Sources, flux, and potential risks of heavy metals in soils around the smelting and mining area

Field sampling and flux monitoring were jointly applied to evaluate how the intensive smelting and mining affected the heavy metal (HM in short) transfer to soils in Shuikoushan, China. Mining and smelting resulted in both the increase of HMs contents and their environmental availability. The closer to the smelting and mining center within the distance of 8.0 km, the more obvious HMs accumulation. Smelting and mining also led to the soil acidification. Soil parent materials, agricultural activities, mining-related activities, and smelting activities were the main sources of HMs in soil. Mining and smelting were the main sources of Cd (86.7 %), As (46.5 %), Cu (56.4 %), Pb (88.8 %), and Zn (60.8 %) in surface soil. Soil parent materials and historical mining contributed ∼70 % of the HMs in deep soils. Agricultural use of arsenic-containing fertilizer was also an important source of soil arsenic. Atmospheric deposition impacted by smelting and mining had become the main route of HM input to soil. 30.8 % of the local adults could suffer from the carcinogenic risk at an unacceptable level (10^-4) due to the long-term exposure of soil HMs. Cd and As were the two main risk factors. Results obtained indicated that smelting and mining could constant increase the accumulation and environmental availabilities of HMs in soils under the current regulation policies. Further studies are necessary to quantify these negative impacts and as well to develop the effective countermeasures to reduce the soil HM content.