Potential risk of carcinogens in e-cigarette vapour

Albeit in lower concentrations than in cigarette smoke, e-cigarette solutions contain carcinogens such as formaldehyde and acetaldehyde, which are present in much greater concentrations when high voltage devices are used. 2 In addition to the risk of oral and lung cancer from inhalation of these compounds, in preclinical experimental models e-cigarette vapour is associated with increased inflammation, oxidative stress, and disruption of endothelial barrier function. 3 Furthermore, these effects on the airway may promote allergen induced airway hyper-reactivity. 4 They may also predispose people to respiratory virus and bacterial infection by impairing immune function and enhancing the virulence of pathogens such as meticillin resistant Staphylococcus aureus. 5 6 7 Further basic science and epidemiological research is needed to increase our evidence base on the benefits and harms of e-cigarette vapour.