For more than 80 years, American communities have added fluoride to public drinking water to prevent cavities. But research into children’s brain development, declining estimates of dental benefits, and a federal court battle have brought renewed scrutiny to the practice.
By Thomas Whitmore | Rockingham County News
November 2, 2026
ELKTON, Va. — The Town of Elkton is considering a change to its public drinking water that could reopen a debate dating back to the earliest years of modern American public health policy.
On October 19, the Elkton Town Council considered scheduling a public hearing concerning the potential removal of fluoride from the municipal water supply. The proposed hearing date was November 16 at the Elkton Area Community Center.
The proposal comes amid growing scrutiny of a practice that federal health agencies have promoted for decades, even as researchers continue investigating whether fluoride exposure may affect children’s neurological development.
For Elkton residents, the issue raises questions extending beyond dental health: Why did governments begin adding fluoride to drinking water, who promoted the practice, what does contemporary research reveal, and how should potential risks be weighed against established benefits?
How Fluoridation Became American Public Policy
The history of water fluoridation begins not with an attempt to prevent cavities, but with a medical mystery.
In the early twentieth century, Colorado dentist Frederick McKay investigated a peculiar discoloration of children’s teeth. The condition, later identified as dental fluorosis, was eventually connected to naturally occurring fluoride in drinking water.
Researchers subsequently observed that communities with certain levels of naturally occurring fluoride also experienced lower rates of tooth decay.
One of the leading figures in this research was Dr. H. Trendley Dean, a dentist and epidemiologist with the United States Public Health Service.
Dean investigated the relationship between fluoride exposure, dental fluorosis, and cavity prevention. His work helped establish the scientific rationale for adding controlled amounts of fluoride to municipal drinking water.
In January 1945, Grand Rapids, Michigan, became the first American city to deliberately fluoridate its public water supply.
The initiative was initially conceived as a long-term experiment. Researchers intended to observe its effects on dental health over approximately 15 years.
But public-health enthusiasm moved faster than the original research timetable.
By 1950, only five years after the experiment began, the U.S. Public Health Service, American Dental Association, and Association of State and Territorial Dental Directors had endorsed community water fluoridation.
The U.S. Surgeon General encouraged communities to adopt the practice.
That history raises an important question about the relationship between scientific research and public policy: How much evidence should governments require before introducing a substance into a public drinking water system?
Supporters point to early findings that showed substantial reductions in tooth decay. Critics question whether the rapid expansion of fluoridation adequately accounted for possible long-term effects that early dental studies were not designed to investigate.
What began as an experimental approach to preventing cavities gradually became a standard public-health intervention across much of the country.
Federal Researchers Identify Potential Neurological Concerns
One of the most consequential developments in the modern fluoridation debate came in August 2024.
The National Toxicology Program, part of the National Institutes of Health, published a comprehensive systematic review examining fluoride exposure and neurological development.
The review concluded, with moderate confidence, that higher fluoride exposure was consistently associated with lower IQ scores in children.
The finding was particularly relevant to populations exposed to drinking water containing more than 1.5 milligrams of fluoride per liter.
That concentration is more than twice the 0.7 milligrams per liter currently recommended for community water fluoridation in the United States.
The distinction is significant.
The federal review did not establish that fluoridated drinking water at the recommended American concentration causes lower intelligence. Researchers acknowledged that the available evidence was insufficient to determine whether exposure at 0.7 milligrams per liter produced such effects.
Nevertheless, the review demonstrated that fluoride exposure cannot be evaluated exclusively through the lens of dental health.
Its potential neurological consequences, particularly during childhood, must also be considered.
A Study of 74 Investigations Finds an Association with Lower IQ
Additional research published in JAMA Pediatrics in January 2025 strengthened concerns about fluoride exposure.
Researchers examined 74 studies involving fluoride exposure and children’s intelligence.
Their meta-analysis identified an inverse association between fluoride exposure and IQ scores, meaning higher measured exposure was associated with lower scores.
Among studies using individual urinary fluoride measurements, each additional milligram per liter was associated with an estimated 1.63-point reduction in IQ.
The researchers also identified associations at lower exposure measurements in some analyses.
However, the evidence was less certain when exposure was estimated solely from drinking water containing less than 1.5 milligrams of fluoride per liter.
Urinary fluoride concentrations measure exposure differently from drinking water concentrations, and the two figures should not be treated as interchangeable.
The study did not demonstrate that every child consuming fluoridated municipal water will experience cognitive harm. It also did not establish a precise neurological risk at the standard American fluoridation concentration.
What it did establish was a sufficiently consistent association across multiple studies to warrant continued investigation.
For communities considering whether to continue fluoridation, those findings are difficult to dismiss as merely speculative.
Research During Pregnancy Raises Additional Questions
Concerns about neurological development are not limited to studies of school-aged children.
In 2019, researchers published a Canadian study in JAMA Pediatrics examining maternal fluoride exposure during pregnancy and subsequent childhood intelligence.
The researchers evaluated mothers and children from Canadian communities, including areas with fluoridated drinking water.
They reported an association between higher maternal fluoride exposure and lower IQ scores in offspring, although results varied depending on the exposure measure and the child’s sex.
The observational study could not prove that fluoride caused the differences.
Nevertheless, its findings raised questions about whether developing children could be particularly sensitive to fluoride exposure before birth.
Together with subsequent reviews, the study contributed to a broader scientific discussion about fluoride exposure during pregnancy and early childhood.
A Federal Judge Ruled Against Fluoridation — Then an Appeals Court Intervened
Scientific concerns eventually became the subject of federal litigation.
In September 2024, U.S. District Judge Edward Chen ruled that fluoridation at 0.7 milligrams per liter presented an unreasonable risk under the Toxic Substances Control Act and directed the Environmental Protection Agency to initiate regulatory action.
The ruling attracted attention because it addressed the concentration recommended for American municipal drinking water systems, rather than only the higher concentrations examined in many earlier studies.
However, the legal record changed in May 2026.
The Ninth Circuit Court of Appeals vacated the district court’s ruling, finding procedural error in how the lower court handled the litigation, and remanded the case.
The appellate decision did not resolve the underlying scientific dispute about fluoride safety.
The original district court finding therefore cannot be represented as a currently controlling determination that fluoridation at 0.7 milligrams per liter is legally unsafe.
The case nevertheless demonstrates how the issue has moved beyond academic journals into federal regulatory and judicial proceedings.
Are the Dental Benefits Still What They Once Were?
Fluoridation supporters emphasize its effectiveness in preventing tooth decay.
The Centers for Disease Control and Prevention and the American Dental Association have historically promoted community fluoridation as a public-health measure, particularly for populations with limited access to dental care.
Yet the estimated benefits of fluoridation have also been reconsidered.
In October 2024, the independent research organization Cochrane published an updated review examining the effects of adding fluoride to drinking water.
Researchers reviewed evidence from 157 studies and concluded that fluoridation’s dental benefits appear smaller in modern populations than they were before fluoride toothpaste became widely available.
This does not mean fluoridation provides no benefit.
It does raise a legitimate question about whether policies established in the 1940s should be reassessed in light of changes in dental hygiene, fluoride availability, and contemporary scientific evidence.
Today, fluoride is available through toothpaste, professional dental treatments, and other products.
Unlike municipal fluoridation, many of these methods allow individuals to make choices about their use with guidance from dental professionals.
The remaining question is whether the additional population-wide benefit of fluoridated water sufficiently outweighs any potential risks.
Why Elkton’s Decision Matters
For Elkton, the debate is not purely theoretical.
Municipal water fluoridation exposes residents through a shared public utility, rather than through a product each individual chooses to purchase.
Water systems control fluoride concentrations, but residents consume different quantities of water and may receive additional fluoride through food, dental products, or other sources.
The town’s consideration of removing fluoride creates an opportunity to examine the local program in detail.
Among the information residents may reasonably want are Elkton’s current fluoride monitoring results, the amount added during treatment, the natural fluoride concentration in its source water, and the annual cost of operating its fluoridation equipment.
Residents may also want to know whether local dental-health professionals have been consulted and how the town has evaluated recent federal research.
Those facts would help establish whether Elkton’s circumstances differ from those of communities examined in national studies.
A Decision Requiring More Than Tradition
Water fluoridation was introduced during an era when tooth decay represented a significant public-health problem and preventive dental care was less widely available.
The researchers and institutions that promoted it believed they were addressing a serious health concern.
But policies adopted decades ago are not beyond reconsideration.
The evidence concerning higher fluoride exposure and children’s neurological development deserves careful examination. So do the remaining uncertainties about lower concentrations and the potential dental consequences of discontinuing fluoridation.
Elkton’s consideration of removing fluoride provides an opportunity to examine those issues publicly rather than allowing an established practice to continue without periodic review.
Residents deserve access to the town’s water-quality data, an explanation of its existing fluoridation program, and a clear account of the evidence informing any decision.
The central question is whether a policy developed more than eight decades ago continues to provide a favorable balance of benefits and risks under present-day conditions.
For something as essential as drinking water, that question deserves a thorough answer.
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