Abstract
The method of electron spin resonance (ESR) dosimetry was applied to human tooth enamel to obtain individual absorbed doses of residents of settlements in the vicinity of the Semipalatinsk Nuclear Test Site (SNTS), Kazakhstan. Most of settlements (Dolon, Mostik, Bodene, Cheremushki, etc.) are located near the central axis of radioactive fallout trace from the most contaminating surface nuclear test, which was conducted in 29, August 1949. The distances between investigated settlements and Ground Zero are in the range 70 - 200 km from SNTS. The other settlements located in the radioactive fallout trace as a result of surface nuclear tests in 24, August 1956 (Znamenka), in 12, August 1953 (Sarzhal) and in 7, August 1962 (Kurchatov). Semipalatinsk city was included to investigation as a biggest city, which located close to SNTS.
Tooth samples were extracted according to medical indications in a course of ordinary dental treatment. (8 tooth samples were from control settlement Kokpekty, which were not subjected to any radioactive contamination and located 400 km to the Southeast from SNTS). Only molar teeth were used for dose determination, in which effects of solar ultraviolet on the radiation induced ESR signal in enamel are excluded.
It was found that the excess doses obtained after subtraction of the contribution of natural background radiation ranged up to about 450 mGy for residents of Dolon, whose tooth enamel was formed before 1949, and do not exceed 100 mGy for younger residents. For residents of Mostik, excess doses do not exceed 100 mGy for all ages. For Bodene settlement, excess doses higher than 100 mGy be obtained for two samples from the residents having enamel formed before 1949. For residents of Sarzhal village, the maximum of excess dose were determined as 138.2 mGy and for Residents of Znamenka maximum excess dose was about 268 mGy and for residents of Kurchatov city excess dose was about 63 mGy.
