title: 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.
abstract: 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.
authors.affiliation: Norwegian Polar Institute, Polar Environmental Centre, 9296 Tromsø, Norway. heli.routti@npolar.no
authors.forename: Heli
authors.initials: H
authors.lastname: Routti
authors.forename: Bert
authors.initials: B
authors.lastname: van Bavel
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Letcher
authors.forename: Augustine
authors.initials: A
authors.lastname: Arukwe
authors.forename: Shaogang
authors.initials: S
authors.lastname: Chu
authors.forename: Geir W
authors.initials: GW
authors.lastname: Gabrielsen