Japan: The Ministry of Education, Culture, Sports, Science and Technology in Japan released updated soil radiation maps. The maps show broader swath of Japan than previous releases, covering six new prefectures. The newly included prefectures are Iwate, Yamanashi, Nagano, Shizuoka, Gifu, and Toyama.
According to the maps, areas contaminated with 30,000 to 100,000 becquerels of radioactive cesium per square meter were found in the municipalities of Ichinoseki and Oshu in Iwate Prefecture, Saku, Karuizawa, and Sakuho in Nagano Prefecture, Tabayama in Yamanashi Prefecture and elsewhere.
The measurements were taken by helicopter and combine contamination with both cesium-134 and -137, which have half-lives of two and 30 years, respectively.