Eco-Environmental, Human Health Risk Assessment of Soils and Crops Heavy Metals in the Typical Black-Rock Series Area in the Northern Daba Mountains, China.

Heavy metals (HMs) pollution in the black-rock series has attracted much attention, some HMs in soils and crops exceed the safety limits. This study investigated the concentrations of heavy metals in the soil, conducting eco-environmental and human health risk assessment of heavy metals in the typical black-rock series area in the northern Daba Mountains, China. Results showed that the concentrations of As, Cd, Cr, Cu, Hg, Ni, and Zn were higher in the study area than the Chongqing soil background values. The average Cd concentration (2.40 mg/kg) was 24.7 times that of the Chinese background value. The geo-accumulation index (Igeo) showed that the soil was "heavily contaminated" with Cd, and uncontaminated with Pb. The potential ecological risk of heavy metals in the soil were mainly from Cd and Hg. Through a human health risk assessment based on the main crops from the study area, the exposure risk index of each heavy metal was less than 1, with Cd being the largest (0.54). However, the total index was more than 1 (1.58), indicating human health risk in the study area. Meanwhile, the exposure risk index for the potato crop was the highest among the four crops, reaching 0.69. Therefore, adjusting the planting structure in the study area, avoiding cultivating leafy vegetables with strong heavy metal absorption capacities, and reducing the potato crop sizes are all suggested measures. [ABSTRACT FROM AUTHOR]