Fluoride in Drinking Water


On January 25, 1945 Grand Rapids, Michigan became the first municipality to add fluoride to drinking water in an effort to prevent tooth decay. Nearby Muskegon’s drinking water was left unfluoridated as the experiment's control city for comparison purposes.

Following this trial there was no scientific consensus that fluoridation reduced tooth decay in children, yet it was hailed a public health victory. This practice is still supported by the US Centers for Disease Control (CDC) and approximately 70% of municipal drinking water in the United States is currently fluoridated.

Fluoride is also present in a range of consumer products including toothpaste (1,000-1,500 parts per million or ppm), mouthwashes, and fluoride supplements, and food products made with fluoridated water (such as beverages and canned soups) also contain fluoride.

In 2006, the National Academy of Sciences (NAS) produced Fluoride in Drinking Water: A Scientific Review of EPA's Standardswhich reviews the appropriateness of EPA’s 4 parts per million (ppm) maximum contaminant level goal (MCLG) for fluoride in drinking water.

The NAS report states that “the consistency of the results appears significant enough to warrant additional research on the effects of fluoride on intelligence” and recommends that the EPA update the risk assessment of fluoride to include new data on health risks, better estimates of total exposure from sources in addition to drinking water, and an assessment of the potential neurobehavioral effects of fluoride. A large 2009 study funded by the National Institutes of Health found no significant relationship between individual fluoride ingestion and tooth decay.

The CDC has recommended that infant formula not be prepared with fluoridated drinking water and that infant exposure from toothpaste be limited. Currently CDC states the following: "If your child is only consuming infant formula mixed with fluoridated water, there may be an increased chance for mild dental fluorosis. To lessen this chance, parents can use low-fluoride bottled water some of the time to mix infant formula." However, the EPA has yet to review available data on health effects.

The controversy over water fluoridation continues even while there is clear evidence of adverse effects from overexposure.

ScienceAmanda Verdery Young