Potential risks of heavy metals in agricultural soils and their source analysis in Yingtan City, Jiangxi Province

Abstract

Heavy metal pollution in agricultural soil is a serious phenomenon, which not only endangers food security but also threatens human health. Yingtan City, located in northeastern Jiangxi Province, is an important metal mineral, smelting, and processing site, and may have a certain degree of heavy metal pollution. To further clarify the heavy metal contamination of agricultural soils in this area, we collected 241 surface soil samples from agricultural land in Yingtan City, Jiangxi Province. We determined the contents of nine elements, including chromium (Cr), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd), lead (Pb), manganese (Mn), and mercury (Hg), and carried out their ecological risk evaluation based on the ground accumulation index method and the potential ecological risk evaluation method. Subsequently, the source analysis was further carried out by Spearman's correlation and PMF model. The results showed that the average concentrations of Cr, Ni, Cu, Zn, Cd, Pb, and Hg in agricultural soils in the study area were higher than the background values, respectively. The average content of Cd is higher than the national soil risk control value for agricultural land. The results of risk evaluation showed that there is a certain ecological risk of heavy metals in agricultural soils in the area, among which the potential ecological risk of Cd is higher. The results of PMF model analysis show that Hg is mainly released from the burning of fossil fuels or smelting of non-ferrous metals as a source. Cr is dominated by the over-application of chemical fertilizers and pesticides as the main source. Cd, Pb, and Zn are dominated by the smelting sources of lead and zinc mines. As, Cu, and Ni are influenced by stronger industrial activities and may be closely related to atmospheric deposition and irrigation water. Mn is dominated by soil-forming parent material sources. In Yingtan City, Jiangxi Province, the findings of this study provide a theoretical basis for reducing heavy metal pollution in agricultural soils, ensuring food security, strengthening the control of various industrial and mining enterprises, and improving heavy metal pollution in agricultural soils.