Lung cancer risk in iron and steel foundry workers: A nested case control study in Asturias, Spain

Background Workers of iron and steel foundries have a high lung cancer risk but the findings on specific processes associated with this risk are incon sistent. We examined the risk of lung cancer among workers in the main indu strial processes of a large iron and steel foundry in Asturias, Spain. Methods We conducted a nested case-control stimy comprised of 144 male lung cancer cases and 558 controls, selected from a study base of about 24,400 workers employed in the industry between 1952 and 1995. Cases were identifi ed through linkage of industry records with those of two cancer registries. Controls were selected through industry records using incidence density sa mpling were matched to cases by age and date of birth and had to be alive a nd without king cancer at the time of selection. Smoking history was obtain ed through company medical records. Unconditional logistic regression was a pplied and all ORs were adjusted for age and tobacco consumption. Results Workers were, on an average, heavy smokers and a very strong relati on was observed for smoking (OR for "ever smoker" = 32.4). Workers having e ver been employed in the blast furnace had an excess hmg cancer risk (OR = 2.55, 95% CI 1.25-5.21) compared to a reference group of workers not employ ed in metal producing departments. A similar excess was observed for worker s having as their longest held job employment in the blast furnace. A two-f old risk was also observed for workers in the main foundry. For subgroups o f workers, tobacco smoking appeared to be an important positive or negative confounder: Conclusions In this large Spanish foundry, a high risk was observed for wor kers employed in departments with high exposure to crystalline silica, PAHs , and various other carcinogenic chemicals. Although comparisons were made between workers of the same industry, smoking habits differed and adjustmen t by smoking modified considerably the risk estimates. Am. J. Ind. Med. 38: 644-650, 2000. (C) 2000 Wiley-Liss, Inc.