1. Department of Occupational and Environmental Health School of Public Health Sun Yat‐sen University Guangzhou China
2. Melbourne School of Population & Global Health Allergy and Lung Health Unit Centre for Epidemiology and Biostatistics The University of Melbourne Melbourne Victoria Australia
3. Department of Epidemiology and Preventive Medicine School of Public Health and Preventive Medicine Monash University Melbourne Victoria Australia
4. Department of Basic Sciences Faculty of Allied Health Sciences University of Peradeniya Peradeniya Sri Lanka
5. National Institute of Fundamental Studies Kandy Sri Lanka
6. Maternal and Child Hospital of Maoming City Maoming China