The nitrate of groundwater in the Gimpo agricultural area, South Korea, was characterized by means of nitrate concentration, nitrogen-isotope analysis, and the risk assessment of nitrogen. The groundwaters belonging to Ca-(Cl + NO 3) and Na-(Cl + NO 3) types displayed a higher average NO 3 - concentration (79.4 mg/L), exceeding the Korean drinking water standard (<44.3 mg/L NO 3 -). The relationship between δ 18O-NO 3 - values and δ 15N-NO 3 - values revealed that nearly all groundwater samples with δ 15N-NO 3 - of +7.57 to +13.5‰ were affected by nitrate from manure/sewage as well as microbial nitrification and negligible denitrification. The risk assessment of nitrate for groundwater in the study area was carried out using the risk-based corrective action model since it was recognized that there is a necessity of a quantitative assessment of health hazard, as well as a simple estimation of nitrate concentration. All the groundwaters of higher nitrate concentration than the Korean drinking water standard (<44.3 mg/L NO 3 -) belonged to the domain of the hazard index <1, indicating no health hazard by nitrate in groundwater in the study area. Further, the human exposure to the nitrate-contaminated soil was below the critical limit of non-carcinogenic risk.
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Acknowledgments This work was financially supported by the Korea Ministry of Environment as ‘‘The GAIA Project’’.
All Science Journal Classification (ASJC) codes
- Global and Planetary Change
- Environmental Chemistry
- Water Science and Technology
- Soil Science
- Earth-Surface Processes