Characteristics of heavy metal pollution in mine water inrush and environmental risk assessments

Abstract

Abstract The acid mine water inrush resulting from coal mining activities poses a threat to the regional groundwater, leading to heavy metal pollution that can adversely impact the ecological environment and human health. In this study, several mines in the Guangyuan area were selected as research subjects to determine the concentrations of eight heavy metals (Cr, Fe, Mn, Hg, As, Zn, Pb, Cd) present in the mine water inrush. Ecological risks and human health risks were evaluated using species-sensitive distribution curves and health risk assessment models. The results showed that Fe had the largest excess rate and was the main substance causing ecological risks. The total health risk in the study area was high, mainly derived from the carcinogenic metal elements Cr, Cd and As, and the carcinogenic risk was higher than the maximum risk limit of 10-4, and the total non-carcinogenic risk was less than the maximum acceptable health risk limit 1, indicating that mine water inrush had a lower non-carcinogenic health risk, among which Fe had the largest non-carcinogenic risk and Cr6+ had the largest carcinogenic risk, which should be paid attention to in subsequent treatment and repair.