Polybrominated biphenyls in lactating Michigan women: persistence in the population.

Polybrominated biphenyls (PBB) were inadvertently introduced into livestock feed in Michigan in 1973, resulting in widespread contamination of the state's food supply. Details of this unfortunate incident have been extensively documented (Carter 1976; Meester 1979). Approximately 12 months after the spill, several reports demonstrated the presence of PBB in human tissues including fat and blood serum as well as in breast-milk specimens (Brilliant et al. 1978; Landrigan 1980). Brilliant et al. (1978) described the distribution of PBB body burdens among a random sample of lactating women, and estimated that as many as 97 per cent of Michigan residents could be expected to have detectable levels of PBB. The distribution of PBB body burdens was skewed geographically, higher levels being found in the more populous lower peninsula. Other studies have suggested that levels of PBB in the Michigan population decrease with increasing distance from contaminated farms (Wolff et al. 1978) and appear to be higher in males and children (Wolff et al. 1982). There are insufficient data available to describe agespecific distributions.