Respiratory cancer among soap production workers.

Employment in the soap production industry in Italy has entailed some exposure to sulfuric acid vapors and nickel dusts, both agents under suspicion of being carcinogenic for the respiratory tract. A mortality study, together with an incidence study for laryngeal cancer, has been conducted among 361 men with a minimum employment of one year in soap production. Mortality from all causes was lower than expected, but lung cancer and laryngeal cancer deaths were increased, although without statistical significance. Five new laryngeal cancer cases were detected during the study period, while about one was expected. All the men with respiratory cancer had been working for several years, and the latency time was greater than 10 years. Even though the mechanism of a causal link is difficult to assess, the possibility of a carcinogenic effect of sulfuric acid is suggested.