Is Vaping Safer than Smoking Cigarettes?

Laura Gottschalk, PhD, John-Anthony Fraga, Jared Hirschfield, Diana Zuckerman, PhD, National Center for Health Research

Electronic Cigarette SmokingElectronic cigarettes, or e-cigarettes, are being marketed as the “safe” new alternative to conventional cigarettes. By February 2020, reports of 68 deaths and more than 2,800 vaping-related hospitalizations due to lung illnesses have made it clear that vaping can be even more dangerous than smoking.1,2 On June 23, 2022 the FDA ordered Juul to stop selling their e-cigarettes in the US, citing concerns about the company’s “insufficient and conflicting data” on toxicity.3  Although the FDA did not express concerns about an immediate hazard, they were concerned about the longer term safety from the use of JUUL devices or pods, raising questions about whether the possible benefits of reducing smoking outweigh the risks from these products.

The CDC has reported that Vitamin E acetate is a potential cause for the outbreak, but it might not be the only one. Many of the patients report vaping marijuana products or marijuana and nicotine products, but others only vaped nicotine products. Until these reports of hospitalized teens and adults are scrutinized in greater depth, we won’t know what types of vaping are most dangerous and under what circumstances.

E-cigarettes come in a variety of forms and include vape mods, Juuls, and vape pens. There are brand name products (Juul is the most widely used) and “home-made” versions. Some contain high levels of nicotine, while others contain marijuana or flavoring. In 2016, the FDA’s Center for Tobacco Prevention (CTP) started regulating e-cigarettes because their nicotine content is similar to that of traditional cigarettes and other tobacco products. So although e-cigarettes often do not contain tobacco and do not always contain nicotine, CTP regulates e-cigarettes with cigarettes and other nicotine sources. The focus of this article is on e-cigarettes because most of the research that exists has been done on them, but much of the information below is relevant to other vaping products as well.

The big questions are: Are they safe?  Will they reverse the decline in smoking—giving new life to an old habit—or can they help people quit smoking?  Here is what you need to know.

What are E-cigarettes?

E-cigarettes are battery-operated devices that were initially shaped like cigarettes, but now include vape mods, Juuls, and vape pens. Some look like flash drives or highlighter pens, making it easy for teens to hide them in plain sight.  The brand-name products contain nicotine, an addictive drug that is naturally found in tobacco and that stimulates, causes stress during withdrawal, and then feels relaxing as continued exposure follows withdrawal. It is the nicotine in cigarettes that makes smoking so addictive, and the same is true for most vaping and juuling. These electronic products allow nicotine to be inhaled, and they work by heating a liquid cartridge containing nicotine, flavors, and other chemicals into a vapor. Because e-cigarettes heat a liquid instead of tobacco, what is released is considered smokeless and what small amount of smoke is produced is often odorless.4

Which is Safer: Vaping or Traditional Cigarettes?

While smoking can cause lung cancer, breast cancer, emphysema, heart disease, and other serious diseases, those diseases usually develop after decades of smoking. In contrast, in 2019 it became clear that vaping could cause seizures and serious lung damage after just a year, possibly less, based on CDC reports of patients hospitalized for lung damage caused by vaping.2,4 While there have been warnings about the possible risk of e-cigarettes for a decade, it was not expected that they could cause such severe damage in such a short period of time.  This article will focus on what we know and don’t know about the safety of vaping compared to smoking.

The key difference between traditional cigarettes and e-cigarettes and related products is that the latter don’t contain tobacco. But, it isn’t just the tobacco in cigarettes that causes cancer and other serious diseases. Traditional cigarettes contain a laundry list of chemicals that are proven harmful, and e-cigarettes have some of these same chemicals.

As of February 18, 2020, over 2,800 hospitalizations with 68 fatal cases of vaping related injuries were reported to the CDC. The long term effects of vaping are still being studied, but this shows the seriousness of vaping related injuries in just a few years. Unfortunately, as of July 2023, there have not been any updates of vaping-related hospitalizations or deaths from CDC since 2020, probably because of the pandemic. We will update the data when it becomes available. An update is urgently needed because vaping has become more popular since 2020.5

Since 2009, FDA has pointed out that e-cigarettes contain “detectable levels of known carcinogens and toxic chemicals to which users could be exposed.” For example, in e-cigarette cartridges marketed as “tobacco-free,” the FDA detected a toxic compound that’s also found in antifreeze and other tobacco-specific compounds that have been shown to cause cancer in humans, and other toxic tobacco-specific impurities.7 Another study looked at 42 of these liquid cartridges and determined that all contained detectable levels of formaldehyde, a chemical known to cause cancer in humans.8 Formaldehyde levels in several of the cartridges were much higher than the maximum EPA recommends for humans. In 2017, a study published in the Public Library of Science Journal showed that significant levels of benzene, a well-known carcinogen, were found in the vapor produced by several popular brands of e-cigarettes.9

The body’s reaction to many of the chemicals in traditional cigarette smoke causes long-lasting inflammation, which in turn leads to chronic diseases like bronchitis, emphysema, and heart disease.10 Since e-cigarettes also contain many of the same toxic chemicals, there is no reason to believe that they will significantly reduce the risks for these diseases. A study published in the Journal of the American Medical Association (JAMA) in 2023 raised concerns that vaping might be associated with increased risk of stroke. 11 The authors called for a well-designed study to be conducted looking at this relationship because their research indicated that vaping can lead to increased heart rate, blood pressure, and blood platelet aggregation, all of which are linked to strokes. 

Some e-cigarette users also smoke marijuana and/or conventional cigarettes, and it is important to know if e-cigarette use alone can lead to breathing problems, independently of other types of smoking. A survey of almost 3,000 teens and young adults found that even when statistically controlling for whether they also smoking marijuana or conventional cigarettes, those who reported e-cigarette use in the last 30 days were statistically significantly more likely than non e-cigarette users to report problems with wheezing and shortness of breath.6

There is preliminary evidence that vaping can harm DNA.  A study presented at the 2018 annual meeting of the American Chemical Society examined the saliva of 5 adults before and after a 15-minute vaping session. The saliva had an increase in potentially dangerous chemicals, such as formaldehyde and acrolein.12 Acrolein has been proven to be associated with DNA damage, and DNA damage can eventually cause cancer.13   In addition, a study of mice funded by the National Institutes of Health found that e-cigarette smoke could cause mutations in DNA that could increase the risk of cancer. These specific mutations have been shown to potentially contribute to the development of lung and bladder cancer in mice exposed to electronic cigarette smoke. The researchers claim that these chemicals could also induce mutations leading to cancer in humans. However, studies looking at the potentially cancerous effects in humans may take decades to publish because it takes that long for cancer to develop in our bodies. 

Although the COVID-19 pandemic knocked vaping concerns off the headlines, the pandemic raised even more concerns about the safety of vaping. Youths aged 13-24 years old who have used e-cigarettes were more likely to be diagnosed with COVID-19, be tested for the virus, and to experience COVID-19 symptoms.6

Can Vaping Help to Cut Down or Quit Smoking Regular Cigarettes?

If a company makes a claim that its product can be used to treat a disease or addiction, like nicotine addiction, it must provide studies to the FDA showing that its product is safe and effective for that use. On the basis of those studies, the FDA approves or doesn’t approve the product. So far, there are no large, high-quality studies looking at whether e-cigarettes can be used to cut down or quit smoking long-term. Most of the studies have been either very short term (6 months or less) or the participants were not randomly assigned to different methods to quit smoking, including e-cigarettes. Many of the studies are based on self-reported use of e-cigarettes. For example, a study done in four countries found that e-cigarette users were not more likely to quit than regular smokers even though 85% of them said they were using them to quit.16 Year-long studies conducted in the U.S. had similar findings.  A study published in a prestigious medical journal in 2014 found that although smokers may believe they are vaping e-cigarettes to help them quit,  6-12 months after being first interviewed, nearly all of them are still smoking regular cigarettes.16 Similarly, a year-long study published in 2018 compared smokers who used e-cigarettes to traditional cigarette smokers. They concluded that e-cigarette users were more likely to say they were trying to quit but no more likely to successfully kick the smoking habit, with 90% of e-cigarette users still smoking regular cigarettes at the end of the study.  Until there are results from well-conducted studies, the FDA will not approve e-cigarettes for use in quitting smoking.17

Teenagers, Children, and Vaping

Since 2014, e-cigarettes have been the most commonly used tobacco product among teens. In 2019,20 about 28% of high schoolers and 11% of middle schoolers reported e-cigarette use, with most using flavored products.21 A later analysis of these same data provided more in depth numbers looking at racial differences in e-cigarette use. They found that 36% of white teens, 14% of black teens, 21% of hispanic teens, and 28% of teens classified as other reported to frequently use vapes (meaning they vaped 20 or more days in the previous 30 days).22 Also in 2019, researchers from the University of Michigan studied more than 8,000 students in the 10th and 12th grades nationwide and found that 22% reported vaping in the last 30 days.23 And a CDC study from 2020 analyzed data from over 14,000 students nationwide, found that about 20% of 9th-12th grade students and 5% of 6th-8th grade students reported that they used e-cigarettes in the last 30 days.23 However, 2022 CDC data show that vaping use has dropped, with 14% of high schoolers and 3% of middle schoolers reporting current e-cigarette use.24 E-cigarette use may have dropped due to growing media coverage of young men hospitalized with serious lung damage23,25 or due to raising the legal age for the purchase of tobacco products and the ban on many flavored products.23,25 

An online survey conducted in May 2020 measured how e-cigarette use changed during the pandemic, during a time where many people are staying at home.25 The survey included almost 1,500 participants under 21 (the legal age to purchase tobacco products) who reported e-cigarette use. Over half of the underage e-cigarette users who responded to the survey reported that they had changed their e-cigarette use during the pandemic. About 20% of the sample had quit using e-cigarettes altogether, about 17% reduced their use slightly or by half, and another 9% actually increased their nicotine use. 

The researchers followed up by asking those participants who reduced their e-cigarette use for the reasons why they lowered it. About 14% reported that the primary reason for reducing was because they were at home and their parents would know, 18% said the primary reason was because they can no longer get the tobacco products, 23% said it was because they know e-cigarette use harms the lungs, and another 37% said that their reasons were a combination of those 3 reasons. Of those who increased their use during the pandemic, about 25% reported that it was due to boredom, 15% because they were stressed, 7% because they needed a distraction, and about 50% said that their reasons were a combination of those 3 reasons. New research is needed to measure whether e-cigarette use has changed since the pandemic.   

E-cigarette use by young people is worrisome for several reasons:   

  1.   The younger people are when they begin smoking, the more likely it is they will develop the habit: nearly 9 out of 10 smokers started before they were 18.26
  2.   Nicotine and other chemicals found in e-cigarettes, juuls, etc. might harm brain development in younger people.27
  3.   Vaping may introduce many more young people to smoking who might otherwise never have tried it, and once they are addicted to nicotine, some may decide to get their “fix” from regular cigarettes. Whether vaping or juuling is a “gateway” to regular cigarettes or not, young people who use them risk becoming addicted to nicotine and exposing their lungs to harmful chemicals.
  4.   While smoking can cause permanent lung damage over the years, vaping can cause inflammation resulting in hospitalization and permanent damage after just a few weeks or months.28,29

The sharp rise in vaping among youth highlights the need to stop manufacturers from targeting teenagers with candy-like flavors and advertising campaigns. Although the FDA banned flavors for reusable vape devices, flavored disposable e-cigarettes are still being sold.20 

Even children who are too young to smoke have been harmed by e-cigarettes and related products. The liquid is highly concentrated, so absorbing it through the skin or swallowing it is far more likely to require an emergency room visit than eating or swallowing regular cigarettes. In 2012, fewer than 50 kids under the age of six were reported to poison control hotlines per month because of e-cigarettes. In 2015, that number had skyrocketed to about 200 children a month, almost half of which were under the age of two.31  According to the CDC, between April 1, 2022 and March 31, 2023 over 7,000 cases were reported (an average of 590 a month)!32 This number is considered to be underreported since most cases aren’t reported to Poison Control. These numbers may continue to increase as more e-cigarettes and e-liquid are being sold across the country.

Many e-cigarettes look like USB devices, and some are made to look like other products, in order to disguise their use. The Director of Communications at the FDA’s Center for Tobacco Products has written this guide to help parents identify these hidden e-cigarettes. The FDA has also helped create this pamphlet for parents and teens to discuss the risks of vaping, and it provides resources for saying “no” and for quitting.

For more information about juuls, check out our article here.

If They Aren’t Safe, Why Can They Be Sold in the U.S.?

The FDA was given the power to regulate the manufacturing, labeling, distribution and marketing of all tobacco products in 2009 when President Obama signed into law the Family Smoking Prevention and Tobacco Control Act and in 2010 a court ruled that the FDA could regulate e-cigarettes as tobacco products.32

E-Cigarette Ad

However, it wasn’t until 2016 that the FDA finalized a rule to ban the sale of e-cigarettes to anyone under the age of 18 and to require all e-cigarettes that hit shelves after February 15, 2007 to go through a “premarket review,” the process that the FDA uses to determine whether a medical product is safe.26 Companies were to be given from 18-24 months to prepare their applications. However, in 2017, the Trump administration appointed a new FDA Commissioner, Dr. Scott Gottlieb, who defended the safety of e-cigarettes and delayed implementing the rules until 2022.11 In 2018, as the epidemic of e-cigarette use among youth became obvious, Commissioner Gottlieb threatened to crack down on the advertising of e-cigarettes to children under 18,33 although online sales and ads are difficult to restrict. Commissioner Gottlieb resigned in 2019, and that same year a federal court ruled that the FDA must implement regulations in May 2020 instead of waiting until 2022. 

In September 2019, President Trump proposed a ban on all flavored e-cigarettes.  No action was taken until January 2020, when Trump weakened his proposal so that it did not include a ban on menthol or tobacco flavored e-cigarettes or on large tank-style e-cigarettes. However, in July 2020, FDA issued warnings to 10 companies selling flavored disposable e-cigarettes, notifying them to remove their products from the market because they did not have the authorizations required to sell them.30

A federal court order required vape and e-cigarette companies to submit marketing applications to the FDA by September 2020, and their products were allowed to stay on the market for up to 1 year while the FDA reviewed their applications.33  The Biden Administration took quick action starting in January 2021, and for the first 8 months of that year the FDA issued 169 warning letters to firms who manufacture and sell unauthorized e-cigarettes and vaping products with nicotine, advising them that it is illegal to sell their products because the companies did not submit an application to do so by the Sept. 9, 2020 deadline. During that year, the FDA rejected the applications for more than 1 million flavored vape products.35  In August 2021, FDA warned two companies that had submitted applications by September 9, 2020 that had not met FDA standards, and one company that submitted an application for some but not all of their products, to stop selling the products that were not authorized to be sold. In October 2021, the FDA authorized the marketing of three vaping products (Vuse Solo products), but rejected flavored vaping products other than tobacco flavor. In July 2022, FDA announced they were banning Juul products stating there wasn’t enough evidence for a full ‘toxicological profile.’ However, Juul appealed this decision and are still able to sell unflavored products until the final ruling on their products.36  FDA Warnings continued and in November 2022 FDA issued 440 warnings for e-cigarettes that look like toys, 30 letters for unauthorized selling of disposable e-cigarettes in May 2023, and 180 additional letters for the illegal sale of youth-appealing vapes in June 2023.

The Bottom Line

E-cigarettes, juul, and other similar products have not been around long enough to conclusively determine the harm they cause in the long run. Unfortunately, many people, including teenagers, are under the impression that e-cigarettes are safe. Studies by the FDA show that e-cigarettes contain some of the same toxic chemicals as regular cigarettes, even though they don’t have tobacco. There is evidence that some of these toxic chemicals can cause DNA damage that can cause cancer. More importantly, the reports of teens and adults who died or were hospitalized due to vaping are proof that vaping can be extremely dangerous even after just a few weeks, months, or years.

The big three tobacco companies—Lorillard, Reynolds American, and Altria Group—all have their own e-cigarette brands, so it’s not surprising that e-cigarettes are being marketed and advertised much the way regular cigarettes used to be. Here are the 7 Ways E-Cigarette Companies Are Copying Big Tobacco’s Playbook.

Although there are clearly serious dangers from vaping, more research is needed to confirm the impact of vaping on DNA damage, especially in children. Meanwhile, claims that e-cigarettes are an effective strategy to quit smoking are not supported by the evidence. More toxicological studies and epidemiological studies are needed to understand the hundreds of reports of permanent lung damage and deaths from vaping, and to find out whether some types of vaping are more dangerous than others in the short-term and the long-term. To understand the risks for everyone who vapes, research is needed to compare the risks of specific brands of e-cigarettes with tobacco products, as well as to neither smoking nor vaping.

All articles are reviewed and approved by Dr. Diana Zuckerman and other senior staff.

The National Center for Health Research is a nonprofit, nonpartisan research, education and advocacy organization that analyzes and explains the latest medical research and speaks out on policies and programs. We do not accept funding from pharmaceutical companies or medical device manufacturers. Find out how you can support us here.

    1. Robert Langreth. More Evidence Links Vaping Lung Injuries to Vitamin E Acetate. December 20, 2019.
      https://www.bloomberg.com/news/articles/2019-12-20/more-evidence-links-vaping-lung-injuries-to-vitamin-e-acetate 
    2. Centers for Disease Control and Prevention. Outbreak of Lung Injury Associated with the Use of E-Cigarette, or Vaping, Products. Updated 2020. https://www.cdc.gov/tobacco/basic_information/e-cigarettes/severe-lung-disease.html
    3. FDA Denies Authorization to Market JUUL Products. 2022. FDA. https://www.fda.gov/news-events/press-announcements/fda-denies-authorization-market-juul-products. Accessed June 23, 2022.
    4. O’Connor RJ. Non-cigarette tobacco products: What have we learned and where are we headed? Tobacco Control. 2012;21(2): 181–190. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3716250/
    5. Jonas A. (2022). Impact of vaping on respiratory health. BMJ (Clinical research ed.), 378, e065997. https://doi.org/10.1136/bmj-2021-065997
    6. Boyles S. Vaping Alone May Boost Lung Troubles. MedPageToday. https://www.medpagetoday.com/meetingcoverage/ats/92663. May 18, 2021.
    7. Gaiha SM, Cheng J, Halpern-Felsher B. Association between youth smoking, electronic cigarette use, and COVID-19. Journal of Adolescent Health. 2020;67(4):519-523. doi:10.1016/j.jadohealth.2020.07.002
    8. Food and Drug Administration. Summary of Results: Laboratory analysis of electronic cigarettes conducted By FDA. FDA News & Events. July 22 2009.
    9. Varlet V,  Farsalinos K, Augsburger M, et al. Toxicity of refill liquids for electronic cigarettes. International Journal for Environmental Research and Public Health. 2015;12:4796-4815. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4454939/
    10. Pankow JF, Kim K, McWhirter KJ, et al. Benzene formation in electronic cigarettes. PLOS ONE. 2017;12(3),e0173055. https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/28273096/
    11. Elser, H., Vijayaraghavan, M., & Kasner, S. E. (2023). E-Cigarettes and Stroke Risk-Present Uncertainties and Future Directions. JAMA neurology, 10.1001/jamaneurol.2023.2050. Advance online publication. https://doi.org/10.1001/jamaneurol.2023.2050
    12. Centers for Disease Control and Prevention. Overviews of Diseases/Conditions. February 2019.  https://www.cdc.gov/tobacco/campaign/tips/diseases/index.html
    13. McGinley, L. FDA sued for delaying e-cigarette, cigar regulations. Washington Post. March 27 2018.  https://www.washingtonpost.com/news/to-your-health/wp/2018/03/27/fda-sued-for-delaying-e-cigarette-cigar-regulations/?utm_term=.f92695720619.
    14. Lee HW, Park SH, Weng MW, et al. E-cigarette smoke damages DNA and reduces repair activity in mouse lung, heart, and bladder as well as in human lung and bladder cells. Proceedings of the National Academy of Sciences of the United States of America. 2018;115(7), E1569. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5816191/
    15. Kaisar MA, Prasad S, Liles T, et al. A decade of e-cigarettes: Limited research & unresolved safety concerns. Toxicology. 2016;365: 67–75. http://doi.org/10.1016/j.tox.2016.07.020
    16. Robert Langreth. More Evidence Links Vaping Lung Injuries to Vitamin E Acetate. December 20, 2019.
      https://www.bloomberg.com/news/articles/2019-12-20/more-evidence-links-vaping-lung-injuries-to-vitamin-e-acetate  
    17. Kaplan S. E-Cigarette exploded in a teenager’s mouth, damaging his jaw.  The New York Times. June 19 2019.  https://www.nytimes.com/2019/06/19/health/ecigarettes-explosion.html
    18. Adkison SE, O’Connor RJ, Bansal-Travers M, et al. Electronic nicotine delivery systems: International tobacco control four-country survey. American Journal of Preventive Medicine. 2013;44(3):207-215. https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/23415116/
    19. Grana RA, Popova L, Ling PM. A longitudinal analysis of electronic cigarette use and smoking cessation. JAMA Internal Medicine. 2014;174(5):812–813. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4122246/
    20. Food and Drug Administration. Electronic Cigarettes. FDA News & Events. 25 July 2013.
    21. Odani S, Armour BS, Agaku IT. Racial/ethnic disparities in tobacco product use among middle and high school students—United States, 2014–2017. Morbidity and Mortality Weekly Report. 2018 Aug 31;67(34):952.
    22. Dai, H., Ramos, A. K., Faseru, B., Hill, J. L., & Sussman, S. Y. (2021). Racial Disparities of E-Cigarette Use Among US Youths: 2014‒2019. American journal of public health, 111(11), 2050–2058. https://doi.org/10.2105/AJPH.2021.306448
    23. Cullen KA, Gentzke AS, Sawdey MD, Chang JT, Anic GM, Wang TW, Creamer MR, Jamal A, Ambrose BK, King BA. E-cigarette use among youth in the United States, 2019. JAMA. 2019 Dec 3;322(21):2095-103.
    24. Cooper, M., Park-Lee, E., Ren, C., Cornelius, M., Jamal, A., & Cullen, K. A. (2022). Notes from the Field: E-cigarette Use Among Middle and High School Students – United States, 2022. MMWR. Morbidity and mortality weekly report, 71(40), 1283–1285. https://doi.org/10.15585/mmwr.mm7140a3
    25. Gentzke AS, Wang TW, Jamal A, et al. Tobacco Product Use Among Middle and High School Students — United States, 2020. MMWR Morb Mortal Wkly Rep 2020;69:1881–1888. DOI: http://dx.doi.org/10.15585/mmwr.mm6950a1external icon.
    26. Miech R, Leventhal A, Johnston L, O’Malley PM, Patrick ME, Barrington-Trimis J. Trends in Use and Perceptions of Nicotine Vaping Among US Youth From 2017 to 2020. JAMA Pediatrics. Published online December 15, 2020. doi:10.1001/jamapediatrics.2020.5667
    27. Grady D. A Young Man Nearly Lost His Life to Vaping. The New York Times. October 15, 2019. https://www.nytimes.com/2019/10/15/health/vaping-thc-illness.html  
    28. Stobbe S, Perrone M. Big drop reported in vaping by US teenagers. Associated Press. September 9, 2020. https://apnews.com/c5524d4c1e7f9148c3293cc3677c0fe5 
    29. Gaiha SM, Lempert LK, Halpern-Felsher B. Underage Youth and Young Adult e-Cigarette Use and Access Before and During the Coronavirus Disease 2019 Pandemic. JAMA Network Open. 2020 Dec 1;3(12):e2027572-.
    30. Centers for Disease Control and Prevention. Fact sheets: Youth and tobacco use. Updated 2019. http://www.cdc.gov/tobacco/data_statistics/fact_sheets/youth_data/tobacco_use/
    31. Centers for Disease Control and Prevention. Preventing tobacco use among youth and young adults. 2012. http://www.cdc.gov/tobacco/data_statistics/sgr/2012/index.htm
    32. Tashakkori NA, Rostron BL, Christensen CH, Cullen KA. Notes from the Field: E-Cigarette–Associated Cases Reported to Poison Centers — United States, April 1, 2022–March 31, 2023. MMWR Morb Mortal Wkly Rep 2023;72:694–695. DOI: http://dx.doi.org/10.15585/mmwr.mm7225a5.
    33. Scutti S. Teen develops ‘wet lung’ after vaping for just 3 weeks. CNN. May 18, 2018. https://www.cnn.com/2018/05/17/health/case-study-teen-vaping-wet-lung/index.html
    34. Song MA, Reisinger SA, Freudenheim JL, Brasky TM, Mathé EA, McElroy JP, Nickerson QA, Weng DY, Wewers MD, Shields PG. Effects of electronic cigarette constituents on the human lung: A pilot clinical trial. Cancer Prevention Research. 2020 Feb 1;13(2):145-52.
    35. U.S. Food and Drug Administration. FDA Notifies Companies, Including Puff Bar, to Remove Flavored Disposable E-Cigarettes and Youth-Appealing E-Liquids from Market for Not Having Required Authorization. Updated July 2020. https://www.fda.gov/news-events/press-announcements/fda-notifies-companies-including-puff-bar-remove-flavored-disposable-e-cigarettes-and-youth 
    36. Hassan, C., Howard, J., & Christensen, J. (2022, June 24). FDA orders Juul Labs to remove products from US market. CNN. https://www.cnn.com/2022/06/23/health/juul-taken-off-market-fda/index.html
    37. Kamboj A, Spiller HA, Casavant MJ, et al. Pediatric exposure to e-cigarettes, nicotine, and tobacco products in the United States. Pediatrics. 2016;137(6). pii: e20160041. https://pediatrics.aappublications.org/content/137/6/e20160041.long
    38. Food and Drug Administration. Regulation of E-Cigarettes and Other Tobacco Products. FDA News & Events. April 25, 2011.
    39. Saltzman J, Freyer F. The FDA issues a warning: Teen vaping is ‘an epidemic.’ Boston Globe. September 13 2018. https://www.bostonglobe.com/metro/2018/09/12/fda-cracks-down-vaping-orders-makers-address-sales-minors/JaiqQYzZAl4CINLufnkKlL/story.html
    40. Food and Drug Administration. FDA Permits Marketing of E-Cigarette Products, Marking First Authorization of Its Kind by the Agency. October 12, 2021. https://www.fda.gov/news-events/press-announcements/fda-permits-marketing-e-cigarette-products-marking-first-authorization-its-kind-agency 
    41. Campaign for Tobacco-Free Kids. New Report: E-Cigarettes in Kid-Friendly Flavors Remain Widely Available Three Months After Deadline for FDA Action. Press Release. December 17, 2021. https://www.tobaccofreekids.org/press-releases/2021_12_17_flavor-report?