'Popcorn Lung' – Myth vs. Reality

One of the oldest, and most persistent, assertions about the dangers of vaping from the anti-vapor community surrounds a lung condition known as bronchiolitis obliterans, or 'popcorn lung.' Here, we'll take a look at the disease, what it means for people who are afflicted, and how it came to be associated with vaping, despite there being virtually no instances directly linking the disease to vapor products.

What is it?

To understand bronchiolitis obliterans (BO), you need to understand how the lungs work. When you breathe, air flows from your windpipe into two bronchi, one leading to each lung. These two tubes the split into four, four into eight, and on and on until the tiniest of the tubes, called bronchioles, end in small air sacs called alveoli. This is where oxygen from the air you're breathing enters your bloodstream.

When you're afflicted by BO, these bronchioles become irritated and inflamed, leading to scarring that shrinks the passageways to the alveoli, making it harder for oxygen to make it into your body. The result is that even when breathing normally you may find yourself feeling short of breath.

 BO is a chronic condition, meaning that it's both long-lasting and potentially recurring. Once you have it, the effects will likely stay with you for life.

Who gets it?

BO is primarily caused by two chemicals: acetaldehyde, a chemical found in marijuana smoke that could also pose harm to the mouth, throat, and stomach, is one.

The more common culprit, though, is diacetyl, and this is the chemical that gives 'popcorn lung' its name. Diacetyl is used as an artificial flavoring that gives foods a rich, buttery taste – it's the 'butter' in microwave popcorn.

The first cases of BO emerged among workers in factories that produce microwave popcorn in the early 2000s. These workers were exposed to large amounts of the chemical in the air for years on end, though more recent cases have been reported in factories that process coffee beans, as diacetyl occurs naturally in the beans and workers can be exposed to inhalation during the roasting process.

Improved safety regulations are being deployed to protect workers exposed to diacetyl on the job, though they still remain those most at risk. To date, there are only two highly-publicized cases of BO outside of workers in factory settings. One involved a Colorado man who ate two bags of microwave popcorn every day for more than ten years, another a Canada teen who mixed THC oil extracted from marijuana into his vape e-liquid while also smoking marijuana alone.

What's the vaping connection?

In the early days of vaping, some e-liquid manufacturers used diacetyl in their flavor recipes, particularly in crafting dessert and bakery-themed juices. Since diacetyl is present in the vapor produced by these liquids, opponents of vaping have latched onto the finding as a means of scaring would-be vapers into believing they'll contract BO.

What's left unsaid, however, is that diacetyl is also present in cigarette smoke – at levels hundreds of times higher than in any vapor product. If concerns about diacetyl and 'popcorn lung' in vapor e-liquids are stopping you from switching from smoking to vaping, it's important to be aware that you're already inhaling much more diacetyl than any non-smoker, including vapers.

Further, most e-liquid manufacturers began abandoning diacetyl and switching to alternative flavorings when the 'popcorn lung' campaigns began in 2016. It's officially banned by the UK and European Union, so it's a likely bet that any liquids available overseas do not rely on diacetyl as a flavoring, though nearly all US brands have also discontinued its use.

Do I need to worry?

In short, probably not. Most confirmed cases of BO involve extreme exposure over a prolonged period, and none have ever been tied directly to vaping. Exposure to the chemicals that cause the disease are much higher among smokers, though most cases among that population are likely tied to other lung diseases caused by the inhalation of tar and smoke generated by cigarettes.

If you're still concerned, check with your favorite e-liquid manufacturer. Most should be able to readily assure you that there's no diacetyl in their formulas, but if you don't get a satisfactory answer consider switching. Some vapers go so far as to avoid any flavors with buttery notes, though ultimately the choice of what to vape is up to you.