Soil Heavy Metal Pollution and Health Risk Assessment in a Tin Mining Area

To evaluate the impact of mining activities on heavy metal pollution and health risks in the soil of a mining area, this paper systematically studied a tin mining area with a relatively simple geological background using the ground accumulation index method and Monte Carlo health risk assessment method. The results showed that: (1) The average heavy metal content in the soil of the study area was ranked in descending order: As>Zn>Pb>Cu>Ni>Cr>Cd>Hg. Only the average value of As exceeded the screening value (GB 15618—2018), while the average values of the other seven heavy metal elements did not exceed the standard; (2) Among them, the relatively high concentration areas of Cu, Pb, Zn, Cd, As, and Cr are located near the mining area and altered (mineralized) granite; (3) The land accumulation index method reveals that the pollution of As in the soil of the study area is relatively prominent, with higher levels of Pb and Cd pollution, lower levels of Cu, Zn, and Ni pollution, and almost no pollution of Cr and Hg; (4) Correlation analysis and principal component analysis indicate that the sources of heavy metal elements in soil mainly include natural sources and mining sources; (5) The health risk assessment results of Monte Carlo simulation indicate that children are more susceptible to the effects of heavy metal exposure, with As and Ni posing a higher risk of cancer for both children and adults; Sensitivity analysis further emphasizes the significant impact of As and Ni on health risks in different populations. In summary, there are slight heavy metal pollution and risk in a certain tin mining area, which are mainly controlled by the weathering of altered granite, safe and controllable.