In recent years, the number of e cigarette users worldwide has sharply increased, with many believing that vaping is less harmful than smoking traditional cigarettes. However, health experts are warning of its negative Vaping: How popular are e cigarettes? CDC: E cigarettes a growing health concern E Cigarettes and Vape Devices NH Department of Environmental Services How have e cigarettes changed over time? What are e cigarettes and the controversies that surround them? On Medicine