A large amount of radiocesium emitted from the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident was deposited in terrestrial areas. It is therefore important to determine the quantity of radiocesium transported from these areas by hydrological processes to predict the future contamination status and propose effective countermeasures to reduce exposure. In this paper, we report the trend of the radiocesium concentration in 2 rivers nearby FDNPP and discuss the environmental factors on behavior of radiocesium.

We collected the tree sap in the Japanese cedar, and clarified the concentration of the dissolved radiocesium contained in the sap. It was shown that the amount of dissolved radiocesium in sap in each part was about 30 to 50% of the total amount of radiocesium at each part.