EPIDEMIOLOGICAL STUDY OF HEALTH EFFECTS IN FUKUSHIMA NUCLEAR EMERGENCY WORKERS-STUDY DESIGN AND PROGRESS REPORT.

Between 14 March and 16 December 2011, the radiation dose limit for emergency work was tentatively raised from an effective dose of 100-250 mSv by the Japanese Government after the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. The objective of this study is to clarify the long-term health effects of radiation on the emergency workers involved during that period, based on a detailed evaluation of the radiation exposures and long-term monitoring. The potential subjects of the study are the approximately 20 000 workers who were engaged in emergency operations at FDNPP during the period described above. During the first phase of this project, the first 5 years from 2014, we plan to set up a research scheme and establish a cohort. To date, the establishment of the scheme for general health examinations is nearly complete. As of 31 January 2017, 5419 emergency workers (27.4% of the subjects) have agreed to participate in the study. We will continue our efforts to recruit additional potential subjects during the first phase to maximize the size of the cohort.