1. Department of Occupational and Environmental Medicine, Inha University, Incheon, Korea
2. Division of Toxicology and Environmental Medicine and
3. Division of Health Studies, Agency for Toxic Substances and Disease Registry, Atlanta, Georgia, USA
4. Division of Environmental Hazards and Health Effects Biometry Activity, National Center for Environmental Health and
5. Office of Science, Office of the Director, National Immunization Program, Centers for Disease Control and Prevention, Atlanta, Georgia, USA