Regional distribution of PCBs and presence of technical PCB mixtures in sediments from Norwegian and Russian Arctic Lakes.

The results of measurement of polychlorinated biphenyls (10 PCB congeners recommended by AMAP) in surface bottom sediments collected from 26 remote lakes in Northern Norway and 11 lakes in North Russia in 1994 and 1995 are presented. Cores were collected from the deepest part of each lake with a gravity corer. The north Russian lakes were shallow ponds less than 1 m deep, while the north Norwegian lakes and the lakes on the Svalbard Archipelago were usually 10-30 m deep. The sediment samples were analyzed by GC-high resolution MS analyses. The range of concentrations was wide. In sediment from the tundra ponds, summation operator PCB were generally low, ranging from 0.2 to 1.4 ng/g dry weight (dw), with one exception (19.3 ng/g dw). In sediments from the north Norwegian lakes and the lakes on Svalbard Archipelago, the concentration was ranging from 0.7 to 35.4 ng/g dw. The geographical distribution and possibility of geographic gradients of the summation operator PCB is discussed. The PCB composition is further analyzed by statistical methods to indicate possible presence and contribution of 10 various technical PCB mixtures (Chlorphens, Kanechlors, Arochlors, Sovols) in the samples.