Editor’s note: The Defender is providing daily updates on the landmark trial pitting Fluoride Action Network against the U.S. Environmental Protection Agency. The trial started Jan. 31. To read previous coverage, click here.
The former scientific director of the National Toxicology Program (NTP) on Monday took the stand on the fourth day of a landmark trial on water fluoridation, despite efforts by the U.S. Environmental Protection Agency (EPA) to scuttle his testimony.
Brian Berridge, DVM, Ph.D., testified about the initial findings in the NTP’s draft report linking fluoride to lower IQ in children.
Berridge also outlined the process leading up to the court-ordered release of the report in March 2023. He was limited to discussing the formal NTP report publication process — not his thoughts on whether political concerns may have influenced or delayed that process — because of an April 2023 ruling that those observations fall outside the scope of the trial.
However, The Defender later in the day caught up with Berridge, who was able to speak more freely about his concerns.
Now retired, Berridge said that at the time, he was annoyed by how the NTP report publication process played out because he believed it was an outcome of public health agencies’ desires to protect the practices they already have in place.
As a result, he said, public health officials are ignoring that some people are being exposed to fluoride at high levels.
“This lack of consideration for all the possible people who could be harmed by [water fluoridation] so that we don’t implicate something that we have intentionally done bothers me a lot,” he said.
As an outcome of the agencies protecting their existing practices, the necessary research on fluoride exposure hasn’t been done, despite major indicators that it needed to be investigated, Berridge said.
Food & Water Watch, Fluoride Action Network, Moms Against Fluoridation and other advocacy groups and individuals are suing the EPA in a bid to force the agency to prohibit water fluoridation in the U.S. due to fluoride’s toxic effects on children’s developing brains.
In December 2023, the EPA moved to exclude Berridge’s testimony, arguing that he would speak to the political influence allegedly exerted to stop publication of the NTP’s report on fluoride, rather than to the scientific findings in the report, which federal Judge Edward Chen previously ruled must be the focus of the trial.
The NTP, a subagency within the U.S. Department of Health and Human Services (HHS) that produces scientific research meant to inform policymaking, concluded in the report that prenatal and childhood exposure to higher levels of fluoride is associated with decreased IQ in children.
It also found that given that children are exposed to fluoride from multiple sources, there was “no obvious threshold” at which fluoridating water would be safe.
The NTP sought to publish its report in May 2022, but dental officials at the Centers for Disease Control and Prevention (CDC) and the National Institutes of Health National Institute of Dental and Craniofacial Research (NIDCR) pressured HHS Assistant Secretary for Health Rachel Levine to prevent the review from being published.
Levine told the NTP to not publish the report but to put it on hold and allow for further review.
Plaintiffs submitted documents obtained via the Freedom of Information Act (FOIA) revealing this intervention to the court prompting Chen to rule that the trial should go forward using the draft report from the NTP.
American Dental Association sought to suppress NTP report
During Monday’s testimony, Berridge told the court the first draft of the NTP report classified fluoride as a hazard.
Then, because the NTP recognized the controversial, or “sensitive” nature of the fluoride issue, it took the unusual step of asking the National Academies of Sciences, Engineering, and Medicine (NASEM) to review the report — in addition to the standard external expert peer reviewers — to lend weight to the NTP’s findings.
In response to NASEM’s comments, the NTP decided to forgo making a formal hazard classification for fluoride, instead publishing a “state-of-the-science” report that would present the data and allow policymakers to evaluate the evidence themselves
That determination was “a reflection of the ‘sensitivity’ of the issue and the challenges in making a hard conclusion,” Berridge testified.
The NTP also shared the report with other interested agencies within HHS.
In early 2022, Berridge signed off on the report and as scientific director, he considered it final — a decision that typically leads to immediate publication. However, in this case, Levine blocked the report and sent it for further review by the NTP’s Board of Scientific Counselors.
On cross-examination, the EPA’s attorney used the NASEM review to try to discredit the findings of the NTP report, suggesting the report remains in draft form because of some inadequacy.
American Dental Association (ADA) spokesperson Howard Pollick, a long-time fluoridation supporter who is attending the trial, echoed the EPA attorney’s position.
Pollick told The Defender he didn’t read the report, but that it hadn’t been “acceptable” in peer review and is therefore incomplete and shouldn’t be published.
In May 2023, Pollick said, he submitted a letter to this effect to the NTP’s board, which was adjudicating the final publication of the report.
Plus, he said, anything is toxic at high levels. “If you drink too much water in a period of time you can die.”
He also said fluoridated water is important for addressing tooth decay, especially for parents who “don’t pay too much attention” to what their children are eating or how often they clean their teeth.
Documents obtained by plaintiffs through FOIA revealed the ADA had early access to the NTP report and actively sought to prevent its publication.
Was NTP report modified to ‘fit commercial interests’?
Berridge told The Defender the quality of the NTP report was unimpeachable. “You would be hard-pressed to find an analysis that has the level of rigor and review that this particular analysis does,” he said.
Contrary to arguments put forward by the EPA, the extensive level of review the report was subjected to had nothing to do with the quality of the work. “I think that the incredibly unusual level of review here is a reflection of the fact that there are significant stakeholder interests,” Berridge said.
“Some of those are more biased than others,” he added.
Berridge said he thought the “challenges” brought by reviewers were “misguided” and that some of the input, namely from other agencies within HHS, was “not supported by the evidence” and so the NTP declined to incorporate those suggestions.
When asked if an administrator at HHS had ever previously intervened to block the publication of a scientific report, as Levine did with the NTP report, he said, “It certainly had never happened during my tenure there. I’m not aware of that having happened in the past.”
Berridge also commented on his emails, made public via FOIA, where he voiced concerns that efforts were being made to “modify [the NTP report] to fit commercial interests,” and that the unprecedented challenges and number of reviews had been “obstructive.”
Berridge said:
“I did voice concerns that I felt like there was an extraordinary amount of challenge coming from some of the stakeholders, and these are stakeholders that would have an obvious bias.”
“Obviously the CDC division of oral health would have a bias. This is something that they have advocated for a very long time, and NIDCR is sort of a research representative of the dental community, obviously it would have a bias.”
‘The public has a right to know’
Berridge told The Defender that although water fluoridation was a major point of discussion in the lawsuit, the NTP didn’t narrowly look at water fluoridation.
The NTP’s findings, he said, reflect the possible health effects that come from a child’s total exposure to fluoride.
“Water fluoridation is just one possible source of exposure,” Berridge said. It can’t be considered in isolation given that there are also many other simultaneous possible points of fluoride exposure.
The risk assessors have to consider the evidence of broader exposure to assess whether people are being exposed to levels that present a hazard.
Berridge told The Defender:
“The reality of it is, is that there are people in the United States who are being exposed to extraordinary levels. And so whether you believe that water fluoridation is a potential source of hazard because of the fluoride is irrespective of the fact that there are people who are being exposed that are at risk because they also have different sources of exposure [in addition to water].”
He called for more research. “This potential was raised as far back as 2006 by the National Research Council,” he said. “We have had lots of opportunities since 2006 to really put a lot of effort into understanding whether in the United States or anywhere else we are unfortunately and unintentionally exposing folks to levels of fluoride or any other agent that could be a cause of harm.
We haven’t done “our due diligence,” Berridge said. “We didn’t go out and do the kinds of studies that would’ve made this much clearer and that I find bothersome as well.”
He added:
“For me as a scientist, the impetus here is to do what it takes to get the evidence to make sure that we’re not doing something that is putting people at risk, particularly when it relates to children.
“And I personally believe we could have done a better job than we’ve done, and that’s where we ought to be focusing our attention on clarifying the evidence, not getting into debate.”
Berridge also said that although the NTP’s work is meant to support regulators and policymakers, its research should also inform the general public, so people can make their own decisions about how they mitigate risk in their lives.
“The public has a right to know what the evidence is so that even if the EPA is not making a change or the FDA [U.S. Food and Drug Administration] or whoever the regulators are, then at least people can make informed decisions,” he said. “And when you’re not permitted to put that evidence in the public sphere, it prevents people from being able to do that.”
Berridge retired from the NTP last year. He said the NTP report controversy wasn’t the only factor in his retirement, but it certainly influenced his decision.
“I had concerns that this didn’t play out in keeping with the policy as it relates to protecting scientific integrity,” Berridge said. “I’m not telling you anything that’s not in print, but I’m also not walking back from it because I believe it’s true,” he said.
