*Corresponding author e-mail: prof.lai2014@gmail.com © 2016 NSP Natural Sciences Publishing Cor. J. Rad. Nucl. Appl. 1, No. 1, 25-30 (2016) 25 Journal of Radiation and Nuclear Applications An International Journal http://dx.doi.org/10.18576/jrna/010104 Measurement of Radioactivity in Soil Samples for Selected Regions in Thi-Qar Governorate-Iraq Laith Ahmed Najam 1,* , Hazim Louis Mansour 2 , Nada Fathil Tawfiq 3 and Mahmood Salim Karim 2 1 Department of Physics, College of Science, University of Mosul, Mosul, Iraq. 2 Department of Physics, College of Education, Al-Mustansiriyah University, Iraq. 3 Department of Physics, College of Science, Al-Nahrain University, Iraq. Received: 21 Apr. 2016, Revised: 22 Jun. 2016, Accepted: 24 Jun. 2016. Published online: 1 Sep. 2016. Abstract: In the present work, we have been specific activity concentrations in five soil samples for selected regions in Thi-Qar governorate by using high purity germanium (HPGe) detector. The results indicated that, the specific activity, for 238 U was ranged from (33.67±5.8 Bq/kg) in AL-refai region to (23.92±4.8 Bq/kg) in Suq-AL- shuyukh region, for 232 Th was ranged from (27.56±5.2 Bq/kg) in AL- refai region to (18.27±4.2 Bq/kg) in Suq-AL- shuyukh region, for 40 K was ranged from (376.32±19.3 Bq/kg) in AL- refai region to (236.84±15.3 Bq/kg) in Suq-AL- shuyukh region, and for 137 Cs was ranged from (4.2±2.0 Bq/kg) in AL-refai region to (B.D.L) in (Suq-AL-shuyukh),[AL-nasiriyah (Sayed dakhil)] and (AL- hmmar) regions, respectively, with an average values of (29.2±5.1 Bq/kg) , (22.7±4.1 Bq/kg), (304.6±69.1 Bq/kg) and (3.15±1.05 Bq/kg), for 238 U, 232 Th, 40 K and 137 Cs, respectively. In order to asses the radiological hazards of the radioactivity in soil, radium equivalent activity, absorbed gamma dose rate, indoor and outdoor annual effective dose equivalent, external annual effective dose, activity concentration index and both (external and internal) hazard indicies have been determined, and were found to be less than the allowed values given by (UNSCEAR reports). Keywords: (HPGe) detector, soil, specific activity, radionuclides, hazards indicies, Thi-Qar governorate. 1 Introduction Radionuclides have been present always in every environment of the earth’s surface. Only nuclides with half-lives comparable to the age of the earth or their corresponding decay products, existing in terrestrial materials, can still be found today on earth, e.g. 40 K, and the radionuclides from the Uranium and Thorium series [1], Gamma radiation emitted from naturally occurring radioisotopes, such as K-40 and the radionuclides from the Th-232 and U-238 series and their decay products (also called terrestrial background radiation), which exist as trace levels in all ground formations, represents the main external source of irradiation to the human body [2,3]. External exposure to radiation arises from natural and man-made radioactivity. Natural background radiation exposure is mainly caused by primordial radioactivity and cosmic radiation. Primordial radioactivity is mainly due to the presence of Uranium and Thorium series radionuclides and 40 K in the earth’s crust. Cosmic radiation comes through the earth’s atmosphere, from the sun and galaxies. The primary cosmic radiation interacts with the atmospheric matter and produces cosmogenic radionuclides also known as secondary cosmic radiation [4-6]. Thi-Qar governorate situated in the south east of Iraq, and it is lies in the heart of Iraqi’s marshland areas. It is bordered by Wassit governorate to the north, Al-Qadissiya governorate to the northwest, Al-Muthanna governorate to the west, Basrah governorate to the south, and Missan governorate to the northeast . Its largest city is Al- Nasiriyah, with location of latitude (30.33º-32.20º N), and longitude (45.37º -47.12º E). It is located about (4-9 m) above the sea level, with a total area of about (12900 km 2 ) [7]. The aim of the present work is to determine the specific activity concentrations of ( 238 U, 232 Th, 40 K and 137 Cs), and the associated radiation hazards such as radium equivalent activity, absorbed gamma dose rate, indoor and outdoor annual effective dose equivalents, external annual effective dose, activity concentration index, internal and external hazard indicies in surface soil samples for some selected regions in Thi-Qar governorate by using high