Project Summary Climate change is fueling dramatic increases in the frequency, duration, and intensity of wildfires in the Western USA and globally. The contribution of wildfire smoke to air quality is no longer transient or negligible as recent studies demonstrated that wildfire smoke has either stagnated or reversed previous multi-decadal progress in reducing fine particulate matter (PM2.5) concentrations in three-quarters of states in the contiguous USA (CONUS). Moreover, since 2016, wildfire smoke has added an average of 1 µg/m3 to annual ambient PM2.5 concentrations in the eight most affected states in the West and Midwest. Wildfires release large amounts of particles, toxicants, and carcinogens into the atmosphere, which can impact the health of populations both near and far from the burning sites. Studies, including our own, have documented that wildfire smoke worsens mental health and exacerbates cardio-pulmonary diseases within days of exposure, and may cause lung injury and obstructive airway changes within weeks to months of exposure. However, the impact of repetitive wildfire smoke exposure on chronic health consequences remains unknown. Specifically, despite cancer relevance of wildfire smoke and the growing population of cancer survivors, the risk for developing and surviving cancer under repetitive insults from wildfire smoke is a significant knowledge gap. Understanding this risk is an interdisciplinary research priority for both cancer and climate researchers. Whereas the lack of a reliable assessment of wildfire smoke exposure has traditionally impeded scientific progress, the newest advancements in air quality modeling have the potential to advance the field. This includes the daily wildfire-driven PM2.5 concentration estimates at 10 × 10 km resolution that is available for the entire CONUS from 2006 to 2022. Therefore, we proposed to link the wildfire smoke data to cancer incidence and somatic mutation data to examine whether wildfire smoke affects the risk for developing cancers (Aim 1). Aim 2 will link wildfire smoke data to cancer mortality and survival data to assess whether wildfire smoke affects the risk for surviving cancers. With the projected increase in wildfires, delineating these relationships has the potential to inform new public health and climate policies to better protect vulnerable populations from contracting cancer and to improve health outcomes in cancer survivors following wildfire smoke exposures. Finally, we will work with the Community Engagement Core to foster increased individual- and community- level decision-making and climate health literacy by translating our team’s research results to identified audiences using culturally-centered, science-communication approaches.