1. Department of Occupational Health EngineeringSchool of Public Health, Tehran University of Medical SciencesIran
2. Department of Epidemiology and BiostatisticsSchool of Public Health, Tehran University of Medical SciencesIran
3. Iranian Petroleum Industry Health Research Institute (IPIHRI), Iran, Occupational and Environmental Health Center (OEHC)Iran
4. Department of HSEQIranian Gas Engineering and Development Company (IGEDC)Iran
5. Department of Occupational Health, Faculty of HealthKashan University of Medical SciencesIran
6. Department of Occupational Health, Faculty of HealthSabzevar University of Medical SciencesIran