Fluoride in drinking water linked to lower IQ in children

High levels of fluoride in drinking water are linked to lower IQs in children, according to a new US government report.

Since 1945, fluoride has been added to drinking water in the United States because it is believed to strengthen teeth and reduce the risk of tooth decay. Since 2015, federal health officials have recommended a fluoridation level of 0.7 milligrams per liter of water, down from the previous recommendation of 1.2 milligrams for five decades. The reduction was due in part to concerns about fluorosis, a condition that causes stains on teeth. The World Health Organization has set a “safe” limit of 1.5 milligrams of fluoride per liter of drinking water.

The report, initiated in 2016 and released Wednesday by the National Toxicology Program, part of the Department of Health and Human Services, is based on an analysis of previously published research from Canada, China, India, Iran, Pakistan and Mexico, which found that drinking water containing more than 1.5 milligrams of fluoride per liter – more than double the current US recommendation – was consistently associated with lower IQs in children, AP News reports.

– Since fluoride is such an important topic to the public and to public health officials, it was imperative that we made every effort to get the science right, Rick Woychik, director of the National Toxicology Program, said in a statement.

Millions affected

This is the first time a federal agency has made such a connection.

The report did not quantify exactly how many IQ points might be lost at different levels of fluoride exposure, but some of the studies reviewed in the report showed that IQs were two to five points lower in children who had higher exposures. The report also notes that about 0.6% of the US population, or about 1.9 million people, have water systems with naturally occurring fluoride levels of 1.5 milligrams or higher.

– The findings from this report raise the questions about how these people can be protected and what makes the most sense, Ashley Malin, a researcher at the University of Florida, who previously studied the effect of higher fluoride levels in pregnant women’s children, told the news agency.

The report does not answer the question of possible risks to adults.