The results of a new federal analysis were drawn from studies conducted in other countries, where drinking water contains more fluoride than in the United States.
Water fluoridation is widely seen as one of the great public health achievements of the 20th century, credited with substantially reducing tooth decay. But there has been growing controversy among scientists about whether fluoride may be linked to lower I.Q. scores in children.
A comprehensive federal analysis of scores of previous studies, published this week in JAMA Pediatrics, has added to those concerns. It found a significant inverse relationship between exposure levels and cognitive function in children.
