1. Epidemiology Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, USA
2. Department of Health Statistics, Faculty of Health Services, Second Military Medical University, Shanghai, China
3. Department of Preventive Medicine and Public Health, Creighton University School of Medicine, Omaha, Nebraska, USA
4. Children’s Hospital of Philadelphia and University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
5. Department of Environmental Health, Division of Epidemiology and Biostatistics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
6. Inorganic and Radiation Analytical Toxicology Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA