“…It is the main inorganic toxicant of fluorine, predominantly promoted by alkaline pH, high concentrations of sodium cations (Na + ) and bicarbonate (HCO 3 − ), and low concentrations of calcium ions (Ca ++ ) (Guo et al, 2007;Rafique et al, 2009). Fluoride enrichment mostly occurs in groundwater, soil, rocks, food, air, flora, fauna, and the human body (Rakshit, 2004;Raju et al, 2012;Varol et al, 2013;Raju et al, 2014;Singh et al, 2015;Xiao et al, 2015aXiao et al, , 2015bPatel et al, 2016). Groundwater is the principal source of F − for human ingestion, potentially recognized and controlled by the regional chemistry of the host rock, hydrogeology, anthropogenic activities, and climatic factors (Frengstad et al, 2001;Saxena and Ahmed, 2003;Edmunds and Smedley, 2005;Chae et al, 2007;Khaliq et al, 2007;Rafique et al, 2009;Singh et al, 2015).…”