Document bBz9794Ka482a27VGbGNk3k3y

22646 Federal Register / Vol. 51. No. 119 / Friday, June 20, 1986 / Rules and Regulations as low as 37 f-y/cc (this level produced exposure to hazardous workplace OSHA has followed these guidelines a 1% prevalence of crepitations) and is chemicals takes into consideration a in making a determination that the risk consistent with the predictions made number of factors that are consistent nf material health impairment resulting above, During the hearings, several with recent court interpretations of the from occupational exposure to asbestos witnesses stressed the range of physical OSH Act and rational, objective policy is significant. The epidemiological and and mental disability/impairmenl which formulation. As prescribed by Section toxicological evidence and testimony may occur long before even radiologic evidence of disease appears. Typical of these comments were those made by Dr. Irving Selikoff of the Mount Sinai School of Medicine. He stated: 6(b)(5) of the Act, OSHA examines the body of "best available evidence" on the toxic effects of hazardous chemicals to determine the nature and extent of possible health consequences resulting presented in the November notice and in Section IV (Health Effects) of this preamble clearly show that exposure to asbestos is carcinogenic to humans and additionally causes disabling fibrotic . So. what you're seeing on x-ray is always "very much less than is really present from exposure to,the hazardous agent in question. Quantitative risk assessments pathologically. So that, when you see a are conducted, where possible, and the positive x-ray. there's a fair amount there in the lung . . . I've seen people with comparatively little on x-ray. who can't walk across a room. But by and large, all it means is that there's been scarring |TR. 7/2. p. 170). While several participants commented in general on the risk of asbestosis, there was little direct comment on OSHA's quantitative estimates of risk. Hence, for these revised rules. OSHA has relied on the models developed for the proposal to predict the risk of asbestosis at the new PEL of 0.2 f/cc. Using OSHA's best estimate of risk, that from the Fihkelstein data, OSHA predicted that exposure over a working lifetime to the 2 f/cc level will result in approximately a 5% incidence of asbestosis. Reducing the exposure to 0.2 f/cc would result in a lifetime incidence of asbestosis of 0.5%. While OSHA did not make predictions of risk at levels below 0.5 f/cc in the proposed rules, testimony received during the rulemaking increases OSHA's confidence that the Agency's estimates of risk at 0.2 f/cc are valid and reasonable. This is due primarily to the comments noting the validity of the model in the low dose region. Given the results are considered along with other relevant information, such as the nature and severity of the health consequences, to determine whether a hazardous agent poses a significant risk to workers at the current permissible exposure level. The Agency also determines whether a reduction in the permissible exposure "level for the hazardous agent will substantially reduce that risk. The Court gave some general guidance to the Agency for arriving at findings of the significance of an occupational health risk. It recognized that the Agency's determination that a particular level of risk is "significant" will be based largely on policy considerations (IUD v. API, 448 U.S. 655. 656. n. 62). To illustrate how one may make a determination from quantitative information that a health risk is significant, the Court stated as follows: It is the Agency's responsibility to determine in the first instance what it considers to be a "significant" risk. Some risks areplainly acceptable and others are plainly unacceptable. If. for example, the odds are one in a billion that a person will die from cancer by taking a drink of chlorinated water, the risk clearly could not difficulties in accurately diagnosing be considered significant. On the other hand, cases of asbestosis and the fact that if the odds are one in a thousand that regular OSHA's estimates only take the risk of disabling asbestosis into account. OSHA believes that the Agency's estimates may be underestimates of the true risk of asbestosis to exposed workers. VI. Significance of Risk inhalation of gasoline vapors that are 2% benzene will be fatal, a reasonable person might well consider the risk significant and take appropriate steps to decrease or eliminate it [IUD v. API 448 U.S. at 855). Although the Court's example is based on a quantitative expression of the risk, the Court indicated that the significant As discussed above in Section III risk determination required of OSHA is (Pertinent Legal Authority), the Supreme not "a.mathematical straitjacket," and Court in the Beiizene case [Industrial that "OSHA is not required to support Union Deportment, AFL-CIO v. the finding that a significant risk exists American Petroleum Institute 448 U.S. . with anything approaching scientific lung disease. Lung cancer constitutes the greatest health risk to asbestos workers: in some occupational cohorts, this disease has been responsible for more than half of the excess mortality from asbestos exposure. Malignant mesotheliomas of the pleura and peritoneum, which are extremely rare among non-exposed persons, have been conclusively linked with asbestos exposure. Some studies of asbestosexposed workers have also shown increases in mortality from gastrointestinal and other types of cancer. It has been known for years that exposure to asbestos is the only known cause of asbestosis, a progressive, fibrotic lung disease causing effects ranging from shortness of breath during exertion to complete disability, respiratory and cardiac failure, and death. OSHA's determination that the health risks from asbestos exposure is significant is based, in part, on the irreversible and ultimately fatal nature of these diseases, particularly of lung cancer and mesothelioma. The finding that a significant risk exists is primarily supported by OSHA's quantitative risk assessment, which is based on studies of asbestos-exposed worker populations. OSHA's risk assessment (discussed in Section V of this preamble) estimates that 64 excess cancer deaths (including those from lung and gastrointestinal cancer and mesothelioma) will occur among 1,000 workers exposed at the existing permissible exposure limit of 2 f/cc for 45 years, a working lifetime. The estimates of mortality risk from mesothelioma, lung cancer, and gastro intestinal cancer are 16. 44, and 4 excess deaths, respectively, per 1,000 workers exposed for 45 years at 2 f/cc. OSHA also estimated the risk of lung 601 (1980)) ruled that, prior to the. certainty." "A reviewing court [is] to cancer, mesothelioma, and- issuance of a new or revised standard give OSHA some leeway where its gastrointestinal cancer for 20-year and regulating occupational exposures to findings must be made on the frontiers 1-year durations of exposure to asbestos toxic materials, OSHA must make a , of scientific knowledge [and]... the at 2 f/cc. From this analysis. OSHA determination that a "significant" health Agency is free to use conservative estimates that the risk from all asbestos- risk exists and that the new standard. assumptions in interpreting the data related cancers among workers exposed will reduce or eliminate that risk. with respect to carcinogens, risking from 20 years to 2 f/cc is 44 excess OSHA's analytical approach to making error on the side of overprotection deaths per 1,000 workers. The estimated a determination that a significant risk of rather than underprotection" (448 U.S. at cancer risk from all cancers among material impairment exists from .655.656). workers exposed to 2 f/cc for one year GLEASON-000894