title: Reassessment of (90)Sr, (137)Cs, and (134)Cs in the Coast off Japan Derived from the Fukushima Dai-ichi Nuclear Accident.
abstract: The years following the Fukushima Dai-ichi nuclear power plant (FDNPP) accident, the distribution of (90)Sr in seawater in the coast off Japan has received limited attention. However, (90)Sr is a major contaminant in waters accumulated within the nuclear facility and in the storage tanks. Seawater samples collected off the FDNPP in September 2013 showed radioactive levels significantly higher than pre-Fukushima levels within 6 km off the FDNPP. These samples, with up to 8.9 ± 0.4 Bq·m(-3) for (90)Sr, 124 ± 3 Bq·m(-3) for (137)Cs, and 54 ± 1 Bq·m(-3) for (134)Cs, appear to be influenced by ongoing releases from the FDNPP, with a characteristic (137)Cs/(90)Sr activity ratio of 3.5 ± 0.2. Beach surface water and groundwater collected in Sendai Bay had (137)Cs concentrations of up to 43 ± 1 Bq·m(-3), while (90)Sr was close to pre-Fukushima levels (1-2 Bq·m(-3)). These samples appear to be influenced by freshwater inputs carrying a (137)Cs/(90)Sr activity ratio closer to that of the FDNPP fallout deposited on land in the spring of 2011. Ongoing inputs of (90)Sr from FDNPP releases would be on the order of 2.3-8.5 GBq·d(-1) in September 2013, likely exceeding river inputs by 2-3 orders of magnitude. These results strongly suggest that a continuous surveillance of artificial radionuclides in the Pacific Ocean is still required.
authors.affiliation: Institut de Ciència i Tecnologia Ambientals & Departament de Física, Universitat Autònoma de Barcelona , 08193 Cerdanyola del Vallès, Spain.
authors.forename: Maxi
authors.initials: M
authors.lastname: Castrillejo
authors.affiliation: Laboratory of Ion Beam Physics, ETH-Zurich , Otto-Stern-Weg 5, 8093 Zurich, Switzerland.
authors.forename: Núria
authors.initials: N
authors.lastname: Casacuberta
authors.affiliation: Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution , Woods Hole, Massachusetts, 02543 United States.
authors.forename: Crystaline F
authors.initials: CF
authors.lastname: Breier
authors.affiliation: Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution , Woods Hole, Massachusetts, 02543 United States.
authors.forename: Steven M
authors.initials: SM
authors.lastname: Pike
authors.affiliation: Institut de Ciència i Tecnologia Ambientals & Departament de Física, Universitat Autònoma de Barcelona , 08193 Cerdanyola del Vallès, Spain.|Oceans Institute & School of Physics, The University of Western Australia , Crawley, WA, 6009 Australia.|School of Natural Sciences & Centre for Marine Ecosystems Research, Edith Cowan University , Joondalup, WA, 6027 Australia.
authors.forename: Pere
authors.initials: P
authors.lastname: Masqué
authors.affiliation: Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution , Woods Hole, Massachusetts, 02543 United States.
authors.forename: Ken O
authors.initials: KO
authors.lastname: Buesseler
mesh_terms: D002588:Cesium Radioisotopes / Q000032:analysis*; D004784:Environmental Monitoring; D062406:Fukushima Nuclear Accident; D010140:Pacific Ocean; D012623:Seawater / Q000737:chemistry*; D014875:Water Pollutants, Radioactive / Q000032:analysis*
chemical_list: D002588:Cesium Radioisotopes; D014875:Water Pollutants, Radioactive