Q&A: What does the science REALLY say about vaping? We ask an expert.

Ali Anderson

May 29, 2025

Q&A: What does the science REALLY say about vaping? We ask an expert.

In the debate over vaping, misinformation often clouds the facts - leaving the public confused and policymakers uncertain. 

To cut through the noise, we turned to one of the world's leading voices on tobacco harm reduction: Clive Bates. 

A former director of the charity Action on Smoking and Health UK and long-time advocate for evidence-based public health policy, Bates has spent decades analysing the science and policy around tobacco and nicotine. 

1. Is vaping just as harmful as smoking?

No. Vaping poses only a small fraction of the risk of smoking. We know this with confidence because of the far lower toxicity of vape aerosol compared to cigarette smoke and measurements of exposure to toxicants in the blood, saliva and urine of human users (so-called biomarkers of exposure), which come out comparable to people who have quit smoking completely.   

2. Does vaping cause “popcorn lung” or other serious lung diseases?

Despite repeated claims, there is no evidence that vaping causes popcorn lung. The Health Security Agency in the UK describes this as a "myth". The ingredient that is supposed to cause popcorn lung, diacetyl, is present at levels far below those found in cigarettes, and popcorn lung is not evident in people who smoke cigarettes.  

Diacetyl is banned in the UK and should be banned in every European Union member state under the terms of the Tobacco Products Directive. There were claims in 2019-20 that vaping caused an outbreak of serious lung injuries ("EVALI"), resulting in over 2,800 hospitalisations and 68 deaths in the United States. These were caused by adulterated cannabis vapes, and nicotine vaping was not and could not have been implicated. 

3. Are the chemicals in e-liquids worse than what’s in cigarettes? 

No. There are thousands of chemicals formed in uncontrolled combustion processes at high temperatures in the burning tip of a cigarette. These include toxic agents causing cancer and cardiovascular disease and contributing to progressive respiratory conditions like COPD. Most of the hazardous agents in cigarette smoke are either not present at detectable levels or present at much lower levels.

4. What does the science say about vaping as a quit-smoking tool? 

Several different forms of science triangulate to show that vaping displaces smoking and helps people who smoke to quit. We have good evidence from randomised controlled trials, population trends, economic studies and extensive user testimony that vaping displaces smoking.  

But vaping is more than just a fancy smoking cessation aid. It may reach people who never intended to quit smoking and may divert young people who would otherwise have smoked. Vaping is best understood as a consumer rival to smoking, meeting the demand for nicotine at far lower risk, even though it can be used in a more clinical setting as a kind of advanced nicotine replacement therapy. 

5. Is the rise in youth vaping a real crisis or a moral panic? 

No one is happy about youth vaping, but some perspective is necessary. It is possible to think of two categories of youth vaping: young people who would never have smoked or used nicotine in the absence of vaping, and people who would have gone on to smoke in the absence of vaping.  

For the latter group, there is a large benefit rarely discussed in politics or the media. These people would be more likely to come from poorer backgrounds, have parents who smoke, and have other disadvantages. 

We should be concerned about the young people trying vaping who never would have smoked, but the risks to them are quite low and likely to be transient, as this group would not have the strong psychosocial risk factors that would have inclined them to smoking. 

6. Has the public been misled by the media about the harms of vaping compared to smoking?

Yes, the public has been horribly and lethally misled. But I blame scientists, university press offices, well-funded activists and official agencies like the World Health Organisation for creating an environment where misinformation is created and thrives unchallenged. 

The media is just the final stage in a long supply chain of false and misleading scare stories about vaping and safer alternatives to smoking. Everyone involved is acting unethically, either through negligence or cynicism, to create a relentless flow of clickbait. We know that behaviour and intentions follow perceptions, so we can be pretty confident that this misinformation blitz is causing people to continue to smoke and, therefore, is likely to be killing people.

7. Why are some countries banning vaping while others are embracing it? 

There are only bad reasons and false justifications for banning vapes. There are three likely outcomes, and none of them are good. The first is adverse behaviour change, in which people smoke or adopt other risky behaviours. 

Second, an illicit market will develop in the products people want to use, but this will be unregulated and populated by rogue actors and criminal networks.  Third, users and suppliers will attempt work-arounds that may be risky. 

Some commentators argue that prohibition is a strong measure. I think it is the opposite. It is like a health regulator going missing in action and handing over responsibility for consumer health to police and customs officials. This approach failed completely in the war on drugs, and it will not work for vaping.

8. Do vaping bans and restrictions help improve public health? 

For most bans or restrictions on vaping, the unintended consequences will be the main consequences, either promoting smoking, causing illicit trade or driving workarounds. This type of restriction is generally aimed at preventing youth uptake. 

The other form of regulation is aimed at consumer protection and includes product safety, reliable information and packaging, responsible marketing, and age-secure retailing. Consumer protection regulation can boost confidence in products and help users have a better, safer experience. I would like to see more effort go into reasonable consumer protection and less on counterproductive measures to manipulate behaviours.

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