Propylene glycol, a component of electronic cigarette liquid, damages epithelial cells in human small airways Respiratory Research Springer Nature Link Understanding the Dangers of Vaping Prevention Poster An updated overview of e cigarette impact on human health Respiratory Research Springer Nature Link e Cigarettes Safety Not Yet Proven CANSA The Cancer Association of South Africa CANSA The Cancer Association of South Africa Flavorants and Propylene Glycol From e Cigarettes Form Harmful Irritants When Combined AJMC Liquid E Cigarettes Liquid nicotine used in e cigarettes still a danger to children despite recent