1. Health and Environment Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
2. Department of Statistics and Epidemiology, Faculty of Health, Tabriz University of Medical Sciences, Tabriz, Iran
3. Department of Environmental Health Engineering, Faculty of Health, Tabriz University of Medical Sciences, Tabriz, Iran
4. Department of Occupational Health Engineering, Faculty of Health, Tabriz University of Medical Sciences, Tabriz, Iran
5. Department of Medicine, Faculty of Medicine, University of Toronto, Toronto, ON M5G 2C4, Canada