Occupational exposure to diesel and gasoline engine exhausts and risk of lung cancer among Finnish workers

BACKGROUND: Studies on engine exhausts and lung cancer have given inconsistent results. METHODS: Economically active Finns were followed-up for lung cancer during 1971-95 (33,664 cases). Their Census occupations in 1970 were converted to exposures to diesel and gasoline engine exhausts with a job-exposure matrix. The relative risks (RRs) for cumulative exposure (CE) were defined by Poisson regression, adjusted for smoking, asbestos, and quartz dust exposure, and socioeconomic status. RESULTS: RR for engine exhausts among men did not increase with increasing CE. In women, RR for gasoline engine exhaust was 1.58 (95% CI 1.10-2.26) in the CE-category of 1-99 mg/m(3)-y and 1.66 (1.11-2.50) among those with > or =100 mg/m(3)-y (lag 20 years). With a lag of 10 years RR for the middle/highest diesel exhaust category in women was 1.42 (0.94-2.13). CONCLUSIONS: Occupational exposure to engine exhausts was not consistently associated with lung cancer in this study, possibly due to low exposure levels.