Inuit Exposure to Organochlorines through the Aquatic Food Chain in Arctic Quebec eric Dewailly, Pierre Ayotte, Suzanne Bruneau, Claire Laliberte, Derek C.G. Muir,3 and Ross J. Norstrom4 'Public Health Center, Laval University Hospital, Ste-Foy, QC G1V 2K8 Canada; 2Kativik Regional Council of Health, Kuujjuaq, QC, JOM 1CO Canada; lFreshwater Institute, Department of Fisheries and Oceans, Winnipeg, MB, R3T 2N6 Canada; 4Canadian Wildlife Service, Environment Canada, Hull, QC, KlA OH3 Canada The contamination of the arctic aquatic food chain by organochlorine compounds has been brought to light through the last decade (1-4). These contaminants are anthropogenic organic compounds which include pesticides (e.g., lindane, chlordane, endrin, dieldrin, toxaphene, DDT), indus- trial compounds, and byproducts of various industrial processes [e.g., hexachloro- benzene (HCB), polychlorinated biphenyls (PCBs), polychlorodibenzo-p-dioxins (PCDDs), and polychlorodibenzofurans (PCDFs)]. Despite regulatory actions adopted since the late 1970s in North America and Western Europe to limit their release into the environment, these com- pounds are still being emitted because of U or U improper storage and disposal and on-go use in other parts of the world. Once released into the environmen middle and lower latitudes, organochlori reach the Arctic via long-range atmosph transport, waterways, and ocean curre (1). High lipophilicity and resistance biodegradation allow their bioconcen tion in fatty tissues of organisms. Throi the arctic aquatic food chain, biomagnif tion takes place, resulting in relatively b levels of contaminants in predator spe located at the top of the food chain (p4 bear, beluga) (2,3). Concentrations DDT, PCBs, toxaphene, and chlordan4 sea mammal blubber from the Canad Arctic are generally between 1 and 5 F r or w U. 70 Fg. 1. Map of arctic Qu6bec showing sampling locations. Arctic Qu6bec is situated between 55 ar north. Approximately 6500 Inuit inhabit 14 settlements scattered along a 2000-km shore line. The reg hospitals are located in Povungnituk and Kuujjuaq. Polar bear and beluga were sampled in Hudson arctic char in Hudson Strait, and ringed seal in Hudson Bay, Hudson Strait, and Ungava Bay (map so Energy, Mines and Resources Canada). )ing it at ines Leric ents e to tra- (ugh ica- :IL isgn toou . as . n.u muuo; ostnun; orxg;o- .: ... .:: .::. .. ... .:.:.:...: ::: :: : .::: cies chlorine compounds;"d o 1y lorinated bi- :::..:: ::.: :..::.: .:.::^:.:.::. :: .J .......: .:.:.:::.: .: o : *:::::.... . ;. : ::: :: of 620(93 :.: ....: .:::: .:.:: ..: .:: :: .: ....: ... : .: e in lian (lipid basis) (4). In polar bear fat, PCB ig/g concentrations ranging from 3 to 8 pg/g (lipid basis) have been reported (5). For cultural and economic reasons, the Inuit from arctic Quebec (Fig. 1) rely heavily on country foods for their subsis- tence. Based on data pertaining to harvest- ed marine species collected in 1982 and 1988 (6), their daily consumption of ringed seal, bearded seal, muktuk (beluga skin), and walrus amounts to approximate- ly 300 g per day. Knowing the contamina- tion levels reported in the edible tissues of sea mammals and their estimated daily consumptions, one would anticipate a rela- tively high body burden of organochlorine contaminants for native people living in arctic Quebec. Indeed, we reported in 1989 preliminary data which showed that the breast milk of Inuit women from the Address correspondence to E Dewailly, Environ- 4o. mental Health Service, Public Health Center (Quebec region)-CHUL, 2050 Boulevard Rene- Levesque, Ste-Foy, QC, G1V 2K8 Canada. We thank L. Ferron (Quebec Toxicology Center) for the organochlorine analysis, S. Gingras and D. Belanger for the statistical analysis, and Hdl&ne Careau for reviewing the manuscript. We are indebted to the nurses and midwives from the regional hospitals of Kuujjuaq and Povungnituk for the milk sample collection and the interviews. This work was supported by the Department of id 630 Indian Affairs and Northern Development Canada gional and the Minist&re de la Sante et des Services Bay, Sociaux du Quebec. )urce: Received 17 June 1993; accepted 2 September 1993. Environmental Health Perspectives 618