Abstract
After the Fukushima Daiichi Nuclear Power Plant accident, there was a concern about the influence of radioactive cesium on local park users. This study focuses on the distribution of, and the factors affecting the radioactive cesium in the bottom sediment and hydrophytes of a park lake in the Fukushima prefecture. Surveys of the park lake conducted in 2013 and 2014 yielded the following findings. 1) There is no significant difference between the average 137Cs concentrations on the bottom sediment surface measured in 2013 and 2014.2) There is a negative correlation between the 137Cs and Si concentrations on the bottom sediment surface. However, there is a positive correlation between the 137Cs and K concentrations. 3) The 137Cs concentration tends to be highest at the surface of the bottom sediment, and the maximum 137Cs concentration depth is different at each investigation point. 4) The proportion of adhesion material in the 137Cs concentration of hydrophytes is 33-80%. 5) The transfer factor of 137Cs from the bottom sediment to the hydrophytes is 0.03-0.18, which is the same as that found in plants on land.
