This paper investigates the association between air pollution exposure, and early markers of carotid atherosclerosis within the Canadian Alliance for Healthy Hearts and Minds Cohort Study. Utilizing MRI to measure carotid vessel volume (CWV), the findings showed no direct association for PM₂.₅, but higher NO₂ was linked to reduced CWV and elevated O₃ to increased CWV. These findings suggest a complex relationship between air pollution and cardiovascular health warranting further research, to uncover underlying mechanisms.