Cigarette Smokers Versus Cannabis Smokers Versus Co-users of Cigarettes and Cannabis: A Pilot Study Examining Exposure to Toxicants

Research output: Contribution to journalArticlepeer-review

4 Scopus citations


INTRODUCTION: Studies suggest tobacco and cannabis co-users may experience greater toxicant exposure than exclusive cigarette (ET) smokers. No study has systematically tested differences in toxicant exposure among co-users, exclusive cannabis (ECa) smokers, and ET smokers.

AIMS AND METHODS: Adult daily cigarette smokers and/or weekly cannabis smokers completed two laboratory visits. Co-users (n = 19) tested positive for urinary 11-nor-9-carboxy-Δ 9-tetrahydrocannabinol (THCCOOH), self-reported cannabis use ≥1 per week, and smoked ≥5 cigarettes per day (CPD). ET smokers (n = 18) denied past month cannabis use, tested negative for urinary THCCOOH and smoked ≥5 CPD. ECa smokers (n = 16) tested positive for urinary THCCOOH, self-reported cannabis use ≥1 per week, and denied past month tobacco use (NicAlert <3). Self-reported tobacco and cannabis use were collected at both visits. First morning urinary tobacco and combustion-related biomarkers of exposure were compared following a cannabis or tobacco smoking session (visit 2).

RESULTS: Co-users and ET smokers had higher levels of exhaled carbon monoxide, total nicotine equivalents, metabolites of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNAL), and all four measured mercapturic acids (measures of volatile organic compounds) than ECa smokers (ps < .005). ET smokers (geometric mean = 7220.2 pmol/mg) had higher levels of 2-hydroxypropylmercapturic acid than co-users (geometric mean = 5348.7 adjusted p = .009). Phenanthrene tetraol did not differ by group (p > .05).

CONCLUSIONS: Co-users and ET smokers demonstrated comparable levels of biomarkers of exposure to harmful constituents despite smoking similar amounts of tobacco. ECa smokers demonstrated lower levels of toxicant exposure for most biomarkers.

IMPLICATIONS: Although ECa smokers are exposed to significantly lower levels of harmful constituents compared with co-users and exclusive cigarette smokers, this group is still exposed to higher levels of toxicants than observed in studies of nonsmokers. Additionally, these three groups were exposed to similar levels of phenanthrene tetraol. It is important to account for cannabis use in studies examining biomarkers of exposure among cigarette smokers. Additionally, further research is needed examining exposure to harmful chemicals among various types of cannabis and tobacco users.

Original languageEnglish (US)
Pages (from-to)125-129
Number of pages5
JournalNicotine and Tobacco Research
Issue number1
StatePublished - Jan 1 2022

Bibliographical note

Publisher Copyright:
© 2021 The Author(s). Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved.


  • Adult
  • Biomarkers
  • Cannabis
  • Electronic Nicotine Delivery Systems
  • Humans
  • Pilot Projects
  • Smokers
  • Tobacco Products

PubMed: MeSH publication types

  • Research Support, Non-U.S. Gov't
  • Journal Article
  • Research Support, N.I.H., Extramural


Dive into the research topics of 'Cigarette Smokers Versus Cannabis Smokers Versus Co-users of Cigarettes and Cannabis: A Pilot Study Examining Exposure to Toxicants'. Together they form a unique fingerprint.

Cite this