Correlation between magnetic susceptibility and heavy metal concentrations in forest soils of the eastern Czech Republic

Abstract

Magnetic susceptibility measurements were performed on 2,000 samples of forest soils from the Ostrava-Karvina industrial region (Czech part of Upper Silesian Coal Basin) and the Moravian-Silesian Beskydy Mountains and their piedmont area, Podbeskydi. Concentrations of selected elements were determined in 1,200 samples from the same set. Industrial facilities (metallurgical industry and power plants) located in this region represent major sources of both magnetic particles and risk elements contaminating soils within the industrial region and neighboring mountainous areas. The magnetic susceptibility has a closely correlated relationship with Zn, Fe, As, Pb and Cu concentrations in soils. The magnetic susceptibilities vary inversely with distance from the sources. The behavior of individual chemical elements during transport and deposition was studied by means of ratios of concentrations of elements and values of magnetic susceptibility. Metals correlating very closely with magnetic susceptibility (Fe and Zn) were deposited together with dust particles, whereas Pb, As, and trace amounts of Zn can create independent particles which are components of long distance transport and deposition. The concentrations of Pb, As and, in part, Zn in soils are strongly dependent on the elevation of the sampling site; in the uppermost parts of mountains they are enriched. Other studied elements show neither relationship with sources of air pollution, nor with the geomorphology of the area. Concentrations of chemical elements V, Cr, Rb, Sr, U, Zr, Ca, Bi, Mn and Ti are related mostly to underlying sedimentary rocks.