New study comes the closest yet to proving that e cigarettes aren't as dangerous as smoking Thirdhand Vapor from E cigarettes Damages the Lungs of Mice Thirdhand Smoke Resource Center Cytotoxic and oxidative effects of commercially available propylene glycol (PG) and vegetable glycerin (VG): Common humectants in electronic cigarettes ScienceDirect Electronic cigarette aerosols alter the expression of cisplatin transporters and increase drug resistance in oral cancer cells Scientific Reports