The plant has been leaking radioactive substances since it was hit by a magnitude-9 earthquake and resulting tsunami on March 11
About 45 per cent of children in Fukushima prefecture experienced thyroid exposure to radiation after the nuclear power there was damaged in March, officials said Tuesday.
But the results were not high enough to require further examination, the Nuclear Safety Commission said.
In late March, local and central governments carried out the survey on 1,080 children under the age of 15 in areas near the damaged Fukushima Daiichi Nuclear Power Station after the crisis.
The plant has been leaking radioactive substances since it was hit by a magnitude-9 earthquake and resulting tsunami on March 11.
Among children who tested positive for thyroid exposure, the amounts measured 0.04 microsieverts per hour or less in most cases, while the largest exposure was 0.1 microsieverts per hour, equivalent to a yearly dose of 50 millisieverts for a one-year-old baby, Kyodo News reported.
None of the children examined was exposed to more than 0.2 microsieverts per hour, the official benchmark for further examinations, Kyodo said citing the commission.
Children and babies are at highest risk of developing thyroid cancer after exposure to radioactive iodine released into the environment.
In the case of 1986 Chernobyl disaster in Ukraine, most victims who developed the cancer in following years had been babies or children living in the affected regions at the time of the world’s worst nuclear accident, Kyodo said.
A survey of soil at four locations in the city of Fukushima, 60 kilometres from the plant, found all samples were contaminated with radioactive caesium, measuring 16,000 to 46,000 becquerels per kilogram, exceeding the official limit of 10,000 becquerels per kilogram, citizens groups said Tuesday.
The city is located far from the 20-kilometre no-go zone around the plant.
The group detected as much as 931,000 becquerels per square metre at one location, above the 555,000-becquerel limit for compulsory resettlement in the Chernobyl disaster. Samples from the other three locations measured between 326,000 and 384,000 becquerels per square metre, Kyodo reported.