Fluoride is one of the indispensable elements for the living being. Excess amounts of fluoride, however, may damage the teeth and bones. Fluoride may also injure the body’s soft tissues, resulting in nonskeletal fluorosis. To further investigate the influence of endemic fluorosis on childhood thyroid function and intelligence, we have selected school-aged children inflicted with dental fluorosis as the subject of our study. These children are from a region impacted with endemic fluorosis: Chaoyang City of Liaoning Province. The children in the study were tested for TSH (Thyroid Stimulating Hormone) and intelligence, and meaningful results were found. The results are reported in the following text.
… The results of the intelligence tests show that a high level of fluoride influences children’s IQ, which is consistent with some previous data. It is worth mentioning that the higher the degree of dental fluorosis, the more negative the impact on the children’s intelligence level. This is an issue which merits utmost attention. We believe that the low intelligence of children has no relation to the level of TSH. Although there are differences found in TSH values between the endemic area and nonendemic area groups, and between the lightly endemic and severely endemic groups, the individual values are all within the normal range…