Radioactivity Levels and Gamma-Ray Dose Rate in Soil Samples from Kohistan （Pakistan） Using Gamma-Ray Spectrometry

• Published in: Chinese physics letters 2011, Vol.28 (1), p.226-229
• Main Author: Hasan M. Khan M. Ismail K. Khan P. Akhter
• Format: Article
• Language: English
• Subjects: γ射线; 伽玛射线; 光谱法; 剂量率; 土壤样品; 天然放射性核素; 巴基斯坦; 放射性水平
• ISSN: 0256-307X; 1741-3540

The analysis of naturally occurring radionuclides （226Ra, 232 Th and 40 K） and an anthropogenic radionuclide 13r Cs is carried out in some soil samples collected from Kohistan district of N.W.F.P. （Pakistan）, using gamma-ray spectrometry. The gamma spectrometry is operated using a high purity Germanium （HPGe） detector coupled with a computer based high resolution multi channel analyzer. The specific activity in soil ranges from 24.72 to 78.48Bq.kg-1 for 22TRa, 21.73 to 75.28Bq.kg- 1 for 232Th, 7.06 to 14.9Bq.kg 1 for 1arcs and 298.46 to 570.77Bq.kg-1 for 40K with the mean values of 42.11, 43.27, 9.5 and 418.27Bq.kg-1, respectively. The radium equivalent activity in all the soil samples is lower than the safe limit set in the OECD report （370 Bq.kg-1）. Man-made radionuclide 13r Cs is also present in detectable amount in all sell samples. Presence of 13r Us indicates that the samples in this renlote area also recelvo some fallout from nuclear accident in Chernobyl power plant in 1986. The internal and external hazard indices have the mean values of 0.48 and 0.37 respectively. Absorbed dose rates and effective dose equivalents are also determined for the samples. The concentration of radionuclides found in the soil samples during the present study is nominal and does not pose any potential health hazard to the general public.