Fluoride has been added to U.S. public drinking water since 1945. For most of that time, it was treated as settled public health policy. That's changing. Recent research, a federal court ruling, and shifting positions from government agencies have renewed a legitimate debate about whether the benefits of water fluoridation outweigh the risks, particularly for children.

This post lays out the concern, what the research says, and where the uncertainty genuinely lies.

Why Fluoride Is Added to Drinking Water

The goal has always been dental health. Drinking water fluoridated at the level recommended by the U.S. Public Health Service reduces dental cavities by approximately 25% in children and adults. The current recommended level in the U.S. is 0.7 milligrams per liter (mg/L).

Eighty years of community water fluoridation at optimal levels has been considered safe and effective at reducing tooth decay. The CDC, American Dental Association, and American Academy of Pediatrics all continue to endorse it.

The dental benefit is real. That's the starting point for an honest conversation about fluoride safety and water fluoridation risks.

Why the Water Fluoridation Debate Has Intensified

The NTP Systematic Review (2024)

The National Toxicology Program's 2024 systematic review concluded, with moderate confidence, that higher estimated fluoride exposures, including drinking water fluoride concentrations exceeding the World Health Organization guideline of 1.5 mg/L, are consistently associated with lower IQ in children.

That 1.5 mg/L threshold matters. It is more than double the U.S. recommended level of 0.7 mg/L.

The JAMA Pediatrics Meta-Analysis (January 2025)

A meta-analysis published in JAMA Pediatrics synthesized more than 70 epidemiological studies across 12 countries and reported an inverse association between fluoride exposure and children's IQ scores.

Importantly, the NTP review was designed to evaluate total fluoride exposure from all sources, not fluoridated drinking water alone. The authors noted there were insufficient data to determine whether the lower level of 0.7 mg/L currently recommended for U.S. community water systems poses the same risk.

The Federal Court Ruling (September 2024)

U.S. District Judge Edward Chen ruled that the current maximum fluoride concentration of 0.7 mg/L poses an unreasonable risk to public health, especially to children's IQs, and ordered the EPA to take regulatory action under the Toxic Substances Control Act.

The EPA has since committed to conducting a thorough review of these findings and additional peer-reviewed studies to prepare an updated health effects assessment for fluoride.

What the Fluoride Research Does and Doesn't Say

What it does say:

• A consistent association exists between higher fluoride exposure and lower IQ in children, primarily at levels above 1.5 mg/L.
• The association is drawn from a large and growing body of epidemiological studies across multiple countries.
• Some high-quality studies show inverse associations even at lower exposure levels, though the evidence there is less conclusive.

What it doesn't say:

• The biological mechanism connecting fluoride and IQ has not been established.
• Causation has not been proven. The studies show correlation.
• The research does not establish that U.S. tap water at 0.7 mg/L causes cognitive harm, though that question has not been definitively answered.

The dental side of the equation:

A 2024 Cochrane review found that fluoride added to water was less effective at preventing cavities compared to studies done before 1975, attributed in part to the widespread use of fluoride toothpaste. Communities that have ended water fluoridation have seen notable increases in childhood cavity rates.

Removing fluoride from water is not a risk-free decision either.

Where Fluoride Regulation Stands Right Now

This is an active and unresolved policy debate. The EPA is conducting an accelerated review of public health risks from fluoride in drinking water, while decisions on whether to fluoridate drinking water have historically been made at the state or local level.

Utah became the first state to ban water fluoridation in 2025. Several other communities are weighing similar decisions.

Frequently Asked Questions About Fluoride in Drinking Water

Is fluoride in drinking water safe?

At the U.S. recommended level of 0.7 mg/L, fluoride in drinking water has been endorsed by the CDC, ADA, and American Academy of Pediatrics for its dental health benefits. A 2024 NTP review found an association between higher exposures and lower IQ in children, primarily above 1.5 mg/L.

Does fluoride lower IQ in children?

A 2025 meta-analysis in JAMA Pediatrics found an inverse association between fluoride exposure and children's IQ scores across more than 70 studies. The association is strongest at concentrations above 1.5 mg/L. Causation has not been established.

What did the 2024 NTP fluoride report conclude?

The National Toxicology Program concluded, with moderate confidence, that higher fluoride exposures, particularly above the WHO guideline of 1.5 mg/L, are consistently associated with lower IQ in children.

Does a water filter remove fluoride?

Yes. Reverse osmosis filtration systems are effective at removing fluoride from drinking water. Activated alumina filters also reduce fluoride levels. Standard carbon block filters, such as most pitcher filters, do not remove fluoride.

Why is fluoride added to drinking water?

Fluoride has been added to U.S. public drinking water since 1945 to reduce tooth decay. Community water fluoridation at optimal levels reduces cavities by approximately 25% in children and adults.

What to Do with This Information

This is a case where the science is genuinely in motion. The concern about fluoride health effects, particularly for children at elevated exposures, is backed by credible, peer-reviewed research. The concern about removing fluoride from water, particularly for lower-income communities without consistent access to dental care, is also backed by real evidence.

If you want to reduce your family's fluoride intake from tap water while the research continues to develop, reverse osmosis filtration is an effective option. View our water filtration options.

That is a reasonable, low-risk step. It is also worth talking to your dentist about fluoride exposure and your family's individual dental health needs before making changes.

Sources

• National Toxicology Program. NTP Monograph on Fluoride Exposure and Neurodevelopment and Cognition: A Systematic Review. August 2024.
• Taylor KW, et al. Fluoride Exposure and Children's IQ Scores: A Systematic Review and Meta-Analysis. JAMA Pediatrics. March 2025.
• Iheozor-Ejiofor Z, et al. Water Fluoridation for the Prevention of Dental Cavities. Cochrane Database of Systematic Reviews. October 2024.
• U.S. EPA. Review of Science on Fluoride in Drinking Water: Preliminary Assessment Plan and Literature Survey. 2025.
• Centers for Disease Control and Prevention. Community Water Fluoridation.
• Boehmer TJ, et al. Community Water Fluoridation Levels to Promote Effectiveness and Safety in Oral Health. MMWR. June 2023.