Potential toxic heavy metals in village topsoil of antimony mining area: Pollution and distribution, environmental safety----A case study of Qilijiang village in xikuangshan mining area, central Hunan Province, China

Abstract

Potential toxic heavy metal elements in the topsoil of villages in antimony mining areas pose a serious threat to residents' health, and scientific analysis of potential toxic heavy metal element contamination in the topsoil of villages in antimony mining areas and environmental safety is especially important for residents' health and the high quality of sustainable development in the mining areas. In this study, we chose Qilijiang Village in the Lengshuijiang Tin Mine in Hunan Province and used field sampling and indoor experiments to investigate the toxic heavy metal pollution and environmental safety of the topsoil using key technologies such as geomatics mathematical analysis, analysis of variance (ANOVA), GIS, and environmental risk assessment modeling.The average contents of potential Pb, Cr, As, Cd, and Sb in the topsoil of the residential area exceeded the standard values by 1.12, 1.00, 15.82, 13.37, and 38.87 times, respectively; the degree of contamination risk was As > Sb > Cr > Pb > Cd in the order of As > Sb > Cr > Pb > Cd; and the high-loading elements were As and Sb with a high degree of homology. The results of spatial and principal component analysis revealed that the potential Pb, Cr, As, Cd, and Sb in the surface soil of the residential area were influenced by discrete sources such as mining, processing, and other industrial and mining activities, as well as dust deposition and residents' domestic drainage water (As and Sb); the natural geological backdrop and the metal products industry (Cr); lead-acid batteries, industrial activities, and gasoline additives (Pb); residents of the residential area, green space, and resident gardens; fertilizer application; and pesticide use (Cd). According to the results of the environmental safety analysis, Sb, As, and Cd are in the heavy pollution category, while Cr and Pb are in the low pollution category, and the ecological danger of metals is Cd (401.22) > Sb (388.70) > As (158.16) > Pb (5.58) > Cr (2.00).Cd and Sb have reached a very high degree of ecological risk; As is at a higher risk level; and Pb and Cr are at a lower or no risk level. Except for As and Sb (HI value > 1), the non-carcinogenic risk of village topsoil was insignificant, and Pb, Sb, and As in topsoil exhibited carcinogenic risk, with As exceeding the permissible level, and the carcinogenic risk of As in Qilijiang village was more serious than that of Sb. The study's findings are critical for implementing preventive steps to protect the ecosystem and assure long-term growth in the area.