Trace Element Concentrations of Three Soils in Central Appalachia

Abstract

Background concentrations of trace elements in soils are important due to recent interest in contamination potential and the toxic effect of these elements on humans and the environment. We assessed the trace element content of three major soil series in Major Land Resource Area (MLRA) 126 of the Appalachian region of the USA by two extraction techniques. Three pedons each of Upshur and Vandalia (both Typic Hapludalfs), and Gilpin (Typic Hapludults) soil series in three distinct areas of this region were described and sampled. Bulk density, texture, pH, cation exchange capacity (CEC), base saturation, and total C were determined for each described horizon. For the A, Bt, and C horizons of each soil series, concentrations of 10 trace elements (As, Ba, Cd, Cr, Cu, Mn, Ni, Pb, Se, Zn) were determined by ICP‐AES after microwave digestion by USEPA Method 3051 and an HF method. Trace element concentrations using USEPA 3051 were about 1.5 to 5 times lower than the amounts extracted by the HF method, except for Mn. Copper, Mn, and Ni were significantly higher in the Alfisols (Upshur and Vandalia) compared with the Ultisol (Gilpin) when extracted by the 3051 method, but only Ni was significantly higher in Alfisols with the HF method. No differences were found among soils for As, Ba, Cd, Cr, Pb, Se, and Zn using either extraction method. Average concentrations (mg kg−1) in A horizons of these soils for both Method 3051 and HF digestion were: As, below detection limits (BDL); Ba, 120, 255; Cd, 1.5, 3.0; Cr, 17, 22; Cu, 16, 31; Mn, 1470, 1360; Ni, 11, 19; Pb, BDL, 8; Se, BDL, BDL; and Zn, 65, 87. Based on the HF method, no elements exceeded the cumulative loading rate concentrations allowed by the USEPA 503 regulations. However, Cd concentrations were up to 10 times higher in these soils compared with similar soils in nearby areas, and exceeded the Northeastern U.S. Regional Research recommended values for waste material application.