How close are we to definitively identifying the respiratory health effects of e-cigarettes?

Abstract

Use of electronic cigarettes (e-cigarettes) is frequently promoted as a less harmful alternative to cigarette smoking. The impact of repeated inhalation of e-cigarette aerosols on respiratory health is not well understood. Areas covered: Using results from laboratory, observational, and clinical studies, we synthesize evidence relevant to potential respiratory health effects that may result from inhalation of e-cigarette aerosols. Expert commentary: Chemical analyses reveal that e-cigarette aerosols contain numerous respiratory irritants and toxicants. There are documented cytotoxic effects of e-cigarette constituents on lung tissue. Studies among ex-smokers who switched to e-cigarettes note reduced exposure to numerous respiratory toxicants, reduced asthma exacerbations, and chronic obstructive pulmonary disease symptoms. Regular exposure to e-cigarette aerosols is associated with impaired respiratory functioning. Potential respiratory health risks resulting from secondhand e-cigarette aerosol exposure have not been sufficiently evaluated. Current evidence indicates that although e-cigarettes are not without risk, these products seemingly pose fewer respiratory health harms issues compared to tobacco cigarettes. Data from prospective studies and randomized controlled trials examining the impact of e-cigarette use on lung health are needed to better understand respiratory health risks tied to use of these products.

Association of smoking and electronic cigarette use with wheezing and related respiratory symptoms in adults: cross-sectional results from the Population Assessment of Tobacco and Health (PATH) study, wave 2

“…E-cigarette is a device to heat and vaporise a liquid mixture that contains nicotine, propylene glycol, glycerin and flavourings to generate an aerosol inhaled by the users 5. Chemical analysis of e-cigarettes aerosols identified respiratory irritants and toxicants, regular exposures to which are associated with impaired respiratory functioning 6 7. Our recent study on effects of e-cigarettes flavouring chemicals on inflammatory and oxidative response using human monocytic cell lines showed biologically significant inflammatory response due to e-cigarette flavouring chemicals,8 9 providing plausibility for the association.…”

“…Asthma and chronic obstructive pulmonary disease are the most common causes of recurrent wheezing 14. Several studies have focused on associations of e-cigarettes use with wheezing or whistling and reported mixed results 7–9 12 15–23. One study on 2086 Southern California Children’s Health Study adolescent participants found e-cigarettes use increased risks of chronic bronchitis symptoms in teens while no significant association of e-cigarettes use with wheeze were found in teens after adjusting for cigarettes use 21.…”

The Value of Providing Smokers with Free E-Cigarettes: Smoking Reduction and Cessation Associated with the Three-Month Provision to Smokers of a Refillable Tank-Style E-Cigarette

“…Quitting smoking at the soonest opportunity is the best action a person can take to improve their health in the medium to long-term (3). Given that most of the 8 million smoking-related deaths projected to occur globally by 2030 will be among current, not prospective smokers (4), developing new effective ways of helping people to quit smoking is a public health imperative.…”

“…Whilst it is widely accepted that e-cigarettes are substantially less harmful than combustible cigarettes, nevertheless these devices are not risk or harm free. Along with the uncertainty regarding the health impact of long term e-cigarette use concerns have also been raised as to more immediate cardio vascular and other health harms that have been linked to e-cigarette use (3,4). Whilst recognizing that complete cessation of all tobacco and nicotine use is the best action smokers can take to improve their health, the Royal College of Physicians and Public Health England have both indicated the likely benefit of those smokers who are either unable or unwilling to quit smoking combustible tobacco products to consider switching to using non-tobacco nicotine products.…”

The Value of Providing Smokers with Free E-Cigarettes: Smoking Reduction and Cessation Associated with the Three-Month Provision to Smokers of a Refillable Tank-Style E-Cigarette

“…Whilst it is widely accepted that e-cigarettes are substantially less harmful than combustible cigarettes, nevertheless, these devices are not risk or harm-free. Along with the uncertainty regarding the health impact of long-term e-cigarette use, concerns have also been raised as to more immediate cardiovascular and other health harms that have been linked to e-cigarette use [ 6 , 7 ]. Although it is widely acknowledged that the complete cessation of all tobacco and nicotine use is the best action that smokers can take to improve their health, the Royal College of Physicians and Public Health England have both indicated the likely benefit of switching to the exclusive use of vaping devices for those smokers who are unable or unwilling to quit smoking combustible tobacco products.…”