Comprehensive Study of E-Cigarettes

While e-cigarettes sometimes helping people quit smoking (which is one of the leading causes of preventable death) is beneficial, a lot of them do contain chemicals that are clearly toxic. These chemicals are probably less harmful than the chemicals in other cigarettes, but the supposition that e-cigarettes aren’t harmful (periodically found among misinformed youth) shouldn’t be perpetuated.

A new congressionally mandated report from the National Academies of Sciences, Engineering, and Medicine takes a comprehensive look at evidence on the human health effects of e-cigarettes. Although the research base is limited given the relatively short time e-cigarettes have been used, the committee that conducted the study identified and examined over 800 peer-reviewed scientific studies, reaching dozens of conclusions about a range of health impacts.

Evidence suggests that while e-cigarettes are not without health risks, they are likely to be far less harmful than conventional cigarettes, the report says. They contain fewer numbers and lower levels of toxic substances than conventional cigarettes, and using e-cigarettes may help adults who smoke conventional cigarettes quit smoking. However, their long-term health effects are not yet clear. Among youth — who use e-cigarettes at higher rates than adults do — there is substantial evidence that e-cigarette use increases the risk of transitioning to smoking conventional cigarettes.

E-cigarettes are a diverse group of products containing a heating element that produces an aerosol from a liquid that users can inhale via a mouthpiece, and include a range of devices such as “cig-a-likes,” vape tank systems, and vape mods. Millions of Americans use e-cigarettes, and e-cigarette use is generally greatest among young adults and decreases with age. Use varies substantially across demographic groups, including age, gender, race, and ethnicity. For example, among youth and adults, use is typically greater among males than females.

Whether e-cigarettes have an overall positive or negative impact on public health is currently unknown, the report says. More and better research on e-cigarettes’ short- and long-term effects on health and on their relationship to conventional smoking is needed to answer that question with clarity.

“E-cigarettes cannot be simply categorized as either beneficial or harmful,” said David Eaton, chair of the committee that wrote the report, and dean and vice provost of the Graduate School of the University of Washington, Seattle. “In some circumstances, such as their use by non-smoking adolescents and young adults, their adverse effects clearly warrant concern. In other cases, such as when adult smokers use them to quit smoking, they offer an opportunity to reduce smoking-related illness.”

The report offers conclusions about e-cigarette use and a range of health impacts, including the following, and it notes the strength of the evidence for each conclusion.

Exposure to nicotine

  • There is conclusive evidence that exposure to nicotine from e-cigarettes is highly variable and depends on the characteristics of the device and the e-liquid, as well as on how the device is operated.
  • There is substantial evidence that nicotine intake from e-cigarettes among experienced adult e-cigarette users can be comparable to that from conventional cigarettes.

Exposure to toxic substances

  • There is conclusive evidence that in addition to nicotine, most e-cigarettes contain and emit numerous potentially toxic substances.
  • There is substantial evidence that except for nicotine, exposure to potentially toxic substances from e-cigarettes (under typical conditions of use) is significantly lower compared with conventional cigarettes.

[…]