Groundwater chemistry and health risks associated with nitrate intake in Hailun, northeast China.

In order to quantify the hydrochemical characteristics of groundwater in Hailun, analyze the hydrochemical process, and evaluate its health risks associated with nitrate intake, 77 shallow groundwater samples were collected and analyzed. The results show that groundwater in the study area is weakly acidic and groundwater chemical type was dominated by HCO3-Ca, HCO3•Cl-Ca, HCO3-Ca•Na and HCO3•Cl-Ca•Na. Rock weathering and dissolution, ion exchange, and human activities are the main reasons affecting the chemical composition of shallow groundwater in Hailun. The weathering and dissolution process of silicate under weakly alkaline conditions is the source of Na. The dissolution of calcite, dolomite, and gypsum are the main form of water-rock interaction. Results of health risk assessment show that the HQ value for adult males, adult females, children, and infants were in range of 0-1.52, 0-1.75, 0-3.58 and 0-6.08, respectively, and with a mean value of 0.19, 0.22, 0.44, 0.75, respectively. The harm of NO3 pollution is in the order of infant > child > adult female > adult male. The results of this study made local governments pay attention to drinking water safety issues for local residents.