1. The Key Laboratory of Typical Environmental Pollution and Health Hazards of Hunan Province, Department of Epidemiology and Health Statistics, School of Public Health, Hengyang Medical School, University of South China, Hengyang 421001, China
2. Hunan Provincial Key Laboratory of Clinical Epidemiology, Xiangya School of Public Health, Central South University, Changsha 410017, China
3. Changsha Yuhua District Center for Disease Control and Prevention, Changsha 410014, China
4. Changsha Center for Disease Control and Prevention, Changsha 410004, China
5. Hengyang Medical School, The First Affiliated Hospital, University of South China, Hengyang 421001, China