Abstract
The activity concentration of natural radioactivity for soil samples collected from western and mid Libyan regions were measured using HPGe detector. The average activity concentration of 226Ra, 232Th and 40K for ten samples were found to be 51.86±7.14, 75.56±10.95 and 128.98±6.88 Bq/kg respectively. 235U was Odetected for six samples with average activity 8.6±1.0 Bq/kg. The results obtained for the corresponding nuclides 226Ra and 232Th are above worldwide average values (35 and 30 Bq/kg) while 40K was smaller than worldwide average (400 Bq/kg). The average outdoor absorbed dose and the annual effective dose rates due to 226Ra, 232Th and 40K were observed to be 21.51±2.93 nGy/h and 0.297±.03 mSv/y respectively, which are lower than world average values (60nGy/h and 0.8 mSv/y). The radium equivalent activity and external hazard indices were found less than the world wide average values.