The Fukushima Dai-ichi NPP accident contaminated the soil of densely-populated regions in Fukushima Prefecture with radioactive cesium, which poses significant risks of internal and external exposure to the residents. If we apply the knowledge of post-Chernobyl accident studies, internal exposures in excess of a few mSv/y would be expected to be frequent in Fukushima. Our extensive whole-body-counter surveys however showed that the internal exposure levels of residents are much lower than estimated1); in 2012-2013, the 137Cs detection percentages (the detection limit being ~300 Bq/body) are about 1% for adults, and practically 0% for children. These results are consistent with those of many other measurements/studies conducted so far in Fukushima, e.g., rice inspection, foodstuff screening and duplicate-portion studies.
As such, the risk of external exposure is in general higher for the majority of residents in Fukushima. We have therefore started to deploy a new type of personal dosimeters, which can record integrated dose every hour with timestamps, in order to evaluate the risks of residents who wish to return to the 20-km evacuation zone.
In these efforts, the most crucial and time consuming is to re-establish communication at all levels; between residents and local medical staff, between experts and local staff, between the central government and municipalities, and so on.
1) Hayano RS, Tsubokura M, Miyazaki M, Satou H, Sato K, Masaki S, Sakuma Y., Proc Jpn Acad Ser B 2013; 89:157-163.
Montag, 16. Dezember 2013, 17:30 Uhr
(ab 17:00 Uhr Kaffee)
Universität Wien
Lise-Meitner-Hörsaal
Strudlhofgasse 4/1. Stock, 1090 Wien