Researchers from Tulane University linked high fluoride levels in wells to cognitive deficits in children in Ethiopia, finding more impairment with greater exposure. The study adds to concerns over fluoride’s neurotoxicity, especially for early brain development.
Children with chronic exposure to high levels of fluoride in drinking water made more errors on drawing and cognitive tests, according to a new pilot study by researchers at Tulane University.
The study, which linked fluoride exposure and cognitive impairment, was published in the November-December issue of the peer-reviewed Neurotoxicology and Teratology journal.
Lead author Tewodros Godebo, Ph.D., assistant professor of environmental health sciences at Tulane University School of Public Health and Tropical Medicine, told Tulane News that the testing underlying their study “affirmed a clear association between high fluoride and cognitive impairment.”
“These results add to the growing concern about the potential neurotoxic effects of fluoride, especially during early brain development and childhood,” Godebo said. He said more epidemiological studies should be conducted to validate the findings of his team’s work.
For the study, researchers recruited 74 children ages 5-14 from demographically and ethnically similar rural Ethiopian farming communities with varying levels of natural fluoride in their community wells, ranging from 0.4 to 15.5 mg/L.
The U.S. Public Health Service recommends 0.7 milligrams per liter (mg/L) as the “optimal level” for water fluoridation and the World Health Organization recommends that fluoride levels be kept below 1.5 mg/L.
The children were tested for fluoride exposure and their cognitive performances were measured using two tests.
One test assessed the children’s abilities to draw common objects. The other used the Cambridge Neuropsychological Test Automated Battery, or CANTAB test, to assess memory and learning.
The researchers didn’t analyze IQ. Instead, they used tests designed to identify different markers of cognitive impairment and found that the higher the levels of fluoride exposure, the worse children performed on both tests and that in the CANTAB tests, the total number of errors became “markedly stronger” as the tasks became more difficult.
“This well-conducted study by a team of U.S. scientists is the latest in a long series of studies showing that fluoride is a neurotoxicant that can cause cognitive impairment in children,” Michael Connett, attorney for the plaintiffs in a lawsuit challenging the U.S. Environmental Protection Agency (EPA) to end water fluoridation in the U.S.
“At this point, it’s no longer a question of, does fluoride damage the brain? Does fluoride lower IQ?” Connett told The Defender. “It’s a question of, at what dose? How does that dose vary with innate susceptibility among the population?”
He added, “The obliviousness of public health officials to this clear and present danger is becoming intolerable.
Fluoride exposure is receiving more scrutiny from scientists and the public in part because of a lawsuit brought in 2017 by Food and Water Watch, Fluoride Action Network and others alleging water fluoridation violates the EPA’s Toxic Substances Control Act and that fluoride is neurotoxic and lowers children’s IQ.
Numerous recent scientific studies have linked fluoride exposure to cognitive impairment in children, including reduced IQ. Although some studies have not found similar associations.
Epidemiological studies have also shown specific links to reduced IQ and other cognitive effects on children in areas with high endemic levels of fluoride in drinking water supplies.
The authors of the Tulane study called for more research on the topic, particularly for studies to establish at what level fluoride is neurotoxic, as well as the effects of low levels of fluoride in drinking water.
PERCEPTION RESET 