Fluoride is an acute toxin, with a rating slightly higher than lead. It is, in fact, one of the most bone-seeking elements known to human beings. And groundwater in India shows the presence of unhealthy quantities of fluoride. A worrying scenario: daily ingestion of just 2 milligram (mg) of fluoride could result in crippling skeletal fluorosis after 40 years. Excess fluoride causes several diseases, like osteoporosis, arthritis, brittle bones, cancer, infertility in women, brain damage, Alzheimer's disease and thyroid disorders.
The very nature of fluoride increases this danger manifold. Almost half of each day's fluoride intake is retained, and is absorbed by the bones and teeth. It was Gerald Cox, of the Mellon Institute in the US, who first found in 1938 that while 1.0 milligram per litre (mg/l) of fluorine in water prevents dental caries, over 1.5 mg/l causes mottled teeth. The Bureau of Indian Standards (BIS) standard for fluoride content is 1-1.5 mg /l. It is believed that levels above or below this could cause dental decay. Ironically, there is an increased incidence of dental caries, yellow teeth and twisted limbs among people of all age groups in India.
A recent publication of the Geological Survey of India (GSI) names areas that should go on fluoride red alert: Fazilka and Jalalabad in the border district of Ferozepur in Punjab; parts of Gurgaon, Rewari, Mahendergarh, Hisar, Fatehabad and Faridabad in Haryana; Unnao, Rae Bareilly and Sonbhadra in Uttar Pradesh; Sidhi district in Madhya Pradesh; Beed district in Maharashtra; Nalgonda district in Andhra Pradesh and Dindigul district in Tamil Nadu.
Recent studies have shown that the fluoride content in tube-well water in Fazilka is 6 to 12 mg per litre. Almost 70 per cent of Fazilka's population suffers from dental decay. Jalalabad is not much better off. Although the surface water is less contaminated, tubewells pump out water that contains high fluoride content. The affluent farmers, of course, drink 'mineral water'. The irony, though, is that unscrupulous elements are bottling canal water and selling it as mineral water.
Fluoride toxicity is taking its toll. There is a sharp rise in the number of people with 'yellow teeth'. Cases of arthritis are on the rise in Haryana. The fluoride content in the state's groundwater is often as high as 7 to 8 mg/l. Unnao and Rae Bareilly districts of Uttar Pradesh show fluoride content between 2.9 to 15 mg/l. Dental and skeletal fluorosis, known as 'lunj punj' in Unnao, is rampant in these districts. Toothless villagers with twisted limbs are not an uncommon sight. Village Siraha Khera in Unnao faces a social boycott today. No one marries a girl from the village, and no girl wants to be married into Siraha Khera.
The situation in Sonbhadra and Sidhi is completely different. Here, the groundwater fluoride content is below 1 mg/l. This causes rapid dental caries in children and adults alike.
In the vast geographical expanse and varied geological set-up of India, the causes for fluoridation of ground-water are many. Some natural, some human-made. Fluoride-bearing minerals present in rocks are leached out due to various natural processes such as soil-formation. Volcanic activity also releases gaseous fluorine into the groundwater. We have no control over the natural release of fluoride into groundwater.
The contamination of groundwater by industries — brick kilns, aluminium and steel — is, however, preventable. In Faridabad, these industries bore holes in the ground, into which they inject waste. Certain phosphatic fertilisers also cause fluoride to leach into the groundwater. In Unnao, for example, the use of such fertilisers has risen by 5 lakh metric tonnes in the past decade.
Groundwater contamination is an enormous problem. The sooner we accept that, the better. Unless we take fast and determined steps, we are headed towards a very big water crisis. The first step is to identify and seal off contaminated tubewells. Simultaneously, people must be provided with safe drinking water from state-drilled tubewells.
In the affected areas, a massive campaign effort is needed. There should also be promotion of higher calcium and vitamin C intake. Since most Indians cannot afford these, the state must arrange for free distribution. The next step is reduction of fluoride concentration through artificial recharge techniques like flooding of groundwater with surface water.
Ultimately, the impact of drinking water on human health must be acknowledged. The affluent may have their bottled water. The masses cannot afford it. Can toothless voters and crippled soldiers safeguard the world's largest democracy?
V K Joshi is former Director, Geological Survey of Indiahttp://www.environmentportal.in/node/10740