Experts warn rising vaping rates bring emerging health risks as UK studies and seizures increase

Britons are vaping in unprecedented numbers while scientists and clinicians warn that the full health consequences of e-cigarette use are still emerging. Around 9.8 percent of adults vaped in 2023, rising to 15.8 percent among 16- to 24-year-olds, according to the Office for National Statistics, and experts say a growing body of research points to potential harms beyond those associated with smoking cessation.

Several recent studies have found biological and clinical markers of harm among people who vape. A 2023 paper in Nicotine & Tobacco Research reported DNA damage in mouth cells of vapers at levels similar to cigarette smokers, with the highest levels observed in users of pod-style devices. Researchers at Ohio State University reported in the Journal of Oncology Research and Therapy that people who both smoke and vape were four times more likely to develop lung cancer than those who only smoke, a result the authors said may reflect carcinogenic chemicals present in some e-liquids. A 2024 study in Tobacco Induced Disease linked chronic vaping to impaired blood vessel function, an early indicator of cardiovascular risk.

Public health specialists stress that while e-cigarettes are generally regarded as less harmful than combustible tobacco, they are not risk-free and may pose particular threats to young people. In February 2025 the UK Government launched a ten-year study that will follow 100,000 children and teenagers aged eight to 18 to track how vaping affects health over time. Andrew Grigg, professor of paediatric respiratory medicine at Queen Mary University of London, told journalists that children are being exposed to what he called “an experimental risk” as developing lungs are exposed to nicotine and a mixture of solvents and flavouring chemicals.

Researchers and clinicians point to several mechanisms that could explain observed harms. Nicotine, present in most legal and illegal e-liquids, is a vasoconstrictor that raises heart rate and blood pressure and may impair glucose regulation. Nicotine salts — used in many modern devices to allow higher concentrations to be inhaled smoothly — deliver doses closer to those from cigarettes and can sustain dependence. Laboratory and animal studies suggest the carrier liquids propylene glycol and vegetable glycerin, safe for ingestion, may affect lung cell function when inhaled; at high coil temperatures these compounds can degrade into formaldehyde and acrolein, known airway irritants and, in the case of formaldehyde, a carcinogen.

Flavouring chemicals used to produce tastes such as vanilla, cinnamon and cherry are another concern. Several compounds commonly used for flavouring are safe to eat but have shown toxicity to airway cells in lab tests when inhaled. Cinnamon-based cinnamaldehyde and benzaldehyde used in cherry flavours have been repeatedly implicated in cell damage and impaired ciliary function in the airways in experimental studies. UK-regulated products must not include additives known to be risky, such as diacetyl, which has been linked to bronchiolitis obliterans, but researchers have found such additives in products sold outside regulated markets and in illegal devices.

Metals may also leach from device heating coils into vapour. Studies published in Environmental Health Perspectives and other journals have detected nickel, chromium and lead in e-cigarette aerosols. Although concentrations are usually lower than in cigarette smoke, experts say cumulative exposure remains a concern, especially for long-term users.

Regulatory and market developments have further complicated the landscape. Trading standards officers in the UK reported seizing 1.19 million illicit vapes in 2023/24, a 59 percent rise on the prior year, while Border Force recorded a sharp increase in seizures at ports, from fewer than one million in 2022 to about 4.5 million between January and October 2023 and a further 1.14 million in 2024. Disposables were banned in Britain on June 1, 2025. Illegal products frequently exceed legal limits for nicotine, carry oversized tanks, lack child-resistant packaging or prominent nicotine warnings, use cartoon-style branding, or are sold with claims such as tens of thousands of puffs or high nicotine strengths. Some confiscated devices have tested positive for synthetic psychoactive substances, including “spice,” raising additional safety concerns.

Experts say distinguishing legal, regulated products from illicit ones can reduce risk. Legitimate UK e-cigarettes are reusable or refillable with pod or tank capacities no greater than 2 millilitres; e-liquids must be sold in 10 millilitre bottles with nicotine capped at 20 mg per millilitre. Packaging should include batch numbers, UK contact details and prominent nicotine warnings. The Medicines and Healthcare products Regulatory Agency (MHRA) maintains a public list of notified products that meet reporting requirements; notification is not a licence but indicates compliance with labelling and strength rules.

Despite the signs of harm, several public health authorities continue to regard e-cigarettes as a less harmful alternative for adult smokers who are unable or unwilling to quit nicotine by other means. Lion Shahab, professor of health psychology at University College London and director of the Tobacco Dependence Research Unit, said e-cigarette vapour is “far simpler” chemically than cigarette smoke and that exclusive vaping for at least six months has been shown to reduce exposure to many toxic and carcinogenic markers compared with smoking. He and other researchers stress that vaping should not be adopted by non-smokers and that the priority is helping smokers switch and ultimately stop using nicotine products altogether.

Clinicians and charities outline practical steps for users seeking to reduce risk or quit. Recommendations include using refillable products purchased from reputable UK retailers, using the lowest nicotine strength that controls cravings, keeping tanks topped up to avoid overheating and “dry puffs,” avoiding device modifications or mixing liquids, and seeking medical advice for chest pain, persistent cough or breathlessness. Battery safety guidance includes using supplied chargers and avoiding overnight charging.

A growing number of cessation tools have been adapted or studied for vaping. Text-message quit-support programmes have shown promise in adolescents; a US study reported a 35 percent higher quit rate at seven months among 13- to 17-year-olds enrolled in a text-based intervention. The Cochrane review has found text support may be effective for people aged 13 to 24. Pharmacological options used for smoking cessation, such as varenicline, have shown efficacy in reducing nicotine cravings and have been used off-label for vaping cessation; nicotine replacement therapies, including fast-acting mouth sprays, are also recommended by some clinicians to replicate the hand-to-mouth action of vaping while controlling nicotine intake. Behavioural strategies advised by stop-smoking services include spacing out puffs, reducing nicotine strength gradually and substituting other routines for the act of vaping.

Researchers caution that quitting vaping can be as difficult as quitting smoking because both involve nicotine dependence and similar withdrawal symptoms. The amount of nicotine consumed can vary widely by device and user behaviour; a 20 mg/ml e-liquid providing 600 to 800 puffs may deliver cumulative nicotine comparable to smoking one or two packs of cigarettes. Illegal devices with higher nicotine concentrations may increase dependence and complicate cessation.

Regulators, clinicians and scientists say long-term population-level research and continued surveillance of product composition and sales channels are essential. The government’s 10-year cohort study of children and teenagers aims to clarify the potential developmental harms of early vaping exposure, and ongoing laboratory and epidemiological studies are tracking biological markers, respiratory outcomes and cardiovascular signals in adult users. In the meantime, public health authorities continue to recommend that children, teenagers and non-smokers avoid e-cigarette use, while encouraging adult smokers to consider regulated vaping products only as a temporary aid to quit combustible tobacco and to seek support to stop nicotine entirely.