Relation of DDE and PBB serum levels in farm residents, consumers, and Michigan Chemical Corporation employees.

Results of serum PBB determinations on 524 Michigan diary farm residents and consumers of products from the farms, 55 chemical workers, and 56 Wisconsin farm residents are reported. Mean and median values were highest for the chemical workers, followed by consumers from and residents of quarantined and nonquarantined farms. Serum DDE was higher among chemical workers, but was similar for all other groups. Statistical analysis of serum of PPB and serum DDE levels was done with respect to quarantine status, age, sex, and obesity. The most significant correlate with PBB was quarantine status. Serum DDE, age, sex, or obesity were not consistently correlated with serum PBB. For DDE, age was invariably the most significant correlate. Both serum PBB and DDE were higher in males than females in husband-wife pairs in most cases, although the differences occurred less frequently among older age groups. These results support the hypothesis that PBB exposure was a recent interim exposure whereas DDE exposure has been cumulative throughout a person's lifetime. Higher PBB and DDE mean concentrations in serum of Michigan Chemical workers suggests an occupational exposure to these chemicals.