Particulate Matter from Electronic Cigarettes and Conventional Cigarettes: a Systematic Review and Observational Study

Curr Environ Health Rep. 2015 Dec;2(4):423-9. doi: 10.1007/s40572-015-0072-x.


Objectives: The aim of this study is to review the literature on the composition of aerosols from electronic cigarettes (e-cigarettes) originated by human vaping and to describe the emission of particulate matter ≤ 2.5 μm in diameter (PM(2.5)) from conventional and e-cigarettes at home in real-use conditions.

Methods: We conducted a systematic literature search in PubMed and Web of Science. We measured PM(2.5) in four different homes: one from a conventional cigarette smoker, one from an e-cigarette user, and two from non-smokers.

Results: The review identified eight previous investigations on the composition of aerosols from e-cigarettes originated by human vaping and indicated that emissions from e-cigarettes can contain potential toxic compounds such as nicotine, carbonyls, metals, and organic volatile compounds, besides particulate matter. In the observational study, the PM(2.5) median concentration was 9.88 μg/m³ in the e-cigarette user home and 9.53 and 9.36 μg/m³ in the smoke-free homes, with PM(2.5) peaks concurrent with the e-cigarette puffs.

Conclusion: Both the literature review and the observational study indicate that e-cigarettes used under real-conditions emit toxicants, including PM(2.5). Further research is needed to characterize the chemicals emitted by different types of e-cigarettes and to assess secondhand exposure to e-cigarette aerosol using biological markers.

Keywords: E-cigarette; Electronic cigarette; Electronic nicotine delivery system; Particulate matter; Tobacco smoke pollution.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review
  • Systematic Review

MeSH terms

  • Aerosols / chemistry*
  • Air Pollution, Indoor / analysis
  • Electronic Nicotine Delivery Systems*
  • Environmental Monitoring / methods
  • Hazardous Substances
  • Humans
  • Nicotine / analysis
  • Particulate Matter / analysis*
  • Particulate Matter / chemistry
  • Tobacco Products / analysis*
  • Volatile Organic Compounds / analysis


  • Aerosols
  • Hazardous Substances
  • Particulate Matter
  • Volatile Organic Compounds
  • Nicotine