Understanding Air Quality: Particulate Matter and PM 2.5

Several years ago, after attending a session on forest fires and asthma outcomes at a conference hosted by Asthma Canada, I wrote an article on this topic, including some information on the impact of particulate matter 2.5 (or PM 2.5) on air quality. However, while I know it comes from byproducts of forest fire (and perhaps other smoke), I again really don’t know what PM 2.5 is.

And yes, these articles ARE truly a realization on my part that I’ve heard of all of these things but really do not know what they are. Thank goodness for the Internet!

Particulate matter defined

Per the Environmental Protection Agency (EPA), particulate matter, is a mixture of teeny tiny particles and liquid “droplets”—which size-wise I’d think of closer to something like mist versus raindrops!1 “Particle pollution” (which is sometimes used interchangeably with particulate matter) may be made out of various materials like “acids […], organic compounds, metals, and soil or dust particles.”1

What’s with the numbers?

The numbers associated with particulate matter (ie. PM 2.5, PM 10) are assigned based on the size of the particles, measured in micrometers. Thus, a PM 2.5 particle is less than 2.5 micrometers, and a PM 10 particle is 10 micrometers or smaller.1 To put that in context, the width of silk in a spider web is 3 to 8 micrometers2, whereas the film of plastic wrap (such as that found in your kitchen drawer) is generally 10 to 12 micrometers.3

Now I’ve spent far too much time sourcing the thickness of things to make this make sense. I qualify all this to note that particulate matter can be visible, but often won’t be easy to spot!

Particles 10 micrometers (often written as μm) or smaller are of most concern to the EPA.1 This is why you’ll see PM10, PM2.5, and PM0.1 most often discussed in the context of air pollution or health. Size matters, because the smaller the particles, the more chance they have to get through the body’s various defenses, into the lungs and bloodstream.4

PM 2.5 and health

Exposure to PM 2.5 can affect your lungs and heart.4 People with heart or lung disease, including asthma, are more likely to have health issues stemming from particle pollution exposure—this includes asthma or respiratory symptoms, decreased lung function, irregular heartbeat, nonfatal heart attacks, and even premature death related to heart or lung disease.4 This is why monitoring outdoor (and indoor!) air quality is important.

What can be done about particulate matter 2.5 (PM 2.5)?

Sources of PM 2.5 can be both indoors and outdoors. Indoor pollutants include smoking, cooking appliances, and even cleaning, as well as that which has entered from the outside (which is, needless to say, why it’s important to keep doors and windows closed on poor air quality days!).5

Outdoor sources of PM 2.5 include vehicle exhaust (cars, trucks, buses, and off-road vehicles including construction equipment and snowmobiles), fuel-burning (wood, oil, coal), forest and grass fires, and power plants.6 It’s important to note that wind can carry particulate matter in from geographic regions that may seem far away6—for example, during forest fires, here in Manitoba we may be affected not insignificantly by smoke from Alberta, and vice-versa.

In indoor environments, it is recommended that you maintain a smoke-free environment (of course!), run the stove-top fan while cooking5, stay away from using wood-burning fireplaces or stoves where possible—and even avoid burning candles.6

Using air quality alerts for outdoor air can help you take appropriate action to stay healthy1—on bad outdoor air quality days, staying inside can help unless your indoor air quality is also not good!5

Is PM 2.5 causing you problems?

It has been interesting to see for myself the fluctuations in my indoor air quality and PM 2.5 levels over the last couple of weeks while wearing a personal air quality monitor. As soon as I entered a Mongolian-grill style restaurant with a central flat-top grill, for example, the app began freaking out! Similarly, when food is being prepared at home, I often get an alert that my air quality has decreased—for a period of time, I often had asthma symptoms following dinner, and this makes sense now!

I guess I’ll be experimenting to see how my monitoring device responds to the use of the stove-top fan!

Disclosure: This post contains information stemming from my experiences with the Atmotube PRO personal air quality monitor. While this article is not a review of the product, out of an abundance of caution I choose to note that Atmotube sent me a device to use, for free, at my request to write about separate to Asthma.Net, with no other strings attached.

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This article represents the opinions, thoughts, and experiences of the author; none of this content has been paid for by any advertiser. The Asthma.net team does not recommend or endorse any products or treatments discussed herein. Learn more about how we maintain editorial integrity here.

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