Pollution and health risk assessment of heavy metals in soils of Guizhou, China

Mining of minerals in Guizhou, China, where it is enriched with reserves, may lead to soil contamination with heavy metals. We assessed the risk of eight typical heavy metals in Guizhou soils by collecting province-wide data available in the literature and using the geo-accumulation index method, the ecological risk assessment method, and the USEPA health risk assessment model. The concentrations of eight heavy metals, except for Pb and Cr, were above the background levels. Soil heavy metal pollution evaluation results showed that As, Cu, Zn, Pb, Cr, Cd, and Ni reached the pollution levels, while Hg fell into the category of moderate contamination. As, Cu, Zn, Pb, Cr, and Ni posed low potential ecological risk, while Cd and Hg demonstrated a considerable or a very high potential ecological risk. Totally, the integrated potential ecological risk was ranked "very high" . Regarding to health risk, the non-carcinogenic risks caused by heavy metals were insigni?cant, but the carcinogenic risk caused by As was signi?cant. Consequently, there appeared serious soil contamination of Hg and As, with the latter also being the greatest potential risk to human health. Both Hg and As should stay at the highest priory for remediation efforts in Guizhou soils.