An integrated method for environmental risk assessment of potential toxic elements leaching from antimony mine tailings

Large volumes of abandoned open-pit antimony tailings release potentially toxic elements (PTEs) through weathering and leaching, impacting the surrounding ecosystem and human health. This study assessed PTEs pollution and risks in open-pit antimony tailings in Southwest China, focusing on Sb, As, Zn, Ni, Cd, Cu, Cr, and Pb. The comprehensive pollution risk ranking for PTEs was: Sb > As > Zn = Cd > Ni > Pb > Cr > Cu. Static leaching experiments showed that As, Cd, Pb, and Cu exhibited higher mobility under acidic, high-oxidation, and high-salinity conditions, while Sb release was more sensitive to particle size variation. Principal component analysis (PCA) of leachate water quality indicated that minimizing tailings exposure to water and air and reducing the generation of 1.18 mm-4.75 mm tailings particles are essential to effectively limit PTEs leaching. Monte Carlo simulations revealed that PTEs in tailings pose both non-carcinogenic and carcinogenic health risks to adults and children, with children at higher risk. As and Sb were associated with a higher non-carcinogenic risk, while As and Ni posed potential carcinogenic risks. Notably, in this study, As posed the highest non-carcinogenic and carcinogenic risk to children, making it a key element of concern.