Agricultural Research Management Information System

Home
Research Summary
Search
About Us
- ARMIS
- Brochure
Contact Us
Report
User Request
Data Input
Help
- Operation Manual
  - PDF
  - Video
- Program Area & Commodity
We have reached 37600 number of research entries at this moment.

- Logout

Research Detail

Home
Research
Detail

Investigation of and Naturally Occurring Radionuclides in Soil Samples of Kurigram District, Bangladesh

M. S. Sultana
Department of Natural Science, Varendra University, Rajshahi, Bangladesh

A. Rahim
Faculty of Science and Engineering, North Bengal International University, Rajshahi, Bangladesh

J. Ferdous*
* Health Physics Division, Atomic Energy Centre, Dhaka, Bangladesh

A. Begum
Bangladesh Atomic Energy Commission, Dhaka, Bangladesh

M. A. Islam
Department of Physics, University of Rajshahi, Bangladesh

Abstract/ Executive Summary:

The purpose of this study is to investigate the Anthropogenic and Naturally Occurring Radionuclides in Soil Samples of Kurigram District in Bangladesh. The level of radioactivity in collected soil samples was determined by means of a gamma-ray spectrometry. The observed radioactivity of 238U, for all samples varies from 13±3 to 70±6 Bqkg-1, 232Th ranges from 17±4 to 182±8 Bqkg-1 and 40K ranges from 44±22 to 895±43 Bqkg-1. The radioactivities of 238U, 232Th and 40K were compared with the reported values of other locations of Bangladesh and other parts of the world. Raeq ranges from 117 to 178 Bqkg-1. The estimated Absorbed Dose Rate based on soil radioactivity ranges from 54 to 82 n Gyh-1. Hex varies from 0.32 to 0.48 m Svy -1. The outcomes of this study show that the Hex values from all soil samples are below the permissible limit which is recommended by International Commission of Radiological Protection (ICRP) 60. The Deff from outdoor was estimated in this study varies from 66 to 101 µSvy-1 with average value of 83 µ Svy-1, which is slightly larger than the effective dose of 70 µSvy-1. The radioactivity of natural occurring radionuclides in soil samples of Kurigram poses no threat to general public there. Artificial radionuclide 137Cs was not found in this studied.

Keywords: Soil, Activity Concentration, Radiological Hazard Parameters, Gamma-Ray Spectrometry System, Kurigram District

Location: Kurigram District, Bangladesh

Start Date:

End Date:

Program Area: Risk Management in Agriculture

Commodity: Pollution, Heavy metal in soil

Objectives:

The purpose of this research is first to determine the radioactivity of anthropogenic and natural occurring radionuclide in soil samples from various locations of Kurigram and second, to assess the gamma exposure rates to establish baseline concentrations of radionuclides occurring in soil samples throughout Kurigram.

Methodology:

2.1. Area of Study Bangladesh is located at 88⁰01' E-92⁰41'E longitude and latitude 20⁰34’N-26⁰38’N which is geographically downward to India. Bangladesh is surrounding by the rivers and the source of the rivers in India. Some rivers are situated in Nepal, Bhutan and flown through India. Therefore its land might be contaminated by radioactive sources from upstream. In this present study, the soil samples are collected from most significant regions of Kurigram in Bangladesh. The number of Upazilla (sub district) in Kurigram district is 9, named- KurigramSadar, Ulipur, Chilmary, Nageshary, Vurungamari, CharRajibpur, Roumari, Rajarhat and Fulbari.

2.2. Sample Collection and Preparation Fifty one soil samples from seventeen locations of five upazilas of Kurigram, Bangladesh were collected in January 2014. Three soil samples were collected at 0-5cm, 5cm-10cm and 10-15cm depth from one place and each of the soil samples weighed approximately 1kg. The samples were packed in dried bags which were labeled with sample codes and sealed. Then the samples were moved to the radiation detection laboratories of the health physics division (AEC), Bangladesh. The samples were dehydrated at 105⁰C - 110⁰C and it was ensured that any significant moisture was removed from the samples. Each of the samples was grinded separately and kept into container.. The mass of the samples varied because of the varying density of the sample material. The containers were then labeled properly and sealed tightly, rapped with thick vinyl tapes around their screw necks. The samples were stored for at least four weeks to get ready for measurements.

2.3. Experimental Procedure Every soil sample was measured with a gamma-ray counting system, a high resolution High Purity Germanium coaxial detector (EG&G ORTEC) coupled with a SilenaEmcaplus Multichannel Analyzer (MCA) and associate microprocessors. The effective volume of the detector was 83.47 cm³ and energy resolution of the detector was 1.69 keV at 1332 keV energy with a relative efficiency of 19.6%. The detector was shielded with copper ring (2 mm) at the side and lead (76.2 mm) at the side and the top for reducing the background radiation level. Then the sample was located on the detector for counting. The efficiency of the detector for different radionuclides were identified by standard source Eu-152 and different energies such as 122, 245, 344, 411, 444, 779, 963, 1086, 1112 and 1408 keV (figure.5&6) supplied by Health Physics Division, Atomic Energy Centre, Dhaka (AECD). The radioactivity of238U and 232Th were determined from the average concentration of nuclides [214Pb (295.2keV), 214Pb (351.9keV), 214Bi (609.3keV) and 214Bi (1120.2keV)] and [212Pb (238.6keV), 208Tl (583.1keV), and 228Ac (911.2keV), 228Ac (968.9keV)] respectively. The radioactivity of 40K was determined directly by the gamma-ray transitions at 1460.8keV.

Source of Information: Noble International Journal of Scientific Research Vol. 1, No. 1, pp: 18-29, 2017

Article Link (Online Journal):

Funding Source:

Budget:

Total Budget (Tk.) :

Achievement/Findings:

The radioactivity of the naturally occurring radionuclides 238U, 232Th and 40K and that of artificial radionuclide 137Cs in 51 soil samples from different Upazilas in Kurigram have been studied for the first time. The radioactivity of 238U and 232Th is, in general, similar to those in most districts in Bangladesh except in Sylhet, Rangpur and Lalmonirhat. The radioactivity of 40K in the soil samples of the present study is almost similar to that of all other districts in Bangladesh except Kuakata, Rangpur and Lalmonirhat. The 238U concentration is comparable with most of other countries of the world. The 232Th concentration is higher than that of most other countries. The 40K concentration is comparable with that of most countries. No 137Cs are found in the samples of the present study. The Radium Equivalent Activity Raeq due to the radionuclides in the samples has been estimated. This value is found to be about 2 times less than the permissible maximum value of 370 Bqkg-1. The Absorbed dose rate D estimated from the soil activity is slightly greater than the worldwide mean value 57 nGyh-1. The External Hazard Index Hex of the region is found to be 0.40 which is much below the maximum limit of unity. The Effective Dose Equivalents Deff is found to be 83 μSvy-1, which is slightly greater than the world average. The natural radioactivity in Kurigram poses no health hazards to the population there.

Knowledge Management: Journal