Mercury and selenium concentrations in skeletal muscle, liver and regions of the heart and kidney in bearded seals from Alaska

Mean concentrations of total mercury [THg] and selenium [TSe] (mass and molar based) were determined for five regions of the heart and two regions of the kidney of bearded seals (Erignathus barbatus) harvested in Alaska in 2010–2011. Mean [THg] and [TSe] of bearded seal liver and skeletal muscle tissues were used for intertissular comparison. Se:Hg molar ratios were used to investigate elemental associations and potential antioxidant protection against Hg toxicosis. Age was an important factor in [THg] and Se:Hg molar ratios in heart and kidney. Small, but statistically significant differences in mean [THg] occurred among some of the five heart regions (p < 0.05). Mean [THg] was highest in liver at 3.057µg/g and lowest in heart left ventricle at 0.017µg/g. Mean [THg] ranked: liver > kidney cortex > kidney medulla > skeletal muscle > heart left ventricle (p < 0.001). Mean [TSe] was highest in liver at 3.848µg/g and lowest in heart left ventricle at 0.632µg/g. Mean [TSe] ranked: liver > kidney cortex > kidney medulla > skeletal muscle > heart left ventricle (p < 0.001). Se:Hg molar ratios were significantly greater than 1.0 in all tissues (p < 0.001) and represented baselines for normal [TSe] under relatively low [THg]. Mean Se:Hg molar ratios ranked: heart left ventricle > kidney medulla > kidney cortex (p < 0.001). This article is protected by copyright. All rights reserved