Use of Background Concentrations of Heavy Metals for Regional Monitoring of Soil Contamination by the example of Rostov Oblast

Abstract

In the monitoring of soils contaminated with heavy metals, the choice of the target indicators (background or threshold values) is a challenging task. The determination of the background concentrations is of practical importance, because the pollution of clean soils to the levels below the maximum permissible concentration (MPC) or the tentative permissible concentration (TPC) levels is not recorded and, hence, cannot be prosecuted. Background concentrations are rarely applied in pollution assessment, because they remain unknown in most cases. The study of the soils of specially protected natural areas in Rostov oblast has revealed the regional specificity of the soil cover—elevated concentrations of a number of heavy metals and other trace elements—related to their high concentrations in the parent materials. Therefore, it is impossible to apply current public health standards based on the total concentrations of elements, such as MPC and TPC, in the monitoring of soil contamination in Rostov oblast. The use of background values characterizing the soils of specially protected natural areas seems to be more promising for this purpose. For an adequate environmental monitoring, data on the background concentrations of trace elements in the virgin of slightly transformed soils of specially protected natural areas should be obtained with due account for the regional diversity of soils including their classification position, texture, and the character of parent materials.