No Evidence of Radiation Risk for Thyroid Gland among Schoolchildren around Semipalatinsk Nuclear Testing Site

To assess thyroid status among the schoolchildren around Semipalatinsk Nuclear Testing Site (SNTS), Kazakhstan, and to evaluate the current status of iodine deficiency in this area, we performed medical screening of schoolchildren in two villages, Kaynar and Karaul villages, East Kazakhstan Region, Republic of Kazakhstan, located within 100 km of SNTS. A total of 196 schoolchildren were chosen at random. Control groups comprised 250 schoolchildren from Nagasaki, an iodine-rich area, and 100 schoolchildren from Gomel, an iodine-deficient area contaminated by the Chernobyl Nuclear Power Plant accident. Ultrasound screening of thyroid revealed three cases of benign thyroid disease (two cases of goiter and one single cyst), but no cases suspicious of malignancy. The urinary iodine (UI) concentrations of subjects in Kaynar and Karaul ranged from 21.8 to 735.8 μg/L, 4.3% of whom showed low UI concentrations (