Year-round variations in the fluvial transport load of particulate Cs in a forested catchment affected by the Fukushima Daiichi Nuclear Power Plant accident.

Particulate Cs was collected from stream water for 2 years to assess the long-term trend of Cs discharge from a forest after the Fukushima Nuclear Power Plant accident. A seasonal increase in the fluvial transport load of particulate Cs in suspended solids (SS) was observed in July-October when rainfall was abundant. The Cs load was controlled by the SS load. This control was attributed to cesium affinity for phyllosilicate clay minerals as verified by the low extractability of particulate Cs. These findings indicate the fluvial particulate Cs load is significantly related to the climate and geomorphological features of Japan. [ABSTRACT FROM AUTHOR]