EXPOSURE OF REMOTE MARITIME POPULATIONS TO COPLANAR PCBS

Two remote maritime populations were evaluated for their biological ex posure to organochlorines in 1989-1990. Because of their high intake o f seafood, these two populations have high biological levels. One hund red nine breast milk samples from Inuit women from Arctic Quebec were analyzed to determine levels of polychlorodibenzo-p-dioxins (PCDDs), p olychlorinated dibenzofurans (PCDFs), and coplanar polychlorinated bip henyls (PCBs) including non-ortho mono-ortho, and di-ortho congeners. Total 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEqs) for PCBs were 3.5 times higher in Inuit milk samples than in 96 Caucasian milk samples. Among the 185 fishermen from the Lower North Shore of the Gul f of the St. Lawrence River, we evaluated 10 highly exposed fishermen for their coplanar PCB Mood levels. Total TEqs were 900 ng/kg for high ly exposed individuals with 36 ng/kg for controls. In these two nonocc upationally exposed populations, coplanar PCBs make a larger contribut ion to the TEq than PCDDs and PCDFs. However, the mono-ortho penta CB No. 118 is the major contributor for the total toxicity.