title: 135Cs activity and 135Cs/137Cs atom ratio in environmental samples before and after the Fukushima Daiichi Nuclear Power Plant accident.
abstract: (135)Cs/(137)Cs is a potential tracer for radiocesium source identification. However, due to the challenge to measure (135)Cs, there were no (135)Cs data available for Japanese environmental samples before the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. It was only 3 years after the accident that limited (135)Cs values could be measured in heavily contaminated environmental samples. In the present study, activities of (134)Cs, (135)Cs, and (137)Cs, along with their ratios in 67 soil and plant samples heavily and lightly contaminated by the FDNPP accident were measured by combining γ spectrometry with ICP-MS/MS. The arithmetic means of the (134)Cs/(137)Cs activity ratio (1.033 ± 0.006) and (135)Cs/(137)Cs atom ratio (0.334 ± 0.005) (decay corrected to March 11, 2011), from old leaves of plants collected immediately after the FDNPP accident, were confirmed to represent the FDNPP derived radiocesium signature. Subsequently, for the first time, trace (135)Cs amounts before the FDNPP accident were deduced according to the contribution of global and FDNPP accident-derived fallout. Apart from two soil samples with a tiny global fallout contribution, contributions of global fallout radiocesium in other soil samples were observed to be 0.338%-52.6%. The obtained (135)Cs/(137)Cs database will be useful for its application as a geochemical tracer in the future.
authors.affiliation: Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan.|Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences; Beijing Engineering Research Center of Radiographic Techniques and Equipment, Beijing 100049, China.
authors.forename: Guosheng
authors.initials: G
authors.lastname: Yang
authors.affiliation: Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Tazoe
authors.affiliation: Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Yamada
mesh_terms: D000465:Algorithms; D002588:Cesium Radioisotopes / Q000032:analysis*; D004777:Environment; D062406:Fukushima Nuclear Accident; D005843:Geography; D007564:Japan; D008962:Models, Theoretical; D055848:Nuclear Power Plants; D010944:Plants / Q000737:chemistry; D011834:Radiation Monitoring / Q000295:instrumentation / Q000379:methods; D011848:Radioactive Pollutants / Q000032:analysis*; D012987:Soil / Q000737:chemistry; D012990:Soil Pollutants, Radioactive / Q000032:analysis; D053719:Tandem Mass Spectrometry / Q000379:methods; D013997:Time Factors; D014875:Water Pollutants, Radioactive / Q000032:analysis
chemical_list: D002588:Cesium Radioisotopes; D011848:Radioactive Pollutants; D012987:Soil; D012990:Soil Pollutants, Radioactive; D014875:Water Pollutants, Radioactive