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寳來 佐和子*; 村上 翔一*; 迫田 晃弘; 中下 留美子*; 國末 達也*; 石森 有
Environmental Monitoring and Assessment, 194(6), p.415_1 - 415_25, 2022/06
被引用回数：3 パーセンタイル：43.07(Environmental Sciences)本研究では、ウラン鉱山跡における微量元素の挙動および生物への環境影響を評価した。異なる三カ所において、堆積物・環境水・生物(昆虫,カエル,イモリ)に含まれる微量元素濃度を定量した。堆積物と環境水中のAsおよびU濃度は鉱滓ダムで最も高く、またこれら元素で最高値を示した生物(イモリ)も鉱滓ダムで採取したものであった。今回得られた生物の元素濃度・濃縮係数・
N値を踏まえると、本ウラン鉱山跡においてはイモリに危急種の可能性が考えられ、今後の更なる観察や評価が望まれる。
Cs and 
Cs radioactivity measurementsMalins, A.; 今村 直広*; 新里 忠史; 高橋 純子*; Kim, M.; 佐久間 一幸; 篠宮 佳樹*; 三浦 覚*; 町田 昌彦
Journal of Environmental Radioactivity, 226, p.106456_1 - 106456_12, 2021/01
被引用回数：6 パーセンタイル：35.21(Environmental Sciences)Understanding the relationship between the distribution of radioactive 
Cs and 
Cs in forests and ambient dose equivalent rates (
*(10)) in the air is important for researching forests in eastern Japan affected by the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident. This study used a large number of measurements from forest samples, including Cs and Cs radioactivity concentrations, densities and moisture contents, to perform Monte Carlo radiation transport simulations for *(10) between 2011 and 2017. Calculated *(10) at 0.1 and 1 m above the ground had mean residual errors of 19% and 16%, respectively, from measurements taken with handheld NaI(Tl) scintillator survey meters. Setting aside the contributions from natural background radiation, Cs and Cs in the organic layer and the top 5 cm of forest soil generally made the largest contributions to calculated *(10). The contributions from Cs and Cs in the forest canopy were calculated to be largest in the first two years following the accident. Uncertainties were evaluated in the simulation results due to the measurement uncertainties in the model inputs by assuming Gaussian measurement errors. The mean uncertainty (relative standard deviation) of the simulated *(10) at 1 m height was 11%. The main contributors to the total uncertainty in the simulation results were the accuracies to which the Cs and Cs radioactivities of the organic layer and top 5 cm of soil, and the vertical distribution of Cs and Cs within the 5 cm soil layers, were known. Radioactive cesium located in the top 5 cm of soil was the main contributor to *(10) at 1 m by 2016 or 2017 in the calculation results for all sites.
Malins, A.; 今村 直広*; 新里 忠史; Kim, M.; 佐久間 一幸; 篠宮 佳樹*; 三浦 覚*; 町田 昌彦
no journal, ,
PHITS Monte Carlo models were used to assess factors affecting ambient dose equivalent rates (H*(10)) in forests in Fukushima Prefecture. Three models were developed with different levels of detail to understand how the distribution of radioactive cesium within forests, shielding by trees and soil composition affect H*(10). The models were parametrized using measurements from deciduous and coniferous forests in Fukushima Prefecture.
Malins, A.; 今村 直広*; 新里 忠史; Kim, M.; 佐久間 一幸; 篠宮 佳樹*; 三浦 覚*; 町田 昌彦
no journal, ,
2011年から2017年までの福島県の森林内における周辺線量当量率(*(10))の計時変化を解析した。PHITSを用いて、森林内でのCsとCsの分布の経時変化が*(10)に与える影響を計算した。常緑針葉樹の樹冠から林床への放射性セシウムの移行は、事故後の早い時期には、CsとCsの放射崩壊率によって予想されるよりも1m高さの*(10)の減少を遅くするようであった。
