Since 1945, many American water systems have adjusted the amount of natural fluoride concentration of a community's water supply to a level that is best for the prevention of dental decay. This process is known as "drinking water fluoridation".
Fluoride is a naturally occurring ion found in varying amounts in water, air and soil. Fluoride at optimal concentrations for oral health is safe and effective in reducing tooth decay by 20% to 40%. Drinking water fluoridation is beneficial to adults as well as children in preventing tooth decay.
The American Dental Association (ADA), the American Medical Association, the Centers for Disease Control and Prevention (CDC), the U.S. Public Health Service (USPHS), the World Health Organization (WHO), the American Water Works Association (AWWA) and many other public health and professional organizations recognize the public health benefits of drinking fluoridated water.
The 3 primary agents used in drinking water fluoridation are sodium fluoride, sodium fluorosilicate and fluorosilicic acid.
Drinking water's fluoride content is limited under federal and state regulations. The U.S. Environmental Protection Agency (USEPA) has established a Maximum Contaminant Level of 4 mg/L for fluoride, a Maximum Contaminant Level Goal of 4 mg/L, and a Secondary Maximum Contaminant Level of 2 mg/L to avoid cosmetic staining of teeth for children less than age 9. EPA considers all water with fluoride content less than 4 mg/L to be safe for consumption. California has a standard of 2 mg/L for fluoride.
Consumption of water with a fluoride level above 2 mg/L increases the risk for dental fluorosis in developing teeth. The vast majority of dental fluorosis is a whitening of the biting edges of the teeth, and are considered a minor cosmetic effect. Consumption over long periods to excessively high levels of fluoride can cause moderate or severe forms, which is a staining of the permanent teeth. To minimize the risk of fluorosis, children under age 9 should not drink water that has more than 2 mg/L of fluoride.
A detailed review by the National Research Council in 1993 found finds no links between low-level fluoride ingestion and occurrences of cancer, kidney disease, gastrointestinal disorders, immunological disorders, reproductive effects, genetic disorders, or bone fractures.
As part of "Healthy People 2010" the U.S. Department of Health and Human Services set a goal of increasing the proportion of the American population served by community water systems with optimally fluoridated water to 75% by the year 2010.
In 2000, the CDC estimated that 66% of people using community water systems, or 162 million people, had access to fluoridated water.
Water plant personnel perform a valuable public service by carefully adjusting the level of fluoride in water to improve the dental health of the community.
More about Community Water Fluoridation from the Centers for Disease Control and Prevention.