Development of Regional Maximum Permissible Concentrations of Oil, Lead, Chromium, Nickel, and Copper in the Ordinary Black Soils of Central Ciscaucasia

Contamination of ordinary chernozems of the Central Ciscaucasia with oil, lead, chromium, nickel and copper leads to a deterioration in their biological indicators. A significant decrease in the number of microflora, enzymatic activity and inhibition of the state of plants was established. The ecotoxicity sequence of heavy metals for ordinary black soils of Central Ciscaucasia is the following: Cr > Pb ≥Cu ≥ Ni. Ordinary black soils of Central Ciscaucasia, compared to similar black soils of Western Ciscaucasia, are somewhat less resistant to pollution with chromium, but are more resistant to pollution with copper and nickel. Resistance to pollution with lead and oil is the same. Regional maximum permissible concentrations of oil, lead, chromium, nickel and copper have been set for ordinary black soils of Central Ciscaucasia, based on disruptions of the environmental and the agricultural functions of the soil