Organochlorine Pesticides and Polychlorinated Biphenyls in the Subcutaneous Adipose Tissue of Beluga Whales ( Delphinapterus leucas ) of the White, Kara and Bering Seas

The OCP and PCB contents in the tissues of beluga whales ( Delphinapterus leucas ) from the Russian Arctic have been studied for the first time. Skin and subcutaneous adipose tissue samples collected in the White, Kara, and Bering seas in 2012–2017 were analyzed for the animals of different age and sex ( n = 22). 4,4'-DDE dominated among the OCPs analyzed; the main PCB congeners were PCB-138+PCB-158 and PCB-153 + PCB-168, which was also typical of other Arctic marine mammals. The highest concentrations and widest range of these compounds were found in beluga whales from the White Sea (4,4'-DDE: 3778.3 ± 4856.3 ng/g lipids; ranging as 33.2–16 007.8 ng/g lipids; PCB-138 + PCB-158: 1270.1 ± 1528.8 ng/g lipids; ranging as 127.6–4957.4 ng/g lipids; PCB-153 + PCB-168: 1144.1 ± 1230.2 ng/g lipids; ranging as 113.0–4515.2 ng/g lipids). The lowest concentration was found in the beluga whales from the Anadyr estuary of the Bering sea (4,4'-DDE: 1003.3 ± 1422.1 ng/g lipids; ranging as 186.0–3125.0 ng/g lipids; PCB-138 + PCB-158: 95.0 ± 99.2 ng/g lipids; ranging as 29.9–242.1 ng/g lipids; PCB-153 + PCB-168: 114.8 ± 118.8 ng/g lipids; ranging as 35.4–290.9 ng/g lipids). The biological parameters of the sampled animals, the features of PCB and OCP transport pathways, as well as regional environmental pollution, were considered the main reasons for the observed geographical variability of pollutant concentrations in beluga whales.