Polychlorinated terphenyl patterns and levels in selected marine mammals and a river fish from different continents

Polychlorinated terphenyls (PCTs) are a class of persistent organic pollutants which have been used from the 1920s to the 1980s for similar purposes as polychlorinated biphenyls (PCBs). Comparably little data was available on the PCT distribution in the environment mainly due to analytical difficulties in their determination. By means of a calculation algorithm recently developed we now studied the PCT pattern in individual marine mammal samples and one fish sample from different continents. Altogether, 97 PCTs were detected in eight samples and twelve to 66 tetra- to nonachloroterphenyl (tetra- to nonaCT) congeners were detected in individual samples. PCTs were present in all marine mammal samples which originated from four continents, but the PCT pattern was varied. TetraCTs were dominant in the sample from Africa, Australia, Spitsbergen (European Arctic) and in a sample from the Baltic Sea, heptaCTs in samples from the North Sea and octaCTs in a sample from Iceland. The abundance of sumPCTs relative to PCB 153, estimated from the GC/ECNI-MS response corrected for the degree of chlorination, ranged from 0.9 to 8.8%, corresponding with ~0.22-2.2% of the total PCB content. The highest PCT level detected was 980 mg/kg lipid in a harbour seal from the North Sea, Germany. The results from this study indicated that samples from certain areas, e.g. the North Sea may still be polluted with PCTs.