Fluoride Action Network


Soft tissue fluoride toxicity is well established. Several animal and human studies of the effect of fluoride on the thyroid gland have shown conflicting results. Endemic fluorosis and goitre are widespread in India with considerable overlapping in different geographical zones. We examined 22,276 individuals for  presence of goitre and dental fluorosis and estimated the fluoride and iodine content of their drinking water. Overall goitre and dental fluorosis prevalences were 14.0% and 12.2%, respectively, and were significantly and positively correlated. No significant relationship was observed between water iodine level and goitre. In the study area only 0.3% of cases were visible goitre (Grade-II and above) and all goitre cases were euthyroid. This suggests that fluoride-induced goitres are brought about by anatomical or structural changes rather than functional changes.