Fluoride is the name given to a group of compounds that are composed of the naturally occurring element fluorine and one or more other elements. Fluorides are present naturally in water and soil.
Virtually all water contains some amount of fluoride. Water fluoridation is the process of adding fluoride to the water supply so that the level reaches approximately 1 part fluoride per million parts water (ppm) or 1 milligram fluoride per liter of water (mg/L); this is the optimal level for preventing tooth decay.
Purpose of fluoridation of water:
In the early 1940s, scientists discovered that people who lived where drinking water supplies had naturally occurring fluoride levels of approximately 1.0 ppm had fewer dental caries (cavities). Many more recent studies have supported this finding.
Fluoride can prevent and even reverse tooth decay by enhancing remineralization, the process by which fluoride “rebuilds” tooth enamel that is beginning to decay.
In 1945, Grand Rapids, Michigan, adjusted the fluoride content of its water supply to 1.0 ppm and thus became the first city to implement community water fluoridation. By 1992, more than 60 percent of the U.S. population who were served by public water systems had access to fluoridated water at approximately 1.0 ppm, the optimal level to prevent tooth decay.
The Centers for Disease Control and Prevention (CDC) considers fluoridation of water one of the greatest achievements in public health in the 20th century.
Water fluoridation in India
Water fluoridation is not practiced in India. Fluorosis is endemic in at least 20 states, including Uttaranchal, Jharkhand and Chhattisgarh. The maximum permissible limit of fluoride in drinking water in India is 1.2 mg/L, and the government has been obligated to install reverse osmosis water treatment plants to reduce fluoride levels from industrial waste and mineral deposits.
Water fluoridation in USA
As of May 2000, 42 of the 50 largest U.S. cities had water fluoridation. According to a 2002 study, 67% of U.S. residents were living in communities with fluoridated water at that time. In 2010, a U.S. Centers for disease control and prevention study determined that “40.7% of adolescents aged 12–15 had dental fluorosis [in 1999–2004]”. In response, the U.S. Department of Health and Human services, together with the U.S. Environmental Protection Agency are proposing, to reduce the recommended level of fluoride in drinking water to the lowest end of the current range, 0.7 milligrams per liter of water (mg/L), from the previous recommended maximum of 1.2 mg/L. This could effectively terminate municipal water fluoridation in areas where fluoride levels from mineral deposits and industrial pollution exceed the new recommendation.
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