Differences in Fallout-Derived ¹³⁷Cs and Naturally-Derived ¹³³Cs Transfer to Fruit in Persimmon Tree

Abstract

To confirm the contamination by radiocaesium, the concentrations of ¹³⁷Cs and ¹³³Cs of Japanese persimmon fruits and soils were measured in several orchards. Over 3 years, the ¹³⁷Cs concentration tended to decrease in many orchards, and there was no significant difference in the transfer factor. Additionally, 5 to 7 years after the accident, the effect of above-ground contamination seemed to be decreasing, and radiocaesium contamination by roots was likely negligible. The ¹³³Cs concentration in the soil was similar in all orchards; however, the ¹³³Cs concentration of fruits in one orchard was higher than that in the other orchards.