History and Controversy of Fluoride in Drinking Water

Drinking water from the faucet.

Water fluoridation, the controlled addition of fluoride to public water supplies, has been a cornerstone of public health initiatives aimed at reducing dental decay. Initiated in the United States in 1945, it has since been adopted in numerous countries, though not without controversy. In light of Robert F. Kennedy Jr.’s nomination for the Secretary of the Department of Health and Human Services ahead of the second administration for incoming-President Donald Trump, both critics and supporters have pointed to Kennedy’s pronounced opposition to the fluoridation of water. Safety and health experts now share concerns about what this will mean for the future of public health. 

Kennedy and his supporters question its safety and purpose in drinking water, while opponents fear for the potential health concerns if the practice is stopped upon Trump’s first weeks in office. However, this spotlight on fluoride is among a slew of arguments and issues dating back over 100 years.

While the practice of water fluoridation began in Grand Rapids, Michigan, in 1945, research on fluoride’s effects on teeth began in 1901 in Colorado Springs. There, dental researchers found high rates of fluorosis—a condition resulting in teeth discoloration and deformation—named “Colorado Brown Stain.” This was in great part due to the high rates of fluoride in the city’s drinking water. In understanding the cause of the condition, it was found that the teeth of those with fluorosis were incredibly resistant to decay. 

Years later, researchers found that controlled amounts of fluoride (up to 1 part per million) in drinking water did not result in enamel fluorosis for most people and only mild enamel fluorosis in a small percentage of people. After fluoridation started In Grand Rapids, Michigan, a study of over 30,000 school children over the course of 15 years found that the rates of caries—crumbling of the tooth bone—had dropped by more than 60%. Today, according to the National Institute of Dental and Craniofacial Research, 73% of Americans, or around 200 million people in the U.S., have access to fluoridated drinking water.

As history seems to repeat itself, many objectors in the first iterations of fluoridation refused to allow what they’ve dubbed “rat poison” in their drinking water, claiming that the government should not intervene in the issue. And while fluoride is, in fact, a primary ingredient in rat poison, public health experts and scientists elaborate on the importance of dosage.

Recently, a 2024 report by the National Toxicology Program indicated a possible association between elevated fluoride levels and lower IQs in children, though the evidence remains inconclusive. More specifically, the report itself reviewed over 500 pieces of peer-reviewed literature that evaluated high levels of fluoride exposure. Fluoride critics elevated the study as dogma and solid truth, saying that future generations are put at risk with continuous exposure.

However, dental organizations have questioned the validity of the report, saying that misinterpretations of the report are dangerous in the court of public opinion.Other back-and-forth debates on the practice include the idea of whether water fluoridation counts as nonconsensual “mass medication,” citing the Food and Drug Administration’s labeling of fluoride as a drug rather than as a nutrient. Some opponents, particularly during the Cold War, went as far as saying the fluoridation of water was a communist plot against the American people. Others point to how European countries have stopped the practice of fluoridation—however, this varies from country to country as many still utilize artificial fluoride in drinking water. Reassessment in the fluoride levels is being considered as fights pop up across the United States.

By Lois Angelo