Teens say they don't vape, they 'Juul.' That makes the activity hard to track Los Angeles Times E cigarettes linked with blood vessel damage National Institutes of Health (NIH) Johns Hopkins researchers find thousands of unknown chemicals in electronic cigarettes Hub Cigarette lectronique Annecy (74) Blu E cigarettes, heated tobacco and smokeless tobacco products European Lung Foundation How to Quit Vaping When It's Really, Really Hard SELF