Fluoride Action Network


SUMMARY: Wechsler Intelligence Test IQ scores of 160 children, 8–14 years old, from nine schools in an area of high fluoride and low iodine averaged 64.8 compared with 85.0 (p<0.01) for 169 children of the same ages from seven schools in an area with low iodine only. Among the first group 65 (40.6%) had IQs below 60, but only 23 (13.6%) among the second group had scores this low. In each group the IQs of the boys and girls did not differ significantly. Clearly, exposure to the combination of high fluoride and low iodine was more deleterious than to low iodine alone.


Among the 160 students in the high fluoride, low iodine group, 65 of them had an IQ lower than 69, low enough to be classified as having an intellectual deficit; these children made up 40.6% of the group. Among the 169 students from a solely iodine deficient environment, there were 23 with an intellectual deficit, 13.6% of the total. The two results are very significant (u =5.51, P<0.01).b In the high fluoride, low iodine zone, 68.1% of the children have IQs lower than 80, compared with 36.7% in the zone with low iodine alone (see Table).