SCREENING OF THE CONTENT OF SOME HEAVY METALS AT THE HUMUS SOIL HORIZON OF THE TRANSCARPATHIAN REGION

Abstract

Based on the screening of some heavy metals (HMs) content in the humus soil horizon of the Transcarpathian region, the regularities of the distribution of HMs in the soils of different landscape zones have been established. It is shown that increasing of the terrain height, the content of HMs in soils decreases (except for Mn and Hg) and for the total HMs content the values of the Spearman correlation coefficient are: Cu – (-0.84); Zn – (-0.83); Mn 0.77; Mo – (-0.91); Co – (-0.82); Pb – (-0.83); Hg – absent; for the content of acid-soluble forms: Cu – absent; Zn – (-0.72); Mn 0.75; Mo – (-0.89); Co – (-0.86); Pb – (-0.77); Hg is absent. This pattern is associated with the tectonic and geological features of the different landscape zones. The calculation of the migration coefficient (the ratio of the content of acid-soluble forms to the gross content) has been shown that in mountainous regions this indicator has the highest value for Zn, Pb, and Cu. That means the potential danger of migration of these heavy me­tals and their bioavailability. This is probably connected to the type of soil in the mountai­nous areas of the region. A pronounced inter-element correlation of the HMs content in soils (except for Hg) has been established and the corresponding values of Pearson’s coefficients for the gross content are: Cu:Zn – 0,96; Cu:Mn – (-0,84); Cu:Mo – 0,89; Cu:Co – 0,99; Cu:Pb – 0,87; Zn:Mn – (-0,79); Zn:Mo – 0,91; Zn:Co – 0,96; Zn:Pb – 0,86; Mn:Mo – (-0,86); Mn:Co – (-0,84); Mn:Pb – (-0,75); Mo:Co – 0,87; Mo:Pb – 0,81; Co:Pb – 0,87. This makes it possible to predict the content of several HMs in the soils of the Transcarpathian region based on the results of determining one of them. In general, the content of HMs in the humus soil horizon (total content and content of mobile forms) is lower than the corresponding values of maximum permissible concentrations.