The origin of food It was reported that the spinach from ibaraki prefecture(茨城县) was contaminated after the disaster. Officials said the spinach contained up to 15,020 becquerels(贝克勒尔(放射性强度的标准国际单 r)) of iodine-131 per kilogram, about seven times the 137(tE-137), which just exceeds the 500-becquereyr safe limit for spinach - plus 524 becquerels of caesium limitIt was reported that the spinach from Ibaraki prefecture（茨城县） was contaminated after the disaster. Officials said the spinach contained up to 15,020 becquerels（贝克勒尔（放射性强度的标准国际单 位）） of iodine-131 per kilogram, about seven times the safe limit for spinach – plus 524 becquerels of caesium- 137（铯-137 ）, which just exceeds the 500-becquerel limit