A US government report concludes that fluoride in drinking water, at more than double the recommended limit, affects a lower intelligence quotient in children. Intelligence tests are known as IQ for short.
The report, based on an analysis of previously published research, marks the first time a federal agency has determined “with moderate confidence” that there is a link between high levels of exposure to fluoride in drinking water and lower IQ. in children.
Although the report was not designed solely to assess the health effects of fluoride in drinking water, the result indicates the potential neurological risk from high levels of fluoride.
Fluoride strengthens teeth and fights tooth decay by replacing lost minerals, according to the US Centers for Disease Control and Prevention. The addition of low levels of fluoride to drinking water has long been considered one of the greatest public health achievements of the past century.
Dr. Ashley Malin is a researcher at the University of Florida who has studied the impact of high levels of fluoride on pregnant women and their children. She says this is the most rigorous report of its kind.
The long-awaited report, released Wednesday, was compiled by the National Toxicology Program, part of the Department of Health and Human Services.
The report, which summarizes studies conducted in Canada, China, India, Iran, Pakistan and Mexico, concludes that drinking water containing more than 1.5 milligrams of fluoride per liter is associated with lower IQ in children.
Some of the studies reviewed in the report suggest that children who had higher fluoride exposures scored 2 to 5 points lower on tests of intelligence known as IQ.
Federal health officials recommended in 2015 that drinking water have a level of 0.7 milligrams of fluoride per liter. The World Health Organization has said that the limit of 1.5 milligrams of fluorine per liter of water should not be exceeded.
According to the report, about 0.6% of the American population, or about 1.9 million people, consume water with natural fluoride content of 1.5 milligrams or more per liter of water.
“The findings from this report raise questions about how these people can be protected,” says researcher Ashley Malin with the University of Florida.
The 324-page report drew no conclusions about the risks of lower fluoride levels, saying more studies are needed. The report does not address the impact of excess fluoride on adults.
The American Dental Association, which supports water fluoridation, has criticized previous versions of the new analysis and Dr. Ashley Malin. The association said its experts were still reviewing the report.
Fluoride is a mineral that occurs naturally in water and soil. About 80 years ago, scientists found that people who consumed water with naturally high levels of fluoride also had healthier teeth, prompting efforts to use the mineral for better dental health.
