Ethics approval and consent to participate
This study was performed in accordance with the Declaration of Helsinki. This human study was approved by the University of British Columbia research ethics board - approval: H11-01831. The study’s clinical trial registration number is NCT02017431 - registered with ClinicalTrials.gov. Participant registration took place from Jan-2014 to Apr-2017. All adult participants provided written informed consent to participate in this study. Data were collected at the Vancouver General Hospital and Air Pollution Exposure Laboratory, University of British Columbia, Vancouver, BC, Canada.