Spatial heterogeneity of soil contamination оf urban systems with heavy metals

Abstract

The study determines the content of movable forms of heavy metals in the soils of Kherson on the territories (testing grounds) of different functional purposes: I testing ground – a selitable zone with multistory constructions, II testing ground – an industrial zone, III testing ground – a selitable zone with mixed constructions, VI testing ground – the zone of transport loads, V testing ground – the zone of a general urban center, IV testing ground – a selitable island zone, VII testing ground – a suburban zone. It establishes that the content of lead exceeds the emission limit 2-4 times, the content of cadmium exceeds the emission limit 2 times. The experiments found out that the main zones polluted by toxic chemicals were formed in the places of mass concentration of automobiles, the development of transport infrastructure objects and the activity of industrial enterprises. The estimation of the soil ecological condition was performed by the calculation of an aggregate pollution index, Zc,, according to it the condition of urban soils on VI, VII testing grounds was characterized as favorable, on I, II, V testing grounds – as satisfactory, on III, IV – as moderately dangerous. It was established that рН of the soil environment, meteorological conditions, the building density of the territory, the arrangement of road traffic also influence the degree of their migration and dispersion. The research results determined that the zones adjacent to the areas of surface water bodies are characterized by a satisfactory condition by the content of heavy metals, however, because of a high level of automobilization there is a risk of their entering the rivers Virovchyna, Koshova and Dnipro in the future. The study suggests the measures aimed at reducing anthropogenic pressing on the territories where the content of heavy metals exceeds the emission limit.

Keywords: soil, heavy metals, total indicator of pollution, mapping