He made reference to a September ruling from a judge that ordered the EPA to address fluoridation concerns.

RFK Jr. Says Trump Would Push to End Adding Fluoride to Drinking Water

He made reference to a September ruling from a judge that ordered the EPA to address fluoridation concerns.

“Fluoride is an industrial waste associated with arthritis, bone fractures, bone cancer, IQ loss, neurodevelopmental disorders, and thyroid disease,” Kennedy wrote on X.

Since 1945, U.S. municipalities have added fluoride to tap water in a bid to combat tooth decay. The U.S. Public Health Service recommends that water systems have a fluoride level of 0.7 milligrams per liter.

A report issued early this year by the National Toxicology Program, an agency within the U.S. Department of Health and Human Services, found that high levels of fluoride in other countries could be tied to lower IQ levels in children. The agency found that drinking water levels with 1.5 milligrams of fluoride per liter could pose a problem in children.

For the past five decades, the recommended upper range has been 1.2 milligrams per liter. The World Health Organization has set a safe limit for fluoride in drinking water of 1.5 milligrams.

U.S. District Judge Edward Chen wrote that while it isn’t certain that the amount of fluoride typically recommended in the United States can lower the IQ of children, recent research shows the compound could pose a risk.

“If there is an insufficient margin, then the chemical poses a risk,” the judge wrote. “Simply put, the risk to health at exposure levels in United States drinking water is sufficiently high to trigger regulatory response by the EPA” under federal law, according to Chen.

He said that “scientific literature in the record provides a high level of certainty that a hazard is present” and that “fluoride is associated with reduced IQ.”

Earlier this year, Kennedy suspended his independent presidential bid and backed Trump. The former president often makes mention of the endorsement from Kennedy, the scion of a Democratic dynasty and the son of former Attorney General Robert Kennedy and nephew of President John F. Kennedy.