Estimation of the Intake of Radioactive Cesium Based on Analysis of Total Diet Samples in Nagoya

Food samples were purchased in Nagoya based on daily intake in the Tokai region, and prepared as total diet samples according to the market basket method. The contents of radioactive cesium (Cs) were determined by using a gamma-ray spectrometer with a germanium semiconductor detector, and a committed effective dose was estimated. Radioactive Cs was not detected in samples collected in 2006 before the Fukushima nuclear plant accident. Radioactive Cs was detected in samples prepared in August, 2011, five months after the accident. The sources were sugar and confectioneries (3rd food group), other vegetables, seaweeds and mushrooms (8th food group) and fishes, shellfishes and processed seafoods (10th food group). Only Cs-137 was detected in samples prepared in August, 2012, one year and five months after the accident. The sources were the 8th and the 10th food groups. The estimated committed effective dose for radioactive Cs was 0.0015 mSv in 2011 and 0.00016 mSv in 2012.