Over 36% of Indian districts or 263 out of the total 722 districts in the country now have groundwater concentration of fluoride that is higher than the permissible 1.5 mg/L. The number of districts with high concentration of fluoride in water (1.5 mg/L) has increased from 207 in 2017 to 263 in 2023. These are some of the findings of the National Ground Water report released recently. One of the findings in the report is about the surge in fluoride concentration in groundwater that is linked to overexploitation.
The Bureau of Indian Standards recommends an upper desirable limit of 1.0 mg/L of fluoride in drinking water, which can be extended to 1.5 mg/L in case no alternative source of water is available. Higher concentration of fluoride in drinking water is linked to a host of debilitating diseases like waterborne fluorosis, dental and skeletal fluorosis. It can cause staining of tooth enamel, while higher concentrations (5.0 to 10 mg/L) can lead to pathological changes like stiffness of the spine and difficulty in natural movement.