Health experts warn that flavored e cigarettes may lead to permanent lung damage. A U.S. teenager was diagnosed with "popcorn lung" after covertly vaping for three years, resulting in a lifelong, debilitating condition. E Cigarette Vapor Linked to Lung Cancer in Mice Respiratory Therapy Why Are E Cigarettes Safer Than Cigarettes Vape Blog Compromised blood vessel function caused by cigarettes and e cigarettes is mediated by lung irritation Stanton Glantz blog