Lung cancer risk in male workers occupationally exposed to diesel motor emissions in Germany

Background Although in several epidemiological studies exposure! to diesel motor emissions (DME) shows an elevated lung cancer risk, it is still contr oversial whether DME is a human carcinogen. Methods In a pooled analysis of two case-control studies on lung cancer in Germany a total of 3498 male cases with histologically or cytologically asc ertained lung cancer and 3541 male population controls were included Inform ation about lifelong occupational and smoking history was obtained by quest ionnaire. Drivers of lorries, buses, taxies, diesel locomotives and forklif t trucks, bulldozers, graders, excavators, and tractors, were considered as exposed to DME and their cumulative exposure was estimated. All odds ratio s were adjusted for smoking and asbestos exposure. Results The evaluation of lung cancer risk for all jobs with DME-exposure c ombined showed an odds ratio of OR = 1.43 (95%-CI : 1.23-1.67). Most pronou nced was the increase in lung cancer risk in heavy equipment operators (OR = 2.31 95%-CI: 1.44-3.70). The risk of tractor drivers increased with lengt h of employment and reached statistical significance for exposures longer t han 30 years (OR = 6.81, 95%-CI: 1.17-39.51). The group of professional dri vers (e.g., trucks, buses, and taxies), showed an increased risk only in We st Germany (OR = 1.44, 95%-CI: 1.18-1.76), but not in East Germany (OR = 0. 83, 95%-CI: 0.60-1.14). DME-exposure in other traffic related jobs (e.g., d iesel engine locomotive drivers, switchmen, forklift operators) was associa ted with an odds ratio of OR = 1.53 (95%-CI: 1.04-2.24). Conclusions The study provides further evidence that occupational exposure to diesel motor emissions is associated with an increased lung cancer risk. Am. J. Ind. Med. 36:405-414, 1999. (C) 1999 Wiley-Liss, Inc.