Determination of 226Ra, 232Th, 40K and 235U in soil samples from bauxite core deposits in western Cameroon

• Published in: Radioprotection Vol. 51; no. 3; pp. 199 - 205
• Main Authors: Nguelem, E.J.M., Ndontchueng, M. M., Motapon, O., Darko, E. O., Simo, A.
• Format: Journal Article
• Language: English
• Published: EDP Sciences 01.07.2016
• Subjects: bauxite; BEGe6530 detector; public external radiation dose; radioactivity; soil
• ISSN: 0033-8451; 1769-700X
• DOI: 10.1051/radiopro/2016029

The activity concentrations of 226Ra, 232Th, 40K and 235U in soil samples from a bauxite ore deposit site in Western Cameroon were determined by gamma spectrometry using a Broad-Energy Germanium (BEGe6350) detector. The average activity concentrations of 226Ra, 232Th, 40K and 235U were found to be 124.8 ± 58.1, 157.3 ± 67.3, 670.9 ± 272.3 and 5.8 ± 2.7 Bq kg-1, respectively. The measured activity concentrations of 226Ra, 232Th and 40K were compared with available data in some countries and the world average activity concentration of soil. The radiological hazard indices of radioactivity were calculated, with average values of 416.90 Bq kg-1 for the radium equivalent activity, 188.20 nGy h-1 for the gamma radiation dose rate, 0.23 mSv y-1 for the external outdoor annual effective dose, 0.92 mSv y-1 for the indoor annual effective dose, 1.02 mSv y-1 for the total annual effective dose and 1.13 for the external hazard index, respectively. These radiological hazard index values were also compared with the internationally approved values. Consequently, use of concrete bricks made of soil as building materials might lead to an increased radiation risk for the population of Fongo-Tongo.