ORIGINAL PAPER Iodine-129 measurements in soil samples from Dolon village near the Semipalatinsk nuclear test site Satoru Endo Æ Junpei Tomita Æ Kenichi Tanaka Æ Masayoshi Yamamoto Æ Satoshi Fukutani Æ Tetsuji Imanaka Æ Aya Sakaguchi Æ Hikaru Amano Æ Hidehisa Kawamura Æ Hisao Kawamura Æ Kazbek N. Apsalikov Æ Boris I. Gusev Æ Neil E. Whitehead Æ Sergey Shinkarev Æ Masaharu Hoshi Received: 29 June 2007 / Accepted: 17 February 2008 / Published online: 6 March 2008 Ó Springer-Verlag 2008 Abtract 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 9 10 -9 to 3.3 9 10 -7 . These values were within the range of the current background level (*10 -9 to 10 -7 ) in the envi- ronment, 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 9 10 13 to 1.59 9 10 14 atoms m -2 , the average (8.0 9 10 13 ) of which was higher than the background level of (2–5) 9 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) 9 10 13 atoms m -2 and 0.25 ± 0.16, respec- tively. This 129 I/ 137 Cs ratio is almost similar to the fission yield ratio for 239 Pu fast fission (0.24). Introduction In the Semipalatinsk nuclear test site area (SNTS) in Ka- zakhstan, more than 450 nuclear explosions including atmospheric, above-ground and underground tests were conducted from 1949 to 1989 by the former Soviet Union [1]. Consequently, several hundred thousand people living around the SNTS were affected by radioactive fallout from radioactive clouds by the nuclear tests [2–5]. Until now, considerable efforts have been made to investigate the radioactive contamination around the SNTS and radiation exposure to the residents living around the SNTS. Dolon village, located about 60 km from the border of the SNTS, is known to be one of the most heavily contaminated vil- lages around the SNTS. Radioactive clouds passed Dolon village three times on August 1949, July 1955, and August S. Endo (&)  K. Tanaka  N. E. Whitehead  S. Shinkarev  M. Hoshi Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan e-mail: endos@hiroshima-u.ac.jp J. Tomita  M. Yamamoto  A. Sakaguchi Low Level Radioactivity Laboratory, K-INET, Kanazawa University, Wake, Nomi, Ishikawa 923-1224, Japan S. Fukutani  T. Imanaka Research Reactor Institute, Kyoto University, Kumatori-cho, Osaka 590-0494, Japan H. Amano AMS Management Section, Mutsu Office, Japan Atomic Energy Agency, 4-24, Minato-machi, Mutsu, Aomori 035-0064, Japan H. Kawamura Kyushu Environmental Evaluation Association, 1-10-1, Matsukadai, Higashi-ku, Fukuoka 813-0004, Japan H. Kawamura Mutsu Institute for Oceanography, Japan Agency for Marine-Earth Science and Technology, 690, Kita-Sekine, Sekine, Mutsu, Aomori 035-0022, Japan K. N. Apsalikov  B. I. Gusev Kazakhstan Science Research Institute for Radiation Medicine and Ecology, 258, Gagarina Str, P.B. 49, Semipalatinsk 490026, Kazakhstan 123 Radiat Environ Biophys (2008) 47:359–365 DOI 10.1007/s00411-008-0162-3 Mass Analysis Department, Mutsu Marine Laboratory, Japan Marine Science Foundation, 4-24 Minato-machi, Mutsu-shi Aomori 035-0064, Japan