Source analysis and health risk assessment of groundwater pollution based on multivariate statistical techniques in...

In this study, 63 groundwater samples were collected in the Kashgar Delta Area in Xinjiang in 2016, and then, the samples were tested and the test results were analyzed. Multivariate statistical techniques were used to determine the sources of pollution, and the USEPA (United States Environmental Protection Agency) model was used to assess the long-term health risk of groundwater to adults and children in the study area. The concentrations of groundwater chemical Na⁺, Cl^-, SO₄^2-, NH₄⁺-N, TDS, F^-, I^-, As, Fe, Mn, Pb, Hg, pH, TH, and COD_Mn, which exceed the permissible level in the study based on groundwater quality index and possibly pose a potential threat to the health of the residents in the area, which are mainly influenced by geological conditions. The source of the pollutants is the dissolution of minerals in the aquifer medium, which is greatly affected by the high-salinity groundwater environment, pH conditions, redox conditions, and evaporation and concentration effect. The values of the noncarcinogenic health risk index HQ_n follow the descending order of Cl^- > F^- > As > Fe > Mn > Pb > Hg > NH₄⁺-N; There are eight nonarcinogens and one carcinogen in groundwater of which Cl^- is the dominant noncarcinogenic factor, while As is the main carcinogenic pollutant in the study area. The health risk ratio results show that Cl^- and As are the main pollutants that pose the greatest threat to both adults' and children's health, and they should be considered as the primary indicators for health risk management and control.