Electronic cigarettes and lung toxicity
The use of electronic cigarettes (e-cigarettes) in the United States has steadily increasedsince their introduction into the market in 2007. These devices deliver nicotine through thevaporization of a liquid which contains a vehicle (propylene glycol or glycerin), artificialflavoring, and nicotine. The combustion of these liquids creates a vapor containing particulates,multiple chemicals, and nicotine. The long-term safety of these products is unknown. Studiesin healthy, non-smoking volunteers and smokers with no clinical pulmonary disease havedemonstrated that the inhalation of e-cigarette vapor has minimal short-term effects onpulmonary function. The exposure of cell cultures to e-cigarette liquid or aerosols has beenshown to reduce cell viability, induce cytokine production, and cause oxidative stress. Theexposure of animals (mice and rats) to e-cigarette aerosols induces inflammatory responsesin the lungs and delays the clearance of bacterial and viral challenges. There are a smallnumber of case reports of patients developing acute pulmonary toxicity following the use ofe-cigarettes. Two patients have developed lipoid pneumonia following the use of e-cigarettesfor 3 and 7 months. Finally, several studies suggest that patients with chronic lung diseasewho switch from tobacco cigarettes to e-cigarettes can have improvement in lung function(asthmatics) and a reduction in the number of exacerbations (chronic obstructive pulmonarydisease). Clearly, the public and the medical profession need more information about thelong-term complications associated with the use of e-cigarettes and their benefit in smokingcessation efforts.Keywords: electronic