Court Tells EPA to Consider Fluoride Risk, to Dentists’ Dismay

October 7, 2024 by Michael Schulson

A federal judge last month handed a major victory to opponents of water fluoridation, capping a seven-year legal battle over whether the U.S. Environmental Protection Agency has failed to protect the public from potential toxic effects of fluoride, which is added to the tap water of around 200 million Americans.

The decision is sure to invite further scrutiny of the contested science behind it — and of the highly unusual legal process that could transform a flagship public health practice.

Many experts say water fluoridation is a safe, crucial tool for preventing tooth decay. Critics say fluoridated water has little dental value, and they point to some studies suggesting that swallowing fluoride may harm developing brains.

The ruling from Judge Edward M. Chen requires the EPA to respond to those safety concerns, even though the science is far from settled. “It should be noted that this finding does not conclude with certainty that fluoridated water is injurious to public health,” Chen wrote. But, he added, “there is an unreasonable risk of such injury, a risk sufficient to require the EPA to engage with a regulatory response.”

That regulatory response could dramatically revise community fluoridation policies in the U.S., or even end the practice altogether.

Dental experts have reacted with concern to the ruling, which they say is grounded in flimsy science. “Clearly it’s going to raise many, many questions from the public and even from the profession,” said Scott Tomar, an expert in public health dentistry at the University of Illinois-Chicago and a member of the American Dental Association’s National Fluoridation Advisory Committee.

Both the ADA and the American Academy of Pediatrics have put out statements affirming their support for water fluoridation and expressing concern about the ruling.

The EPA’s response could dramatically revise community fluoridation policies in the U.S., or even end the practice altogether.

Jeff Landis, an EPA spokesperson, declined to comment on the ruling. It’s unclear whether the agency plans to appeal, or how long a rulemaking process might take.

Behind the decision is a little-noticed section of the Toxic Substances Control Act, or TSCA. Under the law, citizen groups can ask the EPA to tighten or impose regulations on chemicals that they think pose dangers. If the EPA refuses, the citizens can sue them in federal court.

Typically, when people file that kind of suit against a regulator, they have to convince a judge not just that the agency is wrong, but that it has acted in a manner that’s arbitrary and capricious. But buried in the law was an unusual provision: Citizens could sue the EPA in court, and the case would proceed de novo, meaning it would start from scratch. Essentially, the judge would hear all the scientific evidence and then make an independent judgment on whether the chemical posed a risk to the public before sending it back to the EPA to decide whether and how to regulate the chemical.

“You are really asking a judge to step into the shoes of a scientist.”

“Normally, the moment that a citizen group walks in, sets foot in the courthouse, there’s a thumb on the scale for the agency, because the court is only asking the question of, ‘Was the agency’s decision arbitrary and capricious?’” said Sanne Knudsen, a professor of environmental law at the University of Washington. But under this provision of the law, “the moment that the citizen group walks into the courthouse, they’ve got a judge who is at least going to look at it through fresh eyes.”

That process, Knudsen said, could be problematic: “You are really asking a judge to step into the shoes of a scientist.”

But, Knudsen and other legal experts said, the provision also offers an opening for public interest groups who feel that the EPA has not done a good job to try their case in a wholly different, very public forum — the chambers of a federal judge.

“Chemicals that are going to creep through and end up in these de novo proceedings are the ones that have been hung up by the politics,” said Wendy Wagner, an environmental law scholar at the University of Texas at Austin.

The fluoride lawsuit, she said, seems to be the first of its kind: “This is extremely novel and pathbreaking.”


In the TSCA rules, anti-fluoridation activists, who have long complained that the EPA treats fluoride differently from other chemicals, saw an opportunity. In November 2016, the Fluoride Action Network, an activist group, and others filed a petition asking the EPA to regulate the addition of fluoride to drinking water. When the EPA refused, the activist groups sued — their case bolstered, in part, by changes to TSCA that Congress had approved in 2016 with bipartisan support.

The activist groups had a growing, but highly controversial, body of scientific evidence to draw from. Scientists had long known that very high doses of fluoride can damage bones and teeth. Since the early 1990s, a modest body of scientific research has also suggested that fluoride can harm brain development, leading to measurable drops in children’s IQ. Many of those early studies, experts say, were poorly done. And some took place in communities where fluoride naturally occurs in the water at levels much higher than the 0.7 milligrams per liter that U.S. communities currently add to their tap water.

Still, the signs of negative IQ effects were consistent enough for some experts to raise questions. “More research is needed to clarify the effect of fluoride on brain chemistry and function,” a panel of experts convened on behalf of the EPA wrote in 2006.

Starting in 2015, the National Toxicology Program, an office housed within the National Institutes of Health, began preparing a major review of fluoride research — at least partly in response to a nomination from the Fluoride Action Network.

Around the same time, the government institute that houses the NTP helped fund new studies in Canada and Mexico that looked at levels of fluoride in pregnant women’s urine, and then investigated whether those levels were correlated with a drop in IQ in their offspring. The researchers found some signs of an effect.

The results concerned some environmental health researchers. “As the literature continued to accumulate, we were more and more convinced that there were no single flaws that could explain the consistency in the findings,” John Bucher, a retired NTP toxicologist and a lead author of the report, told Undark in an interview conducted late last year.

In August, after years of delays, the NTP released its final report, finding, with moderate confidence, that fluoride exposures at levels above 1.5 mg/L “are consistently associated with lower IQ in children.”

“The bottom line is that the overwhelming majority of those studies had either significant flaws or were, frankly, just not looked at through a critical eye.”

Chen, in his ruling, leans heavily on the NTP report. Even though the report points to evidence of harm only at levels more than double the 0.7 mg/L found in U.S. tap water, he writes, the law requires the EPA to put in place a more sizeable buffer. Fluoride, he writes, is “hazardous at dosages that are far too close to fluoride levels in the drinking water of the United States.”

Some critics have said that the research behind these conclusions is riddled with problems. It can be difficult to get clear answers from the inevitably muddled data on which large epidemiological studies rely. Results among studies have sometimes been inconsistent — some, for example, find the effect only in boys, while others do not. Other critics have raised concerns about studies that measure fluoride in pregnant women’s urine to estimate the amount that circulates in the mother’s blood and passes to the fetus. The relationship between urinary fluoride levels and fluoride in the rest of the body, they say, can be tenuous, introducing additional uncertainty about the connection between fluoride and IQ.

“The bottom line,” said Tomar, “is that the overwhelming majority of those studies had either significant flaws or were, frankly, just not looked at through a critical eye.”


The American Dental Association declined to make anyone available for an interview, and it is unclear what the organization’s next steps will be. Tomar, the dental expert, said he and his colleagues weren’t dwelling on worst-case scenarios — yet. But, he said, he expects some communities to revisit their policies in light of the ruling. (Already, some municipalities have suspended fluoridation, citing Chen’s decision.)

If fluoridation is rolled back widely, Tomar said, “I think the onus will be on states and local communities to now come up with alternative preventive measures, which, frankly, will be far more difficult and far more expensive.”

For anti-fluoridation advocates, the ruling represents a striking reversal after years on the margins.

Reached by phone two days after the ruling, Paul Connett, the founding director of the Fluoride Action Network, was declaring victory: “The two nails in the coffin were put with the NTP review and our court case.”

For anti-fluoridation advocates, the ruling represents a striking reversal after years on the margins.

Connett first began campaigning against fluoride in 1996. Like other anti-fluoridation activists, he courted a range of allies: In 2010 and 2011, for example, he was interviewed by Alex Jones, the famed Texas conspiracy theorist. (The appearances were “highly problematic,” he acknowledged, adding that he disagreed with many of Jones’ ideas. “But for us, it was a way of reaching millions of people that we could not reach.”)

Connett’s son, Michael, was the lead lawyer in the case for the plaintiffs. Hearing the ruling, the elder Connett said, “was a dream come true.” But, he said, he was also aware of years of setbacks.

Speaking after the ruling, though, he sounded optimistic. “We won,” he said, then paused. “For the moment, we’ve won.”

This article was originally published on Undark. Read the original article.

Leave a Reply

Your email address will not be published. Required fields are marked *