1. Department of Emergency Medicine, Hallym University Dongtan Sacred Heart Hospital, Hwaseong, Korea.
2. Department of Epidemiology, School of Public Health, Seoul National University, Seoul, Korea.
3. Department of Emergency Medicine, University of California Irvine School of Medicine, Irvine, CA, USA.
4. Department of Environmental Medicine, Ewha Womans University College of Medicine, Seoul, Korea.
5. Department of Preventive Medicine, College of Medicine, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul, Korea.