Department of Epidemiology and Biostatistics, School of Public Health, Peking University Health Science Center, 38 Xueyuan Road, Beijing, 100191, China. Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA. Chinese Academy of Medical Sciences, Beijing, China. Clinical Trial Service Unit and Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, University of Oxford, Oxford, UK. Department of Biostatistics, School of Public Health, Nanjing Medical University, Nanjing, China. Liuyang Center for Disease Control and Prevention, Liuyang, Hunan, China. China National Center for Food Safety Risk Assessment, Beijing, China. Department of Epidemiology and Biostatistics, School of Public Health, Peking University Health Science Center, 38 Xueyuan Road, Beijing, 100191, China. lvjun@bjmu.edu.cn. Key Laboratory of Molecular Cardiovascular Sciences (Peking University), Ministry of Education, Beijing, China. lvjun@bjmu.edu.cn. Peking University Institute of Environmental Medicine, Beijing, China. lvjun@bjmu.edu.cn. Department of Epidemiology and Biostatistics, School of Public Health, Peking University Health Science Center, 38 Xueyuan Road, Beijing, 100191, China. lmleeph@vip.163.com.