Questions Surrounding Fluoride’s Impact on Children’s IQ

USA: A recent federal report has reignited the long-standing debate over the fluoridation of public drinking water, suggesting potential links between high fluoride levels and lower IQs in children. The U.S. Department of Health and Human Services’ National Toxicity Program (NTP) published the report this week, offering “moderate confidence” in its findings based on studies from several countries, including Canada, China, and India.

The review examined total fluoride exposure from all sources, rather than focusing solely on fluoridated drinking water. Nonetheless, the conclusions drawn from this review are likely to fuel ongoing debates, particularly among groups opposed to public water fluoridation. These findings could lead to renewed calls for local governments to reconsider or even ban the practice of adding fluoride to drinking water.

Public Health Benefits of Fluoridation

Despite the concerns raised by the NTP report, public health officials and dental experts continue to endorse water fluoridation as a critical measure to combat tooth decay. The Centers for Disease Control and Prevention (CDC) has recognized public water fluoridation as one of the top 10 public health achievements of the 20th Century. Organizations like the American Dental Association (ADA) and the American Academy of Pediatrics have long supported the practice, citing research that shows fluoridated water reduces tooth decay by 25% in both children and adults.

Linda Edgar, president of the ADA, reaffirmed the safety and efficacy of fluoride in drinking water, stating, “Decades of research and practical experience indicate that fluoride is safe and beneficial to oral health.”

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Safe Fluoride Levels: Where Is the Line?

The NTP report raised particular concerns about water sources that contain fluoride levels exceeding 1.5 milligrams per liter, linking such levels to consistently lower IQ scores in children. However, the report did not specify the degree to which IQ might be affected or whether adults could also be impacted by elevated fluoride levels.

Current U.S. guidelines from the Public Health Service recommend that fluoride levels in public water systems be maintained at 0.7 milligrams per liter. In contrast, the World Health Organization sets the upper limit at 1.5 milligrams per liter. According to the report, water sources exceeding this threshold might pose risks to children’s cognitive development.

Howard Pollick, a fluoride expert with the ADA and a professor at the University of California, San Francisco, emphasized that most Americans have no cause for concern, as fluoride levels in their communities are well within safe limits. However, he expressed concern for the approximately 1.9 million Americans who, as of 2020, received water from systems with fluoride concentrations at or above 1.5 milligrams per liter.

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“The question now is whether [the EPA’s threshold] should perhaps be lowered to 1.5,” Pollick remarked, pointing out that the current Environmental Protection Agency (EPA) standard—2 milligrams per liter—aims to protect children from severe dental fluorosis, a condition that can weaken or discolor teeth.

Potential Impact on Public Water Policies

The NTP report is likely to embolden groups that have long opposed water fluoridation due to concerns about its potential effects on cognitive development. David Kennedy, a retired dentist and treasurer of the Preventative Dental Health Association, asserted, “It does not belong in our food, our water or our toothpaste,” in response to the report’s findings.

The Fluoride Action Network, which campaigns to end water fluoridation, highlighted a decrease in the number of Americans served by fluoridated water systems—from 74.6% in 2012 to 72.7% in 2020. The organization also noted that over 1,400 communities ceased adding fluoride to their water between 2010 and 2020.

Pollick expressed concern that the report might prompt city councils and other local authorities to face mounting pressure from constituents to end fluoridation. He cautioned that while the report adds to the discussion, it does not conclusively prove that fluoride causes lower IQ levels in children. Moreover, the confidence in the evidence remains “moderate,” according to the report’s authors.

As the debate continues, the future of water fluoridation in communities across the United States may hinge on the interpretation of these findings and the balance between perceived risks and the well-documented benefits of fluoride in public health.