1. Department of Preventive Medicine, School of Public Health, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
2. Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway
3. Centre for International Health, Department of Global Public Health and Primary Care, Faculty of Medicine, University of Bergen, Bergen, Norway
4. Department of Public Health, Environment, Occupation and Health, Danish Ramazzini Centre, Aarhus University, Aarhus, Denmark
5. The National Research Centre for the Working Environment, Copenhagen, Denmark