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To investigate the health risks of typical soil heavy metals to surrounding residents of industrial land in the urban-rural area of Liuquan Town, Xigu District, Lanzhou City, China. The contents of As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn were analyzed using an X-ray fluorescence spectrometer. Non-carcinogenic and carcinogenic risks of the heavy metals to children and adults were evaluated. Results showed higher soil Hg, Pb, and Zn contents in the study area than the corresponding background values of Gansu Province. The Hg pollution was the most serious, showing higher contents than the background water at 56.41% of the soil sampling sites. As, Cr, Cu, Ni, and Pb showed normal distributions, while Cd, Hg, and Zn exhibited skewed distributions. Hg and Cd showed the highest coefficients of variation of 0.966 and 0.548, respectively. Health risk evaluation results showed higher total non-carcinogenic risk (HI) and total carcinogenic risk (TCR) for children than those for adults by 5.411 and 2.156, respectively, indicating children are more susceptible to non-carcinogenic and carcinogenic risks. In addition, As, Cr, and Pb were the main contributors to the non-carcinogenic risk, while As and Cr were the main contributors to the carcinogenic risk. [ABSTRACT FROM AUTHOR]

Taiyuan Formation limestone groundwater is the main aquifer threatening the safety of exploration under deep mining in the Huaibei coalfield. Therefore, acknowledging the hydrochemical characteristics and constructing reverse hydrogeochemical modeling are crucial for predicting and preventing mine water hazards. In this study, the mathematical statistical analysis, Piper threeline diagram, Gibbs diagram, ion proportional relationship, Chlorine-Alkali index, and the reverse hydrogeochemical modeling were employed for determining the hydrochemical characteristics and the formation mechanism. The results revealed that the hydrochemical types of groundwater samples were SO4.Cl-Ca.Mg and HCO3.Cl-Na, respectively. The water-rock interactions were primarily influenced by the leaching and the cation exchange, with these processes being more intense in the eastern region. Through reverse hydrogeochemical modeling, the water-rock interactions in the process of groundwater runoff were quantitatively verified, viz. the calcite and the dolomite were saturated and precipitating, while the gypsum and the halite were unsaturated and still dissolving. Furthermore, the simulations of mass transfer in groundwater runoff indicated that the dissolution and the leaching of gypsum, dolomite and halite, positive ion exchange, the precipitation of calcite, and the dissolution of CO2 gas predominantly occurred along four simulated flow paths. These results offered a scientific foundation for the prevention and controlling of mine water hazards in deep mining contexts. [ABSTRACT FROM AUTHOR]