Chemical contaminants and parasites: assessment of human health risks associated with consumption of whitefish (Coregonus clupeaformis) from two boreal lakes in northern Saskatchewan, Canada.

In Canada there is increasing concern about potential effects of industrial activities on wildlife and human health. In an interdisciplinary study concentrations of inorganic (metals, metalloids) and organic (PCBs, organochlorine pesticides) contaminants, and parasitic infections of lake whitefish (Coregonus clupeaformis) from Montreal and Reindeer lakes, Saskatchewan, were investigated to assess human health risk related to fish consumption. In both lakes contamination of fish with chemical substances and compounds, respectively, were very low and often close to detection limits. Lake whitefish parasite communities consisted of 15 (Montreal Lake) and 12 (Reindeer Lake) species most of which were found in the intestinal tract. Many parasite species showed seasonal differences in prevalence and/or mean intensity of infection. None of the identified parasites are known to be human-pathogenic and overall, whitefish from both locations can be considered safe and healthy food. Nevertheless, women of child-bearing age and young children should limit their consumption to 3 and 2 meals, respectively, of Reindeer Lake whitefish per week to minimize potentially harmful exposure to mercury. As well, intestines of Montreal Lake fish should be removed prior to fish consumption if large parasite cysts containing a yet unidentified cestode species are detected.