Vaping, Environmental Toxicants Exposure, and Lung Cancer Risk

Our plain-English summary of Vaping, Environmental Toxicants Exposure, and Lung Cancer Risk, by S.A. Shehata, E.A. Toraih, E.A. Ismail, et al (Cancers, 2023).

The study

• Authors: S.A. Shehata, E.A. Toraih, E.A. Ismail, A.M. Hagras, E. Elmorsy, M.S. Fawzy
• Journal: Cancers
• Published: 2023;15(18)
• Type of article: Review
• Cited by: 66 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Lung cancer (LC) is the second-most prevalent tumor worldwide. According to the most recent GLOBOCAN data, over 2.2 million LC cases were reported in 2020, with an estimated new death incident of 1,796,144 lung cancer cases. Genetic, lifestyle, and environmental exposure play an important role as risk factors for LC. E-cigarette, or vaping, products (EVPs) use has been dramatically increasing world-wide. There is growing concern that EVPs consumption may increase the risk of LC because EVPs contain several proven carcinogenic compounds. However, the relationship between EVPs and LC is not well established. E-cigarette contains nicotine derivatives (e.g., nitrosnornicotine, nitrosamine ketone), heavy metals (including organometal compounds), polycyclic aromatic hydrocarbons, and flavorings (aldehydes and complex organics). Several environmental toxicants have been proven to contribute to LC. Proven and plausible environmental carcinogens could be physical (ionizing and non-ionizing radiation), chemicals (such as asbestos, formaldehyde, and dioxins), and heavy metals (such as cobalt, arsenic, cadmium, chromium, and nickel). Air pollution, especially particulate matter (PM) emitted from vehicles and industrial exhausts, is linked with LC. Although extensive environmental exposure prevention policies and smoking reduction strategies have been adopted globally, the dangers remain. Combined, both EVPs and toxic environmental exposures may demonstrate significant synergistic oncogenicity. This review aims to analyze the current publications on the importance of the relationship between EVPs consumption and environmental toxicants in the pathogenesis of LC.

In plain English

This article was a narrative review, not an original study. The authors searched Scopus, PubMed and Web of Science for published research on vaping (e-cigarette) products, environmental toxicants and lung cancer. They did not report search dates, how many studies they included, or how studies were chosen. The review described possible cancer-causing ingredients in vaping products. It also surveyed environmental exposures: radon and medical radiation, air pollution, heavy metals, asbestos and pesticides. Its asbestos section cited other sources. These stated that 125 million people worldwide are exposed to asbestos, and that high levels of asbestos are the primary cause of 5% to 7% of lung cancer cases worldwide, mainly through work. The section also cited a cohort study reporting a 14.4-fold increased risk for asbestos combined with tobacco use. The review named no asbestos fiber types. The authors stated that the relationship between vaping and lung cancer is not well established. They concluded that chemicals found in both vaping products and the environment may disrupt lung function and start cancer in an additive or synergistic way, and they called for more research.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Narrative review of published literature (database search; no stated inclusion criteria, dates or study count)
• Who was studied: No study population of its own; the review drew on published human, animal and cell studies and agency reports found in Scopus, PubMed and Web of Science
• Exposure: Vaping products (nicotine-derived nitrosamines, propylene glycol and vegetable glycerin, flavorings, cannabidiol, vitamin E acetate, metals) and environmental toxicants: radon and medical radiation, particulate air pollution, cadmium and arsenic, asbestos (no fiber types named), and organophosphate pesticides
• Main results:
  • The review cited a WHO estimate that 125 million people worldwide are exposed to asbestos, which can lead to lung cancer, laryngeal cancer and mesothelioma (a finding of the cited source, not of this review)
  • The review cited a source stating that high levels of asbestos are the primary cause of between 5% and 7% of all reported lung cancer cases worldwide, chiefly due to occupational exposure
  • The review cited a cohort study reporting a 14.4-fold increased lung cancer risk for asbestos combined with tobacco use; the review did not give that study's comparison group
  • The review cited sources stating that household asbestos exposure, as well as occupational exposure, is responsible for thousands of deaths yearly
  • For vaping, the review cited a mouse study in which 9 of 40 mice exposed to e-cigarette fumes for three months developed lung adenocarcinomas. It also cited a study finding that vaporized nicotine was not lung carcinogenic in rats.
  • The authors stated that the relationship between vaping products and lung cancer is not well established
• The authors' conclusion: The authors concluded that chemical groups found in both vaping products and the environment may disrupt lung function and initiate cancer in an additive or synergistic manner, and that more investigation is needed
• Limitations the authors state:
  • The authors stated that published data on heavy metal exposure from e-cigarettes and lung cancer risk are scarce, and that long-term effects may not yet be observable because e-cigarette use is relatively new
  • The authors stated that the precise ways asbestos damages DNA and induces cell death are not well understood
  • The authors stated that the epidemiological evidence linking environmental toxicants and lung cancer is poorly established

Topics

Medical terms in this study, explained in our Lexicon: Lung Cancer, Environmental Exposure, Carcinogenic.

Related studies

• Environmental toxicants--induced epigenetic alterations and their reversers — M. Kim, M. Bae, et al. (2012)
• Role of Macrophages in Acute Lung Injury and Chronic Fibrosis Induced by Pulmonary Toxicants — D.L. Laskin, R. Malaviya, et al. (2019)
• Lung inflammation caused by inhaled toxicants: a review — J. Wong, B.E. Magun, et al. (2016)
• Pulmonary toxicants and fibrosis: innate and adaptive immune mechanisms — R. Malaviya, H.M. Kipen, et al. (2020)
• Biological autoxidation. I. Decontrolled iron: an ultimate carcinogen and toxicant: an hypothesis — S.H. Kon (1978)
• Memory deficits and industrial toxicant exposure: a comparative study of hard metal, solvent and asbestos workers — C.M. Jordan, R.D. Whitman, et al. (1997)

Browse more research in Cancers, or return to medical research.