Measurement of radionuclides and absorbed dose rates in soil samples of Peshawar, Pakistan, using gamma ray spectrometry

摘要

The analysis of gamma-emitting radionuclides in nature, i.e. ~(226)Ra, ~(232)Th, ~(40)K and ~(137)Cs, has been carried out in soil samples collected from Peshawar University Campus and surrounding areas using a high purity germanium detector coupled with a computer-based high-resolution multichannel analyser. The activity concentrations in soil ranged from 30.20 ± 0.65 to 61.90 ± 0.95,50.10 ± 0.54 to 102.80 ± 1.04, 373.60 ± 4.56 to 1082 ± 11.38 and 9.50 ± 0.11 to 46.60 ± 0.42 Bq kg~(-1) for ~(226)Ra, ~(232)Th, ~(40)K and ~(l37)Cs, with a mean value of 45 ± 7.70,67 ± 12.50, 878 ± 180 and 19 ± 9.20 Bq kg~(-1), respectively. The radium equivalent activity, internal and external hazard indices have mean values of 203.40 ±29.40 Bq kg~(-1), 0.56 and 0.68, respectively. The mean values of outdoor and indoor absorbed dose rates in air and the annual effective dose equivalents were found to be 106.50 and 128 nGy h~(-1) and 0.19 and 0.54 mSv y~(-1), respectively. In the present study, ~(40)K was the major radionuclide present in soil samples. The presence of ~(137)Cs indicates that this area also received some fallout from the nuclear accident of the Chernobyl power plant in 1986. The activity concentrations of radionuclides found in soil samples during the current investigation were nominal. Therefore, they are not associated with any potential source of health hazard to the public.