Natural radioactivity in soil samples from selected areas in Nineveh governorate, Iraq

Abstract

The activity distribution of natural radionuclides 232Th, 226Ra, 40K and 137Cs were determined in soil samples. The samples were collected from four different regions in Nineveh governorate north-west of Iraq (Tall Kayf, Badush, Al-Hamdaniya, Hammam Al-alil) and measured by the gamma-ray spectrometry with high purity germanium (HPGe) detector with relative efficiency 50 %. The specific radioactive activity of the samples was in the range of 1.75 - 45.56; 8.63 - 43.72; 147.92 - 502.49 and MDL - 69.32 Bq/kg, respectively, at the selected areas. The calculated hazard indices that estimate the potential radiological health risk such as radium equivalent activity (Raeq) were in the range 40.33 - 122.12 Bq/kg. The absorbed dose rate in the air was also calculated for the samples and it was in the range 20.51 - 56.72 nGy/h. External hazard index (Hex) is in the range 0.11 - 0.33, internal hazard index (Hin) is in the range 0.13 - 0.4 and gamma index was 0.32 - 0.89. The annual effective dose equivalent (AEDE), annual gonadal dose equivalent (AGDE), and excess lifetime cancer risk (ELCR) were also calculated and their ranges were 25.15 - 69.56; 151.63 - 396.05 and 0.09·10-3 - 0.24·10-3 respectively. This study showed that there is no radiation hazard to the public due to natural radionuclides in the selected areas.

Keywords

• activity concentrations
• gamma-ray spectrometry
• hazard indices
• natural radioactivity
• hpge detector.