E-cigarette users have been warned about everything from premature ageing to changes in DNA structure. Vapes and e-cigarettes began gaining ground in the nicotine-product market relatively recently, and for some researchers they remain an unknown quantity among alternatives to conventional cigarettes. While scientists debate vaping's effects on human health, other market participants take advantage of the situation. That is what happened, for example, with reports of a “vaping epidemic”, or more specifically, “popcorn lung”.
How it all began
In 2019, the world first heard about “popcorn lung” when a 17-year-old Canadian was diagnosed with a severe respiratory condition: bronchiolitis obliterans, a rare small-airway disease affecting the bronchioles, the terminal branches of the bronchial tree.
The disease had previously been reported among workers in factories producing microwave popcorn or roasted ground coffee. In 2019, doctors linked its development to vaping for the first time: the teenager reported using flavoured e-cigarettes daily for five to six months, also adding tetrahydrocannabinol, a substance derived from cannabis.
This was not the first case of severe respiratory disease among vape users. Around the same time, doctors in the US recorded 2,300 cases of breathing problems among e-cigarette users, 47 of whom died.
News of popcorn lung and related symptoms among vapers prompted extensive debate in medical circles and among manufacturers of alternative nicotine delivery systems. Health organisations and officials around the world urged potential users not to buy e-cigarettes.
What doctors say
Although opponents of vaping use the 17-year-old Canadian's case to argue for wider bans on alternative nicotine delivery systems, doctors are not endorsing the panic and are investigating the issue more closely.
According to Cancer Research UK, the world's largest independent cancer research organisation, popcorn lung is an unusual respiratory disease involving extensive scarring in the lungs that prevents air from reaching the alveoli. The information on its official website also states that no direct evidence has established a link between vaping and bronchiolitis obliterans.
Some researchers suggest that the damage is caused by exposure to diacetyl, a chemical present in most vaping liquids in varying proportions. Cancer Research UK stresses that vapes are relatively new to the alternative nicotine delivery market and are not guaranteed to be safe for human health. At the same time, its specialists cite research supporting e-cigarettes' potential to reduce cancer risk and their effectiveness in smoking-cessation treatment.
Experts around the world have publicly discussed using e-cigarettes and other alternative nicotine delivery systems to stop smoking conventional cigarettes. For example, a Public Health England (PHE) report prompted the European Parliament to recognise ANDS as a less safe alternative to smoking [sic in the source]. At the Global Forum on Nicotine (GFN) 2022, Lars M. Ramström, director of Sweden's Institute for Tobacco Studies (ITS), urged the World Health Organization (WHO) to stop ignoring scientific evidence supporting the use of ANDS to combat cancer worldwide.
Why is popcorn lung linked to vaping?
After the widely reported diagnosis of popcorn lung in a 17-year-old vaper, the media published numerous articles about the spread of vapes and ANDS among teenagers and their potential dangers to users' health.
Public concern is entirely natural and understandable. However, most readers overlooked doctors' observations that the teenager's airway injuries differed from those seen in other patients who had vaped, and that the cause of the so-called vaping epidemic had still not been officially established.
A study published in EHP in 2016 dealt a significant blow to the reputation of vapes and ANDS. It examined the health effects of diacetyl, pentanediol and acetoin found in some vaping liquids. In that work, researchers analysed the composition of many commercially available vape and e-cigarette liquids for the first time and suggested that respiratory diseases among vapers were linked to high levels of diacetyl in flavoured formulations. The study also referred to US legal cases in which microwave-popcorn factory workers who had developed bronchiolitis obliterans sought compensation from manufacturers of sweet food flavourings containing diacetyl.
The researchers arrived at their conclusion that diacetyl in vaping liquids was the main source of popcorn lung as follows: they selected 51 liquids with flavours they considered especially appealing to young people. These liquids were tested for 3-hydroxy-2-butanone, acetyl propionyl and diacetyl.
The research team reported the following results:
- At least one of the three chemicals was found in 47 of the 51 liquids
- Diacetyl was detected in 39 of the 51 liquids
- 3-hydroxy-2-butanone was found in 46 of the 51 liquids
- Acetyl propionyl was detected in 23 of the 51 liquids
The researchers concluded by urging regulators to take immediate steps to restrict the spread of vapes and ANDS in local markets.
What is really going on?
Alex Kröix, founder and editor of belvaping.com, one of the largest Russian-language vaping publications, analysed the study on the effects of diacetyl, pentanediol and acetoin on the development of popcorn lung.
According to the journalist, the study's conclusions raise questions. He noted, for example, that in 33 of the 51 liquids, diacetyl was either not detected or was present at no more than 2.4 µg.
Adding those figures and dividing by 51 gives an average of 9 µg. If that amount is taken to correspond to daily liquid consumption, a vaper using these liquids could be assumed to receive an average of about 9 µg of diacetyl per day.
Meanwhile, the smoke from one tobacco cigarette contains between 301 and 433 micrograms of diacetyl. Taking a pack of 20 cigarettes as average daily consumption, a smoker receives between 6,020 and 8,660 µg of diacetyl a day.
The lowest exposure previously recorded for a factory worker who developed bronchiolitis obliterans was 2,864 µg over eight hours. The 9 µg per day found by Joseph G. Allen and his colleagues is, of course, hardly what one could call a “risk factor”.
The conflicting findings of researchers studying the issue show that the scientific community still has no consensus that vapes cause popcorn lung. It is also known that tobacco-industry representatives conduct large-scale information campaigns against vaping companies in an effort to retain their position in a market increasingly captured by manufacturers of alternative nicotine products. A notable case occurred in 2019, when North Carolina sued JUUL Labs, one of the world's most successful vape manufacturers. The case resulted in the US Food and Drug Administration (FDA) banning sales of JUUL Labs e-cigarettes in the country.
Such attacks on vaping inspire little confidence among either ANDS users or industry representatives. For example, Michael Landl, director of the World Vapers' Alliance, commented on the European Commission's bias against ANDS:
It is shocking that the European Commission is still peddling these tired, long-debunked theories. The Commission systematically ignores the wealth of scientific evidence pointing to the benefits of vaping, not to mention the personal experience of millions of vapers. Vaping is 95% less harmful than smoking and is more effective for quitting than traditional treatments such as gum and nicotine patches. The Commission's approach to vaping will achieve nothing, but it will cost lives.
How to look after yourself
Whatever your views on vaping and ANDS, there are several ways to look after yourself and your health.
- If you do not smoke conventional cigarettes or use ANDS, do not start.
- If you smoke conventional cigarettes, switch to vapes or ANDS and set yourself the goal of giving up nicotine for good.
- If you use vapes or ANDS, have regular medical check-ups and chest X-rays, and monitor your overall well-being. If your condition worsens even slightly, stop using the device and see a doctor. We also recommend buying vapes, e-cigarettes and other ANDS from authorised distributors.
- Do not panic. Check information and choose carefully the sources you use to learn about the products you use and your preferred ANDS manufacturers.
