(Table 1) Concentrations of the main organochlorine pesticides in liver and plasma samples of ringed seals (Phoca hispida)@en

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.本研究针对两种环斑海豹（Phoca hispida）种群——低污染的斯瓦尔巴种群与污染程度更高的波罗的海种群——的肝脏与血浆中有机氯农药（organochlorine pesticides）及其代谢物的浓度与分布模式展开了调查。在所检测的OCPs中，p,p'-滴滴伊与总氯丹类化合物的浓度最高。随着肝脏污染物浓度升高以及外源性物质代谢酶活性增强，3-甲磺酰基-p,p'-滴滴伊的浓度与五氯酚/六氯苯的浓度比值均显著上升，同时毒杀芬的组分分布模式愈发偏向持久性的Parlar-26与Parlar-50，而非更易生物降解的Parlar-44。相较于波罗的海种群的环斑海豹，斯瓦尔巴种群海豹体内氯丹代谢产物氧氯丹与七氯环氧化物相对于总氯丹类化合物的相对浓度更高；而顺式九氯与反式九氯的相对浓度则呈现相反的变化趋势。本次观测到的两种群海豹体内有机氯农药分布模式的差异，可能与外源性物质代谢酶的催化活性以及膳食暴露途径的差异密切相关。