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Biomarkers of Carcinogens in e-Cigarette Vapers vs Cigarette Smokers

MedicalResearch.com Interview with:

Dr. Daisy Dai

Dr. Dai

Dr. Hongying Daisy Dai, PhD
Professor and Associate Dean of Research
The College of Public Health
University of Nebraska Medical Center.

MedicalResearch.com: What is the background for this study?

Response: Tobacco use landscape has been changing in the United States with fewer combustible cigarette smokers and more e-cigarette and other emerging tobacco users. Nicotine concentration level is a key product characteristic of modern e-cigarette products and high-nicotine vaping devices have recently become available. This study seeks to examine whether biomarkers of exposure to tobacco-related toxicants have changed since 2013 among adult nicotine e-cigarette users, non-nicotine e-cigarette users, and cigarette smokers.

MedicalResearch.com: What are the main findings?

Response:  This study focused on urinary nicotine metabolites and tobacco-specific nitrosamines, which are biomarkers of exposure to tobacco-related toxicants implicated in nicotine addiction and cancer risk. The main findings are:

  • Nicotine vapers were more likely to vape daily and reported a higher number of puffs than non-nicotine vapers.
  • Nicotine metabolites, as measured by TNE2, nearly doubled from 2013-2014 to 2018-2019. Although nicotine metabolites were also generally lower in nicotine vapers than smokers, this difference decreased over time.
  • NNAL, a carcinogen metabolite, was consistently lower in nicotine vapers than smokers. 

MedicalResearch.com: What should readers take away from your report?


  • The lower NNAL level in both nicotine and non-nicotine vapers versus smokers suggests that e-cigarettes might represent a reduced health risk than cigarette smoking. Therefore, switching completely from combustible cigarettes to e-cigarettes may provide significant health benefits.
  • However, e-cigarette use is not harmless, and the increasing trend of cotinine levels found in this study is likely due to the proliferation of vaping products containing high nicotine concentrations and nicotine salt formulations with increased palatability. E-cigarette products with high nicotine concentrations might pose higher risks of addiction, especially for young people and never smokers.

MedicalResearch.com: What recommendations do you have for future research as a results of this study?

Response: It will be important to continue to monitor the biomarkers of e-cigarette users at the population level and understand the health effects of different nicotine concentrations in e-cigarettes.

I have no conflicts of interest to disclose.


Dai HD, Leventhal AM, Khan AS. Trends in Urinary Biomarkers of Exposure to Nicotine and Carcinogens Among Adult e-Cigarette Vapers vs Cigarette Smokers in the US, 2013-2019. JAMA. 2022;328(18):1864–1866. doi:10.1001/jama.2022.14847

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Last Updated on November 9, 2022 by Marie Benz MD FAAD