Cancer Mortality in Workers Exposed to Organochlorine Compounds in the Pulp and Paper Industry: An International Collaborative Study

摘要

The objective of this study was to evaluate cancer mortality in pulp andpaper industry workers exposed to chlorinated organic compounds. Weassembled a multinational cohort of workers employed between 1920 and 1996 in 11 countries. Exposure to both volatile and nonvolatile organochlorinecompounds was estimated at the department level using an exposurematrix. We conducted a standardized mortality ratio (SMR) analysisbased on age and calendar-period–specific national mortalityrates and a Poisson regression analysis. The study population consistedof 60,468 workers. Workers exposed to volatile organochlorines experienceda deficit of all-cause [SMR = 0.91; 95% confidenceinterval (CI), 0.89–0.93] and all-cancer (SMR = 0.93; 95% CI, 0.89–0.97) mortality, withno evidence of increased risks for any cancer of a priori interest. There was a weak, but statistically significant, trend of increasingrisk of all-cancer mortality with increasing weighted cumulativeexposure. A similar deficit in all-cause (SMR = 0.94; 95% CI, 0.91–0.96) and all-cancer (SMR = 0.94; 95% CI, 0.89–1.00) mortality was observed in those exposedto non-volatile organochlorines. No excess risk was observed in cancersof a priori interest, although mortality from Hodgkin disease was elevated (SMR = 1.76; 95% CI, 1.02–2.82). In this study we foundlittle evidence that exposure to organochlorines at the levels experiencedin the pulp and paper industry is associated with an increasedrisk of cancer, apart from a weak but significant association betweenall-cancer mortality and weighted cumulative volatile organochlorineexposure.