PROJECT SUMMARY/ABSTRACT Climate change poses a significant threat to respiratory health in patients with asthma through synergistic disturbances in air quality and airborne allergens. However, the effects of climate change and air pollution are not equal and are substantially greater in socially vulnerable populations of children. For example, Black and Hispanic children are more likely to live in lower opportunity neighborhoods due to systemic structural racism and historic red lining practices, are exposed to more pollutants, and have more severe asthma exacerbations attributable to air pollution. This is a public health crisis since asthma exacerbations are a primary predictor of future hospital admission and significantly increase the risk of asthma-related death. Dr. Fitzpatrick has built an extensive research program focused on socially vulnerable populations of children with asthma. Her current R01, Symptom Clusters in Children with Exacerbation-Prone Asthma (R01NR018666), is a 12-month longitudinal study of school-age children with a recent asthma exacerbation who are clustered into separate groups based on a battery of patient-reported outcome (symptom) measures. Clinical outcomes and inflammatory and metabolic pathways are then compared between cluster groups. However, climate and air quality are not assessed. This administrative supplement will utilize previously collected data and samples from the parent R01 and will add new assessments (characterization of social vulnerability and air quality), new experiments (transcriptomics and multi-omic associations), and additional personnel with expertise to pursue Climate Change and Health (CCH) initiatives. The central hypothesis is that climate change-induced disruptions in air quality worsen asthma inflammation, symptoms, and longitudinal outcomes in school-age children with asthma and that these effects are mediated by social vulnerability. Specific aims are to: 1) determine associations between climate, air quality, symptoms, and outcomes in children with exacerbation- prone asthma during two climate seasons, and 2) determine the biological impact of climate and pollutants in children with exacerbation prone asthma. This administrative supplement addresses two Core Pillars of the CCH Initiative: Health Effects Research, investigation of the influences of climate change on health outcomes and biological mechanisms, and Health Equity, recognizing and responding to the needs of populations most at risk. The timeline for completion is one year. The results are expected to advance systems-level understanding of the impact of climate change-associated air pollution on vulnerable children with asthma and provide key preliminary data for an R01 interventional study in this field.