Concentrations and frequencies of polychlorinated biphenyl congeners in a Native American population that consumes Great Lakes fish

Objective: Polychlorinated biphenyl congener profiles were examined in serum samples from 61 Native American (Ojibwa) volunteers who regularly consumed fish harvested from the Great Lakes region. A total of 93 peaks are reported which represent 126 individual chlorobiphenyls. Results: When ranked by frequency, 13 peaks comprising single or co-eluting chlorobiphenyls occurred in all 61 samples (a frequency of 100%). These included chlorobiphenyls 138 + 158 + 163, 105 + 132 + 153, 180, 118, 196 + 203, 74, 182 + 187, 199, 183, 114 + 134, 195 + 208, 206, and 194. These 13 peaks also occurred at concentrations higher than those of all other measured chlorobiphenyls, except for the addition of the peak containing chlorobiphenyls 170 and 190, which was below detection in 15% of the samples and ranked fifth in average concentration. The highly chlorinated chlorobiphenyls resembled human serum profiles previously reported in the literature. Methods: Individual chlorobiphenyls were identified using a gas chromatograph equipped with a 60-meter DB-5 capillary column and electron capture detection. Conclusion: When compared to other human residue analyses for fish-eating populations, the Ojibwa samples contained higher proportions of lightly chlorinated and labile chlorobiphenyls such as 8, 16 + 32, 17, 18, 25, 41 + 64 + 71, 33, 52, 110, and 129. These proportions were similar to those found in carp, whitefish, or whitefish livers harvested from the Great Lakes region. These data indicate that regular meals of lower trophic level fish, such as whitefish from the Great Lakes, may distort steady-state human chlorobiphenyl profiles with respect to certain lightly chlorinated or labile chlorobiphenyls.