1. Department of Preventive Medicine; Chungnam National University School of Medicine; Daejeon Korea
2. Department of Dermatology; Seoul National University Hospital; Seoul Korea
3. Public Health Medical Service; Boramae Medical Center; Seoul National University College of Medicine; Seoul Korea
4. Department of Health Policy and Management; Seoul National University College of Medicine; Seoul Korea
5. Institute of Human-Environment Interface Biology; Seoul National University; Seoul Korea