Determination of Hydroxylated Polybrominated Diphenyl Ethers in Blood from Baltic Grey Seals

Naturally produced hydroxylated polybrominated diphenyl ethers(OH-PBDEs)have been extensively studied in the lower end of the Baltic Sea food web.Certain OH-PBDE congeners have displayed increasing concentrations over the last 30 years in herring(Clupea harengus)from the Baltic proper.However,studies on the top carnivores in the Baltic Sea are scarce.Quantitative data on OH-PBDEs exist for ringed seal(Pusa hispida)from the Gulf of Bothnia,but only a limited amount of data have been produced with regard to Baltic grey seal(Halichoerus grypus),and seals from the Baltic proper.A method was developed and evaluated for quantification of OH-PBDEs in coagulated whole blood.The method was applied on blood obtained from dead grey seals originating from different parts of the Baltic Sea.The levels of OH-PBDEs were observed to be low in the analyzed seals in comparison with reported levels in white-tailed sea eagle nestlings(Halizeetus albicilla),and some Baltic fish species.The levels of the dominant congener,6-OH-BDE47,were statistically significantly higher in seals from the Baltic proper than in seals from the Gulf of Bothnia.Hydroxylated polychlorinated biphenyls(OH-PCBs)were observed to be of much higher concentration than the OH-PBDEs in the analyzed seals.The average concentration of the dominant OH-PCB congener,4-OH-CB107,was one order of magnitude greater than that of 6-OH-BDE47.