1. Department of Preventive Medicine, College of Medicine, Chungbuk National University, Cheongju, Korea.
2. Department of Internal Medicine, Division of Endocrinology and Metabolism, School of Medicine, Konyang University, Daejeon, Korea.
3. Environmental Health Research Division, Environmental Health Research Department, National Institute of Environmental Research, Incheon, Korea.
4. Department of Preventive Medicine, Chung-Ang University College of Medicine, Seoul, Korea.