1. Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University , Dongguan 523808, P.R. China
2. Department of Preventive Medicine, School of Public Health, Guangdong Medical University , Dongguan 523808, P.R. China
3. Department of Hospital Infection Management, Dongguan Maternal and Child Health Care Hospital , Dongguan 523120, P.R. China
4. Foshan Institute of Occupational Disease Prevention and Control , Foshan 528000, P.R. China
5. Health Education and Promotion Department, Shenzhen Luohu Hospital Group , 518001, P.R. China