At its sixty-fourth session (29 May to 2 June 2017), the Committee recalled its assessment of the exposures and effects due to the nuclear accident after the 2011 great east-Japan earthquake and tsunami, as presented in its report to the sixty-eighth General Assembly in 2013 and the supporting detailed scientific annex 3. It had concluded in that report that, in general doses were low and that therefore associated risks were also expected to be low. A discernible increase in cancer incidence in the adult population of Fukushima Prefecture that could be attributed to radiation exposure from the accident was not expected. Nevertheless, the report noted a possibility that an increased risk of thyroid cancer among those children most exposed to radiation could be theoretically inferred, although the occurrence of a large number of radiation-induced thyroid cancers in Fukushima Prefecture—such as occurred after the Chernobyl accident—could be discounted because absorbed doses to the thyroid after the accident at Fukushima were substantially lower. It had also concluded that no discernible changes in birth defects and hereditary diseases were expected and that any increased incidence of cancer among workers due to their exposure was expected to be indiscernible because of the difficulty of confirming a small increase against the normal statistical fluctuations in cancer incidence. The effects on terrestrial and marine ecosystems were expected to have been transient and localized.
Following its assessment, the Committee put in place arrangements for follow-up activities to enable it to remain abreast of additional relevant information as it was published. The Committee’s reports of the sixty-second and sixty-third sessions to the seventieth and seventy-first sessions of the General Assembly, respectively, included the Committee’s findings from its follow-up activities up to the relevant time in each case.
The Committee has continued to identify further information that had become available up to the end of 2016, and systematically appraised relevant new publications to assess their implications for the Committee’s 2013 report. A large proportion of these new publications have again confirmed the main assumptions and findings of the Committee’s 2013 report. None of the publications have materially affected the main findings in, or challenged the major assumptions of, the Committee’s 2013 report. A few have been identified for which further analysis or more conclusive evidence from additional research is needed. On the basis of the material reviewed, the Committee sees no need, at the current time, to make any change to its assessment or its conclusions. However, several of the research needs identified by the Committee have yet to be addressed fully by the scientific community.
