Human health implications of environmental contaminants in Arctic Canada: a review

This paper assesses the impact on human health of exposure to current level s of environmental contaminants in the Canadian Arctic, and identifies the data gaps that need to be filled by future human health research and monito ring. The concept of health in indigenous groups of the Arctic includes soc ial, cultural, and spiritual dimensions. The harvesting, sharing and consum ption of traditional foods are an integral component to good health among A boriginal people influencing both physical health and social well-being. Tr aditional foods are also an economic necessity in many communities. Consequ ently, the contamination of country food raises problems which go far beyon d the usual confines of public health and cannot be resolved by health advi sories or food substitutions alone. The primary exposure pathway for the co ntaminants considered in this paper is through the traditional northern die t. For the Inuit, the OCs of primary concern at this time from the point of view of exposure are chlordane, toxaphene, and PCBs. Exposures are higher in the eastern than in the western region of the North. For Dene/Metis, exp osure to OCs is in general below a level of concern. However, estimated int ake of chlordane and toxaphene has been found to be elevated for certain gr oups and is a cause for concern if exposures are elevated on a regular basi s. The developing foetus and breast-fed infant are likely to be more sensit ive to the effects of OCs and metals than individual adults and are the age groups at greatest risk in the Arctic. Extensive sampling of human tissues in the Canadian north indicate that a significant proportion of Dene, Cree and Inuit had mean maternal hair mercury levels within the 5% risk-range p roposed by the WHO for neonatal neurological damage. Based on current level s, lead does not appear to pose a health threat while cadmium is likely onl y a major risk factor for heavy smokers or consumers of large amounts of or gan meats. Consumers of traditional foods are exposed to an approximately s even-fold higher radiation dose than non-consumers of traditional foods due predominantly to the bioaccumulation of natural radionuclides in the food chain. Risk determination for contaminants in country food involves a consi deration of the type and amounts of food consumed and the sociocultural, nu tritional, economic, and spiritual benefits associated with country foods. Risk management options that minimize the extent to which nutritional and s ociocultural aspects of Aboriginal societies are compromised must always be considered. (C) 1999 Elsevier Science B.V. All rights reserved.