LUNG-CANCER MORTALITY AND POLYNUCLEAR AROMATIC-HYDROCARBONS - A CASE-COHORT STUDY OF ALUMINUM PRODUCTION WORKERS IN ARVIDA, QUEBEC, CANADA

The authors report the results of a case-cohort study of 338 lung canc er deaths in 1950-1988 and a random sample (sub-cohort) of 1,138 from among 16,297 men who had worked at least one year between 1950 and 197 9 in manual jobs at a large aluminum production plant. In the past, ce rtain workers were exposed to substantial quantities of coal tar pitch volatiles, a mixture known to include polynuclear (polycyclic) aromat ic hydrocarbons, and thus suspected to be capable of causing lung canc er. After they controlled for the effects of smoking, the authors foun d that rate ratios rose with cumulative exposure to coal tar pitch vol atiles measured as benzene-soluble material to 2.25 (95% confidence in terval (Cl) 1.50-3.38) at 10-19 mg/m(3)-eears benzene-soluble matter, but did not rise further at higher exposures. The data are compatible with a linear relation with benzene-soluble matter (rate ratio (RR) = 1 +/- 0.031 mg/m(3)-years benzene-soluble matter). This model predicts a rate ratio of 1.25, and lifelong excess risk of 2.2%, after 40 year s exposure at the current hygiene standard (0.2 mg/m(3)). A curved rel ation (RR = 1 + 0.098 mg/m(3)-years benzene-soluble matter (0.7)) fitt ed somewhat better. Under this model, the predicted risks after this e xposure are higher: 1.42 and 3.8%. The data are compatible with both a dditive and multiplicative models for the combined effect of smoking a nd coal tar pitch volatiles.