Ecological peculiarities of cadmium dispersal at the urbanized terrain edaphotopes of the Steppe Dnieper region (shown by Dniprodzerzhinsk as an example)

Abstract

The objective of this research is the clarification of ecological peculiarities of cadmium dispersal at the urbanized terrain edaphotopes of Dniprodzerzhinsk. Heavy metals have been widely discussed in a huge number of researches. Special attention should be paid to cadmium as one of the most hazardous environmental toxic agents. There exist multiple data on cadmium content in various soil types of Ukraine, but until the present time there’s no full information as for the accurate geochemical behavior of cadmium in the soils, as well as for the priority impact of one or another soil property upon its concentration in certain soil types – natural ones or anthropogenically modified ones. The applicability of such researches is first of all determined by the necessity to decrease the hazardous environmental consequences of soil contamination with cadmium, as well as to improve the living conditions of the population. Evaluation of the technology-related impact upon the city soil layer is of current concern in terms of monitoring that is corresponding to the modern tasks for the environmental condition control. The article highlights the issue of ecological peculiarities of cadmium dispersal at the urbanized terrain edaphotopes of Dniprodzerzhinsk: variety of cadmium concentration being formed under the natural and anthropogenous influence in the soils of Dniprodzerzhinsk makes difficult to solve the problem of soil contamination with such chemical element. Soils with various content of cadmium can be found within the limits of the city, underneath the steppe vegetation. Content differentiation is attributed to rather diverse set of processes in the soil and to various properties of the soils. Edaphotopes of all studied right-bank urbanized terrains are cadmium contaminated to any extent. Cadmium content in the soil layer of the administrative districts of Dniprodzerzhinsk is ascending as follows: Dniprovsky district (0.6–9.9 mg/kg) – Bagliy district (1.0–10.5 mg/kg) – Zavodsky district (1.5–10.8 mg/kg). Evaluation of intensity of the technology-related geochemical abnormalities in the city soils has been provided by the abnormality level factor. The lowest (weak) soil contamination level can be observed within the edaphotopes of the left-bank area of Dniprovsky district of the city. High and very high soil contamination levels can be observed within the urbanized terrains of the right-bank part of the city at Bagliy and Zavodsky districts (eastern, central and western areas). Results of the statistical processing of the experimental material show the ratios of correlation of cadmium content and mechanical composition of the soil and humus. Absence of cadmium correlation with physical clay-fraction of soil, as well as close significant relation with humus enable us to associate its presence in the soils with biogenous accumulation, being also the evidence of the anthropogenous impact upon cadmium content in the soil layer.