Maria Arozamena, Illustrations Editor

It was called one of the greatest public health achievements of the 20th century. The fluoridation of water has been linked to oral health improvements for many Americans, as it provides an equitable and cost-effective system of fluoride delivery to communities across the country. 

However, before the 2024 presidential election, Robert F. Kennedy Jr. posted on social media that if up to him, he would advise all U.S. water systems to remove fluoride from public water systems. And now, with President-elect Donald Trump picking Kennedy to be the next secretary of the Department of Health and Human Services, Kennedy’s beliefs highlight the growing debate of whether or not fluoride should be in U.S. water.

Some health professionals and scientists believe that the complete removal of fluoridation in water is an idea based in misguided science that could cause more harm than good. However, others, citing evidence that suggests that fluoridated water does have legitimate harmful outcomes, believe that some changes need to be made.

“The public benefits of fluoride and fluoridation of drinking water are clear and well-established,” Dr. Nicole Deziel, associate professor of epidemiology at the School of Public Health, wrote to the News. “[However] there is some evidence of links between fluoride overexposure and neurological and cognitive effects. While not yet conclusive, this evidence combined with the availability of fluoride in other products, has prompted some reexamination of whether the recommended fluoride concentrations and the maximum limits in drinking water should be lowered to maximize public health benefits.”

The history and benefits of water fluoridation

U.S. water fluoridation was implemented to help prevent tooth cavities and dental caries, an infectious bacterial disease in a tooth’s enamel surface that can lead to the loss of tooth structure. This results in crippling pain and bacterial infection, forcing the loss of tooth function and tooth extraction. During the first half of the 20th century, dental caries were prevalent across the country. 

Fluorosis, or the extreme mineralization of tooth enamel caused by excessive fluoride ingestion, was identified as a prevalent oral condition in America as well. However, the Dental Hygiene Unit at the National Institutes of Health discovered that dental caries among children was lower in areas with more fluoride in community water supplies.

“In 1945, cities like Grand Rapids, Michigan, began to conduct field studies for dental caries prevention by increasing the fluoride levels in water,” Dr. Ashley Malin, an assistant professor of epidemiology at the University of Florida, told the News.

Surveys conducted over 13 to 15 years found that caries were reduced by 50 percent to 70 percent among children in communities with fluoridated water. This study also inspired a recommended range of fluoride concentration in water from 0.7 to 1.2 ppm. Cities across the United States in the second half of the 1900s adopted the public health measure as a way to prevent dental caries, leading to a decline in their prevalence. Additionally, fluoride delivery began to take the form of oral health care products like toothpaste, gels and mouth rinses around this time.

According to the CDC, with the introduction of fluoridated water, tooth decay has decreased by at least 40 percent in children and tooth loss by at least 40 percent in adults. Additionally, school children in communities with fluoridated water have 2.25 fewer decayed teeth compared to children who do not have access to fluoridated water. 

According to Deziel, the enhancement of oral health leads to cardiovascular benefits as well, since poor oral health is linked to heart diseases caused by bacteria spreading through the bloodstream. Additionally, children who undergo tooth decay experience pain, have difficulty concentrating in class and experience social stigma. Fluoridation of water helps prevent these problems. 

“Fluoride reduces the ability of the bacteria, a major cause of cavities to make acid,” Dr. Vasilis Vasiliou, chair of the environmental health sciences department at the School of Public Health, told the News. 

Fluoride also reverses or stops tooth decay by placing minerals back into the teeth. This makes the teeth more resistant to acid and stronger.

According to Vasiliou, fluoridation of water is important because it improves oral health care for all, including those who find it hard to access dental care. Some fluoridated products like toothpaste and dental care are not accessible to everyone, but public water systems can reach everyone in communities with fluoridated water. This allows for the reduction of disparities in dental insurance and access to dental care.

The ineffectiveness and possible risks of water fluoridation

According to Malin, water fluoridation’s implementation led to one to two teeth saved on average. After 1975, however, the dental health benefits of water fluoridation diminished, as now there’s only an average of a quarter of a tooth being saved due to fluoridation. 

“When fluoride was first implemented decades ago, its benefits were profound,” Deziel told the News. “The current benefits are still present, but are more modest, due to the presence of fluoride in toothpaste and other oral hygiene products. However, good dental care is not accessible and affordable to all.”

Additionally, high levels of fluoride can have dangerous outcomes. According to Vasiliou, this can happen from the combination of using dental products and drinking water from a private well that has elevated levels of fluoride. This leads to dental fluorosis, which leads to weaker enamel, brittle teeth and other severe dental issues.

Additionally, studies are coming out that showcase at least some correlation between elevated levels of fluoride in water and slowed neurological development. A study that Malin helped conduct this year also suggested that fluoride exposure could cause harm to the brain development of a fetus during pregnancy. This could be in the form of reduced IQ or brain damage.

“They determined a moderate confidence that fluoride exposure is consistently associated with reduced child IQ at a minimum for those living in regions with water fluoride concentrations of 1.5 milligrams per liter or higher,” Malin told the News.

The CDC recommends 0.7 mg per liter of fluoride in drinking water.

According to Malin, there hasn’t been enough evidence that proves these neurological effects occur below 1.5 mg/L. However, the NTP also didn’t completely rule out the risk of neurological development harms at lower levels due to a lack of information. 

According to Vassiliou, the CDC, the American Dental Association and the American Academy of Pediatrics all support water fluoridation. The CDC has said they haven’t found convincing evidence that has linked community water fluoridation with any potential adverse health effects or disorders, including in neurological development but also immune disorders, bone fractures or allergic reactions.

However, according to Vasiliou, the CDC hasn’t provided a public statement related to the NTP 2024 study of slow neurological development in children.

“There was also a recent ruling in a federal trial where the EPA [U.S. Environmental Protection Agency]  was being sued by a consumer group to end fluoridation because the plaintiffs were concerned that it was negatively impacting child neurodevelopment,” Malin said. “The EPA has been ordered to mitigate that risk and create more of a margin of safety between the level of 1.5 milligrams per liter that’s consistently associated with reduced child IQ and the current recommended level of 0.7 mg/L.”

However, the judge noted that it’s unclear whether or not the recommended level of 0.7 mg/L causes slowed neurological development; he also didn’t specify the exact steps that the EPA needed to take.

Kennedy’s impact

Kennedy believes water fluoridation has various possible dangerous health effects, citing not only neurological development but also arthritis, bone cancer and IQ loss. And although organizations like the American Academy of Pediatrics found no valid evidence to support his claims that fluoride causes possible health harms outside of neurological development, Kennedy believes that there should be no fluoridation in water in America. In an interview with NBC, President-elect Donald Trump said “It sounds okay to me,” referring to Kennedy’s wish to remove fluoride from water.

However, according to Deziel, the decision to fluoridate water is a local one. Elected officials or the public, through open voting, set the policy of water fluoridation. And not everyone needs to fluoridate water. 

“In part, some areas may have relatively high background naturally occurring levels of fluoride in the water already and therefore do not need to supplement it,” Deziel told the News. In other places, voters have decided against fluoridation.

Though Kennedy can’t control local laws, his words have a significant impact. Some cities like Winter Haven, Florida, are already deciding to remove fluoride from water, according to Malin; one commissioner on the panel has based his claims on Kennedy’s statement on the issue. 

Avenues for Resolution

Though Vasiliou says there are possible dangers of fluoride, he believes that the benefits significantly outweigh the harms. Reducing the risk of slowed neurological development by lowering the target amount of fluoride and other actions is up for discussion. However to remove fluoride entirely from drinking water could reignite disparities in oral health across the country. 

According to Malin, the issue of water fluoridation inspires some disagreement between medical professionals and some environmental professionals like herself. She believes that environmental public health is now starting to become more concerned about the systemic adverse health effects of fluoride exposure. But, she doesn’t see water fluoridation as a political issue and believes it shouldn’t be. 

“I don’t think it needs to be politicized,” Malin said. “I think this is more of a human issue, and one that people should really focus on the state of the existing science in forming their opinions about. Hopefully, as science evolves, we all can come and work together to determine what the best course of action for the most people may be.”

Though most of Kennedy’s claims about the negative health effects of fluoride in water are unsubstantiated, Malin believes that this is a legitimate area of focus and discussion that he’s bringing to the table. And this doesn’t have to mean the complete removal of fluoride from water. This could instead translate to more dedicated research on the harms of fluoridated water at the recommended levels so there’s more information and evidence available for policymakers to use. 

According to Deziel, the Connecticut Department of Public Health, or CTDPH, requires public water systems serving 20,000 or more people to add fluoride to drinking water to a fluoride level of 0.55 to 0.85 ppm.