Characterization of natural radioactivity in soil of Balad city and its surroundings, Iraq

The main objective of this research is to study the natural radioactivity in soil samples collected fromBalad city and its surrounding area by measuring the concentrations of natural radionuclides for (²³⁸U, ²³²Th, ⁴⁰K) and artificial nuclide ¹³⁷Cs by using gamma ray spectroscopy with NaI(Tl) scintillation detector.The results show that the activity concentration for ²³⁸U in soil ranged from 4.44 to 20.83 Bq/kg with an averages of 8.85 Bq/kg,the activity concentration for ²³²Th in soil ranged from 1.26 to 68.54 Bq/kg with an averages of 27.43 Bq/kg, the activity concentration for ⁴⁰K ranged from 134.45Bq/kg to 680.67 Bq/kg with average 299.57 Bq/kg. The average level of specific activities of 238U,232Th and ⁴⁰K neutral nuclides in soil samples are below the recommended global limits 35, 30 and 400 Bq/kg respectively (UNSCEAR, 2000).The specific activity for artificial nuclide 137Cs in soil sample recorded lowest value 0.23 Bq/kg and the highest value 4.03 Bq/kg with average 1.37 Bq/kg. The average level of specific activity of ¹³⁷Cs nuclide in soil samples are below the recommended global limits 14.8 Bq/kg (UNSCEAR, 2000). The radiological hazard indices were found to be within the recommended global International Commission on Radiological Protection recommended limits. (author)