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.
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http://dx.doi.org/10.1016/j.jenvrad.2007.01.007 | DOI Listing |
J Environ Radioact
January 2025
Department of Soil and Environment, Swedish University of Agricultural Sciences, Box 7070, 750 07, Uppsala, Sweden.
In this study, the long-term transfer of Cs from soil to grass on Swedish farms and fields, heavily contaminated after the 1986 radioactive fallout, was investigated. The study spans over 8-14 years, beginning in June 1986, and covers various soil types and agricultural practices. The transfer of Cs from soil to grass was highly variable, with transfer factors ranging from 1.
View Article and Find Full Text PDFMar Pollut Bull
January 2025
Ocean Environment Institute, Oceanic Consulting and Trading, Seoul, Republic of Korea.
This study simulated the dispersion of Cs in the North Pacific using a Lagrangian particle model, incorporating basin-wide atmospheric deposition and direct release from the Fukushima accident. Three experiments examined the impact of vertical diffusion and velocity on dispersion behavior. EXP01 and EXP02 assumed zero vertical velocity with different vertical diffusion coefficients (1 × 10 and 2 × 10 m/s, respectively), while EXP03 used a 3-day average vertical velocity and the same diffusion coefficient as EXP01.
View Article and Find Full Text PDFSci Total Environ
February 2025
School of Marine Sciences, Sun Yat-sen University, Zhuhai 519082, China. Electronic address:
This study comprehensively investigated the Cs signal in 294 sediment core samples from 132 lakes including reservoir and Gobi catchment in China. First, three Cs chrono-markers were observed: the 1963 peak corresponding to the maximum deposition of radioactive debris from global fallout, and two local sub-peaks corresponding to the time of the nuclear tests at Chinese Lop Nor site with a maximum in 1976, and to the Chernobyl accident in 1986. Second, the spatial distribution of sedimentation rates based on the 1963 Cs chrono-marker in Chinese lake sediment cores was studied.
View Article and Find Full Text PDFAppl Radiat Isot
March 2025
Department of Health and Safety Convergence Science, Korea University, Anam-ro 145, Seoul, 02841, Republic of Korea; Transdisciplinary Major in Learning Health System, Graduate School, Korea University, Seoul, 02841, Republic of Korea. Electronic address:
A 4π-field of view deep-learning-based collimator-less imaging system was designed with the Monte Carlo method and performance of the system was studied to verify the feasibility of system. A 4 × 4 × 4 voxelated single-volume GAGG(Ce) system and Co, Ba, Na, and Cs point sources at 2000 positions were modeled using Monte-Carlo N-particle transport code version 6 (MCNP6). Two types of the localized energy deposition acquired with a voxelated detector system with and without energy bins, were calculated.
View Article and Find Full Text PDFJ Environ Radioact
January 2025
Institute of Environmental Radioactivity, Fukushima University, 1 Kanayagawa, Fukushima City, Fukushima Prefecture, 960-1296, Japan; Faculty of Symbiotic Systems Science, Fukushima University, 1 Kanayagawa, Fukushima City, Fukushima Prefecture, 960-1296, Japan.
Cs tends to accumulate in ponds and dam reservoirs because of inputs from their catchments. Ponds contaminated by the Fukushima Daiichi Nuclear Power Plant accident have since been decontaminated. However, little attention has been paid to Cs accumulation after the decontamination measures, such as bottom sediment removal, especially for urban ponds with reportedly high Cs concentrations in their urban catchments.
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