Hundreds of thousands of American children are drinking tap water that could lower their IQ, according to a shocking government report.
The paper, described as the most thorough of its kind, concluded that consuming large amounts of fluoride can harm brain development in young people.
Researchers found that drinking water with more than 1.5 milligrams of fluoride per liter was associated with a drop in IQ of up to five points.
This finding may be significant as more than 1.9 million people rely on water systems with fluoride levels above 1.5 mg, the report said.
The report, based on an analysis of previously published research, is the first time a federal agency has determined “with reasonable certainty” that there is a link between fluoride and IQ.
The map above shows estimated fluoride concentrations in community water systems between 2006 and 2011. It was published in 2023. Counties colored red have more than double the recommended fluoride level in their water
Fluoride has been added to the American drinking water supply for decades after research showed it can strengthen teeth and reduce cavities. It has long been considered one of the greatest public health achievements of the 20th century.
According to the CDC (Centers for Disease Control and Prevention), fluoridation saves $6.5 billion annually in dental treatment costs and reduces the number of cavities by as much as 25 percent.
But the new report is likely to raise alarm bells in dozens of counties in Illinois, Texas and New Mexico, where research has shown that fluoride levels in the water are particularly high.
Since 2015, the US has recommended that fluoride levels in drinking water not exceed 0.7 milligrams per liter.
According to the Environmental Protection Agency, fluoride levels should not exceed four milligrams per liter to prevent skeletal fluorosis, a potentially crippling condition that causes weak bones, stiffness and pain.
According to the World Health Organization, the safe limit is about 1.5 milligrams of fluoride per liter.
According to experts, fluoride easily enters the bloodstream when ingested and can then travel to the brain.
Previous animal studies have shown that fluoride can affect neurochemistry in brain areas related to learning, memory, executive function and behavior.
The new 324-page government report comes from the National Toxicology Program, part of the Department of Health and Human Services.
Several studies discussed in the report found that IQ was 2 to 5 points lower in children exposed to higher levels.
The team could not draw conclusions about the impact of fluoride at lower doses or about its effect on adults.
There has been controversy over fluoride in drinking water supplies for years, with hundreds of communities voting against its use (above is a campaign sign from Kennebunk, Maine)
The report confirms previous evidence linking fluoride to anxiety, mood problems and headaches in children as young as three years old.
Previous research has shown that pregnant women should limit their exposure to fluoride because the mineral can cross the placenta and reach the fetus.
The new report summarizes research from Canada, China, India, Iran, Pakistan and Mexico.
The conclusion was that drinking water with more than 1.5 milligrams of fluoride per liter was associated with lower IQ in children.
According to the report, more than 1.9 million people – or 0.6 percent of the U.S. population – rely on water systems with naturally occurring fluoride levels greater than 1.5 milligrams per liter.
It was not mentioned how many people use water systems to which artificial fluoride has been added and where concentrations are above this level.
The above image shows a woman filling a glass of water from the tap, amid concerns over the quality of the tap water (stock)
This 2020 map shows fluoride levels in untreated groundwater supplies. Fluoride is a naturally occurring mineral and is often already present in many water supplies. Areas marked with a yellow or red dot have more than twice the recommended level of fluoride in their groundwater
Fluoride is a mineral that occurs naturally in water and soil.
But about 80 years ago, scientists discovered that people whose water supply naturally contained more fluoride also had fewer cavities. They found that it replaced minerals in teeth that were lost to decay and wear.
This led to a push to get more Americans to use fluoride and add the mineral to the nation’s drinking water supplies.
Today, approximately 70 percent of American households have access to fluoridated drinking water.
This is much higher than in many comparable countries, including the United Kingdom (10 percent), Spain (10 percent) and Canada (40 percent).
The report comes as IQ scores in America are falling for the first time in a century.
A study from the University of Oregon and Northwestern analyzed the results of nearly 400,000 IQ tests conducted between 2006 and 2018, in a study published last year.
They did not give an exact decline, but did say that the largest decline occurred among people between the ages of 18 and 22 and among people with lower education.
The study only used data from before the Covid pandemic, meaning disruptions to education due to lockdowns may have further exacerbated the situation.
According to the anti-fluoride group Fluoride Action Network, more than 240 communities worldwide have removed fluoride from their drinking water since 2010.
Regina Barrett, 69, from a small town in North Carolina, is one of thousands of Americans who are unhappy with fluoride in their drinking water.
“Our water is cloudy and bubbly and looks milky,” said Ms. Barrett, who blames fluoride for the problems, according to KFF Health News“I don’t want fluoride in my nothing!”
Data from the National Population Review for the year 2024 shows that far more counties in the US fluoridate their water than any other country in the world.
The National Toxicology Program began investigating the impact of fluoride in drinking water in 2016.
There were earlier versions, but the final report was repeatedly blocked. At one point, a committee of experts said that the available research did not support the conclusion of an earlier version.
The American Dental Association, which advocates fluoride in water, was critical of earlier versions of the analysis but has not yet commented on the new report.
Rick Woychik, the program’s director, said in a statement: “Since fluoride is such an important topic for the public and public health officials, it was critical that we do everything we can to get the science right.”
Official limits were originally set to prevent skeletal fluorosis, but increasing research shows a link between higher fluoride levels and their impact on brain development.
Researchers wonder what impact water ingestion with bottle feeding might have on a developing fetus or very young children.
The Fluoride Action Network called this week’s report a “landmark,” saying it proved what many researchers have long suspected.