Different profiles of naturally produced and anthropogenic organohalogens in the livers of cetaceans from the Sea of Japan and the North Pacific Ocean

Levels and profiles of naturally produced halogenated bipyrroles (Br4Cl2-DBP and Cl-7-MBP), methoxylated tetrabromodiphenyl ethers (6-MeO-BDE47), anthropogenic perfluoroalkyl substances (PFASs) and legacy persistent organic pollutants (POPs) were investigated in the livers of 14 cetaceans from the Sea of Japan and the North Pacific Ocean. The concentrations of Br4Cl2-DBP (4 to 4900 ng/g-wet), Cl-7-MBP (16 to 3960 ng/g-wet) and 6-MeO-BDE47 (7 to 190 ng/g-wet) were higher in the order of killer whales > toothed whales > baleen whales. Profiles of PFASs were dominated by perfluoroundecanoic and perfluorotridecanoic acids (10 to 540 ng/g-wet), sum of which accounted for 70% of total measured PFASs. Regional difference was observed for Cl-7-MBP and PFASs, which were higher in the Sea of Japan, whereas Br4Cl2-DBP was in the North Pacific Ocean. Specific accumulation pattern of these natural contaminants in cetaceans around northern Japan could help compare the exposure profile of PFASs and POPs among other geographic regions.