Environmental Health - Theory and Practice: Volume 1: Basic Sciences and their Relations to the Environment 3030644790, 9783030644796

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Ramesha Chandrappa Diganta Bhusan Das

Environmental Health Theory and Practice Volume 1: Basic Sciences and their Relations to the Environment

Environmental Health – Theory and Practice

Ramesha Chandrappa • Diganta Bhusan Das

Environmental Health – Theory and Practice Volume 1: Basic Sciences and their Relations to the Environment

Ramesha Chandrappa Environmental Management Policy Research Institute Bangalore, India

Diganta Bhusan Das Department of Chemical Engineering Loughborough University Loughborough, Leicestershire, UK

ISBN 978-3-030-64479-6    ISBN 978-3-030-64480-2 (eBook) https://doi.org/10.1007/978-3-030-64480-2 © Springer Nature Switzerland AG 2021 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, 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

The authors dedicate this book to Corona Warriors, which include but not restricted to frontline doctors, paramedical staff, and waste management personnel, who worked tirelessly despite imminent dangers to their lives during the COVID-19 outbreak. Our sincere condolences go to all those who lost their lives in the battle against the virus.

Preface

While we were working on this two-volume book for the last 2 years, sitting in two opposite hemispheres of the world and were moving towards completing it, COVID-19 shook the world. As authors, we have now suddenly learnt a great many things in just a few months while being locked down in our respective countries. Diseases do not simply search for people and attack them. We, as human beings, invite them to us by producing chemicals and releasing them into our environments or invading forests and wild landscapes, which harbor viruses that jump to new hosts – humans – from the conventional hosts – wild animals. However, it was great to see most of the civic society across the world self-distancing or self-quarantining themselves as the case may be and stayed wherever they could to tackle the COVID-19 pandemic. Vested interest and corruption are some of the reasons why pollution goes unabated, waste goes unmanaged, and the environment goes unprotected. As natural forests become fragmented, urban settlements integrate, bringing people closer, thereby increasing the risk of infection and other ailments. Bushmeat and wet markets act as springboards to pass on the pathogens in the wild to civic society. Destruction of biodiversity creates the conditions for new diseases with profound economic and health impacts. Species in degraded habitats infect humans, and when they reach urban ecosystems, the systems get an amplified effect. With the destruction of landscapes and the wild species, humans get the diseases. Like all living beings, pathogens grow and reproduce, which requires energy from food. They are mobilized from one species to another via either the food chain or social activity or accidental contacts. When the pathogens reach humans, their biological activity (e.g., spreading and transmission) flourish as humans live in closely packed environments. Diseases spring up in the urban environment as humans have created densely packed settlements for themselves with rodents and pets, facilitating the spread of pathogens from species to species due to close interaction.

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Indeed, pollution and pathogens do not respect political boundaries. Humans are creating channels for the spread of diseases by decreasing the natural barriers between themselves and the usual hosts, that is, the animals, in which pathogens are naturally circulating. Consequences of environmental alterations are different at different scenarios. After going through many literatures and walking through many countries, cities, and streets, we would like to share our learning in the form of this book, so that the knowledge baton can be passed on to the future generations. The general saying “one solution does not suit all circumstances” holds well for environmental health also. Furthermore, with the changing scenarios, new solutions would arise. At the time of completion of this book, the world was facing a severe challenge from COVID-19, imposing restrictions and declaring self-quarantine to safeguard millions from the invisible virus. This situation has reduced air pollution, noise pollution, and to some extent water pollution due to reduction in manufacturing as well as trade activity. The COVID-19 pandemic resulted in the reduction in other diseases related to the environment! Traffic accidents have reduced, social distancing has reduced spreading of other infectious diseases, closure of pubs has reduced alcoholism, and travel restriction has helped to reduce waste burden in tourist places. People around the world have reacted to the situation and old theories have been tested with new theories and practices. COVID-19 has surprised the world wherein the developed countries, which have better built environment and medical infrastructure along with strong knowledge base, have suffered more compared to the developing ones. That means we need to learn much more than what we already know and respond to many such problems that humankind may face in the future. We envisage that this book will catalyze success wherein people at different capacities can take better decisions or recommend a better possible solution to decision makers for betterment of human lives. To help readers understand the interrelated concepts of fundamental science to that of many applied solutions, the book is written in two volumes. Volume I concentrates on fundamentals of sciences related to environmental health while Volume II concentrates on coping with environmental health by mitigation and adaptation strategy. We would like to thank all past authors whose work is cited in this book apart from anonymous proposals and book reviewers who showed us the way we travelled over the last 2 years. The preface would be incomplete without our acknowledgement to Springer Nature Switzerland AG whose continued encouragement and guidance have made us work towards this book. Bangalore, India  Ramesha Chandrappa Loughborough, Leicestershire, UK  Diganta Bhusan Das (December 2020)

Contents

Part I Introduction to Basic Sciences 1 Fundamentals of Chemistry for Environmental and Medical Professionals ��������������������������������������������������������������������������������������������    3 1.1 Introduction��������������������������������������������������������������������������������������    3 1.2 General Chemistry����������������������������������������������������������������������������    4 1.2.1 The Gas Laws ����������������������������������������������������������������������   13 1.2.2 Solutions ������������������������������������������������������������������������������   18 1.3 Physical Chemistry ��������������������������������������������������������������������������   18 1.3.1 Thermochemical Reactions��������������������������������������������������   19 1.3.2 Osmosis��������������������������������������������������������������������������������   20 1.3.3 Dialysis ��������������������������������������������������������������������������������   21 1.3.4 Electrochemistry ������������������������������������������������������������������   21 1.4 Catalytic Chemistry��������������������������������������������������������������������������   21 1.4.1 Chemical Kinetics����������������������������������������������������������������   22 1.4.2 Adsorption����������������������������������������������������������������������������   24 1.5 Inorganic Chemistry��������������������������������������������������������������������������   24 1.6 Organic Chemistry����������������������������������������������������������������������������   25 1.7 Equilibrium Chemistry���������������������������������������������������������������������   29 1.8 Colloid Chemistry����������������������������������������������������������������������������   32 1.9 Biochemistry ������������������������������������������������������������������������������������   33 1.9.1 Biogeochemical Pathways����������������������������������������������������   35 1.10 Nuclear Chemistry����������������������������������������������������������������������������   42 References��������������������������������������������������������������������������������������������������   45 2 Fundamentals of Physics for Environmental and Medical Professionals ��������������������������������������������������������������������������������������������   49 2.1 Introduction��������������������������������������������������������������������������������������   49 2.2 General Physics��������������������������������������������������������������������������������   50 2.3 Solid Mechanics��������������������������������������������������������������������������������   57 2.4 Fluid Mechanics��������������������������������������������������������������������������������   59 2.4.1 Density and Its Importance ��������������������������������������������������   60 ix

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2.4.2 Pressure of Fluid at Rest ������������������������������������������������������   60 2.4.3 Flow in Pipes������������������������������������������������������������������������   61 2.4.4 Flows Around a Body ����������������������������������������������������������   64 2.4.5 Scales of Environmental Fluid Processes and Systems��������   66 2.5 Optics������������������������������������������������������������������������������������������������   67 2.5.1 Basic Behavior of Light��������������������������������������������������������   68 2.5.2 Frequency������������������������������������������������������������������������������   68 2.5.3 Wavelengths and Colors��������������������������������������������������������   69 2.5.4 Angle of Incidence, and Refraction��������������������������������������   69 2.5.5 Index of Refraction ��������������������������������������������������������������   69 2.5.6 Snell’s Law����������������������������������������������������������������������������   70 2.5.7 Total Internal Reflection ������������������������������������������������������   71 2.5.8 Interactions with Materials ��������������������������������������������������   71 2.5.9 Prism ������������������������������������������������������������������������������������   71 2.5.10 Lenses ����������������������������������������������������������������������������������   73 2.5.11 Chromatic Dispersion ����������������������������������������������������������   74 2.5.12 Mirror������������������������������������������������������������������������������������   75 2.6 Acoustics������������������������������������������������������������������������������������������   76 2.6.1 Wave Terminology����������������������������������������������������������������   77 2.6.2 Sound Energy Density����������������������������������������������������������   77 2.6.3 Sound Intensity ��������������������������������������������������������������������   78 2.6.4 Intensity Level����������������������������������������������������������������������   78 2.6.5 Sound Pressure Level������������������������������������������������������������   79 2.6.6 Sound Power Level ��������������������������������������������������������������   79 2.7 Electrical and Electronics ����������������������������������������������������������������   80 2.8 Thermal Physics��������������������������������������������������������������������������������   84 2.9 Thermodynamics������������������������������������������������������������������������������   86 2.9.1 First Law of Thermodynamics����������������������������������������������   89 2.9.2 Second Law of Thermodynamics ����������������������������������������   90 2.9.3 Third Law of Thermodynamics��������������������������������������������   90 2.9.4 Survival in Cold Climates ����������������������������������������������������   91 2.9.5 Survival in Hot Climates������������������������������������������������������   91 References��������������������������������������������������������������������������������������������������   91 3 Fundamentals of Biology for Environmental and Medical Professionals ��������������������������������������������������������������������������������������������   95 3.1 Introduction��������������������������������������������������������������������������������������   95 3.2 General Biology��������������������������������������������������������������������������������   98 3.3 Microbiology������������������������������������������������������������������������������������  101 3.4 Interrelation Between Environment and Human/Animal Health������  112 3.4.1 Zoonosis��������������������������������������������������������������������������������  113 3.4.2 Vector-Borne Diseases����������������������������������������������������������  120 3.4.3 Impact of Poor Environmental Management on Human and Animal Health����������������������������������������������  121 References��������������������������������������������������������������������������������������������������  126

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Part II Introduction to Environmental and Medical Sciences 4 Introduction to Environmental Sciences������������������������������������������������  131 4.1 Introduction��������������������������������������������������������������������������������������  131 4.2 Micro- and Macro-Environment ������������������������������������������������������  132 4.3 Physical and Biotic Environment������������������������������������������������������  133 4.4 Climate Change��������������������������������������������������������������������������������  136 4.5 Pollution of the Environment������������������������������������������������������������  138 4.6 Solid Waste���������������������������������������������������������������������������������������  153 References��������������������������������������������������������������������������������������������������  169 5 Introduction to Medical Sciences�����������������������������������������������������������  175 5.1 Introduction��������������������������������������������������������������������������������������  175 5.2 Anatomy��������������������������������������������������������������������������������������������  177 5.3 Physiology����������������������������������������������������������������������������������������  178 5.4 Forensic Medicine and Toxicology��������������������������������������������������  179 5.5 Pathology������������������������������������������������������������������������������������������  181 5.6 Pharmacology ����������������������������������������������������������������������������������  185 5.7 Anesthesiology����������������������������������������������������������������������������������  186 5.8 Community Medicine ����������������������������������������������������������������������  186 5.9 Dermatology and Venereology����������������������������������������������������������  191 5.10 Obstetrics and Gynecology ��������������������������������������������������������������  194 5.11 Ophthalmology ��������������������������������������������������������������������������������  194 5.12 Orthopedics ��������������������������������������������������������������������������������������  195 5.13 Otorhinolaryngology������������������������������������������������������������������������  196 5.14 Pediatrics������������������������������������������������������������������������������������������  197 5.15 Neurology and Psychiatry����������������������������������������������������������������  198 5.16 Surgery����������������������������������������������������������������������������������������������  199 5.17 Pulmonology ������������������������������������������������������������������������������������  199 5.18 Nephrology����������������������������������������������������������������������������������������  200 5.19 Gastroenterology������������������������������������������������������������������������������  201 5.20 Oncology ������������������������������������������������������������������������������������������  202 5.21 Hematology��������������������������������������������������������������������������������������  202 5.22 Endocrinology����������������������������������������������������������������������������������  203 5.23 Epidemiology������������������������������������������������������������������������������������  203 5.24 Immunology��������������������������������������������������������������������������������������  204 5.25 Nutrition Science and Dietetics��������������������������������������������������������  205 References��������������������������������������������������������������������������������������������������  210 Part III Health and Environment 6 Public Health��������������������������������������������������������������������������������������������  219 6.1 Introduction��������������������������������������������������������������������������������������  219 6.2 Human and Environmental Conflict ������������������������������������������������  220 6.3 Impact of Pollution on Health����������������������������������������������������������  227 6.4 Impact of Climate Change on Health������������������������������������������������  234

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6.5 Impact of Solid Waste on Health������������������������������������������������������  238 References��������������������������������������������������������������������������������������������������  247 7 Occupational Health��������������������������������������������������������������������������������  257 7.1 Introduction��������������������������������������������������������������������������������������  257 7.2 Hazard Identification and Risk Assessment��������������������������������������  261 7.3 Hazard Prevention and Control��������������������������������������������������������  273 References��������������������������������������������������������������������������������������������������  285 Glossary������������������������������������������������������������������������������������������������������������  289 Index������������������������������������������������������������������������������������������������������������������  311

Abbreviations

3R Reduce, Recycle, and Reuse ABS Australian Bureau of Statistics AC Alternating Current ACM Asbestose Containing Material ADP Air-Dried Pulp AFO Amorphous Ferric Oxide AIDS Acquired Immunodeficiency Syndrome ANN Artificial Neural Networks AOP Advanced Oxidation Process As Arsenic ASP Activated Sludge Process BaO Barium Oxide BF Blast Furnace BFS Blast Furnace Slag BMW Biomedical Waste BOD Biochemical Oxygen Demand BOF Basic Oxygen Furnace Br− Bromide BrO3− Bromate Ion C&D Construction and Demolition C4H10 Butane CaCl2 Calcium Chloride CaCO3 Calcium Carbonate CaO Calcium Oxide CBA Cost Benefit Analysis CCl4 Calcium Tetra Chloride Cd Cadmium Ce Cerium CEA Cost Effectiveness Analysis CETP Common Effluent Treatment Plant CFC ChloroFlouro Carbon xiii

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Abbreviations

CFL Compact Fluorescent Lamp CH3COOH Acetic Acid CH4 Methane CHNS Chorbon, Hydrogen, Nitrogen, Sulphur CN− Cyanide Ion CNCl Cyanogen Chloride CNS Central Nervous System CO Carbon Monoxide Co Cobalt CO2 Carbon Dioxide COD Chemical Oxygen Demand CP Cleaner Production Cr Chromium Cr2(SO4)3 Chromium Sulfate CRED Centre for Research on the Epidemiology and Disaster CRT Cathode Ray Tube CTC Carbon Tetra Chloride CTMP Chemithermal Mechanical Pulping Cu Copper °C Degree Celsius DBP Disinfection Byproduct Control DC Direct Current DCB Dichlorobenzine DDD Dichlorodiphenyldichloroethane DDT Dichlorodiphenyltrichloroethane DMP Disaster Management Plan DWAF Department of Water Affairs and Forestry Dy Dysprosium EAF Electric Arc Furnace ECF Elemental Chlorine Free EEA European Environment Agency EEE Electrical and Electronic Equipment EH&S Environment Health and Safety EIA Environmental Impact Assessment ELV End of Life Vehicle EMF Electro Magnetic Fields EMP Environment Management Plan EMPRI Environmental Management and Policy Research Institute EoL End of Life EPA Environment Protection Agency of the USA EPP Emergency Preparedness Plan EPR Extended Producer Responsibility Er Erbium EU European Union FAO Food and Agriculture Organization

Abbreviations

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FDI Foreign Direct Investment Fe Iron FMD Floating Marine Debris FML Flexible Membrane Liners FOG Fat, Oil, Grease FTW Floating Treatment Wetland GCL Geosynthetic Clay Liner Gd Gadolinium GDP Gross Domestic Product GFCI Ground-Fault Circuit-Interrupters GHG Greenhouse Gases GI Gastro-Intestine GPP Green Public Procurement GPS Global Positioning System GTZ Deutsche Gesellschaft fürTechnischeZusammenarbeit (German Technical Cooperation) H2CO3 Carbonic Acid H2CrO4 Chromic Acid H2O Water H2S Hydrogen Sulfide H2SO4 Sulphuric Acid Hb Hemoglobin HC Hydrocarbons HCB HexoChloroBenezenes HCl Hydrochloric Acid HEX-BCH Hexachlorobicycloheptadiene, Bicyclo(2.2.1)hepta-2,5-diene Hg Mercury HgCl2 Mercury Chloride HgSO4 Mercury Sulfate HHP Household Hazardous Product HHV Human Herpesvirus HHW Household Hazardous Waste HIV Human Immunodeficiency Virus HLW High-Level Wastes HSLT High Speed Low Torque IAEA International Atomic Energy Agency IARC International Agency for Research on Cancer IATA International Air Transport Association ICLEI International Council for Local Environmental Initiatives ICT Information Communication Technology IFC International Finance Corporation IFRC International Federation of Red Cross and Red Crescent IGES Institute for Global Environmental Strategies ILO International Labour Organisation ILW Intermediate Level Waste

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IMDG International Marine Dangerous Goods IPCC Intergovernmental Panel on Climate Change ISL In Situ Leach ISWA International Solid Waste Association ISWM Integrated Solid Waste Management IUCN International Union for the Conservation of Nature IUPAC International Union of Pure and Applied Chemistry IWRM Integrated Water Resource Management K2Cr2O7 Potassium Dichromate K2O Potassium Oxide KCl Potassium Chloride KOH Potassium Hydroxide kVA Kilovolt-Ampere kWh Kilowatt Hour L Liter La Lanthanum LCA Life Cycle Assessment LCD Liquid Crystal Display LDAR Leak Detection and Repair LDC Least Developed Countries LFG Land Fill Gas LILW Low and Intermediate Level Wastes LILW-LL Low and Intermediate Level Wastes-Long Lived LILW-SL Low and Intermediate Level Wastes-Short Lived LLW Low Level Waste LNWT Low or No Waste Technology lpd Liters per day LSHT Low Speed High Torque Lu Lutetium LWD Large Woody Debris LWP Limited Work Permit MCB Monochlorobenzene MCi Megacurie, 1,000,000 times a curie mCi Millicurie, 1/1000 of a curie MCM Million Cubic Meters MDG Millennium Development Goal MED Multi-effect distillation MEIP Metropolitan Environmental Improvement Programme metHb Methomoglobin MFA Material Flow Analysis MgO Magesium Oxide MLD Million Liters per Day MLSS Mixed Liquor Suspended Solids Mn Manganese MRF Material Recovery Facility

Abbreviations

Abbreviations

MRI Magnetic Resonance Imaging MSDS Material Safety Data Sheet MSEW Mechanically Stabilized Earth Wall MSF Multistage Flash Distillation MSW Municipal Solid Waste N2O Nitrous Oxide NA Not Applicable Na2S2O5 Sodium Metabisulfite NaCl Sodium Chloride NaHSO3 Sodium Bisulfite NaO Sodium Oxide NaOH Sodium Hydroxide NAPL Nonaqueous Phase Liquid Nb Niobium Nd Neodymium NDMA N-nitrosodimethylamine NF Nanofilter NFC Nuclear Fuel Cycle NGO Nongovernmental Organization NH4OH Ammonium Hydroxide Ni Nickel Ni(NO3)2 Nickel Nitrate Ni-Cd Nickel-Cadmium Ni-Cr Nickle-Chromium NiMeH Nickel Metal Hydride NIOSH National Institute for Occupational Safety and Health NMRS Nuclear Magnetic Resonance Spectrometer NO2 Nitrogen Dioxide NO3 Nitrate Nitrate ion NO3− NORM Naturally Occurring Radioactive Materials NOx Oxides of Nitrogen NTO Nanocrystalline Titanium Dioxide NTUA National Technical University of Athens NWM Nuclear Waste Management O3 Ozone ODS Ozone Depleting Substance OECD Organisation for Economic Co-operation and Development OF Overflow OPC Ordinary Portland Cement OPCW Organization for the Prohibition of Chemical Weapons OSHA Occupational Safety and Health Administration P&T Partitioning and Transmutation PAH Polycyclic Aromatic Hydrocarbon PAN Peroxy Acetyl Nitrates

xvii

xviii

Pb Lead PBDE Poly-Brominated Diphenyl Ethers PbO Lead Oxide PCB Polychlorinated Biphenyl PCDD Polychlorinated Dioxins PCDF Polychlorinated Dibenzofurans PCP Pentachlorophenol PDF Plastic Derived Fuels PDR Peoples Democratic Republic PEF Process Engineered Fuel PFA Pulverized Fly Ash PFOA Perfluorooctanoic acid PIM Potentially Infectious Material PMF Powder Metal Fuel PO4 Phosphate POHC Principal Organic Hazardous Constituents POP Persistent Organic Pollutant POST Parliamentary Office of Science and Technology POTW Publicly Owned Treatment Works PP Polypropelene PPE Personal Protective Equipment Pr Praseodymium PRB Permeable Reactive Barriers PRC Pneumatic Refuse Collection PS Polystyrene PTW Permit to Work Pu+3 Plutonium (III) Pu+4 Plutonium (IV) PVC Poly Vinyl Chloride RA Risk Assessment RBC Rotating Biological Contactors RCT Reinforced Concrete Trenches RDF Refuse Derived Fuel RDW Reactor Decommissioning Waste REF Recovered Fuel RFB River Bank Filtration RFID Radio Frequency Identification RI Rapid Infiltration RO Reverse Osmosis RSS Royal Scientific Society RTS Reservoir Triggered Seismicity RWI Recreational Water Illnesses SA Sustainable Assessment SAT Soil-Aquifer Treatment Systems Sb Antimony

Abbreviations

Abbreviations

SBA Sustainable Business Associate SBR Sequential Batch Reactors SCE Snow Cover Extent SCN Safety Clearance Notice Se Selenium SEA Strategic Environmental Assessment SHG Self Help Group SIDS Small Island Developing States SiO2 Silicon Dioxide SLF Substitute Liquid Fuel SLT Stone-Lined Earth Trenches Sm Samarium SMS Steel Melting Shop SMZ Surfactant Modified Zeolite Sn Tin SNF Spent Nuclear Fuel SO4 Sulfate SOC Synthetic Organic Compound SoEA Socioeconomic Assessment SOP Standard Operating Procedure SPW Solid Petroleum Waste SR Slow Rate SRS Sealed Radioactive Sources SST Sea Surface Temperature STP Sewage Treatment Plant SWM Solid Waste Management TA Technology Assessment Tb Terbium TBBPA Tetra Bromo Biphenol-A Tc Technetium TCF Total Chlorine Free TCU True Color Units Th Thorium TH Tile Hole THMs Triholomethanes Ti Titanium TKN Total Kjedal Nitrogen Tm Thulium TOC Total Organic Compound TRU Transuranic TRUW Transuranic Waste TSDF Treatment, Storage, and Disposal Facility TTD Tirumala Tirupathi Devastanam TWRF Tsunami Waste Recovery Facilities U Uranium

xix

xx

Abbreviations

UC European Community UDDT Urine Diversion Dehydrating Toilets UFW Unaccounted for Water UK United Kingdom ULB Urban Local Body UN United Nations UNDRR United Nations Office for Disaster Risk Reduction UNECA United Nations Economic Commission for Africa UNECE United Nations Economic Commission for Europe UNEP United Nations Environment Protection Agency UNESCO United Nations Educational, Scientific and Cultural Organization UNICEF United Nations Children Fund UNISDR United Nations International Strategy for Disaster Risk Reduction UNU United Nations University UPS Uninterrupted Power Supply USA United States of America USEPA United States Environmental Protection Agency USFA United States Fire Administration VFA Volatile Fatty Acid VLH Volatile Liquid Hydrocarbons VLLW Very Low Level Waste VOC Volatile Organic Compounds VRF Volume Reduction Factor WCED World Commission on Environment and Development WEEE Waste from Electrical and Electronic Equipment WHO World Health Organization WTE Waste to Energy WWF World Wide Fund for Nature WWTP Wastewater Treatment Plant Y Yttrium Yb Ytterbium Zn Zinc ZnO Zinc Oxide Zr Zirconium

List of Figures

Fig. 1.1 Chemical substance refers to any form of matter that has constant chemical composition of its constituent entities����������������������� 4 Fig. 1.2 A typical reactor in an industry��������������������������������������������������������������� 8 Fig. 1.3 Waste dump and stack from which emissions occur. Stoichiometric equations are often used by environmental professionals for calculating emissions from such waste dump and stack��������������������������������������������������������������������������������������� 9 Fig. 1.4 Leachates formed due to reaction among the chemicals in the solid waste������������������������������������������������������������������������������������� 9 Fig. 1.5 Oxidation occurs during combustion���������������������������������������������������� 10 Fig. 1.6 Aeration of wastewater������������������������������������������������������������������������� 10 Fig. 1.7 pH values of various water and wastewater, and discharge standards for treated wastewater����������������������������������������������������������� 12 Fig. 1.8 Schematic depiction of Boyle’s law������������������������������������������������������ 13 Fig. 1.9 Schematic depiction of Charles’ law���������������������������������������������������� 14 Fig. 1.10 Pictorial depiction of pressure law�������������������������������������������������������� 15 Fig. 1.11 Pictorial depiction of Dalton’s law of partial pressure�������������������������� 16 Fig. 1.12 The volume of 1 mol of an ideal gas at standard temperature and pressure is 22.41 L, the standard molar volume����������������������������� 19 Fig. 1.13 A typical reverse osmosis installation��������������������������������������������������� 20 Fig. 1.14 The shiny greenish surface of the statue is formed by corrosion of the copper of the statue, which forms a thin layer of an insoluble compound that contains copper, sulfate, and hydroxide ions�������������������������������������������������������������������������������� 22 Fig. 1.15 The corrosion process involves redox reaction in which metallic iron is converted to reddish-brown Fe(OH)3��������������������������� 23 Fig. 1.16 Structure of carbon atom����������������������������������������������������������������������� 24 Fig. 1.17 Arrangement of atoms in methane�������������������������������������������������������� 25 Fig. 1.18 Benzene structure���������������������������������������������������������������������������������� 26 Fig. 1.19 Different ways of representing the benzene structure��������������������������� 27 Fig. 1.20 Frothing in surface water streams due to detergents����������������������������� 30 xxi

xxii

Fig. 1.21 Fig. 1.22 Fig. 1.23 Fig. 1.24 Fig. 1.25 Fig. 1.26 Fig. 1.27 Fig. 1.28 Fig. 1.29

List of Figures

Water cycle�������������������������������������������������������������������������������������������� 36 Carbon cycle����������������������������������������������������������������������������������������� 37 Nitrogen cycle��������������������������������������������������������������������������������������� 39 Oxygen cycle���������������������������������������������������������������������������������������� 40 Phosphorous cycle�������������������������������������������������������������������������������� 41 Toxic cycle�������������������������������������������������������������������������������������������� 42 Common types of nuclear decay����������������������������������������������������������� 43 Nuclear transmutation reaction������������������������������������������������������������� 44 Neutron-induced nuclear fission����������������������������������������������������������� 45

Fig. 2.1 Schematic diagram explaining Newton’s universal law of gravitation����������������������������������������������������������������������������������������� 52 Fig. 2.2 Pictorial representation of polygon law of forces��������������������������������� 53 Fig. 2.3 Illustration of compressive strain in solids������������������������������������������� 57 Fig. 2.4 Illustration of shear strain��������������������������������������������������������������������� 57 Fig. 2.5 Schematic diagram for explaining surface tension in a fluid droplet��������������������������������������������������������������������������������������������������� 59 Fig. 2.6 Line diagram of flow with varying cross-section���������������������������������� 62 Fig. 2.7 Flow in partially filled conduit�������������������������������������������������������������� 62 Fig. 2.8 Flow in river around bodies������������������������������������������������������������������ 63 Fig. 2.9 Obstruction to free flow of storm water drains could result in stagnation of water and becoming a mosquito-­breeding place������������� 64 Fig. 2.10 Propagating light ray from a low refractive index medium to one with a higher index��������������������������������������������������������������������� 69 Fig. 2.11 Illustration of critical angle������������������������������������������������������������������� 70 Fig. 2.12 Total internal reflection������������������������������������������������������������������������� 71 Fig. 2.13 Pictorial depiction of transmission, absorption, and reflection������������� 72 Fig. 2.14 Schematic diagram of specular and diffusive reflections���������������������� 72 Fig. 2.15 Different views of a prism�������������������������������������������������������������������� 72 Fig. 2.16 Line diagram of light passing through a prism������������������������������������� 73 Fig. 2.17 A simple convex lens���������������������������������������������������������������������������� 74 Fig. 2.18 Line diagram showing the object between f and 2f������������������������������� 74 Fig. 2.19 Line diagram showing the object at f���������������������������������������������������� 75 Fig. 2.20 Line diagram showing the object between f and o�������������������������������� 75 Fig. 2.21 Line diagram showing the object at 2f�������������������������������������������������� 76 Fig. 2.22 Line diagram showing the object beyond 2f����������������������������������������� 76 Fig. 2.23 Line diagram showing the object at infinity����������������������������������������� 77 Fig. 2.24 Chromatic dispersion in a prism����������������������������������������������������������� 77 Fig. 2.25 Line diagram of incident ray and reflected ray������������������������������������� 78 Fig. 2.26 Line diagram of sound wave����������������������������������������������������������������� 80 Fig. 2.27 Line diagram explaining acoustics near field and far field������������������� 80 Fig. 2.28 Transmission and distribution of electricity������������������������������������������ 82 Fig. 2.29 The melting of snow is a thermodynamic process�������������������������������� 86 Fig. 2.30 Water vapor from tank receiving hot water from a paper industry������� 87 Fig. 2.31 Entropy of a solid < entropy of a liquid < entropy of a gas������������������ 88

List of Figures

Fig. 3.1 Fig. 3.2 Fig. 3.3 Fig. 3.4 Fig. 3.5 Fig. 3.6 Fig. 3.7 Fig. 3.8 Fig. 3.9 Fig. 3.10 Fig. 3.11 Fig. 3.12 Fig. 3.13 Fig. 3.14 Fig. 4.1 Fig. 4.2 Fig. 4.3 Fig. 4.4 Fig. 4.5 Fig. 4.6 Fig. 4.7 Fig. 4.8 Fig. 4.9 Fig. 4.10 Fig. 4.11 Fig. 4.12 Fig. 4.13 Fig. 4.14 Fig. 4.15 Fig. 4.16 Fig. 4.17 Fig. 4.18 Fig. 4.19 Fig. 4.20 Fig. 4.21

xxiii

Health and environment������������������������������������������������������������������������ 96 Pristine natural environment����������������������������������������������������������������� 97 Alteration of environment for human benefit��������������������������������������� 98 Urban settling with improper planning������������������������������������������������� 99 Characteristics of living beings������������������������������������������������������������� 99 Illustration showing complex arrangement of chemicals that makes an organism������������������������������������������������������������������������������ 100 Structure of a typical bacterium���������������������������������������������������������� 104 Chain of infection������������������������������������������������������������������������������� 106 A waste picker with insufficient personal protective equipment exposing herself for direct transmission of infection�������������������������� 107 Water overflowing due to accidental damage to water supply line exposing public water supply to microbial contamination���������� 108 Sylvatic disease cycle�������������������������������������������������������������������������� 119 Wildlife to domestic animal to human disease transmission�������������� 120 Vector transmitted urban/rural disease cycle�������������������������������������� 122 Paddy fields����������������������������������������������������������������������������������������� 123 Different types of interaction among the organisms��������������������������� 133 Food cycle������������������������������������������������������������������������������������������� 134 Humans in the food web��������������������������������������������������������������������� 135 Linking between biosphere and organisms����������������������������������������� 135 Photos of some captive animals���������������������������������������������������������� 136 Photos of some free animals��������������������������������������������������������������� 137 Defecation in riverbed������������������������������������������������������������������������� 140 Man washing clothes in river�������������������������������������������������������������� 140 Dead calf thrown in a riverbed during a lean season�������������������������� 141 Urban discharge into Hooghly River, near Kolkata (Calcutta), India���������������������������������������������������������������������������������� 142 Disposal of solid waste in Hooghly River, Kolkata (Calcutta), India���������������������������������������������������������������������������������� 142 Water contamination by regular human activities in urban setting�������������������������������������������������������������������������������������������������� 143 Fecal matter is being managed and diverted into a natural lake, which is being used to feed in fisheries���������������������������������������������� 143 Land preparation for agricultural activity would loosen the soil particles that would be air borne along with agrochemicals fed to it������������������������������������������������������������������������ 144 Poor road condition����������������������������������������������������������������������������� 144 Examples of industry near human settlements������������������������������������ 145 Mining������������������������������������������������������������������������������������������������� 145 Cooking����������������������������������������������������������������������������������������������� 146 Fuel combustion in vehicles���������������������������������������������������������������� 146 Waste handling/combustion���������������������������������������������������������������� 147 Material handling at construction site������������������������������������������������� 148

xxiv

Fig. 4.22 Fig. 4.23 Fig. 4.24 Fig. 4.25 Fig. 4.26 Fig. 4.27 Fig. 4.28 Fig. 4.29 Fig. 4.30 Fig. 4.31 Fig. 4.32 Fig. 4.33 Fig. 4.34 Fig. 4.35 Fig. 4.36 Fig. 4.37 Fig. 4.38 Fig. 4.39 Fig. 4.40 Fig. 5.1 Fig. 5.2 Fig. 5.3 Fig. 5.4 Fig. 5.5 Fig. 5.6 Fig. 5.7 Fig. 5.8 Fig. 5.9 Fig. 5.10 Fig. 5.11 Fig. 5.12 Fig. 5.13 Fig. 5.14 Fig. 5.15 Fig. 5.16 Fig. 5.17 Fig. 5.18 Fig. 5.19

List of Figures

Diesel generator at a construction site for electric generation������������ 148 Road sweeping������������������������������������������������������������������������������������ 149 People exposed to pollutants��������������������������������������������������������������� 150 Examples of physical, chemical, and biological characteristics of pollutants, which define their impacts on health���������������������������� 150 Classification of pollutants������������������������������������������������������������������ 153 Water pollution due to waste discarded next to stream����������������������� 155 Schematic diagram of health impact due to solid waste��������������������� 156 Cathode ray tube of television disposed on road�������������������������������� 157 View of waste dump site��������������������������������������������������������������������� 161 Chicken and cow feeding on garbage������������������������������������������������� 163 Spillage and seepage during transportation of waste�������������������������� 164 Waste segregation�������������������������������������������������������������������������������� 164 Waste coconut being dried before being sent for oil extraction���������� 165 Segregated paper and cardboard waste����������������������������������������������� 165 Waste being received at collection centers������������������������������������������ 166 Manual waste segregation������������������������������������������������������������������� 166 Waste storage�������������������������������������������������������������������������������������� 167 Leachate generation from waste dump����������������������������������������������� 167 Construction and demolition waste at the site of demolition�������������� 168 Usual forms of exposure–response relationships�������������������������������� 176 The clinical course of an ailment�������������������������������������������������������� 177 Branches of medicine�������������������������������������������������������������������������� 177 Different way of classifying medical specialties�������������������������������� 178 Stages of infectious disease���������������������������������������������������������������� 181 Categorization of diseases based on the significance of diseases������� 181 Main causes of diseases���������������������������������������������������������������������� 183 Major environmental factors that affect human health����������������������� 184 Froth formations in lake due to misuse of the common property for discharge of untreated effluent���������������������������������������� 187 Use of lakes by animals to keep them cool����������������������������������������� 188 Use of lakes for disposing solid waste������������������������������������������������ 188 Use of lakes by people to wash cloths������������������������������������������������ 189 Remains reinforcement idols of clay idols after immersing in water������������������������������������������������������������������������������������������������ 189 People washing cattle in surface water����������������������������������������������� 190 People washing vehicle in surface water�������������������������������������������� 190 Remains of worshiping material disposed in surface water body������� 191 Classification of immunity system������������������������������������������������������ 204 Schematic diagram for explaining herd immunity������������������������������ 205 Exposure to polluted air could lead to food contamination���������������� 209

List of Figures

xxv

Fig. 6.1 Land use conflict such as temporary road blockage by putting rented ceremonial tent for ceremony by a resident in front of his house and motorist trying to pass road divider are common scene in India. In theory such cases are not permitted but in practice they happen regularly���������������������������������� 222 Fig. 6.2 Photos of coastal area�������������������������������������������������������������������������� 223 Fig. 6.3 In the absence of separate space for washing a lady in poor community is washing her cloths and utensils in front of her house adjacent to road�������������������������������������������������������������� 224 Fig. 6.4 Demolition in progress with partial coverage to combat air pollution and objects falling on ground—another example for theory and practice������������������������������������������������������������������������ 229 Fig. 6.5 Impact of pollution on human health�������������������������������������������������� 229 Fig. 6.6 Death of pollinators due to pollution may reduce food production������������������������������������������������������������������������������������������� 231 Fig. 6.7 Overflow of manholes and drains due to poor maintenance that leads to overflow of sewage with pathogens and toxins can become breeding ground for vectors or remission of pathogen by contact������������������������������������������������������������������������ 233 Fig. 6.8 Major factors affecting vulnerability�������������������������������������������������� 234 Fig. 6.9 Impact of climate change on health���������������������������������������������������� 234 Fig. 6.10 Impact of health due to flood�������������������������������������������������������������� 235 Fig. 6.11 Impacts due to draught������������������������������������������������������������������������ 235 Fig. 6.12 Abandoned construction material and waste at a construction site���������������������������������������������������������������������������������� 237 Fig. 6.13 A cow let to feed on waste������������������������������������������������������������������ 238 Fig. 6.14 Haphazard disposal of poultry litter���������������������������������������������������� 240 Fig. 6.15 A vegetable vendor next to waste in a vegetable market—a situation that can lead to food contamination������������������������������������� 241 Fig. 6.16 Waste dumped adjacent to mango and coconut trees from which toxins may enter fruits�������������������������������������������������������������� 242 Fig. 6.17 A drinking water bore well next to usual waste throwing area—a situation that can lead to water contamination���������������������� 242 Fig. 7.1 Photograph of people working in an informal setup��������������������������� 259 Fig. 7.2 Photograph of people working in a formal setup but with weak enforcement������������������������������������������������������������������������������� 260 Fig. 7.3 Poverty often pushes people to unsafe practices��������������������������������� 260 Fig. 7.4 Some of the risks in the work environment���������������������������������������� 269 Fig. 7.5 Radiation and safety���������������������������������������������������������������������������� 270 Fig. 7.6 Methods to reduce effects of noise����������������������������������������������������� 270 Fig. 7.7 Some of occupational hazards due to biological agents��������������������� 271 Fig. 7.8 Hierarchy of hazard prevention and control��������������������������������������� 273

xxvi

List of Figures

Fig. 7.9 Elimination of tree for safety of workers and road users�������������������� 274 Fig. 7.10 Substation of jet bridge to bus in airports for boarding passengers engineering control����������������������������������������������������������� 274 Fig. 7.11 Engineering control and administrative control in airport wherein strict safety producers are followed along with proper infrastructure and machineries������������������������������������������������ 275 Fig. 7.12 Systematic arrangement of boarding stairs����������������������������������������� 276 Fig. 7.13 Safe parking of aircraft by administrative control such as training, legislation and policy������������������������������������������������������� 276 Fig. 7.14 Floor signage��������������������������������������������������������������������������������������� 277 Fig. 7.15 Use of personnel protective equipment in an airport�������������������������� 278 Fig. 7.16 Unsafe workplace�������������������������������������������������������������������������������� 279 Fig. 7.17 Maintenance of a railway track����������������������������������������������������������� 279 Fig. 7.18 Vegetable vendors on roads����������������������������������������������������������������� 280 Fig. 7.19 Trash pickers��������������������������������������������������������������������������������������� 281

List of Tables

Table 1.1 Table 1.2 Table 1.3 Table 1.4 Table 1.5 Table 1.6

Common terms used in general chemistry������������������������������������������� 5 Examples of solutions�������������������������������������������������������������������������� 7 Comparison of organic compound and inorganic compound��������������� 7 Main classes of organic compounds��������������������������������������������������� 28 Examples of colloidal suspension������������������������������������������������������ 33 Properties of protons, neutrons, and electrons����������������������������������� 44

Table 2.1 Table 2.2 Table 2.3 Table 2.4 Table 2.5 Table 2.6

Frequently used terms in physics������������������������������������������������������� 51 Common terms used in dynamics������������������������������������������������������ 53 Common terms used in solid mechanics�������������������������������������������� 56 Common terms used in fluid mechanics��������������������������������������������� 58 Density of blood and its components������������������������������������������������� 60 Length, velocity, and time scales of environmental fluid processes and systems������������������������������������������������������������������������ 65 Application of fluid mechanics in environmental science������������������ 66 Definition of common terms with respect to lens������������������������������� 73 Definition of common terms with respect to mirror��������������������������� 78 Important wave terminologies������������������������������������������������������������ 79 Common terms used in electrical and electronics sciences���������������� 81 Common terms used in thermal physics��������������������������������������������� 84 Relationships of different temperature scales������������������������������������� 85

Table 2.7 Table 2.8 Table 2.9 Table 2.10 Table 2.11 Table 2.12 Table 2.13 Table 3.1 Table 3.2 Table 3.3 Table 3.4 Table 3.5 Table 3.6

Movements of substance into and out of the cell����������������������������� 102 Description of domains and kingdoms of living organisms������������� 103 Requirements of complex multicellular animals������������������������������ 103 Description of bacterium structure��������������������������������������������������� 105 Major types of shapes and groups of bacteria���������������������������������� 106 Examples of intervention to reduce or eliminate infectious and parasitic diseases in human beings�������������������������������������������� 109 Table 3.7 Disease classification prepared by the World Organisation for Animal Health for the year 2018������������������������������������������������ 114 xxvii

xxviii

List of Tables

Table 3.8 Some of the common zoonosis, main reservoir of causative agents, and usual mode of transmission to humans�������������������������� 118 Table 3.9 Some of the common vector-borne diseases������������������������������������ 121 Table 3.10 Hierarchy of controlling ailment due to environmental factors������� 125 Table 4.1 Table 4.2 Table 4.3 Table 4.4

Types of environmental pollution����������������������������������������������������� 139 Examples of secondary pollutants���������������������������������������������������� 153 Examples of solid waste categorization and health hazard�������������� 158 Some of the major disasters due to improper waste disposal����������� 162

Table 5.1 Table 5.2 Table 5.3 Table 5.4 Table 5.5 Table 5.6 Table 5.7

Major toxic causative agent�������������������������������������������������������������� 180 Examples of important terms used in pathology������������������������������ 182 Example of culture and impact on the environment and health������� 192 Some sources of nutrients����������������������������������������������������������������� 206 Some sources of vitamins����������������������������������������������������������������� 207 Sources of common minerals����������������������������������������������������������� 208 Types of adulteration������������������������������������������������������������������������ 208

Table 6.1 Major air pollution episodes������������������������������������������������������������� 228 Table 6.2 Some of the published food contamination studies�������������������������� 230 Table 6.3 Categories of health-care waste�������������������������������������������������������� 243 Table 7.1 Common possible risks in some of the workplaces������������������������� 262 Table 7.2 Hazard identification and risk assessment for water sample collection and field monitoring��������������������������������������������������������� 265 Table 7.3 Sample OCP for general safety measures���������������������������������������� 282 Table 7.4 Sample OCP for safe handling of chemicals������������������������������������ 283

List of Boxes

Box 1.1 Box 1.2

Radiation and Importance to Health�������������������������������������������������� 44 Radioactive Waste Case Study����������������������������������������������������������� 45

Box 3.1 Box 3.2

Microorganism and Infection����������������������������������������������������������� 104 Cancer Express��������������������������������������������������������������������������������� 123

Box 4.1 Box 4.2

Plastic Pollution of Ocean���������������������������������������������������������������� 141 Case Studies������������������������������������������������������������������������������������� 156

Box 5.1 Toxic Exposures at Workplace��������������������������������������������������������� 180 Box 5.2 Drinking Water and Skin Health������������������������������������������������������ 193 Box 5.3 Fluoride and Fluorosis: Case Studies����������������������������������������������� 196 Box 5.4 Pollution and Neurological Disease������������������������������������������������� 198 Box 5.5 Pesticide in Modern Agriculture and Health������������������������������������ 199 Box 5.6 Forest Fire and Lung������������������������������������������������������������������������ 200 Box 5.7 Industrial Gas Accident and Pulmonary Health������������������������������� 200 Box 5.8 Itai-Itai���������������������������������������������������������������������������������������������� 201 Box 5.9 Cross Contamination of Water System and Gastroenteritis��������������������������������������������������������������������������� 202 Box 5.10 Armadale Case Study����������������������������������������������������������������������� 203 Box 5.11 Contamination of Food at Home������������������������������������������������������ 205 Box 5.12 Nutrition Versus Poison������������������������������������������������������������������� 206 Box 6.1 Box 6.2

Thoothukudi Massacre��������������������������������������������������������������������� 231 Disability Adjusted Life Years explained����������������������������������������� 232

xxix

Part I

Introduction to Basic Sciences

Chapter 1

Fundamentals of Chemistry for Environmental and Medical Professionals Abstract Accurate understanding of the human health and environment needs strong foundation of chemistry. The continuous chemical changes in the environment have significant influences on human health. Chemistry is a specialization of science that typically deals with the composition, structure, properties, as well as change of matters. All biotic and abiotic components of the environment are made up of entities that qualify as chemicals, for example, the proteins of animals and plants, soil on which we walk, rock on which we climb, diamond in our rings, cloth we wear, water we drink, air we breathe, and the food we eat. In order to save the environment, the environmental professionals, especially the advisers in the government, should have sound knowledge of chemistry. Many of the decisions taken depend on the environmental monitoring. Erroneous sampling, preservation, and analysis would lead to erroneous decisions that directly affect public health. Further engineering solutions to combat pollution economically need understanding of chemistry besides formulation of medicine to an ailment. This chapter discusses the fundamentals of chemistry, which is often the basis of environment and medical science.

1.1  Introduction Chemistry is a specialization of science that deals with the composition, structure, properties, as well as change of matters. The term “chemical substance” (Fig. 1.1) refers to any form of matter that has constant chemical composition of its constituent such that its physical properties are determinable. All the matter on earth including human body is made up of one or the other chemicals or combination of chemicals. Changes in the chemical compositions beyond a certain limit in the environment may affect the health of a person who interacts with it. Pollution does not honor international political boundaries, and so does the epithelial tissue that acts as the boundary between our body and the surrounding environment. Environmental chemistry draws on a range of concepts from chemistry including understanding solutions, units, sampling, chemical reactions and equations, and analytical techniques (Williams 2001). Chemistry has many applications in medical and environmental sciences. Boron compounds now have applications in Medicinal Chemistry (Ali et al. 2020). Outdoor © Springer Nature Switzerland AG 2021 R. Chandrappa, D. B. Das, Environmental Health - Theory and Practice, https://doi.org/10.1007/978-3-030-64480-2_1

3

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1  Fundamentals of Chemistry for Environmental and Medical Professionals

Fig. 1.1  Chemical substance refers to any form of matter that has constant chemical composition of its constituent entities

environment is an oxidant-driven system compared to indoor environments where gas-phase oxidant concentrations are relatively low (Abbatt and Wang 2020). The changes in the environment could be slow due to release of pollutants or sudden as in case of gas leakage or bomb blast. Furthermore, the earth is a continuous reactor where millions of reactions happen at a time and so is our body where at least a few hundreds of reactions keep happening without our knowledge. We do not have the complete control on the biochemical reactions in our body that are directly linked to our environment. With better understanding of chemistry, the concerned experts on both environmental health and medical sciences can provide well-­ informed advice to decision makers on how to take precautionary measures or corrective actions to safeguard the public health to the maximum extent possible.

1.2  General Chemistry Chemicals are not just substances that are present in chemistry laboratory or warehouse of a chemical industry. Chemical substances refer to any forms of matters that have constant chemical compositions of their constituent entities (Fig. 1.1). All biotic and abiotic components of the environment are made up of entities that qualify as chemicals, for example, various proteins of animals and plants, soil on which we walk, rock on which we climb, diamond in our rings, cloths we wear, water we drink, air we breathe, and the food we consume. The common terms used in general chemistry are given in Table 1.1.

1.2  General Chemistry

5

Table 1.1  Common terms used in general chemistry Sl. No. Term 1. Atom 2. 3. 4. 5. 6. 7.

8. 9.

10.

11. 12.

13.

14. 15.

16. 17. 18. 19. 20.

Description Smallest component unit of matter that has the same properties of a chemical element Protons Positively charged particles of an atom Neutrons Neutral particle of an atom Nucleus of an atom Dense region at the center of atom comprising of protons and neutrons Electrons Negatively charged particles of an atom that revolve around nucleus of an atom in different orbits (or shells) Element A chemical element is a chemical substance containing of atoms having the same atomic number (IUPAC 2015a) Compound An entity comprising of two or more different atoms connected with chemical bonds, with a fixed ratio among constituent elements; the ratio of each element is normally expressed by its chemical formula Molecule Smallest particles of an element or compound that possess all the properties of that substance and are made up of one or many atoms Atomic mass unit In 1961, a universally accepted atomic mass unit of carbon-12 (AMU) (represented as 12C) isotopes was chosen as the standard reference for measuring atomic masses; according to this convention, atomic mass of a single 12C atom is 12 atomic mass unit (AMU) Atomic number Atomic number (Z) is the number of protons in the nucleus of an atom of the element; each atom of an element will have the same number of protons; neutral atoms will have the same number of electrons as well as protons Molecular weight The molecular weight is the mass of one mole of a substance usually expressed as grams per mole Mole (gram Quantity of any chemical material that comprises of as many molecular weight) elementary entities (atoms/molecules/ions/electrons) as there are atoms in 12 grams of pure carbon-12 (12C) Ions Any atom that gains or loses electrons will become electrically charged; thus, any charged atom or group of atoms is called ions; ions are expressed as a superscript to the symbol (e.g., Na+1 or cl−1) Atomic mass Sum of the numbers of protons as well as neutrons number Isotopes Variants of chemical elements that have the same atomic number but different mass number; each isotope of an element has the same atomic number but a different mass number (A), which is the sum of the numbers of protons as well as neutrons Anion Negatively charged ions Cation Positively charged ions Radical A group of atoms with a charge that goes through a reaction without change is called a radical Chemical bond Force that holds atoms together in a chemical compound Covalent bond In covalent bonding, electrons are shared between atoms in a molecule or polyatomic ion (continued)

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1  Fundamentals of Chemistry for Environmental and Medical Professionals

Table 1.1 (continued) Sl. No. Term 21. Ionic bond 22.

23. 24. 25. 26. 27.

28.

Description In ionic bonding, positively as well as negatively charged ions are connected together by electrostatic forces Chemical symbol Symbol is a code for a chemical element usually derived from the name of the element; use of symbol serves two purpose—It reveals (a) the elements in it, and (b) the ratio of each element; examples of symbol Chemical formula A mathematical relationship between elements that builds a compound; examples of chemical formulae Valence (or valance Number of electrons present in the outermost orbit (or shell) of an number) atom Valency Measure of an atom’s combining power with other atoms when it forms molecules; examples of valence Structural formula Graphical representation of the arrangement of atoms in a chemical substance Each mole will have approximately the same number of elementary Avogadro’s entities, which is called Avogadro’s number or Avogadro’s constant number (symbols: L, NA), which has a value 6.022140857 × 1023 mol−1 (Mohr (Avogadro’s constant) et al. 2008; IUPAC 1992, 1996) Stoichiometry Stoichiometry is a collective term for the quantitative relationship between the numbers of atoms/molecules/ions, the masses, and the numbers of moles

The matter is made up of pure and impure substances. Pure substances are made up of only one type of atom or molecule whereas the impure substances contain more than a single type of atom or molecule. As of 2019, there are 118 elements that have been identified, of which 98 occur naturally and the remaining 20 being synthetic elements. Actual mass of hydrogen is found to be 1.673 × 10−24  g, which is extremely small. It is found to be easy to compare the masses of different atoms with some reference atom. Moles are used in chemical/environmental engineering process by using concept of molar flow rate, which is the number of moles of a solution that passes a fixed point per unit time. Molar flow rates are useful because using moles instead of mass allows writing material balances in terms of reaction conversion as well as stoichiometry. The molecular weight of a compound is the summation of the atomic weights of the atoms that form a molecule of the compound; for example, atomic oxygen (O) has an atomic weight of 16 and hence molecular oxygen (O2) has a molecular weight of 32. A gram-mole (g-mole or mol in SI units) of a species is the quantity of that species whose mass in grams is numerically equal to its molecular weight. Hence, one mole of oxygen is 32 g. Figure 1.2 shows a typical reactor in an industry. Engineers are often interested in reactions between large quantities of chemicals. Hence, kg-moles, lb-moles, and

1.2  General Chemistry

7

Table 1.2  Examples of solutions Sl. No. 1.

Type of solution Solid solutions

2.

Liquid solutions

3.

Gaseous solutions

Solute Solid Liquid Gas Solid Liquid Gas Solid Liquid Gas

Solvent Solid Solid Solid Liquid Liquid Liquid Gas Gas Gas

Example Alloy Hydrated crystals such as blue vitriol Gases adsorbed over the surface of metals Sea water Dilute sulfuric acid Aerated drinks Iodine in air Water vapor in air Air

Table 1.3  Comparison of organic compound and inorganic compound Description Type of bonding Molecular size Water solubility Solubility in organic solvents Classes of compounds Structural formulae

Inorganic compound Ionic Small Soluble Insoluble Acid, base, or salt Unimportant

Organic compound Covalent Large Insoluble Soluble Many (functional groups) Very important

ton-moles are used in engineering calculations. For example, carbon monoxide has a molecular weight of 28; hence, 1 mol of CO contains 28 g, 1 lb-mole of CO contains 28 lbm, 1 ton-mole of CO contains 28 tons. When a chemical is released into the environment, it becomes distributed among the four major environmental compartments: (1) air, (2) water, (3) soil, and (4) flora and fauna, that is, living organisms. Figure 1.3 shows a waste dump and stack from which emissions occur. The distribution of chemicals in the environment is governed by physical processes such as (1) sedimentation, (2) adsorption, and (3) volatilization, and the chemicals can then be degraded by chemical and/or biological processes. Stoichiometric equations are often used by environmental professionals for calculating the amount of emissions. One of the classic examples where the “mole” is used is while calculating the quantity of pollutants emitted from combustion.

S + O2 → SO2



One mole of Sulfur + one mole of Oxygen → One mole of Sulfur Dioxide



16 g of Sulfur + 16 g of Oxygen → 32 g of Sulfur Dioxide In other words, 1 g of S reacts with 1 g of O2 to produce 2 g of SO2.

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1  Fundamentals of Chemistry for Environmental and Medical Professionals

Fig. 1.2  A typical reactor in an industry

Suppose that coal fed to a boiler of a thermal power plant has 4% of sulfur content. Each ton of the coal will have 4  kg of sulfur and, therefore, 8  kg of sulfur dioxide is produced. Reactions wherein the products recombine/disintegrate to form chemicals from which they are originated are called reversible reactions. If the products remain unaltered, then they are called irreversible reactions. Reactions happen in nature every day and almost every place: in atmosphere, below the earth, inside water bodies, within our bodies, etc. The environmental engineers are concerned with undesirable consequence like the one shown in Fig.  1.4, wherein presence of numerous chemicals in solid waste dumpsite has resulted in the formation of complex chemicals in the form of leachate. Chemical processes in the environment usually occur in water or the atmosphere. The chemical reactions in the environment follow one of the following four reactions: 1. 2. 3. 4.

Oxidation. Reduction. Hydrolysis. Photolysis.

The oxidation that occurs during a combustion process (Fig. 1.5) leaves behind reduced substances in the form of ash or that are released to the atmosphere r­ esulting in pollution. Combustion of fuel in vehicles, thermal power plants, and waste incineration occur due to oxidation/reduction reactions that liberate energy. Oxidation reaction involves the loss of an electron by a molecule, atom, or ion. It is often the reaction with oxygen. Reduction involves gain of an electron by a molecule, atom, or ion. It is often the reaction with hydrogen. Hydrolysis involves splitting of a compound into other compounds by reaction with water. Photolysis is decomposition or separation of molecules by the action of light.

1.2  General Chemistry Fig. 1.3  Waste dump and stack from which emissions occur. Stoichiometric equations are often used by environmental professionals for calculating emissions from such waste dump and stack

Fig. 1.4  Leachates formed due to reaction among the chemicals in the solid waste

9

10

1  Fundamentals of Chemistry for Environmental and Medical Professionals

Fig. 1.5  Oxidation occurs during combustion

Oxidation is of great interest to environmental professionals as the phenomenon can be used to treat wastewater by transferring oxygen from air to wastewater by aerating wastewater (Fig. 1.6.). Biological mechanisms in living organisms involve oxidation, reduction, hydrolysis, and conjugation to degrade chemicals. Conjugation is joining of two or more chemical compounds. Our body depends on chemical reactions throughout our life. The digestion process involves chemical reaction for breaking down into smaller molecules. Chemical reactions obey two fundamental laws: 1. Law of conservation of mass (matter can neither be created nor destroyed). 2. Law of conservation of energy (energy can neither be created nor destroyed).

Fig. 1.6  Aeration of wastewater

1.2  General Chemistry

11

Matter can neither be created nor destroyed. Hence, the number of each type of atom on both sides of a chemical reaction should be the same. Balancing chemical reactions is the process of making certain the conservation of matter. As per IUPAC (2015b), the “oxidation state” of an atom in a molecule is the number of valence electrons it has gained or lost. Metals and non-metals play important roles in human health and so do acids as well as bases. The distinction between metals and non-metals is by no means clear (Cracolice and Peters 2011), and some elements that lack a preponderance of either non-metallic or metallic properties are grouped as metalloids. Metals are diverse substances, with different properties and characteristics. Metals in the environment vary and distribution of metals is governed by the properties of the metal and influences of environmental factors. Out of the 92 naturally occurring elements, following metals and metalloids (intermediate between metals and non-metals) are potentially toxic to humans: 1. Aluminum. 2. Antimony. 3. Arsenic. 4. Barium. 5. Beryllium. 6. Bismuth. 7. Boron. 8. Cadmium. 9. Cesium. 10. Chromium. 11. Cobalt. 12. Copper. 13. Gold. 14. Lead. 15. Lithium. 16. Manganese. 17. Mercury. 18. Molybdenum. 19. Nickel. 20. Palladium. 21. Platinum. 22. Selenium. 23. Silver. 24. Strontium. 25. Tellurium. 26. Tin. 27. Titanium. 28. Tungsten. 29. Vanadium.

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1  Fundamentals of Chemistry for Environmental and Medical Professionals

Heavy metals are the generic term for metallic elements with an atomic weight higher than 40.04 (Ming-Ho 2005). Heavy metals in the environment can affect human health. Heavy metals in the environment reach human body through atmosphere, soil, water, and foods. Although toxicity to human health depends on concentration of toxic substance, chronic exposure to heavy metals and metalloids at relatively low levels can cause adverse effects. A chemical with at least one hydrogen atom that can dissociate to form an anion and hydrogen ion (H+) in aqueous solution is called as an acid. A chemical that produces one or more hydroxide ions (OH−) and a cation when dissolved in aqueous solution is called a base. An acid in which the dissociable H+ ion is attached to an oxygen atom of a polyatomic anion is called oxoacids or oxyacids. The pH scale provides an easy way of expressing the hydrogen ion (H+) concentration of a solution. pH is defined as negative of the logarithm to base 10 of the concentration of hydrogen ions in moles per liter. pH = − log10 H + 





Where. [H+] = hydrogen ion concentration in moles per liter. In the absence of foreign materials, the hydrogen ion concentration is 1.0 × 10−7 moles in pure water at 25 °C, and hence the pH of pure liquid water is 7 as per the following calculation.

Fig. 1.7  pH values of various water and wastewater, and discharge standards for treated wastewater

1 M NaOH

1 4

Dairy Wastewater

Sewage

Pure Water

Rain Water

Electroplating Wastewater Acid Rain

[H+]

10-0

10

1 M HCl

10-7

1

-14

pH

Discharge Standard

7

13

1.2  General Chemistry



pH = − log10 1.0 × 10 −7  = 7



pH values of various water and wastewater, and discharge standards for treated wastewater are shown in Fig. 1.7. The standards of 6–9 is usually practiced even though standards of 6.5–8.5 are sometimes prescribed by some countries as it is not practically possible to bring down the pH value to exactly 7. Reaction between acid and base will result in salts. In other words, a salt is the product of an acid–base reaction. A salt is an ionic compound having some cation other than hydrogen as well as some anion other than hydroxide as well as oxide.

1.2.1  The Gas Laws The gas laws are important to the environmental professionals as we live and breathe in air that has direct impact on our health. The numerous chemical molecules within the environment and our body interact as per natural phenomena explained by the gas laws, briefly explained in subsequent sections. 1.2.1.1  Boyle’s Law Boyle’s law states that the volume of an ideal gas is inversely proportional to its pressure at a constant temperature (Fig. 1.8). The law is written as:

1 kg 1 kg 1 kg

T = Xo C

Fig. 1.8  Schematic depiction of Boyle’s law

T = Xo C

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1  Fundamentals of Chemistry for Environmental and Medical Professionals

Pα



1 V

Where P = pressure of gas. V = volume of gas. When we inhale air, muscles increase the size of chest cavity and expand the lung that increases their volume thereby reducing pressure inside the lungs. Damage to the lungs due to infection and pollution would affect pulmonary health of the affected person. 1.2.1.2  Charles’ Law Charles’ law states that the volume of gas is directly proportional to the absolute temperature (Fig. 1.9). Mathematically the law is written as: Vα T



Where V is the volume of a gas and T is the absolute temperature (details of absolute temperature is discussed in Chap. 2). Increase in volume of air due to the warming of air in the respiratory system can be explained in the light of Charles’s law. 1.2.1.3  Pressure Law Pressure law states that for a fixed mass and constant volume of an ideal gas, the pressure is directly proportional to absolute temperature (Fig. 1.10). 1 kg 1 kg

T = 2Xo C

Fig. 1.9  Schematic depiction of Charles’ law

T = Xo C

1.2  General Chemistry

15

Fig. 1.10 Pictorial depiction of pressure law

1 kg 1 kg 1 kg

1 kg

T = 2Xo C

Mathematically it implies that: Pα T



Where P is the pressure and T is the absolute temperature. 1.2.1.4  Generalized Gas Law Charles’ and Boyle’s laws can be combined to get the following equation:



PV = β T orV = β

T P

Where β = a constant that is proportional to the weight of the gas. P = pressure of gas. V = volume of gas. T = temperature of the gas. 1.2.1.5  Gay-Lussac’s Law of Combining Volumes Gay-Lussac’s law of combining volumes states that the ratio among the volumes of the reactant gases as well as the gaseous products can be expressed as whole numbers.

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1.2.1.6  Henry’s Law Henry’s law states that the quantity of the dissolved gas in liquid is proportional to its partial pressure above the liquid. Mathematically, Henry’s law is written as: Cequil = α Pgas





Where Cequil = the concentration of gas dissolved in the liquid at equilibrium. Pgas = the partial pressure of the gas above the liquid. α = Henry’s law constant for the gas at the given temperature. 1.2.1.7  Graham’s Law Graham’s law states that the rates of diffusion of gases are inversely proportional to the square roots of their densities. 1.2.1.8  Dalton’s Law of Partial Pressure Dalton’s law of partial pressure states that the total pressure exerted by mixture of non-reacting gases is equal to the sum of the partial pressures of the individual gases (Fig. 1.11). Mathematically, Ptotal = Pgas1 + Pgas 2 + Pgas3 +…+ Pgasi





Where Ptotal is the pressure exerted by all gases on a body and P1, P2, P3,…Pi are the partial pressure exerted by each gas.

Gas 1

Pgas1 = 1 atm

+

Gas 2

Pgas1 = 1 atm

+

Gas 3

Pgas1 = 1 atm

Fig. 1.11  Pictorial depiction of Dalton’s law of partial pressure

→

Gas 1, 2, 3

Pgas1,2,3 = 3 atm

1.2  General Chemistry

17

1.2.1.9  Avogadro’s Law Avogadro’s law states that under the same conditions of pressure and temperature, equal volumes of different gases have an equal number of molecules. Mathematically, this law is written as: V1 V2 = n1 n2





Where n1 = number of molecules in gas with volume V1. n2 = number of molecules in gas with volume V2 1.2.1.10  Combined Gas Laws The combined gas law is obtained by combining the relationship between the pressure, volume, and temperature for a fixed quantity of gas, written as: p1V1 p2V2 = T1 T2





1.2.1.11  Ideal Gas Law By the addition of Avogadro’s law, the combined gas law develops into the ideal gas law: pV = nRT

Where

p = pressure of gas. V = volume of gas. n = the number of moles. R = the universal gas constant (value of 0.08206 [atm∙ L/mol∙K]). T = absolute temperature (K). An equivalent formulation of this law is: Where p = the pressure of gas.

pV = kNT

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V = the volume of gas. N = the number of gas molecules. k = the Boltzmann constant (1.381 × 10−23 J·K−1 in SI units). T = the absolute temperature. Hence, the volume of 1 mol of an ideal gas at standard temperature and pressure (0 °C and 1 atm) can be calculated as follows (Fig. 1.12):



atm ⋅ L   0.08206 ( 273.15K )  nRT mol ⋅ K  V= = 22.41 L = (1.000mol )  1.000atm P

1.2.2  Solutions Air and water always exist as mixtures in nature. Homogeneous mixtures of two or more substances are termed as solutions. A solution can be in gas, liquid, or solid form. Table 1.2 illustrates typical examples of solutions. Solutions are of great interest to the environmental professionals as the water in nature exists as solution of many substances dissolved in it. The air we breathe from the atmosphere has many gases in it. Most of the hazardous solid waste also usually occurs as a solution. Polluted air and water need treatment to bring down the pollutants to acceptable limits. Solution is made up of solutes and solvents. A solute is a substance dissolved in another substance, called as a solvent. Each solution can have many solutes. Wastewater will have many pollutants that qualify as solutes, and its separation from waste stream is done based on the property of pollutants. Many conventional technologies in the manufacturing facility are used to treat waste streams as well. For example, distillation separates mixture or solution by use of variation in volatility. Crystallization processes make use of variation in solubility.

1.3  Physical Chemistry Physical chemistry specialization of chemistry is concerned with particulate, atomic, macroscopic, as well as subatomic phenomena in terms of laws/concepts of physics in chemical systems. This branch of chemistry applies the principles, practices, as well as concepts of physics such as force, energy, motion, time, thermodynamics, statistical mechanics, quantum chemistry, dynamics, and equilibrium. Physical forces within and outside molecules within our environment and our body have an impact on health. While some forces are beyond our control, others

1.3  Physical Chemistry

He

19

O2

NH 3

CH4

V = 22.41 L

V = 22.41 L

V = 22.41 L

V = 22.41 L

P = 1 atm

P = 1 atm

P = 1 atm

P = 1 atm

Fig. 1.12  The volume of 1 mol of an ideal gas at standard temperature and pressure is 22.41 L, the standard molar volume

can be manipulated to safeguard human health by changing reaction kinetics and thermodynamics.

1.3.1  Thermochemical Reactions Reactions showing changes in both matter and energy are called thermochemical reactions. Reactions can be exothermic or endothermic. Exothermic reactions are those that releases heat (e.g., combustion of fuel generating mixture of gases). Endothermic reactions are those that absorb heat (e.g., dissolving table salt in water). Chemical reactions are spontaneous when they continue on their own. Reactions may need initiation with a spark and/or other source of energy. Photosynthesis and biodegradation are examples of exothermic reaction. Most spontaneous reactions are also exothermic, which produce heat and/or other forms of energy, as in the case of fire. However, a few reactions are endothermic, which consume energy from their environment. Physical states of reactants/products are sometimes indicated in chemical equations, as shown in the above equations. Notations s, l, g, and aq in such equations stand for solid, liquid, gas, and aqueous solution (dissolved in water), respectively. Examples:

C ( s ) + O2 ( g ) → CO2 ( g ) + 94 kcal



2H 2 O ( g ) + 116 kcal → 2H 2 ( g ) + O2 ( g )



Intermolecular forces also cause another phenomenon called capillary action, which is the tendency of a polar liquid to ascend against gravity into a capillary tube (small-diameter tube).

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Example of thermochemical reaction within human body includes formation of glucose from starch, fats, proteins, and other sugars. Energy consumption per unit of body weight decreases with size as the rate of heat loss to the environment depends largely on the surface area of an organism in a given environment. Thus, the interrelationship between environment and human body is a factor that determines health of humans due to thermochemical reaction.

1.3.2  Osmosis Osmosis is a property observed with respect to solutions with semipermeable membrane. Osmosis is the net flow of solvent through a semipermeable membrane where the solvent flows from lower concentration of solute to the higher concentration. Cellular health is the cornerstone of health for humans. The cell membrane permits only water and very small molecules to pass through it. Osmosis plays a major role in the gastrointestinal system of the kidneys to upkeep the health of a person. The osmotic pressure is the pressure difference between the two sides of a semipermeable membrane that separates solution with different concentrations. Osmosis is one of the reasons for the intracellular movement of body fluids within our body that has direct interrelation with the environment. Reverse osmosis (Fig. 1.13) is a process by which the solvent flows in the reverse direction, through a porous membrane, to that of natural osmosis. Fig. 1.13  A typical reverse osmosis installation

1.3  Physical Chemistry

21

The major desalination processes around the world use reverse osmosis for more than half of the installed capacity (Zhou and Tol 2005; Veerapaneni et al. 2007).

1.3.3  Dialysis Some specialized membranes are slightly more permeable to solutes and use a related process known as dialysis (a process that uses a semipermeable membrane with pores big enough to allow small solute molecules as well as solvent molecules to pass through but not large solute molecules). Failure of kidneys would compel patients to use dialysis wherein dialysis machine blood is pumped next to a membrane with dialysis fluid on the other side so that the water in the blood, and small molecules of waste, move across the membrane into the dialysis fluid.

1.3.4  Electrochemistry Electrochemistry is a specialization of physical chemistry that is concerned with the relationship between electricity and chemical reactions. In oxidation–reduction (redox) reactions, electrons are transferred from one reductant to the oxidant. This transfer of electrons gives a means for changing electrical energy to chemical energy or vice versa. The brain is an electrochemical machine and the neuron is the basic working unit of the brain. Many neurological diseases are linked to neurotoxicity arising from exposure to toxic substances in the environment. The corrosion process involves oxidation and reduction reaction (Figs.  1.14 and 1.15).

1.4  Catalytic Chemistry A catalyst is a substance that influences the rate of chemical reaction by decreasing its activation energy. Quantity of catalyst remains the same before as well as after the chemical reaction. Catalysts influence a chemical reaction by changing its mechanism, as expressed below. Reaction without catalyst: A + B = AB

Reaction with catalyst:

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Fig. 1.14  The shiny greenish surface of the statue is formed by corrosion of the copper of the statue, which forms a thin layer of an insoluble compound that contains copper, sulfate, and hydroxide ions



A + C = AC ( transient product )



AC + B = AB + C



Where A and B are reactants, C is a catalyst, AB is a product, and AC is a transient product. Catalysis reactions could be homogeneous (catalysts and reactants are in the same phase) or heterogeneous (catalysts and reactants are in different phases). Environmental professionals usually use heterogeneous catalysis for air/water pollution control. Our health is controlled by enzymes produced within our body, which acts as a catalyst to an array of biochemical reactions that has direct relation with outside environment.

1.4.1  Chemical Kinetics Chemical kinetics is the study of reaction rates (the changes in concentrations of reactants as well as products with time). Exposure to toxic substances of the environment has direct relation to the chemical kinetics and metabolism within the human body.

1.4  Catalytic Chemistry

23

Fig. 1.15  The corrosion process involves redox reaction in which metallic iron is converted to reddish-brown Fe(OH)3

The same reactants can produce different products under different conditions. Factors that influence the rate of a chemical reaction include the concentration and temperature of reactants, the solvent, their dispersion as well as physical state of reactants, and the presence of a catalyst. Dilute sulfuric acid and ethanol are converted to diethyl ether at a temperature of around 100 °C whereas at 180 °C, ethylene is formed as the major product. The reaction rates normally increase as the concentration of the reactants enhances. The phase and surface area play major role in a chemical reaction. The reaction rate in a single homogeneous solution depends on concentration and temperature. If the reaction is heterogeneous, rate of reaction depends on the surface area of the more condensed phase. Consider a reaction with the general equation:

aA + bB → cC + dD The rate of reaction can be expressed as Rate of reaction = k [ A ] [ B] m



n



Where k is rate constant; m and n are reaction order to be derived from experimental measurement. The overall order of reaction is the sum of all the exponents (i.e., m + n).

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1.4.2  Adsorption Adsorption is the process in which molecules/ions in one phase tend to attach as well as concentrate on the surface of another phase. The opposite process is called desorption. The adsorbed material is called adsorbate. The adsorbing substance is called adsorbent. Adsorption is an exothermic process, whereas desorption is ­endothermic; for this reason, heat must be applied to separate the adsorbate from the adsorbent. Activated carbon, silica gel, alumina, as well as zeolites (molecular sieves) are used widely as adsorbents in pollution control (Chandrappa and Kulshrestha 2015). Adsorption process is used both in air pollution control and water/wastewater treatment to remove various components. Adsorbents are also used in permeable reactive barrier wherein polluted groundwater is made to flow through a barrier of adsorbent or reactive substance for decontaminating the polluted groundwater (Santisukkasaem and Das 2019). Adsorption of toxic substance on human body from environment has direct link to human health.

1.5  Inorganic Chemistry Inorganic chemistry is a specialization of chemistry that covers the synthesis and behavior of inorganic and organometallic compounds. This specialization of chemistry is concerned with all chemical compounds except the myriad of organic compounds (carbon-based compounds, usually containing C–H bonds, are dealt with in organic chemistry). Organic and inorganic chemistry overlap especially in the sub-specialization of organometallic chemistry. Environmental professionals often come across inorganic chemistry (which overlaps with other branches of chemistry) while dealing with pollutants in the environment and its effect on living and non-living components of environment. Fig. 1.16  Structure of carbon atom

1.6  Organic Chemistry

25

Fig. 1.17  Arrangement of atoms in methane Hydrogen

Hydrogen

Carbon

Hydrogen

Hydrogen

Human health risks due to exposure to chemicals include inorganic chemicals, some of which are potential toxic substances.

1.6  Organic Chemistry Carbon is one of the most copious elements in our world and it is part of all living organisms. Covalent compounds containing predominantly carbon as well as hydrogen are called organic compounds. Comparisons of organic and inorganic compounds are given in Table 1.3. Carbon has six electrons distributed with two electrons on the small orbit closest to the nucleus, and the four electrons in the orbit further away (Fig. 1.16). The outer orbit has enough space for up to eight electrons. Hence, carbon will bond up to four times with other atoms, until it reaches eight electrons in its outer ring. Carbon’s ability to form four bonds (Fig. 1.17) gives it a remarkable amount of flexibility. It can exist in a simple state, such as carbon dioxide, in long chains such as proteins, in ring structures such as sugar, as well as numerous other complex structures. There are several general differences between the chemistries of organic compounds and inorganic compounds, which will help give an overall view of organic chemistry. Carbon atoms have the capability to bond to another carbon atom and form longer chains.

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Three types of bonds are formed between carbon atoms: single bond, double bond, and triple bond. Single bond is a covalent bond formed by two carbon atoms sharing two electrons. Compounds with only single bonds between carbon atoms are known as alkanes.



C−C−C I C

Double bond consists of two covalent bonds formed by two carbon atoms sharing four electrons. Compounds with at least one carbon–carbon double bonds are called as alkenes.

Triple bonds comprise of three covalent bonds made by two carbon atoms sharing six electrons. The compounds with at least one triple bond between carbon atoms are known as alkynes.

−C ≡ C −

The simplest organic compounds are the hydrocarbons, which contain not only carbon but also hydrogen. Exposure to hydrocarbons may impact human health in

Fig. 1.18 Benzene structure

27

1.6  Organic Chemistry

H C

H

C

C

C

C H

C

H

H

H

HC

CH

HC

CH C

H Fig. 1.19  Different ways of representing the benzene structure

terms of pulmonary (related to lungs) effects, central nervous system (CNS) effects, cardiovascular (connected with heart and blood vessels) effects, gastrointestinal (related to stomach and intestine) effects, renal (relating to kidney) effects, or dermatologic effects. Hydrocarbons come in four structural classes. 1. Aromatic: these contain a benzene ring (most toxic; Figs. 1.18 and 1.19). 2. Aliphatic: these possess straight or branched chains; alkanes, alkenes, and alkynes are collectively termed as aliphatic hydrocarbons. 3. Heterocyclic: these compounds possess a ring structure in which one member is an element other than carbon. 4. Halogenated: these hydrocarbons are fluorinated, chlorinated, or brominated, and used for refrigeration (freon) or as herbicides and insecticides. Benzene is totally insoluble in water. It is a volatile liquid at room temperature, and it is fairly unreactive. Hence, it is important for the environmental engineers to eliminate it from water, air, and soil to safeguard health of living organisms including humans. The properties of the aromatics depend on substituents added to the ring. Polycyclic aromatic hydrocarbons (PAHs) generated during the incomplete combustion of organic materials are toxic substances that have direct effect on human health by interfering with the function of enzyme systems and cellular membranes (Abdel-Shafy and Mansour 2016). Benzene and PAHs are toxic air pollutants associated with emissions from motor vehicles (Whaley et al. 2020). The aliphatic hydrocarbons are derived almost exclusively from petroleum or petroleum processing. Ethylene, propylene, butadiene, isoprene, and acetylene have weak anesthetic properties at high concentrations (Vale and Meredith 1981). The associations of deoxyribonucleic acid (DNA) methylation (adding methyl group on DNA) to environmental exposure and human diseases have been widely demonstrated (Cho et al. 2018) and may contribute to adverse neurodevelopmental outcomes (Kimberly and Pamela 2016). Aliphatic hydrocarbons are of two types: saturated aliphatic hydrocarbons and unsaturated aliphatic hydrocarbons.

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Table 1.4  Main classes of organic compounds Common suffix/ Class prefix Hydrocarbons Alkanes -ane Alkenes -ene Alkynes (−yne) Arenes -ene Halogen-containing compounds Alkyl halides -halide (halo-)

General formula

Example

RH RR′C=CR″R′″ RC ≡ CR′ ArH

Ethane, methane Ethylene Acetylene (ethyne) Benzene

RX

Ethyl chloride, methyl chloride, ethylene bromide Chlorobenzene

Aryl halides HaloOxygen-containing compounds Alcohols -ol Phenols -ol Ethers Ether Aldehydes -aldehyde (−al)

ArX

Ketones -one -ic acid (−oic Carboxylic acids acid) Carboxylic acid derivatives Esters -ate (oate) Amides -amide Nitrogen-containing compounds Amines -amine

RR′C=O RCO2H

Nitriles Nitro compounds

-nitrile -nitro

ROH ArOH ROR′ RCHO

Methyl alcohol (methanol) Phenol, resorcinol Diethyl ether Acetaldehyde (ethanal), benzaldehyde Acetone (2-propanone) Acetic acid (ethanoic acid), benzoic acid

RCO2R′ RCONHR′

Methyl acetate (methyl ethanoate) N-methyl acetamide

RNH2, RNHR′, RNR′R″ RC ≡ N ArNO2

Ethylamine, aniline, benzylamine Acetonitrile Nitrobenzene

Note: Ar represents aryl group, R indicates alkyl group, X indicates halogen

Saturated aliphatic hydrocarbons are hydrocarbons in which all of the carbon– carbon bonds are single bonds. Unsaturated aliphatic hydrocarbons are hydrocarbons that have at least one double or triple bond (they are either alkenes or alkynes). Organic compounds are conveniently classified according to the functional groups (group of atom or atoms that is substituted for hydrogen or a hydrocarbon). Table 1.4 shows the main classes of organic compounds. The usual name for a group of atoms resulting from an alkane is an alkyl group. The name of an alkyl group results from the name of the alkane by adding the suffix -yl. Thus, the –CH3 fragment is a methyl group, the –CH2CH3 fragment is an ethyl group, and so forth. Groups of atoms derived from aromatic hydrocarbons are aryl groups. The – C6H5 fragment is called a phenyl group. Alkyl and aryl groups are often abbreviated as R.

1.6  Organic Chemistry

29

The term carbohydrate is used for compounds with carbon, hydrogen, and oxygen. Fats, oils, and waxes are esters. The oil exists as liquid at room temperature whereas fats and waxes remain as solid at room temperature. Hydrolysis of fats and oils is induced usually by treatment with NaOH or bacterial enzymes. Pesticides used to control pests can be inorganic, natural organic, or synthetic organic. The main types of synthetic pesticides are as follows: 1. Chlorinated pesticides. 2. Organic phosphorous pesticides. 3. Carbamate pesticides. R and R′, R″, R′″ represent any two alkyl and aryl groups, which may be alike or different. Synthetic detergents are formulations containing surfactants such as alkyl benzene sulfonate (ABS), fatty alcohol, fatty acid soaps, bleaching agents, ester and similar compounds, phosphates as well as anti-redeposition agents, optical brighteners, fabric softeners, as well as certain other chemicals to enhance the detergent action. Detergents are important to environmental professional as they form foam (Fig.  1.20), cause eutrophication (process of transformation from nutrient-scarce conditions to nutrient-rich conditions, resulting in algal blooms in water bodies), and hinder oxygen transfer to surface water bodies. The traditional heavy-duty laundry powder contains about 15% active surfactant such as linear alkylbenzene sulfonate (LAS) and 20–25% builder such as sodium tripolyphosphate (STPP). This phosphate builder is added to soften the water. One kilogram of phosphorus can generate up to 500 kg of algae causing vast dead zones in seas completely devoid of aquatic life (WWF 2011). Hence, the European Union has adopted stringent standards for phosphate content in detergents, which is not the case in other parts of the world. Prior to the widespread adoption of LAS as a surfactant, branched alkyl benzene sulfonate (ABS) was commonly used in detergents, which is a non-biodegradable or a hard detergent and has been gradually replaced by LAS.

1.7  Equilibrium Chemistry Consider the following reaction wherein carbon dioxide reacts with water to form carbonic acid:

CO2 + H 2 O  H 2 CO3

In this reaction, carbonic acid disintegrates to form carbon dioxide and water. This phenomenon calls for one more set of definition—forward and backward (or reverse) reactions.

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Fig. 1.20  Frothing in surface water streams due to detergents

Forward reaction in the above case is the combination of carbon dioxide and water. Reverse reaction is disassociation of carbonic acid to form carbon dioxide and water. The rates of forward and backward reactions are different depending on various factors such as temperature, pressure, quantity of reactants, and products. When the rates of forward reaction are equal to the rates of reverse reaction, the condition is said to be in equilibrium. The process of equilibrium occurs in many chemical reactions in the human body. The enzymes in human body catalyze forward as well as reverse reactions so that our body do not overproduce certain chemicals. The carbon dioxide formed during cellular respiration combines with water to create carbonic acid, which then dissociates into bicarbonate and a hydrogen ion to resist changes in pH within a narrow range (Hopkins and Sharma 2019). According to Le Chatelier’s principle, a reaction, at equilibrium, will adjust itself in such a way to relieve any force, or stress, that disturbs the equilibrium. Three types of stresses can change an equilibrium system: (1) Adding/removing reactants/products. (2) Changing the temperature of the system. (3) Changing the total pressure/volume. Consider a reaction wherein A and B react to produce C and D.

wA + xB +…..  yC + zD +…..

Where w, x, y, and z are number of molecules of respective reactants and products in the reaction.

1.7  Equilibrium Chemistry

31

A chemical reaction in true equilibrium can be expressed by the following equation:

[C ] [ D ] …… w x [ A] [ B] …… y

K=

z

Where K = Equilibrium constant. Any system at equilibrium, including those in the body, obeys Le Chatelier’s principle. Disruption of equilibrium of chemical reaction may result in human diseases. Most toxic effects are reversible but complete recovery may take a long time. But some poisons cause irreversible damage affecting one or many organ systems resulting in death. Five methods are commonly employed to shift chemical equilibrium to bring about essentially a complete reaction: 1. Formation of insoluble substances (e.g., precipitation of metals with calcium hydroxide). 2. Formulation of a weakly ionized compound (e.g., neutralization of acid and base). 3. Formation of complex ions (e.g., during reaction between silver chloride and ammonium hydroxide). 4. Formation of gaseous product (e.g. formation of hydrogen sulfide during reaction of ferrous sulfide and hydrochloric acid). 5. Oxidation and reduction (e.g., destruction of cyanide by chlorination). Consider the treatment of chromium-bearing wastewater by electroplating to reduce release of toxic substances to the environment. In the first stage, hexavalent chromium (Cr6+) is reduced to trivalent chromium (Cr3+) using reducing agents such as sodium bisulfite (NaHSO3), sulfur dioxide (SO2), or sodium meta-bisulfite (Na2S2O5). This reaction will progress fast when pH is between 2 and 3. The pH can be adjusted by adding an acid such as sulfuric acid.

3SO2 + 2H 2 CrO 4 + 3H 2 O  Cr2 ( SO 4 )3 + 5H 2 O



After the first-stage reaction is complete, calcium hydroxide is added to increase and maintain pH at 8 or higher for formation of chromium hydroxide to occur, which is separated by precipitation.

Cr2 ( SO 4 )3 + 3Ca ( OH )2  2Cr ( OH )3 + 3CaSO 4



A body’s homeostasis (equilibrium within a cell or the body) can be upset by physical, chemical, and/or biological agents. when homeostasis cannot be main-

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tained or restored, disease occurs. So, the changes in environment in which we live is important as any change in environment can change homeostasis affecting our health

1.8  Colloid Chemistry Colloid chemistry is a specialization of chemistry that deals with material dispersions (e.g., particulates) in solids, liquids, and gases. Table 1.5 gives some examples of colloidal suspensions. Dispersion of microscopically insoluble particles in another substance is called colloid and term colloidal suspension is used to refer to the overall mixture. To qualify as a colloid, the particles should not settle or should take a very long time to settle. The size of colloidal particles varies between about 1 and 1000 nanometers. Some colloids are known to be translucent due to Tyndall effect, which is the scattering of light by particles in suspension. The following forces are responsible for suspension of colloid particles: • Excluded volume repulsion (not able to overlap among hard particles). • Electrostatic interactions (repulsion of colloidal particles due to electrical charges possessed by them). • Van der Waals forces (interaction between two dipoles that are permanent or induced). • Entropic forces (force resulting from the tendency of a thermodynamic system to maximize its entropy). • Steric repulsion (repulsion due to overlapping electron clouds around atoms/ molecules). Unstable colloidal dispersions can form flocs and the phenomenon is widely used by environmental professionals for removal of turbidity by following means: • Removal of the electrostatic barrier accomplished by the addition of salt to a suspension. • Changing the pH of a suspension to neutralize the surface charge of the particles in suspension. • Addition of polymer flocculant to bridge individual colloidal particles or by causing aggregation due to entropic effects. Colloids are present in everybody’s cells, in the blood, and in all body fluids. Any disturbance to colloidal nature would lead to disease. Particulate air pollution is likely to contribute to their cardiovascular mortality and morbidity due to thrombotic (formation of a blood clot obstructing the flow of blood inside a blood vessel) effects (Brook et al. 2010; Robertson and Miller 2018).

1.9 Biochemistry

33

Table 1.5  Examples of colloidal suspension

Dispersion medium

Dispersed phase Gas Gas None (all gases are miscible with other gases) Liquid Foam: e.g., shaving cream Solid Solid foam: e.g., aerogel/Styrofoam

Liquid Liquid aerosol: e.g., fog, spray Emulsion: e.g., milk Gel: e.g., agar, gelatin

Solid Solid aerosol: e.g., smoke, atmospheric particulate matter Sol: e.g., paint Solid sol: e.g., cranberry glass

1.9  Biochemistry Biochemistry is a specialization of chemistry concerned with chemical processes in living organisms. The biochemical reactions that usually occur at 0–60°C, outside or inside the cell, play a significant role in health of humans and environment. Cells of living organisms oxidize inorganic as well as organic materials for energy, and bacteria are not an exception. Bacteria that oxidize organic matter for energy are called heterotrophic bacteria and those that oxidize inorganic matter are called autotrophic bacteria. The elements required by living organisms in large quantities are called bulk elements and include carbon, hydrogen, oxygen, nitrogen, sulfur, and phosphorus. The elements required by living organisms in small quantities are called trace elements and are important parts of enzymes. Some elements such as arsenic that are toxic in large quantities are vital in very small amounts, and they are called ultratrace elements. Chemicals, in human body, include organic and inorganic compounds. Inorganic substances normally disintegrate in water, forming ions. Most of the organic matters dissolve in ether or alcohol and certain organic compounds dissolve in water but do not release ions. Common inorganic compounds in living organisms include water, oxygen, carbon dioxide, as well as inorganic salts, and its availability in sufficient quality and quantity in environment is essential for health of an organism and so humans. Important groups of biochemicals in cells include lipids, carbohydrates, and proteins, besides nucleic acids. Carbohydrates Carbohydrates are biochemical molecules made up of carbon, oxygen, and hydrogen. They are water-soluble biochemicals that provide most of the energy required by cells. They also supply building blocks to build certain cell structures. Carbohydrates are often stored as reserve energy supplies. They usually have hydrogen–oxygen atom ratio of 2:1. Examples of carbohydrates include starch, sugar, and cellulose.

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Lipids Lipids are a group of biochemicals that are not soluble in water but soluble in organic solvents such as chloroform and ether. The most common lipids in human body are the fats, which primarily supply energy for cellular activities. Fat molecules are composed of carbon, hydrogen, and oxygen but has a much smaller proportion of oxygen compared to carbohydrates. Proteins Proteins consist of atoms of carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur that form the building blocks of protein called as amino acids. Proteins are structural materials, chemical messengers, and energy sources for cells. Protein misfolding can result in serious diseases. Nucleic Acids Nucleic acids carry the instructions that regulate a cell’s activities by encoding the amino acid arrangements of proteins in its building blocks. Nucleic acids comprise oxygen, hydrogen, carbon, phosphorus, and nitrogen atoms, which form the building blocks termed as nucleotides. Nucleic acids are of two types: deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). RNA, a single-stranded molecule, contains the sugar ribose while DNA, a double-stranded molecule, contains the sugar deoxyribose. DNA is responsible for storing and transferring genetic information, while RNA directly codes for amino acids and acts as a messenger between DNA and ribosomes to make proteins. Viruses contain either DNA or RNA (but not both), and a protein coat. Viral replication occurs in seven stages in host cell during the infection process, namely: 1. Adsorption. 2. Entry. 3. Uncoating. 4. Transcription/mRNA production. 5. Synthesis of virus components. 6. Virion assembly. 7. Release. As intracellular pathogens, viruses utilize various cellular structures and molecules for their propagation. Enveloped viruses attain lipid as their outer coat during interactions with cellular membranes at the time of morphogenesis within, and leaving, infected cells. Non-enveloped viruses usually exit cells by cell lysis. Even though lipid membranes are not part of the released non-enveloped virions, they interact with lipid membranes during entry into target cells (Ono 2010). Understanding chemistry would help in fighting against viral infections. For example, alcohol-based sanitizers will disrupt the lipid layer, thus stopping the virus to stick to the host cells. Soaps are effective to kill enveloped virus. Soap molecules will have hydrophilic (attracted to water) and oleophilic (attracted to oil) tails. Oleophilic tail portion of the soap molecule gets inserted into the envelope and breaks the lipid envelope of the virus.

1.9 Biochemistry

35

1.9.1  Biogeochemical Pathways A biogeochemical cycle is a pathway in which chemical transport occurs through abiotic and biotic components of the earth. The most well-known biogeochemical cycles are as follows: • • • • • •

Carbon cycle. Nitrogen cycle. Oxygen cycle. Phosphorus cycle. Sulfur cycle. Water cycle. The newly studied biogeochemical cycles include the following:

• Atrazine cycle. • Mercury cycle. Concentrations of the atmospheric carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) in 2011 surpassed the concentrations recorded in ice cores for the period of the past 800 kyr (Stocker et al. 2013). 1.9.1.1  Water Cycle Water cycle (Fig. 1.21) is one of the important biogeochemical cycles. The sun heats the water in the oceans and on surface of the earth. Some of it evaporates and some parts of water will enter the atmosphere by transpiration (loss of water from aerial parts of the plants). Some parts of water trapped in snow and ice will sublimate directly into vapor. Evaporation and transpiration together are termed as evapotranspiration. The water vapor rises in the atmosphere and condenses to form clouds and falls as precipitation. Some precipitation falls as rain, hail, and snow. Snow in warmer climates melts and joins surface water bodies. Some water bodies are formed due to melting of hail and collection of surface water. Surface water trickles into the ground. Some groundwater emerges whereas some groundwater discharge into surface water. Some water will be trapped in living things, which will be released to the environment during death, decay, drying, excretion, and transpiration. Some of the water molecules may react with other chemicals and become a new chemical. 1.9.1.2  Carbon Cycle The carbon cycle (Fig. 1.22) is one more important biogeochemical cycle. Following are the major reservoirs of carbon: • Atmosphere.

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1  Fundamentals of Chemistry for Environmental and Medical Professionals

Precipitatio n Evapotranspiration

Absorption by plants

Urban Use Evaporation

Runoff

Infiltration to ground water

Fig. 1.21  Water cycle

• • • • •

Earth’s mantle and crust. Living and non-living marine biota. Oceans. Terrestrial biosphere. The sediments.

The carbon exchanges between carbon reservoirs occur by chemical, physical, geological, and biological processes. Light



6CO2 + 6H 2 O → C6 H12 O6 + 6O2

Carbon in the earth’s atmosphere exists mostly as methane and carbon dioxide. Apart from these compounds, carbon also exists as soot, smoke, dust, and variety of other chemicals. Carbon dioxide is converted into glucose and oxygen by photosynthesis. Human activity by combustion of fuel, manufacturing, waste disposal, mining, etc. has hugely added carbon compounds to the atmosphere. Photosynthesis traps carbon dioxide and turns it into glucose, which is further converted into biomass. Animals that feed on plants will pass on the carbon along the food chain. Decay of waste excreted by living organisms and dead living organ-

1.9 Biochemistry

37

Atmospheric CO2, CO, CH4 etc.

Photosynthesis by terrestrial Respiration, Decay,

Respiration, Decay,

Photosynthesis by aquatic flora Dissolved carbon Marine Sediments, Sedimentary rocks and fossil

Fig. 1.22  Carbon cycle

isms release carbon to the environment, apart from release of carbon through weathering of biotic components of the environment. Increase in human activity has enhanced CO2 levels in the atmosphere resulting in climate change that has immense impact on human health. Carbon emissions from fossil fuel combustion and cement production from 1750 to 2011 and 2002 to 2011 were 375 and 8.3 giga tons of carbon, respectively. On the other hand, carbon emissions due to land use change (mainly deforestation) from 1750 to 2011 and 2002 to 2011 were about 180 and 0.9 giga tons of carbon, respectively. Of the 555 giga tons of carbon released to the atmosphere from fossil fuel and land use emissions from 1750 to 2011, 240 giga tons of carbon accumulated in the atmosphere. The amount of CO2 in the atmosphere grew by 4.0 giga tons of carbon per year in the first decade of the twenty-first century. As a result, CO2 concentration raised from 278 ppm in 1750 to 390.5 ppm in 2011 (Stocker et al. 2013) resulting in climate change. The CH4 concentration has also increased by a factor of 2.5 since pre-industrial times, from 722 ppb in 1750 to 1803 ppb in 2011. Some parts of carbon, carbon dioxide, and other carbon compounds dissolve in water of water bodies as well as precipitate as rain/snow/hail. When dissolved in water, carbon is converted into carbonic acid, and can then be absorbed by rocks/ soil/minerals and be washed into the ocean as well as other water bodies.

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Oceanic uptake of anthropogenic CO2 resulted in acidification of the ocean, with the pH of ocean surface water decreasing by 0.1 since the beginning of the industrial era corresponding to a 26% increase in hydrogen ion concentration. Beneficial impact of climate change includes milder winters that would decrease the seasonal winter-time peak in deaths that occur in temperate countries. Increase in temperatures may reduce the disease-transmitting mosquito populations. Climate change can result in thermal extremes and related health impacts, in winter as well as summer. Change in climate would also result in rising sea levels, disturbance of food-producing ecosystems, and hydro-meteorological disasters that include avalanches, coastal storm surges, drought, hailstorms, tornados, blizzards, tropical cyclones, thunderstorms, heavy snowfall, floods, heat waves, as well as cold spells. 1.9.1.3  Nitrogen Cycle Nitrogen cycle (Fig. 1.23) is the process in which nitrogen is converted into numerous chemical forms through chemical, physical, as well as biological processes. Nitrogen is present in the environment in various organisms in the form of organic nitrogen, ammonia, ammonium, nitrous oxide, nitrate, nitric oxide, nitrous oxide, nitrite, inorganic nitrogen gas, as well as other compounds. Nitrogen in the organic form will be present as living organisms. The N2O concentrations in the atmosphere have increased by a factor of 1.2 since pre-industrial times. Changes in the nitrogen cycle, besides interactions with CO2 sources and sinks, affect emissions of N2O from the oceans and from land (Stocker et al. 2013). The nitrogen cycle has five steps: (1) nitrogen fixation, (2) nitrification, (3) assimilation, (4) ammonification, and (5) denitrification. Conversion of atmospheric nitrogen into ammonia is called nitrogen fixation. This process is carried out by microorganisms present in the roots of leguminous plants. Nitrogen in the atmosphere is converted into N2O5 and its union with water produces HNO3, which is carried to the earth with rain and becomes nitrate by a series of reactions. Anthropogenic activities such as transportation, power generation, and manufacturing will generate oxides of nitrogen, which will contribute to acid rain and may become nitrate by a series of reactions. Photolysis also contributes to atmospheric nitrogen, wherein high-energy ultraviolet radiation disintegrates nitrous oxide in the atmosphere. Biological oxidation of ammonia into ammonium and then into nitrite followed by oxidation into nitrates is known as nitrification. Nitrate is assimilated into the plant tissue by absorption followed by a series of biochemical reactions. Animals eat plants and pass on nitrogen along the food chain. The remains of plants/animals as well as their waste products are decomposed by microorganisms into ammonia. Nitrates are reduced into inert nitrogen gas by denitrification, which completes the nitrogen cycle.

1.9 Biochemistry

2N2+5O2→2N2O5

39

Oxides of nitrogen

Combustion and antropogenic activity

Photolysis

Denitrification

N2 Assimilation Nitrogen

Animal tissue

Ammonification

Plant tissue

-

NO3

NH4 -

NO2

NH3

Nitrification

Fig. 1.23  Nitrogen cycle

Increasing use of fertilizer and fossil fuel has resulted in rise in losses of reactive nitrogen (Nr) to the environment. As a result, thresholds for environmental and human health have been exceeded due to Nr pollution, which can affect freshwater eutrophication, nitrates in drinking water, oxides of nitrogen in air, stratospheric ozone depletion, biodiversity loss, climate change, and coastal ecosystems (dead zones). Negative environmental effects can be exaggerated by the “nitrogen cascade.” Release of NOx into the lower atmosphere can result in increased tropospheric ozone formation, aerosols, smog, particulate nitrate, ammonium nitrate, and organic aerosol particles. Nitrate pollution of water poses a risk to human health (Erisman et al. 2013). 1.9.1.4  Oxygen Cycle The oxygen cycle (Fig. 1.24) is one of the important biogeochemical cycles. Largest reservoir of earth’s oxygen exists as silicate, besides oxide minerals. Only a small portion of oxygen exists as free oxygen in the atmosphere (0.36%). Photosynthesis is the main major source of atmospheric free oxygen. Photolysis also contributes to atmospheric oxygen, wherein high-energy ultraviolet radiation disintegrates nitrous oxide and water in the atmosphere.

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1  Fundamentals of Chemistry for Environmental and Medical Professionals

Anthropogenic Activity

Photosynthes

Oxygen

Carbon dioxide Photosynthes

Respiration and

Fig. 1.24  Oxygen cycle Energe



2H 2 O → 4H + O 2



2N 2 O → 4N + O2



Energe



Free oxygen is lost from the atmosphere by combustion, decay, respiration, and other atmospheric processes including reactions. The lithosphere consumes free oxygen by chemical weathering as well as surface reactions, for example, formation of iron oxides (rust).

4 FeO + O2 → 2 Fe 2 O3

Some marine organisms create calcium carbonate shell material by biochemical reactions. Animals as well as plants extract nutrient minerals from minerals/rocks and release oxygen. Oxygen concentrations have declined in the open ocean thermocline (transition layer between warmer mixed water and cooler water in surface water body) in numerous ocean regions since the 1960s, leading to a decline in the oxygen supply to the thermocline from near surface waters (Stocker et al. 2013). 1.9.1.5  The Phosphorus Cycle Phosphorus usually occurs in nature as part of a phosphate ion (PO4)3−. In the phosphorous cycle (Fig. 1.25), the phosphorus enters the soil as well as water due to the weathering of rocks and minerals. Rich deposits are normally formed in the ocean

41

1.9 Biochemistry

Animal intake

Leachet Death and Decay Plant intake

Weathering of rock

Deep Sedimentation

Fig. 1.25  Phosphorous cycle

from where it is moved to land by geologic process. Plants absorb phosphate from the soil. Phosphorus does not enter the atmosphere and remains mostly on land in rocks, soil, and minerals. Nearly 80% of the mined phosphorus is used to manufacture fertilizers. Phosphates from fertilizers, sewage, as well as detergents can cause massive algae blooms resulting in eutrophication. Animals that feed on these plants will assimilate phosphorous into their bodies and pass the phosphorous along the food chain. The phosphates absorbed by the animals are returned to the environment through excretion as well as decomposition of dead organisms and other waste products by the action of microorganisms. Eutrophication can lead to dead zones or hypoxic zones, which are very low oxygen areas in the ocean where marine life cannot survive. Overall, 405 dead zones were identified by a 2008 study worldwide (Diaz and Rosenberg 2008). Some cyanobacteria can produce toxins that are dangerous to human beings that can induce damage in humans and animals by acting at the molecular level and affecting cells, tissues, and organs in the digestive, respiratory, nervous, and cutaneous (relating to skin) systems (WHO and European commission 2002).

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1  Fundamentals of Chemistry for Environmental and Medical Professionals

Dead Plant

Healthy Plant

Toxins

Leaching

Uptake by Absorption

Fig. 1.26  Toxic cycle

1.9.1.6  Toxic Cycle Apart from nutrients, toxins also follow biogeochemical path even though it harms living organisms (Fig. 1.26). Toxins, both natural and manmade, often enter water stream and air that would affect health of the flora and fauna. The heavy metals poisoning may occur due to industrial exposure, pollution, foods, medicines, food containers, or exposure to lead-based paints. Apart from heavy metals, human health may get affected due to exposure to array of chemicals that include agrochemicals, household pesticides, pollution, and hazardous waste.

1.10  Nuclear Chemistry Atoms comprise of nucleus made up of protons and neutrons surrounded by electrons. Table 1.6 gives properties of protons, neutrons, and electrons. The protons as well as neutrons are called nucleons as they make up the nucleus of an atom. Nucleons are attracted to each other by the strong nuclear force. Stable nuclei normally have neutron-to-proton ratio of at least 1 and “even” numbers of both protons and neutrons.

1.10  Nuclear Chemistry

43

Alpha Decay

Alpha Particle

Parent Beta Decay

Beta Particle

Offspring

Positron Positron

Electron Capture Parent Electron

Offspring

x -ray

Gamma emission Parent (Excited Nuclear State)

Offspring

Gamma ray

Spontaneous Neutron s Parent (Unstable) Offspring

Fig. 1.27  Common types of nuclear decay

The two types of nuclear reactions are nuclear decay (Fig. 1.27) reactions and nuclear transmutation (Fig.  1.28) reactions. In a nuclear decay (or radioactive decay), an unstable nucleus emits radiation and is changed into the nucleus of one or more other elements. In a nuclear transmutation, a nucleus reacts with another nucleus or subatomic particle to form a product nucleus that is bigger than the starting material.

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1  Fundamentals of Chemistry for Environmental and Medical Professionals

Slow-moving

Fast-moving

New element

Fig. 1.28  Nuclear transmutation reaction Table 1.6  Properties of protons, neutrons, and electrons Particle Proton Neutron Electron

Mass (g) 1.673 × 10−24 1.675 × 10−24 9.109 × 10−28

Atomic mass (amu) 1.007276 1.008665 0.0005486

Electrical charge (coulombs) +1.602 × 10−19 0 −1.602 × 10−19

Relative charge +1 0 –1

Any nucleus that decays spontaneously is said to be radioactive. Radioactive decay happens due to emitting of subatomic particles as well as electromagnetic radiation. The process of emitting these particles is collectively termed as radioactivity. Isotopes that emit radiation are known as radioisotopes. The decline in the number of radioactive nuclei per unit time is known as the rate of radioactive decay. Radioactive decay reactions are known to be first-order reactions. The time required for decay of half of the initial number of nuclei (plural of nucleus) present is called half-life, which can vary from the fractions of a second to billions of years. Atoms of one element can be changed into atoms of another. Conversion of one chemical element or isotope into other is called nuclear transmutation. An example of the natural decay is conversion of potassium-40 to argon-40. Nuclear reactions are accompanied by huge changes in energy and mass. Changes in energy are normally reported in kiloelectronvolts or megaelectronvolts. The variation between the sum of the masses of the components of an atom and the measured atomic mass is termed as mass defect. The radioactive substance if not properly handled will affect health (Box 1.1) and environment (Box 1.2). Box 1.1 Radiation and Importance to Health Alpha, beta, and gamma radiation from radioactive substances are termed as ionizing radiation due to their ability to add/remove electrons to/from atoms. Removal of electron by ionizing radiation can disturb physiology at the chemical level resulting in clouding the lens of the eye, cancer, and interfering with normal growth as well as development.

References

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In nuclear fission (Fig. 1.29), nuclei are divided into lighter nuclei, neutrons, and energy. The minimum mass required to support a self-sustaining nuclear chain reaction (a series of nuclear fission reactions) is called the critical mass. In nuclear fusion, two nuclei combine to generate a heavier nucleus as well as high energy (Averill and Eldredge 2012). Box 1.2 Radioactive Waste Case Study Nuclear reactions are used to generate electricity in power plants by adopting neutron-induced nuclear fission (Fig. 1.29), wherein neutrons are used to split large atoms, thereby, releasing energy. Heavy-water reactors use unenriched uranium as a fuel, whereas light-water reactors use enriched uranium as a fuel.

Fig. 1.29  Neutron-induced nuclear fission

References Abbatt JPD, Wang C (2020) The atmospheric chemistry of indoor environments. Environ Sci Process Impacts 22(1):25–48. https://doi.org/10.1039/c9em00386j Abdel-Shafy HI, Mansour MSM (2016) A review on polycyclic aromatic hydrocarbons: source, environmental impact, effect on human health and remediation. Egypt J Pet 25(1):107–123 Ali F, Hosmane SN, Zhu Y (2020) Boron chemistry for medical applications. Molecules (Basel, Switzerland) 25(4). https://doi.org/10.3390/molecules25040828 Averill BA, Eldredge P (2012) Principles of general chemistry, Vol 1. https://2012books.lardbucket. org/pdfs/principles-­of-­general-­chemistry-­v1.0.pdf. Accessed on 7 December 2019 Brook RD, Rajagopalan S, Pope CA 3rd et al (2010) Particulate matter air pollution and cardiovascular disease: an update to the scientific statement from the American Heart Association. Circulation 121(21):2331–2378. https://doi.org/10.1161/CIR.0b013e3181dbece1 Chandrappa R, Kulshrestha UC (2015) Sustainable air pollution management – theory and practice, 1st edn. Springer, Heidelberg. ISBN-13: 978–3–319-21596-9 Cho Y, Song MK, Kim TS, Ryu JC (2018) DNA methylome analysis of saturated aliphatic aldehydes in pulmonary toxicity. Sci Rep 8(1):art. no. 10497

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Cracolice MS, Peters EI (2011) Basics of introductory chemistry: an active learning approach, 2nd edn. Brooks/Cole, Belmont. ISBN-13: 978–0495558477 Diaz RJ, Rosenberg R (2008) Spreading dead zones and consequences for marine ecosystems. Science 321:629 Erisman JW, Galloway JN, Seitzinger S, Bleeker A, Dise NB, Petrescu AMR, Leach AM, de Vries W (2013) Consequences of human modification of the global nitrogen cycle. Phil Trans R Soc B 368:20130116. https://doi.org/10.1098/rstb.2013.0116 Hopkins E, Sharma S (2019) Physiology, acid base balance, StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020. https://www.ncbi.nlm.nih.gov/books/NBK507807/. Accessed on 2nd July 2020 IUPAC (1996) Glossary of terms in quantities and units in clinical chemistry (IUPAC-IFCC recommendations 1996). 68(4):957–1000 IUPAC Gold book (2015a) Chemical element. http://iupac.org. Accessed on 7th September 2015 IUPAC Gold book (2015b) Oxidation state. http://iupac.org. Accessed on 7th September 2015 IUPAC(International Union of Pure and Applied Chemistry) (1992) Atomic weight: the name, its history, definition and units. Pure Appl Chem 64(10):1535–1543 Kimberly PK, Pamela JL (2016) DNA methylation: a mechanism linking environmental chemical exposures to risk of autism spectrum disorders? Environ Epigenet 2(1):dvv012. https://doi. org/10.1093/eep/dvv012 Ming-Ho Y (2005) Environmental toxicology: biological and health effects of pollutants, Chap. 12, 2nd edn. CRC Press LLC, Boca Raton. ISBN 1–56670–670-2 Mohr PJ, Taylor BN, Newell DB (2008) CODATA recommended values of the fundamental physical constants: 2006. Rev Mod Phys 80(2):633–730 Ono A (2010) Viruses and lipids. Viruses 2(5):1236–1238. https://doi.org/10.3390/v2051236 Robertson S, Miller MR (2018) Ambient air pollution and thrombosis. Part Fibre Toxicol 15(1):1. https://doi.org/10.1186/s12989-­017-­0237-­x Santisukkasaem U, Das DB (2019) A non-dimensional analysis of permeability loss in zero-valent Iron permeable reactive barrier (PRB). Transp Porous Med 126:139. https://doi.org/10.1007/ s11242-­018-­1096-­0 Stocker TF, Qin D, Plattner GK, Alexander LV, Allen SK, Bindoff NL, Bréon FM, Church JA, Cubasch U, Emori S, Forster P, Friedlingstein P, Gillett N, Gregory JM, Hartmann DL, Jansen E, Kirtman B, Knutti R, Krishna Kumar K, Lemke P, Marotzke J, Masson-Delmotte V, Meehl GA, Mokhov II, Piao S, Ramaswamy V, Randall D, Rhein M, Rojas M, Sabine C, Shindell D, Talley LD, Vaughan DG, Xie SP (2013) Technical summary. In: Stocker TF, Qin D, Plattner GK, Tignor M, Allen SK, Boschung J, Nauels A, Xia Y, Bex V, Midgley PM (eds) Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK/New York Vale JA, Meredith TJ (1981) Poisoning due to aliphatic, aromatic and chlorinated hydrocarbons. In: Vale JA, Meredith TJ (eds) Poisoning diagnosis and treatment. Springer, Dordrecht. ISBN 978–0–906141-82-3 Veerapaneni S, Long B, Freeman S, Bond R (2007) Reducing energy consumption for seawater desalination. J Am Water Works Assoc 99:95–106 Whaley CH, Galarneau E, Makar PA, Moran MD, Zhang J (2020) How much does traffic contribute to benzene and polycyclic aromatic hydrocarbon air pollution? Results from a high-­ resolution north American air quality model centred on Toronto, Canada. Atmos Chem Phys 20(5):2911–2925 WHO and European commission (2002) Eutrophication and health https://ec.europa.eu/environment/water/water-­nitrates/pdf/eutrophication.pdf. Accessed on 30th June 2020 Williams I (2001) Environmental chemistry, a modular approach. Wiley, Chichester. ISBN 0–471–48942-5

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WWF (World Wide Fund for Nature) (2011) Washing our dishes and clothes without polluting our rivers and seas the importance of an EU restriction of phosphate detergents for laundry and dishwashers. WWF Position paper, WWF European Policy Office, Brussels Zhou Y, Tol RSJ (2005) Evaluating the costs of desalination and water transport. Water Resour Res 41:1–10

Chapter 2

Fundamentals of Physics for Environmental and Medical Professionals Abstract  Knowledge of physics has been widely used in engineering and medical sciences. Movement of pollutants in the environment, separation of pollutants from waste streams, design and use of instruments required in medical and environmental fields, and spread of pathogens in air/water/soil need understanding of the fundamentals of physics. Knowledge of branches of physics such as electricity, radiation, mechanics, and heat transfer is also required by both medical and environmental professionals. This chapter discusses the fundamentals of physics, which are often the bases of environment and medical sciences.

2.1  Introduction Knowledge of physics has been widely used in engineering and medical sciences. While the medical physics deals with the application of physics in medical science, environmental professionals would be more interested in physical concepts relating to the movement of pollutants in the environment and separation of pollutants from waste streams in air, water, and soil. The human body goes through a complex series of interactions among the skeletal, muscular, and nervous systems. Biomechanics (mechanics of living organisms) and kinesiology (the study of movement of living organisms) are specializations that consider fundamentals of mechanics in human body. Kinesiology addresses biomechanical, physiological, psychological, and dynamic principles besides mechanisms of movement. Locomotion, including human movement, requires energy to overcome various forces such as friction, inertia, drag, and gravity that varies with environment. In a nutshell, understanding of statics and dynamics helps to safeguard human health at workplaces and environment by use of personal protective equipment (PPE), housekeeping, social distancing, warning signage, control of workplace environmental temperature/humidity, etc. Health physics is devoted to protecting the people and environment from potential radiation hazards, and making it possible to enjoy the beneficial uses of radiation. Chemical energy is the form of potential energy stored in chemical bonds; when they break, chemical energy is released. In addition to chemical energy, radiant, mechanical, and electrical energies are important in functioning of human body.

© Springer Nature Switzerland AG 2021 R. Chandrappa, D. B. Das, Environmental Health - Theory and Practice, https://doi.org/10.1007/978-3-030-64480-2_2

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Mechanical energy stored in the human body powers the movement of matter by muscles. Radiant energy is energy emitted as waves. Human body uses energy of sunlight to convert a compound in skin cells to vitamin D. The human eye evolved to see “visible light.” Electrical energy, supplied by electrolytes in body fluids and cells, help transmit information in nerve cells. Changes in the physical environment, such as radiation, temperature, and force (due to wind, falling objects during earthquake, rainfall, etc.), do have their implications on human health. We do not have complete control on physical activities, such as heartbeat, passage of electrical impulse in nerve cells, flow of body fluids in our body, which are directly linked to our environment. Further physical damage to body can occur due to natural and anthropogenic disasters such as earthquake, flood, road/industrial accidents, wars, and mutiny. With better understanding of physics, the concerned experts can advise decision makers to take precautionary measures or corrective action to safeguard the public health to the extent possible.

2.2  General Physics Physics is a specialization of science that is concerned with properties of energy as well as matter. It covers an array of sub-specialization and topics that include mechanics, magnetism, light and other radiation, heat transfer, electricity, sound, and the structure of atoms. Understanding the structure of atoms forms the foundation to chemistry; it is often discussed in chemistry as well. Since the structure of atoms has been discussed in the previous chapter, it will not be discussed again. Some of the frequently used terms in physics are listed in Table 2.1. Nature has four fundamental forces that exist in the environment: 1. Electromagnetic force 2. Gravitational force 3. Strong nuclear force 4. Weak nuclear force The electromagnetic force is the sum of all electrical and magnetic forces. The strong nuclear force holds protons and neutrons in the nuclei of atoms together. The weak nuclear force is the interactions between subatomic particles responsible for radioactive decay. Gravitational force acts between two objects. As per Newton’s universal law of gravitation, gravitational force is directly proportional to the product (multiplication) of their masses and inversely proportional to the square of the distance between geographical centers. In Fig. 2.1, bodies with mass m1 and m2 attract each other. Since forces exerted by each other are in opposite directions,

2.2 General Physics

51

Table 2.1  Frequently used terms in physics Sl. no. 1. 2. 3.

Term Vector Scalar Force

4.

Magnetic force

5.

Magnetic field

6. 7. 8. 9.

Work Power Energy Mechanics

10.

Statics

11.

Dynamics

12. 13.

Coplanar forces Non-coplanar force Concurrent force Non-concurrent force Parallel force Non-parallel force Collinear force Non-collinear force Gravitational force Center of gravity

14. 15. 16. 17. 18. 19. 20. 21.

22. 23. 24.

Moment of a force Resolution of force Resultant of force

Description Physical quantity that has magnitude and direction but not position Physical quantity that has only magnitude but no direction Force is any action that alters or maintains the motion of a body or distorts it Force between electrically charged particles due to their motion; it is the fundamental force responsible for attraction of magnets for iron and action of electric motors A vector field around electric current, a magnet, or changing electric field, in which magnetic forces are noticeable Work is said to be done when force causes displacement Rate of doing work is called power Capacity for doing work is called energy Specialization of science that deals with the motion of bodies under the action of forces, including the bodies at rest Specialization of mechanics that deals with bodies at rest as well as forces in equilibrium Specialization of mechanics that deals with the motion of bodies under the action of forces Forces acting in the same plane are called coplanar forces Forces acting in different planes are called non-coplanar forces Forces whose lines of action pass through a common point Forces whose lines of action do not pass through a common point Forces whose lines of action are parallel to each other Forces whose lines of action are not parallel to each other Forces with a common line of action Forces that do not have a common line of action The gravitational force is the force of attraction between two objects with mass An imaginary point in a body of matter where the total weight of the body may be thought to be concentrated for convenience in some calculations Tendency of a force to rotate the body to which it is applied about an axis or a point Splitting a force into its components A single force that has the same effect on the body as all the forces acting together are having

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m2

m1 F12

F21

r

Fig. 2.1  Schematic diagram explaining Newton’s universal law of gravitation

  F12 = − F21



Magnitude of force is mathematically explained as:

F= F= G 12 21

m1 m2 r2

Where G is Newton’s constant = 6.67 × 10−11 Nm2/kg2. For a body of mass near the surface of earth, magnitude of gravitational force will be

Fgravity = G

m1 me R2

Where me = mass of earth = 5.98 × 1024 kg R = radius of earth = 6.38 × 106 m Many forces may act upon a body during which resultant force can be identified in accordance with polygon law of forces (Fig. 2.2). If many forces are acting at a point that can be represented in direction and magnitude by the sides of open polygon in order, then their resultant shall be closing side of the polygon in the opposite direction. Motion occurs in both natural and anthropogenic environment. Dynamics is the specialization of mechanics that is concerned with the motion of bodies due to the action of forces. Some of the common terms used in dynamics are given Table 2.2.

2.2 General Physics

53

Fig. 2.2 Pictorial representation of polygon law of forces

B C

A

A E

B DP

C

RO

DP

EO

Table 2.2  Common terms used in dynamics Sl. no. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

Term Kinematics Kinetics Displacement Velocity Speed Acceleration Inertia Centrifugal force Centripetal force Momentum

Description Study of motion without reference to the forces that cause motion Relates the action of forces on objects to their resulting motions Change in position of an object is called displacement The rate of change of displacement with respect to frame of reference Rate of change of position without considering direction; it is scalar absolute value of velocity Rate of change of velocity is called acceleration Opposition to any change in velocity of an object The force away from axis of rotation of a body moving in circular motion The force toward axis of rotation of a body moving in circular motion Product (multiplication) of mass of moving body and its velocity

Newton’s Laws of Motion Newton’s laws of motion are the foundation for mechanics. Newton’s first law states that a body will remain at rest or in uniform motion in the same direction unless acted by force. The second law of motion defines a force to be equal to the change in momentum per change in time. Newton’s third law of motion states that every action has an equal and opposite reaction. Newton’s second law of motion is mathematically expressed as:



F=m

dv dt

Since the rate of change of velocity is acceleration,

F = ma

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Recalling “Newton’s law of gravitational force,” force in freely falling body on earth is mathematically represented by following formula: Fgravity = G



m1 me  m = m1  G 2e 2 R  R

  

Substituting values of me and R, me = mass of earth = 5.98 × 1024 kg R = radius of earth = 6.38 × 106 m Fgravity = 9.81 (m/s2) × m1 The value “9.81  m/s2” is the acceleration due to gravity usually denoted by abbreviation “g.” Newton’s second law is not valid when small particles (e.g., particles settling in wastewater treatment works) move at a low velocity and in non-turbulent (laminar) condition. In such condition, Stokes’ law shall be used, which has the following form: Fd = 6πµ Rv

Where:

Fd is the drag force (Stokes’ drag) between the particle and fluid μ is the dynamic viscosity R is the radius of the spherical object v is the flow velocity relative to the object Stokes’ law makes the following assumptions: • • • • •

Laminar flow Spherical particles Homogeneous (uniform in composition) material Smooth surfaces Particles do not interfere with each other

Movements of all particulate matter or “particulates,” which include dust, mist or fume, are governed by laws of physics. Such particles affect health when a person breathes them in. The movement of particles in lungs depends on the size, shape, and density of the particulate material. Apart from the physical properties, the impact on health also depends on the chemical and toxic properties of the material. Particles are deposited in the lungs by one or combination of the following four different ways: interception, impaction, sedimentation, and diffusion. • Interception: Deposition when a particle travels close to a surface of the airway passages and an edge of the particle touches the surface. • Impaction: Deposition of particles interfacing an obstacle due to inertia. • Sedimentation: Deposition due to gravitational forces.

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55

• Diffusion: Transport of particles in random motion in the lung airway by chance due to difference in particle concentration. The strategy of social distancing and lockdown during Coronavirus Disease-2019 (COVID-19) pandemic in 2019 and 2020 is based on established phenomena of physics with respect to movement of particle in the air into lungs to avoid the virus entering the lungs. Since strict social distancing is practically not fully achievable, as a mode of defense the people were advised to wear personal protective equipment such as mask and face shield. Potential and Kinetic Energies Energy changes occur due to change in position of the object. Energy possessed by an object due to the virtue of its position is called potential energy. Potential energy is an energy that is “hidden” in some way that can be converted to other forms. Types of potential energy include the following: • • • • •

Gravitational potential energy Chemical energy Nuclear energy Elastic potential energy Electrical potential energy, especially in a capacitor Equation for potential energy can be derived by definition of work done: Potential energy = work done = force × displacement



Free acceleration of free-falling body = g = 9.81 m/s2. Mathematically, Potential energy = mgh

Where

m = mass of the object at rest g = acceleration due to gravity h = height at which object is placed from reference level Energy possessed by an object by virtue of being in motion is called kinetic energy. An object will have kinetic energy due to its movement. If it is at rest, it will not have any kinetic energy. When a body falls, the potential energy stored at the top becomes converted into kinetic energy. The quantity of kinetic energy of an object depends on mass and velocity. Mathematically,

Kinetic energy =

1 2 mv 2

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According to the theory of special relativity by Albert Einstein, mass and energy can be interchanged. As per the theory, energy of a body is related to speed of light and mass by following equation. E = mc 2

Where

E = total energy of possessed by object with mass m c = speed of light = 3,00,000 km/s

Table 2.3  Common terms used in solid mechanics Sl. no. 1. 2. 3. 4. 5.

6.

7. 8. 9. 10. 11. 12. 13.

Terms Intermolecular force Elasticity

Description Force exerted by molecules on each other in an object

Property of a body due to which it regains its original configuration after removing deforming forces Perfectly elastic A body that returns to its original configuration completely and body immediately after removing deforming force from it Plasticity Property of a body due to which it is unable to regain its original shape or size even after removal of deforming force Stress The ratio of internal force generated when a body is deformed in the area on which this force acts; in equilibrium, internal force is equal to external force in magnitude; in SI unit, stress is measured in N/m2 Normal stress Normal stress is the stress generated when a force is applied perpendicular to surface of a body; normal stress is of two types— compressive stress and tensile stress Tangential stress Tangential stress is the stress generated when a force is applied parallel to surface of a body Strain It is the ratio of the alteration in size/shape to the original size/shape; strain is a dimensionless number Longitudinal Ratio of alteration in length to initial length (Fig. 2.3) strain Volumetric The change in volume divided by the original volume strain Shear strain Ratio of the length of deformation to perpendicular length in the plane of the application of force (Fig. 2.4) Elastic limit The maximum stress to which the body can recover its original size and shape on the elimination of the deforming force Modulus of Ratio of stress to the corresponding strain within elastic limits; it is elasticity constant within elastic limit as per Hooke’s law

2.3 Solid Mechanics Fig. 2.3  Illustration of compressive strain in solids

57

Force

Force ∆X

X

Longitudinal Strain (ε) = ∆ X / X

Fig. 2.4  Illustration of shear strain

∆X

Force

Y

Force Shear Strain (γ) = ∆X / Y

2.3  Solid Mechanics Human body and the environment are made up of solid and fluid. The behaviors of body fluids to force such as movement or deformation depend on established theory of mechanics. Explanation to the behavior of movement of polluting particles in gases and liquid requires knowledge of fluid mechanics. Treatment and disposal of waste need knowledge of solid mechanics. Application of the mechanics can be mainly divided into fluid mechanics and solid mechanics. Solid mechanics deals with stressing and deformation, besides failure of solid materials. The common terms used in solid mechanics are given in Table 2.3. All living organisms, including humans, are subjected to forces within and surrounding the body. Human movement is achieved through a highly coordinated and complex mechanical interactions between ligaments, muscles, bones, and joints within the musculoskeletal system (Lu and Chang 2012). Climate change and pollution will impact material properties and biomechanics of living organisms, including human beings. Climate changes are likely to result in altered wind speeds, acidification, ocean circulation, wave action, as well as increased frequency of hypoxic events (the depletion of oxygen in the bottom waters of coastal areas). These environmental drivers affect neural control and muscle function. Altered environmental conditions such as ocean acidification coupled with increased temperatures affect byssal threads of mussels as well as shells and

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Table 2.4  Common terms used in fluid mechanics Sl. no. Term 1. Compressible fluid 2. Density 3. Compressible flow 4. Incompressible flow 5. Fluid statics

6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17.

18. 19. 20.

21.

Fluid dynamics Biofluid dynamics Hemodynamics Incompressible fluid Viscosity Inviscid fluid Irrotational fluid flow Laminar flow Perfect fluid Rotational fluid flow Turbulent flow Buoyancy

Definition A fluid flow is compressible if its density changes; all real fluids are compressible and expand when heated Mass of fluid per unit volume Flow in which the fluid density changes during the flow Flow in which the fluid density is constant throughout the flow Subdiscipline of fluid mechanics that is concerned with fluids at rest as well as the pressure in a fluid or that exerted by a fluid on an immersed object Branch of fluid mechanics that is concerned with the flow of fluids Discipline of science concerned with motion of biological fluids Hemodynamics is the dynamics of blood flow Fluid whose density is constant everywhere Fluid property that relates the resistance to gradual deformation Fluid that is not viscous is called inviscid fluid Flow in which streamlines do not loop on themselves Flow in which fluid moves in parallel layers Fluid with zero viscosity Flow whose streamlines loop on themselves

Flow in which the fluid undergoes irregular fluctuations Force (F) applied on a body that is wholly or partly immersed in a fluid; mathematically,   F = ρgV where   ρ = the density of the fluid   g = the acceleration due to gravity   V = the volume of fluid directly above the curved surface Adhesion The force of attraction between molecules of different liquids or between the molecules of a liquid and a solid Cohesion Intermolecular attraction between molecules of the same liquid Surface tension Elastic tendency of a fluid surface (Fig. 2.5); it is measured as energy per unit area—joule per square meter (J/m2): a molecule inside the drop of a liquid is surrounded by other molecules that impart attractive forces from all the directions, but a molecule on the surface experiences a net attraction toward the drop, which results in surface tension Capillary action Ability of a liquid to flow against gravity in a narrow channel: adhesion of water to the walls of a container will cause an upward force on the liquid at the edges and result in a meniscus that turns upward; the surface tension acts to hold the surface intact; capillary action occurs when the adhesion to the walls of container is stronger than the cohesive forces between the liquid molecules

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Fig. 2.5 Schematic diagram for explaining surface tension in a fluid droplet

skeletons of marine invertebrates leading to decline of population and disintegration of habitats (Domenici and Seebacher 2020).

2.4  Fluid Mechanics A fluid is a material that continually flows under an applied shear stress. Fluid mechanics is the specialization of physics that is concerned with the mechanics of fluids as well as the forces on them. Common terms used in fluid mechanics are given Table 2.4. Adding surfactants (material capable of affecting the surface properties of a liquid) such as soaps and detergents that disrupt the intermolecular attractions between neighboring water molecules can decrease the surface tension of water. Lower surface tension would improve cleansing action by easy diffusion on the surface of skin (Chaudhary et al. 2020). Human biological fluids contain various biochemicals such as proteins and phospholipids capable of adsorption at fluid interfaces and play a very important role in the functioning of human organs. Surface tension of body fluids correlates directly to the development of pathological states (Fathi-Azarbayjani and Jouyban 2015).

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Table 2.5  Density of blood and its components Bibliographic entry Cutnell and Johnson (1998) Funk and Wagnalls (1985) Hinghofer-Szalkay and Greenleaf (1987) Ageyama et al. (2001)

Substance Human blood Human blood Human blood

Density (kg/ m3) 1060 1056–1066 1043–1057

Blood of cynomolgus monkeys, squirrel monkeys, and tamarins

1052.2– 1058.1

2.4.1  Density and Its Importance Density is the mass of substance per unit volume. It varies with temperature. Mathematically, density is defined as:

ρ = m /V

Where ρ = density m = mass V = volume

The density of any fluid depends on components in it such as contaminants in polluted water. Blood is composed of roughly 55% fluid plasma as well as 45% cells. Blood density (Table  2.5) also varies among species and genders within a species.

2.4.2  Pressure of Fluid at Rest If a point in the fluid is assumed of as an infinitesimally small cube, then from the principles of equilibrium the pressure on every side of this unit of fluid will be equal. Pressure on a body submerged in a fluid is: P = ρ gh

Where

ρ = density of the fluid g = acceleration due to gravity h = height of the fluid above the object If the container is open to the atmosphere above, then:

Ptotal = Patmosphere + Pfluid

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Weight of the column of air above humans is very heavy. The reason humans, or other organism, are crushed by the weight of this air is that this external pressure is balanced by internal pressure within humans, which arises from various fluids as well as materials humans are composed of.

2.4.3  Flow in Pipes Flow of fluid differs from that of channel in a way that it is at pressure wherein continuity equation and Bernoulli’s theorem are used for various calculations. 2.4.3.1  Continuity Equation A continuity equation in physics explains the conservation of mass or conservation. For an incompressible fluid flowing in a tube of changing cross-sectional area, the mass flow rate is the same throughout the tube. Mathematically: A1V1 = A2V2

Where

A1 = cross-section of area of tube at point 1 V1 = velocity in the tube at point 1 A2 = cross-section of area of tube at point 2 V2 = velocity in the tube at point 2 2.4.3.2  Bernoulli’s Theorem Bernoulli’s theorem is applicable for non-compressible liquids. It states that the “total energy of a liquid flowing from one point to another remains constant.” In a frictionless pipe, it can be expressed as:

P+

1 ρ v2 + ρ gz = constant 2

Where P = fluid pressure ρ = fluid density v = fluid velocity g = acceleration due to gravity z = elevation of the fluid above a fixed reference point

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Fig. 2.6  Line diagram of flow with varying cross-section

Point 1

a1 z1 1

p1

Point 2

a2 z1 2

p2

For the flow illustrated in Fig. 2.6 the conservation of energy equation take following form:

P1 +

1 2 1 ρ v1 + ρ gz1 = P2 + ρ v22 + ρ gz2 2 2

Where a1 = cross-section of area of tube at point 1 v1 = velocity in the tube at point 1 z1 = the elevation of the fluid above a fixed reference point at point 1 a2 = cross-section of area of tube at point 2 v2 = velocity in the tube at point 2 z2 = the elevation of the fluid above a fixed reference point at point 2 2.4.3.3  Flow in Channels A flowing stream of liquid with free surface exposed to the open air is called a liquid channel. Artificial channels and rivers convey water with a free surface exposed to air. Fig. 2.7  Flow in partially filled conduit

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Fig. 2.8  Flow in river around bodies

If the fluid is partially occupying the pipe, leaving other portion filled with air at atmospheric pressure, then one has to apply theory of channel flow (Figs. 2.7 and 2.8) discussed later in this chapter. Conventionally, for calculation with respect to flow in channel, Chézy formula or Manning’s equation is used. Chézy Formula v = C Ri

Where v = average velocity C = Chezy coefficient R = hydraulic radius = i = hydraulic gradient

Cross − sectional area Wetted perimeter

Manning’s Equation Q=



KAR 2 / 3 S 1/ 2 n

Where Q = flow rate A = cross-sectional area of flow Cross − sectional area R = hydraulic radius = Wetted perimeter

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Fig. 2.9  Obstruction to free flow of storm water drains could result in stagnation of water and becoming a mosquito-­ breeding place

S = slope of the channel n = surface roughness K = constant dependent unit (k = 1 in SI system, and K = 1.49 in FPS system) Surface roughness varies for different materials. For concrete, the value of “n” is around 0.014 and the value varies for different materials, exact value of which can be empirically evaluated. But many common materials’ values are available in the literature (Nassehi and Das 2007). Both formulae are empirical; however, Manning’s equation is more widely used as it is more accurate. Design of channels with incorrect theoretical knowledge or maintenance after construction of channels may often result in obstruction to free flow of channels. In the case of storm water drains, obstructions could result in stagnation of water that can become a mosquito-breeding place (Fig. 2.9).

2.4.4  Flows Around a Body Fluid flow around a body placed in a flow channel develops eddies (current of fluid running contrary to the main current).

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Table 2.6  Length, velocity, and time scales of environmental fluid processes and systems

Process

Atmospheric systems

Water systems

Body system

Time scale Micro turbulence Few seconds Shear turbulence Few minutes Water waves Seconds to minutes Convection Hours/days/ seasons Urban airshed Hours Sea breeze Hours Thunderstorms Hours Mountain waves Days Tornado Minutes to hours Watershed Hours to days Aquifers Seasons to decades Wetlands Days to seasons Small streams Seconds to minutes Major river Days to seasons Lakes Hours to days Estuaries Hours Coastal ocean Few days Upper ocean Weeks to decades Abyssal ocean Decades and beyond Human Seconds to circulatory system minutes Human Seconds to respiratory system minutes

Velocity scale 1–10 cm/s

Vertical length scale 1–10 cm

Horizontal length scale 1–10 cm

0.1–1 m/s

0.1–10 cm

0.1–10 m

1–10 m/s

1–100 cm

0.1–10 m

0.1–1 m/s

1–1000 m

10–1000 m

1–10 m/s 1–10 m/s 1–10 m/s 1–10 m/s 1–10 m/s

100–1000 m 100–1000 m 100–5000 m 10–1000 m 100–1000 m

1–10 km 1–10 km 1–10 km 1–10 km 1–10 km

1–10 m/s

1–10 m

1–10,000 km

1–10 m/s

10–1000 m

1–1000 km

1–10 m/s

1–10 m

10–1000 m

1–10 m/s

0.1–1 m

1–10 m

1–100 cm/s 1–10 m

10–1000 m

1–10 m/s

1–100 km

10–1000 m

0.1–1 m/s 1–10 m 0.1–1 m/s 1–100 m 1–100 cm/s 100–1000 m

1–10 km 1–100 km 10–1000 km

0.1–1 cm/s

Global

Basin depth

0.3–40 cm/s Few centimeters 0.4–1.4 m/s Few centimeters

Source: Cushman-Roisin et al. (2018); Tang et al. (2013); Wikipedia (2018)

Few centimeters Few centimeters

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Table 2.7  Application of fluid mechanics in environmental science Sl. no. Application 1 Pollution dispersion prediction

2

Water distribution system design

3

Wastewater collection system design

4

Water and wastewater treatment plant design

5

Air pollution control equipment design

6

Representative sample collection and monitoring

Brief description Water and air pollution prediction is important for decision-­ making during new projects and disaster managements to the know the movement of pollutants; concepts of fluid mechanics are used mathematically for predictive calculations Water distribution in urban local bodies, industries, commercial establishment, and housing is done through pipes under pressure; designing of the water distribution network relies on established fluid mechanics theory Wastewater from industries and urban local bodies is managed through systems of open channel and pipes; proper collection system needs an understanding of fluid mechanics concept Water and wastewater treatment require laminar flow at some stage and turbulence in other stages; proper treatment design needs knowledge of fluid mechanics Air pollution control equipment requires many fluid mechanics concepts depending on the type and quantity of pollutants to be controlled Pollution is not uniformly distributed in the environment; improper sampling planning and method may result in un representative sampling; the understanding of basic concepts helps in proper sample collection and monitoring

The flow-related force in immersed body comprises of the following: (a) A drag force in the flow direction (b) A lift force (c) A side force The drag, lift, and side forces exerted on an immersed body by a flowing fluid are perpendicular to each other.

2.4.5  Scales of Environmental Fluid Processes and Systems The factors and processes governing fluid flow in the environment occur in different sizes and scales. Table  2.6 gives some of the environmental fluid processes and systems at various dimensions. Table  2.7 gives application of fluid mechanics in environmental science. Dynamics of blood flow in human body, controlled by homeostatic mechanisms, is continuously monitored and adjusted to conditions in the body and its environment. Study of skin blood flow at 20 and 40 °C revealed constant skin blood flow until skin temperature is more than 31 °C, which varied rapidly to a further decrease in skin temperature, indicating a temperature threshold at which vascular constriction begins (Vuksanović et al. 2008). Low temperatures make blood vessels and arteries

2.5 Optics

67

narrow, restricting the blood flow and hence increasing heart beat and blood pressure to pump blood harder through the constricted blood vessels. Cold weather can impact blood flows and increase risk of a heart attack.

2.5  Optics Optics is the specialization of physics that deals with the properties and behavior of light. Working underground may increase exposure to artificial lighting, shift working as well as poor sleep quality associated with vitamin D deficiency, excessive noise, radon exposure, sick building syndrome, and negative psychological effects. (Nang et al. 2019)

Optics is of interest to environmental professionals as most of the time environmental degradation is noticed by physical observation. The change in color of water, air, soil, and snow is often an indication that not everything is normal with the environment. In some other instances, abnormality is observed due to fish kill, withering flora, abnormal increase in insects, etc. Environmental factors such as pollution by particles, toxic chemicals, microbes, variable humidity, cosmetics, ultraviolet radiations, temperature variations, affect the eyes resulting in several of eye disorders. Light pollution occurs in several forms, including sky glow (bright halo that occur over urban areas at night due to light scattering by particles in the air), light trespass (unwanted artificial light spills onto a neighboring property), glare (light that shines horizontally), over-illumination (use of artificial light beyond what is needed for a specific activity). The level of light pollution (excessive, misdirected, or obtrusive artificial light) is growing exponentially. Even after control of the light distribution, some upward light emission exists due to atmospheric scattering and reflections from the lit surfaces (Falchi et al. 2011). Anthropogenic aerosols are responsible for radiative forcing (or climate forcing, defined as the difference between sunlight absorbed by the earth and energy radiated back to space) due to aerosol–cloud interactions, aerosol–radiation interactions, and land use changes such as deforestation. Apart from radiative forcing, climate change feedbacks (increase/decrease in temperature of the atmosphere) play an important role in climate change due to changes in biogeochemical cycles, ice caps, glaciers, and sea ice, which may increase temperature (positive feedback) or decrease temperature (negative feedback). Albedo is a measure of how much light that hits a surface is reflected without being absorbed, measured on a scale from 0 (corresponds to body that absorbs all incident radiation) to 1 (corresponding to a body that reflects all incident radiation). The ecologic effects of artificial light include the following: • Behavior alteration by wildlife such as:

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–– Discouragement of turtle nesting in illuminated area –– Flying pattern of birds • Disruption of plants for seasonal variation The circadian clock (24-hour day/night cycle) influences physiologic processes in almost all organisms, which include the following (Chepesiuk 2009): • • • •

Brain wave patterns Hormone production Cell regulation Other biologic activities

Circadian clock disruption is linked to many medical disorders in humans, which includes the following (Chepesiuk 2009): • • • •

Depression Sleep disorder Cardiovascular disease Cancer

The subsequent section provides fundamentals of optics that affect environment and humans.

2.5.1  Basic Behavior of Light Light can be explained in three ways, which seems to be mutually incompatible: 1. Photons: In photon theory, light is considered as minute particles of energy moving in space at high speeds. This explanation is useful when considering the quantity of light received by a receptor or sensor. 2. Waves: In this theory, light is considered as ripples through space. This explanation is useful when explaining formation of spectrum of colors. 3. Rays: In this theory, light is considered as a path of motion of a single hypothetical photon. This explanation is helpful when defining the concept of visibility as well as explaining lenses.

2.5.2  Frequency The frequency (f) of wave is the number of times the wave peaks pass through a fixed location in unit time. Mathematically:

f = sλ

2.5 Optics Fig. 2.10 Propagating light ray from a low refractive index medium to one with a higher index

69 Normal θ1 Rarer medium Denser medium

θ2

Where λ = wavelength s = speed of wave

2.5.3  Wavelengths and Colors Wavelength of light corresponds to a spectral color. Wavelengths from 700 to 1000 nm are called infrared, and wavelengths from 100 to 400 nm are called ultraviolet, which are not part of visible spectrum. Visible light spectrum (range of wavelengths visible to humans) corresponds to the range of electromagnetic waves with wavelengths ranging from 400 to 700 nm.

2.5.4  Angle of Incidence, and Refraction When light travels from a rarer medium to a denser medium, it bends toward the normal and vice versa (Fig. 2.10). The angle that an incident or ray makes with a line perpendicular to the surface at the point of incidence is called angle of incidence. The angle made by a refracted ray with a line perpendicular to the refracting surface is called angle of refraction. In Fig. 2.10, θ1 is the angle of incidence and θ2 that of refraction.

2.5.5  Index of Refraction The index of refraction of a media is the ratio of speed of light in vacuum to speed of light in the medium, which can be expressed mathematically as follows:

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n=



c v

Where n = index of refraction c = speed of light in vacuum v = speed of light in medium

2.5.6  Snell’s Law Snell’s law or law of refraction relates to the refractive indices of two different materials with the angles of reflection and refraction as:



n1 sin θ 2 = n2 sin θ1



or

n1 sin θ1 = n2 sin θ 2

Where n1 = refractive index of material 1 n2 = refractive index of material 2 θ1 = angle of incident light ray in material 1 θ2 = angle of refracted light ray in material 2

Fig. 2.11  Illustration of critical angle n1>n2

n2

Rarer medium

θ2=90o n1

Denser medium θ1=θc

2.5 Optics

71

Fig. 2.12  Total internal reflection n1>n2

n2

Rarer medium

θ2=90o

n1

n1 Denser medium θ1>θc

2.5.7  Total Internal Reflection Complete reflection of light within a medium is called total internal reflection. The angle of incidence beyond which light ray from denser to rarer medium will no longer be refracted but totally reflected is called critical angle (Figs.  2.11 and 2.12).

2.5.8  Interactions with Materials When light rays fall on the surface of an object, they can be absorbed, transmitted, or reflected (Fig. 2.13). In the case of a transparent material, the transmitted light rays will slow down and bend in accordance with Snell’s law. In the case of translucent materials, the rays scatter in different directions before going out. In a perfectly smooth surface, if angle of reflection is equal to the angle of incidence it is called specular reflection. If the reflected rays scatter in different directions, it is called diffusive reflection (Fig. 2.14).

2.5.9  Prism Prism is a solid shape with the same polygonal base on both sides. In optics, a prism is of interest due to the ability of transparent prism to disperse light. Triangular prism with a triangular base and rectangular sides (Figs.  2.15 and 2.16) is colloquially called “prism” in optics. Typical materials that are used to make prism for optical application include glass, plastic, and fluorite.

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Fig. 2.13 Pictorial depiction of transmission, absorption, and reflection

Reflection Absorption Absorption

Transmission

Specular Fig. 2.14  Schematic diagram of specular and diffusive reflections

Fig. 2.15  Different views of a prism

Diffusive Gas

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73

Fig. 2.16  Line diagram of light passing through a prism

Table 2.8  Definition of common terms with respect to lens Sl. no. 1. 2. 3. 4. 5. 6.

7.

8.

Term Convex lens

Description Lenses that are thinner at edges and thicker at the middle; rays of light that pass through the lens converge Concave lens Lenses that are thicker at edges and thinner at the middle; rays of light that pass through the lens diverge Optical center of Central point of the lens through which a ray of light passes without lens suffering any deviation Focal point lens Point in space where parallel light rays meet after passing through the lens Focal length lens Distance between the focal point of lens and its optical center Straight line passing through the geometrical center of a lens and two Optical axis of centers of curvature lens/principal axis Real image A real image is formed in the plane of convergence of rays of light that originate from an object; real image will generally become visible on a screen placed in the plane of a real image Virtual image The virtual image appears to be formed when light rays that originate from the object diverge but cannot be projected onto a screen

2.5.10  Lenses Lens is a transparent substance with curved sides for dispersing or concentrating light rays. The common terms with respect to lenses are given in Table 2.8. 2.5.10.1  Simple Convex Lens A simple convex lens with parallel light rays falling on the surface is shown in Fig. 2.17. Suppose a lens has focal length f and an object is placed at distance s1 from the lens, then the image will be formed only when the equation given below is satisfied:

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Fig. 2.17  A simple convex lens

Focal Plane

Focal Point

f Focal Length

S1

S2

Object f

f

f

f

Image

Fig. 2.18  Line diagram showing the object between f and 2f



1 1 1 + = s1 s2 f

Image formed by convex lens depends on distance of the object from the lens. Figures 2.18, 2.19, 2.20, 2.21, 2.22, and 2.23 depict line diagrams of image formation by convex lens when the object is placed at different locations.

2.5.11  Chromatic Dispersion The change in speed of light as it travels from one medium to another causes the light to be refracted. The degree of bending depends on the angle of incidence as well as the refractive indices of the media. The refractive indices of many materials differ with the wavelength of the light, which causes light of various colors to be refracted differently. Chromatic dispersion is a phenomenon by which different spectral components of light travel at varied velocities. Chromatic dispersion results in separation of colors in a prism (Fig. 2.24) and chromatic aberration in lenses.

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2.5 Optics

Image

f

f

f

Fig. 2.19  Line diagram showing the object at f

Image

f

f

f

f

Fig. 2.20  Line diagram showing the object between f and o

2.5.12  Mirror Mirror is an object that reflects light from its surface, with little or no diffusion. The common terms associated with respect to mirror are given in Table 2.9. 2.5.12.1  Law of Reflection The law of reflection states that: 1. The reflected ray, the incident ray, and the normal to the surface of the mirror lie in the same plane. 2. The angle of incidence is equal to the angle of reflection (Fig. 2.25). 2.5.12.2  Application of Optics in Environmental Health Optics has many applications in environmental science and health. Some of them are as follows:

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Image f

f

f

f

Fig. 2.21  Line diagram showing the object at 2f

Image f

f

f

f

Fig. 2.22  Line diagram showing the object beyond 2f

• Pollution monitoring instrumentation and devices (e.g., optical sensors for heavy metal detection) • Health check-up instrumentation • Using solar energy Studies on spatial and temporal characteristics of night time light (NTL) before and during the COVID-19 pandemic in mainland China revealed the monthly average NTL brightness was much lower during the quarantine period than before—due to lockdown and quarantine policies (Liu et al. 2020).

2.6  Acoustics Sound is the sense felt by the human ear due to rapid variations in air pressure. Acoustics was originally restricted to sound, which is created due to pressure waves in air, which can then be detected by the human ear. Later, the scope of acoustics was extended to ultrasound and infrasound, which have higher and lower frequencies, respectively, compared to sound. Noise exposure is linked to disturbance of the homeostasis, annoyance, sleep disturbance, hypertension, physiological distress, sleep loss, increasing allostatic

2.6 Acoustics

77

Image

f

f

f

f

Fig. 2.23  Line diagram showing the object at infinity Fig. 2.24 Chromatic dispersion in a prism

load (the wear and tear on the body), concentration difficulties, and cardiovascular disease (Basner et al. 2014; Münzel et al. 2020; Eriksson et al. 2018; Basner et al. 2014; WHO 2018; Brown and Van 2017; Guski et al. 2017).

2.6.1  Wave Terminology There are a number of terms in common, of which the more important terms are defined in Table 2.10.

2.6.2  Sound Energy Density The quantity of sound energy per unit volume of a sound wave is called the sound energy density. Sound energy affects a receiver depending on the distance of the receiver from the source of sound. Acoustics near field is a distance up to two wavelengths from sound source (Fig. 2.27). Distance beyond two wavelengths is considered as far field. A diffusive

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Table 2.9  Definition of common terms with respect to mirror Sl. no. 1. 2.

Term Plane mirror Convex mirror

3.

Concave mirror

4.

Focal point of mirror Focal length mirror Optical axis of lens

5. 6.

Description Mirror with a flat (planar) reflective surface Mirror with reflective surfaces that curve outward; convex mirrors reflect light outward Mirror with reflective surfaces that curve inward; convex mirrors reflect light inward Point in space where parallel light rays meet after reflecting through the mirror Distance between the center of a mirror and its focal point Straight line that passes through its center of curvature and geometric center

Fig. 2.25  Line diagram of incident ray and reflected ray

Normal Incident Ray

Reflected Ray

Angle of Incident

Angle of Reflection

field is an acoustic field where sound waves reach the receiver from all directions directly or indirectly by reflection. In free acoustic field, there are no reflections. Receiver receives sound directly from the sound source.

2.6.3  Sound Intensity Sound power per unit area is called sound intensity.

2.6.4  Intensity Level The intensity level is defined by: Where

IL = 10 log10 ( I / I o )

2.6 Acoustics

79

Table 2.10  Important wave terminologies Sl. no. 1. 2. 3. 4. 5. 6. 7. 8. 9.

Term Wave front

Definition/description Imaginary surface representing similar points of a wave that vibrate in unison Plane wave A wave whose wave fronts are in finite parallel planes Diverging wave Wave in which the energy is spread over a larger and larger area Spherical wave Wave created by a sound source that radiates the energy equally in all directions Progressive When there is a transfer of energy in the direction of transmission of the wave sound, the wave is called as progressive Period of wave Time taken for the oscillation to repeat itself (Fig. 2.26) Amplitude of The maximum displacement of a vibrating particle (Fig. 2.26) wave Sound power Rate at which sound energy is transmitted, emitted, received, or reflected per unit time; the SI unit of sound power is watt Sound energy Form of energy generated when an object vibrates; in SI unit, it is measured in joules

IL = intensity level expressed in decibels I = intensity of sound Io = the reference intensity usually taken as 10−12 W/m2

2.6.5  Sound Pressure Level The sound pressure level is defined by: SPL = 20 log10 ( Prms / Po )

Where

SPL = sound pressure level in decibels Po = the reference sound pressure levels of 0.00002 Pa Prms = root mean square pressure of sound The instrument used to measure sound pressure level is called sound level meter.

2.6.6  Sound Power Level The sound power level is a measure of the acoustic energy emitted from a sound source. Mathematically:

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Period1kg Amplitude Time

Fig. 2.26  Line diagram of sound wave Wavelength Amplitude Distance 2 wave length

2 wave length to infinity

Near Field

Far Field

Sound Source

Fig. 2.27  Line diagram explaining acoustics near field and far field



SWL = 10 log10 ( W / Wo )

Where SWL = sound level power expressed in decibels W = the acoustic power of the source Wo = the reference acoustic power of 10−12 W

2.7  Electrical and Electronics As discussed in Chap. 1, atoms are made up of negatively charged particles electrons, positively charged particles protons, besides neutral particles neutrons.

2.7 Electrical and Electronics

81

Table 2.11  Common terms used in electrical and electronics sciences Sl. no. Term 1. Electric charge

2.

Coulomb

3.

Electrical current

4.

Ampere

5.

Electric potential

6. 7.

Volt Potential difference

8. 9.

Electrical conductance Electrical resistance

10. Electric power 11. Electric circuit 12. Electric field

13. Magnetic field

14. Electromagnetic field (EMF)

15. Electric load

Description Property of matter responsible for electrical phenomena; it is measured by coulomb; electron has a charge of “−1.602 × 10−19 coulomb” while proton has a charge of “1.602 × 10−19 coulomb” Coulomb is the SI quantity of electricity transported in 1 s by a constant current of 1 A Electric current is the rate of flow of electrons, through a conductor Electric current is measured in ampere, which is the flow of 1 coulomb of electric charge (or 6.242 × 1018 electrons) per second Potential energy of a unit charge; it is the property of location within the electric field Units of electric potential: 1 volt = 1 joule/coulomb The variance in electrical potential amid two points is called potential difference The ease of flow of electric current; it is measured in mhos Opposition to the movement of electric current; unit of measurement of electrical resistance is ohm (Ω) Electric power is the work done by an electrical current; it is measured in Watt An electric circuit is a route in which electrons from source of electric current move Electric fields are region around an electrically charged object or particle wherein an electric charge feels the force; strength of electric field depends on electric potential; unit of electric field strength is volt per meter (V/m) The area around an object where magnetic force is felt is called magnetic field; magnetic fields are formed around electrical flow and magnets; higher current will generate stronger magnetic field; magnetic field is measured in tesla (T) Property of space produced by motion of an electric charge; while a stationary charge produces only an electric field, electric current will generate magnetic field also, which together form electromagnetic field Electric load is the part of the circuit that performs work (e.g., a television, motor) Electric current flowing only in one direction

16. Direct electric current (normally termed as direct current) 17. Alternating electric current Electric current that reverses its direction numerous times in a time period (normally termed as alternating current)

(continued)

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Table 2.11 (continued) Sl. no. Term 18. Electronics 19. Diode 20. Capacitor 21. Transistor 22. Transformer 23. Step-up transformer 24. Step-down transformer

Description Specialization of science that is concerned with control of the motion of electrons Electronic device that permits electric current to move through it in single direction Electronic device that stores electrons Device used to regulate electric current or potential difference and that acts as a gate for electronic signals Electrical device used to transfer electrical energy among two or more circuits Transformer in which the output electric potential difference is greater than its input Transformer in which the output electric potential difference is less than that of the input

Fig. 2.28  Transmission and distribution of electricity

Three basic descriptions used in electrical and electronics sciences is given in Table 2.11. Ohm’s Law Ohm’s law states that electric current is inversely proportional to electrical resistance and directly proportional to the potential difference amid two points. Mathematically: I = V / R

Where

I = electric current V = potential difference between two points

2.7 Electrical and Electronics

83

R = resistance between two points Resistance of any material is affected by the type of material, length of material, temperature of material, and cross-section area of the material that is perpendicular to the transmission of the electric charge. Electric and magnetic fields are present where electricity is generated/transmitted/distributed (Fig. 2.28). These fields are omnipresent in our environment. Electric fields in a circuit are created by potential difference. Higher the potential difference, the stronger the electrical field. Extremely low-frequency magnetic fields are categorized as a “possible human carcinogen” by the International Agency for Research on Cancer (IARC 2002). Electromagnetic fields exist ubiquitously in our environment. Electric fields are generated in the atmosphere due to thunderstorms. All materials (e.g., soil) also have electric properties, e.g., electrical permittivity and conductivity (Hummel 1998; Rabiu et al. 2017). The electricity used in day-to-day life generates low-frequency electromagnetic fields. Higher-frequency radio waves are used in day-to-day life in television, radio, and mobile phone for transmitting information. Electromagnetic waves are series of invisible waves traveling at a huge speed. Frequency of electromagnetic wave is the number of occurrences of cycle per unit time. Wavelength of these waves is the distance between two adjacent waves. Effects of EMF vary with different frequencies. Some electromagnetic waves have the ability to break bonds between molecules. Such waves and are called “ionizing radiation.” Other waves are called “non-­ ionizing radiation.” Exposure to external magnetic and electric fields at very low frequencies induces electric fields as well as currents within the body and stimulates excitable tissues such as muscle and nerve. Electric current of higher magnitude will affect muscles making fingers into a fist. Hand touching live wire will grasp the wire firmly, and victim will not be able to leave the wire with current. Even after stopping the current, the victim may not reclaim voluntary control of their muscles for some time. Relatively low electric currents affect heart functioning making heart flutter instead of beating, thereby hindering flow of blood to vital body organs. Strong enough electric current can also lead to death due to cardiac arrest and/or asphyxiation. As electric current through a material results in a release of energy, normally as heat, so in living organisms it may result in burning of the tissue and organs (Health and Safety Authority 2019). Apart from electric safety, waste from electrical and electronic equipment is of great health concern for environmental and health professionals, which is dealt in detail in the subsequent chapters.

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Table 2.12  Common terms used in thermal physics Sl. no. 1.

Term Thermal energy

2. 3. 4.

Heat Temperature Melting point

5.

Flash point

6.

Ignition point

7.

Boiling point

8. 9. 10.

Thermometer Calorie Specific heat

Description Thermal energy is internal energy in a system in a state of thermodynamic equilibrium due to its temperature Heat is the flow of thermal energy Relative hotness or coldness of an object Temperature at which a solid will melt is called melting point of that solid Lowest temperature at which vapors of a material ignite by external ignition source The lowest temperature at which a volatile material will be vaporized into a gas that ignites without external ignition source is called ignition point Temperature at which liquid is transformed into its vapor without raising the temperature Thermometer is an instrument for measuring temperature The energy required to raise the temperature of 1 g of water by 1 °C Quantity of heat required per unit mass to increase the temperature by 1 °C; mathematically, Cp =  

11.

Latent heat

12.

Heat of fusion

13.

Latent heat of fusion Heat of vaporization Latent heat of vaporization Heat capacity Standard heat of combustion

14. 15. 16. 17.

q M ∆T

where   Cp = specific heat   q = the heat added in Calories   M = the weight of the material in grams   ΔT = the rise in temperature of material in degree Celsius Energy released or absorbed by a substance during a transformation in its physical state that occurs without change in temperature Amount of heat necessary to melt a substance at its normal melting temperature Quantity of heat required to convert unit mass of solid into its liquid state without change in its temperature Heat necessary to evaporate the substance at its normal boiling point The amount of heat required to convert unit mass of liquid into its vapor state without change in its temperature Ratio of heat absorbed by a substance to the change in temperature Amount of heat evolved at one atmosphere pressure and at 25 °C when one mole of a substance is burned in excess oxygen.

2.8  Thermal Physics Thermal physics is the study of heat. Heat is generated naturally and artificially. Heat transfer has much applications, but uncontrolled heat can lead to disasters and

2.8 Thermal Physics

85

Table 2.13  Relationships of different temperature scales

Absolute zero Freezing point of water Boiling point of water

Scale Kelvin (°K) 0° 273.15° 373.15°

Celsius (°C) −273.15° 0° 100°

Fahrenheit (°F) −459.67° 32° 212°

Rankine (°R) 0° 491.67° 671.64°

affect health. Application of heat is well known in the following: • • • • • •

Transportation Industry Domestic activity Mining Wars and mutiny Waste management

The above applications are also the causes of many types of pollution and release many pollutants. Table 2.12 gives the common terms used in thermal physics. The centigrade scale was developed in 1742, now known as the Celsius temperature scale named after the Anders Celsius, which uses the boiling point of pure water as 100 °C and the freezing point of pure water 0 °C (Fuller et al. 1978). Other scales were named after William John Macquorn Rankine, Daniel Gabriel Fahrenheit, and Lord Kelvin. Relationships of different temperature scales are shown in Table 2.13. Molecules in the gas phase can re-enter the liquid via a phenomenon called condensation. When the number of molecules evaporating as well as condensing per unit time is the same, the system is said to be in a state of dynamic equilibrium. Liquids with high vapor pressures are called volatile liquids and tend to evaporate readily from an open container whereas non-volatile liquids have low vapor pressures. As the temperature of a liquid increases, the vapor pressure of the liquid rises until it is same as the external pressure (atmospheric pressure in the case of an open container). At this point of time, bubbles of vapor are formed in the liquid resulting in boiling. The temperature at which a substance boils at 1 atm pressure is called the normal boiling point of the substance. Temperature has a role to play in human health and global ecological balance. As per Geneva et al. (2019), the temperature ranges published were 36.32–37.76 (rectal), 35.76–37.52 (tympanic), 35.61–37.61 (urine), 35.73–37.41 (oral), and 35.01–36.93 (axillary). People with age ≥60 had lower temperature than younger adults with age  T2. As per the second law of thermodynamics, total entropy of a system either increases or remains constant; it never decreases. Since the temperature of the environment varies, temperature within the human body is maintained by increasing (by shivering, increase in blood transport) or decreasing (by sweating) it in natural settings. When the body fails to comply with the second law of thermodynamics in natural settings, the person has to: • Change the temperature of the immediate surroundings (e.g., by air conditioner/ cooler or room heater as per the situation). • Wear warm cloths to conserve energy if the person is feeling cold. • Perform physical activity to increase catabolic activity to release energy within the body. • Consume food/drinks with warm/cold temperature (as per the situation). Failure to comply with the second law of thermodynamics by a healthy person will disturb his health.

2.9.3  Third Law of Thermodynamics The third law of thermodynamics states that the entropy of a perfectly ordered solid at absolute zero (0° K) is zero. Thermal energy is transferred from one point to another by radiation, convection, and conduction. In conduction, heat is transferred by direct transfer of heat through the matter, due to the variation in temperature, among adjacent parts of the object. In convection, heat is transferred by movement of matter in fluids. In radiation, the heat transferred is by radiation.

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2.9.4  Survival in Cold Climates Metabolic rate decreases with age and hence energy cannot be generated as fast as it is dissipated. Hypothermia, a dangerous drop in human body temperature below 35°, can be serious if not treated immediately. Respiratory epidemics, direct hemodynamic responses to cold, poor indoor air quality, and sudden exertion (expenditure of energy) likely contribute to cold-related mortality (Gronlund et al. 2018). Under normal conditions, human body readjusts in the temperature range of 37–35  °C.  When the body’s temperature decreases, the body produces the extra energy to compensate. Below 35  °C, the human body cannot produce sufficient energy as fast as temperature is being lost.

2.9.5  Survival in Hot Climates Thermal energy from human body is displaced due to radiation, convection, conduction, respiration, and evaporation of sweat by skin. Long-term augment in temperature variability may amplify the risk of mortality in various subgroups of vulnerable older populations (Zanobetti et al. 2012). Transfer of energy from the environment into the human body without dissipating mechanism leads to increase in the body’s temperature, and thus to heat stress, which could further lead to heat stroke and death. This is brought to steady state by perspiration. Energy from the body would vaporize sweat resulting in cooling effect. Heat exposure leads to the following abnormalities: • Heat edema: swelling of human body in those who are unaccustomed to working in hot surroundings • Heat rashes: development of tiny red spots on the skin with prickling sensation • Heat cramps: sharp pains in the muscles • Heat exhaustion: excessive sweating • Heat syncope: heat-induced dizziness besides fainting • Heat stroke: partial loss of consciousness

References Ageyama N et al (2001) Specific gravity of whole blood in cynomolgus monkeys, squirrel monkeys, and tamarins. Contemp Top Lab Anim Sci 40(3):33–35 Basner M, Babisch W, Davis A, Brink M, Clark C, Janssen S, Stansfeld S (2014) Auditory and non-auditory effects of noise on health. Lancet 383(9925):1325–1332. https://doi.org/10.1016/ S0140-­­6736(13)61613-­­X Bhalse D, Kame R, Malviya P, Sharma P, Mishra A (2016) A review paper of the laws of thermodynamics to apply the human bodies. Int J Sci Res Multidiscip Stud 2(8):1–4

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Brown AL, Van KI (2017) WHO environmental noise guidelines for the European region: a systematic review of transport noise interventions and their impacts on health. Int J Environ Res Public Health 14(8):873 Chaudhary N K, Bhattarai A, Guragain B, and Bhattarai A (2020) Conductivity, surface tension, and comparative antibacterial efficacy study of different brands of soaps of Nepal. J Chem 2020, 6989312, 13 pages doi:https://doi.org/10.1155/2020/6989312 Chepesiuk R (2009) Missing the dark: health effects of light pollution. Environ Health Perspect 117(1):A20–A27. https://doi.org/10.1289/ehp.117-­­a20 Cushman-Roisin B, Gualtieri C, Mihailovic DT (2018) Chapter 1: Environmental fluid mechanics: current issues and future outlook. In: Gualtieri C, Mihailovic DT (eds) Fluid mechanics of environmental interfaces, 2nd edn. Boca Raton: CRC Press/Balkema, pp 3–17 Cutnell JD, Johnson KW (1998) Physics, 4th edn. Wiley, New York, p 308 Domenici P, Seebacher F (2020) The impacts of climate change on the biomechanics of animals. Conserv Physiol 8(1):coz102. https://doi.org/10.1093/conphys/coz102 Eriksson C, Pershagen G, Nilsson M (2018) Biological mechanisms related to cardiovascular and metabolic effects by environmental noise. World Health Organization, Geneva Falchi F, Cinzano P, Elvidge CD, Keith DM, Haim A (2011) Limiting the impact of light pollution on human health, environment and stellar visibility. J Environ Manag 92(10):2714–2722. https://doi.org/10.1016/j.jenvman.2011.06.029 Fathi-Azarbayjani A, Jouyban A (2015) Surface tension in human pathophysiology and its application as a medical diagnostic tool. Bioimpacts 5(1):29–44. https://doi.org/10.15171/bi.2015.06 Fuller HQ, Fuller RM, Fuller RG (1978) Physics, including human applications. Harper & Row, New York Funk and Wagnalls (1985) Blood. Encyclopedia 1985:157 Geneva II, Cuzzo B, Fazili T, Javaid W (2019) Normal body temperature: a systematic review. Open Forum Infect Dis 6(4):ofz032. https://doi.org/10.1093/ofid/ofz032 Gill S, Handley J, Ennos A, Pauleit S (2007) Adapting cities for climate change: the role of the green infrastructure. Built Environ 33:115–133 Gronlund CJ, Sullivan KP, Kefelegn Y, Cameron L, O’Neill MS (2018) Climate change and temperature extremes: a review of heat- and cold-related morbidity and mortality concerns of municipalities. Maturitas 114:54–59. https://doi.org/10.1016/j.maturitas.2018.06.002 Guski R, Schreckenberg D, Schuemer R (2017) WHO environmental noise guidelines for the European region: a systematic review on environmental noise and annoyance. Int J Environ Res Public Health 14(12):1539 Health and Safety Authority (2019) Dangers of electricity. https://www.hsa.ie/eng/Topics/ Electricity/Dangers_of_Electricity/. Accessed on 22 Mar 2019 Hinghofer-Szalkay HG, Greenleaf JE (1987) Continuous monitoring of blood volume changes in humans. J Appl Physiol 63:1003–1007 Hummel RE (1998) Electrical properties of materials. In: Understanding materials science. Springer, New York. isbn:978-1-4757-2974-0 IARC (2002) Monographs on the evaluation of carcinogenic risks to humans, vol 80. IARC, Lyon Liu Q, Sha D, Liu W, Houser P, Zhang L, Hou R, Lan H, Flynn C, Lu M, Hu T, Yang C (2020) Spatiotemporal patterns of COVID-19 impact on human activities and environment in Mainland China using nighttime light and air quality data. Remote Sens 12(10):1576 Lu TW, Chang CF (2012) Biomechanics of human movement and its clinical applications. Kaohsiung J Med Sci 28(2 Suppl):S13–S25. https://doi.org/10.1016/j.kjms.2011.08.004 Münzel T, Kröller-Schön S, Oelze M, Gori T, Schmidt FP, Steven S, Hahad O, Röösli M, Wunderli J, Daiber A, Sørensen M (2020) Adverse cardiovascular effects of traffic noise with a focus on nighttime noise and the new WHO noise guidelines. Annu Rev Public Health 41:309–328. https://doi.org/10.1146/annurev-­­publhealth-­­081519-­­062400. PMID 31922930 Nang EE, Abuduxike G, Posadzki P, Divakar U, Visvalingam N, Nazeha N et al (2019) Review of the potential health effects of light and environmental exposures in underground workplaces. Tunn Undergr Space Technol 84:201–209

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Nassehi V, Das DB (2007) Computational methods in the management of hydro-environmental systems, 1st edn. IWA (International Water Association), London. ISBN-10: 1843390450 Popovic M, Minceva M (2020) A thermodynamic insight into viral infections: do viruses in a lytic cycle hijack cell metabolism due to their low Gibbs energy? Heliyon 6(5):e03933. https://doi. org/10.1016/j.heliyon.2020.e03933 Rabiu KO, Abidoye LK, Das DB (2017) Geo-electrical characterisation for CO2 sequestration in porous media. Environ Process 4:303–317. https://doi.org/10.1007/s40710-­­017-­­0222-­­2 Schneider A, Breitner S (2016) Temperature effects on health – current findings and future implications. EBioMedicine 6:29–30. https://doi.org/10.1016/j.ebiom.2016.04.003 Stocker TF, Qin D, Plattner GK, Alexander LV, Allen SK, Bindoff NL, Bréon FM, Church JA, Cubasch U, Emori S, Forster P, Friedlingstein P, Gillett N, Gregory JM, Hartmann DL, Jansen E, Kirtman B, Knutti R, Krishna Kumar K, Lemke P, Marotzke J, Masson-Delmotte V, Meehl GA, Mokhov II, Piao S, Ramaswamy V, Randall D, Rhein M, Rojas M, Sabine C, Shindell D, Talley LD, Vaughan DG, Xie SP (2013) Technical summary. In: Stocker TF, Qin D, Plattner GK, Tignor M, Allen SK, Boschung J, Nauels A, Xia Y, Bex V, Midgley PM (eds) Climate change 2013: the physical science basis. Contribution of Working Group I to the fifth assessment report of the intergovernmental panel on climate change. Cambridge University Press, Cambridge/New York Tang JW, Nicolle AD, Klettner CA, Pantelic J, Wang L, Suhaimi AB, Tan AY, Ong GW, Su R, Sekhar C, Cheong DD, Tham KW (2013) Airflow dynamics of human jets: sneezing and breathing – potential sources of infectious aerosols. PLoS One 8(4):e59970. https://doi.org/10.1371/ journal.pone.0059970 Vuksanović V, Sheppard LW, Stefanovska A (2008) Nonlinear relationship between level of blood flow and skin temperature for different dynamics of temperature change. Biophys J 94(10):L78–L80. https://doi.org/10.1529/biophysj.107.127860 WHO (2018) Environmental noise guidelines for the European region. World Health Organization, Geneva Wikipedia (2018) Hemodynamics. https://en.wikipedia.org/wiki/Hemodynamics#cite_note-­­14. Accessed on 13 Oct 2018 Zanobetti A, O’Neill MS, Gronlund CJ, Schwartz JD (2012) Summer temperature variability and long-term survival among elderly people with chronic disease. Proc Natl Acad Sci U S A 109(17):6608–6613. https://doi.org/10.1073/pnas.1113070109

Chapter 3

Fundamentals of Biology for Environmental and Medical Professionals Abstract  Prevention of diseases is better than cure. Achievement of prevention of diseases requires efforts from anyone starting with the head of a state to social scientists, financial experts, wildlife professionals, people from the media, and other individuals. Body fluids are known to be mixtures of biochemicals and cells. Similarly, rivers, lakes, estuaries, and oceans are also complex mixtures of unicellular and multicellular organisms that are unique to each water body, and within each one of these, the ecological setup is different. Injury or illness to humans disturbs the body’s homeostasis (the state of steady internal conditions conserved by living things). Alteration or pollution of water body could lead to epidemics, floods, and other incidents that may affect the health of individuals. Further human activities can alter the quantity of disease causative agents. In other words, anthropogenic activity can either increase or decrease the quantity of disease causative agents such as pathogens or toxic substances in the environment. Many of the causative agents can be prevented from entering the environment by adopting a proper waste management approach and other good practices. This chapter discusses the fundamentals of biology, which forms part of the basis of environmental and medical sciences.

3.1  Introduction Prevention of diseases is better than cure. It saves life, money, and time. Instead of approaching a doctor with ailment and pain, humans themselves can prevent diseases to a great extent, if not completely. Achievement of prevention of diseases requires efforts from anyone starting with the head of a state to social scientists, financial experts, wildlife professionals, people from the media, and other individuals. Blood is a mixture of biochemicals and cells. Rivers, lakes, estuaries, oceans are still complex mixture of unicellular and multicellular organisms that are unique to each water body and within each water body the ecological setup is different. Injury or illness disturbs the body’s homeostasis (the state of steady internal conditions conserved by living things). Optimal functioning for the organism depends on several variables, such as body temperature and fluid balance; the concentrations of sodium, potassium, and cal© Springer Nature Switzerland AG 2021 R. Chandrappa, D. B. Das, Environmental Health - Theory and Practice, https://doi.org/10.1007/978-3-030-64480-2_3

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cium ions; or pH of extracellular fluid. These variables should be kept within certain pre-set limits (homeostatic range) and need to be regulated despite changes in the environmental conditions. Alteration or pollution of water body could lead to epidemics, floods, and other incidents, which may affect health of individuals. The term “disease causative agent” refers to the any agent such as toxic chemical and biological pathogens that causes disease. Disease could be communicable disease or noncommunicable disease or injury, which can be further subcategorized. The disease causative agent is part of the environment. The natural (animal attack, natural disaster, etc.) and anthropogenic activities (industrial activity, waste management, etc.) can cause sickness. Disease causative agents present in the environment can cause sickness in a healthy person. Over the period of time, disease causative agents such as an infection-­causing organism or toxic substance will be released to the environment, which in turn will cause disease in a healthy person. Even healthy people contribute to disease causative agents through air/water/noise/soil pollution (Fig. 3.1). Further human activities can alter the quantity of disease causative agents. In other words, anthropogenic activities can either increase or decrease the quantity of disease causative agents such as pathogens or toxic substances in the environment. Many of the causative agents can be prevented from entering the environment by adopting a proper waste management approach and other good practices discussed in the subsequent chapters.

Disease Causative agent

Healthy Person

Sick Person

Fig. 3.1  Health and environment

3.2  General Biology

97

Fig. 3.2  Pristine natural environment

Human activity has affected the nature changing pristine environment (Fig. 3.2). Alteration of the environment for human benefit (Fig. 3.3) and urban settling with improper planning (Fig.  3.4) have direct impacts on environmental health. The increase in temperature is due to greenhouse gas (GHG) in the atmosphere, and it has been a concern due to associated disasters and other diseases. Physiological systems of animals, namely muscle and neural function, the cardiovascular system, and metabolism, are sensitive to environmental disturbances such as changes in pH, temperature, humidity, water flow, oxygen level, and wind speed. Ocean acidification has a strong negative effect on the structural properties of shells and skeletons of many marine invertebrates. Exposure to chemical pollutants causes change in the gut microbiome and is linked to changes in metabolism, problems with the immune system, as well as neurological and behavioral issues.

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Fig. 3.3  Alteration of environment for human benefit

3.2  General Biology Biology is the study of life. All living things are collectively known as organisms. Living beings are different from non-living beings by seven characteristics explained in Fig. 3.5. All living things are made up of microscopic structures called cells. Some organisms have single cell and are called unicellular organisms. Organisms made up of multiple cells are called multicellular organisms. Figure 3.6 shows an illustration of the complex arrangement of chemicals that makes up an organism. Atoms combine to form the molecules. Small molecules bond together to form larger molecules and these larger molecules form organelles of cells that perform specific activities. These organelles form the cells. Some simple organisms are made up of single cell, which are called unicellular organisms, while others are made up of many cells that are similar in nature. In complex organisms, cells form tissues, which make their organs. The organs form organ systems, which in turn make complex multicellular organisms including the humans.

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Fig. 3.4  Urban settling with improper planning Nutrition

Respiration

Movement

•Organisms obtain raw material for energy and growth

•Organisms break down food within their cells to release energy

•Organisms are abile to move in some way without outside help

Fig. 3.5  Characteristics of living beings

Growth

Reproduction

Sensitivity

•Organisms are capable of removal of toxic substance, waste products of metabolism as well as substances in excess from an organism

•Orgnaisms have abilit to produce new individual organisms

•Organisms have ability to respnd to stimuli

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Fig. 3.6 Illustration showing complex arrangement of chemicals that makes an organism

Subatomic particle

Atom

Molecule

Macromolecule

Organelle

Cell

Tissue

Organ

Organ System

Complex Multicellular Organism

Cells may be prokaryotic or eukaryotic cells. Eukaryotic cells have a nucleus that contains deoxyribonucleic acid (DNA) whereas in prokaryotic cells, the DNA is not encapsulated in a nucleus. DNA is the cell’s genetic material that contains many genes. Genes are the basic physical as well as functional units of heredity.

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Most of the living organisms are unicellular. Complex organisms contain millions of cells. Humans are made up of about 70 trillion cells. These cells need a certain pH range of extracellular fluids, temperature, concentration of mineral ions, as well as glucose in the extracellular fluid. The cells, as part of the organism, interact in ways that keep internal environment relatively constant, in spite of the ­changing external environment. The upholding of a stable internal environment by an organism is called homeostasis. Sometimes homeostatic imbalance can occur due to which cells may not obtain everything they need, or toxic wastes may build up in cells resulting in disease. Table 3.1 summarizes the types of movement into and out of the cell. In biological taxonomy (classification of biological organisms), a domain, also empire or super-kingdom, is the highest taxonomic rank of organisms. It comprises of Archaea, Bacteria, and Eukarya in three domain classifications. Kingdom is the second highest taxonomic rank, which is divided into groups called phyla. Some textbooks list six kingdoms (Animalia, Plantae, Fungi, Protista, Archaea/ Archaebacteria, and Bacteria/Eubacteria) while others list five kingdoms (Fungi, Plantae, Animalia, Protista, and Monera). The description of each of the term is given in Table 3.2. Taxonomic classifications have changed over years and likely to change in the future. Among the non-living beings, viruses are complicated assemblies of molecules that replicate only in living cells of other life forms. Requirements of Complex Multicellular Animals Lives of complex multicellular organisms depend upon the water, oxygen, food, heat, and pressure described in Table 3.3. As evident, the quantities and qualities of water, oxygen, food, heat, and pressure are important for health of humans. In a nutshell, health and un-health are not phenomena that occur only to humans. Health and un-health are associated with all living beings.

3.3  Microbiology Microorganisms play a major role in spreading infectious diseases. Understanding of microorganisms is more important to medical and public health professionals than carnivores, which may attack humans. A microorganism is an organism that is invisible to the naked eye, and is microscopic (visible only with a microscope). Study of microorganisms is called microbiology. Microorganisms may be unicellular organisms or multicellular. Some multicellular organisms are microscopic. But some unicellular organisms are visible to the naked eye. Due to the invisibility to the naked eyes, it is hard to understand their movement and character by common man. Over the millions of years humans have been able to stay away from or kill carnivores to protect themselves. It is only after the invention of microscope and discovery of microorganisms that the medical practitioners

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Table 3.1  Movements of substance into and out of the cell Process Characteristics I. Passive (physical) processes A Simple Molecules, atoms, or ions move diffusion from higher concentration to lower concentration B Facilitated Molecules travel across the diffusion membrane from a region of higher concentration to one of lower concentration through channels or by carrier molecules C Osmosis Movement of water molecule from less concentration to higher concentration region D Filtration Smaller molecules are forced to move across by virtue of pressure II. Active (physiological) processes A Active transport Carrier molecules move atom, ions, or molecules through membranes from regions of lower concentration to regions of higher concentration B Endocytosis 1. Pinocytosis Engulfment of liquid droplets by membrane from surroundings

2. Phagocytosis Membrane engulfs solid particles from surroundings 3. Receptor-­ mediated endocytosis

C Exocytosis D Transcytosis

Source of energy Molecular motion Molecular motion

Exchange of carbon dioxide and oxygen in the lungs Glucose movement through a cell membrane

Molecular motion

Distilled water entering a cell

Hydrostatic pressure

Molecules leaving blood capillaries

Cellular energy

Movement of different atoms, ions, and amino acids through cell membranes

Cellular energy

Membrane-forming vesicles comprising large particles dissolved in water Engulfing of bacterial cells by membranes of white blood cells Cell removing cholesterol-containing low-density lipoprotein (LDL) particles from its surroundings Protein secretion

Cellular energy

Engulfment of selected molecules Cellular combined with receptor proteins energy by membranes

Expelling vesicle-containing particles (or chemicals) Transcellular transport of macromolecules across cells

Example

Cellular energy Cellular energy

Insulin crossing a cell

were able to relate diseases with microorganisms and invent new effective treatment procedures and knowledge to cure diseases by killing the disease-causing microorganisms. However, microorganisms are not always associated with diseases. They live within human body and even on surface of human body. They are essential for the making of foods such as bread, beer, wine, cheese, yogurt, and other fermented foods. Spirulina (biomass of cyanobacteria) can be consumed by humans/animals.

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Table 3.2  Description of domains and kingdoms of living organisms Term Archaea/ Archaebacteria Bacteria/ Eubacteria Eukarya Animalia

Plantae

Fungi Protista Monera

Description Archaea/Archaebacteria comprises of group of prokaryotic organisms that have different molecular characteristics making them different from bacteria and eukaryotes Bacteria/Eubacteria term is used to describe and distinguish prokaryotic bacteria from the archaebacteria Eukarya includes organisms with cells that contain membrane-bound organelles and a nucleus Animals are eukaryotic multicellular organisms that obtain nutrition from organic sources; cells of animal are characterized by absence of rigid cell wall observed in fungi and plants Plants are multicellular eukaryotic organisms characterized by:  (1) Photosynthetica nutrition  (2) Cells with cellulose in their walls  (3) Absence of nervous system Fungi are living organisms with cell walls containing chitin; they digest organic matter before absorbing Protists are eukaryotic organisms that do not qualify as plant, animal, or fungus Monera refers to group of prokaryotic organisms that typically reproduce by asexual reproduction

Photosynthesis: Process by which green plants as well as some other organisms use sunlight to make nutrients from water and carbon dioxide

a

Table 3.3  Requirements of complex multicellular animals Factor Water

Characteristic A chemical substance Food Various chemical substances Oxygen A chemical substance Heat A form of energy Pressure Force per unit area

Description Water is required for a variety of metabolic processes, regulating body temperature, and management of substances within organisms Food is substances that provide necessary nutrients to organisms; nutrients supply energy as well as building blocks of cells Oxygen is used in the process of releasing energy from food for metabolic processes Heat released by metabolism and surrounding environment partially controls the rate of metabolic reactions The atmospheric pressure on terrestrial animals plays an important role in breathing; organisms inside water are subjected to hydrostatic pressure; heart action in humans and other complex multicellular organisms produces blood pressure, which makes blood flow through blood vessels

Food-borne infections or intoxication are caused by pathogenic microorganisms that include bacteria, viruses, fungi that may not cause food spoilage. The major factors that contribute to food-borne diseases are as follows: 1. Allowing long time gap between preparation and consumption of food 2. Contaminated cooking utensils or cooking place

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3. Cross-contamination by contaminated food 4. Eating/drinking raw food from unsafe sources 5. Food handling by infected persons 6. Improper storing 7. Inadequate cooking 8. Inadequate reheating 9. Using of food ingredients from unsafe sources Bacteria Bacteria are single-celled protists that feed on soluble food. Although they may form chains as well as clusters, they are independent organisms. The structure of a typical bacterium is given in Fig. 3.7 and description of the bacterium structure is given in Table 3.4. Bacteria occur in many shapes, which include spheres (coccus), round-ended cylinders (bacillus), helically twisted cylinders (spirochetes), and curved. They also join together to form diplos, staphylos, streptos, etc. (Table 3.5). Chain of infection (Box 3.1) comprises of reservoir (Fig. 3.8) mode of transmission and susceptible host. Infection enters susceptible host through portal of entry and leaves reservoir through a portal of exit. Box 3.1 Microorganism and Infection Penetration of an organism’s body tissues by germs (microorganism/parasite/ fungi), their multiplication, and the reaction of host tissues to the infection-­ causing germs and the toxins produced by them is called infection. The diseases caused by germs are called infectious diseases. All communicable diseases are infectious, but not all infections are communicable.

Cytoplasmic membrane DNA

Ribozomes

Fig. 3.7  Structure of a typical bacterium

Cell wall Flagella

Pilus(plural: pili)

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Table 3.4  Description of bacterium structure Structure Cytoplasmic membrane Cell wall Capsule

Cytoplasm Plasmids Flagella Nucleoid Pili Ribosomes

Description Cytoplasmic membrane regulates transport of food into and waste products out of cell Cell wall is a rigid wall composed of polysaccharide that surrounds the cytoplasmic membrane Some species of bacteria have capsule made up of polysaccharides outside cell wall; they keep the bacterium from drying besides protecting from engulfing by bigger microorganisms Cytoplasm is a gel-like matrix present inside the cell membrane; it contains nutrients, water, wastes, enzymes, gases, and cell structures Plasmids are extrachromosomal genetic structures present in many strains of bacteria Flagella (singular, flagellum) are sting-like structures present in some bacteria that provide a means of locomotion Nucleoid is a region in the bacteria cell where DNA is localized Pili (singular, pilus) are small hair-like outgrowths present in many species of bacteria that assist in attaching to other cells/surfaces Ribosome is an organelle where biological protein synthesis occurs

Protozoa Protozoa are single-celled organisms that reproduce by binary fission. Protozoa ingest solid organics for food. Since protozoa are larger than bacteria by one to two orders of magnitude, the protozoa diet includes bacteria and colloidal organics. Most of protozoa are strict aerobes (organism able to live only in the presence of free oxygen). Like heterotrophic bacteria, they obtain both energy and material for growth and reproduction from the same organic food source. Algae Algae are autotrophic (organism capable of make its own food from inorganic nutrients using light [photosynthesis] or chemical energy [chemosynthesis]), photosynthetic organism. A portal of entry is the place through which microorganisms get into susceptible host such as the respiratory tract, the skin, the gastrointestinal tracts, and mucous membranes. A portal of exit is the place from where microorganisms leave the host. Virus Viruses are small intracellular parasites that contain ribonucleic acid (RNA) or DNA genome bounded by a protein coating. They replicate only inside the living cells of organism. They are characterized by a long co-evolution of virus as well as host. Propagation of viruses depends on host cells supplying the complex metabolic as well as biosynthetic machinery of cells (Gelderblom 1996). Viruses spread disease by cell lysis or disruption of healthy homeostasis. Cell lysis is the breaking open that leads to death of the cell. In multicellular organism, death of many cells affects the whole organism. Disruption of homeostasis (the state of steady internal conditions conserved by living things) can affect health of individuals.

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Table 3.5  Major types of shapes and groups of bacteria Shape Sphere shaped

Term in microbiology Pictorial depiction Coccus

Sphere-shaped bacteria arranged in pairs

Diplococci

Sphere-shaped bacteria arranged in chains Sphere-shaped bacteria arranged in clusters

Streptococci

Intermediate shape between spherical and elongated Rod shaped

Coccobacillus

Rod-shaped bacteria arranged in pairs

Diplobacilli

Staphylococci

Bacillus

Rod-shaped bacteria arranged in chains Streptobacilli Filament shaped

Filamentous

Curved

Curved

Spindle shaped

Fusiform

Spiral form

Spirochete

Dangerous diseases by viruses affecting humans include Marburg virus diseases, Ebola, Rabies, AIDS, Smallpox, Hantavirus pulmonary syndrome (HPS), Influenza,

Fig. 3.8  Chain of infection

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Dengue, Rotavirus infection, severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), and Coronavirus disease 2019 (COVID-19). The reservoir of infectious agents is the place where the agent usually lives, grows, and multiplies, such as humans, animals, lakes, and soil. An infectious agent may affect in many ways. Infection may be transmitted directly—through direct contact (Fig. 3.9) or droplet spread—or indirectly—which may be air borne; vehicle borne, e.g., through food, water (Fig. 3.10), blood, handkerchiefs, bedding, plates, or surgical scalpels; and vector borne (e.g., through mosquitoes, fleas, and ticks). Some species of insects such as mosquitoes are vectors. But not all mosquitoes are vectors. Mosquitoes like other insects play important role in ecosystem; some of them are as follows: (a) Many mosquitoes drink flower nectar, plant sap, and fruit juices. Hence, they help in pollination of some plants. (b) Mosquito larvae consume detritus in water and act as food to insect predators such as fish and frog. Susceptible host is the organism (including humans) that gets disease. Knowledge of the portals of exit/entry and modes of transmission is essential to prevent spread of disease. As discussed, all living organisms grow and reproduce. Each organism has its own nutrition requirement to survive and live, which is different from others, and so also for pathogens. Pathogenic bacteria may have one or more of the following characteristics:

Fig. 3.9  A waste picker with insufficient personal protective equipment exposing herself for direct transmission of infection

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Fig. 3.10 Water overflowing due to accidental damage to water supply line exposing public water supply to microbial contamination

1. They have optimal growth temperature to match with the body temperature of the host. Hence, the pathogenic bacteria of human have optimum growth temperature of around 35–37 °C. 2. They may have capsules to prevent the bacterial cell from being phagocytosed (bacteria getting enveloped and destroyed) and adhere to host cells. 3. They may generate materials that are toxic to their host. 4. They may have enzymes such as DNAase (capable to denature DNA) and coagulase (capable to clot blood). 5. They may possess antigen (substance that induces an immune response in the host body). 6. They may have flagella. 7. They may have resistance to antibiotics (a substance that destroys or inhibits the growth of microorganisms). Infection and disease are not recent phenomena. Diseases make living organisms weak, making them vulnerable to predators or death, eliminating weaker organisms from the ecosystem. Examples of intervention to reduce or eliminate infectious and parasitic diseases in human beings are given in Table 3.6.

Malaria

Intestinal nematode infections

Diarrheal diseases

Respiratory infections

Microorganisms

Causative agent Caused by many viruses and microorganisms; viral pathogens include rhinoviruses, influenza virus, respiratory syncytial virus, parainfluenza virus, mumps, human metapneumovirus, measles, adenovirus, and corona viruses;. the most common bacterial agent is Streptococcus pneumonia, Mycoplasma pneumoniae, Legionella, Coxiella burnetii, Chlamydia spp., Haemophilus influenzae Caused by many viruses and microorganisms, which include Rotavirus, Escherichia coli, Cryptosporidium, and Shigella Nematode egg/larvae

Anopheles mosquito

Soil

Water, food, contact secretions of infected people

Fever, tiredness, vomiting, besides headaches

Passage of three or more loose/liquid stools each day

Mode of transmission Symptoms Air, contact secretions of Runny, stuffy nose and infected people sneezing, fever, muffled speech, difficulty in breathing, laryngotracheitis (croup), drooling and stridor, tachypnea, stridor and cyanosis

Table 3.6  Examples of intervention to reduce or eliminate infectious and parasitic diseases in human beings

Vector-breeding places (stagnant water); infected people

Contaminated soil/water/food; infected person

Contaminated water/food; infected person

Major reservoir Contaminated air; infected person

(continued)

Use of wastewater; manure with eggs of nematode Vector control

Proper waste management; proper sanitation

Required environmental intervention Reduce air pollution; improve ventilation in living places; ensure proper housekeeping

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Causative agent Microorganisms

Microorganisms

Microorganisms

Filarial worms

Trachoma

Schistosomiasis

Chagas disease

Lymphatic filariasis

Table 3.6 (continued)

Wide range of mosquitoes

Schistosomiasis is caused by parasitic worms; people are infected due to contact with infested water during fishing/ recreational/agricultural activity or other reasons Triatomine bug Swelling at the infected region, fatigue, rash, fever, body aches, headache, eyelid swelling, nausea, diarrhea or vomiting, loss of appetite, enlargement of liver or spleen, and swollen glands Most cases are symptomless; the disease causes long-term damage to the lymphatic system (system of thin tubes and nodes distributed throughout the body)

Mode of transmission Symptoms Eye infection Water, contact with secretion of eyes/nose/ throat of infected people

Vector control

Vector control Vector-breeding places (stagnant water); infected people

Proper excreta management; safe agricultural practices; safe water supply

Contaminated water/soil; infected people

Major reservoir Crowded unhygienic human habitat; water pollution; infected people Contaminated water; infected people

Required environmental intervention Proper sanitation

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Sand flies

Mosquito

Mosquito

Protozoa of the genus Leishmania

Dengue virus

Japanese encephalitis virus

Leishmaniasis

Dengue fever

Japanese encephalitis

Source: Baron (1996) and WHO (1990, 2016, 2019a)

Mode of transmission Black flies

Causative agent Onchocerciasis Onchocerca volvulus (parasitic worm) (river blindness)

Major reservoir Water resource management projects (particularly dams); infected people Fever, loss of appetite, low Infected people/ Vector control; dogs/cats/rodents control of dogs/ blood counts, malaise, or cats/rodents; night sweats; eruption of proper solid waste skin sores weeks/months management after the person is infected High fever, headache, rash, Infected people/ Management of and muscle and joint pain monkey mosquito-breeding places Mosquito Infected people/ Management of pigs/birds mosquito farm animals; personal protection

Symptoms Skin nodules as well as itching may develop; eye infections may result in vision damage

Required environmental intervention Vector control

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3.4  I nterrelation Between Environment and Human/Animal Health Humans coexist with Human cells reside Mechanobiology of pathophysiology. Etiology, which is many factors such as: • • • • • • •

the environment in a complex, interdependent relationship. in mechanically rich and dynamic microenvironments. cells has major roles in human physiology and the cause of an abnormal condition or disease, depends on

Emotional stress Free radicals/inflammation Genes Microorganisms Nutritional stress Radiation Toxins

An idiopathic disease is a disease with an unknown cause or mechanism. The interface between humans and the environments can also be a source of diseases. Apart from diseases originating from animals, human–wildlife conflict has resulted in injury and death of humans due to animal attacks. Human–animal conflict can damage livestock, crops, and houses apart from injury/death of humans resulting in psychological trauma as well as adverse effects on food security (FAO 2010). Effect of human exposure to endocrine disrupting chemicals (EDCs) has been well documented (Kelley et al. 2019; Meeker 2012; Takahashi et al. 2004). Exposure to EDCs (e.g., brominated flame retardants [BFRs], polychlorinated biphenyls [PCBs], phthalates bisphenol A [BPA], pesticides, and herbicides) found in consumer goods, personal care products, food, drinking water, and other sources may adversely impact child development (fetal growth, neurodevelopment, pubertal development, early reproductive tract development, and obesity). Examples include Niassa National Reserve in Mozambique where Nile crocodiles killed 57 people, spotted hyenas killed 4, lions killed 34 and injured 37, and leopards injured 9 in 30 years prior to 2007 (Begg et al. 2007). Human–elephant conflict caused death of 1713 humans between 2015 and 2018 in India (Ganesh 2019). As per WHO (2019b), 4.5–5.4 million people are bitten by snakes every year, out of which 1.8–2.7 million develop clinical illness, and about 81,000–138,000 die after the bite. Anatomy and immune system vary from species to species. Hence, there are many common features among different species. Biologically the humans are just one among many species, so some of the diseases that may be contracted by animals can also be contracted by humans. International classifications of animal and human diseases (WHO 2019c) follow different thinking. The classifications of diseases are modified time to time to incor-

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porate new innovations. The list of disease classification for the year 2018 adopted by the World Organisation for Animal Health (2019) is given in Table 3.7. For the year 2019, the list includes 117 animal diseases, infections, and infestations. Disease classifications in the humans are elaborate and well researched, which includes psychological disorder, injury, poisoning, or certain other consequences of external causes; the classification of diseases with respect to humans is based on organs while classification of animal diseases is based on species. The negative effects linked with animal husbandry include risk of zoonosis, food-borne diseases, development of antimicrobial resistance, as well as chronic diseases, such as cancers, cardiovascular disease, and diabetes due to excessive consumption of saturated animal fat (EMPRI 2018).

3.4.1  Zoonosis A zoonosis is a disease that is naturally contagious from vertebrate animals to humans. Zoonosis comprises a hefty percentage of all infectious diseases. Cross-­ sectoral collaboration is essential for the human–animal–environment interface as well as improving global health security. Some of the common zoonosis, main reservoir of causative agents, and usual modes of transmission to humans are given in Table 3.8. Human diseases that are newly discovered or those that are increasing either in geographical range or incidences are referred as emerging infectious diseases (EIDs). EIDs have accelerated to more than 300 distinct diseases recorded since the middle of last century with more than 35 new EIDs emerging since 1980 (Kurpiers et al. 2016; Lederberg et al. 2003; Jones et al. 2008), out of which more than 75% of human EIDs are of zoonotic origin (Taylor et al. 2001; Jones et al. 2008; Karesh and Noble 2009). Many of the EIDs (71.8%) begin from wildlife species (Jones et al. 2008), even though several zoonotic pathogen spillovers originate in domestic animals. Even though movement of pathogens between wild animals and humans usually occurs with sylvatic (Jungle) disease cycles (Fig. 3.11), since domestic animals live in close proximity to wildlife in numerous nations they result in the transmission of pathogen from wildlife to domestic animal to human (Fig. 3.12). Examples of wildlife to domestic animal to human transmission include Henipah viruses and rabies infections (Childs et al. 2007; Daszak et al. 2007). Diseases can also spread further from humans to humans through animal host in urban/rural setup (Fig. 3.13). Zoonotic diseases can be transmitted between humans and animal hosts in many ways that include the following: (a) Shared vectors, such as mosquitoes for malaria (b) Indirect contact, such as exposure to feces of rodent (c) Direct contact, through animal bites, tissues, consumption, scratches, body fluids, and excrement (Wolfe et al. 2005)

1. Multiple species diseases, infections and infestations  (a) Anthrax  (b) Bluetongue  (c) Crimean Congo hemorrhagic fever  (d) Epizootic hemorrhagic disease  (e) Equine encephalomyelitis (Eastern)  (f) Heartwater  (g) Infection with Aujeszky’s disease virus  (h) Infection with Brucella abortus, Brucella melitensis and Brucella suis  (i) Infection with Echinococcus granulosus  (j) Infection with Echinococcus multilocularis  (k) Infection with foot and mouth disease virus  (l) Infection with rabies virus  (m) Infection with Rift Valley fever virus  (n) Infection with rinderpest virus  (o) Infection with Trichinella spp.  (p) Japanese encephalitis  (q) New world screwworm (Cochliomyia hominivorax)  (r) Old world screwworm (Chrysomya bezziana)  (s) Paratuberculosis  (t) Q fever  (u) Surra (Trypanosoma evansi)  (v) Tularemia  (w) West Nile fever

2. Cattle diseases and infections  (a) Bovine anaplasmosis  (b) Bovine babesiosis  (c) Bovine genital campylobacteriosis  (d) Bovine spongiform encephalopathy  (e) Bovine tuberculosis  (f) Bovine viral diarrhea  (g) Enzootic bovine leukosis  (h) Hemorrhagic septicemia  (i) Infectious bovine rhinotracheitis/infectious pustular vulvovaginitis  (j) Infection with Mycoplasma mycoides subsp. mycoides SC (contagious bovine pleuropneumonia)  (k) Lumpy skin disease  (l) Theileriosis  (m) Trichomonosis  (n) Trypanosomosis (tsetse-transmitted)

Table 3.7  Disease classification prepared by the World Organisation for Animal Health for the year 2018

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3. Sheep and goat diseases and infections  (a) Caprine arthritis/encephalitis  (b) Contagious agalactia  (c) Contagious caprine pleuropneumonia  (d) Infection with Chlamydophila abortus (Enzootic abortion of ewes, ovine chlamydiosis)  (e) Infection with peste des petits ruminants virus  (f) Maedi-visna  (g) Nairobi sheep disease  (h) Ovine epididymitis (Brucella ovis)  (i) Salmonellosis (S. abortusovis)  (j) Scrapie  (k) Sheep pox and goat pox 5. Swine diseases and infections  (a) Infection with African swine fever virus  (b) Infection with classical swine fever virus  (c) Infection with Taenia solium (Porcine cysticercosis)  (d) Nipah virus encephalitis  (e) Porcine reproductive and respiratory syndrome  (f) Transmissible gastroenteritis

(Continued)

6. Avian diseases and infections  (a) Avian chlamydiosis  (b) Avian infectious bronchitis  (c) Avian infectious laryngotracheitis  (d) Avian mycoplasmosis (Mycoplasma gallisepticum)  (e) Avian mycoplasmosis (Mycoplasma synoviae)  (f) Duck virus hepatitis  (g) Fowl typhoid  (h) Infection with avian influenza viruses  (i) infection with influenza A viruses of high pathogenicity in birds other than poultry including wild birds  (j) Infection with Newcastle disease virus  (k) Infectious bursal disease (Gumboro disease)  (l) Pullorum disease  (m) Turkey rhinotracheitis

4. Equine diseases and infections  (a) Contagious equine metritis  (b) Dourine  (c) Equine encephalomyelitis (Western)  (d) Equine infectious anemia  (e) Equine influenza  (f) Equine piroplasmosis  (g) Glanders  (h) Infection with African horse sickness virus  (i) Infection with equid herpesvirus-1 (EHV-1)  (j) Infection with equine arteritis virus  (k) Venezuelan equine encephalomyelitis

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9. Other diseases and infections  (a) Camelpox  (b) Leishmaniosis 10. Fish diseases  (a) Epizootic hematopoietic necrosis disease  (b) Infection with Aphanomyces invadans (epizootic ulcerative syndrome)  (c) Infection with Gyrodactylus salaris  (d) Infection with HPR-deleted or HPRO infectious salmon anemia virus  (e) Infection with salmonid alphavirus  (f) Infectious hematopoietic necrosis  (g) Koi herpesvirus disease  (h) Red sea bream iridoviral disease  (i) Spring viraemia of carp  (j) Viral hemorrhagic septicemia

7. Lagomorph diseases and infections  (a) Myxomatosis  (b) Rabbit hemorrhagic disease

Table 3.7 (Continued)

11. Mollusc diseases  (a) Infection with abalone herpesvirus  (b) Infection with Bonamia exitiosa  (c) Infection with Bonamia ostreae  (d) Infection with Marteilia refringens  (e) Infection with Perkinsus marinus  (f) Infection with Perkinsus olseni  (g) Infection with Xenohaliotis californiensis

8. Bee diseases, infections and infestations  (a) Infection of honey bees with Melissococcus plutonius (European foulbrood)  (b) Infection of honey bees with Paenibacillus larvae (American foulbrood)  (c) Infestation of honey bees with Acarapis woodi  (d) Infestation of honey bees with Tropilaelaps spp.  (e) Infestation of honey bees with Varroa spp. (Varroosis)  (f) Infestation with Aethina tumida (Small hive beetle).

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13. Amphibians  (a) Infection with Batrachochytrium dendrobatidis  (b) Infection with Batrachochytrium salamandrivorans  (c) Infection with Ranavirus species

Note: Reproduced from OIE-Listed diseases, infections and infestations in force in 2019, http://www.oie.int/en/animal-­health-­in-­the-­world/oie-­listed-­ diseases-­2019/ with Permission from World Organisation for Animal Health on 6 February 2020

12. Crustacean diseases  (a) Acute hepatopancreatic necrosis disease  (b) Infection with Aphanomyces astaci (crayfish plague)  (c) Infection with Hepatobacter penaei (necrotizing hepatopancreatitis)  (d) Infection with infectious hypodermal and hematopoietic necrosis virus  (e) Infection with infectious myonecrosis virus  (f) Infection with Macrobrachium rosenbergii nodavirus (white tail disease)  (g) Infection with Taura syndrome virus  (h) Infection with white spot syndrome virus  (i) Infection with yellow head virus genotype

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Table 3.8  Some of the common zoonosis, main reservoir of causative agents, and usual mode of transmission to humans Disease Anthrax Animal influenza Avian influenza Bovine tuberculosis Brucellosis Kyasanur Forest disease Cat scratch fever Cysticercosis Cryptosporidiosis Enzootic abortion Erysipeloid Fish tank granuloma Campylobacter Salmonella Giardiasis Glanders Hemorrhagic colitis Hantavirus syndromes Hepatitis E Hydatid disease Leptospirosis Listeriosis Louping ill Lyme disease Lymphocytic choriomeningitis Monkey fever (Kyasanur Forest disease) Nipah virus infection

Orf Pasteurellosis Plague Psittacosis Q fever Rabies

Main reservoir of causative agents Livestock, wild animals, environment Livestock, humans Poultry, ducks Cattle Livestock Monkey Cats Livestock Livestock Livestock Pigs, fish, environment Fish Livestock Livestock Humans, wildlife Horse, donkey, mule Ruminants Rodents Wildlife, livestock, humans Dogs, sheep Rodents, ruminants Cattle, sheep, soil Sheep, grouse Ticks, rodents, sheep, deer, small mammals Rodents Monkey Bats

Sheep Dogs, cats, many mammals Rats and their fleas Birds, poultry, ducks Cattle, sheep, goats, cats Dogs, foxes, bats, cats

Usual mode of transmission to humans Direct contact, ingestion Maybe reverse zoonosis Direct contact Milk Dairy products, milk Tick Bite, scratch Meat Water, direct contact Direct contact, aerosol Direct contact Direct contact, water Raw meat, milk Food borne Water borne, person to person Direct contact Direct contact (and food borne) Aerosol Consumption of meat, blood transfusion Ingestion of eggs excreted by dog Infected urine, water Dairy products, meat products Direct contact, tick bite Tick bite Direct contact Mosquito Fruits partially consumed by infected bats, food and water contamination by infected bat excreta Direct contact Bite/scratch, direct contact Flea bite Aerosol, direct contact Aerosol, direct contact, milk, fomites Bite (continued)

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Table 3.8 (continued) Disease Rat bite fever (Haverhill fever) Rift Valley fever Ringworm Streptococcal sepsis Streptococcal sepsis Tick-borne encephalitis Toxocariasis Toxoplasmosis Trichinellosis Tularemia Ebola, Crimean-Congo hemorrhagic fever, Lassa and Marburg viruses West Nile fever Zika fever Zoonotic diphtheria

Main reservoir of causative agents Rats Cattle, goats, sheep Cats, dogs, cattle, many animal species Pigs Horses, cattle Rodents, small mammals, livestock Dogs, cats Cats, ruminants Pigs, wild boar Rabbits, wild animals, environment, ticks Rodents, ticks, livestock, primates, bats Wild birds, mosquitoes Monkey and rodents Cattle, farm animals, dogs

Usual mode of transmission to humans Bite/scratch, milk, water Direct contact, mosquito bite Direct contact Direct contact, meat Direct contact, milk Tick bite, unpasteurized milk products Direct contact Ingestion of fecal oocysts, meat Pork products Direct contact, aerosol, ticks, inoculation Direct contact, inoculation, ticks

Mosquito bite Mosquito Direct contact, milk

Source: EMPRI (2018), Public Health England (2013), and Park et al. (2016)

Emergence of zoonotic diseases from wildlife depends on the zoonotic pool, that is, the diversity of wildlife microbes (Morse 1993), impact of environmental change on the occurrence of pathogens in wildlife, and the frequency of the zoonotic pool Fig. 3.11  Sylvatic disease cycle

Humans

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Wild life

Domestic animal

Humans

Fig. 3.12  Wildlife to domestic animal to human disease transmission

with human and domestic animals (Wolfe et al. 2005). As per Taylor et al. (2001), 33% of zoonotic pathogens that have spilled over are transmissible between humans. Infectious diseases are linked to land use changes, habitat fragmentation, and biodiversity loss (Allan et al. 2003; Cleaveland et al. 2007; Gillespie et al. 2005; Gottdenker et al. 2014; Keesing et al. 2006; Maganga et al. 2014; Salzer et al. 2007; Cottontail et  al. 2009; Young et  al. 2014). Construction and broadening of truck roads in forests increased access of bushmeat hunters to wildlife in Cameroon, which is the origin of several emerging virus/diseases that includes Ebola, HIV/ AIDS, monkey pox, and Marburg viruses (Wolfe et al. 2005). Pathogen spillover from bushmeat (meat from wild animals for human consumption) may happen through consumption. But risks are associated with exposure to feces and body fluids during butchering and handling (Kilonzo et al. 2014; Paige et al. 2014). Ebola virus disease (EVD) epidemic that emerged in West Africa in 2014 and resulted in more than 28,600 cases and 11,300 deaths in Sierra Leone, Guinea, and Liberia (Johnson et al. 1977; Mari Saez et al. 2015; Baize et al. 2014; WHO 2016), transmitted to humans by contact with body fluids of infected wildlife (Leroy 2004; Judson et al. 2016). With the increase in human population, densities, and connections, diseases have spread more easily resulting in devastating outcomes across the world causing hundreds of thousands of deaths annually with some outbreaks becoming pandemics.

3.4.2  Vector-Borne Diseases The word vector in medicine is an organism that does not cause sickness itself but transmits infection by spreading pathogens from one host to another. Vectors can transmit infectious diseases from animals to humans or between humans. Vectors include mosquitoes, ticks, flies, sandflies, triatomine bugs, fleas, as well as some freshwater aquatic snails. Key facts of vector-borne diseases as per the WHO (2017) are as follows: • Over 17% of all infectious ailments are vector-borne ailments, resulting in over 700,000 deaths per year. • Over 3.9 billion people in more than 128 nations are at risk of contracting dengue, with estimated 96 million cases annually. • Malaria causes over 400,000 deaths annually worldwide.

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Many of the vector-borne diseases are preventable through proper environmental management. Some of the common vector-borne diseases are given in Table 3.9. Distribution of vector-borne diseases depends on complex demographic, environmental, as well as social factors. Changes in agricultural practices, lack of reliable drinking water supply, growth of urban slums, and poor solid waste management can result in the spread of the vector-borne diseases (WHO 2017).

3.4.3  I mpact of Poor Environmental Management on Human and Animal Health Environmental health addresses all external factors to a person and all the related factors impacting behaviors but do not include behaviors not related to environment and genetics. Biodiversity comprises of the genetic diversity within species as well as the population richness of other species in an ecosystem. Healthy ecosystems are vital to Table 3.9  Some of the common vector-borne diseases Vector Mosquitoes

Sandflies Ticks

Triatomine bugs Tsetse flies Fleas Black flies Aquatic snails Lice

Disease Chikungunya Dengue fever Lymphatic filariasis Rift Valley fever Yellow fever Zika Malaria Lymphatic filariasis Japanese encephalitis Lymphatic filariasis West Nile fever Leishmaniasis Sandfly fever (Phlebotomus fever) Crimean-Congo hemorrhagic fever Lyme disease Relapsing fever (borreliosis) Rickettsial diseases (spotted fever and Q fever) Tick-borne encephalitis Tularemia Monkey fever Chagas disease (American trypanosomiasis) Sleeping sickness (African trypanosomiasis) Plague (transmitted by fleas from rats to humans) Rickettsiosis Onchocerciasis (river blindness) Schistosomiasis (bilharziasis) Typhus and louse-borne relapsing fever

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Fig. 3.13 Vector transmitted urban/rural disease cycle

the human existence, prosperity, and well-being (WWF 2016). Humans cannot live in isolation from the environment. Early industrial societies frequently discharged waste/emissions from industrial operations directly into the air, groundwater, and water bodies (WWF 2016), the trend that is now being carried out in the developing world. As per Smith et al. (1999), 25–33% of the global burden of disease occurs due to the environmental risk factors. As per the findings of WHO (2016), 23% of global deaths as well as 26% of deaths among the children under five are attributed to modifiable environmental factors. Disease burden linked to the environment varies from country to country. Overall, 9–14% of disease burden is linked to the environment in some developed countries whereas 23–31% in some developing countries, thereby inferring that most of the deaths and disease could be tackled through improvements in the environment in low- and middle-income countries (WHO 2016). The Japanese encephalitis is transmitted by Culex mosquitoes, that nourish on infected pigs, birds, and other mammals, which spread the infection to humans around paddy fields (Fig. 3.14) and irrigation systems. Improper increase in livestock production contributes to land degradation due to overgrazing, erosion, decrease in soil fertility, and desertification. Animal health activities such as vaccination or parasite control programs may lead to land degradation (FAO 1991). Increase in livestock production can also lead to increase in waste, such as manure from feedlots resulting in pollution. Improper disposal of waste from livestock management firms may increase predatory animal species such as hyenas and dogs on land and sharks in sea. The decrease in the population of one species in a locality may lead to unexpected consequences. Disproportionate use of parasiticides and antibiotics can lead to the development of strains of pathogens resistant to the drug used. Poisoning coyotes to control rabies in Mexico led to rise in the population of jackrabbit that became a pest in agriculture (FAO 1991).

References

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Administration of veterinary drugs may result in their presence in edible products of treated animals resulting in health hazards related to toxicity, immunity, and infection. Control of residues of hormones, pesticides, and drugs in milk, meat, eggs, and other animal products can have impact on both animal and human health. Changes to agricultural practices over the year are also responsible for many diseases including cancer (Box 3.2). Box 3.2 Cancer Express Abohar-Jodhpur Passenger train is nicknamed as cancer express due to number of cancer patients traveling in it every day. Cancer patients get on from Bathinda to Bikaner to avail affordable treatment in Bikaner. “Green Revolution” during the 1960s resulted in excessive use of pesticides, insecticides, etc., in southern districts of Punjab, which has made the region as cancer prone belt of Punjab. Bathinda witnessed fast growth in cancer patients and is nicknamed as Cancer capital of Punjab. This is one of the examples where an attempt to bring down the ailment due to malnutrition for some faction of the society has resulted in noncommunicable disease.

Fig. 3.14  Paddy fields

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Hierarchy of controlling ailment due to environmental factors is given in Table 3.10. Kyasanur Forest disease (monkey fever) is an exemplar of ailment of development linked with deforestation in southern part of India (Nichter 1987). In the 1950s, there was a significant increase in the human population in the Sagar taluk of Shimoga district in the Karnataka State of India, which resulted in noteworthy changes in the local ecosystem giving rise to conditions favoring expression of a hidden enzootic process (Boshell 1969), and the disease, which was earlier endemic to Karnataka state, has been detected from neighboring states as well (Chaubal et al. 2018). Theoretically the control of ailment due to the environmental factors may look simple, but in reality the issues such as disasters, institutional capacity, fund availability, skills and knowledge, and corruption of country/community will guide the end results, which are far from satisfactory. Consequently, the subsequent chapter discusses the theory of environmental health issues and established/possible solution along with deviations in practice. The pathogenesis (manner of development of a disease) of many ailments involves host, genetic, and environmental factors. Apart from other health disorders, these factors disturb the innate system besides adaptive immune systems as well as composition of the intestinal microbiota. Epidemiologic and migration studies supporting environmental risk factors for Crohn’s disease (CD) include childhood hygiene, air pollution, breastfeeding, smoking, diet, stress, exercise, seasonal variation, and appendectomy (surgical removal of the appendix; Dam et al. 2013). Although several neurodegenerative (associated with loss of neuronal structure and function) diseases have been linked to the environmental exposures, single environmental factor accounting for a noteworthy number of cases has not been identified. Exposure to pesticides, herbicides, fungicides, organochlorines, ­organophosphates, and carbamates have been linked to Parkinson’s disease (Cannon and Greenamyre 2011). Exposure to lead, mercury, and pesticides have all been cited as potential risk factors for amyotrophic lateral sclerosis (ALS; Johnson and Atchison 2009).

Administrative control Personal protective equipment

Control

Hierarchy of control Elimination/substitution

Pollutants Elimination of pollution source; substitution with less hazardous material

Vectors Elimination of vector-­ breeding places

Wildlife Avoid wandering in region with wildlife; avoid development project in wildlife habitat Use crackers to threaten wildlife

Provide barricade, building, automation

Spray Treat insecticide polluted stream Awareness, training, legislation, signage, planning, impact assessment Use mosquito Gum boots, Respirator, mask, cloth, slipper, shoe, Cloth, vehicle with goggle slipper, shoe, net/repellent protection goggle

Causative agent Occupational hazard Eliminate/substitute hazardous technology/procedure/substance

Table 3.10  Hierarchy of controlling ailment due to environmental factors

Respirator, mask, cloth, slipper, shoe, goggle

Immunization

Virus/microorganism/pathogen Destroy material contaminated with virus/microorganism/pathogen

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Part II

Introduction to Environmental and Medical Sciences

Chapter 4

Introduction to Environmental Sciences

Abstract  Environmental health literacy should integrate perceptions from both environmental and health literacy to ensure informed choices, improve quality of life, reduce health risks, and protect the environment. In this context, the term “environment” means a space surrounding a microbe, or neighborhood of house, or the village/city where we live, or the planet earth along with space surrounding it. The overall human health can be affected due to adverse changes in the different components of the environment and human health. Interaction of biological communities with their physical environment changes the environment that in turn can affect the health of the human beings. In addressing the above, this chapter discusses the fundamentals of environmental science and the relation of the environment to human health.

4.1  Introduction The word “environment” is new in quite a lot of languages. In French language, its beginning comes from the verb “environner” terming “Environnement.” Equivalent words were formed in other languages: “Paryavaranam” in Telugu, “vide” in Latvian, “Parisara” in Kannada, “Miljö” in Swedish, “Meioambiente” in Portuguese, “Medioambiente” in Spanish, “Al biah” in Arabic, etc. The expenditures for environmental management are multitiered and assured forecasts of future events are difficult. But the risks in the future as well as the related costs can be minimized and eliminated by selecting suitable preventive measures (Nicholas 2003). Global environmental issues are related to economic prosperity, human health, and social well-being. The human behavior has array of impacts on the atmosphere, biodiversity, water, oceans, and land, resulting in serious irreversible environmental degradation threatening human health (UN Environment 2019). Rapid development, though overall continuous reversion, has been the reason for many of health issues linked with environment. The built environment has an impact on the prevention and containment of disease. Cities create job opportunities to survive. With more than half the world’s population living in cities, cities with a high concentration of urban poor are potentially more vulnerable than those that are better resourced, less crowded, and more equal. © Springer Nature Switzerland AG 2021 R. Chandrappa, D. B. Das, Environmental Health - Theory and Practice, https://doi.org/10.1007/978-3-030-64480-2_4

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4.2  Micro- and Macro-Environment The term “environment” means a space surrounding a microbe, or neighborhood of house, or the village/city where we live, or the planet earth along with space surrounding it. Health of human body can be affected by microorganisms when recipient body is favorable for microorganisms to live and multiply. On the other hand, human health can be affected by changing climate or changing constituents of air/ water/food. Understanding the microenvironment is essentially important for professionals working in Environmental Health field. In case of glioblastoma (GBM), the most common and most aggressive brain tumor, GBM cells coexist with normal non-­ neoplastic cells constituting a complex and dynamic tumor microenvironment (TME) (Simon et al. 2020). The human gastrointestinal tract has a microenvironment for divergent physiologic processes; the dysbiosis (also called dysbacteriosis—microbial imbalance or maladaptation) of this microecology has a strong connection with the development of inflammatory bowel disease (IBD; Yan and Li 2020). In the absence of any fresh air, the CO2 concentration in a vehicle interior can increase above the ambient level. When the vehicle heating, ventilating, and air conditioning system is operating in recirculation mode, very little to no fresh air is ingested into the cabin interior. The transient CO2 diffusion from vehicle cabin depends on the microenvironment that depends on wind speed outside the vehicle cabin, the air temperature inside the vehicle cabin, and the dimensions of the diffusing holes (Stitnimankarn et al. 2020). Ecological health is a term that is used differently in different contexts. In medical sciences, ecological health refers to medical sensitivity due to exposure to synthetic chemicals in the environment. In the context of urban planning, ecological health refers to the “greenness” of cities, which includes composting, recycling, as well as energy efficiency. The health of ecology reflected by productivity, organization, as well as resilience that characterize sustainability in the earth’s ecosystems is extremely important to human health. Transformation of healthy ecosystems to pathological conditions is often irreversible. The breakdown of ecosystems is generally favorable to an augment in human pathogens, scarcity of potable water, reduced crop yields, recycling of toxic substances, compromised food supplies, and air pollution, all of which augments human health vulnerability. Addressing the human health from an ecological perspective depends on the social, ecological, and biophysical determinants (David 2002).

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4.3  Physical and Biotic Environment

4.3  Physical and Biotic Environment The term environment refers to everything that is around us, which includes living and non-living things. Several organisms together make communities. Communities and their physical environment make the ecosystem. Energy and mass can neither be created nor destroyed. Hence, the organisms interact with each other as depicted in Fig. 4.1 to get their energy/food. Energy moves life. Energy flows through different levels in an ecosystem. In the first level, primary producers utilize solar energy to generate organic material through photosynthesis. Herbivores eat plants as food to get energy for the metabolic activity such as breathing, digesting food, growth of tissues, blood circulation, as well as body temperature maintenance. Carnivores feed on the herbivores and get energy. Decomposers reduce wastes and dead organisms and release the energy into the environment. Interactions between organisms happen for nutrition and habitation though mutualism, parasitism, commensalism, predation, amensalism, and competition. Parasitic infections, caused by protozoan parasites and intestinal helminths, are among the most prevalent infections in developing countries. As against protozoan parasites in developed countries, intestinal parasites cause a noteworthy mortality and morbidity in endemic (native to particular people or country) countries (Haque 2007). Interactions among the organisms depicted in Fig. 4.2 are also the basis of food cycle. A simple food cycle is shown in Fig. 4.3. The nutrients in the form of elements are consumed by producers (e.g., plants and some microorganisms) capable of converting nutrients into their body mass. These producers are consumed by primary consumers (e.g., herbivores—animals that eat plants). Secondary consumers (e.g., frogs, lizards) consume primary consumers. Tertiary consumers (e.g.,

Mutualism

Commensalism

Parasitism

Amensalism

Mutualism is an interaction between two or more species, for mutual benefit.

Commensalism is an interaction wherein one organism is benefited while other organism is neither benefited nor harmed.

Parasitism is an interaction between organisms in which one organism benefits and other is harmed. The parasite obtains food as well as shelter from the host.

in which the one organism has a negative effect on another, while other organism species is unaffected

ex: Mutualistic relationship between fungi and algae that form lichens. The photsynthesizing algae provides nutrients to fungi while gains protection in return.

ex: Remora (type of fish) living with a shark. Remoras eat food left out by shark while the shark is not affected in the interatction.

ex: Tape worm living in the intestine of humans

Amensalism is an interactoin

ex: Herd of elephants walking on plants may harm plants

Fig. 4.1  Different types of interaction among the organisms

Competition

Predation

Competition is an interaction between organisms for same resource

Predation is a relationship between organisms in which the one orgnism kills another organism for food.

ex: Competition for worms by birds

ex: Humans killing animals for food

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Nutrients

Producers

Primary consumers

Decomposers

Quartenry consumers

Secondary consumers

Tertiary consumers

Fig. 4.2  Food cycle

snakes) consume secondary consumers. Quaternary consumers (e.g., hawks, eagles) consume tertiary consumers. But the food cycle is not always simple. Carnivores eat meat, herbivores eat plants, and omnivores eat both. An example of a complex food cycle is shown in Fig. 4.3. Some species of the plants capable of surviving using light energy and elements in nature are carnivores and trap insects. On the other hand, some people eat deer, snakes, insects, and birds making the food cycle a web. In some circumstances, animals such as pythons, tigers, panthers, and lions eat humans during human–animal conflicts. Humans also consume microorganisms in yogurt and other sources. One-third of fish captured from the oceans in the world is used for animal feed (Telegraph 2008) to enhance milk production (Atwal and Erfle 1992). Hence, anthropogenic activity has altered energy/nutrient cycle that existed in the natural environment. The biosphere is the global ecological system combining all living beings as well as their relationships. Pictorial representation of the linking between biosphere and organisms is given in Fig. 4.4. Humans as organisms have kept some animals in the world free (Fig. 4.5) and others in captivity (Fig. 4.6), benefitting themselves in both the cases. Domination of humans has resulted in the extinction of many species as well. On the other hand, close proximity to different animals has resulted in transmission of some of the diseases originally observed only in animals.

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Nutrients

Pitcher Plant

Insect/ Deer/

Bacteria

sheep/ goat

Frog/Lizard/

Humans

Tiger

Snake

Fig. 4.3  Humans in the food web Fig. 4.4  Linking between biosphere and organisms

Organisms Communities Ecosystems

Biosphere Urban ecosystem imports food and energy from outside its boundary and generates wastes. Some of the urban settling import water from long distance. Megacities are to some extent not dependent on their surroundings for fuel, food, water, as well as other materials. With growth of cities, the import of energy and material into cities increased. As per O’Meara (1999), half of 20,000  tons of food that enters New York City is wasted before it is sold.

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Fig. 4.5  Photos of some captive animals

Even though megacities in many developed nations appear to have resolved the economic and health problems, rapid growth in the developing world has resulted in shortage of basic social services and infrastructure, and pollution (Ethan et  al. 2000). Demand of food and water has depleted ground water and surface water sources around urban bodies of developing countries, forcing village dwellers to migrate away from villages. The release of untreated and partially treated wastewater and solid waste has impacted quality of water and air.

4.4  Climate Change The term climate refers to the average weather conditions over a long duration of time (typically averaged over 30 years). Climate is never static. Earth has changed from being a global snowball to warmer planet in the past few billion years. Global climate changes depend on Milankovitch cycles (deviations in axial tilt, eccentricity, as well as precession of the earth’s orbit that result in cyclical changes in earth’s climate), aerosols, increase in greenhouse gases (GHGs) in atmosphere, and deforestation. More energy from the sun is entering than exiting the top of the earth’s atmosphere resulting in radiative imbalance since at least about 1970. Global mean

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Fig. 4.6  Photos of some free animals

s­ urface temperature (GMST) has increased since the end of nineteenth century with a warming of 0.65–1.06 °C over the period 1880–2012, about 0.69–1.08 °C over the period 1901–2012, and about 0.49–0.89  °C over the period 1951–2012 (Stocker et al. 2013). Climate change will affect health of humans due to the following: • Varying weather patterns (humidity, temperature, precipitation, extreme events, and sea-level rise) • Changes in the quality of the environment • Changes in food production • Changes in human settlements • Changes in the economy (Chandrappa et al. 2011) Human health is sensitive to shifts in climate change and weather patterns directly by the following (Smith et al. 2014): • Changes in temperature and precipitation • Occurrences of heat waves, droughts, floods, and fires The climate change can indirectly affect health by the following (Smith et al. 2014): • Ecological disruptions

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–– Crop failures –– Shifting patterns of disease vectors • Social responses to climate change –– Displacement of populations due to climate change induced disasters Health outcomes depends on complex interactions among the direct and indirect effects of climate change besides social dynamics, such as access to health services, economic development, and population demographics (Watts et al. 2015). Over 220 million additional exposures to heatwaves (with each exposure defined as one person aged 65 years or older exposed to one heatwave) occurred in 2018 compared with a 1986–2005 climatological baseline higher than ever previously tracked. Vulnerability to extremes of heat continues to increase among older populations throughout the world, with the African, South-East Asia, and Western Pacific regions seeing a raise in vulnerability of more than 10% since 1990, with people older than 65 years old becoming increasingly vulnerable. Overall, Europe remains the most vulnerable to heat exposures, due to its aging population, high prevalence of diabetes, cardiovascular and respiratory diseases, and high rates of urbanization (Watts et al. 2019). Seasonal change in temperature is likely to cause bronchitis, goiter, eczema, glaucoma, adrenal ulcer, peptic ulcer, and herpes zoster (Tromp 1963). Variations in ambient temperatures can be linked to heart failure as well as cerebrovascular accidents (Persinger 1980). Ambient ultraviolet levels as well as maximum summertime day temperatures are related to the occurrence of cataracts and non-melanoma skin cancers in the eye (van der Leun et al. 2008). The health effects of wildfires include direct thermal injuries and chronic respiratory symptoms (Black et al. 2017). The global economic burden per person affected by wildfires is more than 48 times higher than that by floods and twice that by earthquakes (Doerr and Santín 2016). Many neglected tropical diseases (NTDs) are likely to be affected by climate change over the seasonal, annual, and decadal terms (Booth 2018).

4.5  Pollution of the Environment Along with the word “environment” the word “pollution” took importance too. Since the late eighteenth century, the world has seen significant changes in agriculture, mining, energy production manufacturing, and transportation. The current century saw tremendous changes in the service sector such as the health care, software, education, communication, pest control, entertainment, waste management, advertisement, and event management, which has increased demand for energy, manufactured products, and transportation. The industrial revolution changed quantity and constituents of wastes and associated pollution. With time, while some countries invested and brought down pollution level in their environment others still have to catch up. Since pollutants do not

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respect political boundaries, the pollutants spread to other countries from countries of origin. The word “pollution” is usually associated with air, water, noise, and soil even though the words thermal pollution, light pollution, radiation pollution, and land pollution also occur in media and literature. The definitions of various types of pollution are given in Table 4.1. Since all the components of the environment are interconnected, pollutants may change media—air to water to soil and other ways. The pollution issue is further complicated as pollutants that enter the environment do not remain the same. The chemical reaction in the environment among the pollutants and other chemicals in nature would end up in complex hazardous compounds that are often not monitored or remain undetected. Water pollution can occur from numerous sources (Figs. 4.7, 4.8, 4.9, 4.10, 4.11, 4.12, and 4.13), which include the following: • • • • • •

Defecation in riverbed Washing cloth/vehicle/vegetable/animal Throwing dead animals in water body Industrial discharges Discharge from urban body Urban/rural/mining/forest/agricultural runoff

Table 4.1  Types of environmental pollution Sl. no. 1.

Type of pollution Air pollution

2.

Water pollution

3.

Soil pollution

4.

Land pollution

5.

Noise pollution

6.

Light pollution (photo pollution) Radiation pollution (radioactive pollution or nuclear pollution) Thermal pollution

7.

8.

Description Presence of substances in the atmosphere at concentrations greater than their usual ambient levels that affects biotic and abiotic components of the environment significantly Presence of substances in water bodies at concentrations greater than their usual levels that affects biotic and abiotic components of the environment significantly Presence of substances in soil at concentrations greater than their usual levels that affects biotic and abiotic components of the environment significantly Presence of substances in land at concentrations greater than their usual levels that affects biotic and abiotic components of the environment significantly Propagation of noise with harmful impacts on the human and animal life; conventionally, noise pollution is not linked to damage of abiotic components and species of other kingdoms Excessive and inappropriate artificial light Pollution caused by radioactive materials

The discharge of liquid with higher temperature into natural waters that would cause harm to the environment

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Fig. 4.7  Defecation in riverbed

Fig. 4.8  Man washing clothes in river

• • • • • •

Scrubbing of air pollutants present in air Disposal of solid waste into water body Accidental/incidental material/oil spills from ships/boats Act of terrorism Religious dumping of worship material/ash Accidental and/or intentional disposal of dead animals in water body

Accidental and incidental release of raw and waste materials into the oceans have been causes of concern in recent years (Box 4.1).

4.5  Pollution of the Environment

Box 4.1 Plastic Pollution of Ocean Due to versatility of plastic, their uses have increased and have occupied many aspects of life. Non-degradability and durability of plastics and buoyancy have become a threat to the environment and make them disperse over long distances. Recreational fishing and boats account for nearly 52% of all the solid wastes dumped in the US waters (UNESCO 1994). In 1975, nearly 23,600 tons of artificial packaging and 135,400 tons of plastic fishing gear and substances were discarded into the sea by fishing boats/ships (Cawthorn 1989; DOC 1990). As per an article published by Horsman (1982), merchant ships discard nearly 639,000 plastic containers daily across the world. Plastic pellets were seen in non-industrial locations such as Rarotonga, Tonga, and Fiji. In New Zealand beaches, more than 100,000 raw plastic granules/sqm were observed in 1989 (Gregory 1989). As per the work published by Ryan and Moloney (1990), plastic trash in South African beaches has raised in five years. Air pollution can happen naturally due, but not limited, to the following: • Soil erosion • Forest fire

Fig. 4.9  Dead calf thrown in a riverbed during a lean season

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Fig. 4.10  Urban discharge into Hooghly River, near Kolkata (Calcutta), India

• • • •

Volcano Pollen grain from plants and trees Decomposition of organic matter Atmospheric chemical reaction

Anthropogenic air pollution sources (Figs.  4.14, 4.15, 4.16, 4.17, 4.18, 4.19, 4.20, 4.21, 4.22, and 4.23) include the following:

Fig. 4.11  Disposal of solid waste in Hooghly River, Kolkata (Calcutta), India

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Fig. 4.12  Water contamination by regular human activities in urban setting

• • • • • • •

Agricultural activity Particulate matter (PM) resuspension due to poor quality of road Smoking Industry Cracker bursting Mining and quarrying activities Exploration/production of oil/natural gas

Fig. 4.13  Fecal matter is being managed and diverted into a natural lake, which is being used to feed in fisheries

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Fig. 4.14  Land preparation for agricultural activity would loosen the soil particles that would be air borne along with agrochemicals fed to it Fig. 4.15  Poor road condition

• • • •

Cooking Fuel combustion in vehicles (used for air/water/land transportation) Solid waste handling/combustion Construction activity

4.5  Pollution of the Environment

Fig. 4.16  Examples of industry near human settlements

Fig. 4.17 Mining

• • • •

Energy production from fuel Road sweeping Religious activity, where worshiping material are burnt and dust is smeared Painting and varnishing

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Fig. 4.18 Cooking

• • • • • • • •

Riots Rocket launching Laboratory activity Bomb testing Drilling bore well Practicing use of war weapons Terrorism Wars

In some situations, anthropogenic activity is likely to contribute to air pollution after several years. Entry of disintegrated paint after few years into the air is often associated with entry of heavy metals, present in the pigments of paints, in the air. Air pollution occurs due to many anthropogenic activities of varying magnitudes and pollutants. Some activities such as lighting candle may not cause significant health hazard immediately but the data are not available to prove beyond doubt that it will not affect health.

Fig. 4.19  Fuel combustion in vehicles

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Fig. 4.20  Waste handling/combustion

Venting and leakage during the extraction, transportation, and processing of natural gas result in emissions of pollutants and GHGs. Many sources intentionally vent gases, like depressurization of equipment before maintenance, vented storage tanks, dehydrators, and oil/gas extraction wells when accumulated liquids are removed after hydraulic fracturing. Solid waste is one of the most challenging source of air pollution, especially in the developing countries where sufficient funds are not allocated for waste management or strict enforcement is not made or, in many cases, laws with respect to waste management do not exist. Often, the waste reduction is done by open burning at source or dump yard. Demolition of buildings and earthwork activities such as excavation and piling generally pose air pollution risks than construction and dragout (trucks dragging out trucks). In order to affect health, pollutants need to reach recipients (Fig. 4.24). And the human activities would often bring them to the proximity of pollutants either in road side or in multistoried buildings, as pollutants spread out by momentum, dispersion, convection, and complex atmospheric phenomena. Port of entry and concentration of pollution determine health impacts due to air pollution (Fig. 4.25).

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Fig. 4.21 Material handling at construction site

Fig. 4.22  Diesel generator at a construction site for electric generation

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Fig. 4.23  Road sweeping

Not all particles in the air have the same properties. Some of the particles may be pathogenic resulting in infection. Other particles may be radioactive resulting in cancer in the recipient. Chemistry of particle determines the health of recipient. While some may be carcinogenic, others may not. Particles such as acid mist may be highly reactive and react with cells of body, damaging cells and tissues they are associated with. The health impact also depends on recipient organ of human body. For example, hot particles may kill biological cells and damage tissues. While respirable particles may enter the lungs and get absorbed affecting the cells in the immediate vicinity, the same particles may not harm the skin the same way if they fall on nail/skin. The chili powder in small quantity, which may not irritate skin/tongue, will irritate if it enters the eyes. Similarly, asbestos, which do not affect the skin in small quantity, may cause asbestosis if they enter the lungs. Biological characteristics also determine extent of health impact based on the recipient organs and environmental conditions. While pollen grains do not multiply, the bacteria/fungi will multiply depending on the temperature, humidity, and nutrient supply at the portal of entry and subsequent location it moves to within the

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Fig. 4.24  People exposed to pollutants

Physical • State of matter (solid/liquid/gas) • Size • Shape • Temperature

Chemical • Reactivity • Radioactivity

Biological • Bacteria • Virus • Fungal Spores • Pollen grains

Fig. 4.25  Examples of physical, chemical, and biological characteristics of pollutants, which define their impacts on health

human body. As discussed in Chap. 3, not all microorganisms are pathogenic in nature. Outdoor and ambient air pollution has been attributed as one of the major causes of death (Ostro 2004; WHO 2015a, b, c). Health of children (WHO 2005), food, and

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water are affected by air pollutants (Chandrappa and Kulshrestha 2016). Ambient air pollution is the cause for about 4.2 million premature deaths worldwide due to their ailments including heart disease, stroke, chronic obstructive lung cancer, pulmonary disease, as well as acute respiratory infections (WHO 2018a). Conventionally sulfur dioxide (SO2), particulate matter (PM), nitrogen dioxide (NO2), and ozone (O3) are measured in the ambient air worldwide. But the particulate matter could contain microbes as well as toxic substances. Overall, 143 million chemicals have been registered since 1800s (CAS 2018), which are not completely understood by the scientific community. Any chemical registered/unregistered in Chemical Abstracts Service (CAS) registry can enter the environment and human body. But not all chemicals are analyzed in the water/air/soil samples collected. Some gases such as SO2 cause irritation, while gases such as CO and acetylene cause asphyxiation. Nasal allergy may be caused due to pollens and pollutants that can remain on skin/respiratory/digestive system or enter the blood and can be transported all over the body. Apart from smoking, other causes for cancer include radon, secondhand smoke, asbestos, benzene, formaldehyde, and array of other substances published by International Agency for Research on Cancer time to time. Lead in air, even in low concentration, is toxic, but the organo-lead compounds are still more toxic. They can cause cardiovascular, hematological, gastrointestinal, neurological, renal, as well as reproductive disorders. Lead accumulated in bones can turn into source of exposure afterward in life (UNEP 2010). The lung of infants as well as developing fetus is more vulnerable to damage as a result of lung toxicants. Air pollution on October 26, 1948, besides the River Monongahela, in close proximity to Pittsburgh in United States, resulted in demise of 20 people due to respiratory and cardiac diseases. Exhausts from gasoline and diesel combustion are probably carcinogenic to people (IARC 1989) and children residing around locations with high traffic are more prone to danger of cancer. Air-borne particles can stay in air for several days (Wells and Stone 1934; Wells 1934; Duguid 1946) and, hence, pathogens can spread by dispersion in air. As per Wang and Pinkerton (2007), exposure to air pollution at the time of fetal development as well as early postnatal life can be associated with the following: 1. Behavioral problems 2. Childhood asthma 3. Congenital defects 4. Decreased lung growth 5. Rise in respiratory tract infections 6. Intrauterine as well as infant mortality 7. Intrauterine growth restriction 8. Neurocognitive decrements 9. Preterm birth 10. Very low/low birth weight

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Air pollution can lead to silicosis and asbestosis due to inhaling silica and asbestoses, respectively. PM in air increases risk for cardiovascular diseases (Pope II et al. 2004; O’Neill et al. 2005; Miller et al. 2007; Whitsel et al. 2009; Ursula et al. 2010). Although there was a general consensus that higher air pollution exposure is linked to middle ear inflammation, commonly known as otitis media (OM), which is a multifactorial disease of the middle ear and globally affects more than 80% of children below the age of three years, the evidence for associations with specific pollutants is not consistent (Bowatte et al. 2018). The eye is vulnerable to air pollution leading to eye irritation and persistent discomfort (Bourcier et al. 2003; Schwela 2000; Klopfer 1989; Zhiwei et al. 2016). As per Mancebo and Wang (2015), ambient air pollutants affect skin health by the following mechanisms: • • • •

Beginning of aryl hydrocarbon receptor Changes to skin microflora Generation of free radicals Introduction of inflammatory cascade as well as succeeding damage to skin barrier

Persistent organic pollutants (POPs) can move long distances besides bioaccumulation in animals and humans. Usual POPs in air include dioxins, pesticides, as well as dioxin-like polychlorinated biphenyls. Dioxins in air might bioaccumulate in plants as well as food products (Schecter et al. 2006). In order to eliminate/restrict the production/use of POPs, Stockholm Convention on Persistent Organic Pollutants was signed in 2001. As of February 2019, there are 182 parties to the Convention (United Nations 2019). Old paint is the common source of lead air pollution. Deteriorating paint chips and suspended particles due to natural weathering, remodeling, dry scraping, as well as demolition result in resuspension of paint particles with lead. Lead poisoning in children was reported in 1892 in Australia for the first time (Gibson et al. 1892); after 12 years peeling lead-based paint, lead poisoning was observed in 10 children (Gibson 1904). Even in countries with efforts to control lead, it still exists in soil/dust/house paint. The phenomenon of formation of new pollutants in nature is the basis of the terms: primary and secondary pollutants (Table 4.2). The terms primary and secondary pollutants are usually associated with air pollutants. Pollutants directly released into the environment are called primary pollutants. Pollutants formed in the atmosphere are called secondary pollutants and are due to reaction of primary pollutants with other substances. Pollutants can be natural or anthropogenic (Fig. 4.26). Pollution can happen incidentally (transportation, industry, etc.) or accidentally (oil spill, fire hazard, etc.).

4.6  Solid Waste

153

Fig. 4.26  Classification of pollutants

4.6  Solid Waste Solid waste is a problem associated with solid wastes existing since the prehistoric days. Both the quantities and qualities of the wastes have changed over the years due to the invention of new technologies, products, and services. The waste characteristics depend on income, culture, geographical locations, economy, and situations like disasters. Health impact is one of the consequences of poor solid waste management. Improper solid waste management can lead to the following (Chandrappa and Das 2012): • • • • • • • • • •

Resource depletion Injury Epidemic Fire hazards Air pollution Water pollution Dog nuisance Snake/insect bite Food contamination Generation of GHGs

Table 4.2  Examples of secondary pollutants Sl. no. 1.

Secondary pollutant Acid rain

2.

Ground-level ozone

3.

Nitrogen dioxide formed in atmosphere Particulate matter formed in atmosphere Peroxyacetyl nitrate (PAN)

4. 5.

Description Formed due to reaction of sulfur dioxide or nitrogen oxide with water Formed when hydrocarbons and oxides of nitrogen combine in sunlight Formed due to reaction of nitric oxide with oxygen present in air Solid particles such as sulfates formed from sulfur dioxide and nitrates form nitrogen dioxide in atmosphere Formed when oxidized volatile organic compounds combine with nitrogen oxide

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• • • •

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Problems linked with aviation due to birds flying above dump sites Erosion and stability problems in land fill or waste dump Increase in rodents and vectors Poor aesthetics

The word waste has many definitions. Primarily, it is any matter that does not have an immediate use. However, a substance that is useless to some could be useful to other persons. A vegetarian can find a dead animal useless, but, for non-vegetarian, it is food. Similarly, the excess food leftover in his or her plate may be useless to him or her, but it is useful for piggeries, compost maker, and biogas generator. The old tires may not be useful for the vehicle owner. However, cement kilns may find it useful as fuel. Any waste that is solid can be termed as solid waste. Waste in semisolid form is semisolid waste. The semisolid waste will not have any definite shape and, also, may not qualify to become liquid due to its resistance to flow. Many slurries from industries and waste clotted blood from slaughterhouses may be considered as examples of semisolid waste. Solid waste is not something a developer or city planner thinks of in the early stages of planning. Most often development authorities are different from that of urban bodies. In the developing world, the city grows haphazardly without planning engulfing the villages and agricultural area nearby, catering to the demand of ­housing and development. As people start moving into new area and start generating waste, the local bodies will then gear up to pick the waste either by outsourcing the garbage collection service or recruiting new personnel. The inability to pay salaries to waste collecting personnel or delay in payment to waste collection subcontractors may add to additional burden on public health. The non-identification or non-availability of waste disposal sites near urban bodies often results in disposal of waste in outskirts on common property such as forest, lakes, wetlands, and beaches. Some of the cities have seen sudden population explosion before administrators can cope with the challenge. Delay in the recruitment of new personnel, indenting contractors, locating suitable place for processing disposal, training new personnel, hiring/buying new vehicle, allocating budget, etc. add to mismanagement of waste at the cost of public health. Solid waste can not only cause injury (due to sharp objects, slipperiness, fall of objects, obstruction to movement, and other physical hazard) but also it can lead to air and water pollution (Fig. 4.27) resulting in associated diseases. Air pollution due to poor solid waste management can cause increase in the rates of respiratory tract infections, intrauterine and infant mortality, behavioral problems, childhood asthma, congenital defects, decreased lung growth, neurocognitive decrements, cardiovascular diseases, silicosis, and asbestosis. Water pollution due to poor solid waste management can cause an array of diseases depending on the pollutants it carries, which can be communicable or non-communicable.

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155

Fig. 4.27  Water pollution due to waste discarded next to stream

Schematic diagram of health impact due to solid waste is given in Fig.  4.28. Apart from water-borne diseases, mismanagement of solid waste can also encourage rodents and vectors. The waste can also host snakes and other species such as scorpions, resulting in snake bites and scorpion bites. The animals near waste dump can also attract carnivorous animals such as panther leading to man and wildlife conflict. The hot objects due to burning of solid waste could result in burns. Several published papers on health issues associated with solid waste mainly concern cancer, birth outcomes, snake bite, dog bite, respiratory diseases, as well as annoyance due to improper solid waste disposal (Dolk et al. 1998; Vrijheid 2000; Hu and Shy 2001; Jarup et al. 2002; Rushton 2003; DEFRA 2004; Chandrappa and Das 2012; Ashworth et al. 2014; WHO 2015d; EMPRI 2018a, b). Solid waste can be classified into many types and subtypes. Examples of solid waste categorization and health hazard are given in Table 4.3. Indiscriminate disposal of solid waste can result in biomagnification, wherein chemicals can accumulate in each level of food chain. The chemicals can enter milk through ingestion/inhalation of chemicals by cow/buffalo. The chemicals also find its way into egg of hen/ducks, which consume contaminated food from waste heaps. Figure 4.29 shows cathode ray tube of television disposed on road and Fig. 4.30

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Burns due to hot objects

Air Pollution Combustion and air suspension Solid Waste

Animal bites

Leachet and overflow Biomagnification

Water Pollution

Water borne diseases

Fig. 4.28  Schematic diagram of health impact due to solid waste

shows a view of waste dump site, which are unscientific disposal methods and can lead to health hazards as discussed in Box 4.2. Box 4.2 Case Studies Case: Plague-Like Epidemic in Surat, India, 1994 Surat of Gujarat state, India, grew over the years and increased eightfolds in the four decades leading to poor sanitation conditions that led to an outbreak of plague in the year 1994 claiming many lives (Central Pollution Control Board 2017). Ineffective management of waste led to the obstruction of storm water drains resulting in flooding of some areas of the city. The later corrective action brought back health status and stopped plague. The disease occurrence resulted in 693 cases and 56 deaths. In addition, the country suffered about USD 2 billion in economic losses, which include nearly USD 420 million in lost export earnings. The disease outbreak resulted in cancellation of trips to India by over 45,000 people (UNEP and International Solid Waste Association [ISWA] 2015). Case: Accra, Ghana In Accra, Ghana, drains blocked by wastes resulted in floods in 2011, which resulted in the death of 14 people, and 43,000 were affected, with 17,000 losing their homes. In addition, 100 incidents of cholera were reported a week after the flooding occurred.

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157

Case: Naples, Italy, 1994–2014 Improper solid waste management in Naples metropolitan area resulted in piling up of wastes in the streets leading to breeding grounds for vector-borne diseases. Case: Mysore, India Improper and illegal disposal of hazardous wastes covered by soil led to the death of a boy in Mysore during playing (Star of Mysore 2017). Studies by Ray et al. (2004) revealed that respiratory symptoms as well as lung function reduction were 94% and 52%, respectively, among the rag-pickers as ­compared to 56% and 34% among the controls. The rag-pickers showed a greater prevalence of frequent diarrhea, low hemoglobin and monocyte counts, high circulating eosinophil, unhealthy gums, as well as dermatitis, when compared to controls. Similar studies on rag-pickers revealed that they suffer from mental and physical illnesses. Usual health concerns associated with rag-pickers are: rat bite, dog bite, redness of eyes, backache, accidental injuries, and headache. Many of them suffer

Fig. 4.29  Cathode ray tube of television disposed on road

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Table 4.3  Examples of solid waste categorization and health hazard Sl. no. Type Subtype 1. Municipal solid Metal waste waste Food waste Ash Waste leather Waste rubber Waste glass 2. Electronic End-of-life (EOL) waste electronic equipment End-of-life electronic consumables Rejected electronic components during manufacturing Electronic items damaged during transportation Waste generated due to absolute technology Anatomical waste 3. Biomedical waste Pharmaceutical waste Radioactive waste Waste sharps Soiled waste Ash of incinerated biomedical waste Animal waste Chemical waste Genotoxic waste Pathological waste 4. Slaughter waste Bones Feathers Waste from digestive system

Health hazard May cause injury Hosts pathogen, attracts rodents Heavy metal contamination Hosts infectious fungus Combustible material, may cause injury May cause injury Some metal may be poisonous (mercury, lead, etc.) Some chemicals used in consumables may be toxic (mercury, cadmium, lead, etc.)

Causes infection, toxic Radiotoxicity, injury, and infection

May cause injury and infection; may host rodents and vectors

(continued)

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Table 4.3 (continued) Sl. no. Type 5. Plastic waste

6.

7.

Subtype High-density polyethylene Low-density polyethylene Polyvinyl chloride Polyethylene terephthalate Polystyrene Polypropylene Other types of plastic Hazardous Discarded waste containers Sludge from effluent treatment plant Waste from manufacturing process Contaminated soil Adhesive and Construction and demolition sealants waste Bituminous mixture, coal tar, and tar Cement Concrete, bricks, ceramics, and tiles Gypsum Insulation, fiberglass, and asbestos Metallic waste Paints and varnishes Soil, stones, and dredging spoil Wood, glass, and plastic

Health hazard Carcinogenic; likely to release dioxins and furans when burnt, which are known to be carcinogenic; may result in hormone imbalance and birth defect

Carcinogenic; likely to release dioxins and furans when burnt, which are known to be carcinogenic; may result in hormone imbalance and birth defect; can lead to acute or chronic toxicity; combustible and explosive waste may lead to injury

Sharp object may cause injury; carcinogenic; likely to release dioxins and furans when burnt, which are known to be carcinogenic; may result in hormone imbalance and birth defect; can lead to acute or chronic toxicity; combustible and explosive waste may lead to injury; may host rodents and vectors

(continued)

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Table 4.3 (continued) Sl. no. Type 8. Agriculture waste

9.

Subtype Husk Brawn Straw Stover Skins trimming Cobs Outer peel Fruit trimming Discarded container of agrochemicals Discarded tools End-of-life EOL ships (EOL) vehicles EOL aircraft EOL two/four wheelers

10. Disaster waste

Health hazard Combustion of agrochemicals is likely to result in air pollution related health impacts; residual chemicals in discarded container of agrochemicals may lead to toxicity; may host rodents, vectors, snakes, and other wild animals

Carcinogenic; likely to release dioxins and furans when burnt, which are known to be carcinogenic; may result in hormone imbalance and birth defect; can lead to acute or chronic toxicity; combustible and explosive waste may lead to injury Waste due to wars Likely to release dioxins and furans when burnt, Waste due to strike, which are known to be carcinogenic; may result in hormone imbalance and birth defects; can lead to mutiny, sabotage acute or chronic toxicity; combustible and explosive Waste due to fire waste may lead to injury and spread infection; may accidents host rodents and vectors Waste due to natural disasters

with mild anxiety and mild depression as common mental disorders (Balu et al. 2016). Modern health care facilities generate huge quantity of solid wastes (WHO 2018b). The health impact due to improper disposal of hospital wastes may not just be restricted to health care personnel and people within the immediate vicinity. It can go beyond the immediate vicinity if the contaminated syringes and waste cotton are repacked and sold. The waste cotton may also be used to make toys or ear buds resulting in spread of diseases. Selling expiry drugs to uneducated people would also lead to deceases. Apart from health issues, improper waste management can also lead to disasters. Some of the major disasters due to improper waste disposal are listed in Table 4.4. The solid waste management depends on socio-economic and cultural background of the society. In many parts of India, the chickens and cows are left stray to feed on waste (Fig.  4.31), which becomes source of food (egg, milk, meat) for humans. The waste bones from the zoos will be auctioned in many parts of the world, which finds its way to become bone charcoal or bone powder. Rapidly growing waste from meat shops and food waste have resulted in the increase in street dog population. Apart from slaughtering in slaughterhouses as well as meat shops, animals are also butchered at places of worship and individual

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161

Fig. 4.30  View of waste dump site

residences generating wastes unscientifically. Apart from dog bite, indiscriminate disposal of animal waste is also a leading cause of zoonosis. About 35 million stray dogs live in India, with the biggest reason being open garbage (Singh 2018). Dog bites are the major source of human infection (WHO 2012). In India alone, about 2.8 million people suffer from snake bite every year resulting in about 46,900 death per year (WHO 2018c). Figure 4.32 shows spillage and seepage during transportation of waste. Other hazards due to waste processing are odors, heavy traffic, litter, noise, flies, as well as birds. Waste segregation plays an important role in solid waste management. But segregation may happen in crude and unsafe manner (Figs. 4.33, 4.34, and 4.35). While some countries dump unsegregated wastes, other will segregate to maximum extent. In the spring of 2001, six million cows, sheep, pigs, and goats were slaughtered to control an outbreak of foot-and-mouth disease in the UK. The outbreak started on Burnside farm, Northumberland, where uncooked food leftovers were fed to pigs. As per the regulations, food wastes had to be cooked to sterilize to prevent disease transfer (Erasmus 2018). Feeding animals with food waste is practiced in many places of the world as waste treatment process. A countrywide ban in China on food waste usage as pig feed due to African swine fever epidemic resulted in use of cockroach in food waste management (New York Post 2018). Termites can also be used for waste treatment in order to produce hydrogen and for increasing the soil fertility (Hussein 2014). In many parts of the world, waste management is not a priority and still done crudely (Figs. 4.36, 4.37, and 4.38).

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Table 4.4  Some of the major disasters due to improper waste disposal Incident Aberfan accident

Description Spillage of coal waste

Date 1966

Acerinox disaster

Contamination with radioactive substance Garbage landslide Spillage of caustic waste Burial of electronic hardware

1998

Location United Kingdom Spain

2017 2010 1983

Ethiopia Hungary United States

1991 1972 1992 1987 1990 2008 1932– 1988 2018 2000 1986 2017 1932– 1968 2014 1976

Albania United States Ocean Brazil Ocean United States New Zealand

Addis Ababa Ajka alumina plant disaster Atari video game burial disaster Bajzë Rail Station disaster Buffalo Creek Flood Friendly Floatees Goiânia accident Hansa Carrier Kingston Fossil Plant disaster Mapua contaminated site disaster Maputo Martin County sludge spill Mayapuri Meethotamulla Minamata Bay mercury poisoning Pune Seveso disaster

Contamination with chemical Coal slurry impound spill Flotsam Radioactive contamination Flotsam Coal fly ash slurry spill Toxic waste Garbage landslide Water pollution Radioactive contamination Garbage landslide Cause of Minamata disease Garbage landslide Toxic pollutant

Mozambique United States India Sri Lanka Japan India Italy

Source: Wikipedia (2018), Pappas (2017), Xinhua (2018), and India Times (2014)

The health impact of solid waste management as well as disposal activities is partly understood. Living in the surrounding area of a landfill and incinerator can result in risk for health of people through inhalation, contact with polluted water/ soil, consumption of contaminated food, etc. Contamination of food traded in unsanitary conditions near waste in developing countries causes major health hazards since food is handled and piled on the ground. Municipal solid waste composition is not uniform. While some substances in the waste exist in large quantities, others will be present at extremely low levels (Johnson and DeRosa 1997). But the substances in low quantity can have high health risks. Similarly, the composition of landfill gas will have gases in small quantities, which would cause health hazards. Landfill gases comprise mainly of carbon dioxide and methane, while mercury vapor, hydrogen sulfide, and volatile organic compounds are at around 0.5% (Zmirou et al. 1994). WHO expert group recommended priority pollutants must be defined on the basis of mobility, environmental persistence, bioaccumulation toxicity, and other hazards such as explosivity (WHO 2000).

4.6  Solid Waste

163

Fig. 4.31  Chicken and cow feeding on garbage

Other phenomenon observed with waste dumps or landfill is generation of leachate (Fig. 4.39) due to moisture within the waste and water entering from environment due to precipitation or surface runoff. Waste incineration generates numerous pollutants, which can be classified as organic compounds, particles, gases, and metals (Harrad and Harrison 1996). The construction and demolition (C&D) waste (Fig. 4.40) generation in 40 countries globally exceeded 3.0 billion tons per annum until 2012 (Ali and Ajit 2018) posing new challenge to waste and environmental managers. C&D waste is generated mainly from the following activities (CPCB 2017): (i) Construction of new buildings (ii) Construction of new infrastructure such as over bridges/under bridges/subways, etc. (iii) Demolition of existing, old dilapidated structures (iv) Excavation/reconstruction of roads (v) Renovation of existing buildings (vi) Renovation/installation of water/telephone/internet/sewer pipelines, etc. The developing countries need to develop complete system to utilize C&D waste (Ali and Ajit 2018). As per a case study in Bengaluru (India), approximately 30% of

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Fig. 4.32  Spillage and seepage during transportation of waste

Fig. 4.33  Waste segregation

the C&D wastes are used at a variety of sites for leveling low-lying areas besides land reclamation. Some C&D waste is dumped illegally in or around wastelands, old lakes, roads and highways, and valleys (Venkatesh et al. 2016). Radioactive waste, which is another global challenge, is produced by numerous sources—nuclear power plants, hospitals, universities, and industries. Radioactive waste emits radiation, and hence hazard to the environment and human health. Therefore, it must be managed with special care. Finding appropriate waste disposal

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Fig. 4.34  Waste coconut being dried before being sent for oil extraction Fig. 4.35 Segregated paper and cardboard waste

method is a main challenge for all stakeholders (IRSN 2013). Radioactive wastes in health care establishments are produced due to procedures in various investigative as well as therapeutic practices. Radioactive waste is divided into following categories: (i) Very low radioactive waste (ii) Low radioactive waste (iii) Intermediate radioactive waste

166

Fig. 4.36  Waste being received at collection centers Fig. 4.37  Manual waste segregation

4  Introduction to Environmental Sciences

References Fig. 4.38  Waste storage

Fig. 4.39 Leachate generation from waste dump

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Fig. 4.40 Construction and demolition waste at the site of demolition

(iv) High-level radioactive waste If radioactive waste with radionuclides have a half-life of less than 31 years, it is considered as “short-lived” otherwise the waste will be termed as “long-lived” (IRSN 2013). Radionuclides used in health care facilities comprise of the following: (i) Sealed sources—radioactive substances enclosed in parts of equipment or encapsulated in impervious or unbreakable objects, such as “seeds” pins, or needles. (ii) Unsealed sources—those that are applied directly and normally in liquid form (WHO 2014). Hazardous wastes even in low concentrations have the potential to have a noteworthy and undesirable public health impact due to their toxicological, physical, as well as chemical characteristics (DWAF 1998). Numerous hazardous waste-­ producing industries have moved to the developing nations due to the low management cost as well as non-stringent regulations resulting in the generation of hazardous waste that is mismanaged leading to adverse impact on public health.

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The quantity of waste generated in industries is usually underreported to avoid statutory obligation while urban local bodies overreport to get funding and route it to waste mafia. The waste is often tipped off in virgin environment such as forest, water bodies, estuary, marshes, and beaches. The waste sometimes is buried and covered with a layer of soil. In some cases, waste is burnt openly releasing toxic fumes.

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CB, Barros VR, Dokken DJ, Mach KJ, Mastrandrea MD, Bilir TE, Chatterjee M, Ebi KL, Estrada YO, Genova RC, Girma B, Kissel ES, Levy AN, MacCracken S, Mastrandrea PR, White LL (eds) Climate change 2014: impacts, adaptation, and vulnerability. Part A: global and sectoral aspects. Contribution of Working Group II to the fifth assessment report of the ­intergovernmental panel on climate change. Cambridge University Press, Cambridge, UK and New York, pp 709–754 Star of Mysore (2017) Belavatha mystery fire: hazardous soil to be removed from accident site, June 9, 2017 https://starofmysore.com/belavatha-­mystery-­fire-­hazardous-­soil-­removed-­ accident-­site/. Accessed on 8th Dec 2108 Stitnimankarn P, Siripoorikan T, Thanomkul N, De Silva P, Pungetmongkol P, Staubs J (2020) Transient CO2 diffusion from vehicle cabin micro-environment in hot and humid climates. Int J Environ Sci Dev 11(5):273–277 Stocker TF, Qin D, Plattner GK, Alexander LV, Allen SK, Bindoff NL, Bréon FM, Church JA, Cubasch U, Emori S, Forster P, Friedlingstein P, Gillett N, Gregory JM, Hartmann DL, Jansen E, Kirtman B, Knutti R, Krishna Kumar K, Lemke P, Marotzke J, Masson-Delmotte V, Meehl GA, Mokhov II, Piao S, Ramaswamy V, Randall D, Rhein M, Rojas M, Sabine C, Shindell D, Talley LD, Vaughan DG, Xie SP (2013) Technical summary. In: Stocker TF, Qin D, Plattner GK, Tignor M, Allen SK, Boschung J, Nauels A, Xia Y, Bex V, Midgley PM (eds) Climate change 2013: the physical science basis. Contribution of Working Group I to the fifth assessment report of the intergovernmental panel on climate change. Cambridge University Press, Cambridge, UK and New York Telegraph (2008) One third of fish caught worldwide used as animal feed. https://www.tele.graph. co.uk/news/earth/earthnews/3353985/One-­third-­of-­fish-­caught-­worldwide-­used-­as-­animal-­ feed.html. Accessed on 3 Feb 2019 Tromp SW (1963) Medical biometeorology. Elsevier, New York UN Environment (2019) Global environment outlook 6. Cambridge University Press, Cambridge UNEP (2010) Final review of scientific information on lead—version of December 2010. http:// www.unep.org/hazardoussubstances/Portals/9/Lead_Cadmium. Accessed 19 Jan 2014 UNEP and ISWA (2015) Global waste management outlook, Vienna UNESCO (1994) Marine debris: solid waste management action plan for the wider Caribbean. IOC Technical Series 41, Paris United Nations (2019) United Nations treaties collection, CHAPTER XXVII – ENVIRONMENT – 15. Stockholm Convention on Persistent Organic Pollutants. https://treaties.un.org/Pages/ ViewDetails.aspx?src=IND&mtdsg_no=XXVII-­15&chapter=27&clang=_en Ursula K, Christian H, Dorothea S, Klaus S, Tamara S, Ulrich R, Wolfgang R (2010) Vascular reactivity and endothelial function. Circulation 111:2913–2920 van der Leun JC, Piacentini RD, de Gruijl FR (2008) Climate change and human skin cancer. Photochem Photobiol Sci 7(6):730–733 Venkatesh V, Mohd SA, Abhimanyu S, Jai A (2016) Construction and demolition waste utilisation for recycled products in Bengaluru: challenges and prospects. Published by Deutsche Gesellschaftfür Internationale Zusammenarbeit (GIZ) GmbH, July 2016, Bonn and Eschborn Vrijheid M (2000) Health effects of residence near hazardous waste landfill sites: a review of epidemiologic literature. Environ Health Perspect 108(Suppl 1):101–112 Wang L, Pinkerton KE (2007) Air pollutant effects on fetal and early postnatal development. Birth Defects Res C Embryo Today 81(3):144–154 Watts N, Adger WN, Agnolucci P, Blackstock J, Byass P, Cai W, Chaytor S, Colbourn T, Collins M, Cooper A, Cox PM, Depledge J, Drummond P, Ekins P, Galaz V, Grace D, Graham H, Grubb M, Haines A, Hamilton I, Hunter A, Jiang X, Li M, Kelman I, Liang L, Lott M, Lowe R, Luo Y, Mace G, Maslin M, Nilsson M, Oreszczyn T, Pye S, Quinn T, Svensdotter M, Venevsky

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Yan PG, Li JN (2020) Advances in the understanding of the intestinal micro-environment and inflammatory bowel disease. Chin Med J 133(7):834–841 Zhiwei L, Xiaoyan B, Jianguang Y, Xiaoli Z, Guoying M (2016) The effect of air pollution on the occurrence of nonspecific conjunctivitis. J Ophthalmol:3628762. Published online 2016 May 30. https://doi.org/10.1155/2016/3628762 Zmirou D, Deloraine A, Savinc P, Tillier C, Bouchanlat A, Maury N (1994) Short term health effects of an industrial toxic waste landfill: a retrospective follow-up study in Montchanin, France. Arch Environ Health 49:228–238

Chapter 5

Introduction to Medical Sciences

Abstract  Medical science is a specialty of science that is concerned with the diagnosis, treatment, and prevention of diseases. However, the fundamentals of medical science need to be understood by the environmental practitioners and professionals to come out with effective solutions to present and future health problems due to continuous changes in the environmental setup. Similarly, the effects of the environment on different organs need to be well understood to chart out effective strategies to guide decision makers take the right decisions to protect public health by maintaining the environments. The relationship between the disease causative agent and level of exposure as well as the degree of effect generally occurs in several ways that form the fundamentals of environmental health. In addressing these points, this chapter discusses the fundamentals of medical sciences for environmental practitioners and professionals.

5.1  Introduction Medical science is a specialty of science that is concerned with the diagnosis, treatment, and prevention of diseases. However, the fundamentals of medical science need to be understood by the environmental practitioners and professionals to come out with effective solutions to present and future health problems due to changes in environmental setup. Similarly, the effects of the environment on different organs need to be well understood to chart out strategies to guide decision makers take the right decisions to protect public health by maintaining the environments. Understanding of the environment and human body has a long history. Primitive people suffered from occasional aches, pains, injuries, bleeding, bone breaks, diseases, and contracted infections. The animal and plant diseases are of less interest to primitive man. The shift from a hunter-gatherer to an agricultural regime that occurred from 6000 to 10,000 years ago altered the spectrum of human health and environment. Before agriculture, discrete group of peoples had little contact with other groups. Hence, the infectious ailments did not spread easily. In addition, these early peoples ate wild plants that combated some parasitic infections.

© Springer Nature Switzerland AG 2021 R. Chandrappa, D. B. Das, Environmental Health - Theory and Practice, https://doi.org/10.1007/978-3-030-64480-2_5

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With agriculture activities, the humans were exposed to pathogens, pin worms, tapeworms, hook worms in excrement that were used as fertilizer. The agriculture also decreased the dependence on the wild plants that combated diseases. The development and urbanization brought more infectious disease and malnutrition. Many evidences from preserved bones as well as teeth substantiate these changes. Tooth decay, affected 17% of samples from city residents, 8.7% from farmers, and 3% of samples from hunter-gatherers (David et al. 2007). While changes in the environment where humans live changed their health, some types of illnesses seem inherent to humans. As per the evidence available in fossils arthritis that troubles people today affected our ancestors’ 3 million years ago; Neanderthals that lived 100,000  years ago, and preserved “iceman” who lived 5300 years ago (David et al. 2007). Relationship between the disease causative agents and level of exposure (agent like toxic chemical or biological pathogen) as well as the degree of effect generally occurs in four ways as depicted in Fig.  5.1 (David 2003; Chandrappa and Kulshrestha 2016). The clinical course of an ailment is pictorially depicted in Fig. 5.2. Medical science has three main branches: basic medical sciences, medical specialties, and interdisciplinary field. Medical specialty area branch of medical practice that can be classified further is depicted in Fig. 5.3. Different ways of classifying medical specialties are given in Fig. 5.4. Interdisciplinary medicines involve the science of medicine as well as other disciplines such as the following: • Addiction medicine • Aerospace medicine

S- Shaped

Curvilinear

Linear. No Threshold

Exposure

Linear. Threshold

Response Fig. 5.1  Usual forms of exposure–response relationships

5.2 Anatomy

177

Exposure

Beginning of disese

Symptoms

Therapy starts

Recovery

Recovery with disability

Demise

Fig. 5.2  The clinical course of an ailment

Medical Science

Basic Medical Sceinces

Medical Specialties

Interdisciplinary field

Fig. 5.3  Branches of medicine

• Hospital medicine • Laser medicine • Travel medicine

5.2  Anatomy Anatomy is a specialty of medical science that deals with the body structure of living beings. The anatomy is divided into microscopic (or histology) and macroscopic anatomy (or gross anatomy). Microscopic anatomy involves the use of optical instruments whereas macroscopic anatomy is the examination of organs of a living organism with unaided eyesight. Human anatomy deals with body structure of humans.

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Medical Specialties

Surgical or General Medicine

Organ based or Technique based

Diagnostic or Therapeutic

Age range of Patient

Fig. 5.4  Different way of classifying medical specialties

The whole human body is more than the sum of the parts (David et al. 2007). Organ systems interact in ways to maintain good health. Human body is just the minute component of the environment. The human body interactions with different environmental components are more complex and not fully understood. The morphology, physiology, metabolism, and behavior of an organism is a product of both the genes transmitted from the parents and the environment such as diet, light, humidity, temperature, and local chemicals (Mugerauer 2010). Each organ part works individually and functions together with other organs. The body is a complex machine where innumerable chemical reactions lead to physical change to form a biological entity. The environment hosts human body. On the other hand, human body hosts millions of microorganisms apart from parasitic macroorganisms such as tape worm and round worm. Understanding structural similarities from the microscopic to macroscopic levels of body itself is a great science. Interaction of human and the environment which may lead to changes in complex systems of human body needs different level of thinking. Any change in the environment can affect either part or whole of body. Many substances such as toilet cleaners, agrochemicals, and vector repellents which are used for protecting health and nutrition may turn out to be detrimental to health as they enter the environment. All these can become pollutants if they enter the nature and will kill many species including humans if the quantities exceed more than the desirable limits. The desirable limits can vary depending upon the media (air/water/ food) they enter.

5.3  Physiology Physiology is a specialty of medical science that deals with the functions of living beings and their parts. Living organisms lead healthy life at the optimum environmental conditions, which include abiotic conditions (temperature, humidity, radiation, noise, light, and proportions of different elements and compounds in the media in which organisms exist), different organisms live in different media and have dif-

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ferent tolerance. The same environment cannot support aquatic and terrestrial animals because they live in different media though both will remain alive for short period when their living media are interchanged. In addition to genetic influences, a number of social demographic, behavioral, cultural, race/ethnic, and environmental factors are linked to physical function, disability as well as chronic disease (Link and Phelan 1995;  Fried and Guralnik 1997;  Koukouli et  al.  2002;  Banks et al. 2006; Barabasi 2007; Turrell et al. 2007). Anatomy and physiology discourse how the body maintains life. Physiology deals with the functions of organs, whereas anatomy deals with the structures, or morphology, of organs. Within the same media, different species show different tolerance like some of the microbes demand oxygen for living while others can live without it. Some of the excreta and metabolic waste/byproduct which are not required by a species are food to other living organisms. Alcohol, which is metabolic waste of microbes, is consumed by many humans. Similarly, the excreta of humans are food for many living beings.

5.4  Forensic Medicine and Toxicology Forensic medicine is a specialty of medical science that deals with the application of knowledge of medical scenic to establish facts in legal cases. Forensic medicine is also known as forensic pathology. Toxicology is the specialty of science that deals with study of undesirable effects that occur in living being owing to chemicals. Many pollutants released into the environment by industry, mining, agriculture, transportation, and even by hospitals are toxic in nature and has high health burden on immediate community and international community. The increased use of toxic substances in day to day use as insecticide, insect repellent, paints, toilet cleaners, disinfectants, and others, will also find their ways into the environment. Toxic substances may reach humans by food, air, or water. Radiotoxic substances can even reach humans by radiation. The numbers of potential neurotoxicants in the environment are increasing and pose a risk for humans and the environment (Legradi et al. 2018). Tiny plastic particles generated due to mechanical abrasion, biological degradation, and photochemical oxidation of larger plastic debris result in the formation of microplastics (size range 1 μm to 5 mm) and nanoplastics (size range 1 nm to 1000 nm) are considered emerging contaminants  and toxicants that affect human health (Liuwei et al. 2020). Major toxic causative agent is given in Table 5.1.

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Table 5.1  Major toxic causative agent Health effect Bone damage Carcinogenic (cancer causing)

Cardiovascular Endocrine disruption Kidney damage Liver damage Lung damage Metabolic diseases Negative birth outcomes (low birth weight, low head circumference, intrauterine growth restriction) Neurodevelopment and cognitive function Reproductive effects

Causative agent Cadmium PCBs (polychlorinated biphenyl), dioxins, PAHs (polycyclic aromatic hydrocarbon), cadmium, arsenic, beryllium, chromium Dioxins, mercury, arsenic PBDEs (polybrominated diphenyl ethers), PCBs, dioxins, manganese Lead, cadmium, mercury Nickel, iron, cadmium PAHs, cadmium, arsenic, lithium PBDEs, dioxins PBDEs, PCBs, dioxins, perfluorooctanoic acid (PFOA), PAHs, cadmium, arsenic PBDEs, PCBs, PAHs, lead, mercury, cadmium PBDEs, PCBs, dioxins, PFOA, lead, chromium, mercury

Source: Grant et al. (2013), Chen et al. (2011)

Box 5.1 Toxic Exposures at Workplace A laboratory worker suffered from asthenospermia as well as fertility problems and, he was suspected of exposure to solvents used at work due to a fault of the ventilation system in his laboratory between August 1996 and April 1997. After investigation, it was found that the worker was possibly exposed to 10 or 50 times higher than the permissible exposure limit of chloroform which is spermatotoxic (Chang et al. 2001). Toxicology and environmental science have close relationships. Natural endocrine-­ disrupting chemicals (N-EDCs) and synthetic endocrine-disrupting chemicals (S-EDCs) can interact with endocrine receptors and disturb hormonal balance (Herman et al. 2020). Toxic substance can reach human body from several sources. Study on microbial contaminants and heavy metal content of stale and fresh tomatoes sold in selected markets in Nigeria showed presence of chromium, copper, total heterotrophic bacteria, manganese, zinc, and total fungi (Izah and Aigberua 2020). Studies on metallic contamination in the neighboring water system and farmland from abandoned mines in Korea revealed pollution from Cd, As, and Zn (Lee and Lee 2020).

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5.5  Pathology Pathology is a branch of medical science concerning the cause, origin as well as the nature of disease. It deals with the study of structural and functional alteration within the body connected with diseases. It involves the examination of organs, tissues, bodily fluids as well as autopsies in order to study as well as diagnose disease. Clinical pathology is a branch of medical science concerned with the diagnosis of ailment based on the analysis of body fluid in laboratory. Environmental pathology is the study of ailment caused by exposure to external agents. A number of important terms used in pathology are given in Table 5.2 and stages of diseases are given in Fig. 5.5. Diseases can be localized, disseminated, or systemic (Fig. 5.6). Diseases can be caused due to array of reasons (Fig. 5.7):

Incubation •Intial entry of pathogen into a host and start multiplying

Prodromal •Pathogen continues to reproduce and the host experience signs and symptoms of illness

Illness •Signs and symptoms of ailment are most obvious and high

Decline •Number of pathogen begins to decrease, and the signs and symptoms of ailment begin to decline.

Convalescence •Patient generally returns to normal functions,

Fig. 5.5  Stages of infectious disease

Localized disease

• Affects one part of the body, e.g., eye infection.

Disseminated disease (metastatic disease)

• Spread to other parts. e,g. cancer.

Systemic disease

• Affects the entire body e.g.: influenza.

Fig. 5.6  Categorization of diseases based on the significance of diseases

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Table 5.2  Examples of important terms used in pathology Term Acquired disease Acute disease Chronic condition or chronic disease Clinical disease Congenital disorder or congenital disease Disease Genetic disease

Hereditary or inherited disease Iatrogenic disease Idiopathic disease Incurable disease Medical disorder

Morbidity Primary disease Progressive disease Refractory disease Secondary disease Subclinical disease (silent disease, silent stage, or asymptomatic disease) Syndrome Terminal disease

Definition Disease that begins at some point during lifetime Disease that lasts a short time Disease that persists over long period of time (lasting 3 months or more) Disease that has identifiable clinical signs/symptoms Disease that is present at birth Abnormal condition that negatively affects the normal functioning of the body Genetic disease caused by abnormalities formed in the genome. Genetic disorders may be hereditary or due to mutation (changes to the DNA) Disease inherited genetically Disease caused by medical intervention Disease with no identifiable cause Disease that cannot be cured Medical disorder is the functional abnormality or disturbance which is further categorized into mental disorder; genetic disorder; physical disorder; functional; and emotional and behavioral disorder The condition of being diseased Disease arising spontaneously which is not associated with or earlier disease Disease that is progressing or worsening Disease that resists treatment Disease that follows and results from a previous disease Stage in some diseases before appearance of symptoms

Group of symptoms which consistently occur together, and characterize a particular abnormality/condition Disease that cannot be satisfactorily treated and is likely to result in the death

• Toxins • Physical agents –– –– –– ––

Electromagnetic fields Heat Radiation Force

• Medically induced –– Medicine

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Toxins

Physical agents

Infection

Disease Medically induced

Harmful Lifestyle

Lack/loss of organ capacity

Consciousness (Emotional traumas)

Fig. 5.7  Main causes of diseases

–– Surgery –– Other medical procedure • Consciousness (emotional traumas) • Lack/loss of organ capacity –– –– –– ––

Inherited/acquired Weakness/susceptibilities Disregulation/imbalance Damage/decline/degeneration

• Harmful lifestyle –– Diet –– Substance abuse –– Over work, lack of sleep • Infection Major environmental factors that affect health areas shown in Fig. 5.8. Environmental factors modifiable to enhance public health include the following:

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Accidents/ Occupatinoal Risks Climate Change

Pollution

Inadequate Water and Sanitation

Land Use and Land Cover Changes

Human Health

Chemicals and Radiation

Agricultural Practives

Solid Waste

Man-Animal Conflict

Fig. 5.8  Major environmental factors that affect human health

• • • • • • • • • • •

Pollution Radiation Electromagnetic fields Occupational risks Built environments including major infrastructural and engineering works Man-made vector breeding places Agricultural practices Waste management Man-made ecosystem and climate change Unsafe environment such as safe road/bus stand Safe water and sanitation

The individuals whose health can be affected due to water pollution could be the following: • Someone who is in the vicinity of the water body • Someone who is consuming water pumped from the water body • Somebody who is consuming aquatic organisms (fish/crab/shrimp/water chestnut/lotus tuber)

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• Somebody who is consuming products manufactured by water pumped from polluted water body Alteration of water body can lead to the following: • • • • •

Reservoir-induced seismicity Floods Increase in vector population Wildlife migration to human habitats Shortage of water for drinking and crops, thereby affecting food supply to humans

5.6  Pharmacology Medicines have a significant role in the prevention and treatment of disease in animals and humans. Medicines may also have unintentional effects on the environment. Pharmacology is a specialization of medical science that is concerned with the uses, effects as well as modes of action of medicines. Environmental pharmacology is a branch of pharmacology that is concerned with the entry of drugs into the environment after they are excreted by humans and animals in post-therapy. Even though the side effects on human as well as animal health are generally investigated in toxicology and safety studies, the environmental impacts of the manufacture as well as use of pharmaceuticals are less understood. Some medicines can affect animals and bacteria below the concentrations that are typically used in efficacy and safety tests. Further breakdown products as well as the combination of other biologically active chemicals may have unexpected effects on the environment (Boxall 2004). About more than half of all medicines prescribed, sold, or dispensed inappropriately result in adverse impact on health, and nearly half of all patients do not take them as directed resulting in resources waste and adverse impact on health, wildlife, and ecosystems (Felicity 2017). The medicines have been found in varied concentration in surface water, ground water sewage treatment plant effluents as well as drinking water. Pharmaceutical waste is affecting the nature negatively, as disused medicines are not discarded and/or disposed appropriately (Stal-Timins et  al. 2013; European Environment Agency EEA) 2010). A  global review reported that 631 out of 713 pharmaceuticals tested were observed greater than their detection limits in the environment (aus der Beek et al. 2016). As per Scheytt et al. (2006) up to 16,000 tons of medicines were disposed of every year from human medical care with 60–80% of these drugs placed in normal household waste or flushed down the toilet. Studies published indicate that about 10% of pharmaceutical products were of potential environmental risk in Germany (Küster and Adler 2014).

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5.7  Anesthesiology Anesthesiology is the science as well as practice of giving anesthetics (substances to stop patients feeling pain). Leakage of anesthetic gases from machines, scavenging, and breathing out by patients find their way to atmosphere and are believed to have noteworthy ozone-­ depleting potential resulting in destruction of the stratospheric ozone layer (Nunn 2008). Assuming that nearly 200 million anesthetic procedures are performed every year in the world, Sulbaek et al. (2010) anticipated that the globally inhaled aesthetics emissions will be equivalent to 4.4 million tonnes of carbon dioxide.

5.8  Community Medicine Community medicine is the branch of medicine concerning health care issues affecting entire community. Community well-being focus on the protection, maintenance, as well as improvement of the health status of population groups as well as communities. It deals with the study as well as improvement of the health of biological communities. Goals of community medicine • • • •

Focus shift from treatment of sick Prevention of diseases Promotion of healthiness Quality of life improvement for individuals and groups

Human community is formed by families. Family practices as well as cultures such as alcoholism, smoking, violence, and crime will be easily absorbed by younger members resulting in negative health. Further offspring will also inherit many genetic diseases. There are numerous genetic disease inheritances that include following four modes: (a) Single gene inheritance: These disorders are known as monogenetic disorders (disorders of a single gene). (b) Multifactorial inheritance: These disorders are caused by a combination of environmental factors besides mutations in multiple genes. (c) Chromosome abnormalities: Abnormalities in chromosome can result in disease. (d) Mitochondrial inheritance: This type of genetic disorder occurs due to mutations in the DNA in mitochondria. The health of family members depends on affordability of family to the following: (a) Balanced nutrition

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(b) Good housing (c) Access to drinking water (d) Access to sanitation (e) Medical care (f) Transportation (g) Healthy environment (h) Education Health depends on social structure as well as culture. The routine organization as well as restrictions of daily settings shape our human health. Even though depression has disturbing disabling effects, it is often not recognized by patients or doctors. A community is a small or large social unit who has something in common. An individual may belong to much community depending on something what he/she has common with respect to members of other community. The dimension of the boundary varies from local community to international community. Community participation is core element of healthy community. The legislature, executive, and judiciary wings of the community need to be vibrant and honest if a human community has to be healthy in the current scenario. Corrupt and dishonest community will lead to depletion/misuse of resources which otherwise can be used for education, disaster management, environment ­protection, and treatment to sick people. Poor community support will leave the victim of accident unattended on road. Poor laws and enforcement will lead to pollution and spread of diseases. Community participation in vaccination, health education, research, environment protection is essential for vulnerability to diseases. The cooperation and networking with local and international community are keys to health of individual and all members of community. A community with conflicts will expose the members of community to injury, pollution, poor health care, explosion of epidemics, and food/water availability.

Fig. 5.9  Froth formations in lake due to misuse of the common property for discharge of untreated effluent

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Fig. 5.10  Use of lakes by animals to keep them cool

Fig. 5.11  Use of lakes for disposing solid waste

Sociologists have established that the increase of diseases is influenced by the socioeconomic status of people, other cultural factors, and ethnic traditions/beliefs (White 2002). Culture is not static, and it evolves and passes on through generations. Many good and bad practices followed are also passed on to the next generation in changing the environment. Figure 5.9 shows froth formation in a lake on Bangalore, India due to disposal of wastewater from city. Old belief “dilution is solution of pollution” cannot be continued forever especially when quantity of pollution is beyond assimilation capacity of nature resulting in waterborne diseases. The culture endures and evolves depending on the exposure of the community to new believes, behaviors, and circumstances. In some parts of the world, cattle is reared in the common properties such as grazing land and surface water bodies leading to health and environmental impact. Figure 5.10 shows continuation of letting

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Fig. 5.12  Use of lakes by people to wash cloths

Fig. 5.13  Remains reinforcement idols of clay idols after immersing in water

buffalos to cool themselves in surface water body polluting the surface water body, which affects human and animal health. Some cultures are unaware of germ theory and the impact of chemicals they use (Fig. 5.11). Use of common property such as river, lakes, forest also varies vastly across the culture. Education may help, but beliefs and practices over generations may dominate the behavior (Figs. 5.12, 5.13, 5.14, 5.15, and 5.16).

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Fig. 5.14  People washing cattle in surface water

Fig. 5.15  People washing vehicle in surface water

There can be many cultures within a society. Social inequalities span across cultures. The cultural preference to food, clothing, shelter, nonviolence, and social justice varies widely. Some of the culture and impact on the environment and health are given in Table 5.3. Different individuals and communities have varied footprints. In other words, individuals and communities can affect health of others at different dimensions. A

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191

Fig. 5.16  Remains of worshiping material disposed in surface water body

head of the state will have larger health footprints to extent of his state and outside the state also. Decisions he/she makes may result in a spread/curb of diseases outside the states also. A non-alcoholic, non-smoking person without genetic disorder consuming balanced nutrition cannot lead a healthy life if a drunkard hits him while driving. Drunkard may impact health of few people will small ailment footprint, but shop keeper of alcoholic drinks will have larger ailment footprint and manufacturer will have still bigger ailment footprint to the extent of millions of people. Similarly, a city discharging its untreated sewage into river will affect health of communities downstream of the city. A drug manufacturing industry cannot guarantee health of its customers even if the doctors prescribe correct medicine. Healthy community will have common but differential responsibility to maintain health of communities. An individual shall educate himself not only to keep himself healthy but also others.

5.9  Dermatology and Venereology Skin is the largest organ in general. The functions of skin are as follows: • Protect body from environmental stressors such as pollution, germs, germs, radiation • Regulate body temperature • Receive sensory information Even though skin  serves as a barrier to infection, any break in the  skin  permits entrance of pathogens. Dermatology is the branch of study that deals with all the disorders of the inner mucous membranes as well as outer skin. Venereology (sexually transmitted disease or sexually transmitted infections) deals with disorders transmitted through sexual contact.

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Table 5.3  Example of culture and impact on the environment and health S.No. Cultural practice 1 Burning dead bodies without pollution control equipment to trap pollutants released during cremation 2

Disposing ash in surface water bodies

3

Disposing dead bodies and partially burnt dead bodies in surface water bodies

4

Immersing idols of clay and other worshiping material into surface water Cleaning after defecation in surface water bodies Cleaning cloths in surface water body Injuring to self by beating, pricking during festivals and rituals Sacrificing animals in unhygienic condition in public Cutting trees and plucking leaves of trees for use in religious rituals

5

6 7

8

9

10 11

Processions leading to noise pollution Occupying common property such as footpaths and forest for religious purpose

Impact on environment Release of dioxins and furans from plastic present in clothsRelease of radioactive material if the body belongs to patients who have undergone radio therapyRelease of mercury if the body has traces of mercury amalgamation in teeth Release of dioxins and furans from plastic present in clothsRelease of radioactive material if the body belongs to patients who have undergone radio therapyRelease of mercury if the body has traces of mercury amalgamation in teeth Release of radioactive material if the body belongs to patients who have undergone radio therapyRelease of mercury if the body has traces of mercury amalgamation in teeth Water pollution

Water pollution

Water pollution

Impact on health Non-communicable disease such as metal poisoning, and cancer

Non-communicable disease such as metal poisoning, and cancer

Non-communicable disease such as metal poisoning, and cancer

Non-communicable disease such as metal poisoning, and cancer Communicable disease leading to gastroenteric disorder Spread of diseases

Spread infection and affect psychology Physical and of viewer inducing fear/anxiety physiological disorder

Spread infection and affect psychology Physical and of viewer inducing fear/anxiety physiological disorder. Reduction in carbon assimilation capacity; decrease in oxygen content in atmosphere; increase in solid waste may result in dog/rodent menace, air pollution and vectors Noise pollution

May lead to respiratory, cardiovascular disease, injury, and communicable disease

Hearing impairment and psychological disorder Traffic congestion, damage to wild life Injury to humans due to habitat traffic congestion and negative impact on health of wild life due to loss of habitat (continued)

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Table 5.3 (continued) S.No. Cultural practice 12 Hunting/fishing 13

14

Impact on environment Death of wildlife and loss of biodiversity Affects air and water

Throwing/smearing colored water powder during festival Bursting crackers Water pollution, air pollution, solid waste management

Impact on health Death of wild life Affects skin, eye

May lead to respiratory, cardiovascular disease, and injury

The skin is an important interface between environment and humans; it is an important portal of entry for disease causing agents that include huge array of chemical, physical, and biological agents (Suskind 1977). Even minute quantity of arsenic can lead to skin hardening, organ damage as well as cancer. Arsenic-related skin diseases that affected thousands are briefly discussed in Box 5.2. Box 5.2 Drinking Water and Skin Health Surface water supplies in Bangladesh were contaminated with microbes causing noteworthy morbidity and mortality. During the 1970s, in an attempt to overcome this problem tube wells were inserted to provide safe source of drinking water. Since 1983, thousands of skin lesions due to arsenic were identified in the exposed population (Smith et  al. 2000; Langford and Ferner 2002).

Disease causing agents of sexually transmitted diseases include viruses, bacteria, fungi, and protozoa (Thappa and Sivaranjini 2011). Venereal diseases can also be transmitted by several other ways. To date, modes of transmission of HIV-1 include sexual, percutaneous (through the skin), and perinatal (immediately before and after birth) (Gershon et al. 1990). Children may sustain injuries from discarded needles leading to exposure to blood-borne viruses. The important pathogens in such transmission include hepatitis B virus (HBV), hepatitis C virus (HCV) and HIV (Gerberding 1995; American Academy of Pediatrics 2006). HIV virus that causes AIDS transmitted through sexual contact can be spread through infected sharps in solid waste. Many skin diseases are linked to immunologic genetic and environmental factors. Exposure to environmental influences that affect skin include the following: • Chemicals or infections • Climatic determinants • Such as UV radiation

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5.10  Obstetrics and Gynecology Gynecology is the field of study concerned with the health of the female reproductive systems as well as the breasts. Obstetrics is the medical specialization concerned with pregnancy, childbirth, as well as the  postpartum period. Environmental exposures in the womb can have effects throughout the life. Magnitude of maternal mortality is high in spite of efforts by governments all over the world. Globally, around 830 women die daily due to childbirth/pregnancy complications. In 2015, about 303,000 women died during/following child birth and pregnancy which could have been prevented (Alkema et al. 2016). In sub-Saharan Africa, many nations reduced their levels of maternal mortality by about 50% since 1990 and even greater headway was made in other regions. Between 1990 and 2015, the maternal mortality ratio in the world declined by only 2.3% per year (WHO 2018). Despite improving statistics, every year about 2.6 million are still born besides 2.7 million babies die during first month of life (UNICEF, WHO, World Bank, UN-DESA Population Division 2015; Blencowe et  al. 2016). Premature birth increases the risk of new-born mortality in addition to long-term health problems (Prüss-Ustün et al. 2016). Exposure to chemicals and air pollution are known to increase the risks of premature birth (Ferguson et al. 2013).

5.11  Ophthalmology Ophthalmology is a specialization of medicine which deals with the functions, structure, as well as diseases of the eye. Environmental features such as pollutants, temperature variations, ultraviolet radiations, variable humidity affect various parts of eyes in several ways resulting in disorders such as conjunctivitis, cataract, glaucoma as well as dry eye (Shubhrica 2013). Eye is the most susceptible organ to environmental and atmospheric abuse. Although human eyes are evolved to protect it from foreign objects, they need to remain open for the purpose of vision. It can act as port of entry to respiratory viruses besides acting as primary site of virus replication (Belser et al. 2013). Chronic exposure to pollutants affects the eye from slight irritation to bleeding of retina. Exposure to contaminated water can degrade eye health over the time (Yadav 2019).

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The common eye ailments liked to environment are the following: • Fungal keratitis—an infection of the cornea caused by fungus • Trachoma—infectious disease caused by bacteria • Snow blindness (arc eye or photokeratitis)—loss of vision due to overexposure to the UV rays • Actinic keratopathy (also called  spheroidal degeneration  or  climatic droplet keratopathy)—inflammation of the eye due to prolonged exposure to ultraviolet rays Trachoma linked to poor sanitation is the reason behind visual impairment in about 2.2 million people worldwide (Mohammdpour et al. 2016). Exposure to augmented noise, global warming, flood light sources, intense UV, and infrared radiations too damage human vision (Yadav 2019). Eye infection could be eliminated by environmental measures as well as changes in behavior. While incidences of blindness due to ozone depletion and greater solar ultraviolet radiation have reduced, global warming may turn into a factor in the early onset as well as rapid succession of cataract (Johnson 2004).

5.12  Orthopedics Bones provide support to animal body and protect the body’s organs. Muscles are the only tissue that has the ability to contract and hence move the body parts. Orthopedics is a specialization of medical science concerned with the correction of deformities of bones/muscles. Several environmental toxicants can affect health of bone and muscles directly and indirectly. Endoncrine disruptors, volatile organic compounds, dioxins and dioxin-like compounds, fluoride, fungal toxins (toxins released by fungi), arsenic, boron, cadmium, lead, lithium, iron, strontium, tungsten, and mercury are likely to affect bone health (Smith et  al. 2017). High cadmium exposure will cause bone damage (Agneta et al. 2006). Small quantity of fluoride strengthens bones as well as prevents dental caries, but excess fluoride in water can result in irreversible as well as crippling condition in children called skeletal fluorosis. Fluoride exposure can occur through drinking water, excessive ingestion of toothpaste as well as mouth rinses. Exposures to excessive fluoride to children can result in irreversible dental mottling as well as pitting of enamel.

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Box 5.3 Fluoride and Fluorosis: Case Studies Alteration of water characteristics happen due to natural and anthropogenic activity. Chemicals naturally present in the environment may be triggered by anthropogenic activity leading to deterioration of water quality beyond potable quality. The groundwater in villages as well as its environment in Siddipet area, Medak district, Telangana State, in India are affected by fluoride contamination due to rock–water interaction dominance besides evaporation dominance are reasons for the alteration in the quality of water in the aquifer of the study area, resulting in dental fluorosis of major population living in the villages (Narsimha and Sudarshan 2017). Fluoride poisoning in Northern Africa, the Rift Valley system, in addition to the area extending from Turkey to China due to high fluoride concentrations naturally occurs in the drinking water. This has resulted in skeletal fluorosis as well as associated skeletal abnormalities (Langford and Ferner 2002). Air pollution may have long-term harmful outcomes with respect to bone in exposed pediatric populations (Calderón-Garcidueñas et al. 2013).

5.13  Otorhinolaryngology The ears and nose are sensory organs for hearing and smell, respectively, while the throat acts as a pathway through which fluids and food travel to the esophagus (tube that connects throat and stomach) besides air passes to the lungs. Otorhinolaryngology is a specialization of medicine which is concerned with the diseases of the ear, nose, and throat. Nose provides air for respiration besides serving as the sense organ for smell. It conditions the air by warming, filtering, moistening, cleaning foreign particles before air travels into body. Nose is also the major port of entry for many disease-­ causing agents including SARS-CoV-2, the virus responsible for COVID-19 disease that appeared in China in late 2019 and became a pandemic. Studies in China (Fengying et al. 2016) concluded that air pollutants had health effects on ear, nose, and throat. Brauer et al. (2007) published a link between air pollution as well as ear–nose–throat infections apart from respiratory health outcomes in a large group of children. Diesel exhaust particles can provoke the development of new allergen sensitization when enter nose (Limaye and Salv 2010). Sore throat could be noninfectious or infectious. Noninfectious environmental factors for sour throat include air pollution, temperature, and humidity. Ambient air pollution is a common reason for sore throat beside occupational exposure hazardous chemicals (Renner et al. 2012). Apart from nose and ear is an important sense organ that can be affected by noise pollution and infection.

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197

Noise pollution leads to hearing loss or impairment (Hinchliffe 2002) besides several psychological and physiological effects (Oguntunde et al. 2019). The combination of air and noise pollution is liked to respiratory ailments, tiredness and dizziness (Adetoun et al. 2011; Shendell et al. 2009), high blood pressure (Ebare et al. 2011), cognitive difficulties (Ntui 2009) impact on fetal development (Selander et al. 2019), annoyance and anxiety (Paiva et al. 2019), mental health crisis (Freiberg et al. 2019), sleep disturbance and insomnia (Eze et al. 2018; Freiberg et al. 2019), cardiovascular disorders (Sears et  al. 2018), cardiocerebrovascular diseases (Oh et al. 2019), type 2 diabetes incidence (Thiesse et al. 2018), and medically unexplained physical symptoms (Zock et  al. 2018), myocardial infarction incidence (Bräuner et al. 2018), peptic ulcers (Min and Min 2018), and disruption of communication and retentive ability (Tesoriere et al. 2018).

5.14  Pediatrics Pediatrics is the branch of medical science dealing with children and their diseases. A number of diseases in children are related to unsafe environments. The environment plays important role on children health that is more vulnerable to diseases due to following reasons: • Children consume more food and water in proportion to their weight. • Exposure to certain toxic chemicals can result in irreversible damage, as well as to diseases during adulthood. • Their immunity, digestive system, reproductive systems, and central nervous system are more vulnerable compared to adults. • They are in an active state of growth. • They are more exposed through hand-to-mouth activities due to innocence and ignorance about consequences. • As children have smaller lungs, they breathe more air in proportion to their weight. Child health refers to a state of complete mental, physical as well as social well-­ being and development of fetus as well as from birth of the baby till 5 year of age. The factors that affect the health of children include but not restricted to the following: 1. Age 2. Climate change 3. Corruption in the governance 4. Environment 5. Ignorance 6. Illiteracy 7. Lack of access to maternal and child health services 8. Malnutrition

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9. Poverty 10. Sex 11. Size of the family Contaminated water leads to many diseases that include diarrhea, the second largest child-killer in the world. Nitrate pollution in the water causes the “blue baby syndrome” and increased carbon monoxide in air affects fetal growth as well as compromises organ/muscular development in children.

5.15  Neurology and Psychiatry Neurology is a branch of medical science dealing with disorders of the nervous system. Long-term exposure to ambient air pollution is linked with cognitive impairment as well as cerebrovascular disease (Wilker et al. 2015). Traffic-related air pollution exposure is linked with adverse effects on cognitive, behavior, and psychomotor development in children. Further, it is associated with cognitive decline as well as higher risk of dementia in the elderly (Paula et al. 2018). Box 5.4 Pollution and Neurological Disease Minamata disease a methyl mercury poisoning with neurological symptoms named after it is first found in Minimata city in Japan, during 1956. It was caused by the release of methyl mercury by Chisso Corporation’s chemical factory in the industrial wastewater. Methyl mercury poisoning with neurological symptoms was associated with consumptions of fish and shellfish that contaminated with toxic chemical discharged into the sea (Noriyuki 2006).

The neurodevelopmental effects of childhood due to lead exposure and lost productivity due to lead exposure cost about US$ 1 trillion every year in low- and middle-income countries (LMICs) (Attina and Trasande 2013). This is seven times the entire development assistance given to developing nations each year (OECD 2015). Psychiatry is a specialization of medical science that deals with the study as well as treatment of mental illness, emotional disturbance, as well as abnormal behavior. Environmental psychology is the study of relationship between environments its effects on inhabitants.

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Box 5.5 Pesticide in Modern Agriculture and Health The application of endosulfan by aerial spraying over the cashew plantations in Kasaragod district of Kerala state, India from 1978 (NIOH 2001) was the cause of series of health issues.  The cashew nut trees are primarily in the higher portions while the village houses are located in the valleys. Streams flow with lots of small ponds and tributaries which drain into a nearby river. Households get their water from open wells or “surangas” (tunnel). The use of endosulfan resulted in mass deaths of fishes, bees, birds, frogs, and cows. The endosulfan application also affected large number of diseases related to the central nervous system affecting about 8000–9000 people in Kasaragod district (Joe 2010). In Karnataka state, India application of endosulfan between 1980 and 2000 on 850 ha in Dakshin Kannada affected population in nearly 20 villages of the state (Down to Earth 2017).

5.16  Surgery Injuries or disorders of the body are treated by incision or manipulation with the help of instruments. Life cycle assessment in the United States revealed that production of single-use surgical devices and disposable materials, energy used for heating, ventilation, and air conditionings, as well as anesthetic gases have been major sources of environmental emissions (Thiel et al. 2015). Poor solid waste management and housekeeping may cause spread of infection within the hospital to outside the hospital. Nosocomial is a primary cause of mortality and morbidity in the United States (McFee 2009) and many other countries. Surgery demands high sterile and clean environment as the patient who undergoes surgery may contact nosocomial infection if the equipments and operation theatre are not sterilized and clean. The COVID-19 pandemic forced a radical decline in surgical activity to protect uninfected patients from nosocomial infection. Based on observation made in France, between March 1, 2020 and April 5, 2020, out of 305 patients admitted to digestive surgery departments, 4.9% developed nosocomial infection with SARS-Cov-2 (Luong-Nguyen et al. 2020).

5.17  Pulmonology Pulmonology is a branch of medical science that is concerned with ailments involving the respiratory tract. A variety of microorganisms can cause infection of upper respiratory tract that includes the common cold, acute bronchitis, SARS, COVID-19, influenza, and respiratory distress syndromes. Excessive air pollution from natural (Box 5.6) and artificial (5.6) sources can lead to respiratory illnesses. Over half of

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the world populations now live in cities and the number is increasing (UN 2014). Ninety-two percent of the global population is exposed to unhealthy levels of ambient air pollution, caused primarily by road traffic, industrial emissions, and domestic fuel burning (WHO 2016c) affecting their respiratory system. Box 5.6 Forest Fire and Lung Oxygen generated from forest is good for lungs and the entire body. However, when the same forest catches fire, the reverse could happen. Forest fires in Indonesia during 1997 were associated with a raise in mortality and morbidity and smoke emitted affected the neighboring nations, namely, Malaysia, Brunei, Southern Thailand, and Singapore, besides parts of the Philippines. The forest fire was associated with rise in the many hospital admissions which was associated with respiratory complaints (Langford and Ferner 2002).

In 2012, the deaths of 169,250 children below 5 years were linked to ambient air pollution (WHO 2016c) in addition to 531,190 deaths due to indoor air pollution (WHO 2016a, b). Box 5.7 Industrial Gas Accident and Pulmonary Health Accidental release of Bromine at a chemical plant in Geneva, Switzerland in November 1984 resulted in visit of 91 patients to the hospital with common symptoms of cough, upper respiratory tract irritation, and headache (Langford and Ferner 2002; Morabia et al. 1988). Derailing of freight train in Youngtown, Florida, in 1978 resulted in escape of 50 tons of chlorine spreading on local motorway resulting in death of eight motorists due to pulmonary toxicity and affecting 100 people (Langford and Ferner 2002).

Several viral epidemics such as the severe acute respiratory syndrome coronavirus (SARS-CoV) from 2002 to 2003, and H1N1 influenza in 2009, Middle East respiratory syndrome coronavirus (MERS-CoV) in 2012 have been recorded (Cascella et  al. 2020). Coronavirus disease 2019 (COVID-19) originated from Wuhan, China, and spread quickly to 72 countries causing more than 90,000 confirmed cases beside more than 2946 deaths as of 3 March 2020 (Li et al. 2020).

5.18  Nephrology Nephrology is a branch of medical science, which focuses on the treatment of kidney conditions as well as abnormalities.

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The kidney is vulnerable to environmental pollution as most environmental toxins are concentrated by the kidney in the course of filtration. Long-term exposure to particulate matter PM2.5 (particle size