GK is supported by an MRC Skills Development Fellowship [MR/T025352/1]. MB and TP are supported by a National Institutes of Health, grant number [R01HD092580-01A1]. JB and ME are supported by the Pathways to Equitable Healthy Cities grant from the Wellcome Trust [209376/Z/17/Z] and by a grant from the US Environmental Protection Agency (EPA), as part of the Centre for Clean Air Climate Solution (assistance agreement no. R835873). This article has not been formally reviewed by the EPA. The views expressed in this document are solely those of the authors and do not necessarily reflect those of the EPA. The EPA does not endorse any products or commercial services mentioned in this publication. Infrastructure support for this research was provided by the National Institute for Health Research Imperial Biomedical Research Centre (BRC). This work was part supported by the MRC Centre for Environment and Health, which is currently funded by the Medical Research Council (MR/S019669/1, 2019-2024).