Assessment of environmental radioactivity in soil samples of primary schools in North of Al-Najaf governorates

Background : Natural radioactivity in the soil is the main reason behind this research. So, the natural radioactivity ( 40 K, 238 U, and 232 Th) in soil samples have been measured in ten primary schools at north of Al - Najaf province. Materials and Methods : The specific activities ( 214 Bi belongs to the uranium - 238 series; 208 TI belongs to the thorium - 232 string and a natural radionuclide 40 K) have been indicated by using spectral analysis technique of Gamma - ray of 3”x3” NaI(Tl) scintillation detector has been used. Results : The average value of specified activity for 40 K, 238 U, and 232 Th in all samples is (201.47±24.47) Bq/kg, (10.17±1.78) Bq/kg, and (5.91±0.83) Bq/kg respectively. In this work, the majority of the hazard indices were calculated. The average value of radium Equivalent Activity was (16.673±1.71) Bq/kg, Absorbed Gamma Dose was (16.673±1.71) nGy⁄h, external hazard index was (0.092±0.009), internal hazard index was (0.120±0.013), representative gamma index was (0.261±0.026), Annual influential dose equivalent indoor was (0.082±0.008), for Annual influential dose equivalent outdoor was (0.020±0.002) mSv/y, and excess lifetime cancer risk was (0.358±0.03) × 10 - 3 . Conclusion : Most of the detected readings are in the recommended values by (UNSCEAR, OECD, and ICRP) When compared with the worldwide average ( 40 K=412 Bq/kg, 238 U=35 Bq/kg, and 232 Th= 45 Bq/kg). In other words, ten primary schools at Al Najaf governorates are safe for work and free of radiation hazards to students.