Evaluation of total mercury concentrations in fish consumed in the municipality of Itaituba, Tapajos River Basin, Para, Brazil

The environmental exposure to mercury by riverine and Indian communities can occur through the ingestion of fish and products contaminated by mercury compounds. The present study aims to evaluate the total mercury concentration in the different fish species most consumed in the municipality of Itaituba, Tapajos river basin, where there are intense gold-mining activities. These fish samples were analyzed by atomic absorption spectrophotometry by cold vapor technique, Automatic Mercury Analyzer HG-3500. The largest mercury concentrations were found in the carnivorous species, ranging from 112.4 to 2250 mu g/g, while the detritivorous, herbivorous and omnivorous species presented total mercury levels ranging from 3.2 to 309.8 mu g/g, which is below the limit established by the World Health Organization. This paper also reports and identifies which species are more polluted and present a statistical relationship among concentration and weight of the carnivorous species studied in detail, Brachyplatystoma flavicans (dourada) (r(2) = 0.691) and Pseudoplatystoma sp. (surubim) (r(2) = 0.654). (C) 2000 Elsevier Science B.V. All rights reserved.