Smoke Signals: How Outdoor Air Quality Affects Workplace Safety

Ashley: Hello and welcome to Safe and Sound with CCOHS. Smoky skies and hazy days from wildfires and other sources are becoming more frequent all across Canada, and the resulting air quality can affect both indoor and outdoor workers. Joining me today to talk about it is Matea Kokorovic, senior technical specialist here at CCOHS. Welcome, Matea!

Matea: Thanks, Ashley, happy to be here.

Ashley: So, let's start with the basics. Why is outdoor air quality suddenly such a big concern for workplaces?

Matea: Well, it comes down to what's driving it. Poor air quality can come from human activity, but also from natural sources like wildland fires, dust storms, and pollen. And with climate change, we're seeing wildland fires happen more often, which is really reducing air quality in a lot of communities. For employers, that matters because they have a duty to protect workers from hazards in the workplace. That includes hazards in the air, even outdoors.

Ashley: Right, it's easy to think of air quality as just a weather event, but if your workers are outside breathing it in all day, it's an occupational safety issue, too.

Matea: Exactly. And the symptoms – eye irritation, extra mucus in the nose or throat, coughing, trouble breathing – they can affect otherwise healthy workers, especially if they're doing physically demanding work outdoors. Exertion tends to make breathing difficulties worse.

Ashley: What about workers who might be more vulnerable to begin with?

Matea: That's an important piece of this. Older workers, pregnant workers, and workers with existing health conditions like cancer, diabetes, allergies, or heart and lung disease, can experience stronger or more frequent symptoms. And here's the thing: some workers might not even know they have a condition that poor air quality could aggravate. So putting precautions in place isn't just for the workers you know are at risk, it benefits everyone.

Ashley: How do we know exactly how bad the air quality is on a given day?

Matea: Most of Canada uses the Air Quality Health Index to communicate that. Québec has its own version called the Info-Smog program. The index runs on a scale from 1 to 10+. 1 means safe conditions, and anything above 10 is considered very high-risk. Most weather apps and television networks report the air quality health index right alongside the regular forecast, so it's easy to find.

Ashley: And I imagine the advice changes as that number climbs?

Matea: It does. At low risk, usual outdoor activities for everyone are typically fine. At moderate risk, which is 4 to 6 on the scale, employers should consider reducing or rescheduling strenuous outdoor work, especially if workers have symptoms like coughing or throat irritation, or if they have a medical condition that could affect their ability to work safely. At high risk, 7 to 10, employers should reduce or reschedule strenuous outdoor activity altogether, plus taking extra precautions for older or more vulnerable workers. And at very high risk, above 10, strenuous outdoor work should be avoided completely, and alternate work activities should be scheduled. At any point if workers feel that the air quality is unsafe, they should report that to their employer or supervisor.

Ashley: And at a certain threshold, regions will also put out their own air quality alerts through local news channels, correct?

Matea: Right. Those get issued when conditions are expected to reach hazardous levels for the general population. They're usually shared through your local weather network or weather app, and they're colour-coded to reflect the level of risk. It's worth checking how your specific region communicates these alerts, since that can vary by location.

Ashley: What should employers be doing to prepare for all this?

Matea: The first step is building poor air quality events into your workplace's emergency preparedness plan, and making sure workers are trained on what that plan involves. From there, it really helps to do a risk assessment for outdoor and indoor workers separately, because the right response depends on both the health risk category of the air quality health index and the type of work being done.

Ashley: Let's start with outdoor workers. How can employers best protect them?

Matea: A few options, depending on health risk category. You can limit the amount of time spent outside, provide more breaks, shift outdoor tasks to a time when air quality is expected to improve, or in more severe conditions, cancel outdoor work entirely. If the work absolutely has to happen, make sure workers have the right training and the appropriate personal protective equipment, based on a proper risk assessment.

Ashley: And for indoor workers, is it as simple as just staying inside?

Matea: Not quite. The goal is really about keeping that outside air from getting in. That can mean adjusting your HVAC system to recirculate indoor air rather than draw in air from outside, keeping windows closed, sealing gaps in windows and doors, and running an air purifier if you have one. Also make sure any air filters in your HVAC system have the right rating, ideally a MERV rating of 13 or more, and are being replaced on schedule.

Ashley: It sounds like a big takeaway here is that this isn't a rare, once-in-a-while event anymore.

Matea: That's exactly it. Poor air quality is becoming a regular part of the year for a lot of workplaces, so it deserves a spot in standard safety planning, not just a reaction when smoke shows up. Checking the air quality health index regularly, knowing which workers may be more vulnerable, and having a clear plan ready before smoke or dust rolls in are all things that can be done to keep workers healthy.

Ashley: Matea, thank you so much for walking us through this.

Matea: It's always great to be here.

Ashley: And to our listeners, there are a lot more resources on this topic on our website, CCOHS.ca. Thanks for listening and stay safe out there!