Although previous studies have demonstrated that particulate matter exposure activated the ROS/TGF-β1/Smad3 signaling pathway to induce myocardial fibrosis (21), our study explained that PM2.5 exposure not only increased cardiomyocyte and fibrosis levels by TGF-β, but also promotes this outcome through macrophage–sEV secretions. This evidence concerns the gene TGFB1 and Myocardial fibrosis.