BY MITSURU OBE – “The first comprehensive soil survey from areas around the Fukushima Daiichi nuclear plant showed extensive ground contamination and another report warned of the continued threat to Japan’s food chain, underscoring the major challenges the country still faces in its radioactive cleanup efforts….

Nearly six months after the accident, the education ministry released Tuesday the first comprehensive survey of soil contamination within a 62-mile radius, showing that more than 30 locations spread over a wide area have been contaminated with long-lasting radioactive cesium.

Government officials said the report did not materially alter their prior understanding of the spread and extent of contamination, previously estimated through aerial surveys and above-ground radiation monitoring. They said that the highest-contaminated communities had already been evacuated, and the new data did not justify any change in the evacuation policy.

But the extent of reported contamination does raise new questions about how quickly the communities can be cleaned up, and the dangers of radioactive materials spreading to a wider area through wind or rain.

The survey of 2,200 locations—conduced by 400 researchers in June and July—found that 33 of those locations had cesium-137 in excess of 1.48 million becquerels per square meter, the level set by the Soviet Union for forced resettlement after the 1986 Chernobyl disaster, Japanese authorities said.

Another 132 locations had a combined amount of cesium-137/134 of more than 555,000 becquerels per square meter, the level at which the Soviet authorities called for voluntary evacuation and imposed a ban on farming.” Read more.