Evaluation of groundwater contamination for fluoride and nitrate in semi-arid region of Nirmal Province, South India: A special emphasis on human health risk assessment (HHRA)

The main aim of this study was to assess the groundwater quality and human health risks of fluoride and nitrate contamination in Nirmal Province, South India, where groundwater is the primary source for drinking water. Hazard quotient (HQ) and total hazard index (THI) were calculated to estimate the non-carcinogenic risk to men, women, and children using the most substantial method recommended by United States Environmental Protection Agency (USEPA). The results of the study reveal that 26% and 20.59% of groundwater samples have significantly high nitrate and fluoride concentrations, exceeding the maximum permissible limits set by Bureau of Indian Standards (45 mg/L and 1.5 mg/L, respectively). Therefore, ingestion of high fluoride and nitrate water could be the chief reason for health risk in the study region. The total non-carcinogenic health risks for men, women, and children ranged from 2.95E-01 to 4.07E+00, 3.49E-01 to 4.80E+00, and 3.99E-01 to 5.50E+00, respectively. Moreover, 67.65%, 79.41%, and 82.35% of the total collected groundwater samples exceeded the permissible limit for acceptable total health index (THI = 1) for men, women, and children, respectively. Therefore, the health risk assessment suggests that children face higher health risk than men and women in the study region.