Concentrations of selected PCB congeners in pike ( Esox lucius, L.) and arctic char ( Salvelinus alpinus, L.) in Finland

Abstract

PCBs were widely used in the 1970s in Finland. PCB usage was regulated the following decade and is presently strongly restricted. The reduction of PCB loading is generally observed as decreasing concentrations in environmental indicator species. The decreasing trend is seen clearly in the 25-year-long monitoring of northern pike in large lakes. The level of PCBs was approximately 5 to 15 μg g −1 (lipid weight) in the early 1970s, while present concentrations generally range from 0.5 to 3 μg g −1(l.w.). In recent years, increasing concern about the pollution of Arctic areas by airborne contaminants has led to an expansion of monitoring of persistent contaminants in northern areas. Arctic char ( Salvelinus alpinus, L.) has been used as a circumpolar indicator species in the fresh water of the Arctic Monitoring and Assessment Programme. The level of PCBs in char was determined in two small subarctic lakes in northern Finland and were 0.1 and 0.5 μg g −1(l.w.). There are several possible reasons for the variation between lakes: population density; growth conditions; nutrient level, and catching time. The PCB congener pattern is very similar in the fish samples of all large lakes and one small subarctic lake in spite of wide geographical coverage. The dominant congeners in these samples are IUPAC nos., 153, 138, 180, 118, 101.