Water Fluoridation: Which Countries Add Fluoride, and What the Science Actually Says

Water fluoridation, the practice of adding controlled amounts of fluoride to a public water supply to reduce tooth decay, has been one of the most debated public health measures of the past eight decades. First introduced in Grand Rapids, Michigan in 1945, the practice has since been adopted in parts of 25 countries. Yet the vast majority of the world’s nations, including nearly all of Europe, have chosen not to fluoridate.

In 2024 and 2025, the debate entered a new phase. A federal court ruled for the first time that fluoridation at U.S.-recommended levels poses an “unreasonable risk” to children’s neurodevelopment. The National Toxicology Program published its long-awaited report on fluoride and cognition. And a major meta-analysis in JAMA Pediatrics synthesized more than 70 studies on fluoride and children’s IQ. Then, in May 2026, an appeals court overturned the landmark ruling on procedural grounds, without disputing the underlying science.

This article examines the full picture: the history, the global data on who fluoridates and who does not, the dental benefits, the neurotoxicity concerns, and the current state of the science.

Which countries fluoridate their water, and is it safe? Only about 25 countries add fluoride to public water, and roughly 5 percent of the world drinks it, with the U.S. recommending 0.7 mg/L. Fluoride clearly reduces tooth decay, but recent reviews linking higher exposure to lower childhood IQ have intensified debate over whether the dental benefit justifies water fluoridation at all.

What Is Water Fluoridation?

Water fluoridation is the practice of adding a small, controlled amount of fluoride to public drinking water to strengthen teeth and reduce cavities. Fluoride is a naturally occurring mineral found in water, soil, rocks, and certain foods. At low concentrations, fluoride strengthens tooth enamel by promoting remineralization, the process by which minerals are redeposited in enamel after being removed by acids produced by bacteria in dental plaque. This is the basis for fluoride’s use in toothpaste, mouth rinses, and water fluoridation.

Community water fluoridation (CWF) adjusts the fluoride concentration in a public water supply to a target level considered optimal for dental health. In the United States, the U.S. Public Health Service has recommended 0.7 milligrams per liter (mg/L) since 2015, down from a previous range of 0.7–1.2 mg/L. The World Health Organization (WHO) sets an upper guideline of 1.5 mg/L for naturally occurring fluoride in drinking water, a limit designed to protect against dental and skeletal fluorosis, the visible damage caused by excessive fluoride intake.

It is important to distinguish between deliberate fluoridation and naturally occurring fluoride. In parts of China, India, Iran, and East Africa, groundwater fluoride levels can reach 5–48 mg/L, far above any recommended range. In these regions, the public health challenge is not adding fluoride but removing it. The health effects documented in these high-fluoride areas, skeletal fluorosis, severe dental fluorosis, and possible neurological effects, are the subject of many of the studies cited in the fluoride-IQ debate, which makes the question of dose highly relevant.

When Did Water Fluoridation Begin?

It began in the United States in 1945, after dentists noticed that people in areas with naturally higher fluoride had far fewer cavities. The story of water fluoridation begins with a dental mystery in the early 1900s. In 1901, a young dentist named Frederick McKay arrived in Colorado Springs and noticed that many long-time residents had severe brown staining on their teeth, a condition he eventually called “Colorado brown stain” and that is now known as dental fluorosis. Intriguingly, the stained teeth were also highly resistant to cavities.

Over the next three decades, McKay and other researchers traced the cause to naturally occurring fluoride in the local water supply. By the 1930s, H. Trendley Dean at the U.S. Public Health Service had identified an apparent “sweet spot”, around 1 part per million (ppm) of fluoride in water, where cavity rates dropped significantly without widespread severe staining.

In January 1945, Grand Rapids, Michigan became the first city in the world to deliberately add fluoride to its public water supply. The nearby city of Muskegon served as the unfluoridated control. Within 11 years, the Grand Rapids study reported that cavity rates in children had dropped by more than 60%. By the mid-1950s, fluoridation had spread to cities across the United States, and by the 1960s it was being adopted in parts of Australia, Canada, New Zealand, Ireland, and the United Kingdom.

Which Countries Fluoridate Their Water?

Only about 25 countries fluoridate public water, reaching roughly 5 percent of the world; the practice is most common in the United States and a few English-speaking nations, while most of Europe does not. Despite its long history, water fluoridation remains uncommon worldwide. According to data compiled by the British Fluoridation Society (2020 audit) and the American Dental Association (2025), approximately 380 million people in 25 countries receive water fluoridated by adjustment, roughly 5% of the global population. An additional 57 million people drink naturally fluoridated water at concentrations near the recommended range.

The United States accounts for more than half of all people worldwide who drink fluoridated water. About 73% of the U.S. population served by community water systems, approximately 209 million people as of 2022, receives fluoridated water, according to the CDC.

Why Most of Europe Does Not Fluoridate

One of the most striking facts about water fluoridation is that 97% of Western Europe does not practice it. Of the 38 OECD member countries, only 10 have any fluoridation program at all, and four of those 10 fluoridate less than 15% of their population. Excluding the United States, just 7% of the OECD population drinks artificially fluoridated water.

European countries that have discontinued fluoridation include Germany (stopped in 1971), Sweden (1971), the Netherlands (1976), Finland (1993), and Japan (which reduced fluoridation to near-zero levels by the 1970s). The reasons vary by country but generally fall into three categories: ethical objections to mass medication without individual consent, the widespread availability of fluoride toothpaste rendering systemic fluoridation unnecessary, and precautionary concerns about long-term health effects at the population level.

Several of these countries have instead adopted fluoridated salt or fluoridated milk programs, which allow individuals to choose their level of exposure. Switzerland, for example, fluoridates about 80% of its domestic table salt. France, Germany, and Costa Rica have similar programs.

Notably, tooth decay rates in non-fluoridating European countries are comparable to or lower than those in fluoridating countries. WHO data on the DMFT index (Decayed, Missing, and Filled Teeth) in 12-year-olds show that Denmark, the Netherlands, Germany, and Sweden, none of which fluoridate, have DMFT scores similar to or better than those of the United States, Australia, and Ireland. This observation does not prove that fluoridation is ineffective, since many factors influence tooth decay (diet, dental care access, use of fluoride toothpaste, sugar consumption). But it does complicate the argument that fluoridation is indispensable.

Countries That Stopped Fluoridation

Israel provides a particularly instructive case. The country mandated water fluoridation in 2002 but halted the practice in 2014 following a Supreme Court ruling. A 2025 retrospective study published in a peer-reviewed dental journal analyzed digital dental records of 12-year-old Israeli children from 2014 to 2022 and found that after fluoridation ended, the caries experience (measured by the Missing-and-Filled component of DMFT) increased significantly, especially in low-socioeconomic-status communities, where children in non-fluoridated areas had more than double the caries experience of children in high-SES communities.

This finding illustrates an argument frequently made by fluoridation supporters: while middle- and upper-income populations can compensate through dental visits, fluoride toothpaste, and dietary choices, low-income communities benefit most from fluoridation because it provides a baseline level of protection that does not depend on individual behavior or ability to pay.

What Are the Dental Benefits of Fluoridation?

Fluoridation reduces tooth decay by around 25 percent across income levels, according to the CDC, and especially helps people with limited access to dental care. The CDC estimates that community water fluoridation reduces tooth decay by approximately 25% over a person’s lifetime. A 2015 Cochrane Review, considered one of the highest levels of evidence in medicine, analyzed available studies and concluded that fluoridation reduces tooth decay in children, though it noted that most of the evidence came from studies conducted before fluoride toothpaste was widely available, and that the quality of evidence was generally low.

A 2025 study from São Paulo, Brazil provides more recent data. Researchers tracked dental caries in 12-year-olds from 1986 to 2023 and found that the mean DMFT index declined by 76.7% over the period, from 6.47 in 1986 to 1.51 in 2023, during which the city maintained fluoridation at concentrations predominantly between 0.55 and 0.94 mg/L.

An Australian study in the journal Public Health Reports found that children in areas with negligible fluoride in water had 1.34 times the odds of having at least one decayed, missing, or filled deciduous tooth compared to children in optimally fluoridated areas.

Is Water Fluoridation Safe? The Neurotoxicity Question

At U.S. levels the safety picture is debated: a 2024 federal review and 2025 analysis linked higher fluoride exposure, mostly above U.S. levels, to lower childhood IQ, while evidence at U.S. concentrations remains limited. The safety question has evolved significantly in recent years. For decades, major health organizations maintained that fluoridation at recommended levels posed no health risks other than mild dental fluorosis (faint white spots on teeth that are generally considered cosmetic). This consensus has been challenged, though not overturned, by a growing body of epidemiological research linking fluoride exposure to neurodevelopmental effects in children.

The NTP Report (August 2024)

The National Toxicology Program (NTP) spent eight years developing a systematic review of the evidence on fluoride exposure and neurodevelopment. The project was contentious from the start. NTP’s first two drafts were reviewed by the National Academies of Sciences, Engineering, and Medicine (NASEM), which twice rejected them, citing “deficiencies” and directing NTP to remove its original claim that fluoride is a “presumed” neurodevelopmental hazard.

The final report, published in August 2024, concluded “with moderate confidence” that higher fluoride exposure, defined as concentrations exceeding the WHO guideline of 1.5 mg/L, is “consistently associated with lower IQ in children.” Crucially, the NTP stated that its report “was not designed to evaluate” community water fluoridation at 0.7 mg/L. The NASEM had explicitly advised that the monograph “cannot be used to draw any conclusions” about exposures at typical U.S. fluoridation levels.

The JAMA Pediatrics Meta-Analysis (January 2025)

In January 2025, scientists from the National Institute of Environmental Health Sciences published a companion meta-analysis in JAMA Pediatrics (Taylor et al., 2025). The analysis pooled data from 74 epidemiological studies involving more than 17,000 children across 12 countries and reported a statistically significant inverse association between fluoride exposure and children’s IQ scores, an estimated 1.63-point IQ drop per 1 mg/L increase in water fluoride concentration.

The journal published the study alongside two editorials representing opposite sides of the debate. One editorial called the findings significant; the other, written by University of Iowa fluoride expert Steven Levy, cautioned that the analysis was “deeply flawed” and that the results were driven by low-quality studies from countries with fluoride levels far above those used in U.S. fluoridation.

A subsequent response by the NTP authors, published in Annals of Global Health (PMID: 41393310) in December 2025, addressed the criticisms directly. The authors noted that the inverse association persisted when analyses were restricted to only high-quality studies and across subgroups defined by sex, age, country, and exposure metric, and that some high-quality studies observed associations at fluoride levels below 1.5 mg/L.

The Federal Court Ruling (September 2024)

While the scientific debate continued, a federal court was making history. In September 2024, Senior Judge Edward Chen of the U.S. District Court for the Northern District of California ruled that fluoridation at the U.S. Public Health Service’s recommended level of 0.7 mg/L “poses an unreasonable risk of reduced IQ in children.” He ordered the EPA to initiate regulatory action under the Toxic Substances Control Act (TSCA).

The ruling was extraordinary for several reasons. It was the first time a citizen petition under TSCA had succeeded in court. It was the first time a judge, rather than EPA, determined that a chemical poses an “unreasonable risk.” And it directly contradicted the position of the CDC, ADA, and EPA, all of which maintain that fluoridation is safe and effective.

The Appeals Court Reversal (May 2026)

In May 2026, the Ninth Circuit Court of Appeals overturned Judge Chen’s ruling. However, the reversal was based entirely on procedural grounds, the appeals court found that Chen had overstepped by pausing the trial to wait for the NTP report, which constituted “an abuse of discretion” and a departure from the “party-presentation principle.” The EPA did not challenge the factual merits of Chen’s scientific findings, and the appeals court did not address them.

This means the scientific questions raised in the trial remain open. No court has ruled that fluoridation is safe; a court has ruled that the process by which it was found to be risky was procedurally improper.

Dental Fluorosis: The Visible Trade-Off

Dental fluorosis is the most visible and well-documented side effect of fluoride exposure in early childhood. It occurs when children ingest excess fluoride during the years when permanent teeth are forming (typically before age 8). Mild fluorosis appears as faint white streaks or spots on the enamel and is generally considered cosmetic. Moderate to severe fluorosis can cause brown staining, pitting, and structural damage to tooth surfaces.

According to a national survey cited by the ADA and the CDC, approximately 60% of U.S. children and adolescents show some degree of dental fluorosis, though the vast majority of cases are classified as very mild or mild. Critics argue that the high prevalence of fluorosis is itself evidence that total fluoride exposure from all sources (water, toothpaste, food, beverages) exceeds what the developing body can safely handle.

Pros and Cons of Water Fluoridation

Water Fluoridation by State: Where Fluoridation Rates Vary

Fluoridation rates vary significantly within the United States. According to the CDC’s My Water’s Fluoride database, states with the highest fluoridation coverage include Kentucky (~100%), Minnesota (~99%), and Illinois (~98%). States with the lowest rates include Hawaii (~12%), New Jersey (~22%), and Oregon (~23%). These differences reflect local decision-making, in most states, the decision to fluoridate is made at the city or county level, not by the state government.

Several U.S. cities have voted to end fluoridation in recent years, including Portland (Oregon), which rejected fluoridation in a 2013 public referendum by a margin of 61% to 39%. Portland remains the largest U.S. city without a fluoridation program.

How Can I Reduce My Fluoride Exposure?

Reverse-osmosis filters and distillation remove most fluoride from drinking water, while standard carbon pitcher filters do not. For individuals who wish to reduce their fluoride intake from drinking water, several filtration methods are effective:

Reverse osmosis (RO) systems remove approximately 90–95% of fluoride. These can be installed under the kitchen sink or as whole-house systems. RO is the most widely recommended method for fluoride reduction.

Activated alumina filters are specifically designed to adsorb fluoride from water. They are effective at reducing fluoride to below 0.1 mg/L when properly maintained.

Distillation removes virtually all fluoride along with other dissolved solids. Countertop water distillers are available for home use.

Standard carbon filters, including those found in most pitcher-style filters like Brita, do not remove fluoride. This is a common misconception.

Bottled water labeled “purified” or “distilled” typically contains very low fluoride levels. Bottled spring water, however, varies widely and may contain naturally occurring fluoride; the FDA does not require fluoride content to be listed on bottled water labels unless fluoride has been added.

The NIEHS scientists who authored the 2025 JAMA Pediatrics meta-analysis offered practical advice for concerned parents: they may wish to “replace tap water with low-fluoride bottled water, like purified water, and limit exposure from other sources such as dental products or black tea.” Black and green tea plants accumulate fluoride from the soil, and brewed tea can contain 1–6 mg/L of fluoride depending on the type and brewing time.

The 2024 NTP Report and 2025 JAMA Pediatrics Meta-Analysis

Two publications in 2024–2025 significantly shifted the scientific debate around fluoride and neurodevelopment.

NTP Monograph (August 2024)

After nearly eight years of work, internal review, peer review, and a National Academies evaluation, the National Toxicology Program (NTP) released its final systematic review in August 2024. The monograph examined 74 epidemiological studies conducted across 10 countries (Canada, China, Denmark, India, Iran, Mexico, Pakistan, New Zealand, Spain, and Taiwan) and concluded, with moderate confidence, that higher fluoride exposure is associated with lower IQ in children (NTP Monograph 08, 2024).

The NTP defined “higher exposure” as fluoride levels above 1.5 mg/L, twice the U.S. community water fluoridation target of 0.7 mg/L. Twenty-two of the 74 studies were rated as high quality (low risk of bias). The monograph explicitly noted that it did not evaluate community water fluoridation at the U.S. recommended level, though it acknowledged that the evidence raised questions about exposures at lower levels as well.

The report’s release was itself a story. The NTP began the review in 2016 and completed a draft by 2020, but internal disagreements within the National Institutes of Health and pressure from dental health organizations delayed publication for years. A 2023 court order in the TSCA lawsuit (see below) ultimately forced the release of the final version.

JAMA Pediatrics Meta-Analysis (January 2025)

The same NTP scientists published a detailed meta-analysis in JAMA Pediatrics in January 2025, analyzing the 74 epidemiological studies from the monograph. The analysis found a statistically significant inverse association between fluoride exposure and children’s IQ scores. Among the 22 high-quality studies, the association was consistent: higher fluoride exposure was linked to lower IQ, with effect sizes that, while individually small, were comparable to those seen with low-level lead exposure (Taylor et al., Annals of Global Health, 2025).

The TSCA Court Ruling (September 2024)

One month after the NTP monograph’s release, a federal judge in California ruled in TSCA v. EPA that water fluoridation at the U.S. Public Health Service’s recommended level of 0.7 mg/L posed an “unreasonable risk” of reducing IQ in children. The court ordered the EPA to take regulatory action under the Toxic Substances Control Act, at minimum, to formally review the evidence for neurotoxicity. This was the first time a U.S. court had issued such a ruling on water fluoridation.

The ruling does not ban fluoridation. It requires the EPA to assess the risk and respond, which could range from new regulations to an advisory to a determination that the current level is acceptable. As of mid-2026, the EPA had not yet issued its formal response, and the ruling is under appeal.

What These Developments Mean

It is important to understand what the NTP report says and what it does not say. It does not conclude that water fluoridation at 0.7 mg/L causes IQ loss. It concludes that higher exposures (>1.5 mg/L) are associated with lower IQ, and that the evidence at levels closer to 0.7 mg/L is inconclusive but warrants attention. The distinction between association and causation, and between high-exposure regions (some with natural fluoride above 4 mg/L) and U.S. community water systems (targeted at 0.7 mg/L), remains the central point of scientific disagreement.

What has changed is the institutional validation. Before 2024, fluoride neurotoxicity research was largely conducted by independent academic groups and was often dismissed by dental and public health organizations as inconclusive. The NTP, a federal agency within the National Institutes of Health, has now concluded that the association is real at higher exposure levels, and a federal court has ruled that the risk at U.S. levels is “unreasonable.” These are new facts on the ground that will shape the fluoridation debate for years to come.

Fluoride Sources Beyond Drinking Water

Public discussion of fluoride tends to focus on water, but total fluoride exposure comes from multiple sources that are often overlooked.

Dental products. Fluoride toothpaste (typically 1,000–1,500 ppm fluoride) is the single most common source of topical fluoride exposure. Children under six who swallow toothpaste during brushing may ingest 0.3–0.8 mg per brushing session, a non-trivial amount relative to their body weight. The CDC recommends a “smear” of toothpaste for children under 3 and a “pea-sized” amount for children 3–6 to minimize ingestion.

Processed foods and beverages. Any food or beverage manufactured with fluoridated water contains fluoride. Commercial grape juices, teas (the tea plant naturally accumulates fluoride from soil), and processed foods made with fluoridated municipal water all contribute to total daily intake. A 2019 USDA analysis estimated that dietary fluoride from food and beverages accounts for 0.3–0.6 mg/day for adults in fluoridated communities.

Pesticide residues. Cryolite (sodium hexafluoroaluminate), a fluoride-containing pesticide, is permitted on grapes and several other crops in the United States. Residues contribute a small but measurable amount to dietary fluoride intake, particularly for consumers of conventionally grown grapes and raisins.

Naturally occurring fluoride. Fluoride is present in groundwater worldwide at highly variable concentrations. In parts of India, China, and East Africa, natural fluoride levels exceed 4–10 mg/L, far above any intentional fluoridation level, causing endemic skeletal and dental fluorosis. The WHO’s guideline limit for fluoride in drinking water (1.5 mg/L) was set primarily to address these naturally high-fluoride regions.

The total fluoride exposure for an individual depends on their water source, diet, dental product use, and age. This complexity is one reason the fluoridation debate resists simple answers: a person drinking unfluoridated well water and using fluoride toothpaste has a very different exposure profile from a child drinking fluoridated tap water in a region with fluoride-containing pesticide residues on local produce.

The Economics of Water Fluoridation

The economic argument for water fluoridation has traditionally been one of its strongest selling points. Adding fluoride to municipal water costs roughly sh.50–.50 per person per year for most water systems, a fraction of a penny per day. The CDC has estimated that for every dollar invested in community water fluoridation, approximately 8 is saved in dental treatment costs, making it one of the most cost-effective public health interventions available.

This cost-effectiveness calculation rests on several assumptions: that fluoridation prevents a meaningful number of cavities that would otherwise require fillings, crowns, or extractions; that the dental treatment costs avoided exceed the infrastructure, chemical, and monitoring costs of the fluoridation program; and that alternative methods of delivering fluoride (toothpaste, dental varnishes, mouth rinses) would not achieve the same results at comparable cost.

For large water systems serving hundreds of thousands of people, the per-person cost is minimal and the economic case is strong. For small, rural water systems, however, the calculus is different. The fixed costs of fluoridation equipment and monitoring represent a larger per-person burden, and some small communities have discontinued fluoridation on cost grounds alone, a decision that is sometimes characterized as anti-fluoride activism but is often straightforwardly financial.

The Equity Argument

Supporters of fluoridation frequently cite its equity benefits. Topical fluoride (toothpaste, professional treatments) requires individual action, access to dental care, and in many cases out-of-pocket cost. Water fluoridation delivers fluoride passively to everyone in a community, including populations that may have limited access to dental care, low-income families, the elderly, rural residents, and communities of color who face well-documented disparities in oral health. In this framing, fluoridation is a social determinant of health intervention: it narrows the gap between those who can access dental care and those who cannot.

Opponents counter that the equity argument does not justify involuntary medication of an entire population, particularly when the risk-benefit ratio may differ for infants, pregnant women, and people with kidney disease who process fluoride less efficiently. This tension between population-level benefit and individual consent is at the heart of the fluoridation debate and is unlikely to be resolved by science alone, it is fundamentally a values question about the role of government in public health.

What Changed in the Cost-Benefit Calculation

The NTP report and TSCA ruling have introduced a new variable into the fluoridation cost-benefit equation: a potential cognitive cost. If fluoride exposure at levels near the U.S. target does reduce IQ even slightly, the economic impact of that reduction, calculated across an entire population in terms of lifetime earnings, educational attainment, and economic productivity, could theoretically dwarf the dental cost savings. Researchers on both sides recognize this possibility. The disagreement is over whether the evidence supports that scenario at 0.7 mg/L or only at higher concentrations.

Until the EPA completes its formal risk assessment (ordered by the 2024 court ruling), this question will remain unresolved. In the meantime, individual communities continue to make their own decisions, informed by a scientific evidence base that is richer and more contested than at any point in the 80-year history of water fluoridation.

The Bottom Line

Water fluoridation remains a polarizing issue precisely because reasonable people can weigh the same evidence and reach different conclusions. The dental benefits are real, fluoridation reduces cavities, and the effect is largest in populations with the least access to dental care. The neurotoxicity concern is also real, a growing body of evidence, including a major government report and a large meta-analysis in a top-tier pediatric journal, has found associations between fluoride exposure and lower IQ in children, though the relevance of these findings to exposure at 0.7 mg/L remains actively debated.

What is clear is that the scientific landscape has shifted. The NTP report, the JAMA Pediatrics meta-analysis, and the federal court ruling have collectively moved the fluoride-IQ question from the fringe to the mainstream of public health discourse. Whether that leads to policy changes in the United States or elsewhere remains to be seen.

Frequently Asked Questions

Which countries add fluoride to their water?

About 25 countries fluoridate public water, reaching roughly 5 percent of the world’s population. The practice is most common in the United States, Australia, New Zealand, Ireland, and Canada. Most of continental Europe does not fluoridate water, relying instead on fluoride toothpaste and sometimes fluoridated salt, yet has comparable tooth-decay rates.

Is fluoridated water safe to drink?

At the U.S. level of 0.7 mg/L, decades of use support dental benefits, but the safety picture is debated. A 2024 federal review and 2025 meta-analysis linked higher fluoride exposure, mostly above U.S. levels, to lower childhood IQ. Evidence at U.S. concentrations is limited and mixed, so the debate centers on dose.

Does water fluoridation prevent cavities?

Yes. The CDC estimates fluoridation reduces tooth decay by about 25 percent across income levels, and it especially benefits people with limited access to dental care. A 2015 Cochrane review confirmed a reduction in decay, though it noted the quality of evidence was low and that much of it predates widespread fluoride toothpaste.

How can I remove fluoride from my water?

Reverse-osmosis systems and distillation remove most fluoride, while standard carbon filters, including many pitcher filters, do not. People who filter out fluoride should still get dental protection from fluoride toothpaste. Those mixing infant formula may choose low-fluoride water to reduce the risk of dental fluorosis.

What is dental fluorosis?

Dental fluorosis is a usually cosmetic change in tooth enamel, ranging from faint white spots to staining, caused by too much fluoride while teeth are forming in childhood. Mild forms are common and harmless, but the fact that a large share of U.S. children show some fluorosis suggests total fluoride exposure may be higher than needed.

Why do most European countries not fluoridate water?

Many European countries decided against water fluoridation on grounds of individual consent and preference for targeted measures, using fluoride toothpaste and sometimes fluoridated salt instead. Their tooth-decay rates have still fallen substantially, largely thanks to toothpaste, which is one argument critics use against the need for water fluoridation.

References

1. National Toxicology Program (NTP). NTP Monograph on the State of the Science Concerning Fluoride Exposure and Neurodevelopment and Cognition. NTP Monograph 08. August 2024. ntp.niehs.nih.gov
2. Taylor KW, Eftim SE, Sibrizzi CA, et al. Fluoride Exposure and Children’s IQ Scores: A Systematic Review and Meta-Analysis. JAMA Pediatrics. 2025;179(3):254–267. doi:10.1001/jamapediatrics.2024.5542
3. Taylor KW, et al. Addressing Critiques of the Evidence Linking Fluoride and Children’s IQ. Annals of Global Health. 2025;91(1):83. PMID: 41393310
4. Food & Water Watch v. EPA, No. 17-cv-02162-EMC (N.D. Cal. Sept. 24, 2024). Findings of Fact and Conclusions of Law
5. Ninth Circuit Court of Appeals reversal (May 22, 2026). E&E News / Politico
6. U.S. Centers for Disease Control and Prevention. Community Water Fluoridation. cdc.gov/fluoridation
7. American Dental Association. Fluoridation Facts, 2025 Edition. ADA e-Bookshelf
8. British Fluoridation Society. One in a Million: The Extent of Water Fluoridation (2020 audit). Referenced in ADA Fluoridation Facts 2025.
9. World Health Organization. Guidelines for Drinking-water Quality, 4th edition, Chapter 12: Fluoride. WHO
10. Fluoride Action Network. Water Fluoridation Status in OECD Nations. fluoridealert.org
11. Fluoride Action Network. WHO Tooth Decay Rates, Fluoridated vs. Non-Fluoridated Countries. fluoridealert.org
12. Iheozor-Ejiofor Z, et al. Water Fluoridation for the Prevention of Dental Caries. Cochrane Database of Systematic Reviews. 2015. doi:10.1002/14651858.CD010856.pub2
13. Dental Caries and Fluorosis After 40 Years of Community Water Fluoridation in São Paulo, Brazil (2025). PMC
14. Effect of Community Water Fluoridation Cessation on Dental Caries in 12-Year-Old Israeli Children (2025). PMC
15. Do LG, Spencer AJ. Community Effectiveness of Public Water Fluoridation in Reducing Children’s Dental Disease. Public Health Reports. 2007. PMC
16. National Toxicology Program. NTP Monograph on the State of the Science Concerning Fluoride Exposure and Neurodevelopment and Cognition: A Systematic Review. NTP Monograph 08. 2024. PubMed
17. Taylor KW, Eftim SE, Sibrizzi CA, et al. Fluoride Exposure and Children’s IQ Scores: A Systematic Review and Meta-Analysis. JAMA Pediatr. 2025;179(3):282–292.
18. Taylor KW, et al. Addressing Critiques of the Evidence Linking Fluoride and Children’s IQ. Annals of Global Health. 2025. doi:10.5334/aogh.4853

Last updated: September 26, 2026