Investigation of natural radioactivity in the soil of Kufa zone , Najaf

Abstract

The natural radioactivity due to presence of 238U, 232Th and 40K radionuclides in soil of Kufa zone , Najaf governorate, Iraq were measured by using gamma-ray spectrometry NaI(Tl) "3× 3". The specific activity of the soil samples ranged from 1.76±2.30 to 77.45±2.35 Bqkg-1 with an average of 25.23±2.94 Bqkg-1, from 7.92±1.22 to 42.58±1.75 Bqkg-1 with an average of 20.09±1.11 Bqkg-1 and from 219.58±1176 to 1994.17±16.15 Bqkg-1 with an average of 984.30±11.86 Bqkg-1 for 238U, 232Th and 40K respectively. The study also examined some radiation hazard indices such as radium equivalent activity (Raeq), Absorbed Dose rates (D), External Hazard Index (Hex) and Internal Hazard Index (Hin). These calculated hazard indices to estimate the potential radiological health risk in soil. The radium equivalent activity (Raeq) values found to vary from 67.80 to 285.80 Bqkg-1, with the average value of 129.74 Bqkg-1, which was less than permitted value (370 Bqkg-1). The absorbed dose rates, ranged from 32. 1 to 142.08 nGyh-1, with a average value of 65.17 nGyh-1 that higher than the permissible limit of 55 nGyh-1. The external and internal hazard index of soil samples were less than unity