1. Department of Environmental and Occupational Health, School of Public Health, Guangdong Medical University, Dongguan 523808, P. R. China
2. Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan 523808, P. R. China
3. Department of Occupational Health and Occupational Medicine, School of Public Health, Southern Medical University, Guangzhou 510515, Guangdong, P. R. China
4. Department of Emergency Intensive Care Unit, Affiliated Dongguan People’s Hospital, Southern Medical University, Dongguan 523808, Guangdong, P. R. China