Why RFK Jr. wants to ban fluoride in water

Health and Human Services Secretary Robert F. Kennedy Jr. is expanding his crusade to turn back the clock on federal health policy.

Having undermined the government’s support for childhood vaccines amid the worst measles outbreak in years, he is now targeting another longstanding pillar of American public health: water fluoridation.

HHS will convene a board of experts to review the federal government’s recommendation that communities fluoridate their water, the agency announced on Monday. The Environmental Protection Agency is simultaneously launching a review of the science on fluoride’s health effects.

The end result of those inquiries seems to be a foregone conclusion: Kennedy told the Associated Press that he wanted the government to stop recommending fluoridation. He has called fluoride “industrial waste” and blamed it for an array of health conditions, from neurological damage in children to bone cancer.

Banning fluoride is an integral part of Kennedy’s campaign to Make America Healthy Again. The news of the reviews came on the same day he appeared in Salt Lake City to praise Utah for being the first state to officially ban water fluoridation.

”It makes no sense to have it in our water supply,” Kennedy told reporters. “I’m very, very proud of this state for being the first state to ban it, and I hope many more will come.”

Water fluoridation, which the US government has supported since 1950, has long been considered a major public health win. The Centers for Disease Control and Prevention reported as recently as last year that, based on the best available evidence, fluoride in water reduces tooth decay by 25 percent for children and adults. About three in five Americans now drink fluoridated water from their community water system.

Concerns about fluoridated water’s health effects have been around for decades, too, particularly among conspiracy-minded individuals like Kennedy. Like many conspiracies, it has some basis in reality — but the reality is far more nuanced than Kennedy’s new call for banning it outright would suggest.

As neuroscientist Celia Ford covered for Vox last year, questions around fluoridated water began growing after the US National Toxicology Program stated with “moderate” confidence that exposure to elevated fluoride levels could reduce IQ in children.

That’s a finding worth taking seriously — but only in context. The elevated fluoride levels that were studied in the report were above 1.5 milligrams per liter — more than twice the existing federal guidelines for how much fluoride communities should add to their water. The size of the effect was also fairly small, amounting to 1 to 2 points.

The real concern is for the small minority of people, about 1.9 million, who live near a community water source that already contains more than that 1.5 milligrams per liter of naturally occurring fluoride. (Those folks might want to consider a water filter, Ford wrote.)

As for Kennedy’s other claims, such as fluoridated water’s supposed links to cancer, the CDC has said studies of cancer in areas with high natural levels of fluoride have found no connection.

While Kennedy may be the US’s top health official, he does not have the final word on whether Americans can access fluoride to reduce the risk of cavities. States and localities control community water systems that serve most Americans. Hawaii, for instance, has never approved water fluoridation, though the practice is not outright banned.

That can cut both ways: Kennedy has said he hopes other states and cities follow Utah’s lead, and his support could embolden some state and local officials to move forward with their own bans. But he cannot change state laws on fluoridation; some states, California and Illinois among them, require cities of a certain size to fluoridate their water. They don’t seem likely to take cues from Kennedy.

The good news is that even if Kennedy can successfully encourage more states to embrace his anti-science platform and remove fluoride from their water supply, the ultimate effect on people’s dental health could ultimately be limited. One recent review of the scientific literature noted that water fluoridation studies conducted after 1975, when fluoride was introduced in toothpastes, have found less of an effect on tooth decay than earlier studies had.

But even if the practical impact of Kennedys’ crusade may be marginal, it can still be influential: A plurality of Americans, 41 percent, said in a January 2025 Ipsos poll they didn’t know whether fluoride was harmful and helpful. Now the nation’s top health official is calling for it to be banned. And the effect of such a ban would fall disproportionately on the least advantaged — one in four children living below the federal poverty line experience untreated tooth decay.

Combined with his actions against vaccines, the fear remains that Kennedy’s reckless overhaul of longstanding public health recommendations could undermine public trust in and support for a wide range of public health efforts, some much more important than water fluoridation.