Assessment of Heavy Metals and Their Relationship With Soil Texture in Cultivated Soil in Dong Thap, Vietnam

Abstract

The contamination of heavy metals in cultivated soils has become a critical concern worldwide. This study examined the concentrations, pollution sources, environmental, and ecological risks, and both noncarcinogenic and carcinogenic health risks of major heavy metals in soils in Dong Thap province, Vietnam. The average concentrations of As, Pb, Cu, Zn, and Cd measured 4.80, 13.94, 24.49, 94.67, and 0.06 mg·kg⁻¹ dry soil, respectively. Concentrations of these metals did not differ significantly across soils cultivated with different crops and plants in most locations. Using mathematical models, we assessed the ecological risk index (RI) and found values ranging from 15.36 to 57.36, indicating that local soils varied from non-polluted to extremely polluted in terms of ecological risk. The noncarcinogenic risk assessment showed that all heavy metals posed no threat of noncarcinogenic effects. In contrast, some monitoring locations contributed significantly to carcinogenic risk for children, while other locations presented tolerable carcinogenic risks for both children and adults. Pearson correlation analysis revealed weak correlations between heavy metals and soil texture components such as sand, silt, and clay. Overall, these findings offer new insights into the long-term presence of heavy metals in soil, their sources, and their potential impacts on ecosystems, while also providing a theoretical foundation for soil pollution management.