National Toxicology Program Finds No Safe Level of Fluoride in Drinking Water; Water Fluoridation Policy Threatened

March 21st, 2023 | Fluoride Action Network

After a 6-year long systematic review of fluoride’s impact on the developing brain, a court order has led to the National Toxicology Program (NTP) making public their finalized report that was blocked by US Department of Health and Human Services (HHS) leadership and concealed from the public for the past 10 months. The NTP reported 52 of 55 studies found decreases in child IQ associated with increase in fluoride, a remarkable 95% consistency. The NTP’s report says:

“Our meta-analysis confirms results of previous meta-analyses and extends them by including newer, more precise studies with individual-level exposure measures. The data support a consistent inverse association between fluoride exposure and children’s IQ.”

A meta-analysis is when information from all the relevant studies are combined to get a fuller and unbiased overall picture, rather than just looking at individual studies in isolation.

The NTP’s meta-analysis also put the magnitude of harm into perspective:

“[R]esearch on other neurotoxicants has shown that subtle shifts in IQ at the population level can have a profound impact on the number of people who fall within the high and low ranges of the population’s IQ distribution. For example, a 5-point decrease in a population’s IQ would nearly double the number of people classified as intellectually disabled.”

So, while an average drop of 5 IQ points in a population might sound small it is huge from a public health perspective. Furthermore, the NTP acknowledged there was the potential for some people to be more susceptible than average, so those people could lose much more than 5 IQ points. Those susceptible individuals could lose 10, 15, 20 or more IQ points which would likely cause profound lifetime negative consequences.

The five independent peer-reviewers of the NTP report all voted to accept the review’s main conclusion and lauded the report. Their comments include: “what you have done is state-of-the-art”; “the analysis itself is excellent, and you thoroughly addressed comments”; “Well done!”; “Findings… were interpreted objectively”.

The newly released documents include comments from the NTP’s own experts confirming that the report’s conclusion that fluoride can lower IQ does apply to communities with water fluoridation programs.  NTP report says the evidence is not just in those who drink water with higher fluoride concentrations exceeding the World Health Organization (WHO) recommended maximum level of 1.5 mg/L. Furthermore, the WHO guideline was set in 1984 to protect against more severe forms of dental fluorosis and neurotoxicity was never considered. Few neurotoxicity studies even existed in 1984.

In numerous responses to comments by reviewers of the report, the NTP made clear that they had found evidence that exposures of at least some people in areas with fluoridated water at 0.7 mg/L were associated with lower child IQ.

For example, when an unnamed government fluoridation proponent claimed:

“The data do not support the assertion of an effect below 1.5 mg/L…all conclusory statements in this document should be explicit that any findings from the included studies only apply to water fluoride concentrations above 1.5 mg/L.”