On the population dose close to the Semipalatinsk Nuclear Test Site

Full text: As a result of nuclear weapon tests at the Semipalatinsk Nuclear Test Site (SNTS) radiation exposure of inhabitants in surrounding villages has occurred over a period of several decades. Despite a number of published reports the determination of cumulative doses to the associated population and its uncertainty has not been finalized yet. Among the factors complicating this task are a) the time passed, b) the lack of direct personal dosimetry within the population possibly exposed, c) significant migration (out and in), d) inhomogeneous distribution of radionuclide deposition, e) new settlers at the SNTS and f) economic activities at the SNTS. This paper reports on the contribution of the ISTC-project K-465.2 'Complex examination of Semipalatinsk Test Site Region's population by advanced dosimetry methods' in assessing the population dose. The main results have been obtained during a period of three years by using the recent methodological progress made in EPR dosimetry on tooth enamel. Tooth enamel of people from settlements Dolon, Bodene, Cheremushki, Mostik, which were affected mainly by the first atomic explosion 1949, settlement Sarjal, affected by the first thermonuclear explosion in 1953, and as a control village Maysk, where radiological and meteorological records suggest that there was no significant radionuclide deposition near this village despite its position at the borders of SNTS, were investigated. Fresh tooth samples were used, which reflect well the current radiological situation. Additional measurements included e.g. environmental monitoring and in-vivo monitoring. EPR results suggest the existence of two sub-populations with different dose distributions: One with doses in the range of expected values from both natural background and SNTS testing, and another one with still higher doses not explained by the observed radioactive contamination. This finding is rather surprising. Additional research is needed to obtain a better statistic especially on the second subpopulation and a better insight into causes of high radiation doses observed within this group. (author)