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| Title | Wildfires Oppositely Modify Radiocesium Speciation in Forest Litter and Soils: Evidence from Radiologically Contaminated Areas in Fukushima II. 137Cs concentrations in the solid samples before leaching and in the leachates obtained from unburned and burned litter of oak, red pine, and sugi collected from field sites. | |
|---|---|---|
| Author 1 | Yasunori Igarashi | |
| Author 2 | Seiji Hayashi | |
| Author 3 | Shoko Ito | |
| Author 4 | Masanori Tamaoki | |
| Authors 5- | Tadafumi Niizato, Yoshito Sasaki, Satomi Ito, Naoki Nomura, Hirotsugu Arai | |
| Subject | Land Surface | |
| Subject_sub1 | ||
| Subject_sub2 | ||
| Abstract | Wildfires in radiologically contaminated areas have raised concerns about radionuclide redistribution and increased radiation exposure. Most radionuclides, such as radiocesium (137Cs), remain in the charred residues and burned soil even after wildfires. This study investigated the impact of wildfires on 137Cs speciation in forest litter and soils following the Fukushima nuclear disaster. Extraction tests of 137Cs from unburned litter and soil artificially combusted at 250, 375, and 500 °C were conducted. 137Cs leaching from charred residues and burned soil collected from the field after the wildfires was tested. Sequential extraction was performed on soil obtained after the fire. The results indicated that water-soluble 137Cs from burned litter increased with combustion temperature. However, in artificially combusted soil, the release of water-soluble 137Cs was significantly reduced. In the field, 137Cs leaching from charred residues was lower than that from unburned litter. The fraction of water-soluble 137C in burned soil did not differ significantly from that in unburned soil. This suggests that the combustion temperature was relatively low and insufficient to promote significant leaching or soil drying. Furthermore, the combustion of soil organic matter may have altered the exchangeable form of 137Cs. Overall, these findings suggest that wildfires enhance 137Cs retention in soil, potentially delaying its release. This dataset indicates 137Cs concentrations in the solid samples before leaching and in the leachates obtained from unburned and burned litter of oak, red pine, and sugi collected from field sites. For samples 1–18, solid subsamples of approximately 3 g were used. The total 137Cs activity for each sample was calculated by multiplying the measured activity concentration in the solid sample by its sample amount, and by assuming that the measured activity concentration in the leachate corresponded to a total leachate volume of 30 mL. For samples 19–24 (Sugi litter), solid subsamples of approximately 4 g were taken and leached with 40 mL of solution, because the 3-g samples yielded activities below the detection limit. The leaching rate was then calculated as the ratio of 137Cs activity in the leachate to the total 137Cs activity (solid + liquid phases). | |
| Temporal coverage | 2017 | |
| Spatial coverage | 37.447317 N, 140.916456 E | |
| File format | Delimited | |
| Language | English | |
| Discovery metadata record | ||
| Publisher | Center for Research in Radiation, Isotopes, and Earth System Science, University of Tsukuba | |
| Publication year | 2025 | |
| Publication date | 10th of November | |
| Digital Object Identifier (DOI) | 10.34355/CRiES.U.Tsukuba.00308 Data Download (10KB) | |
| Short DOI | ||
| Citation text | Igarashi, Y., Hayashi, S., Ito, S., Tamaoki, M., Niizato, T., Sasaki, Y., Ito, S., Nomura, N., & Arai, H. (2025). Wildfires Oppositely Modify Radiocesium Speciation in Forest Litter and Soils: Evidence from Radiologically Contaminated Areas in Fukushima II. 137Cs concentrations in the solid samples before leaching and in the leachates obtained from unburned and burned litter of oak, red pine, and sugi collected from field sites. [Dataset]. Center for Research in Radiation, Isotopes, and Earth System Science, University of Tsukuba. https://doi.org/10.34355/CRiES.U.Tsukuba.00308 | |
| Serial at center | 00308 | |
| Serial at each Univ./Institute | TSUK0065 | |
| Key word 1 | radionuclide mobility | |
| Key word 2 | environmental impact | |
| Key word 3 | combustion temperature | |
| Key word 4 | radiocesium | |
| Key word 5 | speciation | |
| Remarks | ||