Non-carcinogenic Health Risk Assessment of Fluoride and Nitrate of Groundwater-A Case Study of the Central Dry Zone of Chikkanayakanahalli Taluk, Tumkur District, Karnataka

Forty-two groundwater samples were randomly collected from Chikkanayakanahalli taluk during the pre-monsoon season of 2022 and were analysed for Fluoride and Nitrate levels using APHA standard methods. USEPA method was employed to assess the non-carcinogenic health hazards associated with exposure to NO3- and F- from drinking water consumption by computing estimated daily intake (EDI), hazard quotient (HQ) and total hazard index (THI). HQ(nitrate) > 1 through the ingestion pathway was observed in 14.28 and 4.76 % of the groundwater samples, respectively, for children and Teenagers, while HQ(fluoride) > 1 for children was reported in 16.66% of the groundwater samples. Higher mean values of HQ(Fluoride) over HQ(Nitrate) supported added contribution of fluoride in groundwater of the study area in the non-carcinogenic human health risk over nitrate among different age groups of the local population. Overall, the average THI values were 0.205, 1.452, 1.025 and 0.821, respectively, for Infants, children, Teenagers, and Adults, and their trend was in the order: children > Teenagers > Adults > Infants. It was found that 90.5%, 54.8%, and 14.3% of the samples progressed beyond the standard limit (THI = 1) for children, Teenagers, and adults, respectively, illustrating that children are more prone to non-carcinogenic risks than other age groups. Further, NHHR of F- and NO3- in groundwater was higher for children, attributed to their lower body weight over teenagers and adults, besides average water consumption rates.