1. State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University , Nanjing 210023 , China
2. School of Earth and Environmental Sciences, Cardiff University , Cardiff CF24 4AT , UK
3. Vanke School of Public Health, Tsinghua University , Beijing 100084 , China
4. Department of Building Science, School of Architecture, Tsinghua University , Beijing 10084 , China
5. Center for Healthy Aging and Development Studies, Raissun Institute for Advanced Studies, National School of Development, Peking University , Beijing 100871 , China
6. Center for the Study of Aging and Human Development and Geriatrics Division, Medical School of Duke University , Durham, NC 27708 , USA