Good drinking water should contain minerals necessary for our body. Fluoride, for example, is one such mineral, which in small proportions is excellent especially for our teeth. The same mineral in excess starts causing harm to the body. If fluoride is in excess of 1.5 mg a liter, consuming such water can cause dental fluorosis and if it is too much in excess, the body faces the problem of skeletal fluorosis. Dental fluorosis is the first visible sign of excess fluoride consumption and is shown as white or brown mottled teeth. Pitting of teeth may also occur.

Since most rural habitations and many urban habitations depend on deep groundwater, some method is necessary to check the presence of fluoride. The 11th Plan document recently finalized by the Planning Commission puts the issue in perspective. It says, "There are about 2.17 lakh affected habitations in the country with more than half of the habitations affected with excess iron (1,18,088). This is followed by fluoride (31,306), salinity (23,495), nitrate (13,958) and arsenic (5,029) in that order. There are about 25,000 habitations affected with multiple problems."

Removing fluoride from water

Various methods of de-fluoridation of water are available. These include household-level de-fluoridation using activated alumina to community-level de-fluoridation plants. While these work well under careful supervision and ownership, many have failed to survive the test of time simply due to apathy or difficulties in maintenance.

Tap water coming from surface-water sources is generally free from excess fluoride. If, however, a bore well is the source of water used or if water is bought from private tankers, it is a safe practice to check a sample of the water for excess fluoride. A certified water testing laboratory will do a quality test for you with a sample of about two liters. If excess fluoride is detected it must be removed before use for drinking or cooking. Boiling the water does not remove fluoride.

Rooftop rainwater harvesting in sump tanks can give us enough drinking and cooking water for the whole year which is free from chemical contaminants such as fluoride, arsenic and nitrates. Taking steps to recharge groundwater through rainwater harvesting methods is also wise. This is the long run measure to reduce fluoride. Shrinking ground water levels have been reported as one cause for the sudden increase in fluoride in ground water. Sustainable use of ground water resources, keeping the aquifers clean and charged and using the dynamic ground water are measures which will go a long way in ensuring water for all in a climate changing world. Water wisdom lies in realizing the true ecological value of water and taking steps to protect this precious resource.

Source: Planning Commission Eleventh Five-Year Plan, (2007-2012) Volume II Social Sector Cheaper 5^th, Drinking Water, Sanitation, and Clean Living Conditions, Government of India, New Delhi, p.181.

Website: http://planningcommission.nic.in/plans/planrel/fiveyr/11th/11v2/11^thvol2.pdf

(accessed on 18^th June 2009)

The Hindu, The National Daily, Date: 15/12/2007 URL:

http://www.thehindu.com/thehindu/pp/2007/12/15/stories/2007121550261100.htm