PCBS HAVE DECLINED MORE THAN DDT-GROUP RESIDUES IN ARCTIC RINGED SEALS (PHOCA-HISPIDA) BETWEEN 1972 AND 1981

Mean DDT-group concentrations in the blubber of western Arctic ringed seals (Phoca hispida) sampled in 1981 were less than 1 mu g multiplied by (times) g** minus **1 wet weight blubber, and mean PCB concentrations were less than 2 mu g multiplied by (times) g** minus **1 wet weight. Males seals had higher concentrations that did females. PCB concentrations were about half of those in a sample of the same population taken in 1972, when allowance was made for the variation of residue concentrations with age, sex, and condition. This decline probably results from the ban of PCB manufacture and use imposed in the early 1970s. Concentrations of DDT-group residues did not show any clear decline over the same interval, and the relative proportions of p,p prime -DDT and p,p prime -DDE suggested that there is a continuing supply of DDT to the western Arctic.