1. Department of Epidemiology and Health Statistics, School of Public Health, Ningxia Medical University, Yinchuan, China
2. Ningxia Center for Disease Control and Prevention, Yinchuan, China
3. Key Laboratory of Environmental Factors and Chronic Disease Control, Ningxia Medical University, Yinchuan, Ningxia China
4. Department of Community Nursing, School of Nursing, Ningxia Medical University, Yinchuan, Ningxia, China
5. Department of Occupational and Environmental Hygiene, School of Public Health, Ningxia Medical University, Yinchuan, Ningxia, China
6. Department of Nutrition and Food Hygiene, School of Public Health, Ningxia Medical University, Yinchuan, Ningxia, China