1Department of Occupational and Environmental Medicine, Pusan National University, Yangsan Hospital, Yangsan, Korea
2Department of Preventive and Occupational Medicine, Pusan National University, School of Medicine, Yangsan, Gyongnam, Korea
3Occupational Safety & Health Research Institute, Korea Occupational Safety & Health Agency, Ulsan, Korea
4Department of Occupational and Environmental Medicine, Haeundae Paik Hospital, Inje University, Busan, Korea
5Department of Occupational and Environmental Health, Yonsei University Graduate School of Public Health, Seoul, Korea JFIF d d Ducky d qhttp://ns.adobe.com/xap/1.0/