Hundie Tamiru Bayissa, Deressu Tilahun Tesfaye
Department of Physics, Nuclear Physics Stream, School of Computational and Natural Science, Addis Ababa University, P.O. Box: 1176, Addis Ababa, Ethiopia.
Radiat Prot Dosimetry. 2024 Dec 6;200(20):1951-1960. doi: 10.1093/rpd/ncae203.
Soil samples were collected from vegetable agricultural areas in and around Addis Ababa, and their levels of radioactivity were measured. Gamma spectrometry with high-purity germanium detector was used to quantify radioactivity level. The average concentration of 226Ra, 232Th, and 40K were 32.8 ± 2.1, 62.4 ± 4.4, and 544.3 ± 23.3 Bq kg-1 respectively. The mean values of 232Th and 40K are higher, whereas the value of 226Ra is comparable with world average values. Radiological hazard indices, including radium equivalent activity (Raeq), absorbed dose rate (Dr), outdoor annual effective dose equivalent (Deff), external hazard index (Hex), internal hazard index (Hin), and gamma radiation representative level index (Iγ), were calculated based on the activity concentration of 226Ra, 232Th and 40K. The mean values were 163.9 Bq kg-1, 78.7 nGy h-1, 0.10 mSv y-1, 0.44, 0.53, and 0.60 respectively. All indices are lower than global recommended limit values. These results revealed that radiation hazard due to radionuclides in the soil of the study area is insignificant.
从亚的斯亚贝巴及其周边的蔬菜种植区采集了土壤样本，并测量了它们的放射性水平。使用高纯度锗探测器的伽马能谱法来量化放射性水平。226镭、232钍和40钾的平均浓度分别为32.8±2.1、62.4±4.4和544.3±23.3贝克勒尔每千克。232钍和40钾的平均值较高，而226镭的值与世界平均值相当。基于226镭、232钍和40钾的活度浓度，计算了包括镭当量活度（Raeq）、吸收剂量率（Dr）、室外年有效剂量当量（Deff）、外照射危害指数（Hex）、内照射危害指数（Hin）和伽马辐射代表水平指数（Iγ）在内的放射危害指数。平均值分别为163.9贝克勒尔每千克、78.7纳戈瑞每小时、0.10毫希沃特每年、0.44、0.53和0.60。所有指数均低于全球推荐限值。这些结果表明，研究区域土壤中放射性核素造成的辐射危害微不足道。
