CANCER AMONG A MICHIGAN COHORT EXPOSED TO POLYBROMINATED BIPHENYLS IN1973

The long-term health effects of human exposure to polybrominated biphe nyls are not known. In this nested case-control study, we evaluated th e association between site-specific cancer risk and serum polybrominat ed biphenyl levels among a Michigan cohort accidentally exposed to pol ybrominated biphenyls in 1973. The Michigan Department of Public Healt h has followed 3,899 people through 1993, among whom 195 primary cance rs were identified in 187 persons. Controls were 696 randomly selected cancer-free individuals who were frequency matched to cases by sex an d age (in 5-year strata). Baseline serum polybrominated biphenyl level s were measured using standard methods. We found an increasing dose-re sponse relation for digestive system cancer risk with higher serum pol ybrominated biphenyl category [4-20 parts per billion (ppb), 21-50 ppb , and >50 ppb] after adjustment for age, family cancer history, cigare tte smoking, alcohol drinking, and baseline serum polychlorinated biph enyl level. Adjusted odds ratios (ORs) for each category were 8.23 [95 % confidence interval (CI) = 1.27-53.3], 12.3 (95% CI = 0.80-191), and 22.9 (95% CI = 1.34-392), respectively. Univariate analysis for polyb rominated biphenyl level and lymphoma risk also showed a dose-response relation, with corresponding ORs of 3.24 (95% CI = 0.24-95.9), 20.5 ( 95% CI = 1.51-608), and 32.6 (95% CI = 3.33-861).