2018 Volume 67 Issue 1 Pages 11-20
Much effort has been made by Japanese experts to assess the dose to residents of Fukushima Prefecture in the aftermath of the 2011 nuclear disaster. Residents living near the Fukushima Daiichi Nuclear Power Plant (FDNPP) were ordered to evacuate promptly after the accident to minimize radiation exposure. Many papers performing individual dose measurement and estimation of these residents have already been published. This paper provides a brief overview of these publications by dividing the evaluation into the early-phase (< 1 year) and the late-phase (≥ 1 year) studies, and compiling the lessons learnt from the 2011 nuclear disaster. One common view of the studies by the Japanese experts is that the levels of exposure are generally low. Aside from the internal thyroid dose from short-lived radionuclides (mainly 131I) at the early phase, both the external and internal doses attributable to the nuclear disaster are comparable or less than those from natural radiations. A number of individual dose measurements at the late phase have provided useful information for understanding exposure situations in everyday life for people living in the affected area. One key remaining issue for the dose assessment is to evaluate the related uncertainty, in particular for the internal thyroid dose received at the early phase. Thus, there is a role for further studies to improve the certainty of dose estimations.