Groundwater chemistry, distribution and potential health risk appraisal of nitrate enriched groundwater: A case study from the semi-urban region of South India.

In recent years, an elevated concentration of nitrate in groundwater has been a growing problem on a global scale. It directly shows the adverse effects on human health via various intake pathways. Herein, the aim of the present study was to evaluate the nitrate concentration in groundwater and its associated human health risk in various age groups (females, males and children) in the investigated region. For this purposes, thirty groundwater samples were collected and analyzed physico-chemical parameters including nitrate concentration. The results showed that, the concentration of nitrate ranges from 14 to 82 mg/L and about 43.3% of these groundwater samples beyond the safe level of 45 mg/L according to Indian guidelines. The higher nitrate contamination is observed in the vicinity of Sarvepalli and Timmapur villages where groundwater chemistry is majorly influenced by anthropogenic sources. Health risks were assessed through oral/ingestion and dermal contact exposure routes for females, males and children population in the study region. Oral exposure was much higher than dermal contacts. For the non-carcinogenic risk, the HI values of groundwater in the investigated region varied from 0.313 to 1.976 (mean of 0.941) for males, 0.370 to 2.336 (mean of 1.112) for females and 0.443 to 2.694 (mean of 1.314) for children. The health risk assessment for nitrate divulged that 60%, 57% and 50% of groundwater samples pose a non-carcinogenic health risk for children, females and males, respectively.