Evaluation of Soil Pollution by Potential Toxic Elements in Cultivated Land in the Poyang Lake Region Based on an Improved Matter–Element Extension Model

Abstract

This study examined the pollution status of potential toxic elements (PTEs) in cultivated soils throughout the Poyang Lake region, Jiangxi Province, China. A total of 251 topsoil samples were collected from the 0–20 cm depth to determine the concentrations of seven PTEs (Hg, As, Pb, Cd, Cu, Cr, and Zn). Based on the concentrations of PTEs, we constructed an improved matter–element extension model to evaluate the level of soil pollution by PTEs. We also applied Hakanson’s toxic response factor to correct the weights of PTEs determined by a conventional weighting method. The mean concentrations of all seven PTEs in the soil samples exceeded their local background values in Jiangxi Province. The over-standard rates of different PTEs were ranked in the order of Cr > Cu > Cd > Hg > Zn > Pb > As (36.2–87.9%). These potentially harmful pollutants mainly came from the surrounding industrial and agricultural areas, and could enter cultivated soils through different pathways. Samples from Duchang County, Hukou County, and Gongqingcheng City were in a clean state, whereas samples from other areas was in a still clean state or at the warning limit. The evaluation results were consistent with those obtained using several conventional methods. The improved matter–element extension model can therefore be applied for the evaluation of soil pollution by PTEs and yield reliable results in cultivated land.