Lung cancer following exposure to chloromethyl methyl ether. An epidemiological study.

A historical prospective epidemiological study was conducted on workers exposed to chloromethyl methyl ether (CMME) containing 0.5% to 4% bis(chloromethyl) ether (BCME) as an impurity. The study period was 1948 to 1972. Follow-up procedures located 98.9% of the cohort, including those separated from the plant. The cause of death was established for 95.3% of the 278 known deceased men. A CMME exposure rating system was established from employees' work histories and recollections of supervisors. This system approximated relative exposure concentrations and duration times. Analysis on an age-specific basis revealed a relative risk of lung cancer 3.8 times higher in 669 exposed vs 1,616 unexposed workers, a significant increase. Although limited by lack of quantitative environmental sampling data, dose-response relationships were established between lung cancer an intensity and/or duration of exposure.