ARCTIC AIR-POLLUTION AND HUMAN HEALTH - WHAT EFFECTS SHOULD BE EXPECTED

Persistent contaminants such as heavy metals and organochlorine compou nds are transported from distant sources to the Arctic by oceanic and atmospheric currents. Natives inhabiting the Arctic can be exposed, be cause they exist at the highest trophic level of the arctic aquatic fo od chain, along which biomagnification of contaminants occurs. We revi ewed the data available on heavy metal and organochlorine body burden in natives from different regions of Nunavik (northern Quebec) and ass essed the potential risk of health effects. In addition, we investigat ed the relationship between each contaminant plasma level and omega-3 fatty acid content of plasma phospholipid, a surrogate measure for aqu atic food consumption. Cadmium exposure appears to be unrelated to the consumption of species from the aquatic food chain (r = 0.0004; P = 0 .99), whereas PCBs and mercury were (r = 0.49 and 0.52, respectively; P less than or equal to 0.0001). Mean blood mercury levels measured in northern Quebec natives were below those associated with significant neurological disorders. Typical daily intakes of dioxin-like compounds , PCBs, DDE, and dieldrin were estimated from the mean concentration i n milk fat and pharmacokinetic models. The calculated PCB intake (0.3 mu g/kg/day) exceeds the acceptable daily intake, with effects on repr oduction and development being the most relevant to assess in future e pidemiological studies.