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3.3: Environmental Risk Management

  • Page ID
    12023
  • General Definitions

    For most people, the concept of risk is intuitive and, often, experiential; for instance most people are aware of the considerably greater likelihood of suffering an injury in an automobile accident (116/100 million vehicle miles) versus suffering an injury in a commercial airplane accident (0.304/100 million airplane miles). Environmental risk can be defined as the chance of harmful effects to human health or to ecological systems resulting from exposure to any physical, chemical, or biological entity in the environment that can induce an adverse response (see Module 9.5 for more detail on the science of risk assessment). Environmental risk assessment is a quantitative way of arriving at a statistical probability of an adverse action occurring. It has four main steps:

    1. Identification of the nature and end point of the risk (e.g. death or disability from hazardous chemicals, loss of ecological diversity from habitat encroachment, impairment of ecosystem services, etc.)
    2. Development of quantitative methods of analysis (perturbation-effect, dose-response)
    3. Determination of the extent of exposure (i.e. fate, transport, and transformation of contaminants to an exposed population), and
    4. Calculation of the risk, usually expressed as a statistical likelihood.

    Risk management is distinct from risk assessment, and involves the integration of risk assessment with other considerations, such as economic, social, or legal concerns, to reach decisions regarding the need for and practicability of implementing various risk reduction activities. Finally, risk communication consists of the formal and informal processes of communication among various parties who are potentially at risk from or are otherwise interested in the threatening agent/action. It matters a great deal how a given risk is communicated and perceived: do we have a measure of control, or are we subject to powerful unengaged or arbitrary forces?

    The Beginnings of Modern Risk Management

    The beginnings of environmental risk management can be traced to the fields of public health, industrial hygiene, and sanitary engineering, which came into prominence in the latter decades of the 19th century and beginning of the 20th. The spread of disease was a particularly troublesome problem as the country continued to urbanize. For instance if you lived your life in, say, Chicago during the period 1850-1900 (a typical lifespan of the day), you had about a 1 in 100 chance of dying of cholera (and a 1 in 2000 chance of dying of typhoid), of which there were periodic epidemics spread by contaminated drinking water. Chicago's solution was to cease polluting its drinking water source (Lake Michigan) by reversing the flow of its watercourses so that they drained into the adjacent basin (the Mississippi). The widespread chlorination of municipal water after 1908 essentially eliminated waterborne outbreaks of disease in all major cities (with some notable exceptions—the outbreak of chlorine-resistant Cryptosporidium parvum in Milwaukee's drinking water in 1993 resulted in the infection of 403,000 people with 104 deaths).

    Parallel work on the effects of chemical exposure on workers (and poor working conditions in general) were pioneered by Alice Hamilton (1869-1970), who published the first treatise on toxic chemical exposure "Industrial Poisons in the United States" in 1925. Hamilton is considered the founder of the field of occupational health. In 1897 she was appointed professor of pathology at the Women's Medical School of Northwestern University, and in 1902 she accepted the position of bacteriologist at the Memorial Institute for Infectious Diseases in Chicago. Dr. Hamilton joined Jane Addams's Hull House, in Chicago, where she interacted with progressive thinkers who often gravitated there, and to the needs of the poor for whom Hull House provided services.

    Environmental Contamination and Risk

    Events during the period 1920-1950 took an unfortunate turn. Global conflicts and economic uncertainty diverted attention from environmental issues, and much of what had been learned during the previous hundred years, for example about soil conservation and sustainable forestry, ceased to influence policy, with resultant mismanagement on a wide scale (see Figures \(\PageIndex{1}\) and \(\PageIndex{2}\)).

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    Figure \(\PageIndex{1}\) Texas Dust Storm. Photograph shows a dust storm approaching Stratford, TX in 1935. Source: NOAA via Wikimedia Commons

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    Figure \(\PageIndex{2}\) Clear Cutting, Lousiana 1930. Typical cut-over longleaf pine area, on Kisatchie National Forest. Areas of this type were the first to be planted on this forest. Circa 1930s. Source: Wait, J.M. for U.S. Forest Service. U.S. Forest Service photo courtesy of the Forest History Society, Durham, N.C.

     

     

    In the aftermath of the World War II, economic and industrial activity in the United States accelerated, and a consumer-starved populace sought and demanded large quantities of diverse goods and services. Major industrial sectors, primary metals, automotive, chemical, timber, and energy expanded considerably; however there were still few laws or regulations on waste management, and the ones that could and often were invoked (e.g. the Rivers and Harbors Act of 1899) were devised in earlier times for problems of a different nature. The Module 9.2 provides a more detailed accounting of the current framework for managing waste. Here we recount the circumstances that eventually resulted in the promulgation of environmental risk as a basis for public policy, with subsequent passage of major environmental legislation.

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    Figure \(\PageIndex{3}\) Zinc Smelter. Photograph shows a local smelter in a small valley town in Pennsylvania with, essentially, uncontrolled emissions. Source: The Wire Mill, Donora, PA, taken by Bruce Dresbach in 1910. Retrieved from the Library of Congress

     

    If there were any doubts among American society that the capacity of the natural environment to absorb human-caused contamination with acceptably low risk was indeed infinite, these were dispelled by a series of well-publicized incidents that occurred during the period 1948-1978. Figure \(\PageIndex{3}\) shows a local smelter in a small valley town in Pennsylvania with, essentially, uncontrolled emissions. During periods of atmospheric stability (an inversion), contaminants became trapped, accumulated, and caused respiratory distress so extraordinary that fifty deaths were recorded. Figure \(\PageIndex{4}\) illustrates the dramatically poor air quality, in the form of reduced visibility, during this episode. Such incidents were not uncommon, nor were they limited to small American towns. A well-documented similar episode occurred in London, England in 1952 with at least 4000 deaths, and 100,000 illnesses resulting.

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    Figure \(\PageIndex{4}\) Noon in Donora. Photograph, dated October 29, 1948, illustrates the extremely poor air quality in the Pennsylvania town at the time. Source: NOAA

     

    The generally poor state of air quality in the United States was initially tolerated as a necessary condition of an industrialized society. Although the risks of occupational exposure to chemicals was becoming more well known, the science of risk assessment as applied to the natural environment was in its infancy, and the notion that a polluted environment could actually cause harm was slow to be recognized, and even if true it was not clear what might be done about it. Nevertheless, people in the most contaminated areas could sense the effects of poor air quality: increased incidence of respiratory disease, watery eyes, odors, inability to enjoy being outside for more than a few minutes, and diminished visibility.

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    Figure \(\PageIndex{5}\) Cuyahoga River Fire, 1969. Photograph illustrates a 1969 fire on the Cuyahoga River, one of many fires during the time period. Source: NOAA.

     

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    Figure \(\PageIndex{6}\) Love Canal. The Love Canal region of Niagara Falls, NY, 1978 showing the local grade school and neighboring houses. Source: New York State Department of Health (1981, April). Love Canal: A special report to the Governor and Legislature, p. 5.

     

    Risk Management as a Basis for Environmental Policy

    Environmental scientists of the day were also alarmed by the extent and degree of damage that they were documenting. The publication of Silent Spring in 1962 by Rachel Carson (1907-1964), about the impact of the widespread and indiscriminate use of pesticides, was a watershed moment, bringing environmental concerns before a large portion of the American, and global, public. Carson, a marine biologist and conservationist who initially worked for the U.S. Bureau of Fisheries, became a full time nature writer in the 1950s. She collected scientifically documented evidence on the effects of pesticides, particularly DDT, heptachlor, and dieldrin, on humans and mammals, and the systemic disruption they caused to ecosystems. Silent Spring is credited with bringing about a ban on the use of DDT in the United States, and setting in motion a chain of events that would ultimately result in the transformation of environmental public policy from one based on the problems and attitudes that brought about nineteenth century conservation, to one based on the management of risks from chemical toxins. The U.S. Environmental Protection Agency was established in 1970, just eight years after the publication of Silent Spring. The same year Earth Day was created.

    As noted, the modules in the Chapter 9.1 contain a comprehensive treatment of the major laws and regulations that underpin the risk management approach to environmental policy. However it is worth considering one law in particular at this point, the National Environmental Policy Act of 1970 (NEPA), because it provides a legal basis for U.S. environmental policy, and lays out its terms clearly and unambiguously. NEPA established a national goal to create and maintain "conditions under which [humans] and nature can exist in productive harmony, and fulfill the social, economic and other requirements of present and future generations of Americans[emphasis added]" (NEPA, 1970). Further, NEPA saw the need for long term planning, to "fulfill the responsibilities of each generation as trustee of the environment for succeeding generations," for equity "to assure for all Americans safe, healthful, productive, and esthetically and culturally pleasing surroundings," and for economic prosperity as we "achieve a balance between population and resource use that will permit high standards of living and a wide sharing of life's amenities" (NEPA, 1970). Although the exact word "sustainable" does not appear, NEPA is in all major respects congruent with the goals of the Brundtland Report (written 17 years later, see Chapter 2), retains the character of American conservation, and anticipates the need to integrate environmental quality with social and economic needs.

    Every four to six years the U.S. EPA releases its Report on the Environment, a collection of data and analysis of trends on environmental quality. It is quite comprehensive; reporting on an array of measures that chart progress, or lack thereof, on human impacts on the environment and, in turn, the effects of our actions on human health. It is difficult to summarize all the information available in a concise way, however most measures of human exposure to toxic chemicals, dating in many cases back to the late 1980s, show clear downward trends, in some cases dramatically so (for example DDT in human tissues, lead in blood serum, exposure to hazardous wastes from improper disposal, exposure to toxic compounds emitted to the air). In addition, many of other indicators of environmental quality such as visibility, drinking water quality, and the biodiversity of streams, show improvement. These are success stories of the risk management approach to environmental quality. On the other hand, other measures, such as hypoxia in coastal waters, quantities of hazardous wastes generated, and greenhouse gases released are either not improving or are getting worse.

    References

    National Environmental Policy Act of 1970, 42 U.S.C., 4321, et seq. (1970). http://www.epa.gov/compliance/basics/nepa.html