Assessment of dose due to natural radio-nuclides in vegetables of high background radiation area in south-eastern part of Bangladesh

Background: The aims of the study are to determine the radioactivity concentrations of 226Ra, 238U, 232Th and 40K in vegetables of a recently found high background radiation area of south-eastern part of Bangladesh and to detect the radiological risks to human from intake of these vegetables. Materials and Method: 10 plant samples were collected randomly from different locations of the study area. The radio-nuclides in papaya were measured by direct &gamma-ray spectrometry using HPGe detector. Results: The average activity concentrations of 226Ra, 238U, 232Th and 40K in papaya samples were 80.95±13.61, 64.77±38.47, 83.53±20.50 and 1691.45±244.98 Bq kg-1 respectively. The annual effective ingestion dose due to intake of papaya was 1.1 mSv Y-1. Conclusion: The concentrations of radio-nuclides in the papaya samples found in present study were higher than the world average values suggested by the UNSCEAR. The annual effective ingestion dose was found 3.8 times higher than total exposure per person resulting from the ingestion of terrestrial radioisotopes.