1. Department of Epidemiology and Biostatistics College of Public Health Zhengzhou University Zhengzhou PR China
2. Guangdong Provincial Engineering Technology Research Center of Environmental and Health Risk Assessment Department of Occupational and Environmental Health School of Public Health Sun Yat‐sen University Guangzhou PR China
3. Department of Epidemiology and Preventive Medicine School of Public Health and Preventive Medicine Monash University Melbourne Australia