Hydro-Geochemical Characteristics and Health Risk Evaluation of Nitrate in Groundwater

Groundwater is considered a major source of drinking water and its quality a basis for good population health. In order to identify groundwater hydro-chemical characteristics and pollution conditions in Songnen Plain, groundwater hydro-chemical characteristics and nitrate-nitrogen (NO3-N) spatial distribution characteristics and the health risks were analyzed. Results showed that groundwater hydro-chemical type was mainly HCO3-Ca, which was associated with the action of calcite and silicate mineral weathering dissolution. The over standards rate of NO3-N accounted for 50.8%, the coefficient of variation was 183.57% which was high spatial variability, the high-risk area accounted for 88.78% of the total study area, and the high-risk area covered the area with water quality of classes IV, V, and part of class III. The high-risk area is mainly distributed in the eastern high plains and in the central low plains, while the low-risk zone accounts for only 11.22% of the total area and is mainly distributed in the western alluvial plain with scattered distribution in other areas.