Assessment of Mercury Concentration in Turtles (Podocnemis unifilis) in the Xingu River Basin, Brazil

Abstract

Many studies on mercury contamination in aquatic biota deal with the effect of consuming metal-contaminated organisms on human health. In this study, we examined the factors that cause mercury contamination in Podocnemis unifilis in the Xingu River Basin of Mato Grosso and Pará States, Brazil. We quantified by atomic absorption spectroscopy with cold vapor the total mercury (THg) content in the liver and muscle samples of 50 Podocnemis unifilis specimens collected from the basin. The liver and muscle samples contained 134.20 ± 119.30 ng g−1 THg and 24.86 ± 26.36 ng g−1 THg, respectively. Each chelonian or meal has, on average, 5.34× more Hg than the highest level established as acceptable. From the results it can be inferred that, given the weekly consumption of chelonians, the riverine and indigenous communities in the Xingu River Basin are at risk of chronic consumption of Hg in amounts beyond the acceptable limit. The potential high risk to the health of this population is evident; however, the risk classification needs to be further studied.

Total Mercury Content in the Tissues of Freshwater Chelonium (Podocnemis expansa) and a Human Health Risk Assessment for the Amazon Population in Brazil

“…Toxic metals entering the river body would be absorbed in sediments and migrate to the sediment and biota through a biological and chemical process [59,60], so researchers began to pay more attention to pollution by toxic metals [61,62].…”