著者

友寄 喜貴 棚原 朗 武村 盛久 渡口 輝 平良 初男

出版者

日本地球化学会

雑誌

地球化学 (ISSN:03864073)

巻号頁・発行日

vol.31, no.4, pp.227-233, 1997

被引用文献数

3

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The activities of natural radionuclides, ²³⁸U, ²³⁴U, ²²⁶Ra, ²²⁸Ra, ²²²Rn, ²¹⁰Pb and ²¹⁰Po in ground waters collected from Okinawa Island were measured. The ²³⁴U/²³⁸U activity ratios in most samples showed more or less unity, whereas, relatively high values of 2.0-4.0 were obtained in samples from Motobu area. ²²²Rn activities in the ground waters were much higher than the other uranium series nuclides. The ²²²Rn/²²⁶Ra activity ratios ranged from 3000 to 29000, and those for ²¹⁰Po/²¹⁰Pb were from 0.08 to 0.82. On the whole, activities of the nuclides in the ground waters at the studied points showed higher in the order of ²²²Rn≫²¹⁰Pb>²³⁴U>²³⁸U>²²⁶Ra>²¹⁰Po. In addition to α_recoil dissolution, the selective absorption and/or desorption by some organic or inorganic substances in the aquifer may be happening.