Study of natural radioactivity to Assess of radiation hazards from soil samples collected from Mounana in south-east of Gabon

Background: the present work aims to determine the activity concentrations of^226ra, ^233th and ^40k in soil samples collected in mounana in the southeasternregion of gabon, to evaluate the contribution of the natural. materials andmethods: an hpge p-type detector coupled with a multichannel analyzer dsa-1000 was used to perform measurements and process data. data acquisition andanalysis were made possible using genie 2000 software version 2.1 and detectorwas calibrated using the iaea certified soil reference standard material multigamma(no71863/3). results: the activity concentrations of ^226ra, ^232th and ^40kvaried respectively from 12 ± 03 bq kg-1 to 23022 ± 2572 bq kg^-1, 12 ± 04 bq kg-1 to 265 ± bq kg^-1 and64 ± 13 bq kg-1 to 811 ± 74 bq kg-1with means values of2811 ± 198bq kg^-1, 63 ± 14 bq kg^-1 and of 355 ± 93 bq kg^-1wet weight. in orderto assess the radiological risks due to primordial radionuclides in mounana,the absorbed dose rate, effective dose, radium equivalent and externalhazard index were estimated. conclusion: absorbed dose rates which havebeen calculated for each site varied from 26.12 ngy h^-1 to 10817.99ngy h^-1with a mean value of 1352.76 ngy h^-1. the mean value of annual effectivedose was estimated to be 10.96 msv y^-1 from the studied area. the areasinvestigated in this study showed a strong radioactive contamination of sitesinhabited by populations.