Cancer Produced by Nonoccupational Asbestos Exposure in the United States

Open Access
Publisher Website
Google Scholar
Abstract
There is considerable evidence of asbestos fibers in the general environment, and asbestos fibers can be found In the lungs of most adults In urban areas of the western world. Concentrations in large urban areas appear to average around 3 ng/m3 of air and in rural areas around 0.1 ng/m3 of air. For the entire U.S. population it can be estimated that the average population exposure is 1.5 ng/m3. Based on the results of case control and other studies, It is estimated that about a third of the 1000 or so cases of malignant mesothelloma that occur In the U.S. each year appear to be related to this type of nonoccupational asbestos exposure. This Is a lifetime risk of 100 per million population. Lung cancer caused by asbestos In the general environment can be estimated from linear extrapolations of dose-response data arising from occupational studies. Using data from a study of retired asbestos products workers it Is estimated that the lifetime risk of lung cancer due to continuous asbestos exposure at 1.5 ng/m3 Is 2 per million. Possible causes for a fifty-fold difference between lung cancer and mesotheliomas caused by nonoccupational exposure to asbestos are discussed. These estimates are compared with estimates derived from a recent report commissioned by the West German government.