Moharram B M, Suliman M N, Zahran N F, Shennawy S E, El Sayed A R
Engineering Physics and Mathematics Department, Faculty of Engineering, Tanta University, Tanta, Egypt.
Appl Radiat Isot. 2012 Jan;70(1):241-8. doi: 10.1016/j.apradiso.2011.07.013. Epub 2011 Aug 3.
Using of building materials containing naturally occurring radionuclides as (238)U, (232)Th and (40)K and their progeny results in an external exposures of the housing of such buildings. In the present study, indoor dose rates for typical Egyptian rooms are calculated using the analytical method and activity concentrations of natural radionuclides in some building materials. Uniform chemical composition of the walls, floor and ceiling as well as uniform mass concentrations of the radionuclides in walls, floor and ceiling assumed. Different room models are assumed to discuss variation of indoor dose rates according to variation in room construction. Activity concentrations of (238)U, (232)Th and (40)K content in eight samples representative Clay soil and different building materials used in most recent Egyptian building were measured using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The specific activity for (238)U, (232)Th and (40)K, from the selected samples, were in the range 14.15-60.64, 2.75-84.66 and 7.35-554.4Bqkg(-1), respectively. The average indoor absorbed dose rates in air ranged from 0.005μGyh(-1) to 0.071μGyh(-1) and the corresponding population-weighted annual effective dose due to external gamma radiation varies from 0.025 to 0.345mSv. An outdoor dose rate for typical building samples in addition to some radiological hazards has been introduced for comparison.
使用含有天然存在的放射性核素如（238）U、（232）Th和（40）K及其子体的建筑材料会导致此类建筑物外壳受到外部照射。在本研究中，使用分析方法以及一些建筑材料中天然放射性核素的活度浓度来计算典型埃及房间的室内剂量率。假定墙壁、地板和天花板的化学成分均匀，以及墙壁、地板和天花板中放射性核素的质量浓度均匀。假定不同的房间模型来讨论根据房间结构变化的室内剂量率变化。使用电感耦合等离子体质谱法（ICP-MS）测量了代表埃及最近建筑中使用的粘土和不同建筑材料的八个样品中（238）U、（232）Th和（40）K的含量的活度浓度。所选样品中（238）U、（232）Th和（40）K的比活度分别在14.15 - 60.64、2.75 - 84.66和7.35 - 554.4Bqkg（-1）范围内。空气中的平均室内吸收剂量率范围为0.005μGyh（-1）至0.071μGyh（-1），并且由于外部伽马辐射导致的相应人口加权年有效剂量在0.025至0.345mSv之间变化。为了进行比较，还引入了典型建筑样品的室外剂量率以及一些放射性危害。
