The present study investigates the concentrations and patterns of organochlorine pesticides (OCPs) and their metabolites in liver and plasma of two ringed seal populations (Phoca hispida): lower contaminated Svalbard population and more contaminated Baltic Sea population. Among OCPs, p,p'-DDE and sum-chlordanes were the highest in concentration. With increasing hepatic contaminant concentrations and activities of xenobiotic-metabolizing enzymes, the concentrations of 3-methylsulfonyl-p,p'-DDE and the concentration ratios of pentachlorophenol/hexachlorobenzene increased, and the toxaphene pattern shifted more towards persistent Parlar-26 and -50 and less towards more biodegradable Parlar-44. Relative concentrations of the chlordane metabolites, oxychlordane and -heptachlorepoxide, to sum-chlordanes were higher in the seals from Svalbard compared to the seals from the Baltic, while the trend was opposite for cis- and trans-nonachlor. The observed differences in the OCP patterns in the seals from the two populations are probably related to the catalytic activity of xenobiotic-metabolizing enzymes, and also to differences in dietary exposure.

Concentrations given per g wet weight. Chlordane = sum of cis-heptachlorepoxide, cis-chlordane, oxychlordane, trans-nonachlor/MC6 and cis-nonachlor; Toxaphene = sum of Tox 2, Parlar-26, -38, -40/-41, -44, -50, -62; Organochlorine pesticides = sum of pp-DDE, chlordanes, toxaphenes, HCB. Data extracted in the frame of a joint ICSTI/PANGAEA IPY effort, see http://doi.pangaea.de/10.1594/PANGAEA.150150

Supplement to: Routti, Heli; van Bavel, Bert; Letcher, Robert J; Arukwe, Augustine; Chu, Shaogang; Gabrielsen, Geir W (2009): Concentrations, patterns and metabolites of organochlorine pesticides in relation to xenobiotic phase I and II enzyme activities in ringed seals (Phoca hispida) from Svalbard and the Baltic Sea. Environmental Pollution, 157(8-9), 2428-2434