Health Risk Assessment of Nitrate Pollution in Shallow Groundwater: A Case Study in China

High concentrations of nitrate in groundwater pose a threat to human health. To quantify groundwater nitrate pollution in China's Lianhuashan District and evaluate its human health risks, 73 groundwater samples were collected and analyzed. Results showed that the spatial distribution of groundwater chemical components was varied and concentrations were in the order of TDS>HCO3>Ca> Cl>SO4> Na>Mg>NO3>K>NH4 >NO2 center dot NO3 concentrations ranged from 0.02-340.49 mg/L and averaged 70.38 mg/L. Over 28.76% of samples exceeded the QSCB Class III threshold (20 mg/L N). Principal component analysis determined that NO3 contamination was primarily attributed to the excessive use of fertilizers in agriculture. A human health risk assessment model was used to assess the potential health risks of groundwater NO3 via drinking water and skin contact pathways. Approximately 94% of adults, 86% of children, and 66% of infants had acceptable health risks. NO3 exposure risk in the towns of Quanyan and Quannongshan were the highest, while urban areas tended to have lower exposures. The health risks to residents, especially minors and infants, were concerning.