Home – Home – Jornals – Geography and Natural Resources 2022 number 2

The X-ray fluorescence, atomic absorption and step-by-step extraction methods were used to obtain novel data on chemical composition of soils as well as on the forms of the heavy metals Cu, Pb and Zn residing in them. The key areas in the surroundings of the village of Utulik (southern shore of Lake Baikal) were surveyed. It was found that the contents of trace elements in these soils varied mainly within the regional background. However, the soils experiencing anthropogenic load are contaminated with Cu, Pb and Zn. The calculated coefficients of radial differentiation of elements in the soils of the conditionally background area showed an accumulation of lead (R > 1) in the O and E horizons, zirconium in the E horizon as well as chromium and iron in the B horizon. These soils are characterized by the removal of elements Cu, Ni, Co, Zn and Mn (R < 1). In samples soil from the conditionally background area, Cu, Pb and Zn occur mostly in forms poorly absorbed by plants. Furthermore, Zn is weakly fixed in polluted soils and basically occurs in exchange forms, and the role of amorphous hydroxides increases substantially in the fixation of Pb. Because of light granulometric soil composition and low sorption capacity of geochemical barriers, the presence of abundant amounts of Zn and Pb in exchange forms presents a potential threat to their migration to contiguous environments. An assessment of the buffer capacity of soils was made, indicating that the buffer capacity is medium (20.5-24.5 numerical points) or low (<20) with respect to heavy metals. These characteristics should be taken into account when monitoring the soil state and planning any economic activity.