Vaping propylene glycol and vegetable glycerine may lead to lung inflammation Vaping may look harmless, but one teenager's diagnosis shows how dangerous it can become. A 17 year old in the U.S. was reportedly diagnosed with bronchiolitis obliterans, better known as popcorn lung, after secretly Vapers 1.3x More Likely to Develop Lung Disease Chattanooga, TN Does Vaping Cause Lung Cancer? What We Know (and Still Don't)