Mapping mining-affected water pollution in China: status, patterns, risks, and implications

Abstract. Mining-affected water pollution poses a serious threat to human health and economic prosperity globally. The human toxicity and ecosystem impacts induced by mining activities have achieved considerable public, scientific, and regulatory attention. In this study, a comprehensive database of 8433 water samples from 211 coal mines and 87 metal mines in China was established to reveal the national status and spatial heterogeneity of mining-affected water pollution, human health risks, and their potential multifaceted challenges. The results show that the concentrations of sulfate, Fe, Mn, Al, and several heavy metals (HMs) in the mining-affected water of metal mines are generally higher than those of coal mines, especially in acid water (pH <6.5). In terms of spatial distribution, the gridded data demonstrate that the southern regions in China, especially Guizhou, Guangdong, Fujian, Jiangxi, Hunan, and Guangxi provinces/autonomous regions, are the hotspots of mining-affected water pollution (i.e., low pH, high sulfate, Fe, Mn, and heavy metals). The risk assessment reveals that the unacceptable carcinogenic risks caused by poor-quality surface water and groundwater are observed in 51.52 % (for adults) and 29.29 % (for children) of the mining areas. Moreover, severe non-carcinogenic risks are also identified in 68.07 % and 80.67 % of mining areas for adults and children, respectively. Overall, the acid and metal-rich water exhibits a widespread and detrimental impact in China, especially in the southern regions, posing significant risks to planetary health by degrading surface water and groundwater quality, destroying biodiversity, and threatening human well-being. This study provides a thorough set of scientific data on surface water and groundwater quality in mining areas to guide policymakers in designing differentiated management strategies for the sustainable development of coal and metal mines.