The effect of heavy metals on the soil-earthworm-European mole food chain under the conditions of environmental pollution caused by the emissions of a copper smelting plant

摘要

The paper examines the effect of heavy metals on the soil-earthworm-European mole food chain in the area affected by the operation of the Middle Urals Copper Smelting Plant (MUCSP), located in Revda (Sverdlovsk region). Compared to the surrounding territory, in the polluted zone, the increase in the content level of physiologically essential elements (Cu and Zn) is less pronounced in the tissues of earthworms than in the soil, while the content level of nonessential elements (Pb and Cd) is higher in the tissues of earthworms than in the soil. The only biomagnification that has been revealed is that of Cd: the Cd content is 8-10 times higher in the tissues of earthworms than in the soil (3.9-4.5 times higher as compared to the litter) and 4-6 times more considerable in the liver of the mole than in the tissues of earthworms. Zn, Cu and Pb do not accumulate in the liver of moles, since their levels grow in the gastric contents, while a higher Cd level in food leads to the disproportionate accumulation of this substance in the liver. Even though there is an excessively high Cd content in the organism of the mole, this animal is the ultimate "depot" of this element in terrestrial ecosystems.