In This Blog

Heat + Sun + Pollution = Smog

As someone who leans into natural health, clean eating, and holistic self-care, I’ve learned to pay closer attention to air quality as a health metric—especially in summertime. When the sky turns hazy, the air smells off, or outdoor physical activity feels like a lot more effort than usual, I take my activity inside. If you think I’m being overly cautious, consider these facts:

What Happens When You Exercise in Polluted Air

When we’re physically active, we’re breathing deeper and faster. That means we're pulling in more airborne pollutants—like fine particulate matter, ozone, and nitrogen dioxide—deeper into our lungs. Over time, this can inflame the lungs and airways, weaken immune defenses, and trigger or worsen asthma and allergies. Pollution exposure also increases oxidative stress and cellular damage, which are widely regarded as key influencers of disease and the aging process.

Key Factors That Affect Outdoor Air Quality

Hot weather doesn’t just make things uncomfortable—it magnifies air pollution. Sunlight reacts with airborne chemicals (like nitrogen dioxide and VOCs) to form ozone, which further irritates the lungs. Add in the phenomenon of temperature inversions—a weather pattern that traps pollution close to the ground—and even a walk in the park can start to feel like breathing through a wool scarf on a humid day.

Here are some key factors that affect outdoor air quality:

• Population density: More motor vehicles means more emissions.
• Proximity to factories or refineries that release toxic by-products into the air
• Humidity and heat levels: These trap fine particles and make air more difficult to breathe
• Local geography: Valleys trap pollutants more easily because of their bowl shape
• Wildfires and wind patterns carry smoke hundreds of kilometers from its source

So even if the air “looks fine” to you, it’s a good idea to check the Air Quality Health Index (AQHI) before stepping out to exercise. Public health agencies in Canada recommend avoiding physical exertion when the AQHI is rated 7 or higher (indicated by the words ‘High’ or ‘Very High risk’).

The Truth About Masks and Wildfire Smoke

Let’s clear the air on mask recommendations.

Public health messaging often suggests wearing a mask when smoke levels are high—but they don’t always specify what kind.  Forget surgical masks and cloth masks; they don’t filter out the fine, solid particles found in wildfire smoke - - nor the gases. Only N95 respirators filter out PM2.5, the fine particulate matter that causes the most harm to your respiratory system. A well-fitted N95 mask can reduce your inhalation of particulate matter—which is especially helpful on smoky days.

But here’s where it gets trickier: N95s do not filter out VOCs—the gaseous chemical by-products of smoke. For that, you'd need a specialized industrial respirator, like what renovators and mould remediators wear. These bulky but effective masks contain activated carbon cartridges designed for chemical vapours -- - not just dust and smoke particles. But unless you have occupational exposure or have been diagnosed with a chronic lung disease you may rather stay indoors than wear one of these.

Indoor Air Isn’t Always Better

Be aware that retreating indoors doesn’t always guarantee ‘better’ air quality.

Many of today’s well-insulated, energy-efficient homes are air-tight—great for keeping smoke out, but terrible if you trap indoor toxins inside. Without proper ventilation, you may also be encouraging mould growth, especially in humid areas. That “airtight” house can slowly become a toxic microclimate. That’s why on days with a high outdoor Air Quality Health Index (AQHI) rating, you should set your HVAC system to recirculate if possible, so that outdoor air isn’t sucked in. Definitely turn off the fan if it pulls outdoor air inside (this is the default setting for many home HVAC systems).

Choose Filtration Over Fragrance

Have you ever visited a place that smells like they’re trying to hide bad air with artificial fragrance? So-called “air fresheners” only mask odours with synthetic chemicals—many of which are respiratory irritants themselves. Don’t confuse air fresheners with air purifiers. True air purifiers are machines equipped with HEPA + activated carbon filters to physically remove particles like PM2.5, pollen, and VOCs from the air. If clean air is your goal, choose devices that filter, not fragrance. If a HEPA filter isn’t in your budget right now, run your bathroom and kitchen exhaust fans regularly to help remove household fumes and other pollutants in your air. And don’t add to the problem by using artificially fragranced laundry and cleaning products. After all, clean air should have virtually no odour.

Natural Ways to Support Your Body on High-Risk AQHI Days

Check the AQHI before heading out. Use your local weather service or Environment Canada’s website to monitor the Air Quality Health Index (AQHI). Avoid outdoor exercise when AQHI is over 7—especially if you have asthma, allergies, or respiratory issues.

Exercise early in the morning. Heat, pollution and ozone levels tend to peak in the late afternoon. Mornings usually offer cleaner air, and tend to be cooler, too.

Choose the right location for your exercise. Parks with dense tree cover or trails away from roads often have better air quality than city streets.

Mask with purpose. A well-fitted N95 mask can reduce inhalation of particulate matter—especially helpful on smoky days.

Recover indoors. After your workout, give your body time to recover in clean, filtered air.

Ventilate your indoor space regularly and consider a HEPA air purifier to keep indoor air clean.

Protect yourself with antioxidants. Glutathione is your body’s most powerful free radical scavenger, neutralizing highly reactive chemicals capable of cellular damage - - but reduced glutathione supplements are poorly absorbed. A more efficient way to boost your glutathione levels is to take glutathione-builders, like NAC (n-acetyl-l-cysteine) and selenomethionine. Compared with other antioxidants, NAC has the highest affinity for protecting the lungs from free radical damage caused by ozone, VOCs and particulate matter. It can be paired with selenomethionine - - a highly bioavailable, organic form of the mineral selenium with the added antioxidant benefits of the amino acid methionine. Other supportive antioxidants include Vitamin C, Vitamin E and various phytochemicals found in dark-coloured fruits, vegetables and spices.

Move Mindfully In Hot, Humid and Smoggy Air

As someone invested in natural health, I’ve learned to treat air quality as part of my wellness routine. Just like I read food and supplement labels or choose organically grown foods when I can, I now check the AQI before I go out for a bike ride or swim. I keep an N95 mask on hand to wear when skies are smoky, and I up my antioxidant support—like NAC, selenomethionine and vitamin C—when it’s harder to avoid polluted air. Staying active shouldn’t come at the expense of our lungs. Breathing is rather important, and as vital as the food we eat. So check the air before you move, support your lungs like you do your muscles, and make clean breathing part of your natural health routine.

References

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Government of Canada. “About the Air Quality Health Index”. Accessed online July 3, 2025.

Government of Canada. “Wildfires in Canada: Toolkit for Public Health Authorities”. Updated July 2024.

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