Epidemiologic study of workers exposed to acrylonitrile.

This retrospective cohort study of 1,345 male employees with potential for exposure to acrylonitrile analyzes cancer incidence and mortality from 1956 to 1976. Expected numbers based on company and national rates have been computed on person-years. The analyses consider calendar time, payroll classification, occupation, duration of exposure, severity of exposure, and latency. Overall, 25 cases of cancer occurred, with 20.5 expected based on company rates. Of these, eight were respiratory cancer cases, with 4.4 expected. Excesses were found primarily during the 1970-76 time period among wage roll employees who had worked during plant start-up. A trend toward increased risks was seen with increased duration and severity of exposure. Twenty cancer deaths were found, with 17.4 expected according to company rates. Since many cancer cases were recently diagnosed and are living, it may be premature to evaluate mortality statistics. These findings, coupled with results from tests in laboratory animals, raise the serious suspicion that acrylonitrile may be a human carcinogen.