ORGANOCHLORINE AND POLYCHLORINATED BIPHENYL LEVELS IN PINNIPED MILK FROM THE ARCTIC, THE ANTARCTIC, CALIFORNIA AND AUSTRALIA

This study presents levels of organochlorines and polychlorinated biphenyls in pinniped milk samples collected from four geographical regions. These regions include the Arctic, the Antarctic, California and Australia. Twenty milk samples from five species of pinnipeds were analyzed for organochlorines and polychlorinated biphenyls. Analyzes were carried out by high resolution gas chromatography/electron capture (HRGC/ECD) and high resolution gas chromatography/low resolution mass spectrometry (GC-MS). All samples had detectable levels of p,p'-DDE(DDE) with geometric mean (geom. mean) values ranging from 12 ug/kg in Antarctic fur seals to 1400 ug/kg in California sea lions. Geom. mean values reported for DDE in northern hemisphere pinniped milk ranged between 14 and 118 times larger than values reported for southern hemisphere pinniped milk. In addition every sample contained detectable levels of PCBs; the primary congeners reported include 99, 118, 153, 138, 180, and 187. Geom. mean values reported for the sum of these six congeners range from 6.78 ug/kg in Antarctic fur seals up to 360 ug/kg in northern elephant seals from California. Pinniped milk samples from California contained the highest overall levels of organochlorines and polychlorinated biphenyls. DDT (and metabolites), chlordane compounds, and dieldrin were also detected in most samples with a wide range of levels reported.