Natural radioactivity could be found in various degrees in all media in the environment (water, soils, vegetation, food), and depending on the activity and concentration of radionuclides dealt with, the principal concern is the consequence of exposure to low doses and low dose rates. In this work, we present a study on the measurements of natural
radioactivity levels and the external exposure rates in 10 soil samples collected from the city of Ouagadougou in Burkina Faso, using a high-resolution gamma-ray spectrometry with HPGe detector. The specific activity concentrations of the identified radionuclides 238U, 232Th, 40K and 137Cs range respectively from 23.14 ± 1.28 Bq/kg to 52.07 ± 2.59 Bq/kg, 14.83 ± 1.26 Bq/kg to 47.87 ± 3.59 Bq/kg, 114.37 ± 6.83 Bq/kg to 370.93 ± 18.12
Bq/kg and 0.33±0.17 Bq/kg to 7.09±0.39 Bq/kg. From the primordial radionuclides 238U, 232Th and 40K activity concentrations in the soil samples, the absorbed gamma dose rates and the annual effective doses in air were calculated to assess public terrestrial radiation exposures. The absorbed dose rates varied from 27,17 ± 1,71 nGy/h to 55,01 ± 6,937 nGy/h while the annual effective doses ranged from 33.32 ± 2.10 μSv to 67.46 ± 08.50 μSv. The
measured values for the terrestrial radioactivity are lower than the worldwide averages given by UNSCEAR (2000).

Radionuclide, Natural radioactivity, soil sample, activity concentration