Radiological risk analysis of sediment from Kutubdia island, Bangladesh due to natural and anthropogenic radionuclides

To assess the environmental radioac vity levels and hence to determine the popula on exposure in Kutubdia Island, Bangladesh the sediment samples were analyzed by using gamma ray spectrometry. In those sediment samples the average ac vity concentra on of natural radionuclides 238 U, 232 Th and 40 K were found 15.39±1.67, 38.35±0.76 and 475.51±21.15 Bq/kg respec vely. The ac vity concentra on of 238 U and 232 Th were less than the world average. But the ac vity concentra on of 40 K was higher than the world average values. These results were used to calculate the radiological hazard parameters like radium equivalent ac vi es (Raeq), representa ve level index (Iγr). Due to natural radionuclides in sediment, the effec ve annual outdoor dose in the study area was 0.07 mSv; which is within the accepted range of 0.07 mSv. The average value of radium equivalent ac vi es (Raeq) and representa ve level index (Igr) were found to be 128.03±12.08 Bq/Kg and 0.96±0.09 Bq/Kg which were greater than the world average. The anthropogenic radionuclide 137 Cs was also found in few samples. The average ac vity concentra on of 137 Cs was 1.64±0.20 Bq/kg which is lower than the world average. The obtained experimental data of this research work would be useful to assess the popula on exposure from radionuclides in sediment as well as base line data of natural radioac vity in this island.