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. Is Vaping Worse Than Smoking? St. Vincent's Medical Center An updated overview of e cigarette impact on human health Respiratory Research Springer Nature Link Frontiers Pulmonary function and physical performance in adolescent e cigarette users: a narrative review PET imaging shows greater lung inflammation in e cigarette users than cigarette smokers