1. School of Medicine, Tehran University of Medical Science-International Campus (TUMS-IC), Tehran, Iran
2. Occupational Diseases Research Center, Tehran University of Medical Sciences, Tehran, Iran
3. Institute for Occupational, Social and Environmental Medicine, University Hospital RWTH Aachen University, Aachen, Nordrhein-Westfalen, Germany
4. Community and Preventive Medicine Department, Tehran University of Medical Sciences, Tehran, Iran