Explainer: What are e cigarettes? 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 All E Cigarettes Emit Harmful Chemicals, but Some Emit More Than Others Berkeley Lab Berkeley Lab News Center FDA chief threatens to take e cigarettes off the market E Cigarettes and Vape Devices NH Department of Environmental Services