ESTIMATING FISH CONSUMPTION RATES FOR ONTARIO AMERINDIANS

The routine assessment of human exposure to contaminants requires that exposure via consumption of freshwater fish be considered because man y chemicals persist and/or bioaccumulate in fish. Estimates offish con sumption rate were determined for Ontario Amerindians from data on the concentration of mercury in the hair of 4,327 Amerindians residing in 58 reserves across the province, combined with data on mercury concen trations in three commonly consumed species offish collected from lake s surrounding these reserves. Estimated rates offish consumption were found to differ between sexes, with males consuming a geometric mean o f 19 g offish per day, while females were estimated to consume a geome tric mean of 14 g/day. Fish consumption rate was found to increase wit h increasing latitude, a surrogate measure of community isolation, and to increase with age. Seasonal variation was also noted, with fish co nsumption rates being highest during summer months and lowest in winte r. These data may provide regulatory agencies with a more statisticall y representative basis upon which to establish assumptions concerning fish consumption rates for risk assessment purposes. Factors such as t he location of the exposed population, age and sex of exposed individu als, and time of year in which an assessment is being conducted, shoul d also be considered as specific situations require.