» The ability to metabolize and excrete contaminants, including mercury, varies from person to person. The EPA formula for calculating "safe" fish consumption may not fully account for the uniqueness of individuals.

» The EPA formula only accounts for mercury exposure through fish consumption. People can also be exposed to mercury through dental amalgams, vaccines, accidents (e.g., broken thermometer), some ritual uses and in some work places.

» The calculator uses average concentrations of mercury or PCBs in tested fish. An average by definition reflects some fish with more contaminants and some with less.

» For commercial fish: Fish contaminant levels may vary from one water body to another. The Calculator uses best available data on fish contaminant concentrations, but cannot fully account for these regional differences. Also PCB data for commercial fish are mostly lacking, so recommendations are based on mercury only, except for salmon.

» For Minnesota freshwater fish: The Calculator uses data on fish contaminant concentrations from the Minnesota Department of Health. However, some of these data are older and PCB concentrations are not available for some species.