Radionuclides in imported foods consumed in Hokkaido were examined by germanium (Ge) gamma-ray spectrometer system.
The values of radioactive cesium (137Cs+134Cs) concentration of 480 samples collected during 1989-1999 were lower than the temporary limit (370Bq/kg) . These values of 441 samples (92%) were lower than 1 Bq/kg. The maximum values of 137Cs and 134Cs were 62.4Bq/kg, 3.8Bq/kg in black tea imported from China.
From the relation between concentration of 137Cs and cesium unit, the contribution from Chernobyl reactor accident was estimated qualitatively on 24 samples with higher values than 0.40Bq/g-K. Based on the concentration of 134Cs and 137Cs detected in 16 samples, the contribution of 137Cs from this accident were calculated.
Japan Radioisotope Association