Contaminant levels in the world's northernmost harbor seals (Phoca vitulina)

•Legacy and currently used POPs were measured in harbor seals from Svalbard.•ΣPCBs, ΣDDTs, ΣCHLs, mirex, ΣHCHs and ΣPFSAs were lower than in southerly populations.•HCB, OH-PCBs and ΣPFCA concentrations were similar to harbor seals elsewhere.•60-90% decrease in PCBs, DDE and HCB in Svalbard harbor seals since 1999.•Relatively high levels of OH-PCBs in the harbor seals might affect thyroid homeostasis.

The world's northernmost harbor seal (Phoca vitulina) population, which inhabits Svalbard, Norway, constitutes a genetically distinct population. The present study reports concentrations of 14 PCBs, 5 chlordanes, p,p′-DDT, p,p′-DDE, hexachlorobenzene (HCB), mirex, and, α-, β-and γ-hexachlorocyclohexane (HCH) in blubber, and pentachlorophenol, 4-OH-heptachlorostyrene, 10 OH-PCBs and 14 perfluoroalkyl substances in plasma of live-captured harbor seals from this population (4 males, 4 females, 4 juveniles), sampled in 2009-2010. Concentrations of PCB 153, p,p′-DDE, oxychlordane, α-HCH and mirex and perfluoroalkyl sulfonates in Svalbard harbor seals were considerably lower than harbor seal from more southerly populations, while concentrations of HCB, OH-PCBs and perfluoroalkyl carboxylates were similar for harbor seals from Svalbard and southern areas. Concentrations of PCBs and pesticides in the Svalbard harbor seals were 60-90% lower than levels determined a decade ago in this same population. Current concentrations of legacy POPs are not considered a health risk to the harbor seals from Svalbard.