Selenium Content in Freshwater and Marine Fish from Southern Brazil Coastal Plain: a Comparative Analysis on Environmental and Dietary Aspects

The coastal plain of Rio Grande do Sul is considered to be a Se-deficient region in terms of its population dietary habit, making it the focus of this study. Selenium dietary deficiency is a concern when we consider its potential critical health effects on the local population. Therefore, this study contributes new information on the levels of Se in several species of marine and freshwater fish in the region of the Patos-Mirim Lagoon system, coupled with a comparative analysis of the metalloid contents between both fish groups. The Se contents in the fish species ranged from 88 ± 13 to 688 ± 19 μg.kg^-1. The average Se concentration in the muscle tissue of the freshwater species (251 ± 96 μg kg^-1) was significantly lower than that of the marine species (412 ± 143 μg kg^-1). Likewise, no evidence of Se biomagnification was found among the fish from both the marine and freshwater environments, suggesting the absence of trophic transfer of Se. We note that to ensure that the RDA (Recommended Daily Allowance, 55 μg day^-1) of Se dietary intake for adults is met, at least 134 g of freshwater or 82 g of marine fish fillet could be incorporated into the diet of the population of Rio Grande do Sul. According to target hazard quotients (THQ) and the permissible safety limits, consumption of the fish species analyzed is safe for human health.