1. Department of Occupational and Environmental Health, School of Public Health, Yangzhou University, Yangzhou 225009, China
2. Department of Radiology and Functional Examination, Nanjing Prevention and Treatment Center for Occupational Diseases, Nanjing 210018, China
3. Lanzhou 7th Rest Center for Retired Cadre, Gansu Military Region, Lanzhou 730000, China