J. SULTANA1*, N. NAHUR2, D. PAUL3 and M. I. ALI4
1=Professor Dr. Jolly Sultana, Department of Physics, Khulna University of Engineering and Technology (KUET), Khulna, Bangladesh, 2Mst. Nur Nahar, MSc Student, Department of Physics, Khulna University of Engineering and Technology (KUET), Khulna and 3 Dr. Debasish Paul, Chief Scientific Officer and Head, Health Physics Division, Atomic Energy Center, Saver, Dhaka Bangladesh. 4Dr. Md. Idris Ali, Chief Scientific Officer, Health Physics Division, Atomic Energy Center, Saver, Dhaka Bangladesh. *Corresponding author’s E-mail: jsa_kuet@yahoo.com
ABSTRACT
The study was conducted at the Department of Physics, Khulna University of Engineering and Technology (KUET), Khulna and Health Physics Division, Atomic Energy Commission Saver, Dhaka, Bangladesh. Paddy samples have been collected from different locations on the Bank of Rupsha River at Rupsha upazila under Khulna district of Bangladesh. In the present study, a total of 6 paddy samples have been collected during April to May 2015. Radioactivity has been determined by using a High Resolution Germanium detector (HPGe) at Health Physics, Atomic Energy Commission Saver, Dhaka, Bangladesh. The samples have been analyzed by gamma-ray spectrometry system using a ‘Hyper-Pure Germanium’ (HPGe) detector to identify the probable radionuclides, activity concentrations and the radiological risks to human from intake of paddy. Natural radionuclides such as 226Ra, 232Th and 40K have been found in the samples and no artificial radionuclide has been detected in any of the sample. The activity concentrations of 226Ra, 232Th and 40K in Paddy samples have been found to be varied from 17.59±4.44 to 42.32±4.48, average 24.43±5.16 Bq/Kg, BDL to 3.745±2.99, average 2.048±2.798 Bq/Kg and 35.97±150.34 to 170.12±135.49, average 93.96±133.75 Bq/Kg respectively. The annual effective doses of all samples have been found that intake high effective dose of 232Th of 248.29 µSv y-1 by paddy samples. These values of doses are much below the permissible level set by ICRP. There is no immediate health risk on workers and public due to natural radioactivity present in the samples of the study area.
Keywords: Natural radionuclides, Paddy, Activity concentrations, Radioactivity level and Harmful.