Fluoride as a global groundwater contaminant

Fluoride is essential for the human body and a global groundwater contaminant (the recommended WHO limit is 1.5 mg/L). The mobilization and genesis of fluoride depend on fluoride-bearing rocks (e.g., fluorite, fluor-apatite, biotite, etc.) that are a part of the natural geogenic process, which later contaminate the groundwater. More specifically, the dissolution process (via infiltration), lateral water flow, ion exchange, climatic factors, and chemical weathering of “rocks and minerals” are highly responsible for the release of elevated concentrations of fluoride in groundwater. The intake of fluoride-contaminated groundwater and anthropogenically produced daily usable products (e.g., dental products, foods, etc.) causes physiological and metabolic disturbances in animals and humans. However, this fluoride can be removed effectively from water by technology-enhanced processes (e.g., reverse osmosis, nano-filtration, coagulation, adsorption, electrochemical, membrane distillation, ion exchange, and precipitation). This, in turn, means that climate-dependent contamination, mobilization mechanism, and bioaccumulation will be essential for selecting efficient, cost-effective green technologies. Adequate information should be provided to overcome people’s wrong perceptions concerning fluoride-related issues, especially in lower socioeconomic groups. Policy interventions are required to improve the quality of life in the developing world, where there is a lack of awareness about health issues. Extensive research in this field can identify fluoride “hot spots” (through regular monitoring) and removal technique(s) utilizing public-private sector collaboration.