Predatory bird species show different patterns of hydroxylated polychlorinated biphenyls (HO-PCBs) and polychlorinated biphenyls (PCBs)

Hydroxylated metabolites of polychlorinated biphenyls (H0-PCBs) have previously been associated with endocrine disrupting effects. Since metabolic capacity may differ among species, we investigated the levels and profiles of HO-PCBs and PCBs in livers of four predatory bird species from Belgium. Maximum concentrations for sum HO-PCBs were found in the common buzzard (Buteo buteo) up to 13 700 pg/g wet weight (ww). The most prominent H0-PCB congener in all bird species was 4-H0-CB 187 (up to 6420 pg/g ww in buzzard liver), followed by 4-H0-CB146 in the buzzard (upto 1820 pg/g ww), sparrowhawk (Accipiter nisus), and grey heron (Ardea cinerea), and by X-H0-CB138 in long eared owl (Asio otus) and in one grey heron (up to 985 pg/g ww and 3450 pg/g ww, respectively). The mean profile of the grey heron differed from the other species with 3'-H0-CB138 and 4-H0-CB163 contributing more to the sum H0-PCBs. This indicates that aquatic and terrestrial predatory bird species may show differences in their H0-PCBs profiles. Variation in the diet and species-specific accumulation and metabolism of PCBs are probably the most important causes for these differences. Correlations between H0-PCBs and their parent PCBs were only found significant for buzzards.