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  1. 1. Advances in Environmental Health (PbEH5101) Credit hours: 2 By Simachew Dires 1
  2. 2. Course Contents 1. Introduction • Definition of terms • Brief Historical Overview of Environmental Health 2. Hazard, exposure and risk • Biological Hazards • Chemical Hazards • Physical hazards • Methods for monitoring and control of environmental hazards 3. Principles of pollution prevention 4. Concepts and principles in hygiene and environmental Health • Environmental intervention models • The role of environmental health in public health • Promoting Environmental conditions that enhance health of humans and other species. 5. Essential Services of Environmental Health 6. Vector Control 7. Housing and institutional health 2
  3. 3. Course Contents 8. Food safety and human health • Historical review on situation of food hygiene in Ethiopia • Public health importance of food • Factors of food-associated diseases • Food hygiene intervention • HACCP Principles • Standard criteria • Regulatory Mechanisms and Agencies in Ethiopia to Prevent and Control Food Safety • GMO 3
  4. 4. Methods of instruction • Lecture (power point presentation) • Classroom discussion • Individual home work • Group work/Term paper presentation • Reading assignments 4
  5. 5. Definitions of Environment • The word environment is derived from a French word “ environ” which means surrounding or enveloping. • Environment: the total of our surroundings • All the things around us with which we interact: Living things- Animals, plants, forests, fungi, etc. Non-living things - Continents, oceans, clouds, soil, rocks Our built environment - Buildings, human-created living centres Social relationships and institutions 5
  6. 6. 6 What is the environment? The trees, air, & soil around us Our fields, farms & the food we grow Our oceans, lakes, and rivers ALL the places we live, work & play
  7. 7. Definitions of Environment • Scope of Environment: The environment consists of four segments: 1. Atmosphere - implies the protective blanket of gases, surrounding the earth; • it sustains life on the earth; • the atmosphere is composed of nitrogen and oxygen besides, argon, carbon dioxide, and trace gases. 2. Hydrosphere: The Hydrosphere comprises all types of water resources oceans, seas, lakes, rivers, streams, reservoir, polar icecaps, glaciers, and ground water. 7
  8. 8. Definitions of Environment 3. Lithosphere: Lithosphere is the outer mantle of the solid earth. It consists of minerals occurring in the earth’s crusts and the soil e.g. minerals, organic matter, air and water. 4. Biosphere: Biosphere indicates the realm of living organisms and their interactions with environment, viz atmosphere, hydrosphere and lithosphere. 8
  9. 9. Environmental science • Environmental science is the study of the interaction of humans with the natural environment. • It is the study of how humans interact with their environment. • Devoted to studying the impacts humans have on the environment. • Environmental science (or studies) - interdisciplinary studies in natural sciences, including geology, climatology, hydrology, ecology, and their interaction with social sciences such as economics, political science, sociology, anthropology, geography. 9
  10. 10. Environmental science and the issues that it studies are complex and interdisciplinary. • Includes concepts and ideas from multiple fields of study. • By combining aspects of the natural sciences, social sciences, and the humanities, the field of environmental science can cover more concepts and also examine problems and topics from many different points of view. Environmental science cont’d.. 10
  11. 11. Environmental science cont’d.. 11
  12. 12. • A community decides to use coal for electricity, as it is the cheapest source available. (Economics) • The coal must be mined from under the soil. (Geology) • The coal must be transported to the population center by road or rail. (Engineering) • When it is burned at a power plant, air pollution is released. Some of that pollution is converted to acid in the atmosphere. (Chemistry) • This falls as acid rain somewhere downwind. (Meteorology) • The acid stresses plants by affecting their nutrient absorption. (Ecology) • Laws are passed requiring the plant to install pollution scrubbers. (Politics) Environmental science cont’d.. 12
  13. 13. Environmental science cont’d.. Goal of environment science: To understand and solve environmental problems • Ecosystem functions • Air Pollution • Water Pollution • Toxic Chemicals • Climate Change • Resource usage 13
  14. 14. Environmental science cont’d.. • Environmental science helps us understand our relationship with the environment and informs our attempts to solve and prevent problems. • Solving environmental problems can move us towards health, longevity, peace and prosperity • Environmental science can help us find balanced solutions to environmental problems. 14
  15. 15. Major environmental problems 1. Resource Depletion • A great deal of resources are needed to support the human population (~7 billion). Natural Resources are any natural materials that are used by humans water, petroleum, minerals, forests, & animals Said to be depleted when most of the resource has been used up Either renewable or nonrenewable resources Nonrenewable resources take millions of years to be replaced if depleted. (Oil) Renewable resources can be replaced relatively quickly by natural process. (Trees) 15
  16. 16. 2. Pollution Pollution is an undesirable change in the natural environment that is caused by the introduction of substances that are harmful to living organisms. Can also be excessive wastes, heat, noise, or radiation Much of the pollution that troubles us today is produced by human activities & the accumulation of wastes. 17
  17. 17. 2 main types of pollutants: Biodegradable pollutants Can be broken down by natural processes over time Example: newspaper Only a problem if they accumulate faster than they can be broken down Nonbiodegradable pollutants can’t be broken down by natural processes Example: mercury Can build up to dangerous levels in the environment • Pollution, whether in air or water, can move and affect ecosystems far away from the source.
  18. 18. 19
  19. 19. 3. Loss of Biodiversity Biodiversity is the variety of organisms in a given area (in one specific ecosystem). There is: genetic variation within a population A variety of species in a community A variety of communities in an ecosystem Humans need to understand & preserve biodiversity for our own survival.
  20. 20. The organisms that share the world with us can be considered natural resources. We depend on them for: food, the oxygen we breathe, & for their potential economic, scientific, aesthetic, & recreational value. Scientists think that species extinction may cause problems for the human population.
  21. 21. Current Extinctions • Extinction, or the complete loss of a species, is a natural event that can be accelerated by human actions. • Assuming no catastrophic events occur, extinctions normally occur at a pretty slow rate, called the background rate. Normal background extinction rate for mammals is 1 every 200 years. • Scientists believe we may be in the midst of the next major extinction event, due to human influences. 22
  22. 22. • The rate of extinctions is estimated to have increased by a multiple of 50 since 1800, with up to 25 percent of all species on Earth becoming extinct between 1800 and 2100. • Australia has experienced 27 mammal extinctions since 1788, primarily due to the influence of European settlers 23
  23. 23. Species Prone to Extinction • Species that are especially at risk of extinction are those that migrate, those that need large or special habitats, & those that are exploited by humans. • Endangered species-has been identified to be in danger of extinction throughout all or a significant part of its range, & that is thus under protection by regulations or conservation measures • Threatened species-has been identified to be likely to become endangered in the future 24
  24. 24. Biodiversity Loss and Species Extinction: Remember HIPPO • The major causes of extinction today are: • H for habitat destruction and degradation • I for invasive species • P for pollution • P for human population growth • O for overexploitation
  25. 25. Population and Consumption • Developed countries on average have higher incomes, longer life spans, slower growth rate, diverse industrial economies, & stronger social support. • These countries are more economically stable, educated, and have more environmental protections • Developed countries, while smaller in size and growth, consume resources at a greater rate. • About 20% of the world’s population uses 75% of its resources. 26
  26. 26. • This rate of consumption creates more waste & pollution per person than in developing countries. • Developing countries have lower average incomes, simple agriculture-based economies, & rapid population growth. Almost all environmental problems can be traced back to 2 root causes: • The human population in some areas is growing too quickly for the local environment to support. • People are using up, wasting, or polluting many natural resources faster than they can be renewed, replaced, or cleaned up.
  27. 27. Local Population Pressures When the population in an area grows rapidly, there may not be enough natural resources for the everyone to live a healthy, productive life. In severely overpopulated regions, forests are stripped bare, topsoil is exhausted, & animals are driven to extinction. In these areas, malnutrition, starvation, & disease can be constant threats.
  28. 28. Ecological footprint • An ecological footprint is one measurement of a person’s resource use. • Ecological footprints are calculations that show the productive area of Earth needed to support one person in a particular country. Estimates land used for crops, grazing, forest products, & housing Includes the ocean area used to harvest seafood & the forest area needed to absorb the air pollution caused by fossil fuels. • Developed countries have a much larger footprint, reflecting a much larger use of resources. 29
  29. 29. Consumption Trends
  30. 30. Ecological Footprint 31
  31. 31. An ecological footprint is one way to express the differences in consumption between nations.
  32. 32. Ecological footprints are not all equal • The ecological footprints of countries vary greatly. • The U.S. footprint is much greater than the world’s average. • Developing countries have much smaller footprints than developed countries. 33
  33. 33. Environmental Impact (I) = (P)(A)(T) 34
  34. 34. Health • Health: “Health is a state of complete physical, mental, social and spiritual well-being and not merely the absence of disease or infirmity.” • In recent years the statement is amplified to include, “The ability to lead a socially and economically productive life.” 35
  35. 35. Integrated Environmental Health Middle School Project • University of Washington © 2005 36 What is health? Nutritious foods help us stay healthy. Doctors, hospitals & medicines help us get healthy if we’re sick. Regular exercise helps keep us strong and healthy.
  36. 36. Definitions of Environmental Health Environmental health has been defined in many ways: • Some definitions make reference to the relationship between people and the environment, evoking an ecosystem concept, and • others focus more narrowly on addressing particular environmental conditions. • Some focus on abating hazards, and others focus on promoting health- enhancing environments. • Some focus on physical and chemical hazards, and others extend more broadly to aspects of the social and built environments.
  37. 37. Definitions of Environmental Health • Environmental health is the branch of public health that is concerned with all aspects of the natural and built environment that may affect human health. • Public Health is defined as “the art and science of preventing disease, prolonging life and promoting health through the organized efforts of society” (Acheson, 1988; WHO). • Other terms referring to or concerning environmental health are environmental public health, and public health protection / environmental health protection.
  38. 38. Definitions of Environmental Health • “Environmental health - comprises those aspects of human health, including quality of life, that are determined by physical, chemical, biological, social and psychosocial factors in the environment. • It also refers to the theory and practice of assessing, correcting, controlling, and preventing those factors in the environment that can potentially affect adversely the health of present and future generations” (World Health Organization [WHO], 2004). 39
  39. 39. Definitions of Environmental Health • “Environmental health is the discipline that focuses on the interrelationships between people and their environment, promotes human health and wellbeing, and fosters a safe and healthful environment” (National Center for Environmental Health).
  40. 40. Environmental Health… • Environmental health and protection refers to protection against environmental factors that may adversely impact human health or the ecological balances essential to long-term human health and environmental quality, whether in the natural or man-made environment. – National Environmental Health Association • Environmental Health is the field of science that studies how the environment influences human health and disease. • In the aggregate the definitions make it clear that environmental health is many things: an interdisciplinary academic field, an area of research, and an area of applied public health practice.
  41. 41. Integrated Environmental Health Middle School Project • University of Washington © 2005 42 Environmental Health? The study of how the environment affects your health. Food Air Water Sunlight Noise Soil
  42. 42. Integrated Environmental Health Middle School Project • University of Washington © 2005 43 Good Things Around Us There are many things around us that help us stay healthy. Family & friends Beautiful scenery to look at Medicine & vitamins Oxygen in the air Nutrients in food
  43. 43. Environmental health vs Environmental science • Environmental health - it is the branch of public health which covers all the aspects of natural and built environment that affects the human health, • both environmental science and health are very much related because the environmental health deals with the natural environments that benefits the human health where as • science is focused on protecting the natural environment for the benefit of human health and ecosystem. 44
  44. 44. Environmental health vs Environmental protection • Environmental Health is focused on protecting public health by managing environmental conditions e.g. housing conditions, food & beverage safety, water & sewage, workplace safety, hazardous substances, etc. • Environmental Protection is focused on preserving the health of the environment and managing the natural resources . 45
  45. 45. Universal human rights: • “All people have the right to a standard of living adequate for health and well being of themselves and their family, including food, clothing, housing, health care, and the necessary social services” (Article 25, UN Dec 10,1948 universal declaration of human rights). 46
  46. 46. Equivalent in Ethiopian Constitution: • Article 44: (env right) All Persons have the right to live in a clean and healthy environment. • Article 90.1: the right to access to PH, education, clean water, housing, food, security • Article 92 (1-4):92.1: Government shall endeavor to ensure that all Ethiopians live in a clean and healthy environment. 47
  47. 47. Why Is Environmental Health Important? • Maintaining a healthy environment is central to increasing quality of life and years of healthy life. • Globally, 23% of all deaths and 26% of deaths among children under age 5 are due to preventable environmental factors. • Environmental factors are diverse and far reaching. • They include: • Exposure to hazardous substances in the air, water, soil, and food • Natural and technological disasters • Climate change • Occupational hazards • The built environment 48
  48. 48. Update of the global burden of disease attributable to the environment - Prüss- Ustün et al 2016 • 23% (95% CI: 13–34%) of global deaths and 22% (95% CI: 13–32%) of global disability adjusted life years (DALYs) were attributable to environmental risks in 2012. • The global disease burden attributable to the environment is now dominated by noncommunicable diseases. • Susceptible ages are children under five and adults between 50 and 75 years. • Nearly a quarter of global disease burden could be prevented by reducing environmental risks. • Eliminating hazards and reducing environmental risks will greatly benefit our health, will contribute to attaining the recently agreed Sustainable Development Goals and will systematically require intersectoral collaboration to be successful. 49
  49. 49. The Evolution of Environmental Health ENVIRONMENTAL HEALTH From Global to Local (Frumkin, Howard, 2005) • The history of and the development of Environmental Health are unique and complex in every country of the world. • It is not possible to assign a specific date from which problems relating to environment started. • However, human concern for environmental health dates from ancient times, and it has evolved and expanded over the centuries. 50
  50. 50. The Evolution of Environmental Health ENVIRONMENTAL HEALTH From Global to Local (Frumkin, Howard, 2005) 1. Ancient Origins • The notion that the environment could have an impact on comfort and wellbeing—the core idea of environmental health—must have been evident in the early days of human existence. • Our ancestors sought shelter in caves or under trees or in crude shelters they built. • Food safety - there must have been procedures for preserving food, and people must have fallen ill and died from eating spoiled food. • Dietary restrictions in ancient Jewish and Islamic law, such as bans on eating pork, presumably evolved from the recognition that certain foods could cause disease. 51
  51. 51. The Evolution of Environmental Health • Excreta Disposal- Around 2000 B.C., Israel provided guidelines as to how to manage wastes; instructions for the mgt of human waste are provided in the Bible (Deuteronomy 23:12–13). • Clean water- we can assume that early peoples learned not to defecate near or otherwise soil their water sources. • In the ruins of ancient civilizations from India to Rome, from Greece to Egypt to South America, archaeologists have found the remains of water pipes, toilets, and sewage lines, some dating back more than 4,000 years. • Polluted air - there is evidence in the release of high levels of smoke from ancient cave dwellers 52
  52. 52. • Mold in buildings- in the biblical book of Leviticus (14:33–45) may refer to an environmental health problem well recognized today • Rodents - European history was changed forever when infestations of rats in fourteenth century cities led to the Black Death. • The Black Death (Plague) was one of the most devastating pandemics in human history, resulting in the deaths of an estimated 75 to 200 million people in Eurasia and peaking in Europe from 1346 to 1353. • Plague is caused by the bacteria Yersinia pestis, a Gram-negative, rod-shaped coccobacillus. 53
  53. 53. 2. Industrial Awakenings • Modern environmental health further took form during the age of industrialization. • With the rapid growth of cities in the seventeenth and eighteenth centuries, the urban environment fostered  the spread of diseases with crowded, dark, unventilated housing; unpaved streets mired in horse manure and littered with refuse; inadequate or non existing water supplies; privy vaults unemptied from one year to the next; stagnant pools of water; ill-functioning open sewers; noises from clacking horse hooves, wooden wagon wheels, street railways, and unmuffled industrial machinery. 54
  54. 54. The Evolution of Environmental Health • The provision of clean water became an ever more pressing need, as greater concentrations of people increased both the probability of water contamination and the impact of disease outbreaks. • Regular outbreaks of cholera and yellow fever in the eighteenth and nineteenth centuries occurred. • Similarly, sewage management became a pressing need. • The industrial workplace — a place of danger and even horror—gave additional impetus to early environmental health. • Technology advanced rapidly during the late eighteenth and nineteenth centuries, new and often dangerous machines were deployed in industry after industry, and mass production became common. 55
  55. 55. • A key development in the seventeenth through nineteenth centuries was the quantitative observation of population health—the beginnings of epidemiology. • With the tools of epidemiology, observers could systematically attribute certain diseases to certain environmental exposures. • John Graunt (1620–1674), an English merchant and haberdasher, analyzed London’s weekly death records—the bills of mortality—and published his findings in 1662 as Natural and Political Observations Upon the Bills of Mortality; • This was one of the first formal analyses of this data source and a pioneering example of demography. The Evolution of Environmental Health 56
  56. 56. • William Farr (1807–1883) made the link between vital statistics and environmental health. • Farr made observations about fertility and mortality patterns, identifying rural-urban differences, variations between acute and chronic illnesses, and seasonal trends, and implicating certain environmental conditions in illness and death. • Farr’s 1843 analysis of mortality in Liverpool led Parliament to pass the Liverpool Sanitary Act of 1846, which created a sanitary code for Liverpool and a public health infrastructure to enforce it. The Evolution of Environmental Health 57
  57. 57. • Edwin Chadwick (1800–1890) was a pioneer in combining social epidemiology with environmental health. • Social epidemiology is a branch of epidemiology that focuses particularly on the effects of social-structural factors on states of health. • Five years later, following epidemics of typhoid fever and influenza, he was asked by the British government to investigate sanitation. • His classic report, Sanitary Conditions of the Labouring Population (1842), drew a clear link between living conditions—in particular overcrowded, filthy homes, open cesspools and privies, impure water, and miasmas—and health, and made a strong case for public health reform. The Evolution of Environmental Health 58
  58. 58. The Evolution of Environmental Health • The physician John Snow (1813–1858) was, like William Farr, a founding member of the London Epidemiological Society- father environmental epidemiology study. • During an 1854 outbreak of cholera in London, he observed a far higher incidence of disease among people who lived near or drank from the Broad Street pump than among people with other sources of water. • He persuaded local authorities to remove the pump handle, and the epidemic in that part of the city soon abated. 59
  59. 59. The Evolution of Environmental Health 3. The Modern Era • The modern field of environmental health dates from the mid- twentieth century. • Rachel Carson published a book in 1962 entitled Silent Spring about the effects of pesticides on large predatory birds, particularly the bald eagle. The 1962 publication of Rachel Carson’s Silent Spring was the best landmark. • Silent Spring focused on DDT, an organochlorine pesticide that had seen increasingly wide use since the Second World War. 60
  60. 60. The Evolution of Environmental Health • Carson had become alarmed at the ecosystem effects of DDT; • She described how it entered the food chain and accumulated in the fatty tissues of animals, how it indiscriminately killed both target species and other creatures, and how its effects persisted for long periods after it was applied. • She also made the link to human health, describing how DDT might increase the risk of cancer and birth defects. 61
  61. 61. The Evolution of Environmental Health • One of Carson’s lasting contributions was to place human health in the context of larger environmental processes. “Man’s attitude toward nature,” she declared in 1964, “is today critically important simply because we have now acquired a fateful power to alter and destroy nature. But man is a part of nature, and his war against nature is inevitably a war against himself. . . . [We are] challenged as mankind has never been challenged before to prove our maturity and our mastery, not of nature, but of ourselves”. • The recognition of chemical hazards was perhaps the most direct legacy of Silent Spring. 62
  62. 62. The Evolution of Environmental Health • Irving Selikoff (1915–1992) and his colleagues intensively studied insulators and other occupational groups and showed that asbestos could cause a fibrosing lung disease, lung cancer, mesothelioma, and other neoplasms. • Outbreaks of cancer in industrial workplaces- lung cancer in a chemical plant were underlined as the risk of carcinogenic chemicals. • Following these, cancer research was expanded, the American Cancer Society was made, and as a result environmental and occupational carcinogens became a focus of public, scientific, and regulatory attention. 63
  63. 63. The Evolution of Environmental Health • Herbert Needleman (December 13, 1927 – July 18, 2017 ), studying children in Boston, Philadelphia, and Pittsburgh, showed that lead was toxic to the developing nervous system, causing cognitive and behavioural deficits at levels far lower than had been appreciated. • Resulted in the removal of lead from gasoline, and as a result population blood lead levels plummeted. • Research also suggested that chemical exposures could threaten reproductive function, can result in decrease in sperm counts, and certain persistent, bioaccumulative chemicals (persistent organic pollutants, or POPs) could affect reproduction, perhaps by interfering with hormonal function. • Emerging evidence showed that chemicals could damage the kidneys, liver, and cardiovascular system and immune function and organ development. 64
  64. 64. The Evolution of Environmental Health • Bhopal disaster- isocyanate release killed hundreds and sickened thousands in Bhopal, India, in 1984, made it clear that industrialization posed real threats of chemical toxicity. • The use of herbicides in Vietnam war - Agent Orange was a powerful herbicide used by U.S. military forces during the Vietnam War to eliminate forest cover and crops for North Vietnamese and Viet Cong troops. • Chernobyl nuclear reactor accident - On April 26, 1986, Ukraine, in the former Soviet Union. The accident and the fire that followed released massive amounts of radioactive material into the environment. Resulted in displacement, death and chronic diseases. 65
  65. 65. The Evolution of Environmental Health • Even as the awareness of chemical hazards grew, supported by advances in toxicology and epidemiology, environmental health during the second half of the twentieth century was developing in a different direction altogether: environmental psychology. • Further development in modern environmental health was the continued integration of ecology with human health; the understanding of ecosystem function advanced greatly. • the role of humans in the context of ecosystems was better and better delineated. 66
  66. 66. The Evolution of Environmental Health • Clinical services related to environmental exposures expanded. • Occupational medicine and nursing had been specialties in their respective professions since the early twentieth century, incorporated a public health paradigm, drawing on toxicological and epidemiological data, using industrial hygiene and other primary prevention approaches, and engaging in worker education. 67
  67. 67. The Evolution of Environmental Health • Environmental health policy also emerged rapidly. With the promulgation of environmental laws beginning in the 1960s, legislators at the federal and state levels created agencies and assigned them new regulatory responsibilities. • These agencies issued rules that aimed to reduce emissions • At the dawn of the twenty-first century, then, the environmental health field had moved well beyond its traditional sanitarian functions. • Awareness of chemical toxicity had advanced rapidly, fuelled by discoveries in toxicology and epidemiology. 68
  68. 68. The Evolution of Environmental Health 4. Emerging Issues • Environmental health is a dynamic, evolving field. • As the twenty-first century unfolds, traditional sanitarian functions remain critically important, and chemical hazards will continue to be a focus of scientific and regulatory attention. • Looking ahead, we can identify at least five trends that will further shape environmental health: environmental justice, a focus on susceptible groups, scientific advances, global change, and moves toward sustainability. 69
  69. 69. UN CONFERENCES & PROTOCOLS ON ENVIRONMENT, SUSTAINABLE DEVELOPMENT , CLIMATE CHANGE • UN Conference on Human Environment, Stockholm (1972)- (Effect of Environmental degradation on Quality of Human Life) • Vienna Convention (1985)-(Protection of Ozone Layer) • Montreal Protocol (1989)-(Total Elimination of Ozone Depleting Substances) • Basal Convention (1989)-(Control of Trans-boundary Movements of Hazardous waste) • Geneva Convention (1990)-(Technology and financial help to Developing Countries) • UN Convention on Climate Change, New York (1992)-Economic Development and Environmental Protection • Bio-diversity Convention, Nairobi (1992)-(Preservation of Earth’s Bio-diversity) 70
  70. 70. UN CONFERENCES & PROTOCOLS ON ENVIRONMENT, SUSTAINABLE DEVELOPMENT , CLIMATE CHANGE • UN Conference on Environment and Development (Earth Summit) Rio de Janeiro, Brazil (1992)-(Environment and Sustainable Development) • Kyoto Protocol (1997)-(Stabilization of Green House Gases) • World Summit on Sustainable Development, Johannesburg (2002)-(International Solidarity on Environmental Issues) • Copenhagen Summit (2009)-(Road map for Post-Kyoto treaties) • Bali, Indonesia (2007)-Ad Hoc Working Group on Long-term Cooperative Action under the Convention(AWG-LCA) established • United Nations Climate Change Conference, Doha, Qatar (2012)-(The Doha Climate Gateway) • Paris Agreement (2016)-(Targets for everyone) 71
  71. 71. Hygiene and environmental health development in Ethiopia • Historical information about hygiene practice among the Ethiopian population is sparse. 1. A formal health service was organized in the Ministry of the Interior in 1908. Hygiene and sanitation in public health was a single service. 2. The Ministry of the Interior had a Proclamation and Legal Notices to exercise sanitation (urine handling, refuse and excreta management, street sweeping) in 1942–1943. 72
  72. 72. Hygiene and environmental health development in Ethiopia 3. The Ministry of Public Health was created in 1947. It organized Municipal and Provincial Public Health services to run both curative and public health. Hygiene and sanitation were the focus of these organizations. 4. Late in the 1970s, safe water supply and sanitation became components of primary healthcare. 73
  73. 73. Hygiene and environmental health development in Ethiopia 5. In the 1990s, the new Constitution in 1995 and a new Health Policy in 1993 were designed to reflect the social and health needs of the Ethiopian population. • Hygiene, sanitation and environmental matters are stated aims. 6. In early 2000 the Health Extension Program was designed and integrated into the Health Sector Development Program as a tool to enhance hygiene and sanitation in rural and urban areas. 74
  74. 74. Historical review of Environmental health training in Ethiopia • Organized sanitary inspectors training in Ethiopia can be traced to around 1942 when the New Ethiopian government was re-established after the 1941 victory of the Italian invasion. • After the liberation, a medical directorate was established in 1942 under the Ministry of Interior for carrying out medical and health services in the country. • Available records indicate that there was no Ethiopia personnel trained in the field of environmental sanitation during that time, hence, the directorate appointed a Sudanese health inspector to handle matters pertaining to environmental sanitation. 75
  75. 75. Historical review of Environmental health training … • In order to overcome lack of environmental health professionals, the United Nations Relief and Rehabilitation Administration (UNRRA) which was then assisting the country during the first phase of reconstruction initiated the first organized training of sanitary personnel in 1946. • Under this program the first class of 15 students completed their course in December 1946. Unfortunately, the sanitary inspector‘s training was discontinued during 1947-1949 due to withdrawal of external assistance for the program. • Some Ethiopians continued the training abroad getting fellowships from WHO. 76
  76. 76. Historical review of Environmental health training … • Therefore, three young men were sent to the school of Hygiene, Mbale, Uganda in 1950. • Another three were also sent to the American University of Beirut, Lebanon in 1952. • The training of sanitarians in a diploma program resumed in 1956 in Ethiopia. The duration of the course was one-year theory and practice in the college and one-year internship period with the other team members in rural Training Health Centre. 77
  77. 77. Historical review of Environmental health training … • Until 1964, the candidates were recruited after completion of eighth grade. • After 1964, the entrance requirement was raised to the completion of 10th grade and the training was extended to three years. • Average enrolment was around 30 students per year. The entrance requirement was further trained to a completion of 12th grade since 1978. 78
  78. 78. Historical review of Environmental health training … • From 1956 up to 1987/88, Gondar was the only School for the training of Sanitarians in the country. However, in 1988, another environmental health school was opened at diploma level in Jimma. Based on the current and anticipated environmental related health problems in the country, the professional training in the field was further upgraded to a degree level since 1984. 79
  79. 79. Hazard, exposure and risk • How an environmental factor can affect human health could be described in terms of hazard, exposure and risk. • A hazard is defined as a factor that may adversely affect health; it is basically a source of danger. • A hazard is a qualitative term expressing the potential of an environmental agent to harm the health of certain individuals if the exposure level is high enough and/or other conditions apply. • Exposure describes both the amount of, and the frequency with which, a substance reaches a person, group of people or the environment. 80
  80. 80. Integrated Environmental Health Middle School Project • University of Washington © 2005 81 Hazards A hazard is anything in the environment that can hurt you or make you sick. Bacteria & viruses Harmful chemicals Loud noises Tobacco smoke Stress
  81. 81. Hazard, exposure and risk • Human exposure can occur through several routes, most importantly, inhalation, ingestion and skin contact. • A risk is defined as the probability that a harmful event will occur, e.g., that an individual will become ill or die within a stated period of time; the probability of an unfavourable outcome. • It is the quantitative probability that a health effect will occur after an individual has been exposed to a specified amount of a hazard. • A hazard results a risk if there has been exposure. 82
  82. 82. Environmental Hazards • Environmental hazards may be biological, chemical, physical, psychological, sociological, or site and location hazards. 83
  83. 83. I: Biological Hazards • These are living organisms or their products that are harmful to humans A. Water-borne diseases are diseases that are transmitted through drinking water • Examples are polio virus, hepatitis A virus, Salmonella, Shigella, cholera, amoebic dysentery, Giardia, and Cryptosporidium. • These disease organisms are shed into the water in feces, and can produce illness in those who consume untreated, contaminated water • Our municipal water treatment facilities are usually able to purify water by removing these agents or killing them by disinfecting the water. 84
  84. 84. I: Biological Hazards… B. Food borne Diseases • are diseases transmitted in or on food 1. Examples of food-borne agents are the bacteria Salmonella, serotype enteritidis, Escherichia coli 0157:H7, as well as other agents. 2. To protect against food-borne diseases, sanitarians from local health departments routinely inspect food service establishments (restaurants) and retail food outlets (supermarkets) to verify that food is being stored and handled properly. 85
  85. 85. I: Biological Hazards… C. Vector-borne diseases • Vector borne diseases are those transmitted by insects or other arthropods • Examples are St. Louis encephalitis and La Crosse encephalitis transmitted by mosquitoes, and plague and murine typhus transmitted by fleas. • Improper environmental management can cause vector-borne disease outbreaks. 86
  86. 86. Humans Fetus and babies Other humans Water Air Insects Wild animals Livestock Pets Food Ways infectious disease organisms can enter the human body 87
  87. 87. II: Chemical Hazards • A toxic chemical is one that can cause temporary or permanent harm or death to humans and animals. • In 2004, the EPA listed arsenic, lead, mercury, vinyl chloride (used to make PVC plastics), and polychlorinated biphenyls (PCBs) as the top five toxic substances in terms of human and environmental health. • There are three major types of potentially toxic agents. • Carcinogens are chemicals, types of radiation, or certain viruses that can cause or promote cancer. • Mutagens are chemicals or forms of radiation that cause mutations, or changes, in the DNA molecules found in cells, or that increase the frequency of such changes. • Teratogens are chemicals that cause harm or birth defects to a fetus or embryo. 88
  88. 88. II: Chemical Hazards • Result from mismanagement or misuse of chemicals resulting in an unacceptable risk to human health. Pesticides • that have been manufactured for the purpose of reducing populations of undesirable organisms (pests) • Examples of categories of pesticides are herbicides and insecticides. • Most pesticides kill non-target organisms as well as the target, or pest species. • The wise use of pesticides can protect human health and agricultural crops. 89
  89. 89. Environmental tobacco smoke (ETS) • is an environmental hazard produced by millions that smoke • Diseases associated with ETS include lung cancer and perhaps heart disease. • ETS contains 4, 000 substances. • The US EPA has classified ETS as a Class A carcinogen. • Smoking has been increasingly restricted from public buildings and from many private work sites, • Ethiopia has also banned smoking cigarettes in public places, but not known about its practicability. • Regulation of smoking seems to be the best approach to controlling this pollutant II: Chemical Hazards--- 90
  90. 90. Lead • is a naturally occurring element that is used in the manufacturing of many industrial and domestic products • Health problems associated with the over exposure to lead are anemia, birth defects, bone damage, neurological damage, kidney damage, and others. • Exposure is by ingestion and inhalation. • Children are particularly at risk from eating peeling lead paint. • The prevalence of very high blood lead levels among young children declined significantly between 1984 and 1994 primarily because the removal of lead from gasoline. • Occupational exposure is a major source of lead intake for adults. II: Chemical Hazards--- 91
  91. 91. III. Physical hazards • A physical hazard is an agent, factor or circumstance that can cause harm with or without contact. • They can be classified as type of occupational hazard or environmental hazard. • Physical hazards include ergonomic hazards, radiation, heat and cold stress, vibration hazards, and noise hazards 92
  92. 92. IV. Psychological hazards • A psychological hazard is any hazard that affects the mental well- being or mental health of the worker by overwhelming individual coping mechanisms and impacting the worker's ability to work in a healthy and safe manner. • are environmental factors that produce psychological changes expressed as stress, depression, hysteria. 93
  93. 93. V. Sociological hazards • Are those that result from living in a society where one experiences noise, lack of privacy and overcrowding. • Population growth may be a sociological hazard • When environmental resources can support no further growth, the population has reached the equilibrium phase and the environment is said to be at its carrying capacity 94
  94. 94. VI. Site and Location Hazards • Natural disasters are geographical and meteorological events of such magnitude and proximity to communities that they produce significant damage and injuries. • Examples are cyclones, earthquakes, floods, hurricanes, tornadoes, typhoons, and volcanic eruptions. • Biological, psychological and sociological hazards may increase following a natural disaster. 95
  95. 95. Methods for monitoring and control of environmental hazards 96
  96. 96. Introduction • The monitoring and control of environmental hazards to health entails a wide range of actions, each tailored to the particular hazard or form of public health concern. • Monitoring implies use of routine measurements to detect changes in the environment or health, and can be based on data from a wide variety of sources. • The control of environmental hazards depends on defining acceptable levels of exposure and hence health risk and determining the levels of control needed to keep exposure below specified thresholds. 97
  97. 97. Bio-marker Substances (molecules) used as indicators of a biologic state – i.e. as an indicator of normal or pathogenic processes or of biological response to an external agent. Examples include: an antibody to indicate infection, a DNA adduct to indicate modification of genetic material or a protein that correlates with the risk or progression of disease. Bio-monitoring (human) Monitoring in human beings, using biomarkers, that focus on environmental exposures, diseases and/or disorders and genetic susceptibility, activities and their potential relationships. Disease cluster An unusual aggregation of health events that are grouped in space and time. HACCP Hazard Analysis and Critical Control Points – a systematic preventive approach to food and pharmaceutical safety that addresses physical, chemical, and biological hazards as a means of prevention rather than finished product inspection. Key definitions and terms 98
  98. 98. Monitoring The performance and analysis of routine measurements aimed at detecting changes in the environment or health status of populations. May also imply intervention as indicated by monitoring data. Surveillance Ongoing scrutiny, generally using methods distinguished by their practicability, uniformity, and frequently their rapidity, rather than by complete accuracy. Its main purpose is to detect changes in trend or distribution in order to initiate investigative or control measures. Key definitions and terms 99
  99. 99. Principles Approaches to monitoring and control • For any potential environmental hazard one of the main principles for monitoring and control is to identify the critical agents, pathways and populations at risk. • Such considerations will guide the methods to be used for monitoring and surveillance. 100
  100. 100. Monitoring data Monitoring can use data from a range of sources, including: • Emissions inventories (records of the permitted or actual level of emissions from specified sources); • Environmental data (measurements of the concentrations of pollutants in the environment); • Bio-monitoring data (measurements of specific agents or their metabolic products in biological samples); • Health data ⁻ Routine (surveillance) data; ⁻ Clinical surveillance (relevant to specific exposed populations); 101
  101. 101. Monitoring data… Relevant health data might include: oinfectious disease monitoring data; ohealth care utilization data (hospital admissions, primary care consultations); obirths, congenital anomalies and related data; ocancer registrations; omortality statistics; oepidemiological surveys. 102
  102. 102. Monitoring data… • Epidemiological surveys are usually undertaken for research purposes rather than as part of monitoring, but periodic surveys may provide useful evidence about biological uptake and effects (bio-markers from clinical specimens, indicator diseases states). 103
  103. 103. Monitoring data… • In general, the control of environmental hazards depends on: 1. defining acceptable levels of exposure and hence health risk 2. determining the levels of control needed to keep exposure below the specified thresholds. • Such assessment usually takes account of toxicological and epidemiological evidence, and evidence on exposure pathways, environmental persistence, bio-accumulation etc. 104
  104. 104. Control measures A range of methods of control may be applied, including: • Licensing / banning specific substances (e.g. CFCs); • Setting of emissions controls (e.g. vehicles exhausts, industrial emissions); • Enforcement of concentrations or exposure limits for specific target groups (e.g. radiation workers); • Enforcement of health and safety protection (e.g. for workers handling biological agents). • Setting of guidelines/standards relating to environmental levels (e.g. air pollution monitoring) 105
  105. 105. Control of specific environmental hazards-Water and food • Quality standards are set for the physical, chemical and biological characteristics of drinking water and monitored throughout the water treatment and distribution network through to the household tap. 106
  106. 106. Control of specific environmental hazards-Water and food • Biological and chemical testing is also carried out in the food industry, with water safety, • the approach is typically based on the principles of the Hazard Analysis and Critical Control Points (HACCP), which seeks to identify potential hazard points, so that key actions, known as Critical Control Points (CCP's) can be taken to reduce or eliminate the risk of the hazards being realized. • The system is used at all stages of food production and preparation processes including packaging, distribution, etc. 107
  107. 107. Control of specific environmental hazards-Air pollution • periodically to review and assess the current, and likely future, air quality against national air quality objectives. 108
  108. 108. Control of specific environmental hazards-Noise • Noise is a complex exposure, as its effects on health and well-being are function of multiple parameters, including: • its intensity, its duration, its intermittency, its nature and quality, and its origin. 109
  109. 109. Ionizing and electro-magnetic radiation • Monitoring and protection against radiation risks covers a number of important areas: • Radon monitoring of households in high radon areas • Workers in the nuclear industry, or in other fields where there is exposure to ionizing radiation (e.g. medical imaging), are required to wear radiation badges to monitor personal exposure. 110
  110. 110. Principles of hazard management • Establish the context and identify the hazard: These are the first steps. • You should identify the type of the hazard in as much detail as you can. • You should also describe the exposure conditions and try to answer the following questions: • What is the source of the hazard? • Who is exposed? • What are the pathways or activities that expose a person? • What part of the environment is involved in the transfer of the hazard to humans? 111
  111. 111. Principles of hazard management… • Hazard/risk analysis and evaluation: analyse the risk and evaluate the potential of the hazard to cause damage to health. The evaluation may require appropriate design, sampling and laboratory investigation. • Communicate and consult: When the hazards and risks have been determined, advice can be communicated on the interventions or control measures that are needed to control the hazard. There can also be consultations with relevant people and organizations. 112
  112. 112. Principles of hazard management… • Treat the hazard/risk: The interventions or control measures are carried out by the person or people responsible for the hazard or risk. • Monitoring and reviewing: The implementation of interventions or control measures for the hazard must be followed up in order to determine whether they are successful. Correction measures can be applied if there is any failure. Identifying appropriate indicators for monitoring is critical and must be done formally. 113
  113. 113. Principles of hazard management… • Record keeping: Keeping records and reports on hazard management is always important. These records must contain the type of hazard, exposures and what control measures were taken. 114
  114. 114. Figure. The hazard management process. 115