Mortality among workers exposed to polychlorinated biphenyls.
Sinks-T; Steele-G; Smith-AB; Watkins-K; Shults-RA
Am J Epidemiol 1992 Aug; 136(4):389-398
Mortality rates among workers exposed to polychlorinated biphenyls (PCBs) were investigated through a retrospective cohort study. The workers had been employed at a factory that manufactured electrical capacitors containing PCBs. The study cohort consisted of 2742 men and 846 women (total 3588) who had worked at the factory for at least 1 day between January 1957 and March 1977. Personnel records and data were obtained from the company's files. Vital status was determined through the Social Security Administration. A proportional hazards model was used to determine whether a dose response relationship existed between PCB exposure and mortality from malignant melanoma or brain cancer. Results showed that overall mortality was lower than expected (192 deaths, standardized mortality ratio (SMR) 0.7. This was also true for heart disease and accidents. The SMR for cancer was also lower than expected (54 deaths, SMR 0.8). The SMR for skin cancer was elevated (eight deaths, SMR 4.1). All skin cancer deaths were due to malignant melanoma. An increase in brain and nervous system cancer was also evident (five deaths, SMR 1.8). This excess mortality applied to both sexes. All eight melanoma deaths and five brain cancer deaths occurred 5 or more years after initial employment. The proportional hazards analysis showed that on average, brain cancer cases had more than twice the estimated cumulative PCB dose than the comparison group, and had worked in close proximity to the impregnation ovens. The authors conclude that an association between employment at this factory and malignant melanoma and brain cancer seems to be evident.
NIOSH-Author; Cancer-rates; Epidemiology; Electrical-workers; Mortality-data; Polychlorinated-biphenyls; Occupational-exposure; Skin-cancer
American Journal of Epidemiology