Determination of natural radioactivity by gamma spectroscopy in Balad soil, Iraq

The specific activity of naturally and man_maderadionuclides in soil was measured in 30 different locations in Balad city, Salahadeen Governorate, Iraq. The mean of these specific activities of Bi,Ac,Kand Cs in soil were found to be 0-5.2234,0-8.7271,101-1216.83,0-1.4320 Bq.kg respectively. The radium equivalent activity was calculated and it was range from 107.788 Bg/kg to 1219.472 Bg/kg. The absorbed dose rate in air was also calculated for the samples and its range from 6.949nGyh to 51.526nGyh. The outdoor annual effective doses ranged from 0.0085mSv to 0.06319mSv with an average value of 0.0215mSv and the indoor annual effective doses ranged from 0.0340mSv to 0.2601mSv with an average value 0.0861mSv for one year. The external and internal hazard indices were found to be less than 1, indicating a low dose. The excess lifetime cancer risk was calculated using the risk factors of International Commission on Radiological Protection and Biological Effects of Ionizing Radiation. Thus, the values obtained when compared with their corresponding world permissible values, were found to be below the standard limits. _____________________________________________________________________________________________