Risk assessment and regulation of carcinogens in the workplace.
Schulte-PA; Ahlers-H; Dankovic-D
Clin Occup Environ Med 2002 Nov; 2:727-735
Risk assessment is defined as "the characterization of the potential adverse health effects of human exposures to environmental hazards." Risk assessments are conducted to provide estimates of the likelihood of illness and injury as a consequence of exposure to various hazards, including carcinogens. They are needed when social policies are in dispute, when the health consequences of alternative policies are not subject to direct measurement (at least in a timely fashion), and when the scientific analysis of a hazard is not complete. Risk assessments often are conducted as a part of regulatory decision making. Risk assessment has a range of meanings. At the basic level, it is used to evaluate the potential of a hazard to cause disease. It can be a qualitative or quantitative exercise. Quantitative risk assessment (QRA) describes the probability of response to a given level of exposure. The assessment procedure involves the development of an exposure-response curve for the target species (e.g., humans) based on animal and human information. These curves are used to estimate the levels of exposure that may be considered safe. QRA is a process of extrapolating from the range of direct observation to a lower and potentially safer range, for which there are few or no data. The foundation for risk assessment and regulation in the workplace was influenced by three fundamental events: the Occupational Safety and Health (OSH) Act in 1970; the Supreme Court decisions on benzene and cotton dust in 1980 and 1981, respectively; and the publishing of the book "Risk Assessment in the Federal Government: Managing the Process." These three events occurred in an era between 1958, when the Delaney Clause in the food and drug laws (prohibiting the inclusion of known carcinogens in food) was enacted, and 1986, when the Environmental Protection Agency (EPA) issued guidelines for carcinogen risk assessment . This period was a time of much public concern and debate about cancer and chemicals. It was characterized by a perception of rising national rates of some cancers, the startling reports of lung and mesothelioma cancer in asbestos workers, angiosarcoma in workers exposed to vinyl chloride, bladder cancer in dye and other workers, and the advancement of the one-hit model of carcinogenesis. This model referred to the probability that a single molecule of some classes of carcinogens could interact with DNA from a single cell and begin an irreversible carcinogenic process. At the same time, advancements in analytical chemistry allowed for the detection of trace amounts of chemicals in tissues, often in the range of parts per billion. These developments fueled concern about the potential cancer risks associated with low-level exposures to chemicals and a desire to quantitatively estimate those risks.
Risk-analysis; Risk-factors; Carcinogens; Workplace-studies; Occupational-exposure; Humans; Environmental-hazards; Exposure-levels; Cancer; Exposure-limits; Qualitative-analysis; Quantitative-analysis; Regulations; Chemical-processing; Analytical-chemistry
National Institute for Occupational Safety and Health, EID, Mail Stop C-14, 4676 Columbia Parkway, Cincinnati, OH 45226
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Clinics in Occupational and Environmental Medicine