Fluoride in drinking water poses enough risk to merit new EPA action, judge says
A federal judge has ordered the U.S. Environmental Protection Agency to further regulate fluoride in drinking water because high levels could pose a risk to the intellectual development of children.
U.S. District Judge Edward Chen said that it’s not certain that the amount of fluoride typically added to water is causing lower IQ in kids, but that mounting research points to the possibly of an unreasonable risk. He ordered the EPA to take steps to lower that risk, but didn’t say what those measures should be.
It’s the first time a federal judge has made a determination about the neurodevelopmental risks to children from the recommended U.S. water fluoride level, said Ashley Malin, a University of Florida researcher who has studied the effect of higher fluoride in pregnant women.
She called it “the most historic ruling in the U.S. fluoridation debate that we’ve ever seen.”
The judge’s ruling is another striking dissent to a practice that has been hailed as one of the greatest public health achievements of the last century. Fluoride strengthens teeth and reduces cavities by replacing minerals lost during normal wear and tear, according to the U.S. Centers for Disease Control and Prevention.
Elevated prenatal exposure to fluoride was associated with increased risk of neurobehavioral problems in 3-year-olds, according to a study of children in Los Angeles.
In August, a federal agency determined “with moderate confidence” that there is a link between higher levels of fluoride exposure and lower IQ in kids. The National Toxicology Program based its conclusion on studies involving fluoride levels at about twice the recommended limit.
The EPA argued as a defendant in a lawsuit that it wasn’t clear what impact lower levels of fluoride exposure may have.
The agency is required to ensure there is a margin between the hazard and exposure levels. And “if there is an insufficient margin, then the chemical poses a risk,” Chen wrote in last week’s ruling.
“Simply put, the risk to health at exposure levels in United States drinking water is sufficiently high to trigger regulatory response by the EPA,” he wrote.
EPA spokesperson Jeff Landis said the agency was reviewing the decision but offered no further comment.
In 1950, federal officials endorsed water fluoridation to prevent tooth decay. They continued to promote it even after fluoride toothpaste brands hit the market several years later.
Fluoride can come from a number of sources, but drinking water is the main source for Americans, researchers say. Nearly two-thirds of the U.S. population currently gets fluoridated drinking water, according to CDC data.
Since 2015, federal health officials have recommended a fluoridation level of 0.7 milligrams per liter of water. For five decades before that, the recommended upper range was 1.2 milligrams. The World Health Organization has set a safe limit for fluoride in drinking water of 1.5 milligrams per liter.
Separately, the EPA has a long-standing requirement that water systems cannot have more than 4 milligrams of fluoride per liter of water — a standard designed to prevent skeletal fluorosis, a potentially crippling disorder that causes weaker bones, stiffness and pain.
But in the last two decades, studies have suggested a different problem: a link between fluoride and brain development. Researchers wondered about the impact on fetuses and very young children who might ingest water with baby formula. Studies in animals showed fluoride could impact neurochemistry cell function in brain regions responsible for learning, memory, executive function and behavior.
The court case, argued in U.S. District Court in San Francisco, started in 2017. The lead plaintiff was Food & Water Watch, a not-for-profit environmental advocacy organization. Chen paused the proceedings in 2020 to await the results of the National Toxicology Program report, and heard arguments earlier this year.
“In our view, the only effective way to eliminate the risk from adding fluoride chemicals to water is to stop adding them,” said Michael Connett, the plaintiffs’ lead attorney, in an email last week.
Stobbe writes for the Associated Press. The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Science and Educational Media Group. The AP is solely responsible for all content.
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