Natural radioactivity concentrations in soil samples along the Amman Aqaba highway, Jordan

The specific activity and the gamma-absorbed dose rates of the terrestrial naturally occurring radionuclides (U-238, Th-232, and K-40) were determined in roadside soil cores obtained from eight sites along Amman Aqaba National Highway (AANH), using HPGe gamma-ray spectrometry. The soil activity ranged from 22 to 104 Bq kg(-1) for U-238, 21 to 103 Bq kg(-1) for Th-232, and 138 to 601 Bq kg(-1) for K-40. The highest mean value of U-238 was found in the core samples obtained from a site close to Al-Hassa phosphate mine. The study yielded an annual effective dose equivalent in the range of 40-151 muSv. The average value falls within the global range of outdoor radiation exposure given in UNSCEAR-2000 publications. (C) 2003 Elsevier Ltd. All rights reserved.