Appraisal of hydrochemistry and non-carcinogenic risk assessment for the distribution of Fluoride and Nitrate in a semi-arid region

Abstract

Assessment of hydrochemistry, and its impact on human health via ingestion and dermal contact of Fluoride (F⁻), and Nitrite (NO₃⁻) concentrated groundwater was assessed via ingestion and dermal contact pathways. Sixty-one groundwater samples from a Dilwarpur Mandal, Nirmal district, Telangana State, India were collected and analyzed major ion chemistry for pre and post-rainy seasons from the semi-arid region. The concentration of F⁻ ranged from 0.24–3.28, and 0.08–1.52 mg/l with mean of 1.01, and 0.65 mg/l, around 48%, and 26% of samples exceeded the permissible limits (> 1 mg/l), and NO₃⁻ concentration ranges from 3–136, and 6 -132 mg/l with mean of 36 mg/l, and around 34% and 45% of samples exceeded the permissible limits (> 45 mg/l) for both the seasons. Elevated F⁻, and NO₃⁻ concentration due to the dissolution of fluoride-bearing minerals, and excessive use of nitrate fertilizers. Water Quality Index (WQI) ranges from 28–133, and 29–88 for both seasons. Piper plot suggests that CaHCO₃ type water with 56% and 51%; Mixed CaMgCl type water with 41% and 49% and Mixed CaNaHCO₃ type water with 3% each for both seasons. Gibbs plot suggests that most of the samples are rock dominant type and suggests that the water-rock interaction during the process of percolation water with high evaporation conditions. Principal component Analyses (PCA) suggest that the same factors contribute to an increase in F⁻ and NO₃⁻ concentrations in groundwater. Hazard quotient (HQ) via ingestion (HQ_ING) and dermal contact (HQ_DER) of F⁻ and NO₃⁻ experiences higher values than the threshold limit of 1.0 for various age groups, affecting human health due to non-carcinogenic effect, and immediately requires a suitable effective measure should be implemented in the area to avoid further health hazard impact on the existing society and for an upcoming generation.