Biophysics Laboratory, Urals Research Center for Radiation Medicine, Chelyabinsk, Russia.
Chelyabinsk State University, Chelyabinsk, Russia.
PLoS One. 2023 Aug 10;18(8):e0288479. doi: 10.1371/journal.pone.0288479. eCollection 2023.
Many residents of the Russian Southern Urals were exposed to radioactive environmental pollution created by the operations of the Mayak Production Association in the mid- 20th century. There were two major releases: the discharge of about 1x1017 Bq of liquid waste into the Techa River between 1949 and 1959; and the atmospheric release of 7.4 * 1016 Bq as a result an explosion in the radioactive waste-storage facility in 1957. The releases into the Techa River resulted in the exposure of more than 30,000 people who lived in riverside villages between 1950 and 1961. The 1957 accident contaminated a larger area with the highest exposure levels in an area that is called the East Urals Radioactive Trace (EURT). Current epidemiologic studies of the exposed populations are based on dose estimates obtained using a Monte-Carlo dosimetry system (TRDS-2016MC) that provides multiple realizations of the annual doses for each cohort member. These dose realizations provide a central estimate of the individual dose and information on the uncertainty of these dose estimates. In addition, the correlation of individual annual doses over realizations provides important information on shared uncertainties that can be used to assess the impact of shared dose uncertainties on risk estimate uncertainty.This paper considers dose uncertainties in the TRDS-2016MC. Individual doses from external and internal radiation sources were reconstructed for 48,036 people based on environmental contamination patterns, residential histories, individual 90Sr body-burden measurements and dietary intakes. Dietary intake of 90Sr resulted in doses accumulated in active bone marrow (or simply, marrow) that were an order of magnitude greater than those in soft tissues. About 84% of the marrow dose and 50% of the stomach dose was associated with internal exposures. The lognormal distribution is well-fitted to the individual dose realizations, which, therefore, could be expressed and easily operated in terms of geometric mean (GM) and geometric standard deviation (GSD). Cohort average GM for marrow and stomach cumulative doses are 0.21 and 0.03 Gy, respectively. Cohort average dose uncertainties in terms of GSD are as follows: for marrow it is 2.93 (90%CI: 2.02-4.34); for stomach and the other non-calcified tissues it is 2.32 (90% CI: 1.78-2.9).
许多居住在俄罗斯南乌拉尔的居民受到了 20 世纪中叶玛雅克生产协会运营所造成的放射性环境污染的影响。有两次重大的泄漏事件：1949 年至 1959 年期间，约有 1x1017 贝克勒尔的液态废物排入捷恰河；1957 年，放射性废物储存设施发生爆炸，导致 7.4x1016 贝克勒尔的放射性物质释放到大气中。排入捷恰河的污染物使 1950 年至 1961 年期间居住在河边村庄的 3 万多人受到了辐射。1957 年的事故使一个更大的区域受到了污染，其最高辐射水平位于一个被称为“东乌拉尔放射性痕迹（EURT）”的地区。目前，对暴露人群的流行病学研究是基于使用蒙特卡罗剂量测定系统（TRDS-2016MC）获得的剂量估计值进行的，该系统为每个队列成员的年度剂量提供了多种实现。这些剂量实现提供了个体剂量的中心估计值，并提供了这些剂量估计值不确定性的信息。此外，个体年度剂量在实现中的相关性提供了关于共享不确定性的重要信息，可用于评估共享剂量不确定性对风险估计不确定性的影响。本文考虑了 TRDS-2016MC 中的剂量不确定性。根据环境污染物模式、居住史、个体 90Sr 体负荷测量值和饮食摄入量，为 48036 人重建了来自外部和内部辐射源的个体剂量。90Sr 的饮食摄入导致活性骨髓（或简称骨髓）中积累的剂量比软组织中的剂量大一个数量级。大约 84%的骨髓剂量和 50%的胃部剂量与内部暴露有关。对数正态分布很好地拟合了个体剂量实现，因此可以用几何平均值（GM）和几何标准差（GSD）来表示和方便地操作。骨髓和胃部累积剂量的队列平均 GM 分别为 0.21 和 0.03 Gy。以 GSD 表示的队列平均剂量不确定性如下：骨髓为 2.93（90%CI：2.02-4.34）；胃部和其他非钙化组织为 2.32（90%CI：1.78-2.9）。
