Cardiovascular disease and environmental pollutants: the Arctic aspect

Environmental pollution in the Arctic is due to long range transport from lower latitudes or to local industrial activities. Since the latter are not different from point source exposure in the rest of the world the paper focuses on the former aspect which is the main type of environmental pollution in the western Arctic. The environmental pollutants of major significance are heavy metals (mercury, cadmium, lead) and persistent organic pollutants (PCB's, pesticides) and the main exposure is through the traditional diet of sea mammals (mercury, cadmium, persistent organic pollutants) and through smoking (cadmium). There is rather strong evidence that lead is a (weak) risk factor for high blood pressure even at low levels of exposure. Apart from lead there is little evidence that the above mentioned pollutants are significantly related to cardiovascular diseases. Since the pollutants, however, are found in the traditional diet together with n-3 polyunsaturated fatty acids, monounsaturated fatty acids, and selenium which are believed to promote cardiovascular health there is an indirect link between the pollutants and cardiovascular disease. This becomes relevant when dietary guidelines are developed for arctic populations. Epidemiological evidence from Greenland relevant for this discussion is presented, i.e. i) findings from a countrywide interview survey on dietary habits which show that sea mammals are widely consumed and appreciated for health and other reasons and that there is virtually no fear of pollution, and ii) mortality results which do not support the hypothesis that the low rate of ischemic heart disease in Inuit is due to their traditional diet.