Assessment of radioactivity levels in some oil samples from the western desert, Egypt

Distributions of natural gamma-emitting radionuclides were determined in 93 oil samples collected from some petroleum fields in the western desert of Egypt. The radioisotope activities in the area under investigation lay in the range of (21 +/- 4) to (38 +/- 13) Bq circle L-1 for Ra-226, (9 +/- 2) to (15 +/- 5) Bq circle L-1 for Th-232, and (154 +/- 28) to (303 +/- 54) Bq circle L-1;l for K-40. The mean values were 27, 12, and 201 Bq circle L-1 respectively. Among oils, variations in radionuclide activities could be on account of differences in TDS, HCO3, and Ba, with high or low pH. In this environment, oil properties differently affected the mobilization of natural radionuclides. The range of Ra-226 variation had been compared with available data from other countries. The calculated absorbed dose rate ranged from 22.33 to 32.66 nGy circle h(-1) in location (13) and (E) respectively, which was less than the accepted value.