Environmental & Occupational Medicine
Total Page:16
File Type:pdf, Size:1020Kb
Environmental & Occupational Medicine Jānis Dundurs Environmental & Occupational Medicine Textbook for RSU foreign students Rīga RSU UDK 614.7 (075.8) + 613.6 (075.8) D 56 Dundurs, Jānis. Environmental and Occupational Medicine: Textbook for RSU foreign students. – Rīga: Rīga Stradiņš University, 2014. – 228 p. The book includes all of the most important issues of environmental and occupational medicine. As ecological parts of the environment, the air, water, settlements, as well as food toxicology, safety and quality assurance have been discussed. Some chapters are devoted to work environment and assessment of the effect of environmental risk factors on human body. The textbook has been written for international medical students. Environmental and occu pational medicine is closely related to other branches of environmental science and public health, therefore it may be used by many-branched environmental and public health specialists, envir onmental and work inspectors, ergonomists, ecologists and other interested groups. Head of the Publishing department: Tenis Nigulis Senior editor: Aija Lapsa Editor: Jānis Zeimanis Proof reader: Regīna Jozauska Layout design: Ilze Reitere Cover design: Mikus Čavarts RSU IPN No. 13-305 © Rīgas Stradiņa universitāte, 2014 Rīga, Dzirciema iela 16, LV 1007 ISBN 978-9984-793-62-7 Preface 5 PREFACE For many years, hygiene was a key discipline of preventive medicine with its roots in 2.5-thousand-year long history. In Latvia, Hygiene was one of the courses taught to future doctors since the establishment of the Faculty of Medicine in the early years of our country’s independence. During the years of Soviet occupation, teaching was carried out according to unified programmes that were limited only to some theoretical and practical aspects of hygiene recognized in the Soviet Union. After the restoration of independence, teaching of hygiene experienced significant changes. In the last decades of the previous century, the world’s scientific and technical developments with the expansion of the range of eco-environmental factors had led to the loss of balance between human biological characteristics and the ability to timely adapt to the new urban environmental factors. In reality, at certain stages of life, the speed and unpredictability of ecological changes began to overtake the limits and speed of human body’s adaptive mechanisms. In our era of globalization, indi vi dual health security risk is increasing in the whole society and for each of its members. Health-care tasks have expanded from the medical treatment to maintenance and promotion of health. The latest knowledge on one of the natural sciences ‒ human ecology ‒ has to be taken into account. Human ecology has ceased to be a purely biological science and has gained medically biological and socially hygienic meaning. Due to the effect of interference with the natural environment, human ecology has been regarded as a multi-disciplinary science, based on the maintenance of the harmony between the human health and the environment, which, in turn, is determined by the social aspects of society. Under such circumstance, there exists intersection between methodological approaches to the ecological assessment of the environmental factor, its effects on the human organism and hygienic reasons of preventive measures, i.e., education on the role of environmental factors in the life processes of the human body must be regarded as a conceptually unified ecological and hygienic matter. The object of study in both human ecology and hygiene is anthropoecological system “person- envi ronment” with a human, society, and their health in the centre, taking into 6 Jānis Dundurs. ENVIRONMENTAL AND OCCUPATIONAL MEDICINE account all the various environmental and social factors, environmental exposure (impact) on life processes. Both branches of science have a mutually united funda- mentals ‒ common goal of finding solution to the crisis in the global ecosystem. There exists interconnection between health and environmental issues, the con- cept “environmental health” comprises those aspects of human health, including the quality of life, which are determined by chemical, physical, biological, social and psychosocial environmental factors. Healthy environment is related to the aspects of environmental quality. Environmental Health is a discipline of Environmental science that develops the theoretical and practical foundations to identify, standardize, measure, and control positive and negative environmental parameters (natural, anthropogenic, social), as well as to prevent or reduce their possible harmful effects on the human body. Environmental and Occupational Health should be treated from the position of a structurally systematic approach aimed at multidimensional and objective evaluation of different levels of environmental factors, human health and prediction of public health basing on the significance of the factors, which form life- style of a healthy person. It is very important to provide future medical professionals with the knowledge not only on diagnosing and treatment of diseases and disorders to restore normal func- tioning of human body, but also about harmful risk factors of domestic and work ing environments, their impact on health, as well as reduction or even elimin ation of these factors, thus achieving decrease in mortality and morbidity rates in society. At present, the courses of preventive medicine include Environmental, Occu- pational Health and Medicine emphasizing the specifics of students’ future work environment. The principle of teaching Environmental and Occupational Health is to identify the relationships between human and medically biological, and socially hygienic factors of environment in system “environment-human-society”. The edu- ca tional process takes place based on the structurally systematic approach, which is aimed at versatile, reasoned and objective assessment of the role of environmental factors, evaluation of human health as well as to predict public health basing on the significance of the factors, which form lifestyle of a healthy person. The text-book has been written for teaching environmental and occupational medicine and health to international medical and health care students. The manu- script is based on the author’s twenty-year-experience in work with international students making use of the latest educational and methodical aids, and brochures in both the Latvian and the English languages written in the recent years. Seven chapters of the book include definition and outline of the issues related to pollution of air, water, food, and other environmental components, their impact, identification, assessment and selection of decrease measures. The book is an edu- cational material for reducing the risk, or even prevention of various unfavourable factors in domestic as well as any work, including therapeutic and health-care, environment. Preface 7 I hope that this book will help students to better understand globally increasing environmental pollution problems and health issues related to its maintenance, improvement, and preventive measures in the society as a whole and for each indi- vidual’s health. I also hope that other readers in English will find the book useful. I express my sincere thanks to the Rīga Stradiņš University (RSU) adminis- tration for support, the reviewer Dr. habil. med. professor Maija Eglīte for valuable remarks and advice, the staff of RSU Publishing House ‒ its head Tenis Nigulis, editor Jānis Zeimanis, proof-reader Regīna Jozauska, layout designer Ilze Reitere and especially senior editor Aija Lapsa. Dr. chem. Assoc. Professor Jānis Dundurs Contents 9 CONTENTS INTRODUCTION . 13 Chapter I. HAZARDS AND RISKS . 17 1. Nature and effects of environmental hazards . 17 2. Health risks . 21 Chapter II. AIR AND HEALTH ........................................ 23 1. Air as an environmental factor . 23 1.1. Air chemical composition . 23 1.2. Air physical properties ............................................ 5 2 1.3. Sun radiation .................................................... 5 2 2. Air pollution . 26 2.1. Chemicals as pollutants . 26 2.2. Ionizing radiation and health . 29 2.3. Ozone and ultraviolet radiation . 31 2.4. Sick building syndrome and building related diseases . 33 3. Air quality criteria .................................................... 35 3.1. Air temperature .................................................. 35 3.2. Air humidity .................................................... 37 3.3. Air motion . 40 3.4. Atmosphere pressure . 41 3.5. Indoor air exchange . 43 3.6. Optical electromagnetic wave band . 45 4. Human heat exchange . 48 5. Tasks for students: Seminar “Air as an environmental factor” . 51 Chapter III. WATER AND HEALTH . 3 5 1. Water as an environmental factor ....................................... 3 5 1.1. Significance of water .............................................. 3 5 1.2. Water properties . 55 1.3. Water resources . 57 10 Jānis Dundurs. ENVIRONMENTAL AND OCCUPATIONAL MEDICINE 2. Water pollution . 59 2.1. Chemicals as pollutants . 61 2.2. Microorganisms as pollutants . 63 2.3. Thermal pollution ................................................ 63 2.4. Radioactivity pollution ............................................ 64 2.5. Water-borne diseases . 64 3. Drinking water . 66 3.1. Drinking water quality demands . 66 3.1.1. Microbiological quality . 67 3.1.2. Chemical quality . 67 3.2. Obtaining drinking water . 71 3.3. Protection of drinking water