الملخص الإنجليزي
Due to the location of Sultanate of Oman there is an anxious feeling of possible poliution by artificial radionuclides. This study is conducted for the investigation of natural and artificial radionuclides in the surface soil and beach sediments in the most sensible region which is Governorate of Musandam. Governorate of Musandam lies in the extreme north of the Sultanate. Its neighbors Iran in the North and United Arab Emirates in the west and overlooks the Arabian Gulf. It has a strategic waterway (Strait of Hormuz) for oil production transport and international trading. Determination of the natural radionuclides as well as artificial radionuclides was carried out by means of gamma-ray spectroscopy based on a highly pure germanium coaxial detector (HPGe) system, Measurements of the activity concentrations of -U, 232Th, 40K and 137Cs of the collected samples were carried out. The average activities in soil for 238U, 232Th, 40K were found in Bą kg: (in dry weight) to be 13.94 2.4, 4.5+0.3, and 86.4+2.5 Bq kg ?, respectively, whereas in beach sediments the average activities for 238U, 232Th, 40K were 11.24 1.5, 1.240.2 and 53.2+1.6 respectively in Bq kg. The results show that the mean activity of all measured natural radionuclides is lower than the world averages. The presence of Cs in the analyzed surface soil samples were low in most locations with an average of 1.7:0.1 Bq kg- and less than the detection limit in beach sediments. Radiological hazards were assessed through annual effective dose and radium equivalent (Raen). The mean values for the et dose and radium equivalent index were determined as: 12.3 uSy y' and 21.2 Bq kg respectively, they were very low compared with the world average of 70 ușy y for annual effective dose and 128.7 Bq kg for radium equivalent. The safe limit of radium equivalent activity is (370 Bq kg) and the safe limit of effective dose is 1 mSv y, thus all investigated areas are safe and suitable for agriculture, urbanization and tourism.
