Fukushima Regional Collaborative Research Center, National Institute for Environmental Studies, 10-2 Fukasaku, Miharu, Fukushima, 963-7700, Japan.
National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan.
Sci Rep. 2023 Aug 29;13(1):14162. doi: 10.1038/s41598-023-41351-7.
The aggregated transfer factor (T) is commonly used to represent the actual transfer of radiocesium from soil to wild edible plants, but the values have shown substantial variation since the Fukushima nuclear accident. To elucidate the factors causing this variation, we investigated the effects of spatial scale and vertical Cs distribution in the soil on the variation of T-Cs values for one of the most severely contaminated wild edible plants, Eleutherococcus sciadophylloides Franch. et Sav. (Koshiabura). The variation in T-Cs values was not reduced by direct measurement of Cs deposition in soil samples from the Koshiabura habitat, as a substitute for using spatially averaged airborne survey data at the administrative district scale. The Cs activity concentration in Koshiabura buds showed a significant positive correlation with the Cs inventories only in the organic horizon of soil from the Koshiabura habitat. The ratio of Cs inventories in the organic horizon to the total Cs deposition in soil exhibited substantial variation, especially in broad-leaved deciduous forests that Koshiabura primarily inhabits. This variation may be the cause of the wide range of T-Cs values observed in Koshiabura buds when calculated from the total Cs deposition in soil.
聚集转移因子（T）通常用于表示放射性铯从土壤向野生食用植物的实际转移，但自福岛核事故以来，这些值显示出很大的变化。为了阐明导致这种变化的因素，我们研究了土壤中空间尺度和垂直 Cs 分布对最严重污染的野生食用植物之一，Sciadophylloides sciadophylloides Franch. et Sav.（Koshiabura）的 T-Cs 值变化的影响。通过直接测量 Koshiabura 栖息地土壤样本中的 Cs 沉积，无法减少 T-Cs 值的变化，因为这不能替代在行政区尺度上使用空间平均的空中调查数据。Koshiabura 芽中的 Cs 活度浓度与土壤中有机层的 Cs 库存呈显著正相关，仅在 Koshiabura 栖息地的土壤中。有机层中 Cs 库存与土壤中总 Cs 沉积的比例表现出很大的变化，尤其是在 Koshiabura 主要栖息的阔叶落叶林中。当从土壤中的总 Cs 沉积计算时，这可能是 Koshiabura 芽中观察到的 T-Cs 值范围很广的原因。
