1. Department of Occupational and Environmental Medicine International St. Mary’s Hospital Catholic Kwandong University Incheon Korea
2. Department of Statistics Dongguk University Seoul Korea
3. Occupational Safety and Health Research Institute Korea Occupational Safety and Health Agency Ulsan Korea
4. Department of Occupational and Environmental Medicine Inha University Incheon Korea
5. Department of Occupational and Environmental Medicine College of Medicine Hanyang University Seoul Korea
6. Department of Preventive Medicine College of Medicine The Catholic University of Korea Seoul Korea
7. Department of Environmental Health Korea National Open University Seoul Korea