Department of Siting and Environment, Egyptian Nuclear and Radiological Regulatory Authority (ENRRA), Nasr City, Cairo 11762, Egypt.
Radiat Prot Dosimetry. 2020 Sep 16;190(3):331-341. doi: 10.1093/rpd/ncaa107.
The aim of this work was to use RESRAD-Build model to predict the resulting external and internal radiological doses received by the workers of manganese mine located in Southern Sinai. In order to achieve that goal, measurement of the activity concentrations of natural radionuclides in rock samples collected from the inside gallery of such mine, using hyper pure germanium (HPGe) detector. Radon gas concentrations were also measured. The average activity concentrations of 238U, 226Ra, 232Th, 40K and 210Pb in rock samples were 207.3, 155.5, 59.7, 304.5 and 119.3 Bq kg-1, respectively. The average radon activity concentration was 1254.6 Bqm-3, which is equivalent to 0.135 WL. The radon concentration increases further as going deep inside the mine up to 6238 Bqm-3. RESRAD-Build model occupational effective dose equivalent (EDE) received by the workers, from natural radionuclides, dominated by 222Rn emanated from the parent nuclide 226Ra.There was good agreement between the occupational annual EDE calculated from the measured rock samples and that predicted by modeling, with estimated values of 83.8 and 82.1 mSvy-1, respectively. This radiological dose assessment indicated the predominance of internal pathways owing to radon decay products, in both cases (measured and modeled). The occupational radiological dose from the inhalation of radon and radon decay products resulted in a high lung cancer risk based on the current measurements and ventilation conditions within the mine.
这项工作的目的是使用 RESRAD-Build 模型来预测位于南西奈锰矿工人所接受的外部和内部放射性剂量。为了实现这一目标，使用高纯锗（HPGe）探测器测量了从该矿内部画廊采集的岩石样本中天然放射性核素的活度浓度。还测量了氡气浓度。岩石样本中 238U、226Ra、232Th、40K 和 210Pb 的平均活度浓度分别为 207.3、155.5、59.7、304.5 和 119.3 Bq kg-1。平均氡活度浓度为 1254.6 Bqm-3，相当于 0.135 WL。随着深入矿山，氡浓度进一步增加，最高可达 6238 Bqm-3。RESRAD-Build 模型预测，矿工从天然放射性核素中接收到的职业有效剂量当量（EDE）主要来自母体核素 226Ra 释放的 222Rn。从测量的岩石样本计算得出的职业年 EDE 与模型预测值之间存在良好的一致性，分别为 83.8 和 82.1 mSvy-1。这种放射性剂量评估表明，由于氡子体衰变产物，内部途径占主导地位，这两种情况（测量和建模）均如此。基于当前的测量值和矿山内的通风条件，吸入氡及其子体导致的职业放射性剂量会导致肺癌风险增加。
