Environmental Danger of BaP Levels
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Benzo[a]pyrene, also known as 3,4benzopyrene, is one of a myriad of chemicals which occur in smoke. It is usually formed by incomplete combustion. Studies have shown that, under certain circumstances, benzo[a]pyrene (BaP) may induce tumors in laboratory animals. No evidence, however, has thus far been discovered which indicates that BaP causes cancer in humans. Regardless of this fact though, the United States Environmental Protection Agency (EPA) has established exceedingly stringent standards for occupational BaP exposures. These regulations are highly inappropriate. Furthermore, by diverting limited company resources away from more necessary concerns, the standards may actually serve to compromise work place safety. The substance, benzo[a]pyrene, is a polycyclic aromatic hydrocarbon (PAH) compound. Its chemical formula is as follows: C20H12. Pure BaP may exist as either pale yellow needles or plates. The melting point of this material is between 179 and 179.3 degrees Celsius (EPA, 1990, p. 29). In general, benzo[a]pyrene is formed by burning. It occurs ubiquitously throughout the environment and may be derived from both manmade and natural sources. For example, BaP has been detected in drinking water, soils, and food. Observed concentrations in untreated water may range from 0.6 nanograms/liter to as high as 210 nanograms/liter. Treated waters tend to have somewhat less BaP; their benzo[a]pyrene content can range down to as little a
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rious other carcinogenic substances. In fact, in its refined state, 3,4benzopyrene is not even a carcinogen (Dahl, 1989, pp. 143144). Studies have shown that only its metabolites are able to bind DNA (Strauss et al., 1978, p. 189). The compound, B[a]P7,8diol9,10epoxide (and not BaP), is primarily responsible for the association with tumorigenicity. Furthermore, this epoxide's effects may be magnified by various other components of the chemical mixtures. Such interactions could have caused some of the observed carcinogenic activity previously attributed to BaP (EPA, 1990, p. 67). Already, researchers have shown that many derivatives of benzo[a]pyrene lack both mutagenicity and carcinogenicity (AshwoodSmith et al., 1978, p. 123).
Despite these revelations though, the EPA continues to classify benzo[a]pyrene as a member of the "Group 2B" family of chemicals. These compounds are described as "probable human carcinogens." Although they may sometimes be carcinogenic in animals, they lack any proven carcinogenicity in humans
(EPA, 1990, p. 89). The problem with this classification scheme, however, relates to the government's approach to "carcinogens." According to the U.S. Secretary of Labor, there are no safe occupati
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Approximate Word count = 1826
Approximate Pages = 7 (250 words per page)
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