Chennai: Tamil Nadu is one of the 19 states with high fluoride contamination in drinking water, this varying from 1.0 to 48 mg per litre as against the World Health Organization’s permissible limit of up to 1.5 mg per litre. Former principal of government dental college, Dr K.S.G.A. Nasser, says, “Patients from Salem, Ariyalur, Srivilliputhur, Tiruchengode, Namakkal and Dindugul are mostly affected by dental fluorosis and skeletal fluorosis, diseases that weaken the teeth and cause joint pain. People in these areas use untested groundwater directly which is high in fluoride.

But there is no study that gives the number of people consuming fluoride content water” “If a child drinks water with high fluoride continuously, she will be affected by dental fluorosis in about 10 to 15 years and can be affected by skeletal fluorosis in about 40 to 45 years,” he notes. General secretary of Doctors Association for Social Equity, Dr G.R. Ravindranath, says, “The public are not aware of the fluoride content in water. They are worried only about salt content and that, too, is measured only by taste.”


Dr S.M. Balaji of Balaji Dental Hospital said, “There is no valid nor recommended cost-effective household method to reduce the additional fluoride content. There are some expensive portable water cleaning systems, like reverse osmosis, deionisers and activated alumina-based water treatment, but their efficacy has not been studied.”

He said the ‘Nalagonda Technique’, originally introduced in Nalagonda in Andhra Pradesh, was found to be effective. It used the alumina-based flocculation method. According to the Hydrology and Water Resources Information System for India, over 90 million people, including about 6 million children, in the country in more than 200 districts, are affected by dental, skeletal and/or non-skeletal fluorosis.

Fluoride monitoring is carried out at 1,286 observation wells in the state by the Tamil Nadu water supply and drainage board twice a year before and after the monsoon. About 121 blocks in 19 districts have high fluoride concentration in groundwater .As per its report, the health ministry has also urged immediate focus on drinking water and sanitation, this being in line with the Prime Minister's 'Swachch Bharat' campaignand sought an assurance that people in the areas identified get safe drinking water. Other states on the culpable list include Rajasthan, Telangana, Karnataka, Madhya Pradesh and Assam.