With the nomination of Robert F. Kennedy Jr. as health secretary, a formerly fringe opinion suddenly gets wide attention.
At an aging water treatment plant north of New York City, the fluoride solution was leaking from a pump. It was intended to be added to the drinking water piped down from the Catskills, to strengthen teeth and prevent dental decay. But instead it was dripping onto the ground, where it had soon eaten through the concrete.
That leak, in 2012, was followed by repairs and upgrades that took more than a decade. For much of that time, the town of Yorktown, in northern Westchester County, drank unfluoridated water. By the time the new fluoridation system was up and running in August 2024, the town supervisor, Ed Lachterman, had detected a shift in public opinion.
He had grown accustomed to hearing from people who insisted that Yorktown’s water remain fluoridated. “It was, ‘fluoride, fluoride, fluoride,’” he recalled. But in the intervening years, his constituents seemed far more wary, voicing concerns about fluoridated water’s effect on the brain or framing it as an issue of autonomy — “my body, my choice,” he recalled.
A month after resuming fluoridation, Mr. Lachterman reversed course, suspending it in September. He cited an unexpected development: A federal judge in San Francisco had just concluded that fluoride, long known to be toxic at high levels, “poses an unreasonable risk of reduced I.Q. in children” even in amounts close to what is typically added to the nation’s drinking water. The judge ordered the Environmental Protection Agency to do something about it.
His ruling followed a report released in August by the National Toxicology Program, part of the U.S. Department of Health and Human Services, that concluded “with moderate confidence” that higher fluoride exposures “are consistently associated with lower I.Q. in children.”
The judicial ruling was a surprising development in the nation’s running debate over the virtues and perils of adding fluoride to our water supply, a controversy that over 80 years has veered across a lot of territory — from public health to conspiracy theories. The debate had seemed to be settling down. A quarter-century ago, the Centers for Disease Control and Prevention had declared water fluoridation to be one of the 20th century’s greatest public health achievements, pointing to the dramatic decline in cavities and tooth decay.