Partition pattern and environmental consequences of the widespread coalmines and host rocks on the water of selected regions, China

Abstract

The massive exploration and random dumping of coals in various regions of China create serious environmental and health problems because of the presence of toxic trace elements (TTEs), which possibly transfer to environment and cause serious health issues. This study was conducted to probe the environmental consequences of coalmines on the aquifer water and their association with health risks and the environment. For this purpose, 100 s of water samples was collected from the typical coalmine regions of Hancheng, Huanglong, Binxian, Handan, Langao, and Fusui and analyzed for various parameters. In Handan mining areas, Se, Mn, Fe, TDS, SO₄^2-, and total hardness were higher than the WHO standard, while in Hancheng, SO₄^2- was > 95%, Ca²⁺ 40-96%, and Mg²⁺ was 0-40%, which caused permanent hardness. In the Fusui and Huanglong areas, the SO₄^2- concentration was > 95%, Ca²⁺ 60-100%, and Mg²⁺ 20%, causing permanent hardness. In Binxian, HCO₃^- was 70-90%, Ca²⁺ 60-80%, and Cl^- and SO₄^2- were 20%, causing temporary hardness. In the Kashin-Beck disease (KBD) area, Se in the Middle Triassic was 0.3, Upper Triassic 0.23, and Quaternary 0.01, while fluoride (F) was 124.7, 141.6, and 159 in μg L^-1. The Handan water is included in rock-evaporation dominance (a mixed controlling mechanism), Hancheng, Binxian, Huanglong, and Langao water was included in rock dominance, while the Fusui water was included in rock-precipitation dominance. The average daily intake ((ADI) mg kg^-1 d^-1) of Ba, Cd, Co, Cr, Cu, Fe, Ti, Tl, Mo, Ni, Zn, Pb, Be, U, and Sr was comparably higher than No Observed Adverse Effect Level (NOAEL), which surely causes high health risk in selected regions. The elemental contaminants in the water were attributed to the geological environment, geochemical processes, ion exchanges, redox reactions, and dissolution of mineralized rock. For aquifer safety, coal mining, and other geological activities should be avoided to protect the water for future generations.

Keywords: China; Coalmines; Health risk; NOAEL; Permian.