Does Vaping Cause Lung Cancer? What the Evidence Says

Key Takeaways

• E-cigarette aerosol contains known carcinogens — including formaldehyde, heavy metals, and tobacco-specific nitrosamines — that can damage DNA and promote tumor growth.

• Long-term human data on vaping and lung cancer doesn’t exist yet because e-cigarettes have only been widely used since the late 2000s, and lung cancer typically takes 20–30 years to develop.

• A 2024 study from Ohio State University found that people who both smoke and vape have roughly four times the lung cancer risk of people who only smoke.

• EVALI (e-cigarette or vaping product use-associated lung injury) caused more than 2,800 hospitalizations and 68 deaths in the U.S. in 2019–2020, demonstrating that vaping can produce serious, acute lung harm.

• Every major health organization — including the CDC, FDA, and WHO — agrees that while vaping is likely less harmful than cigarette smoking, it is not safe, and its long-term effects on lung cancer risk remain an active area of concern.

What Vaping Does to Your Lungs

When people talk about vaping, they usually mean using an e-cigarette or similar device that heats a liquid into an aerosol you inhale. That liquid typically contains nicotine, propylene glycol, glycerin, and flavorings — but the aerosol you breathe in is not simply water vapor.

According to the CDC, e-cigarette aerosol can contain a range of harmful and potentially harmful substances. These include:

• Nicotine — highly addictive and harmful to developing brains

• Ultrafine particles that can be inhaled deep into lung tissue

• Volatile organic compounds such as formaldehyde and acetaldehyde, both recognized carcinogens

• Heavy metals including nickel, tin, and lead, which leach from heating coils

• Flavoring chemicals such as diacetyl, linked to a serious lung condition called “popcorn lung” (bronchiolitis obliterans)

The key distinction between vaping and smoking is the absence of combustion. Burning tobacco creates tar and a dense cloud of combustion byproducts — many of them acutely toxic. Vaping avoids that process, which is why most researchers and health agencies consider it likely to be less harmful than smoking. But “less harmful” is not the same as safe. The aerosol still delivers a meaningful dose of lung-damaging chemicals with every puff.

Research published in Tobacco Induced Diseases found that e-cigarette aerosol can trigger oxidative stress, cellular inflammation, and DNA damage — the same biological mechanisms that underpin the development of cancer over time. A single vaping session has been shown in some studies to increase markers of bodily inflammation by roughly 30%.

What the Research Shows on Vaping and Lung Cancer Risk

The honest answer to “does vaping cause lung cancer?” is: we don’t yet know for certain, but the warning signs are real and growing.

E-cigarettes became widely available commercially around 2007. Lung cancer, however, is a slow-developing disease. Most cigarette smokers who develop lung cancer have been smoking for 20 to 30 years or more. That means we are still in the early window for seeing long-term cancer outcomes in people who have vaped since the beginning. Large population cohort studies showing definitive lung cancer rates among vapers simply do not exist yet, not because researchers aren’t looking, but because not enough time has passed.

What the science does show is concerning:

In laboratory settings, e-cigarette aerosol exposure damages DNA in human lung cells and promotes cancer cell growth. Studies have found that vapers carry elevated biomarkers of carcinogens, including formaldehyde, acetaldehyde, acrylamide, toluene, and tobacco-specific nitrosamines, in their urine and breath. Epigenetic research has identified shared DNA methylation changes in both vapers and smokers, including alterations to tumor suppressor genes such as HIC1, which are directly linked to lung cancer development.

In animal studies, mice exposed to e-cigarette aerosol developed lung tumors at higher rates than unexposed controls. These studies provide a plausible biological pathway from vaping to cancer — they don’t confirm it happens in humans at the same rate, but they establish that the mechanism exists.

In human studies, a 2024 study published in PMC and reported by the American Cancer Society found that among former cigarette smokers who had quit for five or more years, those who subsequently used e-cigarettes had a higher risk of both lung cancer incidence and lung cancer-related death than those who did not vape. A systematic review published in ESMO Open in 2025 found no significant incident risk of lung cancer in never-smokers who currently vape, though the authors noted that follow-up periods remain too short to draw firm conclusions.

The biological mechanisms for cancer development — chronic inflammation, DNA damage, oxidative stress — are clearly present with vaping. Whether these lead to lung cancer at population scale, and at what rate, is the central unanswered question.

EVALI: Vaping-Related Lung Injury

While the link between vaping and lung cancer is still being established over decades, there is nothing uncertain about the harm vaping can cause to lungs in the short term.

In 2019 and 2020, the United States experienced a sharp outbreak of a condition now known as EVALI — e-cigarette or vaping product use-associated lung injury. According to the CDC, 2,807 people were hospitalized and 68 people died. Cases peaked in September 2019 and then declined sharply after public health warnings and product reformulations took hold.

The CDC identified vitamin E acetate, a thickening agent added to THC-containing vape cartridges, as the primary chemical responsible. However, it was not the only chemical implicated, and cases occurred among people using nicotine products as well.

It is important to understand that EVALI is not lung cancer. EVALI is an acute inflammatory injury of the lung that causes fever, cough, shortness of breath, and in severe cases, respiratory failure requiring hospitalization within days or weeks of exposure. Lung cancer, by contrast, develops over many years through cellular mutation and tumor growth.

What EVALI makes clear is that vaping can cause serious, life-threatening damage to your lungs and that products sold informally, without regulatory oversight, carry the highest risk. Cases of EVALI have continued to be reported by clinicians even after CDC tracking ceased in early 2020.

Vaping vs. Smoking: Which Is Worse for Lung Cancer Risk?

Cigarette smoking is one of the most thoroughly studied causes of lung cancer in human history. It is responsible for roughly 80–85% of all lung cancer cases in the United States. There is no ambiguity: smoking causes lung cancer.

Vaping, by most accounts, is likely less harmful than smoking for lung cancer risk — for now and based on current evidence. The absence of combustion means vapers are not exposed to tar or the full spectrum of combustion byproducts that make cigarette smoke so acutely carcinogenic. Carcinogen levels in e-cigarette aerosol are generally lower than in tobacco smoke.

But this comparison has important limits:

Dual use is particularly dangerous. Many people who vape also continue to smoke — this is the worst-case scenario. A landmark 2024 study from the Ohio State University Comprehensive Cancer Center analyzed data from 4,975 lung cancer cases and 27,294 controls. People who both smoked and vaped had approximately four times the lung cancer risk of people who only smoked — with an adjusted odds ratio of 38.7 compared to 9.6 for smoking alone. The researchers described the finding as striking. If you smoke and vape, quitting both matters enormously.

Vaping is a new risk for people who have never smoked. Young people who have never smoked cigarettes and who take up vaping are not choosing a safer alternative to smoking — they are adding a new risk. For never-smokers, any level of carcinogen exposure in the lungs represents a step in the wrong direction.

We don’t have 30-year data yet. Comparative safety today is not the same as confirmed safety over a lifetime.

Who Is Most at Risk From Vaping?

While vaping affects anyone who does it, some groups face compounded risks:

Young people and adolescents. The lungs continue developing into a person’s mid-20s. Exposure to carcinogens, nicotine, and inflammatory agents during this developmental window may carry greater long-term consequences. The Surgeon General has called youth vaping a public health epidemic.

Former smokers who haven’t fully quit. If you smoked for years before switching to vaping, your lungs may already carry pre-existing damage, like inflamed tissue, DNA alterations, and compromised repair mechanisms. Adding vaping to that history compounds the risk rather than erasing it. Research presented at the 2024 American Thoracic Society International Conference was the first large population-based study to demonstrate elevated lung cancer risk among e-cigarette users after smoking cessation.

Dual users. People who vape and smoke simultaneously face the sharpest measured increase in lung cancer risk identified in human research to date.

People using THC vape cartridges from informal  or unregulated sources. These products are less regulated, more likely to contain additives like vitamin E acetate, and were the primary driver of the EVALI outbreak. The risk profile for informally sourced THC cartridges is meaningfully higher than for regulated nicotine products. For more on this topic, see our article on weed and lung cancer.

What Major Health Organizations Say

The leading health and medical authorities have reached a consistent position: vaping is harmful to lung health, and while it may be less harmful than cigarette smoking, it is not safe.

• The CDC states that e-cigarette aerosol contains harmful and potentially harmful substances including cancer-causing chemicals, and that scientists still have much to learn about the long-term health effects of e-cigarette use.

• The FDA has not approved any e-cigarette as safe or effective for helping people quit smoking, and has stated that no e-cigarette has been found to be safe and effective.

• The WHO recommends against the use of e-cigarettes and has called for stronger regulatory action to protect young people from initiation.

• The NCI notes that e-cigarettes deliver nicotine along with other harmful chemicals, and that evidence on long-term cancer risk is still emerging.

• The American Lung Association warns that e-cigarettes are not a safe alternative to smoking and that inhaling the aerosol causes lung inflammation and can cause lasting damage.

• The Surgeon General has called e-cigarette use among youth a public health epidemic and has warned that nicotine exposure during adolescence harms the developing brain and lungs.

The consensus is not that vaping is harmless — it is that we are still measuring exactly how harmful it will prove to be over time.

If You Vape: Steps to Reduce Risk

Quitting vaping is the most effective step you can take to reduce your risk. Here is what that looks like in practice:

Talk to your doctor. Nicotine replacement therapies (patches, gum, lozenges), prescription medications such as varenicline, and behavioral counseling have all shown effectiveness for quitting nicotine products,  including e-cigarettes. A combination approach works better than any single method alone.

Don’t switch back to cigarettes. If you’re quitting vaping, returning to smoking is not the answer. Cigarettes carry far greater documented harm. Work with a healthcare provider on a path that doesn’t involve combustible tobacco.

Use the quitline. The national tobacco quitline (1-800-QUIT-NOW) and online resources such as smokefree.gov offer free support, coaching, and personalized quitting plans.

Avoid THC cartridges from unregulated sources. If you choose to use cannabis, be aware that vape cartridges purchased outside of licensed dispensaries carry significant additional risks, including the chemicals linked to EVALI.

Watch for symptoms. Cough that doesn’t resolve, shortness of breath, chest pain, coughing up blood, and unexplained weight loss all warrant medical evaluation, especially if you vape or have a history of smoking. These are known lung cancer symptoms. Early detection dramatically improves outcomes, so don’t wait.

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Frequently Asked Questions

Does vaping cause lung cancer?

There is not yet conclusive evidence from long-term human studies that vaping directly causes lung cancer — primarily because e-cigarettes have only been widely available since around 2007, and lung cancer typically takes 20–30 years to develop. However, laboratory and animal studies confirm that e-cigarette aerosol can damage DNA, cause oxidative stress, and promote tumor growth. Human studies are beginning to show elevated cancer risk, particularly among dual users (people who both smoke and vape). Most health experts expect that long-term vaping will prove harmful to lung cancer risk — the science simply hasn’t had enough time to catch up yet.

Is vaping safer than smoking cigarettes for lung cancer risk?

Based on current evidence, vaping is likely less harmful than smoking cigarettes in terms of lung cancer risk — primarily because e-cigarettes don’t involve combustion, which eliminates tar and many of the most acutely carcinogenic byproducts of burning tobacco. However, “safer than smoking” is not the same as safe. Vaping still delivers carcinogens and causes lung inflammation. For people who have never smoked, vaping represents an added cancer risk, not a neutral choice. For people who both smoke and vape, a 2024 Ohio State University study found the risk to be roughly four times higher than smoking alone.

What is EVALI, and is it the same as lung cancer?

EVALI (e-cigarette or vaping product use-associated lung injury) is an acute inflammatory injury of the lungs caused by inhaling certain chemicals in vape products — most prominently vitamin E acetate found in THC cartridges. It is not the same as lung cancer. EVALI develops rapidly, causing severe respiratory symptoms within days to weeks, while lung cancer develops over many years through cellular mutation. The 2019–2020 EVALI outbreak in the U.S. resulted in 2,807 hospitalizations and 68 deaths. EVALI demonstrates that vaping can cause severe, acute lung harm — separate from and in addition to any long-term cancer risk.

If I quit vaping, does my lung cancer risk go down?

Yes — quitting any tobacco or nicotine product reduces your long-term cancer risk, and the sooner you quit, the greater the benefit. After you stop vaping, your lungs begin to clear inflammatory cells, oxidative stress markers decrease, and your body’s DNA repair mechanisms have a better chance to correct accumulated damage. The risk reduction from quitting vaping is not yet quantified with the same precision as for cigarette cessation (where we have decades of data), but the biological rationale is clear: removing the source of lung damage and carcinogen exposure gives your body the opportunity to recover.

References

1. Centers for Disease Control and Prevention. (2024). Health effects of vaping. https://www.cdc.gov/tobacco/e-cigarettes/health-effects.html

2. Wills, T. A., et al. (2024). Vaping, smoking and lung cancer risk. PMC. https://pmc.ncbi.nlm.nih.gov/articles/PMC11361252/

3. Ohio State University Comprehensive Cancer Center. (2024). Vaping and smoking together increases lung cancer risk fourfold. https://cancer.osu.edu/news/vaping-and-smoking-together-increases-lung-cancer-risk-fourfold

4. Tsai, M., et al. (2025). The risk of lung cancer from vaping or e-cigarette usage: a systematic review. ESMO Open. https://pmc.ncbi.nlm.nih.gov/articles/PMC12670536/

5. Centers for Disease Control and Prevention. (2020). Update: Characteristics of a nationwide outbreak of e-cigarette, or vaping, product use-associated lung injury — United States, August 2019–January 2020. MMWR. https://www.cdc.gov/mmwr/volumes/69/wr/mm6903e2.htm

6. Mravec, B., et al. (2022). Can electronic-cigarette vaping cause cancer? PMC. https://pmc.ncbi.nlm.nih.gov/articles/PMC9222281/

7. American Thoracic Society. (2024). Ex-cigarette smokers who vape may be at higher risk for lung cancer. https://site.thoracic.org/about-us/news/2024-international-conference-press-release/ex-cigarette-smokers-who-vape-may-be-at-higher-risk-for-lung-cancer

8. Goniewicz, M. L., et al. (2024). Evidence update on the cancer risk of vaping e-cigarettes: A systematic review. Tobacco Induced Diseases. https://www.tobaccoinduceddiseases.org/Evidence-update-on-the-cancer-risk-of-vaping-e-cigarettes-A-systematic-review,192934,0,2.html