1. Department of Preventive Medicine, Dong-A University School of Medicine, The Research Society of Environmental Genetic Epidemiology, Busan, Korea.
2. Department of Public Health, Kobe University School of Medicine, Japan.
3. Department of Laboratory Medicine, Dong-A University School of Medicine, Busan, Korea.
4. Department of Microbiology, Dong-A University School of Medicine, Busan, Korea.
5. Department of Preventive Medicine, Kosin Medical College, Busan, Korea.
6. Department of Occupational Medicine, Korea University, Seoul, Korea.
7. Department of Health Care Center, Changwon Hospital, Changwon, Korea.