Comparison levels of natural radioactivity for some of agriculture and virgin soil in the Najaf governorate

Abstract

Specific activities of the natural radionuclides 238U,232Th and 40K have been measured by gamma –ray spectrometry NaI(Tl) in twenty virgin and agriculture soil samples from Najaf governorate. The range of specific activity of 238U, 232Th and 40K in the virgin soil samples varies from 16.08±4.71 to 37.79±4.16 Bqkg-1, 8.83±3.52 to 42.36±2.33Bqkg-1 and 127.91±11.21 to 756.09±11.14 Bqkg-1 with average values of 27.39±4.46 Bqkg-1, 31.16±3.00 Bqkg-1 and 602.77±10.76 Bqkg-1 respectively, whereas for agriculture soil samples varies from 29.90±5.99 to 78.58±5.50 Bqkg-1 , 26.87±2.98 to 59.31±3.41 Bqkg-1 and 543.64±10.98 to 1104.61±12.23 Bqkg-1 with average values of 51.96±5.04 Bqkg-1, 42.48±3.47 Bqkg-1 and 847±11.26 Bqkg-1 respectively. The radium equivalent activity (Raeq), the absorbed dose rate (D) and the activity concentration index (Iγ) resulted from the natural radionuclides in soil, were also calculated. All values of Raeq were lower than the worldwide average. The average values of (D) and (Iγ) in all soil sample were higher than the permissible limit.