Department of Nuclear Engineering, University of Dhaka, Dhaka, Bangladesh.
Isotopes Environ Health Stud. 2024 May;60(2):213-225. doi: 10.1080/10256016.2024.2317391. Epub 2024 Feb 19.
Terrestrial gamma radiation is one of the major outdoor radiation exposures to the general public that varies substantially based on the type and geological properties of the soil. The objective of this study is to evaluate the naturally occurring radioactive materials (NORMs) distribution and assess the hazard parameters in the riverbank soil within various industrial zones in the densely populated Dhaka and Chattogram cities of Bangladesh. The mean activities of Ra (37 ± 3), Th (58 ± 4), and K (1129 ± 18) Bqkg in the assessed soil samples were found to be slightly higher than the world average values 32, 35, and 420 Bqkg, respectively. The mean radium equivalent activity (207.49 Bqkg) and the external and internal hazard indices were within the recommended limits of 370 Bqkg and <1, respectively. The mean absorbed dose rate (99.47 nGyhr), annual effective dose (0.12 mSva), ELCR (4.27 × 10), and gamma level index (1.58) exceeded the world average values 59 nGyhr, 0.07 mSva, 2.9 × 10, and 1 respectively. However, the studied areas are safe from a radiological viewpoint with no radiation health hazard to the people. The results of this study can be utilized to produce factual baseline data for future studies.
陆地伽马辐射是公众主要的室外辐射照射之一，其随土壤类型和地质特性而有很大差异。本研究的目的是评估孟加拉国人口稠密的达卡和吉大港市各工业区内河岸土壤中天然放射性物质（NORMs）的分布，并评估其危害参数。评估土壤样本中 Ra（37±3）、Th（58±4）和 K（1129±18）的平均活度分别略高于世界平均值 32、35 和 420 Bqkg。镭当量活度（207.49 Bqkg）和外照射和内照射指数分别在推荐限值 370 Bqkg 和 <1 内。平均吸收剂量率（99.47 nGyhr）、年有效剂量（0.12 mSva）、ELCR（4.27×10）和伽马水平指数（1.58）分别超过世界平均值 59 nGyhr、0.07 mSva、2.9×10 和 1。然而，从辐射角度来看，这些研究区域是安全的，不会对人们的健康造成辐射危害。本研究的结果可用于为未来的研究提供事实基准数据。
