Changes in International Organizations' Assessments
After the accident at Tokyo Electric Power Company (TEPCO)'s Fukushima Daiichi NPS, the World Health Organization (WHO) and the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) published reports on assessment of exposure doses due to the accident and on health effects of radiation exposure.
The WHO published a report on provisional exposure dose assessment in May 2012, and a report on provisional health risk assessment in February 2013. The assessment by the WHO aimed to estimate people's exposure doses for the first one year after the accident and identify areas requiring emergency measures. Accordingly, based on limited information and by setting conservative assumptions in order to avoid underestimation, the WHO assessed the maximum exposure doses that could be possible.
The UNSCEAR 2013 Report aimed to achieve the most realistic assessment of exposure levels and radiation risks due to the accident to the extent possible. However, the Report also states that all the results of such assessment contain certain uncertainties due to the incompleteness of knowledge or information and depending on setting of assumptions.
Therefore, the UNSCEAR conducted ongoing follow-ups to systematically collect and assess new information published after the publication of the UNSCEAR 2013 Report. The results of the follow-ups were compiled into three White Papers from 2015 to 2017, and the UNSCEAR 2020/2021 Report, which reflects new knowledge obtained after the publication of the UNSCEAR 2013 Report, was published in March 2021.
In the UNSCEAR 2020/2021 Report, doses are estimated using new knowledge on exposure dose assessment in order to reduce the uncertainties in the dose estimation in the UNSCEAR 2013 Report.
- WHO Reports on preliminary dose estimation and health risk assessment:
- Preliminary dose estimation from the nuclear accident after the 2011 Great East Japan Earthquake and Tsunami (2012)
- Health risk assessment from the nuclear accident after the 2011 Great East Japan earthquake and tsunami, based on a preliminary dose estimation (2013)
- 2013 Annual Report by the UNSCEAR:
- SOURCES, EFFECTS AND RISKS OF IONIZING RADIATION UNSCEAR 2013, Report, Volume I, REPORT TO THE GENERAL ASSEMBLY SCIENTIFIC ANNEX A: Levels and effects of radiation exposure due to the nuclear accident after the 2011 great east-Japan earthquake and tsunami (2013)
- 2020 Annual Report by the UNSCEAR:
- SOURCES, EFFECTS AND RISKS OF IONIZING RADIATION UNSCEAR 2020/2021, Report, SCIENTIFIC ANNEX B: Levels and effects of radiation exposure due to the accident at the Fukushima Daiichi Nuclear Power Station: Implications of information published since the UNSCEAR2013Report (2020)
- Included in this reference material on March 31, 2023