1. Department of Occupational Health and ToxicologySchool of Public Health, Fudan UniversityChina
2. Henan Institute of Occupational HealthChina
3. Department of Occupational HealthSchool of Public Health, Zhengzhou UniversityChina
4. Institute of Occupational MedicineChina
5. Department of Epidemiology and BiostatisticsCollege of Public Health, University of South FloridaUSA
6. School of Public Health, University of Illinois at ChicagoUSA