Environmental and human health risks from cadmium exposure near an active lead-zinc mine and a copper smelter, China

Abstract

Cadmium (Cd) contamination from mining and smelting operations has led to growing environmental health concerns. In this study, soil, surface water, drinking water, rice, vegetables, and biomarkers (hair and urine) were collected from local residents near an active lead-zinc mine and a copper smelter. The aim was to determine how nonferrous metal mining and smelting activities have affected the health of local residents. It was found that the Cd concentrations in most soil and rice samples exceeded the national tolerance limits of China. Dietary intakes of rice and vegetables were the two major pathways of Cd exposure to local residents, accounting for >97% of the total probable daily intake. The excessive daily intake of Cd resulted in potential non-carcinogenic risks to the local residents, especially to children living around the two areas. The mean hair and urine Cd concentrations were 0.098 ± 0.10 mg kg−1 and 5.7 ± 3.1 μg L−1 in the mining area, and 0.30 ± 0.21 mg kg−1 and 5.5 ± 3.5 μg L−1 in the smelting area, respectively. A significantly positive correlation between hair Cd concentrations and the hazard quotient (HQ) for rice ingestion indicated that rice contamination had the most critical adverse effect on local residents. Due to the high levels of environmental Cd contamination, residents of the smelting area had a much higher Cd exposure than residents of the mining area. The results suggested that nonferrous mining and smelting should not coexist with agricultural activities. Effective contamination mitigation strategies and environmental remediation should be formulated and implemented to improve the health of local residents.