World Health Organization (WHO) - Section of Environment and Radiation, World Health Organization (WHO) - Section of Environment and Radiation, World Health Organization (WHO) - Section of Environment and Radiation, Windhoek Central Hospital, Makerere University, Abia State University, Federal Medical Centre, University of North Carolina (UNC) at Chapel Hill - UNC Zambia, University of North Carolina (UNC) at Chapel Hill - UNC Zambia, Chris Hani Baragwanath Academic Hospital, Chris Hani Baragwanath Academic Hospital, Imperial College London - Department of Primary Care and Public Health, London School of Hygiene & Tropical Medicine - Department of Non-Communicable Diseases Epidemiology, World Health Organization (WHO) - Section of Environment and Radiation, World Health Organization (WHO) - International Agency for Research on Cancer (IARC), Fred Hutchinson Cancer Research Center, World Health Organization (WHO) - International Agency for Research on Cancer (IARC) and London School of Hygiene & Tropical Medicine - Department of Non-Communicable Diseases Epidemiology