ACS Publications. Most Trusted. Most Cited. Most Read
My Activity
CONTENT TYPES

Figure 1Loading Img
RETURN TO ISSUEPREVCorrespondence/Rebut...Correspondence/RebuttalNEXT

Response to Comment on “Flavoring Compounds Dominate Toxic Aldehyde Production during E Cigarette Vaping”

View Author Information
Desert Research Institute, Department of Atmospheric Sciences, Desert Research Institute, Reno, Nevada 89512, United States
*Phone +1-775-6747084; e-mail: [email protected] and phone.
Cite this: Environ. Sci. Technol. 2017, 51, 4, 2493–2494
Publication Date (Web):February 7, 2017
https://doi.org/10.1021/acs.est.7b00163

Copyright © 2017 American Chemical Society. This publication is available under these Terms of Use.

  • Free to Read

Article Views

924

Altmetric

-

Citations

LEARN ABOUT THESE METRICS
PDF (181 KB)

In their letter, Farsalinos et al. state that our findings are in “a stark contrast” to previously reported results. The authors of the letter take issue with both the absolute aldehyde levels and the differences between these levels in flavored and unflavored e-cigarette vapors that we observed in our study. Their assertions, however, directly contradict what has been actually reported in peer-reviewed publications, including those cited in the letter.

For example, Farsalinos et al. claim that our assessment of Gillman et al. (1) results is incorrect. In our paper (page 13 084), we provide a summary of Gillman et al. results for the same e-cigarette type that was used in our study (“brand III”). Accepting that Gillman et al. mistyped the glycol and glycerol content in their paper and neglecting the fact that they used a higher e-cigarette power, it is still undeniable that our results for unflavored e-liquids for this brand (0.64 ± 0.22 μg/puff) are statistically within the range of formaldehyde concentrations Gillman et al. reported for their liquid (8.5 ± 8.9 μg/puff). We accept the possibility that Gillman et al. have produced, inadvertently, some dry puffs in their experiments that caused occasionally high (about 10 times higher than what we have observed) aldehyde concentrations and, thus, a very large experimental variability for the unflavored liquid they tested. This, however, tends to support our observations that showed lower concentrations (i.e., free of dry puffs), rather than disprove them. It should be also noted that, contrary to the Farsalinos et al. assertion, Gillman et al. (1) did not “explain that the high level of aldehydes emitted from some of the e-cigarette devices were the result of overheating and dry puffs”. They have only “hypothesized” this possibility for the highest e-cigarette power and, in the last sentence of the Discussion section in Gillman et al., (1) state explicitly that “determination of dry-puffs is outside of the scope” of their study.

Further, Farsalinos et al. state that Kosmider et al. (2) “found minimal differences in aldehyde emissions between ten commercially available flavored liquids and three unflavored liquids”. Yet, Table 2 of Kosmider et al. clearly shows that, with the exception of butanal, detectable concentrations of formaldehyde and other aldehydes are found only in flavored liquids. This is the opposite of what Farsalinos et al. claim in the letter.

Farsalinos et al. argue that “previous studies have found high aldehyde levels under dry puff conditions in liquids without added flavor. (3) This is expected since aerosolizing 13C-labelled propylene glycol and glycerol results in 13C-labelled aldehyde emissions.” (4) It is puzzling why this argument is brought up in the context of criticizing our paper. On page 13 084 we clearly state “that our results do not suggest that PG or VG produces no aldehydes, but that flavoring compounds are responsible for the main part of the emitted toxic aldehydes” and that “by collecting more puffs per measurement, we could have quantified emissions for unflavored liquids”. Keeping in mind that Spenser and Lauterbach (4) is not a peer-reviewed paper, but a brief conference abstract, that study does not in any way disprove the role of flavorings in aldehyde production, as they have not been investigated in that study (at least, they are not mentioned in the abstract).

Aldehyde concentrations observed in our study are within the range reported in the peer-reviewed literature, as is discussed in our paper. We are certain the authors of the letter know that aldehyde emissions depend strongly on e-cigarette construction and power (1-3) and can be compared only for the same e-cigarette construction and power output. As discussed above, our results compare favorably under such criteria with Gillman et al. (1) study. It should be also noted that our results are not, by far, the highest reported in the literature. For example, our highest observations are 2–7 times lower than those reported by Sleiman et al. (5) Farsalinos et al. dismiss this fact by speculating that this “can also be explained by overheating and dry puffs” in Sleiman et al. experiments. Unfortunately, Farsalinos et al. provide no arguments to support their critique of Sleiman and co-workers experimental setup.

Despite the fact that the arguments Farsalinos et al. make are clearly misplaced, misleading, and self-contradictory, we welcome any attempts to reproduce our study on the effect of flavoring compounds on aldehyde formation during vaping. The need for verifying experimental results is not limited to just our study, however. Farsalinos et al. seem to dismiss any study that reports high aldehyde concentrations in e-cigarette vapors by speculating that high concentrations occur only in dry puff conditions. The assertion that high aldehyde concentrations occur only during dry puff conditions, which would be avoided by e-cigarette users, is based on a single paper by the lead author of the letter. (3) While that study has been criticized elsewhere, (6) it remains unverified so far. Currently, we are conducting a study on secondary aldehyde emissions during vaping, in which e-cigarette users are asked to vape as they usually do using their own device and liquid. In all subjects, we observed a significant increase in aldehyde concentrations in exhaled e-cigarette vapors relative to baseline levels. For example, formaldehyde and acetaldehyde concentrations increased relative to the baseline by up to 0.4 μg and 0.6 per exhaled puff (breath), respectively. These values are comparable to the emissions per puff that we observed in our study. Given that aldehydes are very water-soluble, exhaled concentrations are likely to underestimate significantly the actual intake concentrations. Yet, none of the users complained of dry puffs or any unpleasant sensations. This clearly contradicts findings reported by Farsalinos et al. (3) and asks for further research in this area. Given the importance of the topic of e-cigarette safety, we urge the research community to verify any study on e-cigarettes, including those by Farsalinos et al., (3) Gillman et al., (1) and others.

Author Information

ARTICLE SECTIONS
Jump To

  • Corresponding Author
  • Author
    • Vera Samburova - Desert Research Institute, Department of Atmospheric Sciences, Desert Research Institute, Reno, Nevada 89512, United States
  • Notes
    The authors declare no competing financial interest.

References

ARTICLE SECTIONS
Jump To

This article references 6 other publications.

  1. 1
    Gillman, I. G.; Kistler, K. A.; Stewart, E. W.; Paolantonio, A. R. Effect of variable power levels on the yield of total aerosol mass and formation of aldehydes in e-cigarette aerosols Regul. Toxicol. Pharmacol. 2016, 75, 58 65 DOI: 10.1016/j.yrtph.2015.12.019
  2. 2
    Kosmider, L.; Sobczak, A.; Fik, M.; Knysak, J.; Zaciera, M.; Kurek, J.; Goniewicz, M. L. Carbonyl Compounds in Electronic Cigarette Vapors: Effects of Nicotine Solvent and Battery Output Voltage Nicotine Tob. Res. 2014, 16, 1319 1326 DOI: 10.1093/ntr/ntu078
  3. 3
    Farsalinos, K. E.; Voudris, V.; Poulas, K. E-cigarettes generate high levels of aldehydes only in ’dry puff’ conditions Addiction 2015, 110, 1352 1356 DOI: 10.1111/add.12942
  4. 4
    Spencer, A.; Lauterbach, J. H. Generation of Acetaldehyde and Other Carbonyl Compounds during Vaporization of Glycerol and Propylene Glycol during Puffing of a Popular Style of E-Cigarette. 54th Meeting of the Society of Toxicology, 2015. Abstract 188. https://www.toxicology.org/pubs/docs/Tox/2015Tox.pdf.
  5. 5
    Sleiman, M.; Logue, J. M.; Montesinos, V. N.; Russell, M. L.; Litter, M. I.; Gundel, L. A.; Destaillats, H. Emissions from Electronic Cigarettes: Key Parameters Affecting the Release of Harmful Chemicals Environ. Sci. Technol. 2016, 50, 9644 9651 DOI: 10.1021/acs.est.6b01741
  6. 6
    Shihadeh, A.; Talih, S.; Eissenberg, T. Commentary on Farsalinos et al. (2015) : E-cigarettes generate high levels of aldehydes only in ‘dry puff’ conditions. Addiction 2015, 110, 1861 1862, DOI:  DOI: 10.1111/add.13066 .

Cited By

ARTICLE SECTIONS
Jump To

This article is cited by 6 publications.

  1. Skylar Klager, Jose Vallarino, Piers MacNaughton, David C. Christiani, Quan Lu, and Joseph G. Allen . Flavoring Chemicals and Aldehydes in E-Cigarette Emissions. Environmental Science & Technology 2017, 51 (18) , 10806-10813. https://doi.org/10.1021/acs.est.7b02205
  2. Sebastien Soulet, Roberto A. Sussman. Critical Review of the Recent Literature on Organic Byproducts in E-Cigarette Aerosol Emissions. Toxics 2022, 10 (12) , 714. https://doi.org/10.3390/toxics10120714
  3. Penelope Truman, Stephen Stanfill, Ali Heydari, Elana Silver, Jefferson Fowles. Monoamine oxidase inhibitory activity of flavoured e-cigarette liquids. NeuroToxicology 2019, 75 , 123-128. https://doi.org/10.1016/j.neuro.2019.09.010
  4. Robert M. Strongin. E-Cigarette Chemistry and Analytical Detection. Annual Review of Analytical Chemistry 2019, 12 (1) , 23-39. https://doi.org/10.1146/annurev-anchem-061318-115329
  5. William E Stephens. Comparing the cancer potencies of emissions from vapourised nicotine products including e-cigarettes with those of tobacco smoke. Tobacco Control 2018, 27 (1) , 10-17. https://doi.org/10.1136/tobaccocontrol-2017-053808
  6. Alexander N. Larcombe, Maxine A. Janka, Benjamin J. Mullins, Luke J. Berry, Arne Bredin, Peter J. Franklin. Reply to “Letter to the Editor: The effects of electronic cigarette aerosol exposure on inflammation and lung function in mice”. American Journal of Physiology-Lung Cellular and Molecular Physiology 2017, 313 (5) , L970-L971. https://doi.org/10.1152/ajplung.00448.2017
  • This publication has no figures.
  • References

    ARTICLE SECTIONS
    Jump To

    This article references 6 other publications.

    1. 1
      Gillman, I. G.; Kistler, K. A.; Stewart, E. W.; Paolantonio, A. R. Effect of variable power levels on the yield of total aerosol mass and formation of aldehydes in e-cigarette aerosols Regul. Toxicol. Pharmacol. 2016, 75, 58 65 DOI: 10.1016/j.yrtph.2015.12.019
    2. 2
      Kosmider, L.; Sobczak, A.; Fik, M.; Knysak, J.; Zaciera, M.; Kurek, J.; Goniewicz, M. L. Carbonyl Compounds in Electronic Cigarette Vapors: Effects of Nicotine Solvent and Battery Output Voltage Nicotine Tob. Res. 2014, 16, 1319 1326 DOI: 10.1093/ntr/ntu078
    3. 3
      Farsalinos, K. E.; Voudris, V.; Poulas, K. E-cigarettes generate high levels of aldehydes only in ’dry puff’ conditions Addiction 2015, 110, 1352 1356 DOI: 10.1111/add.12942
    4. 4
      Spencer, A.; Lauterbach, J. H. Generation of Acetaldehyde and Other Carbonyl Compounds during Vaporization of Glycerol and Propylene Glycol during Puffing of a Popular Style of E-Cigarette. 54th Meeting of the Society of Toxicology, 2015. Abstract 188. https://www.toxicology.org/pubs/docs/Tox/2015Tox.pdf.
    5. 5
      Sleiman, M.; Logue, J. M.; Montesinos, V. N.; Russell, M. L.; Litter, M. I.; Gundel, L. A.; Destaillats, H. Emissions from Electronic Cigarettes: Key Parameters Affecting the Release of Harmful Chemicals Environ. Sci. Technol. 2016, 50, 9644 9651 DOI: 10.1021/acs.est.6b01741
    6. 6
      Shihadeh, A.; Talih, S.; Eissenberg, T. Commentary on Farsalinos et al. (2015) : E-cigarettes generate high levels of aldehydes only in ‘dry puff’ conditions. Addiction 2015, 110, 1861 1862, DOI:  DOI: 10.1111/add.13066 .

Pair your accounts.

Export articles to Mendeley

Get article recommendations from ACS based on references in your Mendeley library.

Pair your accounts.

Export articles to Mendeley

Get article recommendations from ACS based on references in your Mendeley library.

You’ve supercharged your research process with ACS and Mendeley!

STEP 1:
Click to create an ACS ID

Please note: If you switch to a different device, you may be asked to login again with only your ACS ID.

Please note: If you switch to a different device, you may be asked to login again with only your ACS ID.

Please note: If you switch to a different device, you may be asked to login again with only your ACS ID.

MENDELEY PAIRING EXPIRED
Your Mendeley pairing has expired. Please reconnect