Equations for assessing the total contamination of soils with heavy metals and metalloids

Cities and industrial regions are usually subjected to the impact of multi-element pollution, which requires the comprehensive characterization of the soil contamination with heavy metals and metalloids. The Saet index is the most popular among soil scientists and geochemists, because is supported by a system of critical values of the contamination hazard. However, with the use of this index, some questions arise that need to be clarified. It is recommended to make allowance for only the accumulated elements (with Kk(crit) > 2) and to assess only the elements with Clarke values above 1 mg/kg. We propose a new index of the total soil contamination that takes into account the different toxicity of the heavy elements and that is based on the calculation of the average geometrical values of the Kk concentration coefficients. Saet’s system of critical values of the contamination hazard may be used for this index.