Amer Hany A, Shawky S, Hussein Mohamed I, Abd el-Hady M L
National Center for Nuclear Safety and Radiation Control, Atomic Energy Authority, Nasr City 11762, Cairo, Egypt.
J Environ Monit. 2002 Aug;4(4):583-7. doi: 10.1039/b202693g.
Coal is largely composed of organic matter, but it is the inorganic matter in coal minerals and trace elements that have been cited as possible causes of health, environmental and technological problems associated with the use of coal. Some trace elements in coal are naturally radioactive. These radioactive elements include uranium (U), thorium (Th) and their numerous decay products, including radium (Ra) and radon (Rn). Although these elements are less chemically toxic than other coal constituents, such as arsenic, selenium or mercury, questions have been raised concerning the possible risk from radiation. In order to accurately address these questions and to predict the mobility of radioactive elements during the coal fuel cycle, it is important to determine the specific activity, distribution and form of radioactive elements in coal. The assessment of the radiation exposure from coal burning is critically dependent on the specific activity of radioactive elements in coal and in the fly ash that remains after combustion. The El-Maghara coal mine is the only producing coal mine in Egypt. It is located in the middle of the Sinai desert about 250 km north-east of Cairo, where a coal-fired power plant is intended to be built. In this study, a pre-operational radiological baseline of the site and the occupational radiation exposures due to radon progeny in the mine were determined. The specific activities of 226Ra, 232Th and 40K in soil and coal dust samples collected along the main gallery ranges were found to be 6-22.9, 9.6-47.3 and 77-489 Bq kg-1, respectively. Soil samples collected around the mine showed concentrations of 226Ra, 232Th and 40K in the ranges 2.7-20.2, 3.2-12.6 and 14.6-201 Bq kg-1, respectively. All of the mean values of radon progeny were lower than the action levels for working places recommended in the International Commission on Radiological Protection (ICRP) 65.
煤主要由有机物组成，但煤中的无机物和微量元素被认为是与煤炭使用相关的健康、环境和技术问题的可能成因。煤中的一些微量元素具有天然放射性。这些放射性元素包括铀（U）、钍（Th）及其众多衰变产物，包括镭（Ra）和氡（Rn）。尽管这些元素的化学毒性低于其他煤成分，如砷、硒或汞，但人们对辐射可能带来的风险提出了疑问。为了准确回答这些问题并预测煤炭燃料循环中放射性元素的迁移性，确定煤中放射性元素的比活度、分布和形态很重要。对燃煤辐射暴露的评估严重依赖于煤和燃烧后残留飞灰中放射性元素的比活度。埃尔-马加拉煤矿是埃及唯一的产煤矿。它位于开罗东北约250公里处的西奈沙漠中部，计划在那里建设一座燃煤发电厂。在本研究中，确定了该场地的运行前放射基线以及矿井中氡子体所致的职业辐射暴露。沿主巷道采集的土壤和煤尘样品中226Ra、232Th和40K的比活度分别为6 - 22.9、9.6 - 47.3和77 - 489 Bq kg-1。在矿井周围采集的土壤样品中226Ra、232Th和40K的浓度分别在2.7 - 20.2、3.2 - 12.6和14.6 - 201 Bq kg-1范围内。所有氡子体的平均值均低于国际放射防护委员会（ICRP）65号文件中推荐的工作场所行动水平。
