Introduction
What is Water Fluoridation?
Community water fluoridation involves modifying the fluoride content in public drinking water to a level that helps prevent cavities. The recommended level, set by the U.S. Public Health Service, is 0.7 parts per million (ppm), equivalent to 0.7 milligrams of fluoride per liter of water, a concentration that has been shown to reduce tooth decay without causing tooth staining.
The Science Behind Water Fluoridation
A 2007 study found that fluoride, when present in small amounts in drinking water, becomes part of the saliva and helps constantly bathe the teeth. It promotes remineralization of early tooth decay and inhibits acid production by harmful bacteria, making teeth more resistant to decay over time. Researchers have also found that adults living in fluoridated communities have significantly fewer cavities than those in non-fluoridated areas. Community water fluoridation prevents approximately 27-35 percent of coronal caries, or cavities on tooth surfaces, in adults.
According to the Centers for Disease Control and Prevention (CDC), in communities with at least 1,000 residents every dollar invested in water fluoridation yields an estimated $20 in return. While larger communities tend to see even greater savings, smaller ones also benefit financially. On average, individuals in areas with fluoridated water save about $32 annually by reducing the need for cavity-related dental treatments.
History of Water Fluoridation in the United States
The history of water fluoridation in the United States reflects decades of public health progress. The discovery of fluoride’s effect on teeth began in 1901, when Dr. Frederick McKay noticed unusually low cavity rates and brown-stained enamel in Colorado Springs. He later linked this “mottled enamel” (now called dental fluorosis) to high fluoride levels in drinking water. In 1931, Dr. H. Trendley, Dean of the U.S. Public Health Service, confirmed fluoride’s role in both fluorosis and cavity prevention. By 1945, Grand Rapids, Michigan, became the first city to officially add fluoride to its water supply in a controlled public health effort.
In the following decades, fluoridation rapidly expanded. In the 1950s and 1960s, fluoride toothpaste became available on the market, and millions gained access to fluoridated water. In the 1970s and 1980s, new federal laws (like the Safe Drinking Water Act) affirmed that fluoridation decisions remained at the state level, rather than being mandated federally. In 2008, over 64 percent of Americans had access to fluoridated tap water. By 2012, three-quarters of Americans received fluoridated water through public systems. In 2020, the U.S. Department of Health and Human Services (HHS) raised its Healthy People 2030 goal to ensure optimal fluoride levels for 77.1 percent of the population.
Mechanics of Water Fluoridation: How Does it Work?
In most United States water treatment facilities, water fluoridation is carried out community-wide by precisely calibrating chemical feed systems to keep fluoride concentrations at the U.S. Public Health Service’s recommended amount of 0.7 milligrams per liter (mg/L). This amount was determined to be the ideal amount to reduce cavities and increase overall oral health. Fluoride is not present naturally at these optimal concentrations in a vast majority of all United States public water supplies, so it is constantly controlled and monitored to maintain the correct amount.
The chemicals used in the fluoridation process are selected for their safety and solubility in water. The three most common ones used in the United States are fluorosilic acid, sodium fluorosilicate, and sodium fluoride. Larger treatment plants usually tend to use fluorosilic acid because it comes in liquid form, and it can be easily distributed into the water stream through metering pumps. In smaller systems, sodium fluoride, which is a solid, is widely used. Even though sodium fluoride is more costly because its handling is more labor-intensive, it’s preferred in small systems because less of it is needed. Even though there is a difference in additives from place to place, they are all regulated by the American Water Works Association.
In the treatment process, fluoride is added after the water has been disinfected and filtered before entering the clearwell. The order ensures that the water is free from anything that could interfere with the fluoride mixing, ensuring the evenness of a fluoride blend. The typical order of a water plant is coagulation, flocculation, sedimentation, filtration, chlorination, fluoridation, corrosion control, storage, and lastly distribution.
Fluoride is dosed out by flow-paced systems. Simply, that just means the rate the chemical is added is proportional to the amount of water being processed overall. Operators behind the scenes also conduct manual tests to double-check that the digital analyzers are correct to maintain the right concentration. A lot of care is taken in making sure safety and overall public health standards are upheld. Fluoridation is a modern cornerstone in modern public health infrastructure. This approach has been refined over decades to deliver safe and effective fluoride levels.
State Versus Federal Water Fluoridation Policy
Many states, including Arkansas, Florida, Kentucky, and Utah, have recently proposed bills in their state houses and senates that seek to reduce or eliminate water fluoridation. Utah became the first state to fully ban water fluoridation on March 27, 2025, according to the American Dental Association. Other states, like Connecticut and New Jersey, have further strengthened their water fluoridation standards. Some of these states even struck down bills that would remove water fluoridation completely.
For the last 80 years, all states have had water fluoridation policies that closely followed federal recommendations and regulations. According to dentists in the United States, distrust of fluoridation in the last few years was fueled by a broader distrust of medical professionals borne out of the COVID-19 pandemic. This new level of distrust caused misinformation regarding water fluoridation to spread, and now many state lawmakers are feeding into the distrust of their constituents and proposing state-level bills to remove fluoride from drinking water altogether.
According to an issue brief written by the Kaiser Family Foundation (KFF), the federal government does not have the power to control legislation regarding water fluoridation. However, the federal government can make recommendations on fluoridation, release reports regarding the benefits and drawbacks of fluoridation, and provide guidance on best practices for water fluoridation. Furthermore, the Safe Drinking Water Act allows the EPA to set and enforce standards for maximum allowable fluoridation levels in all United States water sources. This means that the fluoridation in any water supply is not allowed to exceed the standard set by the EPA. If they do not follow these standards, the individuals responsible for the water source or those responsible for polluting it can be fined or prosecuted by the EPA.
Misinformation Surrounding Water Fluoridation
Spread of Fluoride Misinformation
Misinformation surrounding water fluoridation began to gain traction in the 1950s, when Cold War tensions fueled distrust toward government programs. The John Birch Society, an extremist right-wing group with an anti-communist ideology, historically promoted conspiracy theories claiming that adding fluoride to public water was part of a dangerous communist plot. Although these claims were disproven, they continue to influence some of the controversy today. With the rise of the internet and social media in the 2000s, misinformation circulated beyond those small activist groups. Modern anti-fluoridation thinking reframed the argument to be around themes of personal autonomy and government overreach, which made it more appealing to a broader political spectrum. This shift transformed the controversy of fluoridation into an issue not confined to just one party, allowing skepticism to spread even more than it used to.
Current Perceived Issues with Water Fluoridation
One of the most prominent critics, Secretary of Health and Human Services Robert F. Kennedy (RFK) Jr., has called fluoride an “industrial waste” and claims it to be associated with conditions such as arthritis, bone cancer, and neurodevelopmental disorders. Critics also argue that fluoride mainly aims to benefit dental, and argue its need to be consumed through drinking water rather than used in targeted dental treatments. According to public health data, long-term exposure to fluoride levels above the recommended limit can lead to skeletal fluorosis, a condition that weakens bones and causes joint pain. Excessive fluoride can also cause dental fluorosis, leading to white lines on tooth enamel.
Another point raised by opponents is the idea that adding fluoride to public water limits personal choice. They believe that individuals should decide whether or not they ingest fluoride, rather than having it “forced on them.” Advocates of this idea often suggest targeted alternatives, such as fluoride toothpaste, for those who want the dental benefits.
Key Figures in the Anti-Fluoridation Movement
Several notable figures have played a role in the anti-fluoridation debate. In Ohio, State Representative Levi Dean co-sponsored House Bill 182, which would prohibit public water systems from adding fluoride. Influenced by Health Secretary Kennedy’s skepticism and the suggestion that fluoride may be linked to lower IQ in children, he argued that the bill preserves individual choice and avoids forcing fluoride consumption. U.S. District Judge Edward Chen recently ruled that there is enough evidence of potential harm to warrant further investigation, despite it being unclear whether typical fluoride levels in United States drinking water causes a decline in IQ in children. The ruling directed the Environmental Protection Agency to take additional action in evaluating and regulating fluoride in public water. Moreover, researchers, such as Dr. Ashley Malin, an assistant professor in the Department of Epidemiology at the University of Florida, argues that the science has identified the fluoridation of water as a hazard to child IQ. This controversy has become a central talking point for all fields of authority.
The Health Impacts of Fluoridation
Fluoride is often used in the form of toothpaste and mouthwash. It is known to strengthen bone and tooth enamel, which can help prevent cavities. Preventing cavities can also reduce the risk of other health issues, including cardiovascular problems. When fluoridation of drinking water started in the 1940s, it was found to be an effective and cheap solution to reduce cavities. In medically underserved areas with no fluoridated water supply, children are more susceptible to untreated tooth decay that impacts their overall well-being. For children who lack access to dental insurance, water fluoridation is a viable and equitable solution. Today, 200 million Americans receive fluoridated water from a public water system. For individuals at high risk of dental problems, there is clear evidence that combining fluoridated water with oral fluoride products offers enhanced protection against tooth decay.
However, there are some skeptics of water fluoridation. When there is excessive fluoride, adverse effects include harm to teeth and bones via fluorosis, which can cause discoloration or damage, as well as bone fractures. The most recent analysis of clinical data from 2015 to 2016 showed that approximately two-thirds of children aged six and above had some level of mild dental fluorosis. Furthermore, the data highlights that getting mild fluorosis does not negatively affect oral health-related quality of life. A potential correlation has also been observed between low to moderate fluoride exposure and lower IQ in children.
Additionally, there is evidence of cognitive and neurological issues with high doses of fluoride. Currently, the federal government recommends a fluoride concentration of 0.7 mg/L; however, the regulatory limit is 4 mg/L. For transparency,the CDC maintains public records that list the fluoride levels in tap water by county.
Tooth decay is the most common disease among American children aged 1 to 4, making it a critical public health concern. If untreated, it can cause unnecessary pain and difficulty concentrating, leading to a decreased quality of life. As mentioned earlier, the return on investment for communities with water fluoridation where the population exceeds 1000 people is $20 saved for every dollar invested. In Colorado, researchers analyzed 172 public water systems that served at least 1000 people or more, and found that fluoride exposure saved an average of $60 per person annually.
The Equity Stakes of Fluoridation Rollbacks
As outlined in previous sections, fluoridation offers measurable health benefits, especially for children at higher risk of cavities and related dental complications. However, fluoridation’s benefits are only realized if communities have reliable, safe access to treated water in the first place—a standard that remains unmet in various areas across the country. This gap highlights a broader issue of equitable access to clean water, which means ensuring that all individuals, regardless of income, race, or geography, can consistently obtain safe, affordable drinking water that supports basic health and well-being.
Unfortunately, this vision of equitable access to clean water has never come to fruition. Recent data from the Superfund Research Program at UC Berkeley links elevated exposure to water contaminants with low socioeconomic or minority racial status, reflecting decades of unequal environmental protections and underinvestment in infrastructure for systemically challenged areas. These inequities go largely unnoticed unless they become a crisis, as Flint, Michigan, did in 2014.
The Flint, Michigan crisis—where a predominantly Black and low-income community experienced widespread lead contamination after a crucial water source changed—remains the glaring example of inequality in water quality. Following the investigation, the CDC confirmed that Flint children had significantly higher blood lead levels following the water source change, displaying how mismanagement of public water can quickly transform into an irreversible public health emergency. Even following this tragedy, more than nine million lead water service lines remain in operation, disproportionately in lower-income areas. Native American and rural communities face similar clean water access disparities—a 2021 report by DigDeep and the U.S. Water Alliance found that Native American households are 19 times more likely to lack indoor plumbing than white households. This indicates that in certain regions, the issue extends beyond access to clean water, revealing a lack of access to water altogether.
Within this landscape, community water fluoridation functions as a uniquely low-cost, passive intervention that reduces oral health disparities without requiring out-of-pocket spending, dental insurance, or specialized public health literacy. Recent data from the CDC showed that untreated cavities are nearly three times more common among children ages two to five in low-income households (18 percent) compared to higher-income peers (7 percent). Given this correlation, removing fluoridation policies could widen this gap, raising both the prevalence of preventable dental disease and the financial burden of treatment for those most at-risk.
Extensive evidence supports the safety and efficacy of fluoride at the recommended concentration of 0.7 ppm. At these levels, no credible research links fluoridation to neurocognitive harm or adverse gut health effects, though it is important to note that these negative side effects can occur at higher ppm levels. The economic case for water fluoridation is equally strong, given that optimally fluoridated water saves an estimated $6.5 billion annually in dental treatment costs, yields a return of roughly $20 for every $1 invested, and reduces cavities by about 25%. These numbers translate to $32 in annual savings per person and fewer missed school or work days.
Ensuring equitable access to clean, fluoridated water is therefore not simply an infrastructure priority, but a matter of public health equity. Rolling back fluoridation would disproportionately harm communities already facing the steepest barriers to care, undermining decades of progress toward closing health gaps.
Conclusion and The Future of Water Fluoridation
Water fluoridation began as a science-based public health intervention but has, since its introduction, become a target of fearmongering and misinformation, leading to recent rollbacks. A historically cost-effective and equitable health policy now risks being dismantled—not because the science has changed, but because a shift in ideology threatens decades of evidence.
As shown throughout this brief, fluoridation has been proven to reduce tooth decay while also delivering strong economic outcomes that benefit individuals and communities of all sizes. However, decentralized authority of water fluoridation policies has resulted in inconsistent access, with some states bolstering their fluoridation policies while others move to eliminate them entirely. Furthermore, while moves to expand water fluoridation policy seem to be rooted in evidence, decisions to remove fluoride from water are largely charged by misinformation and conspiracy theories. In reality, credible research has proven that removing fluoride would increase preventable dental disease, especially among children, while worsening racial, geographic, and economic health disparities.
Historically, water policy has consisted of more than just contaminant removal; it should serve as a platform for proactive, evidence-based health interventions. Water fluoridation policy has long demonstrated that slight shifts in infrastructure can effectively reduce public health inequities at scale. Allowing fluoridation’s repeal directly threatens the dental health of affected communities and could also set a precedent for dismantling other proven public health measures. Defending fluoridation is therefore not only about protecting teeth—but about protecting trust in public health itself.