Dose reconstruction by tooth enamel EPR dosimetry for residents of settlements placed in vicinity of the radioactive fallout trace of the first test in SNTS

Abstract

The method of electron paramagnetic resonance (EPR) spectroscopy of tooth enamel has been used for individual radiation doses determination at residents of settlements Dolon, Mostik and Bodene in vicinity of the Semipalatinsk Nuclear Test Site in Kazakhstan. These settlements are placed near the central axe of radioactive fallout trace of the most contaminating surface nuclear explosion, which was conducted in 1949. Samples were extracted for medical reasons during ordinary dental treatment. According to information obtained by questioning, no teeth donors were subjected to x-ray procedures of jaw. Only molar teeth were used for dose determination, therefore effects of solar ultraviolet on dosimetric EPR signal in enamel can be excluded. It was found that the excess doses obtained after subtraction of the contribution of natural background radiation are 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 excepting one resident, for whom extremely high dose of 1.25 Gy is registered. For Bodene settlement, doses are higher than 100 mGy were obtained for two samples from the residents having enamel formed before 1949. In general, the obtained results are in agreement with the pattern of radioactive contamination of territory after the nuclear test of 1949.