Mortality and Exposure Response among 14,458 Electrical Capacitor Manufacturing Workers Exposed to Polychlorinated Biphenyls(PCBs)

摘要

We expanded an existing cohort of workers(n = 2,588)considered highly exposed to polychlorinated biphenyls(PCBs)at two capacitor manufacturing plants to include all workers with at least 90 days of potential PCB exposure during 1939-1977(N = 14,458).Causes of death of a priori interest included liver and rectal cancers,previously reported for the original cohort,and non-Hodgkin lymphoma(NHL),melanoma,and breast,brain,intestine,stomach,and prostate cancers,based on other studies.METHODS:We ascertained vital status of the workers through 1998,and cumulative PCB exposure was estimated using a new job exposure matrix.Analyses employed standardized mortality ratios(SMRs;U.S.,state,and county referents)and Poisson regression modeling.RESULTS:Mortality from NHL,melanoma,and rectal,breast,and brain cancers were neither in excess nor associated with cumulative exposure.Mortality was not elevated for liver cancer [21 deaths;SMR 0.89;95% confidence interval(CI),0.55-1.36],but increased with cumulative exposure(trend p-value = 0.071).Among men,stomach cancer mortality was elevated(24 deaths;SMR 1.53;95% CI,0.98-2.28)and increased with cumulative exposure(trend p-value = 0.039).Among women,intestinal cancer mortality was elevated(67 deaths;SMR 1.31;95% CI,1.02-1.66),especially in higher cumulative exposure categories,but without a clear trend.Prostate cancer mortality,which was not elevated(34 deaths;SMR 1.04;95% CI,0.72-1.45),increased with cumulative exposure(trend p-value = 0.0001).CONCLUSIONS:This study corroborates previous studies showing increased liver cancer mortality,but we cannot clearly associate rectal,stomach,and intestinal cancers with PCB exposure.This is the first PCB cohort showing a strong exposure-response relationship for prostate cancer mortality.