‘...higher fluoride exposure...is associated with lower IQ and other cognitive effects in children’
Conclusion: NTP (US National Toxicology Program) concludes that fluoride is presumed to be a cognitive neurodevelopmental hazard to humans. This conclusion is based on a moderate level of evidence that shows a consistent and robust pattern of findings in human studies across several different populations demonstrating that higher fluoride exposure (e.g., >1.5 mg/L in drinking water) is associated with lower IQ and other cognitive effects in children. Limited and weaker evidence is considered to provide an inadequate level of evidence that fluoride is associated with cognitive effects in adults.
Fluoride Action Network: https://fluoridealert.org/researchers/the-national-toxicology-program/part-3/