Frontiers The Evolving E cigarette: Comparative Chemical Analyses of E cigarette Vapor and Cigarette Smoke Common e cigarette chemical flavorings may impair lung function Harvard T.H. Chan School of Public Health It may look trendy, but vaping is silently damaging your lungs. Behind the flavored puffs lie chemicals like diacetyl known to scar and narrow your airways permanently. The damage leads E cigarette flavorings may damage cilia production and function Harvard Gazette