Can vaping cause cancer? The evidence suggests it might. The Washington Post Propylene glycol, a component of electronic cigarette liquid, damages epithelial cells in human small airways Respiratory Research Springer Nature Link Although research on cancer risks associated with vaping is still limited, a 2025 systematic review found substantial evidence that e cigarette exposure is associated with biomarkers reflective of cancer disease risk. This includes Thirdhand Vapor from E cigarettes Damages the Lungs of Mice Thirdhand Smoke Resource Center