Endo Satoru, Tomita Junpei, Tanaka Kenichi, Yamamoto Masayoshi, Fukutani Satoshi, Imanaka Tetsuji, Sakaguchi Aya, Amano Hikaru, Kawamura Hidehisa, Kawamura Hisao, Apsalikov Kazbek N, Gusev Boris I, Whitehead Neil E, Shinkarev Sergey, Hoshi Masaharu
Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan.
Radiat Environ Biophys. 2008 Jul;47(3):359-65. doi: 10.1007/s00411-008-0162-3. Epub 2008 Mar 6.
Dolon village, located about 60 km from the border of the Semipalatinsk nuclear test site, is known to be heavily contaminated by the first USSR atomic bomb test in August 1949. Soil samples around Dolon were taken in October 2005 in an attempt to evaluate internal thyroid dose arising from incorporation of radioiodine isotopes (mainly (131)I). Iodine-129 in soil was measured by using the technique of accelerator mass spectrometry. The (129)I/(127)I atom ratios measured were in the range from 3.3 x 10(-9) to 3.3 x 10(-7). These values were within the range of the current background level ( approximately 10(-9) to 10(-7)) in the environment, including contributions from the global fallout of atmospheric nuclear tests and local fallout of nuclear facilities. The (129)I atom accumulated level in soil ranged from 1.28 x 10(13) to 1.59 x 10(14) atoms m(-2), the average (8.0 x 10(13)) of which was higher than the background level of (2-5) x 10(13). From the relationship between (129)I and( 137)Cs (corrected for background and decay from 1949 to 2005) accumulated levels, the background level of (129)I and the (129)I/(137)Cs ratio around Dolon were estimated to be (6.4 +/- 0.4) x 10(13) atoms m(-2) and 0.25 +/- 0.16, respectively. This (129)I/(137)Cs ratio is almost similar to the fission yield ratio for (239)Pu fast fission (0.24).
