1 Department of Epidemiology, School of Public Health, Shanxi Medical University, Taiyuan 030001, Shanxi, China;Department of Epidemiology, School of Public Health, Shanxi Key Laboratory of Environmental Health Impairment and Prevention, NHC Key Laboratory of Pneumoconiosis, MOE Key Laboratory of Coal Environmental Pathogenicity and Prevention, Shanxi Medical University, Taiyuan 030001, Shanxi, China.
2 Department of Epidemiology, School of Public Health, Shanxi Medical University, Taiyuan 030001, Shanxi, China.
3 Department of Epidemiology and Environmental Health, School of Public Health and Health Professions, The State University of New York at Buffalo, Buffalo, NY, USA..