Wildfire smoke is an indoor problem, too

Hey there, time traveller!
This article was published 08/08/2025 (315 days ago), so information in it may no longer be current.

Zoe Pierce’s recent article (An unavoidable future, July 31) rightly highlights how worsening air quality from this summer’s wildfire season is affecting outdoor athletes in Manitoba. But the conversation can’t stop there. While it’s important to protect players running drills on smoky fields, we need to talk about the rest of us, quietly breathing in the same polluted air, hour after hour.

Poor air quality is affecting all of us in Manitoba this summer. We are still new to the realities of wildfire smoke as a public health threat. Even if some of us are checking the Air Quality Health Index (AQHI) or using sensors to track fine particulate matter in the air around us, few understand what those numbers really mean — or the health risks that come with prolonged exposure.

Most of us spend about 90 per cent of our time indoors, and many of our homes, offices and public buildings are simply not equipped to keep people safe during the hazardous air that comes with widespread wildfires. Older buildings were not designed to manage the sustained presence of wildfire smoke.

With climate change making wildfire seasons longer, more severe and more frequent, the long-term health consequences including respiratory issues, cardiovascular stress and pregnancy complications are only getting worse. The truth is, we don’t have adequate indoor air filtration in most buildings. That’s not just a design issue — it’s a policy failure.

Standards for indoor air quality have not been set in legislation or regulation anywhere in North America and no mechanism for enforcement is available if their poor air quality is present. By law, buildings in Manitoba have minimum heating levels while strict occupational health limits exist for high carbon dioxide levels in workplaces. The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) provides clear comfort guidelines for filtration and ventilation levels.

However, most buildings don’t follow those standards because they don’t have to. There are no mandatory regulations in place, in Manitoba or virtually anywhere else in the world, to safeguard air quality indoors, even though the science is clear and the health risks are significant.

When the air outside is visibly smoky, many people close their windows and assume they’re safe. But unless your building is filtering incoming air at a high enough level, you are still being exposed to contaminated air. Most HVAC systems bring in outdoor air as part of their ventilation process. If those systems aren’t filtering properly, or if filters aren’t replaced frequently enough, you’re still breathing that wildfire smoke inside.

The impact of breathing in contaminated air can lead to mild symptoms such as brain fog and fatigue, itchy eyes, or scratchy throats (what we might call “sick building syndrome”). It can also aggravate more severe symptoms for people with existing respiratory issues. People with asthma, young children, the elderly, pregnant individuals and those with chronic illnesses are especially vulnerable to poor indoor air quality. For them, a smoky summer day isn’t just unpleasant. It’s dangerous.

This is especially true in buildings where systems are larger, older or harder to modify quickly. That said, there are solutions that can be quickly accomplished in any building. Upgrade your existing furnace or HVAC filters, add portable air cleaners with HEPA filters or seal off air intakes temporarily during high-smoke days. These aren’t complex or expensive retrofits and this situation of prolonged wildfires absolutely calls for it.

So why isn’t more being done? In short: because no one is measuring and enforcing it.

Until there is a mechanism in place to measure and regulate indoor air quality much of the responsibility falls to individual building owners, employers and tenants to protect themselves and their communities. That means office managers, school administrators and landlords need to step up, in the absence of regulatory change by policymakers. If we’re serious about public health — and about adapting to a future shaped by climate change — we need standards for indoor air filtration. And we need them soon.

Fortunately, we don’t have to wait for government to act. Individuals can begin by tracking indoor air quality in their own spaces. Low-cost sensors are widely available and can provide real-time data on how clean air is. If the air is bad, act: ask your building manager to upgrade filters or bring in additional temporary filters. In a pinch, you can build a DIY filter using a box fan and a furnace filter. This can have an immediate impact on your well-being.

We need to start treating wildfire smoke events as the public health emergencies they are. Smoky skies are changing how we play, train and compete outdoors. But they’re also quietly changing how we live indoors. We may not all be athletes doing high-intensity training outdoors, but that doesn’t mean our lungs are safe from short- and long-term risks associated with poor air quality.

We can’t see the smoke when we’re inside. That doesn’t mean it isn’t harming us. This summer has made it painfully clear: the air around us is getting worse. It’s time we started acting like it.

Matt Schaubroeck is an advocate for increasing air quality solutions within buildings.