1. Department of Occupational Health and Occupational Diseases, College of Public Health Zhengzhou University Zhengzhou China
2. The Key Laboratory of Nanomedicine and Health Inspection of Zhengzhou Zhengzhou China
3. Safety Management Department of Anyang Iron and Steel Group Company Anyang China
4. Department of Epidemiology and Biostatistics, College of Public Health Zhengzhou University Zhengzhou China