Consumption of freshwater fish in Kahnawake: Risks and benefits

Kahnawake is a Mohawk community located on the south shore of the Saint Law rence River near Montreal. A comprehensive study was conducted in 1996-1997 to address the local concern regarding health risks of contaminant exposur e associated with freshwater fish consumption. Forty-two participants, incl uding most of the identified active fishermen (n = 33), were interviewed. W alleye, perch, bullhead, and smallmouth bass were the species most consumed . Average daily intake of locally caught fish was 23 g/day. Nutrient and co ntaminant levels of locally collected fish were analyzed. Fish were good so urces of protein, polyunsaturated fatty acids (particularly omega-3 fatty a cids), calcium, zinc, and iron. Levels of cadmium, lead, arsenic, polychlor inated biphenyls (PCBs), and other chlorinated pesticides were at least 10 times lower than the guideline levels. Mercury levels of some predatory fis h exceeded the guideline of 0.5 mu g/g. Average daily intakes of all contam inants were below the guideline levels by a factor of 10 except for mercury . Average mercury intake rate was about one-third that of the guideline lev el (200 mu g/week). Contrary to residents' perception, Kahnawake fish were not particularly contaminated. In view of the nutritional as well as cultur al benefits, fishing and fish consumption may be promoted. (C) 1999 Academi c Press.