1. Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
2. Department of Epidemiology, School of Public Health, Zunyi Medical University, Zunyi 563060, China
3. School of Nursing and Health Studies, Northern Illinois University, DeKalb, Illinois 60115, United States
4. Department of Epidemiology and Biostatistics, College for Public Health & Social Justice, Saint Louis University, St. Louis, Missouri 63104, United States
5. School of Social Work, College for Public Health and Social Justice, Saint Louis University, St. Louis, Missouri 63104, United States