Thallium in the soils of southwestern Siberia

A relatively high content of thallium (1.5-3.0 mg/kg) is found in the soils (mainly, chernozems) of the southern part of Western Siberia. Minimal thallium concentrations are typical of the soils of the Baraba Lowland, and the highest concentrations appear in the soils of the Priobskoe Plateau. The distribution pattern of thallium in the soil profile is relatively monotonous. In the course of soil formation, a considerable part of thallium (up to 25% of the total thallium content) in the humus layer is extracted from the mineral material and gets fixed in the organic matter of soils.