15 Months After Triple Catastrophe in Japan: Earthquake, Tsunami and Fukushima Disaster:
A preliminary report from the World Health Organisation (WHO) published this Wednesday has indicated that radiation levels in most of Japan are low. This news comes a year after the Fukushima accident, which led to pressure on the government to switch off all nuclear reactors in Japan. On 5th May 2012 Japan switched off its last remaining nuclear reactor, leaving the country without nuclear-derived electricity for the first time in over 40 years.
The WHO report follows the 2011 Tōhoku earthquake which caused a 13-15m tsunami that flooded the Fukushima-Daiichi nuclear power station. After the plant’s cooling systems failed, blasts occurred at four of the reactors, triggering radiation leaks. Thousands of people were evacuated from the surrounding area.
Now, one year on from the disasters, the WHO report has found that Namie town and Itate village, near the Fukushima plant, are currently exposed to radiation doses of 10-50 millisieverts (mSv). This is up to 20 times the normal background radiation level, although it remains within the WHO’s recommended emergency limits. However, in some areas of Namie, infants were estimated to have gotten a dose as high as 200mSv in the thyroid, where radiation can build up in the body.
By comparison, the rest of Fukushima is exposed to radiation doses of 1-10 mSv in the and most of Japan as a whole sees radiation levels of 0.1-1mSv. This is within the limits of the International Commission on Radiological Protection.
Not a lot is known about the potential long-term health effects of continued exposure to radiation below 100mSv a year. Cumulative exposure to 100 mSv is said however to raise the risk of death from cancer slightly (by 0.5 percent), according to Japan’s National Institute of Radiological Sciences.
Recently Japan’s trade minister, Yukio Edano, has been trying to win public support to restart two switched-off reactors at the country’s Ohi nuclear plant. This is an attempt to help ease expected power shortages of nearly 20% this summer. It remains to be seen whether this proposal for reactivation will go ahead. It is currently being considered by the Japanese government, although it seems unlikely to gain public approval.
The WHO is currently waiting for a second report on radiation levels this summer.