Lop Nor Influence investigation to population of Kazakhstan

Abstract

The method of electron spin resonance (ESR) dosimetry was applied to human tooth enamel to obtain individual absorbed doses of residents of Makanchi, Urdzhar and Taskesken settlements located near Kazakhstan-Chinese border (about 400 km to South-East from Semipalatinsk nuclear test site (SNTS) and about 1000 km from The Lop Nor Nuclear Weapons Test Base (China)). Since the ground and atmospheric nuclear tests (1964-1981) at Lop Nor, the people residing in these settlements have believed to be exposed heavily by radioactive fallout. Tooth samples were extracted according to medical reasons in a course of ordinary dental treatment. Kokpekty was chosen as control and was not subjected to any radioactive contamination and located 400 km to the Southeast from SNTS. It was found that the excess doses obtained after subtraction of the contribution of natural background radiation do not exceed 92 mGy for residents of Makanchi. For residents of Urdzhar, excess doses ranged up to 243 mGy for all ages. For residents of Taskesken, the maximum of excess dose were determined as 95 mGy.