A recent federal analysis was based on studies from other countries that have higher fluoride levels in their drinking water compared to the United States. Water fluoridation is often regarded as one of the major public health successes of the 20th century, known for significantly lowering tooth decay rates. There has been increasing debate among scientists regarding the potential connection between fluoride and reduced I.Q. scores in children. A thorough federal evaluation of past study results, published this week in JAMA Pediatrics, has intensified these worries. The study identified a notable negative correlation between exposure levels and cognitive abilities in children. Researchers from the National Institute of Environmental Health Sciences concluded that higher fluoride exposure was associated with lower IQ scores. All the studies analyzed were performed outside the United States, where the recommended fluoride levels in drinking water are quite low. At those levels, the evidence was insufficient to make conclusive statements. Observational studies cannot establish a cause-and-effect relationship. In countries with significantly higher fluoridation levels, the analysis revealed a dose-response relationship, where I.Q. scores declined consistently with rising fluoride exposure. Children are exposed to fluoride from various sources beyond just drinking water, including toothpaste, dental treatments, some mouthwashes, and certain foods like black tea, coffee, shrimp, and raisins. Certain medications and industrial releases also have fluoride present. We are currently unable to access the article content. Please enable JavaScript in your browser settings. We appreciate your patience as we confirm access. If you’re in Reader mode, please log out and sign in to your Times account, or subscribe to gain full access to The Times. We appreciate your patience as we confirm your access. Are you already a subscriber? Sign in.. Do you want access to all of The Times?