Utah is on track to become the first U.S. state to prohibit fluoridation in its public water systems, a decision that comes just weeks after Robert F. Kennedy Jr., a vocal critic of fluoride, was appointed as the head of the U.S. Department of Health and Human Services.
Fluoride, a naturally occurring mineral, is widely recognized for its role in strengthening tooth enamel and preventing cavities. The fluoridation of drinking water has been a key public health measure in the U.S. for decades.
Understanding Fluoride and Its Benefits
Fluoride is present in water, soil, and air and has been proven to help prevent tooth decay by reinforcing enamel and making teeth more resistant to bacterial acid. It can also reverse early signs of decay by replenishing lost minerals in teeth.
Before the widespread adoption of water fluoridation, tooth decay was a major health issue in the U.S. Studies have shown that communities with fluoridated water have significantly lower rates of cavities in both children and adults. Federal health officials have credited fluoridation with reducing complete tooth loss among older adults.
History of Water Fluoridation
In the early 20th century, researchers observed that people living in areas with naturally high fluoride levels in their water had lower rates of tooth decay. This discovery led to the first controlled fluoridation program in Grand Rapids, Michigan, in 1945. A 15-year study involving 30,000 schoolchildren found that fluoridation reduced cavities by over 60%, leading to widespread adoption across the U.S. in the following decades.
Despite its benefits, fluoridation remains a local policy decision, typically determined by municipal governments and local water authorities. There is no federal mandate requiring fluoride in public water systems.
Fluoridation in the U.S. and Global Practices
As of 2022, about 63% of Americans receive fluoridated water, according to the CDC. Costs for fluoridation vary by community size, ranging from approximately 50 cents per person annually in large cities to $3 per person in smaller areas.
Globally, most countries do not add fluoride to their public water supplies. Instead, some nations fortify table salt with fluoride, while others rely on naturally occurring levels in water.
Regulations on Fluoride Levels
The U.S. Public Health Service recommends fluoride levels in drinking water not exceed 0.7 milligrams per liter to maintain dental benefits while minimizing health risks. However, excessive fluoride exposure—above 1.5 mg/L—has been linked to health concerns such as bone fractures, thyroid disease, and nervous system damage. The Environmental Protection Agency (EPA) enforces a maximum fluoride limit of 4.0 mg/L. A federal judge in California recently ordered the EPA to strengthen these regulations.
Fluoride Production and Key Manufacturers
Fluorosilicic acid, the most common compound used in water fluoridation, dissolves rapidly in water to release fluoride. Companies such as J.R. Simplot and Nutrien’s PCS Phosphate Company manufacture this compound. According to the EPA, U.S. domestic production of fluorosilicic acid from phosphate rock totaled approximately 29 million kilograms (32,000 tons) in 2019.
Kennedy’s Stance on Fluoridation
Robert F. Kennedy Jr. has long opposed water fluoridation, claiming it is linked to various health risks, including cancer, despite a lack of conclusive scientific evidence supporting these claims.
Expert Views on Fluoride and Recent Studies
The CDC has recognized community water fluoridation as one of the top 10 public health achievements of the 20th century, citing its ability to prevent cavities across all socioeconomic groups. The American Dental Association (ADA) also strongly supports fluoridation, noting that it reduces tooth decay by more than 25% even in an era where fluoride is widely available in toothpaste and other dental products.
However, recent studies have raised questions about fluoridation’s necessity in developed nations. A 2024 Cochrane Database of Systematic Reviews analysis of 157 studies suggested that fluoridated water may now provide only modest benefits, given the widespread availability of fluoride in toothpaste since the 1970s. The study also found insufficient data to assess the impact of stopping fluoridation or its effects on dental health disparities.
In January, a U.S. National Institutes of Health (NIH) study analyzed 74 studies from 10 countries and found an association between higher fluoride exposure and lower IQ scores in children. In four studies with a low risk of bias involving 4,179 children, researchers reported that fluoride levels commonly found in developed nations were linked to lower IQ scores.
While one editorial accompanying the NIH study expressed concerns about fluoride exposure for vulnerable populations, another editorial warned that the study had limitations and should not be used to influence public policy.
With Utah’s move to ban fluoride in its water systems, the debate over fluoridation’s benefits and risks is likely to intensify, potentially influencing policies in other states.
