Selenium and Mercury Interactions with Emphasis on Fish Tissue

This review addresses the effects of mercury (Hg) in fish as it relates to the health of the fish themselves as well as potential risks of toxicity in wildlife and humans that consume fish. In particular, it addresses selenium (Se) as a bioindicator of susceptibility to harmful effects of Hg exposures and evaluates how Se moderates the toxic effects of Hg in a variety of test animals, emphasizing the importance of these potential effects in fish. A major conclusion of this review is that Hg toxicity risks to animal life cannot be accurately assessed without considering the moderating effects of Se. Therefore, Se:Hg molar ratios and their mathematical inverse are important factors that need to be considered when assessing risks from Hg exposures because exposures are related directly to toxicity outcome. In addition, actual measurement of both beneficial nutrients (e.g., Se, omega-3 fatty acids) and contaminants (e.g., Hg, polychlorinated biphenyls [PCB]) in fish tissue, rather than gross associations betw...