1 Department of Occupational and Environmental Health, Guangdong Provincial Engineering Technology Research Center of Environmental Pollution and Health Risk Assessment, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China.
2 School of Public Policy and Management, Tsinghua University, Beijing 100084, China; High-Tech Research and Development Center, Ministry of Science and Technology, Beijing 100044, China.
3 Department of Occupational and Environmental Health, Guangdong Provincial Engineering Technology Research Center of Environmental Pollution and Health Risk Assessment, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China. Electronic address: donggh5@mail.sysu.edu.cn.