Radioactive cesium has not been detected in 99 percent of people in Fukushima Prefecture, host of the stricken Fukushima No. 1 nuclear plant, and neighboring Ibaraki Prefecture since March 2012, a study showed.
Radioactive cesium has not been detected in 99 percent of people in Fukushima Prefecture, host of the stricken Fukushima No. 1 nuclear plant, and neighboring Ibaraki Prefecture since March 2012, a study showed.
A research team led by Ryugo Hayano, a physics professor at the University of Tokyo, examined internal radiation exposure levels of 30,000 people using a whole-body counter at a hospital in Hirata, Fukushima Prefecture, between October 2011 and November 2012.
The results showed that since March last year, cesium-137 has been detected in only 1 percent of around 20,000 examinees. They changed their clothing before the examination to prevent false positive readings caused by soil on clothes.
Cesium-137 was detected in 0.09 percent of children 15 or younger after March 2012, but the percentage fell to zero after May 2012.
Some experts warn that food contaminated by radioactive materials that spewed into the atmosphere after the meltdowns following the Great East Japan Earthquake on March 11, 2011, can cause extreme internal exposure. If true, radioactive cesium would accumulate in the body, elevating the radiation doses in people aged 20 or older about a year after nuclear disaster started.
But the survey has shown that this has not happened.
The survey results were published in the Internet edition of an English-language