LUNG-CANCER RISK AND WELDING - RESULTS FROM A CASE-CONTROL STUDY IN GERMANY

In a case-control study, 839 male hospital-based cases of primary lung cancer and the same number of population-based controls-matched by se x, age, and region of residence-were personally interviewed for their job and smoking histories. The study allows to quantify occupational a sbestos exposure that was thought to be a welding-associated risk: 6% of cases and 2% of controls were classified into the occupational cate gory ''welders or burners'' (odds ratio [OR] = 2.65). This OR was redu ced to 1.93 (95% confidence limit [CL]: 1.03-3.61) after adjustment fo r smoking and asbestos. In contrast a history of welding in general fo r at least a half-year is 28% among cases and 23% among controls, yiel ding an OR of 1.25 (95% CL: 0.94-1.65) after adjustment for both confo unders. The OR of welding for more than 6,000 hr is 1.45 (95% CL = 1.0 4-2.02), reduced to 1.10 after adjustment for smoking and asbestos. Ox yacetylene welding for more than 6,000 hr lifelong is associated with an OR of 1.86 (95% CL = 1.01-3.43) reduced to 1.46 (n.s.) after adjust ment for smoking and asbestos. The risk of oxyacetylene welding seems to be highest for oat cell carcinoma with an adjusted OR for ever-expo sure of 1.46 (95% CL = 0.69-3.10). Therefore, the present study suppor ts the hypothesis that some, but not all, of the excess risk of welder s observed in the literature may be due to a history of cigarette smok ing and occupational asbestos exposure. The elevated risk for the subg roup of employees in the aircraft industry reported for the midterm ev aluation of the study still prevails, though no longer statistically s ignificant. However; employees in this industry who ever welded show a n OR of 2.29 (95% CL = 1.19-4.42) after adjustment for smoking and asb estos. (C) 1998 Wiley-Liss, Inc.