The Malaysian Journal of Analytical Sciences Vol 12 No 1 (2008): 195 – 204

 

 

AN ASSESSMENT OF ABSORBED DOSE AND RADIATION HAZARD INDEX FROM NATURAL RADIOACTIVITY

 

Masitah Alias¹, Zaini Hamzah¹, Ahmad Saat¹, Mohamat Omar² and Abdul Khalik Wood²

 

¹Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor Darul Ehsan

²Malaysian Institute for Nuclear Technology Research, 43000, Bangi, Selangor Darul Ehsan

 

Abstract

Naturally occurring radionuclides such as ⁴⁰K, ²²⁶Ra and ²²⁸Ra which emit gamma radiation through their decaying process could reach the human in vicinity. The study area was chosen for its variety of surface conditions such as slope, flat land catchments and also forest area, which is used as a reference place. Soil samples were collected using hand auger, and the sampling positions were determined using a Global Positioning System (GPS). The amount of radioactivity concentration of these radionuclides is the important factor in assessing whether it is harmful or otherwise. In this study, the surface doses rate measurements were done in-situ using dose rate meter, and the radioactivity concentration levels were done by counting the soil  samples  using  gamma  spectrometer  with HPGe  detector  in the  laboratory.  The  amount  of  uranium,  thorium  and potassium in soil were determined using neutron activation analysis (NAA) technique. The results show a reasonably low radiation absorb dose and radiation hazard index, which is a good indication for the farmers to work in the area.

 

Keywords: Natural radionuclides, absorbed dose rate, radiation hazard index, gamma spectrometer, NAA.

 

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