134Cs and 137Cs activities in coastal seawater along Northern Sanriku and Tsugaru Strait, northeastern Japan, after Fukushima Dai-ichi Nuclear Power Plant accident.
A total of 37 seawater samples were collected at 10 sites along the coastline of the Northern Sanriku and Tsugaru Strait, 250-450 km north of the Fukushima Dai-ichi Nuclear Power Plant in April-December 2009 and May-June 2011, and analyzed for (134)Cs and (137)Cs activities using low-background γ-spectrometry. The (134)Cs and (137)Cs activities measured in these samples in May 2011 were found to be 2-3 mBq/L and 2.5-4 mBq/L, respectively. By June, these values had decreased by 25-45%/month and 5-30%/month, respectively. These results can be plausibly explained by surface infusion of these isotopes into the sea by atmospheric transport from Fukushima and their subsequent reduction by water migration to off-shore and deeper regions.
Low Level Radioactivity Laboratory, Institute of Nature and Environmental Technology, Kanazawa University, Nomi, Ishikawa 923-1224, Japan. mutsuo@llrl.ku-unet.ocn.ne.jp
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Inoue
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Kofuji
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Hamajima
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Nagao
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Yoshida
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Yamamoto
D002588:Cesium Radioisotopes / Q000032:analysis; D004190:Disasters; D055866:Earthquakes; D005843:Geography; D049674:History, 21st Century; D007564:Japan; D010140:Pacific Ocean; D011834:Radiation Monitoring / Q000706:statistics & numerical data*; D011847:Radioactive Fallout / Q000032:analysis*; D018788:Radioactive Hazard Release / Q000266:history* / Q000706:statistics & numerical data; D012623:Seawater / Q000737:chemistry; D013051:Spectrometry, Gamma; D013997:Time Factors; D057192:Tsunamis; D014875:Water Pollutants, Radioactive / Q000032:analysis*
D002588:Cesium Radioisotopes; D011847:Radioactive Fallout; D014875:Water Pollutants, Radioactive