1. Department of Public Health, Esfarayen Faculty of Medical Sciences, Esfarayen, Iran
2. Department of Public Health, School of Health, North Khorasan University of Medical Sciences, Bojnurd, Iran
3. Department of Environmental Health Engineering, School of Health, North Khorasan University of Medical Sciences, Bojnurd, Iran
4. Department of Environmental Health Engineering, School of Public Health and Safety, Shahid Beheshti University of Medical Sciences, Tehran, Iran