The rapid development of the global chemical industry has led to widespread groundwater contamination, with frequent pollution incidents posing severe threats to water safety. However, there has been insufficient assessment of the health risks posed by chlorinated hydrocarbon contamination in groundwater around chemical industrial parks. This study evaluates the chlorinated hydrocarbon contamination in groundwater at a chemical park and conducts a multi-pathway health risk assessment, identifying the key risk pollutants. In addition, sensitivity analysis of the primary exposure pathways was performed using the Monte Carlo method. The results indicate severe exceedance of pollutant concentrations with widespread diffusion. Carcinogenic risks were mainly driven by vinyl chloride, whose oral cancer slope factor was significantly higher than that of other substances, while non-carcinogenic risks were dominated by trichloro-ethylene, which had the lowest reference dose. Both carcinogenic and non-carcinogenic risks through the drinking water pathway accounted for approximately 90% of the total risk, whereas the risk contribution from dermal contact was negligible. Although boiling water can partially reduce the risks, its effect on high-concentration pollutants is limited. Additionally, sensitivity analysis showed that pollutant concentration was the primary influencing factor for risk values, followed by exposure duration. The findings of this study provide a scientific basis for effectively formulating pollution control measures and ensuring the drinking water safety of nearby residents.

Karst groundwater is the main water source for domestic, industrial, and agricultural needs in Xingtai City, North China. The objective of this study was to comprehensively access changes in the hydrochemical characteristics and evolution of karst groundwater in response to rapid urbanization. Water samples from the late 2010s and the 1970s were compared utilizing statistical analysis, hydrochemical diagrams, and inverse simulation technology. The total dissolved solids (TDS), total hardness (TH), NO₃⁻, and Fe contents were significantly higher in the more recently obtained karst groundwater samples. Further, the dominance of HCO₃-Ca-type water decreased, with new types emerging, relative to 1970s karst groundwater. Abnormal TDS, TH, SO₄²⁻, NO₃⁻, and Cl⁻ concentrations can be attributed to sewage discharge and fertilizer. Two groundwater discharge areas around the center of Xingtai City and Yangfan Town in the south of the study area were the most significantly affected by human activities. However, inverse modeling indicated that the dissolution of gypsum and halite, as well as cation-exchange processes, occurred in the groundwater paths during both periods. Recent increases in ion concentrations of karst groundwater in the study area have caused carbonate minerals to dissolve, resulting in a further increase of ion concentrations. The hydrochemical response and evolution of karst groundwater requires further study.

Groundwater contamination in industrial parks often involves overlapping inputs of nitrogen, chlorinated solvents, and dissolved salts, making source identification difficult. In this study, 45 shallow groundwater samples from a typical industrial park on the northern margin of the Hohhot Basin were investigated using hydrochemical analysis, PMF, and nitrate dual isotopes coupled with MixSIAR. The results showed pronounced salinity enrichment, high mineralization, elevated ammonium, and chlorinated hydrocarbon contamination. NH₄⁺ exceeded the Chinese groundwater standard in 77.78% of samples, whereas vinyl chloride exceeded the WHO guideline value in all samples. Hydrochemical analysis indicated that groundwater chemistry still retained a water-rock interaction background, but had been significantly overprinted by anthropogenic inputs. PMF resolved six factors and showed that groundwater pollution was mainly controlled by high mineralization, high-ammonium wastewater input, and dissolved inorganic salt enrichment, whereas chlorinated-solvent industrial pollution had strong diagnostic significance. MixSIAR identified industrial wastewater as the largest nitrate contributor under both prior settings, followed by fertilizer-derived nitrification, whereas mountain-front soil background contributed comparatively less. These results indicate that the combined PMF-MixSIAR framework is effective for identifying mixed groundwater contamination in industrial parks.