States Move to Limit Fluoride in Water After RFK Jr.'s Scrutiny

State lawmakers skeptical of federal guidance on fluoride in water are proposing limits or bans on community fluoridation, a decades-long practice credited with reductions in dental decay across the country.

Lawmakers in four states have introduced legislation that would outlaw adding fluoride to community water systems, and four other states are considering bills to make fluoride optional or limit its concentration. Only one, Utah’s, has moved past its original chamber.

The anti-fluoridation legislation comes after President Donald Trump tapped Robert F. Kennedy Jr., a water fluoridation skeptic, to lead the US Department of Health and Human Services. Kennedy was confirmed this week.

Kennedy said on social media that the Trump administration’s Make America Healthy Again campaign will include an advisory telling “all U.S. water systems to remove fluoride from public water” due to alleged health risks like IQ loss and neurodevelopmental disorders.

Health professionals and proponents of community fluoridation say further actions to limit the practice fly in the face of recommendations from the US Public Health Service, the World Health Organization, and leading US medical associations, and have the potential to walk back progress on what the CDC has labeled one of the greatest public health achievements of the 20th century.

State, Community Proposals

In Tennessee, localities can currently choose whether to add fluoride to water sources. But Republican state Sen. Joey Hensley says he wants to ban the practice altogether with Senate Bill 162.

“The benefits, I think, don’t outweigh the risk,” he said in an interview. “We can’t monitor how much water people drink and how much fluoride they’re getting in the water.”

Hensley said his legislation isn’t new—he introduced a similar bill 20 years ago. But after seeing a recent analysis linking high levels of fluoride to lower IQ scores in children, it was time to try again, he said.

Kennedy’s mainstream fluoride skepticism didn’t influence the bill’s timing, but “it helps” the cause, Hensley said, adding “maybe he’ll help us down here to get the bill passed.”

Though recent studies about fluoride’s possible link to IQ scores concerned Kennedy and anti-fluoride advocacy groups, state public health departments and oral health researchers cited flaws in the research and its applicability to fluoride levels found in the US.

“These concerns about risk of fluoride in the water are, I believe, not valid for the amount of fluoride we have in the water,” said Charlotte Lewis, a physician and professor at the University of Washington School of Medicine whose research specializes in oral health.

Communities across the US first began adding fluoride to water in the 1940s after early research indicated a link between the presence of the mineral in water supplies and reduced dental decay and cavities.

The Centers for Disease Control and Prevention estimates that as of 2022, more than 72% of the US population connected to community water systems receive fluoridated water. Today, drinking fluoridated water reduces tooth decay by approximately 25% in children and adults, the CDC said in 2015.

Kennedy’s November social media warnings against water fluoridation were followed by an anti-fluoridation advisory from Florida’s surgeon general, which prompted Florida communities to reconsider their programs. The skepticism continued when states started their spring sessions.

Utah House Bill 81, for instance, would bar the addition of fluoride to a public water system or water that will be introduced into one. It would also explicitly prohibit municipalities and counties from passing ordinances requiring or permitting fluoridation.

Bills in North Dakota and New Hampshire join Hensley’s Tennessee proposal seeking a full ban.

Utah Department of Health and Human Services spokesperson Katie England said in an email that the “health community recognizes the benefits of fluoride for dental health,” but added “there are effective alternative methods of treatment delivery.”

“We are encouraged that the legislation continues to support the benefits of fluoride to overall health by providing access to treatment for Utahns through a prescription at a pharmacy,” England said.

Bills in Arkansas, Kentucky, Massachusetts, Nebraska, and South Dakota stop short of banning fluoridation outright, but would either repeal statewide fluoridation programs or set limits on the amount of fluoride added to water.

The North Dakota Department of Health and Human Services declined to comment on the bill there, with spokesperson Jecca Geffre saying in an email that the department was “still assessing bills and evaluating potential impacts.”

Fluoride’s Safety

At least one state, however, is trying to shore up water fluoridation protections.

In Connecticut, Senate Bill 474, introduced by Democratic state Sen. Saud Anwar, would shield water systems from shifting federal fluoridation recommendations.

Right now, Connecticut’s water fluoridation law is tied to the amount recommended by the US Department of Health and Human Services—which is currently 0.7 mg of fluoride per liter (mg/L) of water.

Anwar’s bill would cement the HHS’s current recommendation into state law.

“We had to do the responsible thing” since federal recommendations may not be based on science for much longer, Anwar said. “We know where RFK stands with some of these issues on public health.”

A National Toxicology Program review published in August said the US health agency had “moderate confidence” that exposures to fluoride concentrations in drinking water higher than the 1.5 mg/L recommended by the World Health Organization are associated with lower IQ in children.

That’s more than double the federal government’s 0.7 mg/L recommendation for fluoride concentrations in drinking water, but significantly lower than the Environmental Protection Agency’s enforceable limit of 4 mg/L.

Another factor that could be influencing lower IQ levels is the overall quality of water in the regions being studied, Lewis said.

“They tend to be convenience samples and done in areas that are quite poor, where there’s really not even access to clean water.”