A possible approach for setting a mercury risk-based action level based on tribal fish ingestion rates

Risks from mercury and other contaminants in fish for a large Columbia River dataset are evaluated in this paper for a range of consumption rates. Extensive ethnohistorical, nutritional, recent ethnographic surveys, and other documentation was reviewed to confirm previous determinations that the traditional subsistence fish consumption rate is 500 pounds per capita annually, or 620 g per day (gpd). Lower comtemporary consumption rates for other population subsets are also discussed. The causes of the current suppression of fish consumption are discussed and the cultural, educational, social, and trade and economic impacts of the loss of fish are considered. Action levels for mercury for riverine Tribes in the Columbia Basin are suggested at 0.1 ppm or less based on the combined risk from mercury plus other contaminants, the higher fish consumption rates, the existing cultural deficit due to loss of salmon and other stressors, the health benefits of fish, and the cultural and economic importance of fish. The goal of fish advisories is to reduce fish consumption even further, which shifts the burden of avoiding risk to the very people who already bear the burdens of contaminant exposure, socio-economic impacts and cultural loss. However, because Tribal communities often do not have the choice of giving up more food, income, religion, culture, and heritage in order to avoid contamination, they are forced into choosing between culture and health. Many tribal members choose to incur chemical risk rather than giving up their culture and religion. We believe that lowering the action level for mercury is part of the federal fiduciary responsibility to American Indian Tribes.