A survey conducted in the wake of the nuclear disaster in Fukushima Prefecture reveled that of more than 1,000 children screened, 45 percent of them tested positive for thyroid exposure to radiation, according to a statement by the Nuclear Safety Commission on Tuesday.
The Nuclear Safety Commission, established within the Cabinet of Japan as an independent agency to play the main role in nuclear safety administration, said the tests were conducted on 1,080 children with ages ranging between new borns up to 15 year olds and living in Iwaki, Kawamata and Iitate areas of the prefecture, between March 26-30.
The tests were conducted due to the massive amounts of radiation leaked into the air, sea and ground from the quake and tsunami-damaged Fukushima No. 1 nuclear power plant, following the double-disasters devastating the northeastern coastal regions and pummeling the now crippled plant, which was ill-equiped to handle the ferocity of the tsunami on March 11.
Among children who tested positive for thyroid exposure, the amounts measured 0.04 microsieverts per hour or less in the majority of cases, with the largest exposure being 0.1 microsieverts per hour, equivalent to a yearly dose of 50 millisieverts for a 1-year-old.
Due to none of the children in the relatively small sample group showing exposure over the 0.2 microsieverts per hour benchmark for further investigations, no emergency measures would be taken, officials said.
However, citizens groups said Tuesday that soil samples taken at four locations in Fukushima City on June 26 all tested positive for radioactive cesium contamination, measuring between 16,000 to 46,000 becquerels per kilogram -- far exceeding the legal limit of 10,000 becquerels per kg.
The city is located about 60 kilometers northwest of the crippled nuclear plant and is outside of the mandatory 20-km no-go zone or evacuation centers located closer to the troubled six- reactor nuclear complex.
One location had radioactive contamination levels as high as 931,000 becquerels per square meters and three locations tested had cesium levels at between 326,000 and 384,000 becquerels per square meter.
Experts note that children are far more vulnerable to the harmful effects of radiation disasters than the general population and are more likely to develop cancer in later life because their bodies absorb and metabolize substances differently, and because they are more likely to develop certain cancers, distinct from adults, from such an exposure.
In addition children also are closer to the ground, where radioactive fallout settles.
City officials in the prefecture, located 220 km northeast of Tokyo, have decided to distribute radiation meters to 34,000 children aged between four and 15 living in Fukushima city, to monitor their exposure levels, as concerns mount over the number and severity of the children already exposed to radiation from the leaking nuclear plant still central to the worst nuclear disaster since the 1986 Chernobyl cataclysm.
Underscoring the devastating affects of the Fukushima nuclear crisis, cesium-134 and 137 isotopes were detected in urine tests conducted on 10 children in Fukushima City, located in close proximity to the stricken No. 1 nuclear power plant.
The tests conducted in May by a Japanese civic group and Acro, a French organization specializing in measuring radiation levels, confirmed that all 10 children had been exposed to radiation internally, with 1.13 becquerels of cesium-134 per liter of urine found in one eight-year-old girl sampled and 1.30 becquerels found in the urine of a seven-year-old boy.
In light of the findings, in September tens of thousands of children living in Fukushima city, who already have their outdoor activities at school severely restricted due to ongoing fears of ground and airborne radiation, are to be given dosimeters to constantly measure their exposure to atmospheric radiation, city officials said.