TRACE-ELEMENT CONTAMINATION OF SOILS IN THE INDIANA DUNES

Potential soil contamination by aerosol fallout and rainout and subsequent surface accumulation of trace elements in four soils in the Indiana Dunes have been evaluated based on chemical analyses using XRF and NAA and data from the literature. Among the studied elements, Se, Sb, Zn, and As show highest concentrations in aerosols relative to the soils. The surface accumulation of trace elements in the soil is a function of the proximity to the pollution sources, vegetation, and the organic matter content of the surface horizon. In the studied soils, presence of humus is essential for the retention of trace elements added by aerosols. Enrichment in the Ah horizon compared to the B horizon is, in decreasing order, evident for Mn, SB, Zn, As, Cs, Se, Cr, Fe, and Co. Contaminant Mn, Sb, As, Se, and possibly Zn have migrated into the E horizon. Bioaccumulation of trace elements has been insignificant in view of apparent input of the elements by deposition, possibly with the exception of Se.