Occupational risk factors for lung cancer: a case-control study in West Germany.

BACKGROUND The aim of this study is to evaluate carcinogens and occupations suspected to cause lung cancer and to generate new hypotheses about occupational risks. METHODS In a hospital-based study 1004 incident lung cancer cases and the same number of population controls matched for region, sex and age were interviewed between 1988 and 1993 for their smoking and occupational history. Exposure assessment was based on 33 job-specific supplementary questionnaires. Conditional logistic regression was used to calculate odds ratios (OR) and to control for smoking and occupational asbestos exposure. RESULTS Lifelong prevalence of exposure to asbestos was 20.5% for exposure of more than 940 lifetime working hours among controls, corresponding to an OR of 1.62 (95% confidence interval [CI] : 1.28-2.05) that was reduced to 1.45 after adjustment for smoking (P < 5%). Statistically elevated risks after adjustment for smoking and asbestos were seen in metal production and processing workers, transportation workers and freight handlers, in the rubber and plastics industry, in metal production, in engine and vehicle building, and installation. Significantly increased OR after adjustment for smoking and asbestos that deserve further attention were seen in plastics processing workers (OR = 3.49), and sheet and structural metal workers (OR = 2.01 and 2.37, respectively). CONCLUSIONS The results of the study confirm previously described occupational risks. Because of the possibility of controlling for occupational asbestos exposure, the study gives clear indications for prevention and further research.