Regularities of distribution of microelements in virgin and arable chernozem under the impact of mining

Abstract

The total content of trace elements Cu, Pb, Cr, Ba and Sr in soils and in parent rocks in the vicinity of a mining plant (Lebedinsky GOK) in virgin and arable areas composed of tittypic chernozems was studied. The studied trace elements are heavy metals and can enter the soil when fertilizing. The tailings dump of Lebedinsky GOK has the greatest impact on the site. The obtained results were compared with the clarks of soils, maximum permissible, approximately permissible and local background concentrations. In the studied soils, accumulation of Cu (Кк = 1.45-2.05) and Cr (Кк = 1.44-1.74) is most pronounced, while dispersion is typical of Sr (Кк = 0.49-0.87). In soil profiles, chromium is evenly distributed; the content of barium and lead in organic mineral horizons increases significantly. The content of strontium in the upper soil horizons is lower than in rocks. In the organo-mineral and in mineral horizons, the concentrations of chromium and barium are close to the MAC level: the excess is 0.87–1.03 for chromium and is 0.86–1.12 for barium. The contents of copper and lead are below 0.4 MAC and 0.3 MAC, respectively. The soil contamination assessment shows that there is low contamination with chromium, barium and copper. With respect to the contents of strontium and lead, the soils are classified as clean. In general, the soil pollution is tolerable, but there is a decrease in the soil pollution reference function of protected area. To enhance the reliability of the research results, it is necessary to solve a number of issues related to the development of MAC and AAC and background values of the contents of the studied elements.