MONO-ORTHO AND NON-ORTHO SUBSTITUTED PCBS IN ARCTIC RINGED SEAL (PHOCA-HISPIDA) FROM THE SVALBARD AREA - ANALYSIS AND DETERMINATION OF THEIR TOXIC THREAT

To determine the 2,3,7,8-tetrachloro-dibenzo-p-dioxin (2,3,7,8-TCDD) t oxic equivalent (TEQ) of the PCBs in ringed seal, we analysed liver, b lubber and kidney for non-ortho and mono-ortho substituted CBs as well as the total PCB and total DDE concentration. The blubber samples wer e compared with ringed seal blubber samples from another study1,2 in w hich total PCB and PCDD/PCDF concentrations were measured, and the TEQ values for the PCBs in our samples were 11 times higher than the TEQ values for the PCDDs/PCDFs in the other seal samples. Comparing the 3 different seal matrices, we found no significant difference in PCB pat tern; the absolute concentrations expressed per unit lipid weight were for the females in the following order : blubber = liver > kidney. We found another order for the males: blubber > liver > kidney. Among th e different seals, there was a good PCB-sex correlation indicating tha t the results of different studies, without specific background inform ation, must be compared with great caution.