Ash Scotland is a separate charity from the main UK ASH (Action on Smoking and Health). However, it has the same penchant for occasional ill-advised comments that seem to target and discredit smoking-alternative products more often than cigarettes.

In a recent X post. ASH Scotland linked to a STV News piece with CEO Sheila Duffy, where she shares “her thoughts and expertise on vape-free spaces,” by comparing vape vapour particulates to air pollution.

Let’s take a look.

Expertise

Perhaps it's just unfortunate wording, but readers of ASH Scotland’s post or the linked article could be forgiven for believing that Sheila Duffy is being presented as an authority on air pollution.

While there is no doubt that Duffy is an experienced CEO (she’s helmed ASH since 2008), when Duffy compares vape vapour particulates to "air pollution," she's making a technical scientific claim on behalf of a government-funded organisation. However, her background is not in STEM; she has an MA in English Literature.

Now I’m not saying that with a bit of work and learning, you couldn’t master the science behind air pollution. But, having read her comments, Duffy is not there yet.

Particulates

Here is what Duffy says:

There is emerging evidence about vapour—whether from vapes, heated tobacco, or heated herbal products—that it carries the kind of particulates that we see cause disease with air pollution, and that it carries toxic chemicals.

There is a lot here, so we’ll take it in sections.

“Emerging evidence”

Ah, yes, the evidence is always emerging. It’s just over the hill; it’s there potentially, but it never fully emerges. Much of the time, emerging evidence is a byword for weak evidence that says something that researchers and funders really want it to say, but will be torn apart by robust peer review or expert analysis should it ever truly emerge.

Particulate comparison

Duffy claims this emerging, yet uncited, evidence involves particulates associated with air pollution-caused disease. But how credible is this claim?

A vape device emitting vapor next to a microscopic image of air pollution particulates.

First off, Duffy is correct that vapes create tiny airborne particles. But when she says “similar to air pollution”, what does she mean? Is she saying:

  1. Vapes emit some kind of particulates.
  2. Vapes emit the kind of particulates that we see with air pollution.

I don’t see how her statement, vague as it is, can read as anything but b. It’s important to note that what particulates are made from is what determines the harm they do.

What are particulates?

For the science illiterate, like Duffy (jokes), here is a quick definition of particulates.

Particulates, also called PM2.5, are tiny stuff floating in the air smaller than 2.5 micrometres. The reason their size is important is that particles of 2.5 micrometres and lower are small enough to bypass your body's natural defences, enter your bloodstream, and penetrate deep into your lungs.

However, not all particulates are equally dangerous.

Air pollution particulates vs. vape aerosol particulates

When Duffy claims vapes carry particulates that are similar to air pollution, she is gravely mistaken or lying.

Air pollution particulates contain:

  • Black carbon from burning things like diesel fuel, coal, or tobacco.
  • Polycyclic Aromatic Hydrocarbons (PAHs) from burning organic matter.
  • Heavy metals from industrial processes, fuel combustion, and brake dust.
  • Sulfates and nitrates that cause things like acid rain.

Vape aerosol particulates contain:

  • Propylene Glycol, a food-grade ingredient.
  • Vegetable Glycerine, a non-toxic sweetener.
  • Nicotine, a non-cancerous stimulant.
  • Food-grade flavour additives.

Now, you don’t need to be a genius to understand there is a difference between these air pollutants and vape aerosol particulates. Listen to Duffy, and you’d think hanging around in a vape shop was the same as being in a busy motorway tunnel. They’re not. If she were given a choice of pulling 8-hour day shifts in either environment, you know what she’d choose if she were concerned about her health.

Final thoughts

ASH Scotland’s attempt to sell us on Sheila Duffy’s expertise is unacceptable. Her background is in education, which means she should be able to deliver clear, elucidating messages. Instead, she seems happy to mislead and confuse the Scottish public by claiming equivalence between soot and vaping based on the size, not the content, of the particulates.