CsMPs in the forest and river ecosystems; A Case study of vertical distribution in the soil and migration through rivers

Tatsuno, Takahiro*; Nihei, Naoto*; Yoshimura, Kazuya  ; Ote, Nobuhito*

This study aimed to better understand the distribution of radioactive-cesium rich microparticles (CsMPs) in the soil and their migration through rivers during rainfall event. For soil investigation, CsMPs might be distributed in the soil surface layer within 0-5cm depth as in the case of RCs. This result suggested that CsMPs might be easily mobile due to soil erosion. Some CsMPs were detected in deeper soil layers, which might be due to their migration as colloids or due to bioturbation. CsMPs were detected only in the samples collected during rainfall event. This result indicate that CsMPs might enter the river due to soil erosion. In all samples collected during rainfall event, the proportion of CsMPs in particulate radioactive-cesium was a few percent in both rivers. Therefore, CsMPs might not affect the solid-liquid distribution coefficient in the river water when evaluated over the entire rainfall period.