MERCURY LEVELS IN THE CREE POPULATION OF JAMES BAY, QUEBEC, FROM 1988TO 1993 94/

Background: High levels of mercury in the Cree population of James Bay , Que., have been a cause of concern for several years. This study exa mines changes in mercury levels within the Cree population between 198 8 and 1993/94 and identifies potential determinants of high mercury le vels. Methods: Data on mercury levels among the Cree were obtained thr ough a surveillance program undertaken by the Cree Board of Health and Social Services of James Bay. In 1988 and again in 1993/94 surveys we re carried out in all 9 Cree communities of northern Quebec. Hair samp les were obtained and analysed for mercury content. Analyses were carr ied out to determine the proportion of people who had mercury levels i n excess of established norms. Changes in mercury levels between 1988 and 1993/94 and determinants of high levels were estimated by means of regression methods. Results: The proportion of the Cree population wi th mercury levels in excess of 15.0 mg/kg declined from 14.2% in 1988 to 2.7% in 1993/94. Wide variations in mercury levels were observed be tween communities: 0.6% and 8.3% of the Eastmain and Whapmagoostui com munities respectively had mercury levels of 15.0 mg/kg or greater in 1 993/94. Logistic regression analyses showed that significantly higher levels of mercury were independently associated with male sex, increas ing age and trapper status. There was a correlation between the mercur y level of the head of the household and that of the spouse. Interpret ation: Mercury levels in the Cree of James Bay have decreased in the r ecent past. Nevertheless, this decrease in mercury levels may not be p ermanent and does not necessarily imply that the issue is definitively resolved.