1Department of Preventive Medicine and Public Health, College of Medicine, Kwandong University, Institute for Occupational and Environmental Health, Kwandong University, Korea.
2Department of Preventive Medicine, College of Medicine, Yonsei University, Institute of Health Promotion, Graduate School of Public Health, Yonsei University, Korea. ohrr@yuhs.ac JFIF d d Ducky d qhttp://ns.adobe.com/xap/1.0/