Occurrence and effects of selenium in the environment - a literature review

The literature review has revealed that the chemical forms of Hg and Se are important in the toxicology and the interactions between mercury and selenium. The research summarised in the report clearly demonstrates that there is an effect on fish. However, no literature data was found on the lastingness of the inhibiting effect of Se on Hg accumulation. The data on retention of Se in the water mass indicates that the removal of Se is a fairly slow process in oligotrophic clearwater lakes, while incorporation of Se in primary producers of eutrophic lakes causes selenium losses to the sediments. The literature shows that most of the selenium in the fish is taken up from the food, and that Selenium is effectively biomagnified. It also seems like fish are as sensitive as lower organisms for certain Se-exposure. Finally, the known toxic effects thresholds for selenium impacts on food-chain organisms are much higher than the dietary effect levels for fish