An observational study of 601 mother-child pairs from six cities in Canada hints at an apparent association between maternal exposure to fluoride during pregnancy and lower IQ scores measured in children ages 3 to 4. Community water has been fluoridated for decades to prevent tooth decay; a majority of US residents are supplied with fluoridated water, as are more than one-third of Canadian residents and about 3% of European residents.
Source: Study examines maternal exposure to fluoride in pregnancy, kids’ IQ scores