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University of Toronto Scarborough
Environmental Science
Jovan Stefanovic

EESA10 Notes Chapter 1: Environment, Health and Risk -Improved water, food, and milk sanitation, reduced physical crowding, improved nutrition, and central heating with cleaner fuels were the developments most responsible for the great improvements in public health achieved during the twentieth century. The Environmental Crisis -For the first time, human beings are altering the basic operations of the earths atmosphere, geosphere, and biosphere -Between one-third and one-half of the land surface has been transformed by human action -Biologists have observed startling declines in frog populations around the world, even in isolated and relatively pristine environments. It appears that no single factor is responsible -The declining health of frogs, birds, and thousands of other organisms may be the clearest indication of environ- mental threats to human health -odays environmental degradation is rapidly creating an unprecedented global crisis. The driving forces are population growth and industrialization.9 -The rate of industrialization, which has far outpaced the growth in population, is a powerful determinant of environmental transformation. In the past 100 years, the worlds industrial production increased 100- fold. -In 150 years, human activity has increased the atmospheric concentration of carbon dioxide by nearly 30 percent, dou- bled the concentration of methane (both potent greenhouse gases), and introduced long-lived ozone-destroying chlorofluorocarbons into the stratosphere -From a medical standpoint, health is viewed as an attribute of the individ- ual. -in the past decade, biologists, ecologists, and physicians have also developed a concept of ecosystem health.2,14,15 This idea recognizes that humans are participants in complex ecosystems and that their poten- tial for health is proportional to the health function of those ecosystems. - An ecosystem health stance is a nonanthropocentric, holistic worldview in- creasingly shared by biological scientists.15 -In the anthropocentric view of the world, humans are the most important of all the species and should have dominion over nature. -Some of us dis- tance ourselves from the discussion because we find it frightening or over- whelming. As a result, policymakers and politicians are not pressed to confront the consequences of the continuing expansion of human enter- prise. Health and the Environment -The health effects of global change are often indirect and difficult to assess, and the quality of evidence for the health-related outcomes of global environmental change varies widely.3 For example, the prevalence of malaria has increased worldwide, but no clear relation to climate change has been established -the health science necessary to understand global environmental change is increasingly interdiscipli- nary and requires collaboration over long periods among meteorologists, chemists, biologists, agronomists, and health scientists. Organizing and funding such science is difficult -politicians and policymakers are loath to commit resources to predicted but unproven future outcomes. 1 www.notesolution.comEESA10 Notes -Environmental degradation exaggerates the imbalance between population and resources, increases the costs of development, and worsens the extent and severity of poverty. -interactions bc poverty, population growth, and environmental degradation impede sustainable economic development and worsen population health.19 -It is important for scientists to anticipate the potential consequences of environmental change.20 Serious environmental problems are often un- known or unrecognized. -Two recent developments have drawn renewed attention to the health risks of industrical chemicals known as persistent organic pollutants (POPs): the identification of medical waste as a significant source of toxic pollution and the emergence of the health effects field of endocrine dis- ruption -Medical-waste incineration is a major source of the dioxin and mercury released into the environment. Almost all humans have measur- able residues in their tissues of chlorinated hydrocarbon chemicals, in- cluding pesticides, polychlorinated biphenyls (PCBs), and dioxin. -Pressured by advocacy organizations, the health care industry has begun efforts to better manage medical materials and waste -En- docrine disrupters are a class of chemicals, including many of the persistent organic pollutants, that imitate or block the actions of hormones. These chemicals produce a variety of reproductive and neurodevelopmental dis- turbances -Endocrine disruption joins carcinogenesis as the environmental health outcome of concern Physicians and Public Health Professionals - physician needs to call on a number skills, including the abil- ity to evaluate and assess the nature and the extent of the patients expo- sure to an environmental hazard, the ability to assess the degree to which the hazard presents a health threat, and the ability to communicate the ex- tent of the risk to the patient or to the community so as to minimize or prevent further exposure.33 -med students receive little training in these -An important target of environmental education ought to be physi- cians. Most physician training is designed around the biomedical model of finding and fixing the health problem. We must change the orientation -This will require a shift from a bioengineering to an ecological model in medicine. Solutions -A first step is to stop further environmental degradation -A second step will be to change the relationship between developed and developing countries. Industrialized nations will need new strategies for transferring technologies, training, and education -deal with international debt and must promote economic development that minimizes the destruction of resources -A third initiative is to develop long-term educational strategies that will change the mindsets of individuals and institutions with respect to protecting the environment and promoting health -Shifting our way of thinking to the interdisciplinary, the intergenerational, and the in- ternational will demand incorporation of these concepts into the curricula of all disciplines at the undergraduate and graduate levels 2 www.notesolution.comEESA10 Notes Chapter 2: Urban and Transboundary Air Pollution -In 1700, the epi- demiologist and physician Ramazzini published the first textbook on occupational disease, De Morbis Artificium Diatriba, in which he described in detail respiratory diseases due to exposure to silica, cotton, tobacco, flour, and other materials -Recognition of the relationship between nonworkplace (i.e., com- munity) air pollution and respiratory disease dates back to the first use of coal as a combustion source in the fourteenth century -Later, in the in- dustrial nations of Europe and North America, whole communities were engulfed in air pollutants, -The worst episode occurred in London, where the number of deaths ulti- mately reached over 4,000, a total second only to that of the influenza pandemic of 19171 -as a result of this e epidemics, scientists and govs paid more attention to air pollution -Despite these efforts, we face a crisis of worldwide air pollu- tion today. This crisis has several aspects. - First, since the atmosphere is dy- namic and always changing, contaminants are transported, diluted, precipitated, and transformed -Second, the primary emissions of sulfur oxides, nitrogen oxides, car- bon monoxide, respirable particulates, and metals (e.g., lead and cad- mium) are severely polluting cities and towns -Many cities in developing nations and in Eastern Europe are experiencing uncontrolled industrial expansion -poorer countries (relying heavily on coal) had significantly higher levels of total suspended particulates (TSPs) than wealthier nations -Third, in nations that have reduced the primary emissions from heavy industry, power plants, and automobiles, new problems have arisen from pollution by newer industries and from air pollution caused by secondary formation of acids and ozone. -contribute to higher mortality rates from acute respiratory disease in children under 5 in developing countries -Finally, although this report is focused on the human health effects of air pollution, there are also many other aspects of the problem. For exam- ple, damage to ecosystems and agriculture from acid rain, damage to buildings and artwork, and reduced visibility are all attributable to air pol- lution Defining Adverse Health Effects -any effect that results in altered structure or impaired function or that represents the beginning of a se- quence of events leading to altered structure or function is considered an adverse health effect. Specific Air Pollutants Associated with Adverse Respiratory Effects -Table 2.1 Principal air pollutants, their sources, and their respiratory effects PAGE 18 Sulfur Dioxide and Acidic Aerosols -Sulfur dioxide (SO2) is produced by the combustion of sulfur contained in fossil fuels, such as coal and crude oil. Therefore, the major sources of en- vironmental pollution with sulfur dioxide are electric power generating plants, oil refineries, and smelters -profound implications for nations such as China, which possesses 12 percent of the worlds bituminous coal reserves and depends mainly on coal 3 www.notesolution.com
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