1. Department of Physics, Faculty of Science, University of Lagos, Akoka, Lagos, Nigeria
2. Department of Radiation Biology, Radiotherapy, Radiodiagnosis and Radiography, College of Medicine, Lagos University Teaching Hospital, Idi-Araba, Lagos, Nigeria
3. Environmental Radioactivity Laboratory, iThemba Labs, Somerset West, South Africa
4. Department of Physics, University of Ibadan, Ibadan, Oyo State, Nigeria