Exposing children to high levels of fluoride is “consistently associated” with lower IQ, and potentially other neurodevelopmental issues, according to a report by the National Toxicology Program (NTP). “This review finds, with moderate confidence, that higher estimated fluoride exposures ..
. are consistently associated with lower IQ in children,” the report stated. NTP is a unit of the U.
S. Department of Health and Human Services. NTP defined high exposure as drinking water with fluoride concentrations that exceed the 1.
5 mg/L limit set by the World Health Organization. The allowable limits in the United States are different. While the U.
S. Food and Drug Administration (FDA) has set a threshold of 0.7 mg/L for fluoride presence in drinking water (including naturally occurring and added fluoride, or fluoridation), the U.
S. Environmental Protection Agency has a limit of 2 mg/L. As of April 2020, community water systems in the United States supplied water containing 1.
5 mg/L or more of naturally occurring fluoride to 0.59 percent of the country’s population, which comes to approximately 1.9 million people, NTP stated.
Around 1 million people were supplied water with 2 mg/L or more of naturally occurring fluoride. “There is also some evidence that fluoride exposure is associated with other neurodevelopmental and cognitive effects in children; although, because of the heterogeneity of the outcomes, there is low confidence in the literature for these other effects,” t.