Exposure of inuit in Greenland to organochlorines through the marine diet

High organochlorine concentrations have been found among the Inuit in easte rn Canada and in Greenland. The present study was undertaken to assess the exposure to organochlorines in relation to age, sex, and diet in a general population sample of Inuit from Greenland. Survey data and plasma concentra tions of 14 polychlorinated biphenyl ( PCB) congeners and 16 pesticides, in cluding 5 toxaphene congeners, were recorded in a random population survey of 408 adult indigenous Greenlanders. In a two-stage design, the survey res ponse rate was 66%, and 90% of those randomly selected for blood testing pa rticipated. This was equivalent to an overall response rate of 59%. The med ian plasma concentration of the sum of PCB congeners was 13.3 mug/L; the li pid-adjusted value was 2109 mug/kg. The PCB concentration was twice as high as among the Inuit of Nunavik, Canada, 25 times higher than in a control g roup from southern Canada, and several times higher than the values found i n European studies. Concentrations were similarly elevated for all PCB cong eners and pesticides. The PCB congener pattern was similar to previous obse rvations from the eastern Canadian Arctic and Greenland. Concentrations sho wed statistically significant positive associations with age, marine diet, and male sex in multiple linear regression analyses. The exceptionally high plasma concentrations of several organochlorines among the Inuit of Greenl and are attributed to a lifelong high intake of seafood, in particular mari ne mammals. Concentrations of PCB adjusted for the consumption of marine fo od increased until approximately 40 yr of age, which is equivalent to the b irth cohorts of the early 1950s. The age pattern indicates that bioaccumula tion of PCB started in the 1950s, which is a likely date for the introducti on of the compounds into the Arctic environment.