1. National Cancer Control Institute, National Cancer Center, Goyang-si, Gyeonggi-do, South Korea
2. The Institute for Occupational Health, Yonsei University College of Medicine, South Korea
3. Graduate School of Public Health, Yonsei University, Seoul, South Korea
4. Department of Preventive Medicine, College of Medicine, Yonsei University, Seoul, South Korea
5. Inchen Worker's Health Center, Incheon, South Korea