1. Guangdong Province Hospital for Occupational Disease Prevention and Treatment, Guangdong Provincial Key Laboratory of Occupational Disease Prevention and Treatment, Guangzhou, Guangdong 510230, China
2. Department of Public Health, Guangzhou Medical University, Guangzhou, Guangdong 510000, China
3. The Centers for Disease Control and Prevention of Haizhu District, Guangzhou, Guangdong 510230, China
4. Department of Public Health, Shanxi Medical University, Tai Yuan, Shanxi 030000, China
5. Department of Public Health, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510230, China