Total mercury (Hg-T) concentration in marketable fish in different seasonal periods at Ver-o-Peso Market, Belém, Pará State, Brazil

Abstract

The aim of this study was to determine the total mercury (THg) concentration in marketable fish at Ver-o-Peso market in Belém, Pará State, Brazil. The selected fish species for this study were Brachyplatystoma rousseauxii, Brachyplatystoma filamentosum and Schizodon fasciatum. Ten samples of each species were acquired in May 2011 (less rainfall) and November 2012 (the rainiest season). Analyses of THg were performed by atomic absorption spectrophotometry Hg201 in the Laboratório de Toxicologia Humana e Ambiental do Núcleo de Medicina Tropical da Universidade Federal do Pará. The averages in the first and second collections of B. rousseauxii were 0.45 µg/g and 0.09 µg/g of THg, respectively. Among the samples of B. filamentosum, the average was 0.31 µg/g and 0.30 µg/g. In specimens of S. fasciatum, only in the first period was observed a concentration of 0.01 µg/g. While the connection between THg concentration and Balanced Nutrition Index™ of species, only in samples of B. rousseauxii were found moderate positive correlation (r = 0.6, p> 0.05 for the two periods listed) no correlations were observed in other samples. Although no species has reached values beyond Brazilian Health Surveillance Agency recommendations, it is important to consider the cumulative effect of mercury in the body. The absence or moderate correlation found suggests the need for further studies to a better understanding about the nutritional index of fish and mercury contamination.