Results of tooth enamel EPR dosimetry for population living in the vicinity of the Semipalatinsk nuclear test site

Abstract

The method of electron paramagnetic resonance (EPR) dosimetry was used on human tooth enamel to obtain individual absorbed doses of residents of settlements in the vicinity of the Nuclear Test Site (SNTS) in Semipalatinsk region, Kazakhstan. Measured teeth were extracted according to medical indications. In total, 105 tooth enamel samples were analyzed, including eight tooth samples from control settlement Kokpekty, which is located 400 km to the Southeast from SNTS and was not subjected to any radioactive contamination. It was found that the excess doses obtained after subtraction of the contribution of natural background radiation ranged up to about 440 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 except in one resident, for whom an extremely high dose of 1250 mGy was registered. For Bodene settlement, excess doses higher than 100 mGy were obtained for two samples from the residents having enamel formed before 1949. An extremely high dose ( 2800 ± 400 mGy) was obtained for one resident of Semipalatinsk City. The average excess dose for Semipalatinsk samples with enamel formation before 1949 was determined close to the average excess dose for tooth enamel samples from Dolon village.