RESUMO
Objective:To investigate the radionuclide concentrations in rice and corn in some areas of Yunnan province, and enrich the baseline data on radioactivity level in food in Yunnan province, and assess the health risks to residents.Methods:The samples of rice and corn collected from 20 counties in Yunnan province were determined by using gamma spectrometer under the national standards Gamma Spectrometry Method of Analysing Radionuclides In Biological Samples (GB/T 16145-1995), General Analytical Method of High-Purity Germanium Gamma Spectrometer (GB/T 11713-2015), Examination of Radioactive Materials for Foods- General Principle (GB 14883.1-2016) and Determination of Radionuclides in Soil by Gamma Spectrometry(GB/T11743-2013). The results were compared and evaluated.Results:The average activity concentrations in rice were found to be 238U (0.416±0.403) Bq/kg, 32Th (0.045±0.034) Bq/kg, 226Ra (0.030±0.013) Bq/kg, 40K (28.4±18.8) Bq/kg and 137Cs (0.014±0.019) Bq/kg, respectively, and in corn to be 238U (0.308±0.230) Bq/kg, 232Th (0.035±0.031) Bq/kg, 226Ra (0.053±0.072) Bq/kg, 40K (56.8±38.6) Bq/kg, respectively. The specific activities of the 137Cs were lower than the detection lower limit. Conclusions:The radionuclide concentration of 238U, 232Th, 226Ra, 40K and 137Cs in rice and corn in 20 counties of Yunnan province meets the national standards. The dose burden to the public will not affect human health.