The human health effects of exposure to polybrominated biphenyls

Abstract

Polybrominated biphenyls (PBB) were inadvertently introduced into the food chain in Michigan in 1973. Fifty-one people with known exposure to PBB were studied. Twenty-three farmers with disabling health complaints, and 28 chemical workers involved in the PBB manufacturing process were systematically evaluated to determine if these highrisk groups suffered adverse effects from their known exposure to PBB. The farmers had a high frequency of constitutional symptoms, hepatomegaly and skin rashes, findings not commonly noted in the chemical workers. Biochemical and hematologic testing revealed few abnormalities, and electromyograms, nerve conduction velocities, endocrine studies, and lymphocyte transformation studies provided no objective findings that correlated with subjective complaints. There was no relationship between PBB levels and physical or laboratory abnormalities. Present evidence suggests that people exposed to PBB have few objective findings at this time, and reactive depression may be responsible for the high prevalence of constitutional symptoms.