M.R. Abdi - Department of Physics, Azad University of Shahreza, Isfahan ۸۶۱۴۵-۳۱۱, Iran
H. Faghihian - Department of Physics and Chemistry, University of Isfahan, Isfahan Iran
M. Kamali - Central Laboratory, University of Isfahan, Isfaha

A reconnaissance study has been made on the distribution of 238U, 232Th, 40K, 137Cs and geochemical features in soils and sediments samples at various locations in the coast of Persian Gulf. In this study gamma-ray spectrometer based on hyper-pure germanium detector and a PC based MCA and X-ray fluorescence (XRF) method were used. Estimation of the measured radionuclide content has been made for the absorbed dose rate of gamma radiation. The Activity concentration (A), the equivalent radium (Req) and the external hazard index (Hex) which resulted from the natural radionuclide in soil and sediments are also calculated. The base-line data of radio nuclides and heavy metals in view of the commissioning of nuclear and nonnuclear industries for the coast of Bushehr, which does not exist yet was obtained. Activity concentration levels due to radio nuclides were measured in 50 soil and sediment samples collected from this region. The measurement was performed with respect to their gamma radioactivity for a counting time of 24 hours interval.From the measured spectra, activity concentrations were determined for 40K (range from 108 to 520 Bq Kg-1), 137Cs (From 6 to 40 Bq Kg-1), 238U (from 12 to 75 Bq Kg-1) and 232Th (from 8 to 33 Bq Kg-1) with lowest limit detection (LLD) of respectively 68, 3.2, 4.3 and 4.3 Bq Kg-1. The dose rate from ambient air at the soil ranges was between 14 to 44 nGy h-1 with an average of 30.56 ± 7.86 nGy h-1.

Natural radionuclide, Gamma spectroscopy, Uranium, Thorium, Cesium, Potassium, HPGe, Soil, Bushehr, Persian Gulf