ADA urges National Toxicology Program to reconsider monograph

Washington — The ADA is reaffirming its support of the safety of community water fluoridation and asking the National Toxicology Program to change its classification of fluoride from a presumed neurotoxin to an unknown neurotoxin.

The Association shared this request with the National Academies of Sciences, Engineering, and Medicine Board on Environmental Studies and Toxicology in comments filed ahead of its Oct. 19 review of the Revised NTP Monograph on Fluoride Exposure and Neurodevelopmental and Cognitive Health Effects.

In the comments, then-ADA President Chad P. Gehani, D.D.S., and Executive Director Kathleen T. O’Loughlin, D.M.D., explained that currently, there is not a wide body of literature examining fluoride as a potential neurotoxin. They also pointed out that what literature is available — which the National Toxicology Program consulted to create its monograph — is “either lacking, unreliable, inconclusive, conflicting or subject to widespread interpretation.”

The ADA also pointed to NTP’s own acknowledgement that its claim of “presumed” neurotoxin is based on a “low-to-moderate level of evidence” and said that if NTP moves forward with this claim, it is critical to “clearly and consistently qualify” that “the claim applies only to abnormally high levels of fluoride exposure of more than 1.5 mg/L.” Fluoridated drinking water in the U.S. is set at 0.7 mg/L.

“Failing to do so will endanger the public’s health and leave the agency vulnerable to charges of risk bias,” Drs. Gehani and O’Loughlin wrote.

The ADA also said the “preponderance of scientific literature has not demonstrated a relationship between exposure to fluoride at levels recommended by the Centers for Disease Control and Prevention and the U.S. Public Health Service (0.7 mg/L) and neurocognitive development.” The ADA pointed out that there are places in the monograph where NTP acknowledges that studies of fluoride exposure at levels recommended for community water fluoridation (0.7 mg/L) “have not consistently or reliably demonstrated effect on cognitive neurodevelopment,” noting this key finding is “overshadowed by the frequently repeated blanket statement that fluoride is presumed to be a neurotoxin — without any context or qualification.”

The ADA also said that by failing to address the oral health benefits of fluoride in the monograph, NTP will potentially be generating confusion about the safety of community water fluoridation at levels recommended by the CDC and UPHS (0.7 mg/L).

“This lack of clarity will add to the many myths and misperceptions about community water fluoridation, and likely undermine state and local efforts to expand the practice,” Drs. Gehani and O’Loughlin wrote.