February 22, 2022
Rick Woychik, Ph.D.
National Institute of Environmental Health Sciences
111 TW Alexander Drive
Durham, NC 27709
Re: ADA’s Comments on NTP Report
Dear Dr. Woychik,
We write today to comment on a letter that the American Dental Association (ADA) recently wrote to the National Toxicology Program (NTP), in which the ADA implored the NTP to forego the conclusion that fluoride is a neurotoxicant at any exposure level.1
It is important that the NTP keep in mind the biases that the ADA brings to the issue of fluoride safety. The ADA is a trade organization that prioritizes political advocacy for water fluoridation over and above objective assessments of the program’s safety and effectiveness. An example of the ADA’s politicized approach to the fluoride issue can be seen in its “White Paper on Fluoridation” (1979), where it states:
Individual dentists must be convinced that they need not be familiar with scientific reports of laboratory and field investigations on fluoridation to be effective participants in the promotion program and that nonparticipation is overt neglect of professional responsibility.2
The ADA’s letter to the NTP is consistent with ADA’s checkered history of lobbying against government actions that could result in more protective public health policies on fluoride. For example, when the Environmental Protection Agency (EPA) first proposed regulating fluoride as a contaminant in drinking water, the ADA asserted that no such regulation was necessary, and that a federal regulation would “undermine the efforts of the dental profession and government in promoting fluoridation of community water supplies.” In its zeal to prevent a maximum contaminant limit for fluoride in water, the ADA asserted that “there is no evidence implicating naturally occurring fluorides as a health hazard even at eight times the optimum level (i.e., 8 ppm) set by the EPA.”3 This remarkably irresponsible assertion highlights the degree to which the ADA prioritizes political advocacy over scientific credibility. Thankfully, the EPA disregarded the ADA’s claim, much to the betterment of the public’s health.
Given the political nature of the ADA, we write to encourage the NTP to give the ADA’s recent letter the minimal weight it deserves. The ADA’s letter itself highlights the ADA’s lack of seriousness in assessing the science, as evident by the ADA’s mischaracterization of the NASEM peer review. The ADA claims that “NASEM noted that NTP failed to provide adequate scientific evidence for its conclusion.” This is incorrect. The NASEM called on the NTP to explain its methodology and findings with greater clarity and transparency (a procedural matter), which is distinct from NASEM stating that the underlying science does not support fluoride being a neurotoxicant (a substantive matter). Importantly, the NASEM committee explicitly stated they did not independently evaluate the underlying scientific evidence and they were not charged with reaching a conclusion as to the hazard rating the NTP should give to fluoride.
In its letter, the ADA urges the NTP to forego classifying fluoride as a neurotoxicant, much like the ADA had once urged the EPA to forego classifying fluoride as a contaminant in water. In both instances, the ADA’s motive is the same: to eliminate hindrances to the political promotion of fluoridation. That motive should be of no concern to the NTP. For the NTP, the only concern should be the science. We write, therefore, to simply encourage the NTP to follow the science, not the political dictates of trade organizations. If the science justifies the conclusion that fluoride is a neurotoxicant at low levels of exposure (which is indicated by a recent benchmark dose analysis of the ELEMENT/MIREC cohort data4), the NTP’s report should not hesitate in saying so.
We have previously provided detailed comments to NTP and to the NASEM committee in response to the draft monographs and reports. In those comments we have explained why, if anything, the draft NTP monographs have understated the strength of evidence supporting a hazard conclusion that is at least the “presumed hazard” category, and could reasonably reach “known hazard.”5 Our comments show how, if the OHAT manual and the protocol for the fluoride neurotoxicity evaluation are faithfully followed, an integration of the evidence and risk of bias ratings would qualify fluoride to be rated at least as a presumed hazard.
Finally, as the stakeholder which proposed that NTP conduct this review, we would respectfully ask for an opportunity to meet with your office to discuss its current status. We are happy to make ourselves available for a conference call (by phone or by Zoom) at your convenience.
Paul Connett, PhD
Fluoride Action Network
2 http://fluoridealert.org/uploads/ada_white-paper.1979.pdf. The quoted passage is on pages 11-12.
4 Grandjean P, Hu H, Till C, et al. A Benchmark Dose Analysis for Maternal Pregnancy Urine-Fluoride and IQ in Children. Risk
Anal. 2021 Jun 8. doi: 10.1111/risa.13767. Epub ahead of print. PMID: 34101876.
5 See, e.g., https://fluoridealert.org/wp-content/uploads/neurath-2020.fan-dose-response-assessment-of-ntp-studies-withcorrections.
pdf and https://fluoridealert.org/uploads/ntp.neurath.submission-to-nas-on-revised-ntp-monograph.10-19-20.pdf