Wildfire smoke contributions to polycyclic aromatic hydrocarbon loadings in urban surface grime

Across the western United States and Canada’s western provinces, summertime air quality is increasingly defined by wildfire smoke. As urban environments present many surfaces (e.g., buildings, roadways) to which pollutants can partition/deposit, my team hypothesized that urban surface grime in wildfire-influenced regions will 'capture' toxic smoke components, thereby prolonging the air quality and health impacts of smoke incursions. In this talk, I will share new results from two sampling campaigns designed to test this hypothesis, in which we quantified polycyclic aromatic hydrocarbons (PAHs) in surface grime collected using a network of low-cost samplers deployed in smoke-influenced and background locations. In particular, I will describe site-specific PAH concentrations and congener profiles; contextualize campaign data using air mass back-trajectory analysis and particulate matter compositional data from co-located stations (where available); and highlight the potential human and ecosystem health impacts of the widespread wildfire smoke contamination of urban surfaces identified here.