Interstitial lung diseases (ILDs) are serious conditions resulting in lung scarring, breathing difficulties, and a severely shortened lifespan. Air pollution is associated with ILD development and progression, but we do not understand why. This project aims to answer this question by looking at cellular and genetic changes that occur in the lungs of patients with ILD following exposure to air pollution. Using satellite-derived air pollution and clinical data from patients, we will determine if certain genes result in worse clinical outcomes when patients with ILD are exposed to more air pollution. Next, we will examine how air pollution modifies how genes are turned on or off in ILDs, through a process called DNA methylation. Lastly, we will use high-resolution imaging tools to understand how the structure of the lungs change in response to air pollution in patients with ILD. This research will help us to understand how air pollution contributes to progressive lung scarring in patients with ILD and may identify new targets for therapies to reverse lung scarring. This work will inform environmental health policies aimed at protecting vulnerable populations, including patients with ILD and other chronic lung diseases.