Gusain G S, Rautela B S, Sahoo S K, Ishikawa T, Prasad G, Omori Y, Sorimachi A, Tokonami S, Ramola R C
Department of Physics, Government Post Graduate College, New Tehri 249001, India.
Radiat Prot Dosimetry. 2012 Nov;152(1-3):42-5. doi: 10.1093/rpd/ncs148. Epub 2012 Aug 8.
Terrestrial gamma radiation is one of the important radiation exposures on the earth's surface that results from the three primordial radionuclides (226)Ra, (232)Th and (40)K. The elemental concentration of these elements in the earth's crust could result in the anomalous variation of the terrestrial gamma radiation in the environment. The geology of the local area plays an important role in distribution of these radioactive elements. Environmental terrestrial gamma radiation dose rates were measured around the eastern coastal area of Odisha with the objective of establishing baseline data on the background radiation level. The values of the terrestrial gamma radiation dose rate vary significantly at different locations in the study area. The values of the terrestrial gamma dose rate ranged from 77 to 1651 nGy h(-1), with an average of 230 nGy h(-1). During the measurement of the terrestrial gamma dose rate, sand and soil samples were also collected for the assessment of natural radionuclides. The activities of (226)Ra, (232)Th and (40)K from these samples were measured using a gamma-ray spectrometry with a NaI(Tl) detector. Activity concentrations of (226)Ra, (232)Th and (40)K ranged from 15.6 to 69 Bq kg(-1) with an average of 46.7 Bq kg(-1), from 28.9 to 973 Bq kg(-1) with an average of 250 Bq kg(-1) and from 139 to 952 Bq kg(-1) with an average of 429, respectively. The detailed significance of these studies has been discussed from the radiation protection point of view.
陆地伽马辐射是地球表面重要的辐射暴露源之一，它由三种原生放射性核素（226）镭、（232）钍和（40）钾产生。这些元素在地壳中的元素浓度可能导致环境中陆地伽马辐射的异常变化。当地的地质情况在这些放射性元素的分布中起着重要作用。为了建立背景辐射水平的基线数据，对奥里萨邦东部沿海地区周围的环境陆地伽马辐射剂量率进行了测量。研究区域内不同地点的陆地伽马辐射剂量率值差异显著。陆地伽马剂量率值范围为77至1651纳戈瑞每小时（nGy h(-1)），平均为230纳戈瑞每小时。在测量陆地伽马剂量率的过程中，还采集了沙子和土壤样本以评估天然放射性核素。使用配备碘化钠（铊）探测器的伽马射线能谱仪测量了这些样本中（226）镭、（232）钍和（40）钾的活度。（226）镭、（232）钍和（40）钾的活度浓度范围分别为15.6至69贝克勒尔每千克（Bq kg(-1)），平均为46.7贝克勒尔每千克；28.9至973贝克勒尔每千克，平均为250贝克勒尔每千克；139至952贝克勒尔每千克，平均为429贝克勒尔每千克。已从辐射防护的角度讨论了这些研究的详细意义。
