Cancer incidence of dry cleaning, laundry and ironing workers in Sweden

Objectives This study investigated the risk of cancer among dry cleaners, launderers, and pressers in a large record-linkage study in Sweden. Methods The Swedish Cancer Register III contains nationwide data on cancer incidence between 1971 and 1989, by occupation and industry of employment, as reported in the 1960 and 1970 censuses. Dry cleaners, launderers, and pressers were compared with the remaining part of the employed population using multivariable Poisson regression models and standardized incidence ratios. Results Dry cleaners, launderers, and pressers employed in the laundry, ironing, or dyeing industry in both censuses showed an increased risk of Hodgkin's disease [relative risk (RR) 2.69, 95% confidence interval (95% CI) 1.01-7.19], an elevated risk of leukemia among women (RR 2.53, 95% CI 1.44-4.46), and increased risks of stomach (RR 1.80, 95% CI 1.05-3.11) and laryngeal (RR 2.42, 95% CI 0.91-6.45) cancers among men. The results of the analyses of launderers and dry cleaners as a separate occupational group reflected those of the whole exposure group, while pressers showed an elevated lung cancer risk (RR 1.67, 95% CI 0.75-3.72). Conclusions If they are not due to chance or confounding, the results of this study reflect either the potentiation of other carcinogens by solvents or direct effects. The results are limited by the use of job and industry titles as proxies for occupational exposures.