Geospatial Distribution and Potential Noncarcinogenic Health Risk Assessment of Nitrate Contaminated Groundwater in Southern India: A Case Study.

Groundwater nitrate pollution is a serious threat to human health in many regions of the world. The present study was performed to assess the nitrate contamination in groundwater in the region of Nirmal province, South India, where people purely depend on groundwater for drinking purposes. The associated human health risks for different age groups (male, female, and children) also were evaluated based on the United States Environmental Protection Agency model. Results indicate that nitrate concentration in groundwater is in the range of 0.8-130 mg/L with a mean of 36.51 mg/L. Furthermore, 26.47% of groundwater samples exceeded the WHO drinking water guidelines for NO3- in the study region. The contribution of oral ingestion is very higher than the dermal contact in the total hazard quotient or noncarcinogenic health risk. The total hazard quotient values ranged from 0.02 to 3.13 for adult males, 0.02 to 3.70 for adult females, and 0.03 to 4.32 for children. The health risk assessment highlights that children are more exposed to the noncarcinogenic health risks of nitrate than adult females and males in the study region. Therefore, specific groundwater quality measures should be formulated to address the health risk problems for children in the study region.