It's official. Flavored e cigarettes cause permanent lung damage. And doctors are already seeing it happen. In the United States, a teenager developed something called popcorn lung after secretly vaping for three years. What's in an E Cigarette? American Lung Association Banned Dangerous Vape Ingredients to Avoid in Your Vape Juice Popcorn Lung: A Dangerous Risk of Flavored E Cigarettes American Lung Association