Contribution of environmental radionuclides to radiological hazard effects due to surface soils collected from Amman Governorate, Jordan

The environmental radioisotopes concentrations of some specimens of surface soil from Amman Governorate, Jordan have been analyzed using an HPGe- detector to check the contributions of environmental radioisotopes to the radiation hazard effects. The activity concentrations were estimated for ²²⁶Ra (range from 12.9 ± 1.0 to 58.9 ± 4.6 Bq/kg), ²³²Th (range from 8.2 ± 1.0 to 68.9 ± 5.6 Bq/kg), and ⁴⁰K (range from 142.9 ± 15.2 to 347.4 ± 31.5 Bq/kg). Average values of radium equivalent activities (Ra_eq), absorbed dose rate (DR), the annual effective dose rate (HR), the internal hazard index (H_in), and external hazard index (H_ex) were calculated to be 102.02 Bq/kg, 46.54 nGy/h, 0.056 mSv/y, 0.352 and 0.275 respectively. It was noticed that all values of Ra_eq are among the permissible value (370 Bq/kg). The radiological implication in working site has shown that most of the soil samples have a dose rate less than the world recommended value except soil samples from two locations (S9 and S11). From the results, one can see that total annual effective dose, that a person can absorb from soils located in his place for all sample locations is below the accepted value (1.0 mSv/y).The H_in and H_ex values were within the standard values. From the analysis carried out in this study, ²³²Th-radionuclides was found to be the main contributor to the environmental radionuclides for most discussed radiological hazard effects