Puzzling elevation of blood lead levels among consumers of freshwater sportfish

The authors evaluated lead exposure of Canadians (Montreal) who fished the nearby St. Lawrence River. From screening interviews conducted with l,118 f ishers on-site during the winter and fall of 1996, the authors selected 60 Montrealers who consumed at least one sportfish meal per week and 72 who co nsumed less than one sportfish meal per week. Fishers at the higher level o f sportfish consumption had elevated blood lead concentrations, compared wi th fishers who ate little sportfish (geometric mean = 57.4 mug/l vs. 48.2 m ug/l, respectively; p < .05). This result was surprising inasmuch as fish i s not considered a significant source of lead. In addition to sportfish con sumption, age, sex, occupation, smoking, and waterfowl consumption also sho wed independent associations with blood lead levels. Among frequent (i.e., greater than or equal to 1 meal/wk) consumers of sportfish, ingestion of wa terfowl was associated with higher blood lead levels (geometric mean = 69.4 mug/l vs. 51.8 mug/l, respectively; p < .05); this association was not pre sent for infrequent consumers. In multivariate analysis, the association of higher blood lead levels with sportfish consumption could be accounted for in large part by waterfowl consumption among frequent consumers of sportfi sh.