@article{oai:u-ryukyu.repo.nii.ac.jp:02011292, author = {城間, 吉貴 and 城間, 勝人 and 喜納, 正剛 and 細田, 正洋 and 安岡, 由美 and 赤田, 尚史 and 古川, 雅英 and Shiroma, Yoshitaka and Shiroma, Masato and Kina, Seigou and Hosoda, Masahiro and Yasuoka, Yumi and Akata, Naofumi and Furukawa, Masahide}, issue = {4}, journal = {保健物理}, month = {}, note = {In order to understand the source of atmospheric radon concentration in the Gyokusendo which is the limestone cave on Okinawa Island, the radon concentrations in the drip water from the ceiling were measured using a liquid scintillation counter. The arithmetic mean (± standard deviation) of radon concentration was 8.7 ± 2.0 kBq m^<-3>. This result suggests that the atmospheric radon in the cave was supplied from the drip water. When comparing the monthly precipitations which are considered to exert a profound influence on isotopic compositions of water seeping into a cave, the variation of radon concentration in the drip water was shown the delay of 60-90 days. The radon concentration in the soil water was estimated to be 47.3 kBq m^<-3>. Furthermore, the radon concentrations in the percolation water at the cave over a period of 9 to 10 days were calculated to be 9.3-7.7 kBq m^<-3>. The estimated radon concentration in the percolation water was almost equivalent with the measurement concentration in the drip water. These results suggest that the radon atoms in the drip water were generated from the soil above the cave. In other words, emanated radon from the soil particles might be the source of radon in the Gyokusendo., 論文}, pages = {218--226}, title = {沖縄県玉泉洞における洞内大気中ラドンの起源}, volume = {51}, year = {2016} }