“On January 20, the Trump White House will advise all US water systems to remove fluoride from public water,” Kennedy wrote on X. “Fluoride is an industrial waste linked to arthritis, bone fractures, bone cancer, IQ loss, disorders of neurodevelopment, and thyroid disease.”

Kennedy went on to refer to a decision last month in which a federal judge ordered the Environmental Protection Agency to begin the process of strengthening fluoride regulations. The decision, he said, showed the agency “improperly approved this dangerous neurotoxin.”

Long known as a skeptic of vaccines and other public health measures, Kennedy supported Trump when he suspended his own presidential campaign in August. He has been touted as a potential adviser to Trump on health policy – an alarming prospect for critics who say his positions are dangerous.

Trump said NBC News that he had not discussed the subject with Kennedy, but that the plan “sounds good to me.”

“You know, it’s possible,” he said.

Fluoride was introduced into water systems in the 1940s as a means of promoting dental health. Since then, many local water suppliers have continually adjusted fluoride levels, citing its remineralizing effects on tooth enamel. In 2022, approximately 72% of the US population—more than 209 million people—were served by public fluoridated water sources, according to the Centers for Disease Control and Prevention.

Although fluoride is a byproduct of certain industrial processes, it is a natural compound that is present in both fresh water and plants, as well as in certain foods such as tea leaves and many seafood. It is found in most common toothpastes as well as many brands of bottled water.

Many public health organizations and advocacy groups, incl American Dental Associationhas long advocated fluoridation of drinking water supplies. The introduction and widespread adoption of the practice has been hailed as one of the greatest public health achievements of the 20th century by the CDC, who credit fluoride with a documented decrease in cavities and other dental problems.

Public health officials have adjusted fluoride guidelines in the past. In 2015, the CDC recommended that water suppliers lower fluoride levels, noting that Americans now get fluoride from a variety of sources other than drinking water, such as toothpaste.

Fluoride has been the subject of medical concerns – many of them unfounded – since it was first introduced. Conspiracy theorists in the 1950s claimed that fluoridation was a communist plot to destroy American public health – a notion famously parodied in Stanley Kubrick’s 1964 film “Dr. Strange love.”

More recently, critics have cited studies examining the effects of excessive levels of fluoride intake, which can cause dental fluorosisa cosmetic condition in young children that can make the teeth appear mottled. A more serious effect is skeletal fluorosis, which causes weaker bones and joint pain—although the condition is rare in the United States. It is much more common in parts of India and China, where groundwater is naturally rich in fluoride.

A federal report released this year linked higher levels of fluoride intake — more than 1.5 milligrams of fluoride per liter of water — with slightly lower IQ in children. In September, a federal judge orderly EPA to investigate the effects of fluoride on children’s intellectual development, although he acknowledged that the evidence for the levels commonly added to US drinking water is unclear.

As of 2015, the recommended level of fluoridation in the United States is 0.7 milligrams per liter—a level maintained by the Massachusetts Water Resources Authority. EPA standards prohibit water systems from containing more than 4 milligrams of fluoride per liter.

There is little or no evidence linking community water fluoridation with other adverse health effects, such as increased risk of cancer, heart disease or serious neurological disorders, According to the CDC.

Despite widespread adoption of fluoridation since the 1940s, some areas have decided against it.

Data on regions that do not practice fluoridation are mixed. Many developed countries do not practice water fluoridation, including most of Europe – although some countries, such as Germany and Switzerland, have alternative processes such as fluoridated salt and fluoridated milk.

Hawaii is the only state with without municipal fluoridation; — although the state ranks as one of the worst states for oral health in the nation. Other studies have suggested a worsening of tooth decay rates in municipalities that had fluoridation and later banned it, such as Juneau, Alaska.

Camilo Fonseca can be contacted at [email protected]. Follow X @fonseca_esq and on Instagram @camilo_fonseca.reports.