1. Department of Occupational and Environmental Health; School of Public Health; Zhengzhou University; 100 Science Avenue Zhengzhou 450001 China
2. School of Public Health; Xinxiang Medical University; 601 Jinsui Avenue Xinxiang 453003 China
3. Center for Reproductive Medicine; Shandong Provincial Hospital Affiliated to Shandong University; 157 Jingliu Road Jinan 250001 China
4. Department of Occupational Disease; Henan Provincial Institute of Occupational Health; Middle Street of Kangfu Zhengzhou 450052 China
5. School of Basic Medicine; Zhengzhou University; 100 Science Avenue Zhengzhou 450001 China