Hydrogeological properties, sources provenance, and health risk exposure of fluoride in the groundwater of Batkhela, Pakistan

Abstract

This study aimed to determine the fluoride (F − ) concentration, fate distribution, source provenance, geochemistry, and health risk exposure through oral ingestion of groundwater. Therefore, 60 groundwater samples were collected from five areas of sub-district Batkhela viz. Batkhela colony, Pirkhel, Selay Patty, Thana, and, Totai. The range concentrations of F − in the groundwater samples collected from the aforementioned areas were 0.50–2.30, 0.90–2.30, 0.50–2.40, 0.30–1.50, and 1.20–2.40 mg/L, and mean were 1.60, 1.50, 1.60, 0.90, and 1.70 mg/L, respectively. The results of fluoride showed that 28.5% of the groundwater samples exceeded the world health organization (WHO) guideline value of 1.5 mg/L. The chemical facies identified three types of groundwater such as CaHCO 3 (55%), NaHCO 3 (32%), and NaCl (13%). Moreover, alkaline pH high HCO 3 − and Na + concentration, while depleted Ca + + and Mg + + concentration promote F − dissolution in the groundwater aquifer. The principal component analysis and Gibbs plot define that weathering and dissolution of granite rock minerals play a key role in the control of groundwater chemistry. Additionally, the ion exchange process also plays an important role in releasing F − in the groundwater aquifer. Whereas cluster analysis identified three clusters: C1 was less polluted, C2 was moderately polluted, and C3 was a severely polluted cluster and their percentage contribution was 20%, 58%, and 22%, respectively. Health risk assessment of F − for non-cancer risk in males, females, and children shows high health risk exceeded the recommended value of 0.6 for the community. Therefore, the groundwater sources of the study area are unfit for drinking, and domestic purposes. • 28.3% water samples of Batkhela exceeded the WHO guideline values of 1.5 mg/L of F − . • Health risk of F − shows community fluorosis for both adults and children. • Base ion exchange and weathering processes are responsible for F − contamination. • PCA results shows that groundwater contamination was due to known mineral prospects. • CaHCO 3 (55%), NaHCO 3 (32%), and NaCl (13%) were the major water type.