Report on the status of radioactive contamination from Iitate Village

Accident of Fukushima Daiichi NPP caused serious radioactive contamination in Iitate Village, Fukushima Prefecture. Ito, one of the villagers, started investigating the pollution status of soil and plants, and he also recorded the daily external exposure dose to investigate the radiation environment when living in Iitate Village. We report here a part of the actual state of pollution after 11 years. Contamination in soil varied widely from location to location. Although ¹³¹I found in the soil just after the accident disappeared rapidly, radioactive cesium remained longer. A survey in 2019 showed that even decontaminated areas averaged over 10,000Bq/kg, while uncleaned area, which is 84% of the Village, still averaged as high as over 40,000Bq/kg. The decontamination might be done incompletely, or the effect was lost over time as the uncleaned area expands widely. The pollution of plants in the village has been varied widely, not necessarily reflecting the soil doses. Since cesium was strongly adsorbed on the soil, the dose of plants decreased year by year, but high pollution of wild plants and mushrooms continues. From the daily exposure doses recorded by Ito, the indoor and outdoor exposure doses were estimated and compared with the results of aircraft monitoring by public institutions and the records at the ground dose monitoring post. When staying outdoors, the exposure dose was close to that of aircraft monitoring, which exceeded the value of the ground monitoring post, while indoors, the exposure dose was suppressed, due to the decontamination around the residence and the shielding effect of the house. Contamination of plants and high dose rates in Iitate village indicates that it is difficult to regain the original life. What kind of future does this village have? (author)