Fluoride is a chemical compound that is often found in drinking water and has been the source of great controversy. Fluoride leaches into drinking water from natural soil erosion and from man-made sources such as discharge from fertilizer and aluminum factories. In addition, almost 70 percent of the people in the United States on community water systems drink water with fluoride added. The practice of water fluoridation began more than 50 years ago when studies indicated that low levels of fluoride in drinking water could prevent tooth decay. Water systems typically make the decision to fluoridate drinking water at the local level, although in some instances it is determined by the state. The federal government does not mandate it.
Most municipalities fluoridate their water at 0.7 to 1.2 parts per million, the “optimal level” set by the U.S. Public Health Service more than 40 years ago. However, in some areas, the amount of fluoride in drinking water can exceed this level because of its high naturally occurring concentration or agricultural runoff. In addition, people are exposed to fluoride in household dental products and food. Bottled water can also contain fluoride.
While some research supports the claim that water fluoridation prevents dental cavities, the health risks of excessive fluoride exposure are also well established.