Health Physics Division, Atomic Energy Centre, Dhaka, Bangladesh.
Department of Nuclear Engineering, University of Dhaka, Dhaka, Bangladesh.
PLoS One. 2023 Oct 19;18(10):e0289113. doi: 10.1371/journal.pone.0289113. eCollection 2023.
This work presents the first in-depth study of soil radioactivity in the mangrove forest of Bangladesh part of the Sundarbans. It used HPGe gamma-ray spectrometry to measure the amount of natural radioactivity in soil samples from Karamjal and Harbaria sites of the world's largest mangrove forest. The activity concentrations of most of the 226Ra (14±2 Bqkg-1 to 35±4 Bqkg-1) and 232Th (30±5 Bqkg-1 to 50±9 Bqkg-1) lie within the world average values, but the 40K concentration (370± 44 Bqkg-1 to 660±72 Bqkg-1) was found to have exceeded the world average value. The evaluation of radiological hazard parameters revealed that the outdoor absorbed dose rate (maximum 73.25 nGyh-1) and outdoor annual effective dose (maximum 0.09 mSvy-1) for most samples exceeded the corresponding world average values. The elevated concentration of 40K is mainly due to the salinity intrusion, usage of fertilizers and agricultural runoff, and migration of waste effluents along the riverbanks. Being the pioneering comprehensive research on the Bangladesh side of the Sundarbans, this study forms a baseline radioactivity for the Sundarbans before the commissioning of the Rooppur Nuclear Power Plant in Bangladesh.
本研究首次深入研究了孟加拉国孙德尔本斯红树林地区的土壤放射性。研究采用 HPGe 伽马能谱法测量了世界上最大的红树林地区卡拉姆贾尔和哈里巴里地区土壤样本中的天然放射性活度。大多数 226Ra（14±2 Bqkg-1 至 35±4 Bqkg-1）和 232Th（30±5 Bqkg-1 至 50±9 Bqkg-1）的活度浓度均处于世界平均值范围内，但 40K 浓度（370±44 Bqkg-1 至 660±72 Bqkg-1）却超过了世界平均值。放射性危害参数的评估表明，大多数样本的室外吸收剂量率（最高 73.25 nGyh-1）和室外年有效剂量（最高 0.09 mSvy-1）均超过了相应的世界平均值。40K 浓度的升高主要是由于盐分入侵、肥料和农业径流的使用以及河岸沿线废污水的迁移所致。作为对孙德尔本斯孟加拉国一侧的开创性综合研究，本研究为孟加拉国罗普尔核电站投入运行前的孙德尔本斯形成了一个基线放射性水平。
