1. Key Laboratory of Chemical Safety and Health
2. National Institute for Occupational Health and Poison Control
3. Chinese Center for Disease Control and Prevention
4. Beijing
5. China
6. School and Hospital of Stomatology
7. Peking University
8. Luoyang Center for Disease Control and Prevention
9. Luoyang
10. Henan Provincial Institute for Occupational Health
11. Zhengzhou