The triad approach to ecological assessment of urban soils

The “triad” approach was suggested by Chapman 22] for assessing the risk of contamination of bottom deposits. We applied this approach for the analysis of urban soils under different loads from motor transport. On its basis, the results of chemical analysis (heavy metals, biogenic elements, and pH), bioindication parameters of the communities of microorganisms, and the results of toxicological investigations with the use of test-organisms were generalized to obtain an integral index of the soil status (IS). A comparison of IS values for test plots at different distances from a highway in the city of Kirov (58.3729–58.624722 N, 49.3743–49.628611 E) showed that the ecological status of the soils could be qualified as disturbed on the plots adjacent to the highway and as slightly disturbed at distances of 30–200 m from the highway. The IS calculated on the basis of data of three disciplines (chemistry, ecology, and toxicology) seems to be a more comprehensive characteristic for assessing the ecological status of urbanozems as compared to Zc indices of the chemical contamination of soils (suggested by Saet) or indices of the integral biological characteristics of soil quality.