Recent data collected by Prof. Tetsuji Imanaka of Kyoto University Research Reactor Institute, in the Magata area of Iidate (40 km from the power plant) showed cumulative radiation levels as high as 95 millisieverts. Japan’s Nuclear Safety Commission guidelines require people to take shelter in concrete buildings or evacuate when cumulative levels reach over 50 millisieverts of radioactivity.
Soil testing by Prof. Imanaka’s team in Iidate revealed levels of radioactive Iodine-131 as high as 3,260 kilobecquerels (kBq) per square meter, and levels of Cesium-137 (with a 30 year half-life) at 2,200 kBq. By comparison, Prof. Imanaka says that the index used to evacuate citizens out of a 30km radius around Chernobyl was 1,480 kBq/square meter.
Meanwhile, Fukushima Prefecture measured the radiation levels at all its elementary and junior high schools on April 5-7. Results showed that over 75% of the monitored schools had radiation levels above the legal standard for a “radiation controlled area” – defined as an area where unnecessary human entry and radioactive exposure are to be prevented and avoided. Over 20% of the schools saw even higher radiation levels warranting “individual exposure control.” However, elementary and junior high schools in the area commenced the new semester on April 5, in spite of the greater health risks and vulnerability of children to radioactive exposure.
http://fukushima.greenaction-japan.org/2011/04/21/antoyo-keizai-online-reports-serious-radioactive-contamination-levels-beyond-the-30km-evacuation-radius-around-the-fukushima-nuclear-plant/