Yet Another Study Reports Vaping-Associated Health Risks

Vaping, or use of e-cigarettes, is an increasingly popular alternative to cigarette smoking. Last week, Action on Smoking and Health published an estimate that 3.2 million people in the UK are using e-cigarettes in 2018, compared to just 700,000 users 6 years ago.[i]

We have reported on the use of e-cigarettes and potential health effects in editions 111 (here), 123 (here), 173 (here), 217 (here) and 224 (here) of BC Disease News. In this article, we analyse the results of a new study, which found that cancer-causing chemicals are retained in the lungs after e-cigarettes are used.[ii]

Researchers were specifically looking for the presence of aldehyde and ketone chemicals, such as formaldehyde and acetaldehyde. To date, ‘… the only research on the respiratory uptake of aldehydes during smoking has been done on conventional cigarette users’.[iii]

Formaldehyde is classified by the International Agency for Research on Cancer as ‘carcinogenic to humans’,[iv] and acetaldehyde is classified as ‘possibly carcinogenic to humans’ (though acetaldehyde as a by-product of alcohol consumption is classified as ‘carcinogenic to humans’)[v].

12 e-cigarette users participated in the latest e-cigarette study.

Chemical concentrations, in the participants’ breath, were measured both before and after vaping. In doing so, the researchers were able to investigate how chemical levels fluctuated in users over the course of a ‘vaping session’.

Further, chemical concentrations in e-cigarette emissions were measured. The difference between chemical concentrations of post-vaping breath and the total chemical content of e-cigarette vapour constituted the residual chemical concentrations within the participants’ lungs.

In most cases, aldehyde levels were significantly higher in post-vaping exhaled breath than in pre-vaping exhaled breath. This suggests that chemicals are inhaled and withheld by the body during a ‘vaping session’

In fact, a large volume (more than 90%) of inhaled chemicals were retained by the lungs.

Lead author, Vera Samburova, Ph.D. summarised the study findings, as follows:

Little is known about this process for e-cigarette use, and understanding the unique risks vaping poses to users is critical in determining toxicological significance. We found that the average concentration of aldehydes in the breath after vaping sessions was about ten and a half times higher than before vaping. Beyond that, we saw that the concentration of chemicals like formaldehyde in the breath after vaping was hundreds of times lower than what is found in the direct e-cigarette vapors, which suggests that a significant amount is being retained in the user's respiratory tract’.

This study was only a pilot and is therefore limited in having only observed a small cohort of participants. In principle, however, the findings demonstrate that aldehydes (specifically formaldehyde) in e-cigarette vapour are deposited into the users’ airways. 

If future studies confirm that e-cigarette use results in the retention of cancer-causing compounds in the lungs, history of e-cigarette use in occupational cancer (especially lung cancer) claimants should be taken into consideration, for medical causation purposes.


[i] ‘Number of vapers tops 3 million for first time in Britain’ (14 September 2018 Cancer Research UK) <> accessed 19 September 2018.

[ii]  Samburova, V. et al. Aldehydes in Exhaled Breath during E-Cigarette Vaping: Pilot Study Results. Toxics 6, (2018). (Accessed 17 September 2018)

[iii] Desert Research Institute. "Significant amount of cancer-causing chemicals stays in lungs during e-cigarette use: Formaldehyde and other chemicals absorbed by respiratory tract during vaping sessions." ScienceDaily. ScienceDaily, 10 September 2018. <> accessed 17 September 2018.

[iv] IARC classifies formaldehyde as carcinogenic to humans.  International Agency for Research on Cancer, Press Release 153, 15 June 2004. (Accessed 17 September 2018)

[v] Agents Classified by the IARC Monographs, Volumes 1-122. (Accessed 17 September 2018)