Experts warn that flavored e cigarettes can cause irreversible lung damage, as seen in a U.S. teenager who developed "popcorn lung"a severe and permanent condition called bronchiolitis obliteransafter secretly vaping for three years. No Cure for Popcorn Lung: Vapers and Workers Beware! iGlobenews Popcorn Lung: The Deadly Secret in Your Vape! Did you know that the sweet, tempting flavor in your e liquid could be hiding a chemical called Diacetyl? This chemical, which tastes Bronchiolitis obliterans Wikipedia Popcorn Lungs: Teen addicted to vaping diagnosed with popcorn lung: Know what it is and what are the risks The Times of India Uncovering Hidden Risks: Popcorn Lung and Vaping Dangers