Radioactive contamination around the former Soviet Union's Semipalatinsk nuclear test site and estimation of internal radiation dose for people

前苏联在哈萨克斯坦塞米巴拉金斯克核试验场(SNTS)进行的核武器试验造成了试验场周围的大量放射性污染。Dolon村被认为是SNTS周围受放射性尘埃污染最严重的村庄之一。由模型计算的空气中的外部伽马射线剂量范围为1~2GY，而从教堂采集的砖样n Dolon的热释光测量接近0.5Gy.因此，在Dolon村，调查人员指出了该村在剂量估计方面的一些差异。为了重建多伦村的辐射剂量，根据多伦村及其附近村庄的土壤污染数据，调查了放射性羽流的宽度和中心轴位置。在本研究期间，还获得了多隆周围的土壤污染数据。结果表明，Cs-137和Pu-239,240的分布图呈峰状分布。烟羽的中心部分以一西格玛值1.5公里经过多伦市的居民区。与上述工作平行的是，为了评估居住在SNTS附近的普通人群目前的Pu和Cs-137水平，并估计相关的α剂量，我们测量了70多名居民尸骨样本中的Pu-239,240和U同位素。假设骨样中Pu-239,240的平均浓度为1955年瞬时吸入后45年的值，估算出45年的初始总剂量和有效剂量分别为10Bq和1.2mSv。成人的年总铀摄入量和60年的有效剂量估计分别为30Bq和0.1mSv。

Nuclear weapon tests by the former USSR at the Semipalatinsk Nuclear Test Site (SNTS) in Kazakhstan caused a vast amount of radioactive contamination around the test site. Dolon village is known as one of the most contaminated villages by radioactive fallout around SNTS. Calculated external gamma-ray dose in air by model ranged from 1 to 2 Gy, while TL measurement of a brick sample n Dolon taken from a church was close to about 0.5 Gy. Thus, In Dolon village, some discrepancies in the dose estimation for the village among investigators were pointed out. In relation to the effort to reconstract the radiation dose in Dolon village, the width and center-axis location of the radioactive plume were investigated based on the soil contamination data around Dolon and the nearby villages. Additional soil contamination data around Dolon were obtained during the period of this study. As a result, the plotted distribution formed a peak-like shape for Cs-137 and Pu-239,240. The center part of the plume passed over the residential area of Dolon with one sigma value of 1.5 km. Finally, 0.50 Gy of absorbed dose in air was derived as our tentative estimate for 1-year cumulative external dose in Dolon due to local fallout from the first USSR test in 1949.Parallel to the above works, to evaluate the present Pu and Cs-137 levels in the general population living near the SNTS and to estimate the associated alpha doses, Pu-239,240 and U isotopes in bone samples from more than 70 autopsies of residents were measured. By assuming that average concentration of Pu-239,240 in bone samples is the value at 45 years after instantaneous inhalation in 1955,the initial total and the effective dose for 45 years were estimated as 10 Bq and 1.2 mSv, respectively. The annual intake of total U and its effective dose for 60 years were estimated as 30 Bq for adult and 0.1 mSv, respectively, for chronic ingestion.