Health Risk Assessment of Carcinogenic and Non-carcingenic Substances in Underground Water from the Shuangcun Karst System of Central-Southern Shandong Province

Currently the majority of water quality assessment in China is based on comparison parameters of water with those of drinking water standards.However, to what extent the pollutants influence human health is less known.Herein, Shuangcun karst water samples in central-southern Shandong province were chosen to evaluate human health risk.Using the risk assessment model of USEPA, the risk induced by two carcinogenic substances, such as As, Cr(Ⅵ) and seven non-carcinogenic substances(Hg, F, CN^-, NO₂^--N, NH₄⁺-N, NO₃^--N, phenols) are evaluated.Results show that concentration of NO₃^--N and NO₂^--N in samples from several sites exceeds the limiting value of Hygienic Standard for Drinking Water(GB5749-2006).In terms of annual personal health risk caused by gene toxic substances through water drinking, Cr(Ⅵ) shows greater risk than As.In terms of risk caused by non-gene toxic substances, the induced risk has the sequence of NO₃^--N> F> NO₂^--N> Hg> CN^-> NH₄⁺-N> phenols.Moreover, the hazard of carcinogenic substances is much stronger than that of non-carcinogenic substances.Cr(Ⅵ) is the primary pollutant.For all the sampling sites, total risk values range from 5.0×10^-5 to 10.0×10^-5 a^-1, and the risk level is Ⅳ(fair).It means that underground water in the sampling area is harmful to human health to some extent.Therefore, it is worth more attention when the studied water serves as the drinking water source.