1. Department of Occupational and Environmental Medicine, Gyeongsang National University Changwon Hospital, Gyeongsang National University School of Medicine, Changwon, Korea.
2. Environmental Health Center, University of Ulsan College of Medicine, Ulsan, Korea.
3. Department of Occupational and Environmental Medicine, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea.
4. Department of Occupational and Environmental Medicine, Soonchunhyang University Cheonan Hospital, Soonchunhyang University College of Medicine, Cheonan, Korea.
5. Environmental Health Research Division, National Institute of Environmental Research, Incheon, Korea.