The Mercury and Low Molecular-Weight Antioxidants Levels in Ungulates of the Republic of Karelia

Abstract

The high toxicity of mercury (Hg) poses a danger to the environment and humans, but studies of the concentration of this metal in organisms of terrestrial ecosystems are few. Ecotoxicologists also pay little attention to studying the role of antioxidant vitamins in protecting cells from toxic metals. The Republic of Karelia is one of the northwestern regions of Russia, the biogeochemical features of which can contribute to an increase in the mobility and bioavailability of Hg in food chains. The purpose of the work was to determine the concentration of Hg in the liver, kidneys, muscle and hair of ungulate mammals of the Republic of Karelia (wild boar Sus scrofa L. and moose Alces alces L.) and to analyze the relationship between the level of this toxic metal and the content of low molecular-weight antioxidants—reduced glutathione, retinol and α-tocopherol. Species and tissue-specific of the studied parameters in wild boars and moose are noted. The observations discovered by other researchers that omnivorous species accumulate more Hg in their tissues compared to herbivores, and also that this toxic metal is predominantly accumulated in the kidneys, while muscles contain a minimal amount, have been confirmed. Hg concentrations in most samples of liver and kidney of wild boars and in all samples of the same organs of moose were within the limits recorded for domestic pigs and deer, respectively. The levels of Hg we recorded in the tissues and hair of wild boars and moose were generally comparable to or lower than the levels of this metal noted in animals from other regions of Russia and other countries of the world. In wild boars and moose of Karelia, no statistically significant relationships were found between the Hg level and the content of the studied antioxidants in the internal organs. Moose were characterized by a higher content of α-tocopherol in the body than wild boars, which is a feature of this type of herbivorous ungulate mammal. The results of the study indicate a relatively low level of mercury pollution in terrestrial ecosystems in Karelia.