> About 40% of the nearly 600 women lived in cities with fluoridated drinking water [...]. Three to 4 years after the women gave birth, researchers gave their children an age-appropriate IQ test. After controlling for variables such as parental education level, birth weight, prenatal alcohol consumption, and household income, as well as exposure to environmental toxicants such as lead, mercury, and arsenic, they found that if a mother’s urinary fluoride levels increased by 1 milligram per liter, her son’s (but not her daughter’s) IQ score dropped by about 4.5 points. That effect is on par with the other recent studies looking at childhood IQ and low-level lead exposure.
So that's an average 1.3 IQ drop in cities with fluoride. For 1 gender. In an IQ test for 4 year olds. An IQ test.
Can anyone with more knowledge of statistics chime in? This feels like it cannot be statistically significant with n=600, a subgroup analysis and a test I cannot imagine being even remotely accurate (IQ test for 4 year olds)