Groundwater quality and the potentiality in health risk assessment in Zhengzhou, China

Groundwater quality and suitability for drinking purposes in Zhengzhou City were investigated. A total of 30 water samples from 15 major monitoring wells were collected in January (dry season) and July (wet season), 2009. Seven common physicochemical (pH, permanganate index, ammonia, chloride, sulfate, hardness and the total dissolved solids) and 11 toxicological parameters (fluorine, nitrate, Zn, Fe, Mn, Cu, Cd, Pb, Se, Cr (VI) and As) were analyzed. Human health risk assessment for pollutants and water quality index for drinking purposes were also evaluated. The results showed that 6.7% of groundwater samples were considered as permissible for drinking and others as desirable; concentrations of chromium (VI) at site 14 and 15 were lower than the risk-based concentration associated non-carcinogenic effects (0.11 mg l−1), while higher than the standard associated carcinogenic effects (4.5E-5 mg l−1). The carcinogenic risk was 3.75E-6 at site 14 and 4.55E-6 at site 15, which indicated that the risks at bot...