Deposition of 137Cs in Rokkasho, Japan and its relation to Asian dust.
Biweekly atmospheric depositions of (137)Cs were measured in Rokkasho, Aomori, Japan from March 2000 to March 2006 to study recent (137)Cs deposition. Although the deposition level was generally lower than the detectable limit, deposition samples collected in spring occasionally had measurable levels of (137)Cs. The annual (137)Cs deposition from 2001 to 2005 was 0.04-0.69 Bq m(-2) with a mean value of 0.27 Bq m(-2). Depositions of insoluble Al, Fe and Ti were strongly correlated with the (137)Cs deposition, suggesting that suspension of soil particles was the main source of the recent (137)Cs deposition. Asian dust events were coincident with some of the significant (137)Cs depositions in spring. It was found that the ratios of (137)Cs/Al and Fe/Al could be used as indices for discriminating Asian dust from suspension of the local surface soil. Backward trajectory analysis suggested southern Mongolian and northeastern China regions as sources of the significant (137)Cs depositions.
Akata
Naofumi
N
Department of Radioecology, Institute for Environmental Sciences, Rokkasho, Aomori 039-3212, Japan. nao@ies.or.jp
Hasegawa
Hidenao
H
Kawabata
Hitoshi
H
Chikuchi
Yuki
Y
Sato
Tadahiro
T
Ohtsuka
Yoshihito
Y
Kondo
Kunio
K
Hisamatsu
Shun'ichi
S
D000396:Air Pollutants, Radioactive / Q000032:analysis*; D000535:Aluminum / Q000032:analysis; D001272:Atmosphere / Q000032:analysis; D002588:Cesium Radioisotopes / Q000032:analysis*; D004391:Dust / Q000032:analysis*; D007501:Iron / Q000032:analysis; D007564:Japan; D011834:Radiation Monitoring; D011847:Radioactive Fallout; D014025:Titanium / Q000032:analysis
D000396:Air Pollutants, Radioactive; D002588:Cesium Radioisotopes; D004391:Dust; D011847:Radioactive Fallout; D000535:Aluminum; D014025:Titanium; D007501:Iron