1. Dosimetry and Radiation Protection Laboratory, Centre for Atomic Molecular Physics and Quantum Optics (CEPAMOQ), University of Douala, Douala, Cameroon
2. National Radiation Protection Agency, Yaounde, Cameroon
3. Radiation Protection Institute, Atomic Energy Commission, Legon-Accra, Ghana
4. Department of Physics, Faculty of Sciences, University of Douala, Douala, Cameroon
5. Research Centre for Nuclear Science and Technology, Institute of Geological and Mining Research (IRGM), Yaoundé, Cameroon