1. Department of Occupational and Environmental Health, School of Public Health, Xi’an Jiaotong University Health Science Center, Xi’an 710061, China
2. Key Laboratory for Disease Prevention and Control and Health Promotion of Shaanxi Province, Xi’an 710061, China
3. Key Laboratory of Trace Elements and Endemic Diseases in Ministry of Health, Xi’an 710061, China
4. Key Laboratory of Environment and Genes Related to Diseases, Xi’an Jiaotong University, Ministry of Education, Xi’an 710061, China
5. Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, Beijing 100191, China
6. Research Institute of Public Health, School of Medicine, Nankai University, Tianjin 300071, China
7. School of Nursing, Peking University, Beijing 100191, China