Blood is thicker than water: Flaws in a National Toxicology Program study.

Municipal fluoridation was a mid-twentieth century innovation based on the medical hypothesis that consuming low doses of fluoride when young provided protection against cavities with only a small risk of mild dental fluorosis, a cosmetic effect. In the 21st century, more than half of American teens are afflicted by dental fluorosis with approximately one in five having moderate to severe dental fluorosis in at least two teeth. Scientific literature since the 1990s has found that even low doses of fluoride adversely affect cognitive-behavioral development and that deficits are correlated with the severity of dental fluorosis in afflicted individuals.