@article{oai:u-ryukyu.repo.nii.ac.jp:02008088,
 author = {富濱, まどか and 山入端, 茜 and 古川, 雅英 and Tomihama, Madoka and Yamanoha, Akane and Furukawa, Masahide},
 issue = {100},
 journal = {琉球大学理学部紀要, BULLETIN OF THE FACULTY OF SCIENCE UNIVERSITY OF THE RYUKYUS},
 month = {Sep},
 note = {As a part of study to estimate the background radiation level in Japan, radon (^<222>Rn) concentrations of inland waters collected from Okinawa Island, main island of Okinawa prefecture, were measured with a simple liquid scintillation counter. The radon is an alpha emitting natural radioactive element with half-life of 3.8 days originated from the decay of ^<238>U. The arithmetic mean± standard deviation of the concentration of subsoil waters collected at 29 points was calculated to be 23.1±6.3 Bq L^-1 Relatively high concentrations of 36 Bq L^ -1 and 43 Bq L^-1 were found in Motobu area, northwestern part of the island. Also the concentrations of ground water samples collected at 4 points in Gyokusen-dou, a limestone cave in the southern part of the island, were estimated to be ND (< 2.3 Bq L^-1) - 4.6 Bq L^- 1., 紀要論文},
 pages = {1--4},
 title = {沖縄島の陸水中ラドン濃度},
 year = {2015}
}