Concentrations and chromatographic profile of DDT metabolites and polychlorobiphenyl (PCB) residues in stranded beluga whales (Delphinapterus leucas) from the St. Lawrence estuary, Canada

Samples of blubber, kidney, liver, lung and milk from 3 male and 1 female beach-stranded beluga whales were analysed. High resolution capillary gas chromatography showed more than 30 peaks corresponding to tetra-, penta, hexa- and heptachlorobiphenyls. PCP congener patterns were qualitatively similar in the various tissues, and resembled those of Aroclors 1254 and 1260. Concentrations of PCP's, p,p-DDE and total DDT residues were highest in blubber (59-72, 66-89, 76-104 ppm respectively). Corresponding concentrations in milk were 1.72, 1.88 and 204 ppm. There was no correlation between PCP, DDE and total DDT concentrations, and the fat content of kidney, liver and lung. Quantitative differences in organochlorine profiles suggested organ-specific retention of some PCP congeners. For example, 2,3,3,5,5,6-hexachlorobiphenyl and 2,2,3,3,5,6,6-heptachlorobiphenyl, which were minor compounds in blubber extracts, were relatively more abundant in kidney than in liver and lung tissue. The significance of congener-specific PCB analysis is discussed in terms of the structure-activity effects on PCP persistence and toxicity.