How can the Big Data Analyses help people affected by theFukushima Dai-ichi Accident?

The Fukushima Dai-ichi nuclear power plant accident dispersed a large amount of radioactive materials, which poses risks of internal and external exposure to the residents. Because the accident broke out in the internet era, a large amount of data were digitally collected. These include radiation-monitor data, tweets, GPS-enabled mobile-phone position data, car navigation data, and so on. Analyses of such “big data” are important to assess the risks of residents and to make plans for countermeasures. On the other hand, there have been many problems regarding the data publication method, and how to archive the collected data. Particular difficulties exist in the handling of personal radiation exposure data, due to the lack of common infrastructure, and more importantly, due to the difficulty in reconciling the data handling with the personal data protection act.

I will show several examples of collected and published data, and discuss what we have learned from such data; in particular, it has become clear that the internal exposure level of Fukushima residents is much lower than was initially estimated from the soil contamination level and from the knowledge gained from the Chernobyl accident.


Dr. Ryugo Hayano is professor of experimental nuclear physics at the University of Tokyo. His research concerns fundamental symmetries and interactions of nature using the spectroscopy of exotic atoms. He earned his Ph.D from the University of Tokyo in 1979, and he held professorship at the National Laboratory for High Energy Physics (KEK) before returning to Tokyo in 1986. In 2008 he received the Nishina Memorial Prize, the most prestigious physics prize in Japan, for the study of antiprotonic helium atoms. He is the spokesperson of ASACUSA collaboration at CERN’s antiproton decelerator facility. Since March 2011, his tweets related to the Fukushima Dai-ichi accident attracted some 150,000 followers; his activities in Fukushima include systematic measurement of school lunch for radiocesium, study of internal exposures using whole body counters, and analyses of GPS-enabled mobile phone data to visualize the flow of people around Fukushima Dai-ichi.