CONCENTRATIONS OF BLOOD AND HAIR MERCURY AND SERUM PCBS IN AN OJIBWAYPOPULATION THAT CONSUMES GREAT-LAKES REGION FISH

Objective: This paper describes an exposure assessment of an American Indian population using blood and hair samples as indicators of mercur y and polychlorinated biphenyl exposure from the consumption of fish t aken from the Great Lakes region. Methods: Questionnaires regarding fi sh consumption were completed by 89 Ojibwa tribal members. Mercury con centrations were determined in human hair and blood samples, and polyc hlorinated biphenyl concentrations were determined in serum. Results: Fish were consumed at the highest rates in April, May, June, and July. Lake trout, whitefish, and walleye were the preferred fish consumed b y 91.4% of the respondents. Concentration of blood mercury were all be low 55 mu g/L (ppb), while concentrations of mercury in hair were all less than 3 mg/L (ppm). Hair mercury concentrations were correlated wi th the previous year's fish consumption (p = .05). Dental amalgams and blood mercury concentrations were also significantly correlated (p < .002). Serum polychlorinated biphenyl concentrations, determined as th e sum of 89 congeners, were all below 9.6 ppb total polychlorinated bi phenyls. Subject age and total serum polychlorinated biphenyls were co rrelated (p < .001). Conclusions: The concentrations of mercury and po lychlorinated biphenyls in this Ojibwa population were relatively low, but several individuals were identified as having elevated concentrat ions and additional testing may be warranted. Since the accumulation o f contaminants was related to fish consumption and age, a long-term mo nitoring program that assesses chronic exposure to fish diets would be beneficial.