Fluoride in drinking water:
- Fluorine, a highly reactive gas seldom occur in nature in elemental form. It has very high affinity to combine with other elements or molecules and form fluorides.
- In nature, the most common fluoride containing compounds are 3 · calcium fluorite (Fluorspar; CaF2) · Cryolite (Sodium Aluminium Fluoride; Na3AIF6) and · Calcium phosphate (Apatite) complex.
- The geological crust in India is very rich in fluoride bearing minerals. Though the country is mineral rich, it has its own problems too.
- Fluoride is known to leach out and contaminate the underground aquifers.
- In India a large population in villages depend upon ground water drawn through hand-pumps, tube wells (energized) and open wells, for consumption · consuming untreated groundwater led to excess fluoride entry to the body.
- The urban population too, due to shortage of treated water, are dependent on ground water to a large extend.
- Groundwater used maximally for irrigation for agricultural purposes, the crops are also contaminated with high fluoride.
- India has a major public health problem as a result of ingestion of excess fluoride through drinking water and food (agricultural crops) besides processed food.