Polychlorinated biphenyl concentrations in cod-liver oil: evidence of a steady-state condition of these compounds in the Baltic area oils and levels noted in Atlantic oils

Abstract

A steady-state condition of polychlorinated biphenyl (PCB) pollution is evident in cod-liver oil samples of fish collected from the Baltic area between 1971 and 1989. Spatial differences in the concentration of congeners and isomers of these chemicals between the Baltic Sea and other areas in the north and northeastern part of the Atlantic Ocean appeared to be rather small. A site relatively distant from the PCB sources of the European continent, an open ocean environment near Iceland, showed a fivefold lower concentration of many PCB congeners than the Baltic Sea. The open and deep waters of the North Sea and Norwegian Sea differed by a factor of 2 in the total concentrations of PCBs when compared with the southern Baltic proper. Continuous release of PCBs into the atmosphere over Europe, its drift from distant sources in North America, and further aerial transport and deposition due to dominating air masses movement from the west and southwest are postulated to be the main routes of PCBs pollution and a reason for the small differences in concentration between the marine areas assessed.