Mercury and selenium in the Brazilian subtropical marine products: Food composition and safety

摘要

In this study we estimate the content of mercury (Hg) and selenium (Se) in 32 fish and 6 shellfish species that represent the most intensively caught, consumed, and exported seafood species from the Brazilian subtropics. The mean Hg contents in three species of large carnivorous fish (i.e., shortfin mako; 502 mu g kg(-1); dusky grouper, 789 mu g kg(-1); school shark, 806 mu gkg(-1)) were above the allowable limit (500 mu g kg(-1)) for human consumption. However, the content of Se in the fin fish, as well as the shellfish, were substantially below (147 mu gkg(-1) = Se = 688 mu gkg(-1)) what is considered safe for human consumption (i.e., 2000 mu gkg(-1)). The only exception was in the deep-sea red crab sample, which exhibited an elevated Se content of ca. 5400 mu g kg(-1). Nevertheless, all studied species had mean Se:Hg molar ratios greater than 1:1, suggesting that human consumption of the studied sea food species are relatively safe with respect to their Hg content. The highest Se:Hg molar ratios were found in the shellfish species investigated, as well as the most sought after commercial fish. The calculated Se health benefit value index (Se-HBV, HBVSe), which is a qualitative measure of the ability of Se to mute the toxic effects of Hg, exhibited high positive values in most of the studied fish species, suggesting human consumption of these species was safe. An exception was sardine, an important species for producing canned fish, which exhibited the lowest HBV.