Fluoride contamination in groundwater is above-permissible levels of the mineral across states of Rajasthan, Telangana, western Andhra Pradesh and eastern Karnataka.
It has also prevailed in parts of Haryana, Gujarat, Madhya Pradesh, Tamil Nadu, Uttar Pradesh, Jharkhand, Bihar and Chhattisgarh.
Excess fluoride increases the risks of disease conditions like skeletal fluorosis, accelerates the rate of dental decay.
The nationally permissible limit of Fluoride is 1.50 milligrams/litre.
Contamination over 1.50mg/litre is deemed unfit for drinking purposes.
The average concentration of fluoride in groundwater was higher in dry, western Indian regions.
Rajasthan topped in the charts and the post-monsoon concentration of fluorine was found to be above normal in Karnataka, Tamil Nadu and Jharkhand.