A National Institute of Radiological Sciences employee shows reporters how to test the thyroid gland dose of internal radiation in 2011. (Asahi Shimbun file photo)
by Yuri Oiwa / The Asahi Shimbun / July 11, 2012 /
Children in Fukushima Prefecture likely received thyroid gland doses of internal radiation, despite earlier government assurances that the levels of such doses were zero, according to an independent study.
The estimated lifetime radiation doses among the children are still low, but they do exist, the National Institute of Radiological Sciences (NIRS) said at an international symposium in Chiba Prefecture on July 10.
The findings run counter to the government’s assertion that they effectively received zero thyroid gland doses.
However, the government has no plans to notify the children’s parents of the latest analysis results, citing their large error margins and the fear of causing anxiety.
“Researchers derived them for scientific purposes,” a government source said. “We have no plan, now or in the future, to notify individuals of their doses.”
The government measured the hourly thyroid doses of 1,080 children under 16 years old in Fukushima Prefecture from March 24 to 30 last year, shortly after a disaster began to unfold at the Fukushima No. 1 nuclear power plant on March 11.
Five months later, the government’s Nuclear Emergency Response Headquarters told the parents of 55 percent of the children that they had zero internal thyroid doses, which included doses below the detection limit of the testing equipment.
A team of researchers led by Toshikazu Suzuki, a section head at the NIRS Research Center for Radiation Emergency Medicine, conducted an independent study of the same measurement data.
The team estimated the lifetime thyroid doses of the 1,080 children at 12 millisieverts on average and 42 millisieverts at the maximum.
CONTINUE READING