en Radiation Biology Radiation Biology گزارش کوتاه Short Report <p></p> <p>To assess the environmental radioactivity levels and hence to determine the population exposure in Kutubdia Island, Bangladesh the sediment samples were analyzed by using gamma ray spectrometry. In those sediment samples the average activity concentration of natural radionuclides ²³⁸U, ²³²Th and ⁴⁰K were found 15.39&plusmn;1.67, 38.35&plusmn;0.76 and 475.51&plusmn;21.15 Bq/kg respectively. The activity concentration of ²³⁸U and ²³²Th were less than the world average. But the activity concentration of ⁴⁰K was higher than the world average values. These results were used to calculate the radiological hazard parameters like radium equivalent activities (Ra_eq), representative level index (I_&gamma;_r). Due to natural radionuclides in sediment, the effective 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 activities (Ra_eq) and representative level index (Igr) were found to be 128.03&plusmn;12.08 Bq/Kg and 0.96&plusmn;0.09 Bq/Kg which were greater than the world average. The anthropogenic radionuclide ¹³⁷Cs was also found in few samples. The average activity concentration of ¹³⁷Cs was 1.64&plusmn;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 population exposure from radionuclides in sediment as well as base line data of natural radioactivity in this island.</p> <p></p> Keywords: Natural radionuclides, HPGe gamma-spectrometry, radium equivalent activity, representative level index, annual effective dose. 373 377 http://ijrr.com/browse.php?a_code=A-10-1-642&slc_lang=en&sid=1 Q.M. Rashed-Nizam 7900319475328460010023 7900319475328460010023 Yes Department of Physics, University of Chittagong, Chittagong-4331, Bangladesh M. Rahman 7900319475328460010024 7900319475328460010024 No Department of Physics, University of Chittagong, Chittagong-4331, Bangladesh M.K. Tafader 7900319475328460010025 7900319475328460010025 No Institute of Marine Science, University of Chittagong, Chittagong -4331, Bangladesh M. Zafar 7900319475328460010026 7900319475328460010026 No Institute of Marine Science, University of Chittagong, Chittagong -4331, Bangladesh A.K.M.S.I. Bhuian 7900319475328460010027 7900319475328460010027 No Radioactivity Testing and Monitoring Laboratory, Bangladesh Atomic Energy Commission, Chittagong Medical College Campus, Chittagong, Bangladesh R.A. Khan 7900319475328460010028 7900319475328460010028 No Radioactivity Testing and Monitoring Laboratory, Bangladesh Atomic Energy Commission, Chittagong Medical College Campus, Chittagong, Bangladesh M. Kamal 7900319475328460010029 7900319475328460010029 No Radioactivity Testing and Monitoring Laboratory, Bangladesh Atomic Energy Commission, Chittagong Medical College Campus, Chittagong, Bangladesh M.I. Chowdhury 7900319475328460010030 7900319475328460010030 No Radioactivity Testing and Monitoring Laboratory, Bangladesh Atomic Energy Commission, Chittagong Medical College Campus, Chittagong, Bangladesh M.N. Alam 7900319475328460010031 7900319475328460010031 No Radioactivity Testing and Monitoring Laboratory, Bangladesh Atomic Energy Commission, Chittagong Medical College Campus, Chittagong, Bangladesh