The activity concentration of soil samples of Bureti sub-county was measured using thallium-activated sodium iodide detector. To ascertain the level of radiation hazard to the public, gamma radiation dose rates were also estimated. The average activity concentration due to 40K, 226Ra and 232Th for soil samples are 1164 ± 70, 106 ± 8 and 79 ± 5 Bqkg−1, respectively. An average dose rate of 145 ± 10 nGyh−1 was recorded, which is about 2.5 times higher than the world average value of 60 nGyh−1(UNSCEAR). On the other hand, an average outdoor effective dose of 0.35 ± 0.02 mSvy−1 was measured, which is lower than the ICRP safety limit of 1 mSvy−1. This shows that the radiation hazards from naturally occurring terrestrial radionuclides in Bureti is low and therefore human radiation exposure is within the accepted limits.

中文翻译：

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肯尼亚 KERICHO 县 BURETI 分县土壤样品中天然存在的放射性核素

采用铊活化碘化钠检测仪测定布列提分县土壤样品的活性浓度。为了确定对公众的辐射危害程度，还估计了伽马辐射剂量率。40K、226Ra 和 232Th 对土壤样品的平均活度浓度分别为 1164 ± 70、106 ± 8 和 79 ± 5 Bqkg-1。记录的平均剂量率为 145 ± 10 nGyh-1，比世界平均值 60 nGyh-1（UNSCEAR）高出约 2.5 倍。另一方面，测得的平均室外有效剂量为 0.35 ± 0.02 mSvy-1，低于 ICRP 安全限值 1 mSvy-1。这表明 Bureti 天然存在的陆地放射性核素的辐射危害很低，因此人体辐射暴露在可接受的范围内。