1. Department of Safety Engineering, University of Wuppertal,
Wuppertal, Germany, lijian1974@hotmail.com, School of Public Health, Fudan University, Shanghai,
China, School of Public Health, Kunming Medical University,
Kunming, China
2. School of Public Health, Fudan University, Shanghai,
China
3. School of Nursing, Fudan University, Shanghai, China
4. School of Public Health, Kunming Medical University,
Kunming, China
5. School of Nursing, Kunming Medical University, Kunming,
China
6. and Task-Consult, Denmark
7. Department of Safety Engineering, University of Wuppertal,
Wuppertal, Germany