The Anti-Fluoride Movement Vaults Into the Mainstream

At an aging water treatment plant north of New York City, the fluoride solution was leaking from a pump. It was intended to be added to the drinking water piped down from the Catskills, to strengthen teeth and prevent dental decay. But instead it was dripping onto the ground, where it had soon eaten through the concrete.

That leak, in 2012, was followed by repairs and upgrades that took more than a decade. For much of that time, the town of Yorktown, in northern Westchester County, drank unfluoridated water. By the time the new fluoridation system was up and running in August 2024, the town supervisor, Ed Lachterman, had detected a shift in public opinion.

He had grown accustomed to hearing from people who insisted that Yorktown’s water remain fluoridated. “It was, ‘fluoride, fluoride, fluoride,’” he recalled. But in the intervening years, his constituents seemed far more wary, voicing concerns about fluoridated water’s effect on the brain or framing it as an issue of autonomy — “my body, my choice,” he recalled.

A month after resuming fluoridation, Mr. Lachterman reversed course, suspending it in September. He cited an unexpected development: A federal judge in San Francisco had just concluded that fluoride, long known to be toxic at high levels, “poses an unreasonable risk of reduced I.Q. in children” even in amounts close to what is typically added to the nation’s drinking water. The judge ordered the Environmental Protection Agency to do something about it.

His ruling followed a report released in August by the National Toxicology Program, part of the U.S. Department of Health and Human Services, that concluded “with moderate confidence” that higher fluoride exposures “are consistently associated with lower I.Q. in children.”

The judicial ruling was a surprising development in the nation’s running debate over the virtues and perils of adding fluoride to our water supply, a controversy that over 80 years has veered across a lot of territory — from public health to conspiracy theories. The debate had seemed to be settling down. A quarter-century ago, the Centers for Disease Control and Prevention had declared water fluoridation to be one of the 20th century’s greatest public health achievements, pointing to the dramatic decline in cavities and tooth decay.

But there has been a shift in the debate over fluoride. It occurred as trust in the nation’s public health system eroded during the Covid-19 pandemic. And it reflects growing public concern over the toxins and substances that accumulate in our body, like microplastics and the “forever chemicals” known as PFAS.

Then, in November, in the days before Donald J. Trump was re-elected, Robert F. Kennedy Jr., a Trump acolyte, pledged that an incoming Trump administration would advise local water systems “to remove fluoride from public water.” His position wasn’t surprising: Water fluoridation has long been a target for Mr. Kennedy, along with vaccines, pesticides and processed foods. But to many in the medical establishment, it was astonishing that fluoridation was suddenly a hot-button issue during a presidential election and, now that Mr. Kennedy has been tapped to be health secretary, an item on Mr. Trump’s agenda.

No less surprised was Stuart Cooper, but for completely different reasons. Mr. Cooper is the executive director of the Fluoride Action Network, a national group that opposes fluoridation and that was among the plaintiffs in the fluoride lawsuit in San Francisco. Though he was excited that fluoridation was “a presidential issue,” he was also worried: If the Trump administration forced the issue, it could alienate Democrats from embracing the cause.

“We don’t want Trump to do a unilateral action here,” Mr. Cooper said. “We’re already winning without him.”

A ‘Communist plot’

From the moment that fluoride was introduced into the water supplies of American cities, starting in 1945, critics questioned the safety. Dentists pointed to a direct correlation in the decline in tooth decay and improved oral health thanks to fluoridation. But the debate often veered away from science and toward conspiracy theories.

Members of the far-right-wing John Birch Society had denounced water fluoridation as a Communist conspiracy — a bent of mind captured by the character Brigadier General Jack D. Ripper in Stanley Kubrick’s film “Dr. Strangelove,” a Cold War satire. “Have you ever seen a Commie drink a glass of water?” General Ripper observes — proof that fluoridated water was a “dangerous Communist plot.”

But the issue receded somewhat after the Cold War, and by 2012, nearly 75 percent of Americans on public water systems drank fluoridated tap water. That would be the high-water mark.

A decade later the percentage has dropped slightly, to 72.3 percent, according to the C.D.C.

Even New York City has lowered the amount of fluoride it adds to drinking water. A glass of tap water in New York today has about 30 percent less fluoride than it did 15 years ago.

Fluoridation can trace its beginning to 1901, when a young dentist in Colorado Springs began to investigate why so many of his patients had brown spots on their teeth. The culprit, it was determined, was the water, which had naturally high levels of fluoride, a mineral found in soil and rocks. But dentists also realized that though unsightly, these teeth resisted decay.

In 1944, Kingston and Newburgh, about 35 miles apart along the Hudson River, agreed to participate in an experiment. Fluoride would be added to Newburgh’s water, so that it made up about 1 or 1.2 parts per million. No fluoride would be added to Kingston’s water. After a decade, the results were clear: Children in Newburgh had roughly half as much tooth decay as Kingston children.

After long debate, fluoridation came to New York City in 1965. The city’s Board of Health set the fluoride level at “approximately 1.0 part per million” but no greater than 1.5 parts per million. That provision is still on the books.

But the question has remained: What is the optimal level?

A shifting consensus

In 2011, the federal government recommended that water authorities lower fluoride levels to 0.7 parts per million, citing improved dental hygiene and the availability of fluoride toothpaste. By 2015 New York City had done so, according to Beth DeFalco, a spokeswoman for the city’s Department of Environmental Protection.

Too much fluoride has long been known to not only stain teeth but also cause skeletal fluorosis, which weakens bones and causes joint pain. But a growing body of research has examined whether higher fluoride levels pose a risk to brain development. That research proved decisive in the San Francisco court ruling, which noted that pregnant women and infants were especially vulnerable.

Dr. Ashwin Vasan, who stepped down last month as New York City’s health commissioner, said the answer wasn’t to get rid of fluoridation entirely but to reconsider the dosage: “What are the levels of fluoride that are safe and at what level does it become unsafe?” he asked.

In New York, the front line in the debate over fluoridated water had long been Queens’s eastern border. In the 1990s, Long Island towns began to stop fluoridating their water supplies, amid concerns about contaminants.

But the water supply on Long Island is not only turning increasingly salty but is also polluted with toxic chemicals from its industrial past. As a solution, the state Health Department has considered piping in New York City water — which comes from the Catskill Mountains and tributaries of the Delaware River. But a 2022 government study notes a potential challenge: It is unclear whether Long Island communities would accept “fluoridated NYC water.”

Elsewhere in New York State, citizens are demanding fluoridated water. Albany, which had never added fluoride to its water, passed a bill earlier this year to start.

In Buffalo, a modern version of the Newburgh-Kingston experiment is playing out, though without anyone’s consent. In 2015, Buffalo stopped adding fluoride to its water when it began to upgrade equipment at a water treatment facility. But Buffalo, which had outsourced management of drinking water to a private company, provided little notice of the change to residents. Years went by without much progress on the upgrade. It was not until 2023, following a report in The Buffalo News, that many Buffalo residents learned their water had no fluoride.

Dentists have said they now see more tooth decay in children living in the city of Buffalo than expected, according to news reports. A class-action lawsuit on behalf of residents demands more than $210 million to help families pay for increased dental costs and other damages. In September, Buffalo announced it would resume fluoridating the water, after a nine-year pause.

Audio produced by Adrienne Hurst.