Department of Basic Sciences, Tharaka University, P.O Box 193 (60215), Marimanti, Kenya.
Department of Physical Sciences, South Eastern Kenya University, P.O Box 170 (90200), Kitui, Kenya.
Radiat Prot Dosimetry. 2024 Jun 3;200(8):715-720. doi: 10.1093/rpd/ncae102.
This study used gamma ray spectrometry to determine the radiological safety of construction soil sampled randomly from Mbeere North region, Kenya. The mean activity concentration of 232Th, 238U, and 40K was 149.7 ± 2.8 Bqkg-1, 88.3 ± 2.4 Bqkg-1, and 490 ± 35 Bqkg-1, respectively. These averages exceed the world average for all the radionuclides. The radionuclides were non-uniformly distributed, with higher concentrations along the slopes and on the feet of the hills. The mean absorbed dose rate, indoor and outdoor annual effective dose, radium equivalent, external hazard index, and internal hazard index were 157.9 ± 4.4 nGh-1, 0.58 ± 0.02 mSvy-1, 0.39 ± 0.01 mSvy-1, 340.7 ± 9.2 Bqkg-1, 0.92 ± 0.02 and 1.14 ± 0.03, respectively. Among the radiation safety indicators, only the average internal hazard index exceeded slightly the acceptable safe limit. Therefore, soils of Mbeere North region are radiologically safe for use in brick making and construction of human habitats.
本研究采用伽马能谱法测定了肯尼亚姆贝雷北部地区随机采集的建筑土壤的放射安全性。232Th、238U 和 40K 的平均活度浓度分别为 149.7±2.8 Bqkg-1、88.3±2.4 Bqkg-1 和 490±35 Bqkg-1。这些平均值超过了所有放射性核素的世界平均值。放射性核素分布不均匀，在山坡和山脚下的浓度较高。平均吸收剂量率、室内和室外年有效剂量、镭当量、外照射指数和内照射指数分别为 157.9±4.4 nGyh-1、0.58±0.02 mSvy-1、0.39±0.01 mSvy-1、340.7±9.2 Bqkg-1、0.92±0.02 和 1.14±0.03。在辐射安全指标中，只有平均内照射指数略高于可接受的安全限值。因此，姆贝雷北部地区的土壤在用于制砖和建造人类住区方面具有放射安全性。
