Lead and zink in permafrost forest-steppe soils

Abstract

In this work lead and zinc in the soils of permafrost forest-steppe have been studied. It was revealed that the binding of heavy metals in the following descending series: Zn > Pb, which corresponds to the values of their clarks. Studies have shown that the binding of lead occurs mainly with the fulvic acids, and zinc -with the humic acids, which is associated with their chemical properties. The content of Pb and Zn in the rock turned out to be lower than in the soil, possibly due to biological accumulation. No signs of environmental pollution were found in the study area. The level of lead and zinc in plants and soil is not higher than the established norms. These data can be used to assess the ecological state of the area. Each plant has its own metal accumulation threshold determined by its biological characteristics. There are metals that are easily absorbed by plants. As a result, metals are unevenly distributed in the roots and overground mass, and create a decreasing chain of absorption: zinc comes first, then lead. It is possible that humic substances play the role of a barrier for lead, so its concentration in vegetation is low.