Centre for Atomic Molecular Physics and Quantum Optics, University of Douala, PO Box 8580, Douala, Cameroon.
Research Centre for Nuclear Science and Technology, Institute of Geological and Mining Research, PO Box 4110, Yaoundé, Cameroon.
Environ Sci Pollut Res Int. 2022 Aug;29(36):54842-54854. doi: 10.1007/s11356-022-19781-z. Epub 2022 Mar 21.
The objective of the current study is to investigate the natural radioactivity of some building materials, the resulting long-term external and internal effective dose equivalents (EEDE and IEDE) analysis followed by indoor radon measurements, and the assessment of some radiological risk indicators associated with radon exposure. A total of 37 samples of building materials were analyzed with a sodium iodide detector (NaI (Tl)), and the computer code RESRAD-BUILD was used for the analysis of the EEDE and IEDE of the structural elements of the houses (walls and floor). For indoor radon measurements, 140 houses were selected, and in each of them was placed 01 RADTRAK dosimeter. Inhalation dose, total dose, and some radiological risk indicators were calculated. The specific activities of Ra, Th, and K for the overall sampled building materials were found to vary between 10 ± 2-52 ± 7, 10 ± 1-95 ± 10, and 31 ± 1-673 ± 20 Bq kg, respectively. The dwelling types with bare brick walls, cement mortar plastered walls, and concrete floors show EEDE and IEDE values well below the recommended limits. The corresponding dwelling type contributions to the measured average indoor radon concentration (42 ± 12 Bq m) are 22%, 13%, and 16%, respectively. Inhalation dose resulting from the measured indoor radon concentrations varies from 0.35 to 3.24 mSv y with a mean value of 0.96 ± 0.55 mSv y, which represents about 65% of the total dose simulated (1.49 ± 0.88 mSv y) by the RESRAD-BUILD code. The overall analysis of indoor radon-related radiological risk indicators shows low levels of risk relative to permissible limits.
本研究的目的是调查一些建筑材料的天然放射性，随后对长期的外部和内部有效剂量当量（EEDE 和 IEDE）进行分析，并对与氡暴露相关的一些放射风险指标进行室内氡测量。共分析了 37 种建筑材料样本，使用碘化钠探测器（NaI(Tl)），并使用 RESRAD-BUILD 计算机程序对房屋（墙壁和地板）的结构元素的 EEDE 和 IEDE 进行分析。为了进行室内氡测量，选择了 140 所房屋，在每所房屋中放置了 01 个 RADTRAK 剂量计。计算了吸入剂量、总剂量和一些放射风险指标。所采样的建筑材料的 Ra、Th 和 K 的比活度分别在 10±2-52±7、10±1-95±10 和 31±1-673±20 Bq kg 之间变化。裸露砖墙、水泥砂浆抹灰墙和混凝土地板的住宅类型的 EEDE 和 IEDE 值远低于建议限值。相应的住宅类型对测量的平均室内氡浓度（42±12 Bq m）的贡献分别为 22%、13%和 16%。由测量的室内氡浓度引起的吸入剂量变化范围为 0.35 至 3.24 mSv y，平均值为 0.96±0.55 mSv y，占 RESRAD-BUILD 代码模拟的总剂量（1.49±0.88 mSv y）的约 65%。与室内氡相关的放射风险指标的综合分析表明，相对于允许限值，风险水平较低。
