Health Risk Assessment of Nitrate Contamination in Groundwater: A Case Study of an Agricultural Area in Northeast China

High levels of nitrates in groundwater pose a risk to human health. In this study, we selected areas with typical agricultural nitrate pollution in northeast China as study sites. We then collected groundwater samples for nitrate nitrogen content analysis using the Four Step method developed by the United State Environmental Protection Agency (USEPA) in conjunction with the non-carcinogens health risk model (R = CDI/RfD) to determine the health risk associated with nitrate pollution of groundwater. The reference value of nitrates in drinking water was set at 10 mg/L (measured as nitrogen) and the intake reference dose of nitrate was set at 1.6 mgaEuro cent kg(-1)aEuro cent d(-1) based on the EPA's IRIS(Integrated Risk Information System). The water intake reference values were set at 2.3 L/d and 1.5 L/d based on the EPA values and actual values observed in the study area. The average exposure time was the ED (exposure duration) x 365d/a. Weights refer to the 2002 national urban and rural average weight of residents of different genders and different ages. Health hazard index calculation was based on the above information, and the index less than 1 is acceptable (U.S. EPA's Risk Assessment Guide). Health risk assessment maps were then drawn by Arcgis software. The results indicated that agricultural sewage irrigation areas in the study area showed strong health risks, but that those of the city were relatively small. Moreover, the results indicated that children's health risks are greater than those of adults.