Forecast of future of radiocesium pollution on the cherry tree bark in Northern Fukushima Prefecture after the accident at TEPCO's Fukushima-Daiichi Nuclear Power Plant using data of current South Tohoku District of Japan and around Chernobyle

The current concentrations of radiocesium (¹³⁷Cs) on upper surface of cherry tree branch barks of the South Tohoku District of Japan are high. In 2017, these concentrations decreased to about half of that in 2014 When the accident at the Chernobyl Nuclear Power Plant occurred, the ¹³⁷Cs concentrations on cherry tree bark surfaces in the area were on same level as that in the Northern Fukushima Prefecture. This was about 1/100 of the concentration in Fukushima City in 2016. Autoradiography of the cherry tree bark samples obtained from the area revealed weak radioactive spots on the surface of the barks. ¹³⁷Cs pollution in cherry tree barks in the South Tohoku District is expected to decrease to about 1/100 of the initial concentration after thirty years. (author)