role of almost any element. In diving practice, it is well known that oxygen, without which it would seem impossible to live, at a partial pressure exceeding normal, can have a toxic effect on the body. During the Second World War, many lives were saved by the first antibiotic discovered shortly before—penicillin. But penicillin was not enough, and doctors, trying to save a rare medicine, reduced its doses. It turned out that in small doses, penicillin has the opposite effect: not only does it not suppress, but, on the contrary, it stimulates the growth of staphylococci. There is no doubt about the usefulness of moderate consumption of alcohol, caffeine, or nicotine. At the same time, large doses of these substances can be very dangerous or even fatal. The alcohol example is quite popular. The well-known radiobiologist Zbigniew Jaworowski wrote that although a gallon of alcohol is an almost lethal dose, a sip of cognac is likely to have a beneficial effect on the human body. Excess sugar in the diet is harmful, but a certain sugar intake is necessary. An excess of salt is also harmful, but one cannot live without salt at all. The situation is similar with nutrition in general, overeating is harmful, and it leads to obesity, but malnutrition is also harmful; it leads to loss of bone and muscle tissue, weakness, and problems with general physical and intellectual development. Intense sunlight leads to burns and can cause skin cancer. Still, a certain insolation is necessary, vitamin D is produced in the body under sunlight, and a light tan is healthy, beautiful, and helps to harden the body.

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Hard, grueling work exhausts the body, but a certain physical activity is necessary. Many more examples could be given, but the main idea is clear. Hormesis manifestations have been observed in medicine, molecular biology, pharmacology, nutrition, agriculture, microbiology, immunology, toxicology, aging, physiology, and carcinogenesis, i.e., in almost every branch of biology. To date, the ideas of hormesis have been taken quite seriously by the scientific community and are being intensively developed.

8.3 Law of Tolerance Let us give one more example of a nonlinear connection, which is a universal law of nature. In ecology, it has long been established that any factor in excess or deficiency can limit the growth and development of organisms and populations. These factors can include heat, light, water, nutrients, oxygen content, exercise, sunlight, and many others. The German scientist Justus von Liebig., who in 1840 formulated the so-called Liebig’s law of the minimum, pointed out the role of the lack of some factors. Later, in 1913, the American zoologist Victor Shelford generalized and supplemented this law called “The Law of Tolerance.” In sum, these two laws state that each organism is characterized by a minimum, maximum, and optimal environmental factor value, which determines the area of normal life activity. These limits are shown in Fig. 8.3. It can be seen from the graph that factors intolerable at high doses for living organisms and at lower doses turn out to be quite useful for normal life

Death

Upper limit

Lower limit

Zone of favorability of a factor

Endurance limits

Zone of oppression

Zone of normal activity

Zone of oppression

Death

Intensity of a factor

Fig. 8.3  Dependence of life potential on the intensity of impact factors

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activity or even necessary. As Liebig pointed out, the lack of such factors can also be harmful. Pay attention to the similarity of the graphs in Figs. 8.1, 8.2, and 8.3 on the one hand and the small difference on the other. In Fig. 8.2, the optimal zone is rather extended; in Fig. 8.3, it is much narrower.

8.4 Radiation Hormesis Hormesis is also manifested under the influence of ionizing radiation on living organisms. The idea of radiation hormesis was introduced in 1980 by the American scientist T. D. Lucky; it means the beneficial effects of small doses of radiation.

8.4.1 T.D. Luckey Thomas Donnell Luckey, 1919–2014, is the founder and active promoter of the ideas of radiation hormesis, therefore, in the corresponding section, he should be given some special attention. In 1980, Lucky published the book “Hormesis with Ionizing Radiation,” which actually introduced the concept of “radiation hormesis” into scientific circulation. In more than 1200 reports that were summarized in the book, Luckey validated radiation hormesis. He wrote “Statistically significant results with microorganisms, plants, invertebrates and experimental animals demonstrated radiogenic metabolism (metabolism promoted by ionizing radiation) is an important life function. Low dose irradiation of microorganisms induced increased respiration, enzyme induction (adaptation), metabolism, resistance to killing doses, and cell division. Chronic whole-body exposures to low doses of ionizing radiation increased reproduction, growth, maturation, and development, resistance to disease, resistance to lethal doses of radiation, and average lifespan. Radiation hormesis in immunity is especially important.” In particular, Lucky noted that the positive effect of radiation exposure was discovered almost immediately after the discovery of radiation back in 1896. Professor W.  Shrader infected guinea pigs with diphtheria bacilli at the University of Missouri. Non-irradiated animals died after about 24  hours, while those irradiated with X-rays survived. Research carried out simultaneously revealed the beneficial effects of radiation on infectious damage to the body, wound healing, and other adverse health effects.

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In 1991, a new book was published, which was called “Radiation Hormesis.” This book reviewed stimulation in mammals and humans by low doses of ionizing radiation. The main criteria were less disease (especially cancer), longer life spans, and improved (more abundant and more healthy) reproduction. Lucky was one of the first researchers to show in special experiments in a low-background laboratory that the growth rate of rats and mice decreases with a reduced level of radiation. About life activity in conditions of the reduced radiation background, see Chap. 10. Currently, hundreds of famous scientists support the idea of radiation hormesis, but Professor T. Lucky was the first. His results and ideas turned out to be pivotal. According to Lucky, the current level of external exposure (~1 mSv/year) is quite sufficient for a normal life, but more is needed for optimal health. Most humanity, according to Lucky, lives in conditions of radiation deficiency. The optimal value is about 60  mSv/year, and the boundary value above which doses are harmful is several Gy/year. Lucky takes an extreme position: Humanity does not have enough radiation for a prosperous life. In his opinion, the population, which lives in conditions of an average radiation background, must also be additionally irradiated. In his opinion, additional exposure improves health, increases fertility, activates the immune system, reduces the frequency of deaths due to cancer and infectious diseases, and lengthens life. Lucky estimates that adequate exposure to ionizing radiation can reduce cancer deaths by 5% of today’s levels. The benefit of such radiation is to activate the immune system. Professor Lucky lists many more beneficial effects of irradiation, but the main result is increased duration and quality of life. Lucky’s ideas were enthusiastically received by Japanese scientists, who are suspicious of radiation for obvious reasons. In 2003, Lucky was invited to a symposium in Tokyo, where he was awarded the honorary title of “samurai,” and shortly after that, he was presented with a magnificent sword and an authentic samurai uniform, shown in the photo of Fig. 8.4.

8.4.2 Justification of the Idea of Hormesis At first glance, the existence of a hormesis region may seem paradoxical. Indeed, the immediate impact of ionizing radiation on any substance is destructive. Radiations are called ionizing because they tear off electrons from an atom and turn neutral atoms into ions, destroying atoms. Naturally, doubts arise about how a primarily destructive effect can result in a favorable, healing

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Fig. 8.4  Sir Samurai T.D. Lucky at his home in Kansas in 2005 in a special samurai outfit presented to him. There is reason to believe that Professor Lucky was proud of his samurai title. Photo from: T.D. Luckey. Sir SamuraiT.D. Luckey, Ph.D. Dose-Response, 6 (1) 97–112, 2008—https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2477726/ Courtesy of the National Library of Medicine

effect. Let us explain this with well-known examples. It is easy to remember that many remedies cure while inflicting a certain defeat. In treating pneumonia, banks leave extensive bruises on the body, usually on the back. Colds are treated with mustard plasters, which cause local inflammation. From the history of medicine, bloodletting, staging of leeches, and some other unpleasant treatment methods are known. The so-called fever is officially recognized as a therapeutic method in which a seemingly dangerous phenomenon occurs—the body temperature rises significantly. The Austrian physician Julius Wagner-Jauregg used fever to treat

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syphilis in the early twentieth century. He caused a fever by infecting a patient with malaria. The fact is that the causative agent of syphilis, Treponema pallidum dies at temperatures above 39 °C. And if the body temperature rises above this seemingly dangerous limit, the pathogen dies as a result of fever. Even earlier, Wagner-Jauregg proposed using “fever” therapy to treat progressive paralysis, multiple sclerosis, and schizophrenia. He was awarded the Nobel Prize in Physiology or Medicine in 1927 for these achievements. The impact of low radiation doses can be considered an irritant and stimulating factor and can be compared, for example, with acupuncture. Charged particles, like small needles, bombard the body’s cells and force them to defend themselves. Apparently, mainly because of the paradoxical nature of the favorable effects of radiation, the idea of hormesis, and even just the threshold of stochastic effects, is resisted by many specialists and “official” bodies. Whether it is time for regulatory organizations to consider the phenomena of hormesis in policy documents has become the subject of heated discussions. To date, a huge amount of experimental and observational material has been accumulated, showing that, under the influence of radiation, the manifestation of hormesis in the “dose-effect” dependence is quite real. All living things arose, lived, and developed in the conditions of a natural radiation background. There is reason to believe that radiation was one of the physical factors necessary for the emergence of life on Earth and the creation of various forms of living organisms. Moreover, billions of years ago, at the time of the emergence of the first organisms, background radiation was about 3–5 times greater than today. The whole history of the emergence and evolution of all living things and, in particular, man, proceeded under the constant influence of the natural radiation background of cosmic and terrestrial origin. No living organism has developed an organ sensitive to ionizing radiation. However, organs appeared and developed with amazing sensitivity and resolution to many other external influences—visible and thermal radiation, sounds, smells, vibrations and taste sensations, and magnetic and electric fields. There is no doubt that if this were required during evolution, i.e., if the sensitivity to ionizing radiation had any adaptive meaning, then such an organ could well appear. But evolution has developed powerful defense systems in the human body. A system for restoring or removing damaged molecules and cells (repair of DNA and membrane damage, regulation of intercellular relations, apoptosis, etc.) has been developed and genetically fixed. The vast majority of DNA damage in humans is spontaneous. It occurs due to the thermal movement of molecules and is also induced by free radicals

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formed in the processes of oxygen metabolism. Each mammalian cell experiences about 70 million spontaneous DNA damages per year. Only a powerful and efficient reparative mechanism allows a living organism to survive with so much damage. Ionizing radiation also damages DNA, but much less frequently. With the current average natural radiation background of 2.4  mSv/year, radiation is responsible for no more than about 5 DNA damages in one cell per year. From the harmful effects of radiation in a relatively wide range of doses, a person is protected by the body’s protective mechanisms. Low-dose radiation triggers repair mechanisms and becomes efficacious not only against radiation-induced damage but also against damage from other stressors. Therefore, these mechanisms may cause an overall improvement in health, including cancer suppression. Above, we talked a lot about the existence of hormesis and justified its existence with various analogies, it is time to demonstrate real cases of hormesis manifestation.

8.5 Experiments on Bacteria, Tissue Cultures, Rodents, etc. It must be understood that in the case of bacteria, fungi, and even plants, radiation induces not cancerous tumors but cell death or mutations. In higher animals and humans, mutations cause cancer, but the relationship between mutations and an actual malignant tumor is complicated. Only in experiments on animals can one obtain information about the induction of malignant neoplasms by radiation, but these data could also be transferred to humans with great caution. Nevertheless, meaningful information about the effect of radiation on living tissues is obtained by working with all possible living objects, starting with bacteria. About the results of experiments on these diverse systems, we will briefly report below, but the leading interest for us is experiments on animals, mainly on rodents. This book describes the effects of radiation on humans, and this chapter is about the manifestation of hormesis in such exposure. However, beforehand, very briefly, it is useful to talk about the extensive material on hormesis, which was obtained in experiments on various biological objects, more simple than a human: bacteria, plant seeds, fungi, tissue cultures, insects, rodents, and other animals. A detailed analysis of studies of such objects before 1980 is given in the book by T.D. Lucky.

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The diversity of living organisms is caused by the desire to understand the degree of universality, or vice versa, the selectivity of the detected patterns, in particular, hormesis. In addition, the researchers also solved practical problems—to discover the possible beneficial effects of radiation for its use in agriculture or industry. The results to date convincingly prove the existence of a region of hormesis in a certain dose range for many relatively simple organisms. In particular, extensive studies confirming the existence of hormesis have been performed on human lymphocytes. In most cases, an increase in life span, fertility, and growth was observed. Irradiation also increases the resistance of organisms to any adverse external influences, such as heat stress, oxygen attack, or starvation. So, for example, if a classic model organism—E. coli (Escherichia coli) is placed on a non-­ nutritious medium, it will gradually die of starvation. But if at the same time, it is irradiated with ionizing radiation, then the aging and death of cells slow down significantly. The lowest survival rate of E. coli bacterial cells was observed under natural background radiation (0.15 μGy/h). With increasing dose, survival increases, and this effect is manifested even if the dose rate of chronic exposure exceeds the natural background by 10 thousand times. A similar result was also obtained on another classical model object, more complex, on unicellular fungi, baker’s yeast (Saccharomyces cerevisiae). Naturally, it was necessary to expand the groups of objects toward more complex ones, located on the evolutionary tree closer to humans. Studies have been conducted on many types of animals—various rodents, rabbits, and even dogs and monkeys. Most information was obtained on a classic experimental object—on mice. Under irradiation with a dose rate of 3 Gy/year ~10 mGy/day, the growth rate of mice was higher than that of non-irradiated individuals by almost 30%. So, mice that grew and reproduced safely received about one thousand times the doses of radiation that humans receive. At higher doses, up to a dose of at least 1 Gy, the likelihood of leukemia (yes, mice can get leukemia) and lung cancer decreased, and life expectancy increased. It is pleasant to note that in experiments with mice in which hormesis is manifested, experimental mice do not suffer, but rather develop better, live longer, and get sick less. Experiments were also carried out on dogs. For example, the greatest increase in dog lifespan was observed at a dose rate of ~50  mGy/year. In another experiment, beagle dogs were injected with strontium-90, if the total dose during their lifetime did not exceed 10 Gy, the risk of bone sarcoma was noticeably lower than in the control.

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And finally, it is necessary to note the practical benefits of the effects of radiation on organisms. The beneficial effect of pre-sowing seed irradiation has long been well known—accelerating the growth and development of plants, reducing the growing season, increasing the yield, as well as improving its quality (increasing the sugar content of sugar beets, protein in cereals, starch in potatoes, useful alkaloids in medicinal plants, vitamins in fruit and vegetable crops). Under the action of X-ray and gamma rays in doses of 1.0 and 1.5 Gy, the germination of seeds increases by an average of 20–60% compared to the control.

8.6 Survivors of the Hiroshima and Nagasaki Nuclear Bombardment 8.6.1 Cancer The results of epidemiological studies of a huge cohort of survivors of the atomic bombing of Japanese cities, showing the safety of low doses of radiation, are given in Sect. 7.4. But in the research materials, there is information about the usefulness of small doses, about hormesis. Moreover, looking for this information “under the microscope” is unnecessary. They are presented in many works by reputable scientists, including Japanese ones. Professor Emeritus of Biology at Osaka University, Dr. Sohei Kondo, in a 1993 book titled “The Health Effects of Low-Dose Radiation,” has written that “Bomb survivors outlive their non-irradiated peers.” The frequency of deaths from all types of cancer for people over 60 years old, i.e., at the time of the bombing, they were over 20 years old, turned out to be significantly less than the frequency of deaths in a similar age, but not exposed group of people who were lucky enough not to be in the city on the day of the bombing. According to Dr. Kondo, the range of useful or at least safe doses extends as far as 2 Sv. The title of an article by the Japanese scientist Shizuyo Sutou is characteristic: “Low doses of radiation from atomic bombs increase life expectancy and reduce mortality from cancer compared to unexposed people.” In another article, he wrote: “The survivors of the atomic bombing are less likely to get cancer and live longer.” A similar result is noted by Nagasaki University biologists Mariko Mine and colleagues in an article with a telling title: “Obviously beneficial effect of

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low to intermediate doses of radiation from an atomic explosion on health.” According to Mariko Mine , life expectancy in all age groups was noticeably longer than expected. An analysis of the detailed data for 1950–2003 on the condition of survivors of the atomic bombings contained in Report No. 14 of a group of specialists from the Hiroshima Research Center (Kotaro Ozasa et al.) shows that the dependence of additional relative risk from the dose, hormesis is observed. The result of this work is shown in Fig. 8.5.

8.6.2 Leukemia Response Very important are results concerning leukemia dose—response. It is known that the most radiosensitive organs and systems in humans are bone marrow. So, it means that the hemopoietic cell system in mammals is generally more radiosensitive than others, and therefore, radiation-induced leukemia is expected to occur at lower doses and much sooner than other radiation-­ induced cancers. So, the dose–response behavior for leukemia would indicate the likely dose-response for these other cancers. A recent analysis of the occurrence of leukemia among more than 95 thousand survivors of the Hiroshima bombing showed that only those who 1.2

Excess Relative Risk

1 0.8 0.6 0.4 0.2 0 -0.2 -0.4 0

0.5

1

1.5

2

2.5

3

Dose, Gy

Fig. 8.5  Additional relative risk for all solid cancers for atomic bomb survivors. It can be seen from the graph that the larger the dose, the greater the errors plotted on the graph because the larger the dose, the fewer people who received this dose. Figure on the basis of M. Doss. Evidence Supporting Radiation Hormesis in Atomic Bomb Survivor Cancer Mortality Data. Dose-Response. 10 (4) 584–592, 2012—https://www.ncbi.nlm. nih.gov/pmc/articles/PMC3526329/

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100000 10000 1000

LNT Model UNSCEAR 1958 data

100 10 0,0001 0,001

0,01

0,1

1

10

100

Dose, Sv

Fig. 8.6  Total number of leukemia cases per million versus radiation dose in the Hiroshima survivors for 1950–1957. On the basis of UNSCEAR 1958. Annex G, p. 165, Table VII with ref. to N. Wald, Science 127, 699–700, 1958

received a dose greater than 1.1 Sv developed leukemia (Fig. 8.6). At doses below the threshold, the number of cancer cases is less than at very low doses of ~0.1 mSv, which means that when leukemia is excited by radiation, there is a region of hormesis. The well-known publicist Ed Hiserodt summed up the section on hormesis in the Japanese cohort in his book “Underexposed”: “To date (this is written in 2017), most Japanese scientists and a significant part of the population are confident in the increase in the life expectancy of surviving bombardment victims.”

8.7 Occupational Exposure As far as humans are concerned, practically for each of the cohorts described in Chap. 7, where the safety of low doses of radiation is shown, there is information about their usefulness, i.e., the manifestation of hormesis in the dependence “dose-effect.” In epidemiological studies of the impact of low doses of radiation on health, all possible types of exposure and, accordingly, the types of cohorts are divided into two groups: Occupational exposure—everyone who receives increased doses at work. Environmental exposure—population forcedly exposed to increased doses of radiation.

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Occupational exposure includes radiologists, employees of nuclear enterprises, military personnel in nuclear weapons testing zones, accident liquidators, crews of spaceships, and long-range aircraft. Environmental exposure—patients undergoing diagnostic and therapeutic radiation procedures, the population near test sites and nuclear enterprises, the population in accident zones, particularly Chernobyl and Fukushima, and residents of areas with an increased natural radiation background. For various reasons, all these people usually received and continue receiving radiation doses exceeding the natural radiation background for quite a long time. The effect of radiation on their health has been studied in detail for a long time, and by now, the beneficial effect of small doses has been reliably established. We will tell here about some obvious examples of the manifestation of hormesis.

8.7.1 Nuclear Shipyard Workers Let’s start with a study of the health of nuclear shipyard workers. The work was carried out during 1980–1988 under a contract with the US Department of Energy. It was expected the study would show a slight increase in the proportion of cancers. However, studies have reliably shown an apparent reduction in mortality, not only from cancer but from many other diseases. Since the results turned out to be the opposite of the official concept adopted then, the research results were not published and are known from the articles of one of the members of the Technical Advisory Commission, the famous American scientist John Cameron. Professor Cameron is the author of many articles and several books; he attained many honors throughout his distinguished scientific career; he was a Charter member of the American Association of Physicists in Medicine (AAPM) and in 1968 served as its President. The nuclear shipyard worker study (NSWS) is the world’s largest and most thorough study of the health effects of low-dose-rate ionizing radiation on nuclear workers. It was a rigorously performed search for health risks of radiation to civilian employees of eight shipyards (2 private and 6 public) that overhauled and repaired nuclear-propelled US Navy ships and submarines located on the Atlantic, on the Pacific coast, and in the middle of the Pacific Ocean, in Hawaii. Several features distinguish these studies from others of their kind.

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First, the large size of the cohort and control groups enabled a strong statistical power in the study. Exposed cohorts and controls were selected from nearly 700,000 shipyard workers, of which over 100,000 had dealt with radiation in nuclear shipyards. The researchers selected a group of almost 28,000 workers who had accumulated a dose of more than 5 mSv by January 1, 1982, and a group of more than 10,000 for whom the accumulated dose did not exceed 5 mSv. The control group included over 32,000 people selected from approximately 600,000 non-nuclear shipyard workers who had no exposure to radiation during their work, carefully selected by age, duration, and working conditions to fit the exposed cohorts best. Second, reliable dose determination. It was already mentioned in Chap. 7 that for many cohorts, the determination of accurate doses is a complex problem, and there needs to be more confidence in the reliability of the determination. This is especially true for populations exposed to elevated doses under various circumstances. Often, the doses of professionals are determined with significant errors. For example, teams of liquidators in the Chernobyl accident received one dosimeter per group. For all group members, the same dose was written, although the work performed could vary significantly. In the case of the nuclear shipyard study, dose assessment was unusually accurate because the Nuclear Navy program had substantial discipline in assigning radiation-monitoring badges and in accurate recording of results. A quote from the Final report illustrates the quality of the dose determination: “In summary, all data of radiation exposures to shipyard workers in the Navy nuclear propulsion program have indicated that doses are accurately recorded, carefully monitored, and are a true reflection of the dose received by the marrow which makes this population ideal for studies of effects of low-­ dose radiation.” Third, exposure to one type of radiation. Members of many cohorts are exposed to mixed radiation. These can be gamma quanta, neutrons, protons, and heavier nuclei, such as alpha particles. Different types of radiation have different effects on the body, so the analysis, interpretation, and comparison of the results are complex. The cohort of nuclear shipyard workers compares favorably here as well. Nuclear shipyard workers were primarily exposed to external 60Co gamma rays resulting from neutron activation of cobalt in the reactor that was deposited in pipes and valves associated with the reactor cooling systems, i.e., low LET radiation. When selecting cohorts, investigators did not include individuals if they suspected they might have been exposed to high LET or

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internal radiation. Eliminating confounding from high LET radiation or internal doses permits comparison with other large groups of radiation workers exposed to low LET radiation, such as radiologists and radiology technologists. Fourth, the “healthy worker effect” was eliminated. The selection of cohorts and controls solved a problem that had reduced the reliability of the results of many other studies of the effects of radiation on health, the so-called “healthy worker effect.” If the control group is selected from the general population, it may contain individuals too sick to work or commute. There are also fewer individuals with severe alcohol and drug abuse problems among the employee populations. In this study, the health of nuclear shipyard workers was compared with the health of workers in other, non-­ nuclear shipyards with a similar nature of work, differing only in the absence of increased doses of radiation. An additional circumstance that increased the reliability of the survey results was the absence of incentive payment for radiation work. This helped to avoid the possibility of a positive selection bias, with healthier and more skilled workers favoring a more profitable shipyard. Fifth, exposures to job hazards such as chemicals and asbestos were similar between nuclear and non-nuclear workers. Sixth, seventh, etc. For a long time, one can list the main advantages of nuclear shipyard worker study. Still, I ask readers to believe the author, who carefully studied the study materials, that the nuclear shipyard worker study is the most reliable study of the health effects of low-dose-rate ionizing radiation.

8.7.2 Health of Shipyard Workers Standard shipyard dose rates were 0.5–22.5 mGy/y, and few workers exceeded 50 mGy/y. The average shipyard dose rate of ~7.6 mGy/y is somewhat higher than most natural background levels worldwide (average ~ 2.4 mGy/y). The study determined mortality from 21 single types of cancer, as well as from non-cancer diseases: diseases of the circulatory, respiratory, digestive, and nervous systems, infectious diseases, mental illnesses, and external causes. But we will not bore the reader with such detailed information. The summary result—in the irradiated cohort, mortality from all causes was less than in the control group by 24%. A 24% lower SMR implies a 2.8-year increase in average lifespan.

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The study results are shown in the graph in Fig. 8.7. In the control group, mortality was close to the average mortality in the country. In the second group (5 mSv), it was 76%. It can be seen from this that mortality from all causes in exposed workers was noticeably lower than in non-exposed workers. Mortality was also significantly lower in the exposed group apart from respiratory, cardiovascular, and cancerous diseases. So, nuclear workers were in better health and less likely to get cancer than the general population. Radiation exposure can decrease not only the probability of cancer events but of many other diseases. The high quality and robust nature of the studies on the health effects of low doses of radiation on the health of nuclear shipyard workers make these studies a benchmark with which studies on other cohorts with similar types of exposure are compared.

8.7.3 Radiologists Radiologists are a large cohort receiving exposure close in composition to that of a shipyard cohort because both for diagnostic and therapeutic purposes,

Relative mortality

1,2 1,0 0,8 0,6 0,4 0,2 0,0 Control

< 5 mSv Accumulated dose

> 5 mSv

Fig. 8.7  Relative mortality of nuclear shipyard workers divided into three groups according to accumulated doses. The non-nuclear control group included 32,510 people. The second group consisted of workers whose accumulated dose did not exceed 5 mSv. In this group, there were 10,348 people; the standardized mortality ratio for this group was equal to 81% of the control group. The third group consisted of workers whose accumulated dose exceeded 5 mSv; it included 27,872 people 70,730 people in total. The standardized mortality rate for the third group was equal to 76% of the control group. Figure on the basis of Sponsler R, Cameron JR. Nuclear Shipyard Worker Study (1980–1988): a large cohort exposed to low-dose-rate gamma radiation. Int J Low Radiat. 1, 463–478, 2005—http://www.ecolo.org/documents/documents_in_english/low-­dose-­NSWS-­shipyard.pdf

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X-ray and gamma quanta, i.e., low LET radiation, are mainly used. Perhaps readers know that radiation therapy uses both protons and heavy ions, and pions and neutrons, and even the possible advantages that antiproton therapy can provide are discussed. However, these types of radiation comprise a small proportion of the total volume of radiation procedures. Second, radiologists are still affected by well-penetrating X-ray and gamma radiation in all cases. The results of a large set of epidemiological studies of radiologists showed that after 1950, the work of radiologists became practically safe. For more information, see Sect. 7.5. Moreover, the morbidity and mortality of radiologists turned out to be less than could be expected in general for the population. Radiologists have reduced mortality not only from cancer but from all other causes in general. In other words, those small doses, but more significant than the natural background to which radiologists were exposed, had a protective effect despite all the measures taken. Thus, the effect of low doses on radiologists leads to hormesis. An analysis of mortality for nine cohorts of radiologists and radiological technicians showed that in all cases, the mortality of radiologists is markedly less than that of doctors in all other specialties. The SMR for deaths from all causes for British radiologists who joined a radiological society from 1955 to 1979 was 32% lower than that of all male physicians in England and Wales, and 29% lower for deaths from all cancers. We recall that mortality from all causes in the shipyard cohort was 26% lower.

8.7.4 Nuclear Industry Workers In the United States, large teams of many laboratories and enterprises were examined: employees of the Oak Ridge and Los Alamos laboratories who have dealt with radiation since the time of the Manhattan Project, employees of the nuclear weapons production plant in Rocky Flat in Colorado, employees of the Rocketdin Atomics enterprise in California, all more than 100 thousand people. In all cases, morbidity and mortality among employees who received an accumulated dose of less than 50 mSv amounted to 60–80% of the total mortality of the population. A reduced cancer risk was also observed in a large cohort of Canadian nuclear workers. Workers exposed to doses in the 1–49 mSv range had a 70% cancer risk compared to those exposed to doses less than 1 mSv. In the UK, studies of the effects of radiation on the health of workers in the nuclear industry were carried out several times; each time, the number

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involved in the survey increased. In 1999, the total mortality among the cohort of more than 124 thousand people was 0.82 compared to the entire population, and in 2009, the cohort added another 50 thousand people and mortality from all causes and cancer was almost the same. Employees of the Mayak enterprise living in the city of Ozersk were subjected to a detailed survey with international participation when the opportunity arose, i.e., after 1991. Although the accumulated doses were relatively high, mortality due to all causes was approximately 75% compared to the non-irradiated residents of Ozersk and even less, about 65% compared to the average mortality of the Russian population. Particular attention was paid to the alpha-particle irradiation of workers who inhaled plutonium-239 for a long time. The probability of lung cancer in 500 employees with accumulated plutonium content of more than 1 kBq was 60–80% compared to the control cohort.

8.7.5 Chernobyl and Fukushima An analysis of the tragic events in Chernobyl and Fukushima also shows that in the group of liquidators who worked in the 30-kilometer zone in 1986–1987 and received doses of less than 100 mSv, the incidence of cancer was ~30% less than the average for Russia. There was also a decrease in cancer incidence among the population (by 5%). Thus, hormesis also occurred for the liquidators, who received a low dose. Not much time has passed since the Fukushima accident on the scale of the latent time of cancer induction, but here, too, researchers note hormesis effects among the liquidators who received less than 250 mSv.

8.7.6 Military Observers The situation with military observers of nuclear explosions is like that with radiologists. Veterans who participated in the early period, when the tests were atmospheric, had insufficient understanding of the danger, and the methods of protection were primitive, i.e., until 1963, there was a marked increase in mortality from all types of cancer. In the subsequent period, although the doses received by observers decreased significantly but still remained above the usual natural radiation background, a decrease in mortality from cancer was registered for observers of nuclear explosions from the

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United States (32 thousand people) and England (22 thousand people). The overall mortality of Canadian military observers was 88% of controls, and mortality from leukemia was 40%.

8.7.7 Radiation Effects on Long-Distance Flight Crews A description of various sources of cosmic radiation is given in Sect. 7.10. At an altitude of 10–12 km, where the routes of modern jet airliners lie, at middle latitudes, the absorbed dose rate is two orders of magnitude higher than the dose rate on the earth’s surface. This creates an enlarged background in aircraft cockpits. The dose field in the subpolar regions is several times larger. In addition, the intensity of irradiation depends markedly on solar activity. To date, significant information has been accumulated on the radiation conditions in flights, both on conventional and on supersonic aircraft. Aviators from seven European countries formed a large cohort, for which the mortality of crew members was studied. For approximately 17.5 years of observation, the loss of aviators from all causes amounted to about 0.7 of the standardized mortality of the population. All types of cancer showed mortality significantly lower than standardized, and only for leukemia, there is a slight excess over one.

8.7.8 Radiation Effects on Cosmonauts Much time has passed since the beginning of the space age, a significant number of cosmonauts, astronauts, and taikonauts have been in orbit and flight to the Moon, and some of them have spent a long time in outer space. Therefore, from previously published risk calculations and forecasts, the researchers moved on to analyzing the real state of health of people who have been in space. It should be noted that astronauts in terms of their biomedical indicators, noticeably differ on average from the country’s population. Astronauts have better health, higher income, education, regular exercise, and thorough and high-level medical care. The combination of these features is called the “healthy worker effect” for other cohorts. Therefore, it is more correct to compare them not with the population but, for example, with astronauts who have not yet flown, astronauts who have flown to the Moon, with astronauts who have flown in low orbits.

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In addition, it should be noted that several unrelated factors affect the health of space flight participants. In this book, we mainly pay attention to cosmic radiation, and the major health disorder is cancer. But in addition to radiation, weightlessness plays a massive role in space flight, as well as nervous tension associated with the preparation, waiting for a flight, unusual conditions, and other similar circumstances. Weightlessness and stress are assumed to be the most dangerous for the cardiovascular system. Therefore, it is important to study not mortality from any cause in general but separately from mortality from cancer, mortality from cardiovascular diseases, and mortality from external causes. External causes are accidents, drowning, electrocution, poisoning, burns, trauma, etc. The so-called standardized mortality ratio (SMR) was used to evaluate mortality. SMR is computed by dividing the observed number of deaths in a group by the number of deaths that would be “expected” in a similar reference population group. The mortality assessment of American astronauts was conducted on a cohort of 360 people who took part in space flights from 1959 to October 31, 2017. The mortality study among Russian cosmonauts included 262 people (194  in the Soviet period, 1960–1989, and 68  in the Russian period, 1990–2017). During this period, 80 astronauts and 96 cosmonauts died for various reasons. The result of the analysis of astronaut mortality showed that mortality due to cancer and cardiovascular problems in astronauts is noticeably less than the national average. On the contrary, the mortality due to various accidents and incidents is noticeably higher. For astronauts, over the entire observation period, mortality from cancer is 0.47 and from cardiovascular diseases—0.27. Astronauts are risky people; the mortality rate from any accidents is equal to 5.74. The mortality of Russian cosmonauts also turned out to be much less than the population for any reason and in any period. However, it is more than the death rate of US astronauts: for any reason, about twice. But mortality due to various fatal incidents among Russian cosmonauts and American astronauts is close. The result of the determination of the mortality of the US astronauts is shown in Fig. 8.8. For all diseases, it is less than the value for the ordinary population, for whom SMR = 100.

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100

Standard Mortality Rate

80

60

40 All natural

Cancer

20 Cardiovascualr disease 0

Fig. 8.8  Standardized mortality ratio (SMR) for all natural causes, cardiovascular diseases, and cancer among United States astronauts for the period 1970–2017. Normal SMR = 100. On the basis of R.J. Reynolds, S.M. Day. The Mortality of Space Explorers. Into Space, ed. by T. Russomano, L. Rehnberg, 2018, 296 p. https://www.intechopen. com/chapters/59553

8.8 Environmental Exposure 8.8.1 Patients of Radiation Medicine In Sect. 7.5, it was indicated that infrequent diagnostic procedures are perfectly safe, and it has been doubted that it may be worth guarding against multiple repetitive procedures. But in the report of A. Miller et al. with high statistical significance, a reduction in the relative risk of mortality from breast cancer in almost 32 thousand women who repeatedly underwent fluoroscopy between 1930 and 1952 was shown. Moreover, the risk dropped to 66% of control at a total dose of 0.15 Sv (Fig. 8.9).

8.8.2 Population in the Zones of Nuclear Weapons Tests The increased radiation background in some regions where the population is forced to live is formed for two reasons. First, these zones are contaminated due to nuclear weapon tests or near nuclear enterprises. Second, these are areas with increased natural background radiation. Studies of the health status of the population of these areas are described in Sects. 7.9, 7.11, and 7.12. The result of these studies is evident. Significant

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1000 800 600 400 200 0

0-0.1

0.1-0.2 0.2-0.3 0.3-0.4 0.4-0.7 3.0-6.0

Diapasons of doses, Gy

Fig. 8.9  Mortality from breast cancer per 100 thousand people per year after multiple fluoroscopic examinations of tuberculosis patients. Figure on the bases of Miller AB, Howe GR, and Sherman GJ. Mortality from breast cancer after irradiation during fluoroscopic examinations in patients being treated for tuberculosis. N. Engl. J. Med. 321, 1285–1289, 1989—https://pubmed.ncbi.nlm.nih.gov/2797101/

doses lead to various diseases, but if the doses do not exceed a certain threshold, then exposures are safe. Those cases in which information was received about the beneficial effects of small doses, i.e., about hormesis, are described in the current section. As a result of ground tests of nuclear weapons in the United States, the most polluted state was Nevada, in which, 105 km northwest of the city of Las Vegas, not far from the border with California, there was a nuclear weapons test site, as well as the states of Utah and Arizona, located to the east of the test site in the direction of the wind. See Sect. 7.9.3 for the nuclear explosions at the Nevada test site, the fallout from the explosions, and the health of the populations of nearby states. Detailed surveys of the population of the states of Nevada, Utah, and Arizona, exposed to radioactive fallout, began only in the late 70 s and early 80 s. Surveys revealed a significant increase in the incidence of various types of cancers: leukemia, thyroid cancer, breast cancer, etc., in people who received large doses of radiation. But the average lowest frequency of cancers was observed in the most polluted states—Nevada, Arizona, and Utah, with about 25–50 cases per 100 thousand of the population. In the rest of the states, which are flat and bypassed by tests or production related to radioactivity, the frequency of cancers is higher—up to almost 100 per 100 thousand of the population. The result of comparing the incidence of one of the types of cancer—lung cancer is shown in the graph in Fig.  8.10. Based on the results

Lung cancer incidence

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100 90 80 70 60 50 40 30 20 10 0 Normal

Infected Male

Normal

Infected

Female

Fig. 8.10  Number of lung cancer cases per 100,000 population in normal and radiation-­ infected US states. Figure on the basis of Lehrer S., Rosenzweig KE. Lung cancer hormesis in high-impact states where nuclear testing occurred. Clin Lung Cancer. 16 (2) 152–155, 2015—https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6587186/

obtained, the authors of the studies (S. Lehrer, K.E. Rosenzweig) conclude that low doses of radiation protect against lung cancer and do not cause it. Another reason for the difference in exposure conditions is the height of the location above sea level. The natural background in mountain regions is approximately twice that of Coastal Regions. But residents of mountain states have lower cancer rates than residents of Coastal Plain states. Additionally, life expectancies in mountain states are approximately one year greater than in Coastal Plain states.

8.8.3 Population Near Nuclear Facilities As a result of the famous Kyshtym accident, radioactive waste discharges into the Techa River, and wind drift of silt deposits from Lake Karachay, a complex radiation situation was created in the Southern Urals around the current Mayak enterprise (see Sect. 4.9.2). More than a hundred thousand people living in the floodplain of the Techa River in the Chelyabinsk and Kurgan regions were exposed to radiation. Some residents received significant doses of radiation, so significant that quite a few cases of chronic radiation sickness were recorded. The Mayak enterprise attracted close attention from Russian and foreign scientific communities regarding the accidents. Detailed surveys of the contamination of various territories and the state of health of personnel and the population have been carried out. Surveys over the next 30  years after the

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accident showed that residents of 22 villages who received doses less than 0.5 Gy significantly decreased mortality from various types of tumors to about 30% compared to the non-irradiated population. Some of the population has been exposed to chronic inhalation of plutonium-­239 due to accidents. For individuals who received up to 5  kBq of plutonium, the risk of lung cancer was significantly reduced compared to non-irradiated controls to about 50–60%. Thus, hormesis was observed for some of the affected populations who were lucky not to receive a large dose.

8.8.4 Life in Conditions of Increased Natural Radiation Background In Chap. 7, we named areas on our planet where the population lives safely in a significantly increased radiation background. In some places, due to the high concentration of radioactive nuclides of uranium, thorium, and radium; in others—due to more intense cosmic radiation. A more thorough analysis of the health status of the inhabitants of these areas gives grounds for asserting the manifestation of hormesis. So, in India, the Karunagapalli region, and China, the Yangjiang region, studies that captured large groups of the population showed that the incidence of cancer and mortality due to cancer is significantly less than in areas with a natural radiation background. There are areas in the southeast of France where the dose rate due to natural sources reaches more than 1 Sv/year. These areas are not inhabited, but French scientists (A. Léonard, M. Delpoux) have studied the life of mice. It turned out that mice in these areas showed an increase in fertility, an example of hormesis. The impact on the health of natural background radiation in the United States was studied in detail. In various works, attention was paid to various components of the radiation background: cosmic radiation, environmental radioactivity, in particular, increased as a result of human activity, emissions from nuclear weapons testing, accidents at nuclear installations, and the role of radon was taken into account separately. The height of the location above sea level determines the main difference in the magnitude of the cosmic background. It is clear that a large number of factors influence health and mortality. The surveys described in the articles by John Hart and colleagues considered several factors: smoking, altitude, education level, percentage of the population without health insurance, income,

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obesity, perceived health status, physical activity, and diet. It was found that the frequency of many diseases, particularly cancers, and cardiovascular diseases, is inversely proportional to the height and, consequently, the intensity of cosmic radiation. It is possible that with increasing altitude, the frequency of diseases of the heart and blood vessels is more affected not by radiation but by a reduced oxygen concentration. But in the case of cancer, non-altitude smoking is the dominant factor, followed by radiation intensity. Residents of mountain states have lower cancer rates than residents of Coastal Plain states, while the natural background (excluding dose from radon progeny) in mountain regions is approximately twice that of Coastal Regions. Additionally, life expectancies in mountain states are approximately one year greater than in Coastal Plain states.

8.9 Treatment with Low Doses of Radiation Another manifestation of hormesis is using low doses of ionizing radiation for treatment. One of the options for such treatment is the long and well-known radon procedures. This is covered in more detail in Chap. 9. Numerous examples in this chapter show that small doses benefit, reduce cancer risk, and prolong life, i.e., prevent the dangers of many other diseases. So small doses of radiation can treat. It is believed that the positive effect of small doses of ionizing radiation has been known since Herodotus and Hippocrates, who described the healing effect of radon sources. It is true that they, of course, did not suspect this action of radiation. But very soon after the discovery of X-rays and radium, as early as 1898, the stimulating effect of radiation was shown. In the first half of the twentieth century, radiation was successfully used to treat arthritis, pneumonia, and many other diseases. Radiation has also been useful in alleviating many inflammatory conditions: asthma, immune system disorders, etc. Such a dangerous disease as gas gangrene has also turned out to be subject to radiation. Studies up to 1940 showed that three X-ray sessions of 0.5 Sv were enough to reduce mortality from about 50% to only 5%. Much evidence of the therapeutic effect of radiation is collected in the articles of the famous American toxicologist Professor Edward Calabrese (Fig. 5.7). At the same time, reports of a possible side effect of such treatment—an increase in the frequency of cancers in patients treated with low doses, did not appear in the press. Ukrainian scientist Alexander Vaiserman provided the following evidence: “… X-rays and radium sources have been widely applied in the first half of the

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XX century for treating arthritis, pneumonia, and more. During the Manhattan Project, rodents exposed to inhaled uranium dust were studied. The scientists were surprised to learn that exposed animals were healthier and were characterized by higher life expectancy and more offspring than the controls. However, the dust concentration had been expected to be fatal at the experimental set-up. Later in 1958, the first United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) report provided experimental evidence for the longer survival of rodents such as mice and guinea pigs after exposure to low doses of gamma radiation and fast neutrons. These data have been interpreted as indicative of the existence of a threshold, but the hormesis was not mentioned.” A recent detailed review (2020) by Canadian physicist and entrepreneur Jerry M. Cuttler reports the successful treatment of more than 37,000 patients with various inflammatory diseases with low doses of radiation in the first half of the XX century. After the atomic bombing of Japanese cities at the end of World War II, and more specifically after the event with the Japanese tuna Fukuryu Maru described in Sect. 4.7 when the dangers of radioactive fallout became known to the whole world, the world was seized by radiophobia. And the use of low-­ dose radiation for treatment began to be reduced, forgotten, and even banned. In 1956, the US National Academy of Sciences (NAS US) recommended that radiologists stop using the concept of a threshold to determine the harmful effects of exposure. Doctors began to prescribe antibiotics and chemical drugs to patients, even for those diseases for which the beneficial and influential role of radiation had previously been proven. They were forced to avoid any use of radiation, including in every possible way to reduce the dose load during diagnostic procedures. At the official level, a linear non-threshold model began to dominate; the ALARA principle was in effect (see Sect. 5.7). Initially adopted in nuclear energy, this principle has been transferred to medicine, requiring radiologists to prescribe transillumination procedures only when necessary. The modern attitude to this principle in science is most clearly expressed in the article’s title by Canadian doctors Paul Oakley and Deed Harrison, “Death of the ALARA principle used in medicine,” published in 2020  in the journal “Dose— Response.” But this is a modern attitude, and not even universal, but then, in the middle of the twentieth century, low-dose radiotherapy practically stopped. In the second half of the XX century, especially after the discovery of the structure of DNA, biology experienced a period of extremely rapid development. Experiments were continued in laboratories with cellular material and

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with animals. The biological foundations of the beneficial effects of radiation on organisms were clarified. After some time, clinical experiments on the practical application of low-dose radiotherapy in medicine were resumed on a new basis. In the last 20  years, encouraging results have been obtained in treating many diseases with low doses of radiation, particularly cancer. A review by renowned biophysicist Myron Pollycove provides examples of 13 recent successful cases of low-dose X-ray treatment in Japan of patients with various types of stage IV cancer and those with serious autoimmune diseases. Japanese scientists from the University of Tohoku showed the possibility of suppressing metastases in treating malignant lymphoma by whole-body irradiation with doses of about 0.1–0.15 Gy (K. Sakamoto et al.). They relied on studies performed on mice. The result of such a study is shown in Fig. 8.11. So far, the statistics of cancer treatment with small doses of radiation are rather poor. Known results have been obtained on a limited number of patients. Thus, Sakamoto and co-workers conducted successful clinical trials of lymphoma treatment on 200 patients, showing that low-dose whole-body irradiation gives a significantly better result than conventional therapy methods. The idea of the action of radiation describes individual cases. One of Sakamoto’s colleagues was diagnosed with advanced ovarian cancer. She

Relative values of lung colonies

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Fig. 8.11  The relative number of metastases in the lungs of mice depending on the dose of total irradiation carried out 12 days after transplantation of cancer cells into mice. Figure on the basis of K. Sakamoto, M. Myojin, Y. Hosoi, Y. Ogawa, K. Nemoto, Y. Takai, Y.Kakuto, S. Yamada, N. Watabe. Fundamental and clinical studies on cancer control with total or half body irradiation. J. Jpn. Soc. Ther. Radiol. 9, 161–175, 1997— https://inis.iaea.org/search/search.aspx?orig_q=RN:29001443

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underwent a course of whole-body irradiation (1.5 Gy), which eliminated the malignant neoplasm. Another had advanced colon cancer, and this therapy successfully cured her. One of the patients had thyroid cancer that had metastasized to the lungs. The other malignant process was stopped by irradiation with small doses of the whole body. Elderly readers will be interested in cases of successful treatment of patients with metastatic prostate cancer. However, I wish young people to live to old age and, alas, to problems with the prostate; therefore, these cases should also interest them. Whole-body irradiation was used on two patients whose standard treatment did not give satisfactory results. Then, irradiation of the whole body with X-rays at 0.15 Gy once a week was applied. The PSA (prostate-­ specific antigen) value began to decrease after the first irradiation and, after the sixth session, reached a value of 0.085 μg/l. This is well below the dangerous level. Subsequent examinations showed that the metastases had disappeared. Notably, most of the research on treating low-dose radiation in our time is being carried out by Japanese biologists and doctors. This means that the Japanese, having behind them the experience of tragic nuclear bombings, not only are not afraid of radiation but also believe in its beneficial effect.

8.10 COVID-19 and Radiation At the end of 2019, a coronavirus pandemic broke out on planet Earth. The clinical picture of COVID-19 can manifest itself in 3 phases. A Patient’s immune system often copes with the first two phases, and the viruses disappear from the body. However, it can go into the third phase of acute respiratory syndrome for some patients. This hyperinflammatory phase requires supplemental oxygen and, in some cases, mechanical ventilation to resolve. The mortality of patients in this phase reaches 50%. An inflammatory condition characteristic of the third phase of COVID-19 is like usual pneumonia, with which radiotherapy has long and successfully coped. Therefore, the use of radiation in this most dangerous phase of acute respiratory syndrome is fully justified. Before the widespread use of antibiotics, pneumonia was considered a dangerous, difficult-to-treat disease. Almost the only remedy was antibacterial sulfamide drugs, the use of which caused severe toxic effects. Therefore, doctors turned their attention to radiation. During the 30 s–40 s of the last century, several articles were published showing the successful fight against pneumonia with the help of low doses of radiation, less than 1 Gy.

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Thus, a group of American doctors led by J.P. Rousseau reported on treating pneumonia with small doses of X-ray radiation in 179 patients. The mortality in this group was 5.7%, and the overall mortality from pneumonia in this hospital was 28%. Some patients came to the clinic in terrible condition; the usual treatment did not help, and they were expected to die by all indications. Shortly after irradiation, the temperature, respiratory rate, and the number of leukocytes returned to normal, and there was an almost complete recovery. Already in August 2020, a letter was published in the journal Dose-Response to the editors of the leading authorities in radiobiology, already cited several times in this book, Jerry Cuttler, Joseph Bevelacqua, and S.M. Javad Mortazavi with the telling title “Unethical not to Investigate Radiotherapy for COVID-19.” After this article, and most likely independently, actual clinical trials of COVID-19 treatment with low doses of radiation began. Many articles describing these works have appeared in severe scientific journals. They provide a biological rationale for the possibility of using radiation to treat COVID-19 and assess the risks of radiation damage and the results of actual exposures. In July 2021, an article by members of the medical department at the University of Louisville in Kentucky appeared, containing a detailed review of the work published to date. Clayton B. Hess and his colleagues at Emory University clinics claim they were the first to use low-dose chest X-rays to treat critically ill patients with COVID-19. The first group of 10 people received a single dose of 1.5 Gy for 10–15  minutes. The dose, generally speaking, is not small. But there were only older adults in the group, in the first five, the average age was 90 years, and one could not think about the long-term consequences. Each of the patients had multiple illnesses unrelated to COVID-19. Nevertheless, in a group of 10 people, 9 people got a sharp and fast, the fastest—in 3 hours, improvement, and disappearance of the main indicators of the disease, one patient died a few days later. In cured patients, no toxic effects of radiation were observed. In the control group, who were treated with conventional methods: oxygen, medicines, and drips, only four out of nine improved. In many other studies, the irradiation regime was, as a rule, the same—a single fraction, but the doses were less, 0.3–1 Gy. Exposure to doses of ~0.1 Gy has also been reported. All articles about COVID-19 radiation treatment use the term low-dose radiation therapy (LDRT). Actually, in the context of radiation protection and many fields of radiobiology, “low dose” is understood to be 100 mGy or less. But radiotherapy is the field of radiation oncology where the daily dose

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fraction is typically 2 Gy, and a total dose may be of the order of 60 Gy, so a single 1.0 Gy is regarded as a low dose. Up to now (information is now available for the end of 2022), several thousand people in serious clinical condition have already received radiation treatment. The results are positive. Each of the radiation-treated groups is too small for reliable statistical inferences. I would like to hope that doctors will not recruit large cohorts, the pandemic will pass, but COVID-19, pneumonia, and other inflammatory conditions will remain. The experience gained in the treatment of COVID-19 will go into the general treasury of information about the treatment with small doses of radiation.

8.11 Radioadaptive Response Closely related to the problem of hormesis is such an interesting phenomenon as the “radioadaptive response”—a phenomenon in which a small adaptive dose of ionizing radiation reduces the damaging effect and increases the resistance of cells or even organisms to the action of subsequent large doses. In principle, both doses, both preliminary and main, actually cause some damage to cells. The effect may be greater than the sum of the two effects, called “synergism.” It may be equal to the sum—this is “additivity” or less than the total effect of two exposures—this is the “adaptive response.” Schematically, the radioadaptive response is shown in Fig. 8.12. The phenomenon was discovered in 1984 by a group of radiobiologists at the University of California G.  Olivieri with co-workers (G.  Olivieri, J. Bodycote, and S. Wolff). They worked with lymphocytes obtained from the peripheral blood of healthy adults and recorded chromosomal aberrations. The radioadaptive response is implemented on many biological objects, from bacteria to mammals. In this case, a wide variety of effects were observed that were suppressed by low-dose adaptive irradiation: DNA damage, Conditioning Challenging dose dose

Response

Time Fig. 8.12  Schematic representation of the concept of radioadaptive response

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chromosomal aberrations, cell death, mutations, and, of particular interest to us, even carcinogenesis. The order of magnitude of the conditioning dose is about 10 mGy, and the main challenging dose, from the dangerous action of which the adapting dose protects, is a few grays. Adaptation was observed in response to both weakly and strongly ionizing radiation. Adaptive radiation can reduce the severity of damaging radiation in different cases in different ways; the most significant known effect is a threefold reduction in the likelihood of tumor formation after challenging radiation. The duration of the adaptive effect is usually hours but can last up to three months. Manifestations of an adaptive response vary significantly for different biological objects; the difference is several times greater for different subjects of the same type. Much evidence for an adaptive response comes from in vitro, i.e., on bacteria, tissue cultures, and animals. Let us give an example of a radioadaptive response in experiments on mice. Thus, for example, lymphoma, commonly induced in mice by 2 Gy gamma irradiation, was significantly suppressed if mice were irradiated with an adaptive low dose of 10 mGy/day for 5 or 10 days before high dose irradiation. In another experiment, the survival of mice irradiated with a low dose of X-ray radiation (0.5 Gy) two weeks before a potentially fatal dose of 7.4 Gy was compared with an unexposed control group. The result is shown in Fig. 8.13. In 30 days after the lethal exposure, more than 90% of previously unirradiated mice died, and only 20% of the irradiated ones.

120 Survival rate, %

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10 15 20 25 Days after second irradiation

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Fig. 8.13  Demonstration of radioadaptive response in mice. Figure on the basis of M.  Yonezawa, A.  Takeda, J.  Misonoh. Acquired radio resistance after low-dose X-irradiation in mice. Journal of Rad. Res. 31, 256, 1990—https://pubmed.ncbi.nlm.nih. gov/2246750/

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The results, called in vivo on a human, actually mean adaptive irradiation of a living person with subsequent exposure to damaging radiation not on the whole person but on their lymphocytes. Since the adaptive response is found in the cells of organisms of all levels of complexity—from bacteria to mammals—it is believed that the adaptive response is inherent in any organism and manifests itself, particularly in relation to carcinogenesis. Thus, the adaptive response is a manifestation of hormesis. It is essential that the adaptive response is a universal response of cells to low-dose irradiation that adaptive irradiation reduces the severity of the consequences not only in the case of subsequent intense irradiation but also for many other non-radiation agents, in particular, in the case of exposure to a chemical carcinogen. Interestingly, under adaptive irradiation, a certain small number of cells are exposed, and then many other, previously not irradiated, cells show a protective effect (adaptive response). Thus, there is a bystander effect here (see Sect. 6.6). Adaptive exposure may be a short-term accidental or intentional event or result from long-term exposure to natural or artificial background radiation. The well-known radiobiologist Javad Murtazavi gives such an example. The frequency of chromosomal aberrations in lymphocytes from exposure to gamma radiation with a dose of 1.5 Sv in residents of the province of Ramsar in Iran, where the background radiation dose rate reaches 260 mSv/year (see Sect. 7.12.4) is significantly less than in residents of areas with a normal radiation background (~3 mSv/year). This shows that long-term exposure to small but noticeably higher than the average background radiation doses induces increased radiation resistance. Both in scientific and popular literature, the problem of radiation during the flight of a person from Earth to Mars and the possibility of staying on Mars are actively discussed. Since Mars has neither a magnetic field nor a dense atmosphere that protects the Earth from cosmic radiation, it is believed that being on Mars is deadly for humans. Curiosity measurements show that the average dose rate on the Martian surface is about 80 mSv/y. The dose rate in open interplanetary space during the Earth-Mars flight is approximately twice as high, i.e., about 150 mSv/y (can reach 380 mSv/year during solar minimum period). But there are populated areas on Earth where the dose rate is even noticeably higher; for example, in the Ramsar region in Iran already mentioned above, it is up to ~260 mSv/y. The population of this region has fully adapted to the increased radiation background. The Internet is discussing the

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possibility of sending Ramsar residents to Mars; for them, there should be no problems associated with radiation. In contrast to this idea, Jawad Mortazavi proposes to test the adaptive response of all potential colonists using conventional cytogenetic tests. Only those who demonstrate a significant adaptive response in these tests should be selected for a flight to Mars. Increased levels of cosmic radiation in the first hours/days will significantly reduce radiation susceptibility and protect colonists from the usual background of Mars and a sudden, unpredictable increase in the background due to solar flares.

8.12 Conclusion The results of a survey of numerous cohorts cited in this chapter that for various reasons were exposed to low doses of radiation show that low doses of all types of radiation are useful for life. Their beneficial effects have been known since ancient times. Already Herodotus and Hippocrates described the healing effect of radon sources. And now, even in one of the most odious cases of mass exposure of the population, experts note that the survivors of the nuclear bombing of Japanese cities outlived their non-irradiated peers. In another, no less odious case, the incidence of cancer in the liquidators of the Chernobyl accident who received a dose less than 100  mGy is noticeably lower than the average for Russia. Reduced cancer risk was also observed in cohorts of workers in the nuclear industry. Those who did not receive excess doses had better health and a lower chance of cancer. A survey of the population living in conditions of increased natural background shows that low doses of radiation protect against lung cancer and do not cause it. Small doses of radiation are also used to treat many diseases. The attitude toward the “dose-effect” relationship and some official bodies is beginning to change. Thus, evidence for the existence of radiation hormesis is presented in a joint report of the French Academy of Sciences and the National Academy of Medicine (Académie des Sciences (Paris) and Académie Nationale de Médecine), which states that the use of the LNT model for risk assessment for doses below 20 mSv is scientifically unjustified and should be canceled. A similar conclusion was made in the report of the UN Scientific Committee on the Effects of Atomic Radiation. The Committee decided not to calculate the absolute number of cancers due to low doses of radiation by extrapolating from data obtained for high doses.

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The attitude of a significant part of the scientific community toward the problem of radiation hormesis is evidenced by the titles of articles and books that are increasingly appearing on the pages of scientific journals and store shelves. American publicist Ed Heiserodt called his book “Underexposed: What if Radiation Is Actually Good for You?” Emeritus professor John Cameron called the 2002 article: “Radiation increased the longevity of British radiologists” and then generalized this result, and in 2005 concluded: “Moderate dose rate ionizing radiation increases longevity.” The founder of the idea of radiation hormesis, Thomas Lucky, has many articles and books on relevant topics; we will give the names of only a few: 1997 “Low dose irradiation reduces cancer death rates.” 2007 “Improved health from Chernobyl.” 2008 “Atomic Bomb Health Benefits.” 2008 “Abundant health from radioactive waste.” Well-known American scientist James Muckerheide in 2000 published a paper: “It’s Time to Tell the Truth About the Health Benefits of Low-Dose Radiation,” and then, in 2004, one more with a similar title: “There has never been a time that the beneficial effects of low-dose ionizing radiation were not known.” The Japanese scientists (M. Mine and colleagues) published a paper titled: “Apparently beneficial effect of low to intermediate doses of A-Bomb radiation on human lifespan.” A Team from John Hopkins University (G.M. Matanoski and colleagues) yet in 1987 asked a question in the paper’s title: “Does Radiation Exposure Produce a Protective Effect Among Radiologists?” This list could be continued, but even from the presented titles, it is evident that many prominent and authoritative scientists accept the idea of hormesis.

9 Radon and Radon Therapy

9.1 Introduction Ionizing radiation accompanied all life on the Earth long before their discovery. The entire history of the emergence and evolution of all living objects, particularly humans, occurred under constant exposure to the natural radiation background, cosmic, and terrestrial origin. Natural background radiation is called radiation that has been formed and is constantly re-formed without human intervention. Radiation background is created by cosmic radiation and by radioactive atoms, called “radionuclides,” contained in the soil, water, air, and any objects surrounding a person, including the human body. For this chapter, it is essential that the radionuclides that create the natural background include natural long-lived radionuclides whose half-life is comparable to the age of the Earth. In scientific literature, such radionuclides are called “primordial.” This group includes, in particular, uranium-238, a heavy radioactive nuclide with a half-life of approximately 4.5 billion years. The peculiarity of this nuclide is that it forms a radioactive chain. The progenitor of the radioactive chain experiences alpha decay, the daughter nuclide is also radioactive and undergoes alpha or beta decay, turning in turn into a radioactive nuclide, etc., until the last daughter (great-, great-, … -granddaughter) nucleus is stable. The decay chain ends with a stable isotope of lead. Approximately in the middle of the decay chain is the same nuclide to which this chapter is devoted, radon. Radon plays a special role in people’s lives, so we devote a separate chapter to it. The special role of radon is worth noting for two reasons. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2023 I. Obodovskiy, From Radio-phobia to Radio-euphoria, Springer Praxis Books, https://doi.org/10.1007/978-3-031-42645-2_9

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The first, well-known, cited in almost all books, articles, and other materials, claims that radon radiation creates about half of the annual dose of natural background. In fact, the real proportion of radon depends on many conditions and, in principle, may even be noticeably more than half. The second one is less often used as an argument, but it seems to be even more important to the author. The second reason is the existence of radon therapy. If the effect of radon really produces a therapeutic effect, if it is not the effect of placebo, suggestion, or mass delusion, if the therapeutic effect of radon therapy is reliably proven, then certain doses of ionizing radiation can be safe and useful. Then this result can be attributed to any kind of irradiation. Radon and its decay products emit mainly strongly ionizing alpha particles, which are especially dangerous since they are noticeably likely to cause double DNA breaks, the repair of which is difficult and little reliable. And if radon therapy has a truly therapeutic effect, then it eliminates doubts about the safety and even usefulness of small doses of other, less dangerous types of radiation. The effect of radon on human health is diverse and contradictory, and to date, there is no complete clarity on this effect. On the one hand, radon is a well-known example of the positive effects of ionizing radiation. Historians of science argue that radon-containing sources were used for health purposes even in ancient Rome, medieval Japan, and Central Europe. Balneological spas (Baden-Baden, etc.), based on natural sources of radon waters, were popular long before the discovery of radioactivity and continue to attract people up to the present time. On the other hand, the role of radon as the leading cause of lung cancer, for example, of uranium miners, is beyond doubt. The damaging and therapeutic effects of radon manifested itself long before the discovery of radon and radioactivity in general. Because of radon, miners of mines in the center of Europe in Schneeberg and Joachimsthal in the XVI century were seriously ill and died rapidly. This is described in more detail in Sect. 4.1. The role of radon in the development of lung cancer in uranium miners was finally recognized only in the 1970s. Naturally, the question arises, where is the border between radon’s beneficial and harmful effects? There is much uncertainty in the dependence of radiation effect on the dose. In different works, directly opposite results are given, and studies and discussions are continuously struggling. We will try to highlight the modern state of this problem. Radon in the atmosphere around us, outdoors or indoors, is always there, regardless of desire and lifestyle. Some radioactive nuclides such as tritium, carbon-14, and others can enter the body naturally, but their concentration is

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minimal, and their role in irradiation is highly insignificant. Other nuclides can enter the body in appreciable concentrations only in exceptional cases— in accidents, when working in contaminated areas, and intentionally, under controlled conditions during radiological procedures. But radon is always there, and its role in creating the radiation background is significant. As mentioned, it determines more than half of the annual radiation dose to a person. The peculiarity of its effect is that, unlike most other sources of background, it creates internal irradiation. In the readings of street and household dosimeters, the dose created by radon is not included. If the external background, as shown by the Moscow street dosimeter in Conclusion in Fig. 12.4, is 0.15 μSv/h, then the total background, considering radon, is about twice as large.

9.2 Radon and Its Role in Radio-euphoria The significance of the discovery of radioactivity reached the general public more slowly than in the case of Röntgen’s discovery. But the discovery of radium had already sparked massive enthusiasm. A substance glowing in the dark, emitting invisible rays and emanations, very quickly began to be considered a panacea and almost a source of life. The discovery of a gaseous decay product of radium, originally called the emanation of radium and then called “radon,” played a unique role in the popularity of radioactivity in the world and the spread of the state of radio-euphoria. By the time radioactivity became known, the healing capabilities of many mineral springs had long been beyond doubt. The healing waters of Austrian and German resorts were well known; in the United States, the most famous healing waters were discovered in the state of Arkansas, in the area of Hot Springs. Back in 1832, Congress established a special federal zone here, the predecessor of future national parks. In 1903, the English physicist who discovered the electron, the future Nobel laureate (1906) J.J. Thomson, discovered the presence of radioactivity in well water, and then, by the work of other scientists, it was shown that this radioactivity was determined by radon. The specialists had no doubts that it is radon that makes the water of mineral springs curative. And from here, major medical authorities concluded that radon is so crucial for water that it can be considered its vital element. “Without radon, water is dead. Radon is to water what oxygen is to air.”

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Since radon is so useful, it is necessary to give people the opportunity not only to go to radon sources but also to supply them with water saturated with radon at home. But radon has a short half-life (T1/2 = 3.8 d); such water cannot be stored for long. Therefore, manufacturers began to produce special vessels containing radium, which emanate radon and saturate the water with it. In addition to bottles containing radium water, special vessels containing radium were produced, which had to be filled with pure water to allow radon to accumulate and saturate. For example, the vessel “Revigator,” made of radium-containing ceramics is shown in Fig. 9.1. Several hundred thousand such vessels were sold, despite the relatively high cost ($ 29.50 in 1929). There were other devices in use, such as a room emanator or a radium emanator, that were placed in water rather than water poured into them. They were noticeably smaller than the Revigator so they could be taken with you on the road. The situation in Russia is characterized by advertising the well-known “radioactive water Borjomi” (Fig. 9.2). Many mineral waters contain radon.

Fig. 9.1  A can for saturating water with radon (Radium Water Jar 1920–1930), measuring 8 × 8 inches (20 × 20 cm). Figure from the collection of the Oak Ridge Museum of Radiation and Radioactivity—https://www.orau.org/health-­physics-­museum/collection/radioactive-­quack-­cures/jars/radium-­water-­jar-­1920s-­1930s.html. With the kind permission of Dr. Pam Bonee

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Fig. 9.2  Advertising of “radioactive water Borjomi (Боржом).” The text on the label is in Russian

Still, it has a relatively short half-life, and by the time water goes on sale, it practically does not remain in the water. When bottled water degassing occurred, radon disintegrated already in the air, and the products of its decay also left the water. The activity of the water sold was very weak, if at all. The cited Borjomi leaflet was issued in the 1920s. Another example of the use of reference to radioactivity as a property that increases the product’s attractiveness is Izhevsk mineral water. In the second half of the XIX century, Izhevsk mineral water was used by local doctors to treat several diseases, primarily the gastrointestinal tract. Shown in Fig. 9.3, the label from the bottle of mineral water, “Izhevsk Source” was issued after the Second World War. From the label, it could be seen that the enterprise is part of the Ministry of Food Industry system. As you know, in the USSR, government departments received the name of the Ministry only in 1946; before that, they were called People’s Commissariats. The Ministry of Food Industry was formed at the end of September 1953, after the death of Stalin and the total reorganization of the government departments by his successor Nikita Khrushchev. It means that the label was issued no earlier than the autumn of 1953, after Hiroshima and Nagasaki, after the events with the Japanese fishing vessel Fukuru-Maru, and after some tragic

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Fig. 9.3  Label from the bottle with mineral water “Izhevsk Source.” Text on the label is in Russian

radiation events. Nevertheless, the possible content of radioactive substances, mainly radon, in this water is emphasized for advertising purposes.

9.3 Radon Properties Radon played a considerable role in creating the atmosphere of radio-­euphoria. Gas, which has no color, taste, or smell, has captured the attention of millions of people. “Radon” is the general name of the element. Three of its isotopes have their own names: thorium emanation—thoron (Rn-220), discovered by R. Owens and E. Rutherford in 1899, radium emanation—radon itself (Rn-222), discovered by F. Dorn and A. Debjern in 1900, and actinium emanation—actinon (Rn-219), discovered by A. Debjern and F. Gisel in 1902. All radon isotopes occur in nature, entering the natural radioactive series, two of them play a certain role in the radiation background: thoron from the thorium chain and radon from the uranium one. Thoron has a relatively short half-life of 55.6 s; its radiation is taken into account only with a thorough analysis of doses. In indicative estimates, its role can be neglected. The primary role is played by radon (Rn-222), its half-life is 3.82 days = 3 days 20 hours 16 minutes. Note that in the entire periodic system of the elements, just yet isotopes of hydrogen, deuterium, and tritium have proper names. Radon, element number 86 in the periodic table, occurs during the alpha decay of radium-226 and in turn, undergoes alpha decay. The chain of decay of radon is part of the chain of decay of uranium-238 (Fig. 3.5). The elements

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in the chain next after radon can undergo both beta and alpha decay. Of these, we distinguish two alpha decays: polonium-218 and polonium-214, the first half-life is 3 minutes, and the second—is fractions of a second. The last of them turns into lead-210, which has a half-life of 22.3 years, and on it the decay chain is delayed for a period significantly longer than the duration of the processes of influence of radon decay products on human health. So, the last radioactive nuclide in the decay chain, which has recently become famous, the alpha-active nuclide polonium-210, practically does not take part in the effects on humans. Radon is one of the family members of inert, otherwise called noble gases. This means that radon practically does not enter into chemical bonds. Inhaled radon is little retained in the lungs, and a significant part of it is excreted during exhalation. Some radon diffuses through the epithelium into the bloodstream and spreads throughout the body. It is believed that radon itself gives in irradiation at most 1–2%. The main effect on the body is created by the radon decay products emitting alpha particles; these are polonium-218 and polonium-214. For a long time, radon was the last, heaviest inert gas. But recently, an element was synthesized that completes the seventh period of the periodic table and, accordingly, a column of inert gases. This is an element with atomic number 118, named “oganesson” in honor of academician Yuri Tsolakovich Oganessian, head of the Laboratory of Nuclear Reactions of the Joint Institute for Nuclear Research (JINR) in Dubna, Russia, which played an essential role in the synthesis of many transuranium elements. This is the second element named after the living scientist. The first was element No. 106 “seaborgium,” it was given the name of the famous American scientist, Nobel laureate in chemistry (1951) Glen Seaborg, under whose leadership ten transuranium elements were synthesized, starting with the main element of nuclear weapons, plutonium. Seaborg died in 1999, so now Y.T. Oganessian is the only living scientist after whom the chemical element is named. So far, only a few oganesson atoms have been obtained. Still, they have given the right to the International Union of Pure and Applied Chemistry (IUPAC) to approve this element’s production and its name officially. But back to radon.

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9.4 Radon Concentration in Atmosphere The most important natural source of radon is the breakdown of radium-226 in soil and rocks. As a result, radon atoms fall into the crystalline solution of minerals and may end up in cracks or pores. Through the cracks, radon atoms leave the thickness of substances and enter groundwater or the atmosphere. Two terms are used to describe the release of radioactive gases from rocks. The radon separation from minerals and rocks into cracks is “emanation.” Releasing all gases from vast geological structures is called “exhalation.” Thus, radon emanates from minerals and then exhales into the air. Planet Earth continuously exhales a huge amount of radon, ~ 90 Exabecquerels (EBq) annually. It is the source of a never-ending supply of radon gas. The decimal prefix “Exa” means 1018, i.e., a unit with eighteen zeros. And this is only the release of radon from the land’s surface. Estimates show that a vast amount of radon, comparable to what land emits, comes out of the leaves of green plants. And a hundredth of what the land emits walks from the ocean’s surface. But radon yield is not uniform. Radon yield maps are currently being published. The Environmental Protection Agency map of radon concentrations in US homes is shown in Fig. 9.4. The analogous map of Europe is presented in Fig. 9.5.

Fig. 9.4  EPA map of radon concentrations in the US homes by State. The concentration of Radon is indicated by three colors: yellow—less than 74 Bq/m3 (2 pCi/l); orange— between 74 and 148 Bq/m3 (2–4 pCi/l); and red—more than 148 Bq/m3 (4 pCi/l). Figure from the site of Environmental Protection Agency, Ecohome—https://www.ecohome. net/guides/3520/radon-­g as-­l evels-­b y-­s tate-­p rovince-­m ap-­t est-­h omes-­b asements-­ crawlspace/ Public domain

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European indoor Radon map, December 2011

2 500

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100 to < 300 300 to < 1 000 1 000 to < 10 120 No data

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Arithmetric means (AM) of indoor radon concentrations in ground floor rooms, 10 x 10 km grid cells.

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Becquerel (Bq) is the lnternatiolnal System of Units for radioactivity. Source: European Commission, DG Joint Research Centre (JRC), Institute for Transuranium Elements, REM Action

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Fig. 9.5  The map shows the indoor radon concentration in Europe averaged over 10x10 km grid cells. Figure from European Environment Agency (EEA). Joint Research Centre (JRC). Radioactivity Environmental Monitoring—https://www.eea.europa.eu/ data-­and-­maps/figures/european-­indoor-­radon-­map-­december-­2011. Copyright holder: Joint Research Centre (JRC)

Since radon is a decay product of radium and radium—of uranium, its release is affected by uranium concentration in the soil and rocks. But this is not the only parameter that determines the concentration of radon; the yield of radon depends on the porosity and permeability of rocks, on the position of the groundwater level, and on the ability of radon to escape from the rock. Weakly radioactive rocks may contain radon in their voids and cracks in quantities hundreds and thousands of times greater than more radioactive ones. Groundwater flows carry a significant part of the radon into the environment. In such areas, a balneological resort is created at the outlets of radioactive waters. The concentration of radon depends not only on its yield but also on meteorological conditions. The radon concentration drops markedly when the microcracks through which radon comes from the soil are filled with water.

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The snow cover also prevents radon from entering the air. Therefore, in areas covered in certain seasons with snow and ice, seasonal changes in radon concentration also occur. At night and early in the morning, radon stays closer to the earth’s surface; radon rises during the day when the sun heats. During the day, the radon concentration can vary by about ten times. The total content of radon in the atmosphere decreases freely sharply with altitude. A connection between the radon concentration in the air and seismic activity was found, which suggests the possibility of using radon as a harbinger of earthquakes. The radon concentration in air is measured in units of activity in a unit of volume—Bq/m3 (becquerels in cubic meter), i.e., in the number of decays per second in 1 m3 of air. The average volume concentration of radon at the level of the earth’s surface in the air of continental regions is ~10 Bq/m3, in coastal areas ~0.4 Bq/m3, on islands, over the ocean and in the Arctic regions ~0.02 Bq/m3.

9.5 Radon Concentration in Mines Since radon comes out of the ground naturally, the highest concentrations are observed in mines, in principle, in extracting any minerals. Most of all in the world are coal mines. However, the role of radon in coal mines is relatively small. There could be quite a lot of it. Still, because of the danger of accumulation of explosive methane, there is usually good ventilation in such mines, significantly reducing the radon concentration. A typical radon concentration in coal mines is about 1000–3000 Bq/m3. In mines where other minerals are mined, radon concentrations are usually higher, although there may be peculiarities. For example, the gold mines of South Africa employ about 250,000 miners. They have an average depth of 1600 m and the deepest—3500 m. At such depths, temperatures are very significant, and creating acceptable working conditions requires active cooling and ventilation of air, which also significantly reduces the concentration of radon and its decay products. Most of the radon is in uranium mines since it is uranium that is the ancestor of the decay chain in which radon is formed. In the middle of the XX century, in uranium mines, the radon concentration was hundreds of thousands and millions of Bq/m3. Studies have shown that radon is the main cause of miners’ cancer. Serious measures have been taken to ventilate mines, which has reduced the radon concentration by a factor of thousands. In addition, there is a shift in effort from underground uranium mining to open-pit

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mining in quarries or by underground leaching. All this made it possible to reduce the incidence of miners significantly.

9.6 Indoor Radon Concentration The association of radon with lung cancer in miners, and in general, the gradual understanding of the significant role of radon in the environment, stimulated the study of radon content in residential premises. It turned out that although, as a rule, the concentration of radon in houses is noticeably less than in mines, nevertheless, in some cases, an effective content of radon can accumulate in the premises. Its concentration depends on the type of dwelling, the ventilation conditions, the permeability of the building foundation material, the pressure of the foundation on the soil, the floor material, and the gap between the floor and the walls. Estimates show that the concentration of radon in the room’s air is mainly determined by penetration from the material of the building and convection from the basement. Only 20% of radon comes from the street. Note that the spread of concentrations in different rooms is very significant. Another source of radon in the home is water from the water supply system when used, especially if the water is obtained from nearby underground sources. Possible ways of radon entering a two-story building are shown in Fig. 9.6. Another source of radon in the room is the use of household gas. Numerous measurements in many countries on all continents give an average of indoor radon concentrations under typical conditions of the order of 30–40 Bq/m3. To illustrate the effect on the concentration of specific conditions, here is an example. In the premises of the Brussels Museum, where uranium-­ containing minerals from Katanga are exhibited, the radon concentration is approximately 10–15 kBq/m3, despite increased ventilation. This is several hundred times more than in standard rooms. Due to radon and gamma radiation of minerals in the house of the museum caretaker living nearby, the absorbed dose was estimated at 5–6 μSv/h (~45–50 mSv/year). Shielding of minerals allowed to reduce this dose by about 5 times. In the United States and Europe, intensive studies are being conducted to determine radon concentration in dwellings. It is assumed that such studies will cover every home. International and national standards standardize permissible concentrations of radon in indoor air. In 1996, the World Health Organization (WHO) proposed setting the maximum radon activity in

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Fig. 9.6  Illustration of the sources of radon entering the home. 1—cracks in concrete slabs; 2—spaces behind brick veneer walls that rest on hollow—block foundation; 3— pores and cracks in concrete blocks; 4—floor–wall joints; 5—exposed soil, as in a sump; 6—weeping (drain) tile, if drained to open sump; 7—mortar joints; 8—building materials, such as some rock; 9—water (from some wells). On the basis of Masters G.M.  Introduction to Environmental Engineering and Science. Englewood Cliffs, NJ: Prentice Hall International, Inc. (1991)

homes at 1000 Bq/m3. However, in 2009, the new value of the maximum permissible concentration of radon (MPC), on which the WHO insists, was reduced to 100 Bq/m3. The same norm is established by the Standards and Radiation Safety (NRB-99) currently in force in Russia—100 Bq/m3 (for buildings built after 1999) and 200 Bq/m3 (for previously constructed buildings). In cases where it is impossible to maintain such limits, WHO advises limiting itself to a value of 300 Bq/m3. Instructions recommend that measures are taken to reduce this background in homes with high concentrations. Reducing the radon concentration to the indicated values is expensive and, as we see below, useless and perhaps even harmful. Also note that in the building, the radon concentration can be greater than outside it, and the difference can reach ten times due to the pressure difference between the room and the atmosphere. This difference is estimated at about

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5 Pa and is due to two reasons: the wind load on the building and the temperature difference between room air and the atmosphere. It is established that the nature of variations in the radon concentration in the room depends on the season. In summer, the volume activity of radon in low-rise buildings is subject to substantial daily fluctuations, which are characterized by highs at night and minimums during the day. The radon concentration is directly proportional to the temperature difference inside and outside the room and is inversely proportional to the wind speed. In winter, the concentration of radon indoors is usually, on average, three times higher than in summer and changes inversely in proportion to the temperature difference inside and outside the room, and daily fluctuations are almost imperceptible. And the change in the concentration of radon indoors during the day can be caused by water from closely located underground sources. It is from the water that significant radon concentrations enter the room, as shown in the graph in Fig. 9.7. They can, but do not necessarily do. In the water supply systems of large cities, radon, as a rule, goes away in water treatment, but in small towns, cottages, and country cottages, water can be an essential source of radon. 5000

3000

1000 0

Shower off

2000 Shower on

Radon concentration, Bq/m3

4000

10

20 Time, min

30

Fig. 9.7  Change of radon concentration in the shower (in the bathroom)

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The role of ventilation is illustrated in Fig. 9.8. Radon concentration drops rapidly and significantly when opening a window and slowly increases after closing.

9.7 Radon in Multistory and High-Rise Buildings

Radon concentration, Bq/m3

Since the soil under the building is considered the main radon source, the radon content was initially measured in basements and one-story buildings. However, recent studies in multistory and high-rise buildings have shown that radon can be transported efficiently through stairwells and elevator shafts to the upper floors. A particularly difficult situation develops in houses where to save energy, they reduce or even stop the exchange of room air with atmospheric air, thereby contributing to the accumulation of radon up to significant concentrations. In ordinary buildings, measurements show a variety of dependencies of radon concentration on floor number, but, apparently, more or less universal is the situation when the maximum concentration of radon is fixed in the basement, and on the first and subsequent floors the concentrations are somewhat less and differ little from each other. In a series of works, a group of Russian researchers (A. Vasiliev et al.) measured the radon concentration in multistory buildings, particularly in 16 and 25-story buildings on different floors in several Russian cities. It was found that the radon concentration is determined mainly by the rate of entry from the walls and from the street, typical values of 30–60 Bq/m3 hour, and the rate of air exchange in the ventilation system. It turned out that, for example, on

300 250

Window closing

200 150 100 50 0 0

5

10 Time, hours

15

20

Fig. 9.8  Change in the concentration of radon in the room when opening the window at the time of 0 and closing after 1 hour. An arrow shows the moment of closing

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the 15th floor of a 25-story building, the concentration was 368 Bq/m3, and on the 1st floor of a 16-story building—133 Bq/m3. So, radon accumulates not only in basements and first floors.

9.8 Radon in Underground Areas Radon is not only in mines and dwellings. Since radon comes from underground, we expect noticeable radon concentrations in any underground structures: at metro stations, in tunnels, underground shopping centers, parking lots and warehouses, in caves, etc. After realizing the danger of large doses of radon, gradual measurements of radon concentrations in various underground rooms have begun. The concentration was significant in caves and mines open to tourists—up to 20 thousand Bq/m3. Usually, tourists are not in such premises for long, so it is not dangerous for them, but it can be a severe problem for the staff. In underground shops, parking lots, at metro stations, the concentration of radon, as a rule, is relatively small; for example, the average concentration value at metro stations in Prague was ~12.5 Bq/m3. This is understandable; ventilation is one of the most effective ways to reduce radon concentration. However, in 1998, on one of the Seoul subway lines at nine stations, the concentration reached ~1200 Bq/m3. But measurements were taken, and it is known that as soon as the concentration is brought to a reasonable level, such exceedances are easily eliminated.

9.9 On the Relationship of Dose Rate with Radon Concentration Measuring radon concentration in the air is quite an obvious and reliably solvable task. There is a set of quite effective devices of different types, which, depending on the measuring conditions and the range of concentrations, allow you to obtain concentration values and their changes over time. When radon concentrations are determined, two problems need to be solved in principle to analyze the health effects of radon exposure. First, it is necessary to associate the dose received with the radon concentration. Second, it is necessary to associate the radiation effect with the dose received, i.e., harm or benefit of radiation exposure. In other words, it is necessary to obtain a dose–effect dependence.

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Radon decays, usually in the atmosphere, and its decay products are metal atoms that actively interact with environmental molecules. In the outer air, the new atoms that arise during radon decay quickly stick to existing aerosols. In the lungs, they settle in the respiratory tract and can undergo alpha decay before the lungs are cleared of inhaled dust and aerosols naturally. The alpha particles that arise during decay produce the main effects on cells. The peculiarity of determining the doses created during breathing with air containing radon is that a dosimeter cannot be inserted into the trachea or, more precisely, into some critical epithelial cells on the surface of the respiratory tract. Therefore, doses have to be calculated by formulating specific models. The relationship of real doses with the concentration of radon in the air is determined by many factors; a vital role is played by the filtration of aerosols in the respiratory tract, the determining of the distribution of aerosols by size, their structures, and properties. It must be considered respiratory rates, the volume of inhalation, the amount of air inhaled through the nose and the mouth, the state of the respiratory tract, the time during which the decay products of radon remain in the body, and their half-life, the depths at the location of target cells in the tissue, the possible presence of mucus on the surface of the epithelium of the trachea and bronchi. Since many of these features differ for different people, men and women, mines, and the population, the coefficients linking radon concentration and dose will differ; this relationship needs to be clarified. Epidemiological data link the dose rate to its radon concentration for various standard exposure conditions in homes and workplaces. Taking into account the latest and most accurate data on various physical and biological parameters and reasonable dosimetric means, it is assumed that both indoors and outdoors, the concentration of radon 1 Bq/m3 creates an effective dose rate in the range of 5–25 nSv/h. For evaluations, one could take the average rounded value of ~10 nSv/h ~ 90 μSv/year at 1 Bq/m3. With an average outdoor radon concentration of ~10 Bq/m3, the average dose rate is ~0.1 μSv/h ~ 0.9 mSv/year. Indoors, the dose rate can be several times greater. Some radon decay products emit gamma quanta, which have significant penetrating power and irradiate the entire body. Disambiguation shows that the dose to the whole body is approximately 0.12 of the dose to the lung.

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9.10 About the Cleaning System of the Lungs There is another problem in determining the dose–effect relationship. In humans and, apparently, other mammals, there is a purification system from the aerosols that fall into the lungs. Professor Brian Button of the University of North Carolina has long been investigating a lung cleaning system that consists of a layer of mucus on the surface of the bronchi that traps inhaled aerosols and a layer of particular cilia that can transport mucus from the lungs. The cilia oscillate with a frequency of about 1000 vibrations per minute, working as a transporter, removing mucus from the epithelial surface of the bronchi. Next, this mucus is spitting or swallowing. A group of Norwegian researchers from the University of Oslo (UiO), Department of Physics, Biophysics and Medical Physics (BMF-group), has attempted to calculate the rate of spontaneous purification of lungs. They estimate that a significant portion of the dust with adhered atoms of radon decay products is removed from the lungs in a time comparable to the half-life of these products. There are quite a few factors that cannot be taken into account at present. Age, smoking intensity, possible diseases such as asthma or bronchitis, the air environment’s general state, and a person’s characteristics play a role. Therefore, Norwegian researchers make a categorical conclusion: the dose from inhaled radon cannot be determined. The critical role of spontaneous purification of lungs drew attention recently, and the author is unaware of works in which, when determining the dose of radon, the effectiveness of spontaneous purification of radon would be considered. But, generally speaking, it could be more important. You can do it without knowing the dose or rather, the dose rate. Since the concentration of radon in the inhaled air is known, it can be compared with the biological effect, i.e., when analyzing the dose–effect relationships, the concentration–effect relationship will immediately be obtained. Thus, it is the concentration of radon that turns out to be the most representative parameter characterizing the effect of radon on health, much more specific than the dose.

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9.11 The Biological Effect of Radon The effect of radon on the body may differ from the effects of other sources of exposure to the natural background. In the case of radon, strongly ionizing alpha particles emitted by radon decay products produce exposure. Alpha particles have a low range, on the order of tens of microns in biological tissue and affect mainly the cells of the epithelium of the trachea and bronchi. Almost all other sources of natural background radiation emit weakly ionizing particles—electrons. Now we know that even in ancient times and in the Middle Ages, people were treated with radon and suffered from radon, although the existence of radon was not suspected. Suspicions that radon was responsible for cancer in the miners appeared in the 20 s–30 s of the last century. Gradually, for almost half a century, information about the relationship of radon with the diseases of the miners accumulated. There was an understanding that it was not radon itself, but its decay products that created the main effect on the respiratory tract of the lungs. The scale of the danger of radon to mines is indicated by such numbers in the report of the US Academy of Sciences Committee on the Biological Effects of Ionizing Radiation (BEIR VI, 1999). In epidemiological studies of 11 groups of miners of various mines with a total number of ~60 thousand people, cancer was diagnosed in ~2600 miners. However, based on the average distribution in the United States, only 750 of the disease could be expected. That radon is present not only in mines but also in residential premises, it turned out even in the 1950s. And then, by about the 1970s, there was a perception that radon could threaten not only the miners but also the population living in ordinary buildings. Simply extrapolating data from miners to estimates of lung cancer risk in the population is very difficult. A large number of factors have to be taken into account when extrapolating from conditions in mines to conditions in dwellings. Among these factors is ambiguity with the law by which such extrapolation can be carried out, i.e., doubts about linearity. Dose–effect relationships, differences in risk for adult men (miners), and populations including women and children, differences in other possible exposures to environmental pollution, such as dust, engine exhaust, smoking, and more. In addition, the miners work in the mines for several years for several hours a day, and the population in the premises is exposed to radon almost around the clock throughout life.

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Therefore, quite intensive epidemiological studies of the effect of radon on public health have begun. The results of the research were contradictory. Much of the work, that used a linear no-threshold model to process the results, concludes that radon is hazardous even at very low concentrations. On this basis, the International Agency for Research on Cancer classified radon as a human carcinogen. Using this model, the U.S. Environmental Protection Agency (EPA) calculated that each year approximately 21,000 Americans die from radon-induced cancer. This claim is cited in many articles. In 1988, the U.S. Congress passed, and President Ronald Reagan signed the Indoor Radon Abatement Act. The law recommended that all (!!!) buildings be inspected and that the indoor concentration of radon is close to that of the surrounding space. In numerous recommendations, EPA experts claim that there is no safe radon concentration. The boundary below which it is pointlessly to reduce the radon concentration is the value of 2 pCi/l of air. This corresponds to 74 Bq/m3. In this matter, as in many others, Americans remember inches, miles, pounds, and gallons, using off-system units. It is recommended to carry out work to reduce the radon level if the concentration exceeds the limit value of 4 pCi/l (148 Bq/m3). The concentration range of 74–148 Bq/m3 (2–4 pCi/l) is considered a gray zone. Particular attention was paid to the radon content in schools. Similar programs exist in European countries, including Russia. In Russia, the boundary value called the “reference level,” is 200 Bq/m3. It should be noted that to implement the requirements of this law, the US government has allocated significant funds, tens of millions of dollars, and a solid bureaucratic group has been formed that distributes these funds and controls their use. The average cost of measures to reduce the radon concentration in one house is estimated to be a thousand dollars but can reach 3 thousand in difficult cases. However, studies of miners’ morbidity and mortality showed that up to radon concentrations of ~1000 Bq/m3, creating a dose rate of ~180 mSv/year for lungs and ~20 mSv/year for the whole body, there was no increase in the incidence of lungs cancer among miners compared to a control group that was in an atmosphere with radon concentrations of less than 50 Bq/m3. In other studies, an even stronger restriction was obtained: no undesirable effects were observed up to 2100 Bq/m3. So, the high costs of reducing the radon concentration at the level of several hundred Bq/m3 seem doubtful at today’s level of knowledge. To date (fall 2021), a large number of epidemiological studies of the effects of indoor radon on health have been performed. Many find certain harm to health, even from small concentrations of radon. But there are a growing

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number of studies showing that the use of the linear non-threshold model distorts the real picture of the effects of radon on health. Since the beginning of the 1990s, the American scientist Bernard Cohen has conducted extensive environmental studies of the effect of radon in residential premises on the mortality of residents of 1729 counties in the United States from lung cancer. The studies covered a significant portion of the U.S. population (89 percent, or about 200 million). The dose dependence obtained by the author is shown in Fig. 9.9. Studies show decreased cancer mortality in U.S. counties with increased radon concentrations in dwellings in the radon concentration range up to ~220 Bq/m3. This is what is called radiation hormesis (see Chap. 8). Cohen has conducted a so-called ecological version of an epidemiological study that compares the average mortality rate in a county with the average concentration of radon in that county’s premises, which differs from conventional epidemiological studies, where an individual’s risk of death is compared to the dose they receive.

1.4

Lung cancer mortality, rel. units

Linear no-threshold model

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Radon concentration, Bq/m3

Fig. 9.9  The dependence of lung cancer mortality in the U.S. population on the concentration of radon indoors. Figure on the basis of B.L. Cohen. Problems in the Radon vs. Lung Cancer Test of the Linear No-Threshold Theory and a Procedure for Resolving Them. Health Physics. 72, 623–628, 1997—https://pubmed.ncbi.nlm.nih.gov/9119688/

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Initially, Cohen’s results were met with strong objections. Some official organizations did not consider Cohen’s results, as if these studies did not exist at all. The International Agency for Cancer Research of the World Health Organization published a demand not to consider the results of Cohen’s analysis. However, over time, more works confirm Cohen’s results. And in an article by the well-known American researcher Bobby Scott, even the title of the article of 2011 states: “Residential radon appears to prevent lung cancer.” A relatively recent investigation published in 2019 confirmed this result: “At low indoor radon exposure levels, reverse (negative) correlation between radon exposure level and lung mortality predominate.” Another example of a concentration relationship is the effect obtained in Worcester County, Massachusetts, in Fig. 9.10. It can be seen that at low concentrations, radon has a protective effect and becomes dangerous at approximately the same concentrations as in Cohen’s work. There are more and more articles in the press justifiably criticizing works showing the dangers of small doses of radon. For example, an article by well-­ known specialists B. Sachs, G. Meyerson, and J. Siegel from the Food and Drug Administration (FDA) in the title has the following words: “Epidemiology without biology: false paradigms, unfounded assumptions, and specious statistics in radiation science.” Here are some statements from this article:

Lung cancer risk

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0.1

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Radon concentration, Bq/m3

Fig. 9.10  Risk of lung cancer as a function of radon concentration in residential premises of Rochester County, Massachusetts. Figure on the basis of Thompson R.E., Nelson D.F., Popkin J.H., Popkin Z. Case-control study of lung cancer risk from residential radon exposure in Worcester County, Massachusetts. Health Physics. 94, 228–241, 2008— https://pubmed.ncbi.nlm.nih.gov/18301096/

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• “Radiation science is dominated by a paradigm based on an assumption that has no empirical basis.” • “Epidemiological studies that claim to confirm LNT (linear non-threshold model) either neglect experimental and/or observational discoveries at the cellular, tissue, and organismal level or mention them only to distort or dismiss them. The appearance of validity in these studies rests on circular reasoning, cherry picking, faulty experimental design, and/or misleading inferences from weak statistical evidence.” A large group of specialists, biologists, oncologists, and biophysicists, including such authorities as, for example, Professor Ludwig Feinendegen, published in 2015 a letter in the journal “Cancer Causes & Control,” which says: “… excess risk of lung cancer due to low concentrations of radon has been neither empirically detected nor theoretically demonstrated, while the opposite has, in fact, been supported by voluminous evidence. The putative increase in lung cancer risk due to low radon concentrations is not a real effect; it is an assumption only.” Many authors pay attention to the fact that the authors of the works in which the linear model is substantiated fall into a vicious circle. The results confirm the hypothesis adopted when processing the results. The linear non-threshold model does not assume the existence of negative effect values, precisely what is observed in the case of hormesis. As a rule, it is not considered impossible to form a control group with zero irradiation. On planet Earth, zero concentration of radon does not occur. It is noted that many authors of articles that supposedly confirm the linear model do not even discuss alternative options. It is necessary to give several more arguments in favor of a low danger of low concentrations of radon. For example, the U.S. Commission on the Biological Effects of Ionizing Radiation in 1999 provides a graph of cancer mortality in the United States from 1930 to 1986 (Fig. 9.11). During this period, mortality increased by 14 times. But the concentration of radon in homes during this time most likely did not change; the main reason for the increase is the prevalence of smoking. So, the authors conclude that this indicates a minor role of radon in the occurrence of lung cancer. Considering the changes in diagnosis and treatment over this half-century does not fundamentally change the main conclusion. A similar finding has been received from the analysis of cancer among virtually non-smoking residents of Utah and Mormons. Several early studies in the United States have found lung cancer is much more common in white miners than among Native American Indians.

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Lung cancer mortality

80 Men

60 40 20 0 1920

Women 1940

1960

1980

Time, years

Fig. 9.11  Deaths from lung cancer (per 100,000 people) of men and women in the United States in the period 1930–1985. Figure on the basis of BEIR VI 1999, p. 232

Initially, there were suggestions about ethnic or racial differences in susceptibility to cancer. But further observations of the miners showed that there are much fewer Indian smokers, which determines the difference in the likelihood of the disease. So, in our descriptions of the effects of radon on health, another factor appeared—smoking. It is necessary to discuss the relationship between radon, smoking, and cancer in more detail. It should be noted that smoking is a much more potent carcinogen than radon, at least at the concentrations that the population must encounter in nature and homes.

9.12 The Role of Smoking Smoking is an additional and essential factor that must be considered when analyzing radon’s effects on health. Some other factors may also play a role. In principle, these factors can add up. This situation is called “additivity.” But in some cases, individual factors can strengthen or weaken the actions of another. If the effect of the interaction of two or more factors significantly exceeds the simple sum of the effect of each component, then this phenomenon is called “synergy.” In other cases, one of the factors can weaken the action of the other. This phenomenon is called “antagonism.” In the case of the interaction of radon and smoking, both cases are realized—synergy and antagonism. Some published epidemiological researchers show strong synergies between radon and smoking. The risk of cancer in smokers increases with increased radon concentrations is noticeably faster than in non-smokers. This situation can be illustrated by the results of the

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analysis of 13 studies in various European countries by a large group of scientists of different profiles under the leadership of Professor Sarah Darby of the University of Oxford. The graph we built based on this analysis is shown in Fig. 9.12. It can be seen that the mortality rate from cancer among smokers increases sharply with an increase in the concentration of radon. At the same time, mortality among non-smokers on the scale of this graph is practically not noticeable. Moreover, according to the authors, the observed slight increase in cancer mortality among non-smokers is very likely determined by the so-called secondary smoking, i.e., inhalation of tobacco smoke by smokers. I quote the article’s authors: “Without smoking, the effect seems to be so small as to be insignificant.” In other studies, the opposite picture is observed. Thus, in a work carried out under the direction of Dr. Jay Lubin from the U.S. National Cancer Institute, the cancer mortality of miners in various mines was investigated. The study claims that the danger of radon for non-­ smokers is about three times greater than for smokers. Differences in the results of different authors may depend on the degree of dust and the nature of the dust. If dust can be a radon sorbent, this is one thing; if not, then another. It is also important to determine how long this dust particle can persist in reticuloendothelium cells. As a well-known specialist in the problems of carcinogenesis Professor Gennadiy Belitsky reported in a private letter to the author, “At one time, it 25 Lung cancer mortality, %

Smokers 20 15 10 5 0

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Fig. 9.12  Dependence of lung cancer mortality among smokers and non-smokers on radon concentrations in homes in the United States. Figure on the basis of Darby S., Hill D., Auvinen A., et al.. Radon in homes and risk of lung cancer: collaborative analysis of individual data from 13 European case-control studies. BMJ, 330, 223–6, 2004—https:// pubmed.ncbi.nlm.nih.gov/15613366/

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was not possible to obtain lung cancer in the experiment by directly introducing the classical chemical carcinogen benzpyrene into the lungs of rats, and it was possible only after the carcinogen was loaded into finely dispersed soot, which is firmly held in the cells of the connective tissue of the respiratory tract.” Perhaps in miners, the combined effect of industrial dust and tobacco creates a layer on the surface of the respiratory tract that inhibits alpha particles and reduces the energy transmitted to the tissues. The type of normal and inflamed bronchial tubes is shown in Fig. 9.13.

9.13 Radon and Animals Living in Underground Burrows Since radon enters the atmosphere from the ground, then in earthen burrows where many animals live, radon concentration must be increased. Many mollusks, amphibians, reptiles, insects, some fish, and even birds, such as shore swallows, live in earthen burrows. But the leading interest for us is, of course, mammals. In underground burrows live moles, badgers, chipmunks, gophers, beavers, rabbits, foxes, and many others. Such a large animal as a bear spends a long time in an earthen den. There are mammals that do not leave their holes at all, for example, the mole voles and the naked mole rat (Fig. 9.14). Many works have been published on studying the radiation situation in animal burrows, particularly on measuring the radon concentration. It is clear that there is a significant variation in concentrations depending on the soil type. You can specify an average value of ~10 thousand Bq/m3, but the concentration reached 20 thousand Bq/m3 in many burrows. Recall that the typical values for fresh air are ~10 Bq/m3, and in the premises ~50 Bq/m3.

Fig. 9.13  Scheme of changes in the bronchi as a result of smoking

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Fig. 9.14  Naked mole rat cubs in the demonstration chamber of the Underground Life Section of the Indio Zoo, California. Shooting by the author through the protective glass of the camera. During the shooting, the animals did not sleep but were in constant motion

The author does not know the work on the morbidity of burrowing animals, but it can be noted that many species of animals have been using earthen burrows for millions of years. Scientists have recently discovered burrows that are thought to be inhabited by dinosaurs. One of them was discovered in the state of Montana in the United States in 2006, and the other one more recently on the southeast coast of Australia. This burrow is believed to be approximately 110 million years old. The dinosaurs eventually died, but not because of radon. If the underground life would lead to many diseases and a weakening of the population, animals would change their habitat in the process of evolution. But no, they continue to live in burrows. Burrowing animals not only live safely in conditions of high radon concentrations, but some rodents, particularly naked mole rats and mole voles, have a very long-life expectancy, but the species’ mortality rate does not increase with age. They demonstrate high resistance to cancer and oxygen deprivation. The life expectancy of this rodent reaches 40 years (whereas for a usual mouse, it is not more than a year and a half ). Many scientific groups are now studying these rodents to combat aging and cancer. Researchers indicate different reasons for the special properties of these rodents: telomerase activity, a high level of DNA repair systems, etc. But we will point out one more here. Longevity and a small proportion of diseases of naked mole rats are a manifestation of radon therapy.

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9.14 Radon Therapy 9.14.1 What Is Radon Therapy, and from What Diseases It Helps According to historians, radon therapy, radon treatment, has been known since prehistoric times. Only in those days, it was not suspected that it was radon that had a therapeutic effect. It is believed that therapeutic procedures with already identified radon, which we now call radon therapy, began to be used in the European resorts of Bad Kreuznach in Germany and Bad Gastein in Austria in 1904. The list of diseases considered subject to radon therapy has dozens of names. The impact of radon baths is reflected in their analgesic and soothing effect in the complete or partial regeneration of inflammation. Bechterew’s disease occupies the first place in the list of indications—ankylosing spondylitis, inflammation of the intervertebral joints, which leads to their ankylosis (fusion), which is why the spine is as if in a rigid case that restricts movement. This is followed by other spine diseases, such as spondylitis, spondylarthrosis, osteochondrosis, degenerative or deforming diseases of the joints, and rheumatoid processes in the muscles, tendons, and joints. Chronic neurological diseases, such as neuralgia or chronic neuritis, and chronic skin diseases, such as scleroderma, psoriasis, and eczema, often respond well to radon therapy. Subordinate to radon and respiratory diseases—bronchial asthma, bronchitis, and sinusitis, allergic disorders—hay fever and neurodermatitis. It is believed that radon therapy also affects the endocrine system, is useful for menopausal symptoms, and increases potency and sexual desire. Radon treatment is credited with the effect of rejuvenation. Radon therapy includes radon baths, where the whole body is immersed, or irrigation with radon water of individual body parts, for example, in gynecology. Microclusters or applications are also used. Sometimes radon water is prescribed orally to treat diseases of the stomach and intestines. Another option for using radon is inhalation therapy, breathing with air saturated with radon. Such procedures are called speleotherapeutic. Interest and attention to radon therapy are because official modern medicine copes well with acute diseases and is much less successful in treating chronic conditions, with incomprehensible reasons and confusing courses. Long-term treatment with painkillers and anti-inflammatory drugs often

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leads to undesirable side effects, eventually losing its effectiveness, and, in addition, the cost of such treatment is very noticeable. Radon treatment for a reasonably long period relieves pain and suppresses inflammation and is quite tolerable financially. The experience accumulated over many years shows that the doses used in radon therapy do not have side and long-term effects. A typical course of treatment consists of 10 procedures taken every other day, for 20–30 minutes in a bath of 150 liters, usually at a temperature of 36–37 °C. Sometimes, if conditions permit, therapeutic sessions are held in natural bodies of water, as shown in Fig. 9.15. Inhalation procedures, for example, in the Austrian balneological spa of Bad Gastein are carried out at a radon concentration in the air of ~40 kBq/ m3. During three weeks, patients receive six procedures lasting half an hour each.

Fig. 9.15  Treatment procedure in the source of radon water in Hungary. Figure from The Cave Bath and Aquatherapy in Miskolztapolca, Barlangfürdö, Thermal Hungary— https://www.thermalhungary.net/item/miskolctapolca-­barlangfurdo/. With permission of Miskolc Fürdők Kft—A Miskolc Csoport tagja

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9.14.2 Where the Famous Radon Resorts Are Radon therapy is part of the spa system, where any healing water can be used, not only radon. Often such resorts are called “spas.” The name comes from the Belgian city of Spa in the Ardennes Mountains, whose mineral springs have been known since Roman times. Sometimes the term “spa” is proposed to be considered an abbreviation of the Latin phrase “Sanitas per aquas” (health through water). The most famous, long-working radon hospitals are located in Europe. Resorts with mineral waters in Germany, Austria, and the Czech Republic (currently 17 resorts) organized EURADON—European Association Radon Spas (Verein Europäische Radonheilbäder e. V.), later they were joined by Poland. European countries together not only use natural radon sources as a means of treating various diseases but also conduct scientific severe research on the effects of radon on humans. Radon hospitals exist in France, Italy, Hungary, Bulgaria, and Greece. Radon also attracts populations on other continents. Radon springs in Misasa, Japan, have been known for 800 years. Therapeutic procedures with radon water are not released at the radon resort on the island of Hainan in China. Still, the waters of thermal radon springs fill the pool sectors and enter the baths of the most expensive rooms of a five-star hotel. New radon spas have been built in South America (Chile, Brazil), Japan, and China. The United States does not officially recognize radon baths as a medical procedure. Yet, thousands of people visit the old uranium mines near Boulder, Colorado, every year, and some patients have been returning for decades. Radon Health Mines, located in the mountains of Montana, USA, is also popular, where not only Americans come but also residents of Canada. In these mines, there are no medical personnel. Radon treatment here is carried out independently at the discretion of visitors. In the former USSR and Russia, there are many sources of radon water in Altai (Belokurikha), Karelia, Transbaikalia, the North Caucasus, and many other places. The most famous is the Institute of Balneology in Pyatigorsk in the foothills of the Caucasus. In Russia, radon therapy is not limited to places where radon water comes out. Many clinics and sanatoriums receive radon from radium preparations and prepare “artificial” radon water. Currently, about 75 thousand patients receive annual treatment at radon spas in Germany and Austria. The course of treatment takes about 3 weeks, and the health care system pays not only the costs of treatment but also travel and accommodation. In addition, many patients come to the resorts and pay

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for treatment at their own expense, often returning regularly, as there are obvious positive results. The concentration of radon in mineral waters varies within very significant limits. The largest concentrations of radon, apparently, have the waters of the Bismarckquelle spring in the Saxon town of Bad Schlema, located in the Ore Mountains, Germany, up to 40 thousand Bq/l, somewhat less in the source of Wettiner (Wettinerquelle) in the town of Bad Brambach, also in Saxony, up to 26 thousand Bq/l. However, smaller concentrations are usually used in medical procedures—about several thousand becquerels per liter, i.e., natural waters are diluted. Please note that the radon concentration in gas (in air) is usually measured in Bq/m3, and in water in Bq/l. Radon hospitals are often located in beautiful resort places, and a variety of health procedures, including massage, saunas, hot sand beds, mud therapy, etc., can accompany sessions. The appearance of one of the balneological centers in Europe is shown in Fig. 9.16. The Gastein Valley is characterized by its natural abundance of water. Around 5 million liters of warm thermal water emerge from the springs daily, supplying numerous spa and therapy centers and the Gastein thermal baths.

Fig. 9.16  The appearance of one of the balneological centers of Europe. Radon spring in Bad Gastein (Austria). Die Felsentherme in Bad Gastein. Figure from Salzburger Land Tourismus GmbH—https://www.salzburgerland.com/de/bad-­gastein/veranstaltungen. Creator: Max Steinbauer 5640 Bad Gastein, With permission of SalzburgerLand Tourismus GmbH, Susanne Kolmbauer, Urlaubsberatung and Informationsmanagement

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Enriched with the valuable noble gas radon, the water has a healing effect on illnesses and relieves tension. The Alpentherme in Bad Hofgastein and the Felsentherme in Bad Gastein invite you to relax after an exciting day of skiing or hiking.

9.14.3 Real Results of Radon Treatment The results of radon therapy have been and are being seriously analyzed. Clinical studies have been conducted as prospective, randomized, placebo-­ controlled, double-blind studies whenever possible, in which neither clinicians nor patients knew what treatment was being given to this group. This organization of research corresponds to the highest possible degree of scientific certainty. Not all known studies correspond to this level, but a sufficient set of works has already accumulated so that it is possible to draw serious conclusions. And radon therapy shows remarkable results with such a severe approach to research and a thorough analysis of the results. Epidemiological studies of radon therapy patients have shown its effectiveness in sustained pain relief, a decrease in stress, and a decrease in the consumption of painkillers compared to the control group. The therapeutic effect was preserved mainly for many months after the end of therapy, up to a year. Although the reduction in the feeling of pain is a subjective sensation, they tried to determine it as objectively as possible, according to the threshold of pain pressure, using special devices—algesimeters. Such devices determine pain even in wordless animals, such as rabbits. Irrigation with radon water in gynecology led to a decrease in the number of urinations per day, a decrease in the duration of urination, and an increase in the volume of urine and the rate of release of the bladder. The analgesic effect could also be observed in the control group taking baths with carbon dioxide but without radon. However, the analgesic effect in the control group disappeared soon after the termination of the procedures, and in radon therapy patients, it lasted up to a year. Although the subjective feelings and symptomatic changes of radon spa patients play a decisive role in assessing the effectiveness of radon therapy, many more apparent indicators of effectiveness are changes in the body at the molecular and cellular levels that characterize the therapeutic effect of radon exposure. Such changes observed in microscopic studies could be considered objective signs of the healing effects of radon.

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Evidence of positive cell changes under the influence of small doses of alpha radiation was observed in vitro and in vivo, in tissue cultures, in animals, and in humans. Most of the diseases that are treated with radon therapy are inflammatory in nature. Microscopic studies show that when irradiated with small doses of alpha particles, there is a statistically significant increase in various cellular components undergoing transformation and secretion. I will not bore the reader with the designations of these cells—monocytes, macrophages, and cytokines, but it is essential that they all have an anti-inflammatory spectrum of action. Therefore, we can conclude that suppressing inflammation and reducing pain is not self-hypnosis, not a placebo effect, but a real medical fact. Interestingly, during the treatment with radon, a significant increase in the concentration of the female sex hormone estradiol in women in menopause and the male sex hormone testosterone in men was recorded.

9.14.4 Possible Mechanism of Therapeutic Action of Radon Since the therapeutic effect of radon is becoming more and more apparent, it is necessary to try to understand what the mechanism of its therapeutic effect is. Radon decay products emit short-range alpha particles, which can only affect the nerve endings in human skin during the balneological procedure. Radon itself is atoms of a noble gas that do not enter into chemical interactions and do not stick to the surfaces of bodies. But the decay products are metal atoms that can settle on surfaces. Since Curie and Rutherford, such settled radioactive atoms are called active sediment. Active sediment is deposited on the body’s surface and exposes the skin to alpha particles about three hours after leaving the bath. Radon can also penetrate the blood vessels by diffusion through the skin and transfer to the internal organs. However, the radiation dose to the internal organs compared to the skin is negligible. Estimates show that approximately 90% of the absorbed radiation energy is concentrated in the skin. Alpha particles in the skin do the same thing as mustard plasters, jars, or acupuncture, stimulating the body’s defenses. Approximately in the same way, the reflexogenic zones of the respiratory tract are affected by radon during inhalation therapy.

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Molecular and cellular reactions that lead to therapeutic effects have been investigated with X-ray irradiation and ultraviolet radiation. The same reactions were observed when irradiated with alpha particles. The main effect of exposure to low doses of alpha particles was to reconfigure the cellular immune response, mainly due to cell apoptosis associated with the release of anti-inflammatory cytokines, the secretion of which was recorded in the results of the analyses. Since the biophysical effect is achieved at very low doses of radiation, the question arises as to how, at such small doses, a reduction in chronic inflammatory pain and a stop in tissue destruction are achieved. To clarify this issue, the “bystander effect” is involved (Sect. 6.6). It has been experimentally obtained that when an alpha particle hits only one cell, up to 40 cells are affected, i.e., the “multiplication coefficient” was up to 40. The above positive results of radon therapy have not yet changed the attitude of state and international organizations toward it. Major official organizations, agencies, and committees, such as the World Health Organization (WHO) or the U.S. Environmental Protection Agency (US EPA), consider radon hazardous to health and do not recognize radon therapy. There are no openly operating radon balneological spas in the United States, the use of radon for treatment is treated as alternative or complementary medicine, something like homeopathy or even shamanism. Radon therapy is compared to acupuncture, naturopathy, and treatment with crystals and magnets. In the United States, radon is only used in inhalation procedures in older mines at the peril of patients outside the health care system and is not covered by health insurance. According to the ethical researcher of radon therapy, Barbra Erickson, many visitors to radon mines do not inform their doctors, friends, or family members about the decision to use radon for treatment. In Europe, radon therapy exists in a completely different cultural context. Although it is also not officially supported, thanks to many years of practice, many resorts that use radon in all possible forms successfully operate in many European countries. Despite the authorities’ warnings, thousands of residents annually visit facilities where radon treatment can be obtained. In numerous spas, not only treatment is carried out, but also the study of the effect of radon on health as part of balneological and speleotherapeutic procedures.

10 The Necessity of Low Radiation Doses: Experiments in Underground Laboratories

10.1 History of the Question In the second half of the twentieth century, the first reports appeared in the scientific literature that the natural background radiation is necessary for the normal growth and development of a living organism, and reducing the background below the natural one has a depressing effect. In 1966, at the III Congress on Radiation Research, Hubert Planel reported that when shielding the external background radiation in the lead box, the infusoria divides and develops noticeably worse than under normal conditions. Restoration of the natural background radiation (introducing a weak source of thorium-232 behind the lead screen) eliminated the depressant effect. Subsequently, H. Planel and his collaborators from the Laboratory of Radiobiology and Space Biology in Toulouse, France, conducted extensive research on the effects on various microorganisms and small animals of reduced and increased doses of radiation. The studies were carried out in shielded boxes in the underground laboratory of the Center for Scientific Research (Centre de la Recherche Scientifique—C.N.R.S.) Moulis in the Pyrenees Mountains; in the glaciological laboratory C.N.R.S. in Chamonix at an altitude of 3800 m, on balloons-probes; on the spacecrafts Apollo-16 and 17, Cosmos-782, 936, 1129, and 1887; and on the space stations Salyut-6 and 7. Two species of protozoa were followed: Paramecium tetraurelia and cyanobacterium Synechococcus lividus. In all cases, measures were taken to ensure that the level of radiation was the only factor distinguishing between experience and control. The temperature, the pressure, the light, the composition of the environment in which the bacteria grew, and the cell concentration © The Author(s), under exclusive license to Springer Nature Switzerland AG 2023 I. Obodovskiy, From Radio-phobia to Radio-euphoria, Springer Praxis Books, https://doi.org/10.1007/978-3-031-42645-2_10

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were maintained the same way. In all cases, the increased level of radiation compared to the normal background stimulated the growth and development of bacteria and the reduced—suppressed. Planel’s research was picked up in the United States by Thomas Luckey and in the USSR, in Pushchino, at the Institute of Biophysics of the USSR Academy of Sciences by A.M.  Kuzin. For more on Luckey’s work, see Sect. 8.4.1. In 1977, a low-background camera was created at the Institute of Biophysics of the USSR Academy of Sciences (Pushchino), which made it possible to conduct experiments with higher plants and animals in conditions of reduced external natural background radiation. Inhibition of growth and development in such conditions was found. At the same time, the introduction of the low-­ background chamber of a source that restores the radiation background completely eliminated the oppression of development. The researchers drew attention to the fact that only external irradiation was reduced in the shielded chambers. In contrast, internal irradiation, primarily from potassium-40, which was part of the nutrient medium, remained unchanged. Experiments in which both the external and internal components of the radiation background decreased simultaneously showed that developmental inhibition was recorded to a much greater extent in this case. Similar patterns were revealed in experiments on growing mice in a shielded chamber, which were added to food potassium chloride, free of radioactive potassium-40. The growth and weight gain rate decreased by up to 50% compared to the control. The works of Planel, Luckey, and Kusin are well-known and widely cited. Less known are the works of the German scientist J.  Eugster. In 1964, he published an article on sub-radiation experiments and, in 1966, on the biological importance of natural radiation. In 1966, in the Academy of Sciences of the Georgian Republic proceedings, A.A. Kozlov reported on the results of a study of the effect of a reduced radiation background on the development of Protozoa. Thus, in independent experiments performed in the second half of the XX century in different countries by different methods on different living objects, it was shown that natural background radiation significantly affects living organisms. In the experiments conducted with laboratory animals, plants and microorganisms that have been in conditions of a radiation background reduced several times for a long time, the growth of bacterial colonies and tissue cultures slowed down, and animals lost weight and became less active and less intelligent. There were signs of anemia and severe immunodeficiency, accompanied by the development of infectious processes and malignant

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tumors. Morphologically, atrophic changes similar to accelerated aging were found in their tissues. Life expectancy was reduced. A complex of such signs is called “radiation deficiency syndrome.”

10.2 Underground Low-Background Laboratories The pioneering work of Planel, Luckey, and Kusin, briefly described above, has revealed the existence of a new problem and has sparked a new phase of research into the existence of life in conditions of reduced background radiation. This research continues on a much larger experimental basis in several of the world’s leading low-background underground laboratories. Currently, there are about twenty well-equipped underground laboratories on almost all continents. The main direction of their work is low-background high-energy physics: the search for dark matter and dark energy, the registration of neutrinos, the search for rare nuclear–physical events such as double beta or proton decay, and others. In some of the underground low-background laboratories, biological experiments in conditions of reduced background radiation are already being conducted; in others, the upcoming research program is still being discussed, and the construction of some laboratories is only planned. Recent publications from 2020–2022 show that a new scientific direction called “underground radiobiology” has formed. Connecting with this new term has appeared: “Below background radiation biology.” Since the composition and density of terrestrial rocks located above laboratories and the ability of these rocks to break particles can vary markedly, for the convenience of comparing the protection of different laboratories from cosmic rays, the depth of the location of underground laboratories is usually measured in meters of water equivalent (m.w.e.)—the thickness of such a layer of water, the absorption capacity of which for cosmic rays is the same as that of the sum of rocks above the laboratory. As a rule, measurements are carried out in parallel in an underground laboratory, with a reduced background, and ground, with a normal, natural background. When measuring, all measures were taken to ensure that the conditions in the above-ground and underground laboratories differ only in radiation doses. The same temperature, pressure, humidity, atmospheric composition, and day and night change regime are maintained, and biological objects of measurement receive the same nutrition.

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Underground laboratories are divided into two types: laboratories with horizontal access—tunnels, usually located next to railway and/or automobile tunnels, and laboratories with vertical access—mines. It is believed that laboratories in tunnels, more precisely next to tunnels, have certain advantages. For example, it is more convenient to deliver large-sized equipment. In the Gran Sasso Laboratory, ground rooms are located near the entrance to the tunnel; moving from the ground to the underground premises, and back takes little time, and measurements in both rooms can be carried out by the same operator, which eliminates some possible sources of scattering of measurement results. In some laboratories, the biological part of the research is devoted to the so-called “extremophilic” biology, the study of the life of communities of microorganisms living in the ground deep underground in extreme conditions of high temperatures, up to 120 °C, and pressures. The researchers aim to discover the sources of energy that provide life without photosynthesis, the role of ionizing radiation, and the adaptation of living organisms to exist in emergencies. Next, only those low-level laboratories in which the effects of low background on the functioning of living systems are studied will be named (Fig. 10.1). • SNOLAB. The SNOLAB (Sudbury Neutrino Laboratory) near Sudbury, Ontario, Canada, is located in an operating nickel mine at a depth of 2070 m (6010 m.w.e.). • Gran Sasso. An underground laboratory in the tunnel under Apennine, Italy. The laboratory is located at a depth of 1400 m (3800 m.w.e.). • WIPP. Waste Isolation Pilot Plant, 42 km east of Carlsbad, New Mexico, USA. Located at a depth of 650 m below the surface. • Boulby. An underground laboratory in a mine in the UK at a depth of 1100 m (2850 m.w.e.). • Modane. Underground Laboratory (French—Laboratoire Souterrain de Modane—LSM). Located in the Fréjus Road Tunnel connecting the commune of Modane in the province of Savoie in France and the city of Bardonecchia in Italy. The laboratory is located at a depth of 1700  m (4800 m.w.e.). • CJEML Underground Laboratory in China, which conducts biological research, is located in the Erdaogou Mine, about 300  km southeast of Changchun in northeast China, at a depth of 1470 m. There is at least one other underground laboratory CJPL in China, the so-called Jinping Laboratory in the Liangshan area in southern Sichuan Province, about

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Fig. 10.1  World map showing the location of underground low-background laboratories. Laboratories being designed or under construction are also noted: the first underground laboratory in South America in the Agua Negra tunnel under the Andes between Chile and Argentina (ANDES—Agua Negra Deep Experiment Site) at a depth of 1750 m (4800 m.w.e.), the Stawell Laboratory in a mine in Australia (SUPL—Stawell Underground Physics Laboratory) and the new Yangyang Laboratory (Y2L) in South Korea. Figure from Aldo Lanni. Science in Underground Laboratories and DULIA-Bio. Mini-review article. Front. Phys., 23 February 2021, with additions by the author. https://www.frontiersin.org/articles/10.3389/fphy.2021.612417/full. CC-BY

500 km southwest of Chengdu City in central China. The laboratory is located at a depth of 2400 m (6720 m.w.e.), making it the world’s deepest underground laboratory. So far, only physical studies are being conducted in the Jinping Laboratory. We also note that, in mines, various convenient for placement cavities can be on several, sometimes on many, horizons. Above are the depths of already mastered laboratory premises. Over time, experiments can spread across other horizons. The author suggests that in the future some other already existing underground laboratories will announce biological programs. The interest in the results of biological research in low-background laboratories is huge. Physicists, who use most of the laboratories, build huge installations there for kilotons of matter. To place a cuvette with bacteria or a chamber with flies, biologists need very little space, which physicists can give to biologists. Background conditions in underground laboratories are determined by cosmic muons, gamma quanta from radioactive nuclides in the walls and

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structural materials, neutrons of spontaneous fission and nuclear reactions, radon and radioactive nuclides potassium-40, carbon-12, and tritium contained in the research objects. The depth of the foundation uniquely determines the muon flow. A list of modern underground low-background laboratories is given on the graph of the dependence of the background of space muons on the depth of the laboratory laying (Fig. 10.2). Laboratories in which studies of the effect of low background on the life of various organisms are carried out are marked with squares (red), and a list of these laboratories is given in the left part of the graph. Since the cosmic background is not the only source of background radiation in the laboratory, knowing the dependence of the muon flux on the depth and the relationship of the flow to the dose rate, it is possible to determine the depth beyond which it makes no sense to go deeper. A typical cosmic background on the surface creates a dose rate of about 30–40 nGy/h. In the purest laboratory, the radiation background, due to all other sources except the cosmos, creates a dose rate at the level of 1 nGy/h.

1

Muon flux density, m-2s-1

10-1

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WIPP, USA mine

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HADES, Belgium, mine SUL, Ukraine, mine Yangyang, South Corea, tunnel Canfranc, Spain, tunnel Soudan, USA, mine Kamioka, Japan, mine Stawell, Australia, mine INO, India, mine Calliolab, Finland, mine Sanford, USA, mine Baksan, Russia, drift ANDES, tunnel, Chile-Argentina Jinping, China tunnel

CJEML, China, mine Modane, France, tunnel

10-5

SNOLAB, Canada, mine

10-6 0

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Depth of laboratory, kilometers of water equivalent (km.w.e.)

Fig. 10.2  Flux density of cosmic muons in the underground laboratory in dependence on the depth of the deposit. Laboratories in which the effect of low background on the existence of various organisms is studied are marked with squares (red), and a list of these laboratories is given in the left part of the graph. The direct dotted line on the graph is an exponent. For comparison, the flux density of space muons at the surface (at sea level) is ~100 m−2 s−1

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Thus, for the cosmic background to become negligible, it is necessary to weaken it by about 100 times. At the first hundred meters, the muon flux decreases very quickly. At a greater depth, this decrease slows down. For the necessary reduction in the cosmic background, it is enough to place the laboratory at a depth of more than 500 m.w.e. It should be noted that different laboratories are located in different ways relative to the surface. If the laboratory is located under a flat earth’s surface, such laboratories are usually located in mines, then the official depth is the minimum path of cosmic particles falling vertically. Particles falling at an angle travel longer paths. If the laboratory is located under mountain peaks, then particles falling at different angles can go through comparable or even smaller paths. This can increase the cosmic background. For example, Fig. 10.3 with the mountain profile shows how the laboratory location’s depth is determined. As you can see, placing an underground laboratory at a depth of more than 500–1000 m.w.e. is unnecessary. However, as a rule, biologists do not have their own underground laboratories but are located in the laboratories of physicists and use what they have got. However, physicists also use existing mines or cut-down premises near existing tunnels. As far as the author knows, the only purely biological underground laboratory is the CJEML Laboratory. The only physical underground laboratory with horizontal access, located not next to an already finished transport tunnel but in a horizontal dead-end shaft, is the Baksan Laboratory in the North Caucasus in Russia. Low-background materials are selected to reduce the gamma background from radioactive nuclides in the walls and details of the structure, and the walls are covered with layers of special weakly radioactive concrete. For example, it is known that one of the best materials for protection against gamma radiation is lead, but in the lead freshly smelted from ore, there may be a Laboratory Gran Sasso

1400 m

Rome

The Adriatic

Fig. 10.3  Determination of the depth of the location of the underground Gran Sasso Laboratory. Figure on the basis of the sites of INFN and Gran Sasso Laboratory

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decay product of uranium-238—an isotope lead-210 with a half-life of 22 years. Therefore, scientists try to use old lead instead of lead smelted from ore. For example, the European HADES Laboratory to protect against gamma radiation old lead, 300–500 years old from Versailles and Hampton Court, and sheets of the lead roof of the Dominican monastery of Het Pand in Ghent, 800  years old used. Sometimes scientists manage to get lead ballast from sunken old ships. On the contrary, copper parts are usually taken to the underground room as fresh as possible directly from the copper smelter to minimize the danger of activation by cosmic rays. In the SNOLAB Laboratory, to protect against dust that can introduce radioactive substances into the laboratory, the laboratory is designed as a “clean” room, similar to the corresponding premises of pharmaceutical or semiconductor industries. The equipment brought into the laboratory is thoroughly cleaned, and the staff take a shower and change clothes before descending into the laboratory. The chamber for experiments of the American Laboratory WIPP was shielded with 6 inches of thick steel obtained before World War 2. Effective ventilation systems reduce the radon content. Typical values are about 20–80 Bq/m3 but can be reduced to 5 Bq/m3. Readings show that a radon concentration of ~5 Bq/m3 forms a dose rate of ~1.7 nGy/h. The activity of potassium-40 and carbon-14 in the study subjects, mainly in nutrient media, is ~100 Bq/l of potassium and ~ 5∙10−2 Bq/l of carbon. The dose values to which these flux densities lead and the total activity in the underground and for comparison in the above-ground laboratories are given in Table 10.1.

Table. 10.1  Typical radiation conditions in the ground and underground laboratories (compiled by the author on the basis of dosimetric information from the laboratories of Gran Sasso, Modane, and Canfranc) Background components Cosmic rays Neutrons from cosmic rays Gamma quanta Rn K-40 Total (rounded)

Ground laboratory, nGy/h

Underground laboratory, nGy/h

40 3