Serpent River First Nation (SRFN) has been experiencing significant environmental, health, social, cultural, and economic impacts from uranium mining and milling with numerous decommissioned projects located on or nearby their traditional territory. The members of SRFN expressed concerns about the safety of their traditional foods. This study aimed to examine potential risks posed by the ingestion of various contaminants including uranium in local traditional foods, which may have been impacted by proximity to these industries.
The study involved three components: a dietary survey, a sampling program, and a human health risk assessment (HHRA). A food frequency questionnaire was administrated to gather information on traditional food consumption patterns. Samples of traditional foods, including mammals (moose, deer, and snowshoe hare), birds (partridge), fish (walleye, northern pike, yellow perch, and smallmouth bass), berries and plants, were anaylzed for various metals, including arsenic, cadmium, chromium, cobalt, lead, manganese, mercury, nickel, selenium, and uranium. Based on the collected data, a HHRA was conducted to assess potential health risks associated with the exposure to metals from traditional foods.
This study found that concentrations of metals in the majority of traditional foods samples were low and similar to concentrations measured in supermarket foods. Uranium levels in wild game and fish were below the laboratory method detection limit. Mercury levels in fish species were generally below the Health Canada guidelines of 0.5 ppm except for samples of walleye. Elevated levels of lead were found in wild bird samples, likely due to the use of lead ammunition. Also, cadmium concentrations were elevated in moose organs.
The HHRA demonstrated that, based on reported dietary patterns and levels of contaminants measured in the samples collected for this study, eating locally harvested traditional foods was safe. The study recommended that hunters should avoid using lead shots to minimize the exposure to lead that could be hazardous to both children and adults. Since cadmium naturally accumulates in moose kidneys and liver, adults should consume these organs only occasionally and in moderate amounts. However, children should avoid eating moose kidneys and liver altogether as should smokers since cigarette smoke also contains cadmium. There was minimal concern about mercury exposure. However, women of child bearing age and children were recommended to limit their consumption of large predatory fish (walleye and northern pike) in order to minimize their mercury exposure. Fish with lower levels of mercury, such as lake whitefish and sucker, are preferred for this population as are smaller sizes of predatory fish, like walleye and northern pike.