A study of soil samples conducted by a team of experts from Kyoto University and Hiroshima University has revealed that as much as 400 times the normal levels of radiation could remain in communities beyond a 30-kilometer radius from the Fukushima No. 1 nuclear power plant.The study found cesium-137 at levels between about 590,000 and 2.19 million becquerels per cubic meter.After the Chernobyl nuclear accident in the former Soviet Union in 1986, residents who lived in areas where cesium-137 levels exceeded 555,000 becquerels were forced to move elsewhere.