1. Department of Community, Environmental and Occupational Health, Ain Shams University, Cairo, Egypt
2. Department of Public Health, Cairo University, Cairo, Egypt; and International Union Against Tuberculosis and Lung Disease, Union Middle East, Cairo, Egypt
3. Department of Oncology, Lombardi Cancer Center, Georgetown University, Washington DC, USA
4. Department of Epidemiology and Preventive Medicine, School of Medicine, University of Maryland, Baltimore, Maryland, USA
5. Department of Community, Environmental and Occupational Health, Ain Shams University, Cairo, Egypt; deceased