Mercury (Hg) in fish consumed by the local population of the Jaguaribe River lower basin, Northeast Brazil

Abstract

The knowledge of Hg concentrations in fish is of considerable interest since these organisms are a major source of protein to coastal human populations and fishing communities. The main source of human exposure to Hg contamination occurs through the consumption of fish. In this paper, we compare Hg concentration in 13 fish species from Jaguaribe River lower basin and an adjacent coastal region in the northeastern coast of Brazil. We sampled fish from three stretches of the river: fluvial, estuarine, and marine regions. We tested the hypothesis that Hg concentration in muscle tissue vary according to species, location, and trophic level. Significant differences were observed among species and trophic level, but these could not be observed among the regions studied. As expected, the highest concentrations were observed in carnivorous fish (5.6–107.5; 26.9±18.8 ng g−1 ). Hg concentrations observed in this study are similar to those observed in regions of low environmental contamination. We estimated Hg intake to vary between 0.02 and 0.22 ng Hg kg body weight−1 week−1 , for the average body weight of 56.7 kg, which was considered as low exposure and therefore, a low risk to consumers of fish from the regions studied.