RP 6-15

Epidemiological Study of Health Effects in Fukushima Emergency Workers (Abbreviation: NEW Study)


The emergency radiation exposure dose limit for the workers at the Fukushima Daiichi nuclear power plant of the Tokyo Electric Power Company (TEPCO) was raised from 100 mSv to 250 mSv during the period between March 14 and December 16, 2011. During this period, 174 out of approximately 20,000 emergency workers exceeded the dose limit of 100 mSv imposed for radiation workers in a consecutive five-year period during ordinary circumstances. The objective of this study is to clarify the long-term health effects of radiation on those 20,000 radiation emergency workers. Reliable epidemiological research on the cohort of radiation workers, the majority of whom were exposed to less than 100 mSv, is expected to lead to new findings about the risks of low-dose radiation exposure and its mechanisms. The conventional knowledge about health risks of radiation exposure derives from studies of A-bomb survivors, who were exposed to radiation one time only, while this study involves persistent exposure to mainly low-dose radiation. This study is expected to also bring about new findings on radiation dose and dose-rate effect, and the research results may contribute to establishment of more accurate radiation protection standards. We will also examine the psychological effects of engaging in such emergency work.