Radiation Protection and Environment

: 2013  |  Volume : 36  |  Issue : 3  |  Page : 143--144

Unscear 2013 Report

PP Haridasan 
 IAEA, Vienna, Austria

Correspondence Address:
P P Haridasan
IAEA, Vienna

How to cite this article:
Haridasan P P. Unscear 2013 Report.Radiat Prot Environ 2013;36:143-144

How to cite this URL:
Haridasan P P. Unscear 2013 Report. Radiat Prot Environ [serial online] 2013 [cited 2021 May 9 ];36:143-144
Available from: https://www.rpe.org.in/text.asp?2013/36/3/143/137601

Full Text

The United Nations Scientific Committee on the Effects of Atomic Radiation at its 61 st session discussed in detail two scientific documents pertaining to the assessment of the levels and effects of radiation exposure due to the nuclear accident after the 2011 Japan earthquake and tsunami. Data from many other sources including the data provided by the Government of Japan and other United Nations Member States, FAO, IAEA, CTBTO, WMO and WHO were also discussed. The detailed analysis of the data is presented in the above 321-pages UNSCEAR Report.

Effective dose to Fukushima Daiichi nuclear power station workers, emergency personnel, municipal workers and volunteers, and the doses to different groups of the public in Fukushima - for adults, children and infants; with different food habits and behavior were estimated. The health implications, including any increased risk of cancer to the exposed were examined through extensive health survey of the population groups. Radiation exposures and effects on nonhuman biota were also estimated to evaluate any associated effects.

For those people who were not evacuated, the highest district-average effective doses received by those living in Fukushima City, in the 1 st year were 4.3 mSv for adults and 7.5 mSv for 1-year-old infants.

In general, for the majority of people in Japan, the additional radiation doses received in the 1 st year following the radioactive releases from the accident were less than the annual background radiation dose of 2.1 mSv. For those residents who were evacuated in the 1 st day after March 11, 2011, the estimated settlement-average total effective doses to adults in the 1 st year were on average <6 mSv and for those who were evacuated at later times, the estimated settlement-average total effective doses to adults in the 1 st year were on average <10 mSv.

The estimated settlement-average absorbed doses to the thyroid of 1-year-old infants in the 1 st year ranged from about 15 mGy to about 80 mGy, which is significantly higher than the average annual absorbed doses (of the order of 1 mGy) to the thyroid from naturally occurring sources of radiation.

The actions taken by the authorities to protect the public significantly reduced the radiation exposures that could have been received otherwise. This was particularly the case for settlements within the 20-km evacuation zone and the deliberate evacuation zones, where the protective measures reduced the potential exposures in the 1 st year by up to a factor of 10. The Committee estimated that effective doses thus averted ranged up to 50 mSv for adults; the absorbed doses to the thyroid of 1-year-old infants averted by evacuation ranged up to about 750 mGy (Extracts from the UNSCEAR 2013 Report, Vol. 1, Scientific Annex A, 2014).