What Does Vaping Do to Your Lungs? Johns Hopkins Medicine What are the best mouth to lung (MTL) vape devices? The Truth About What Vaping Is Doing to Your Body American Lung Association Mouth to Lung Vaping: Why It's Coming Back New lung scans prove vaping is toxic. The science is officially in. Scans show that teens have developed "popcorn lung" as a result of vaping. It's a permanent, chronic disease that shortens