Comparison of Cs-133 and Cs-137 Concentrations in Branches, Leaves, and Fruits in Each Lateral Branch of Individual Persimmon Trees

Due to the accident at the Fukushima Daiichi Nuclear Power Station of the Tokyo Electric Power Company, fruit trees such as persimmons were contaminated with radioactive materials. Eight years after the accident, relatively young lateral branches of persimmon trees, which had higher 137Cs concentrations in fruit than other trees, were sampled, and the 137Cs and 133Cs concentrations in the branches, leaves, and fruits were measured. A correlation was observed between the 137Cs concentrations in fruits and branches. 137Cs concentrations were different among the branches as well as in leaves and fruits. There was a correlation between 137Cs and 133Cs concentrations in the fruits, leaves, and branches. Therefore, it is possible that some of the 137Cs that fell on the bark may have migrated to the internal trees and accumulated in the same part as the 133Cs absorbed from the roots, and they were similarly translocated to the fruits via new branches.