Polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyles (PCBs), hydroxylated and methoxylated-PBDEs, and methylsulfonyl-PCBs in bird serum from South China.

Polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), and their derivatives, hydroxylated (OH) and methoxylated (MeO) PBDEs and methylsulfonylated (MeSO(2)) PCBs, were measured in sera of eight bird species collected from an e-waste recycling region in South China. Concentrations of summation operatorPCBs, ranging from 38 to 1700 ng/g lipid weight (lw), were one to two orders of magnitude higher than concentrations of summation operatorPBDEs (0.64-580 ng/g lw). The significantly positive relationship between PCB and PBDE concentrations suggested a similar pathway of exposure to these compounds. Compared with muscle in birds, serum might prefer to accumulate and/or retain less brominated/chlorinated congeners. 3-OH-BDE47 and 2'-OH-BDE68 were detected in more than 80% of the collected bird serum samples (range: not detectable (nd) to 13 and nd to 7.8 ng/g lw, respectively). The other three OH-PBDE congeners (4'-OH-BDE-17, 6-OH-BDE47, and 4'-OH-BDE-49) and two MeO-PBDE congeners (3-MeO-BDE47 and 6-MeO-BDE47) were occasionally detected in bird sera at concentrations ranging from nd to 2.5 ng/g lw. Both natural sources and metabolic transformation of PBDEs could contribute to the presence of these PBDE derivatives in the birds. The two MeSO(2)-PCB congeners (4-MeSO(2)-CB49 and 4-MeSO(2)-CB101) under investigation were detected at respective concentration ranges of nd to 12 and nd to 0.68 ng/g lw. 4-MeSO(2)-CB101 exhibited the highest concentration among the nine PCB and PBDE derivatives studied, indicating that biotransformation via the mercapturic acid pathway of PCBs might have occurred in the studied bird species.