What Do We Know About the Harms of Electronic Cigarettes?

Electronic cigarettes are commonly misperceived as safe, hence the importance of health care providers understanding the harms of these devices. To date, there is substantial evidence of impaired immune defenses leading to increased risk for severe infections. Electronic cigarette users have increased respiratory symptoms, including bronchitis, cough, and wheeze. There is evidence of emphysema from electronic cigarette use in both laboratory mouse studies and population health surveys. There is evidence of increased cardiovascular disease from electronic cigarettes in both laboratory mouse models and population health surveys. There have been many cases of acute severe lung disease leading to hospitalization and death in electronic cigarette users; although most cases reported were associated with vitamin E acetate in tetrahydrocannabinol-containing products, some cases report exclusive use of nicotine-containing electronic cigarettes. Recently, constrictive bronchiolitis has been found in lung biopsies of electronic cigarette users with dyspnea. There are multiple carcinogenic chemicals in electronic cigarette emissions. Mouse models demonstrate increased rates of lung cancer and carcinogenic chemicals accumulate in the urine of human users. Neurotoxicity has been demonstrated in laboratory mouse models. There is concern about nicotine exposure adversely impacting brain development and serving as a gateway drug for other harmful drug use. Dual use of electronic and combustible cigarettes appears to be more harmful than the use of combustible cigarettes alone. Electronic cigarettes have substantial harms and are not a safe alternative to combustible tobacco use. It is important for health care providers to know these harms and counsel their patients.