Characteristics of radon and thoron exhalation rates in Okinawa, subtropical region of Japan
Characteristics of radon and thoron exhalation rates in Okinawa, subtropical region of Japan
复制标题
日本亚热带冲绳县氡气和钍气呼出率特征
DOI：
10.1093/rpd/ncs220
复制
发表时间：
2012
影响因子：
1
通讯作者：
M. Furukawa
中科院分区：
文献类型：
--
作者：
Y. Shiroma;S. Kina;T. Fujitani;M. Hosoda;A. Sorimachi;T. Ishikawa;S. K. Sahoo;S. Tokonami;M. Furukawa
在日本亚热带地区冲绳县的三个岛屿上，利用硫化锌(银)闪烁探测器的累积技术，在总共88个点进行了地面氡析出率和氡析出率的现场测量。算术平均值为1~137MBq m−2s−1和32~6244(1801)MBq m−2s−1。在53个测点的表层土壤样品中，~(238)U和~(232)Th系列浓度估计分别为17.9-254.0(64.0)Bq kg−1干和17.8-136.1(58.8)Bq kg−1干。最大速率和最大浓度出现在暗红壤地区。最近的研究有力地表明，土壤的基质可能是来自中国东南部的风尘，那里是一个高本底辐射区。因此，风尘被认为是冲绳氡和索龙呼出的增强剂。
Radon and thoron exhalation rates from the ground surface were estimated in three islands of Okinawa Prefecture, a subtropical region of Japan.In situmeasurements of the exhalation rates were conducted at a total of 88 points using an accumulation technique with a ZnS(Ag) scintillation detector. The radon and thoron exhalation rates were calculated to be 1–137 (arithmetic mean: 21) mBq m−2s−1and 32–6244 (1801) mBq m−2s−1, respectively. In the surface soil samples collected at 53 measurement points,238U and232Th series concentrations were estimated to be 17.9–254.0 (64.0) Bq kg−1dry and 17.8–136.1 (58.8) Bq kg−1dry, respectively. The maximum rates and concentrations were observed in the dark red soil area. Recent studies strongly suggest that the base material of the soils may be the eolian dust derived from the southeastern part of China, a high background radiation area. The eolian dust is, therefore, considered to be an enhancer for the radon and thoron exhalations in Okinawa.