2 Apr (NucNet): Cancer levels are likely to remain stable in the wake of the 2011 Fukushima-Daiichi nuclear power accident and there will be no increase in the rates of birth defects, according to a new UN report released today.
The report, by the United Nations Scientific Committee on the Effects of Atomic Radiation (Unscear), finds that “no discernible changes in future cancer rates and hereditary diseases are expected” due to exposure to radiation as a result of the accident.
Nevertheless, it notes a “theoretical possibility” that the risk of thyroid cancer among the group of children most exposed to radiation could increase and concludes that the situation needs to be followed closely and further assessed in the future. Thyroid cancer is a rare disease among young children, and their normal risk is very low.
The findings are based on estimates of the exposure of various population groups – including children – as well as scientific knowledge of health impacts following radiation exposure.
Unscear chairman Carl-Magnus Larsson said based on the findings, Unscear does not expect significant changes in future cancer statistics that could be attributed to radiation exposure from the accident.
According to the report, the expected low impact on cancer rates of the population is largely due to prompt protective actions on the part of the Japanese authorities following the accident.
A report published in May 2013 by the Nuclear Energy Agency said the quick evacuation of 78,000 people living within 20 km of the nuclear station and the sheltering of those living between 20 and 30 km from the station meant that “health-significant population exposures” were avoided following the accident.
Unscear analysed reported worker doses and also independently assessed doses for some of the workers. The committee’s assessments are broadly consistent with reported doses, but uncertainties remain for exposures during the early phase of the accident.
The committee also evaluated the effects of radiation exposure on both terrestrial and marine ecosystems, finding that any effects would have been transient.
For marine ecosystems, the possibility of effects on flora and fauna was limited to the shoreline area next to the power station and the potential for effects over the long term was considered insignificant.
The report says the March 2011 earthquake and subsequent tsunami, which flooded over 500 square kilometres of land, resulted in the loss of more than 20,000 lives and destroyed property, infrastructure and natural resources. They also led to the worst civil nuclear disaster since the one at Chernobyl in 1986.
The loss of offsite and onsite electrical power and compromised safety systems at the Fukushima-Daiichi nuclear power station led to severe core damage to three of the six nuclear reactors on the site. This resulted in the release, over a prolonged period, of very large amounts of radioactive material into the environment.
The report, titled ‘Levels and effects of radiation exposure due to the nuclear accident after the 2011 great east-Japan earthquake and tsunami’, is online:
www.unscear.org/docs/reports/2013/13-85418_Report_2013_Annex_A.pdf
