The Content of Lead in High-Molecular Organic Compounds of the Chernozems of Transbaikalia

Abstract

This article presents an analysis of the results of a study of the characteristics of lead binding by humic substances in the chernozems of the Selenga middle mountains of Transbaikalia (the headwaters of the Uda river) and of permafrost meadow chernozem soils (quasi-gley chernozems) in the south of the Vitim plat- eau. In the soils studied, the accumulation of lead does not depend on the amount in the soil-forming rock. Thus, in the organogenic horizon of chernozems, its content is 1.5 times lower than in the horizon C. In meadow chernozem soils, on the other hand, in the upper horizon the content of lead is much higher than in the underlying rock. A considerable part of the total lead content in the upper organogenic soil horizon is fixed by humic substances. Since lead is sorbed by fulvic acids, one can expect their migration down the soil profile, due to the high mobility of these acids, which should be taken into account in the future in the presence of obvious contamination. The content of Pb in the investigated soils and herbaceous vegetation does not exceed its clark values and available MPCs, i.e. this can serve as a reference for monitoring activities.