In Battle With Juul, San Francisco Becomes First City To Ban E Cigarettes Half of all e cigarettes in the EU come from illegal sources Similar DNA changes found in cells of both smokers and e cigarette users UCL News UCL University College London E cigarettes, invented in China in 2003 as a smoking alternative, are safer than combustible cigarettes but not risk free, exposing users to nicotine and other chemicals that can harm the heart, lungs, and