You Spend 90% of Your Life Indoors. How’s the Air?

The most important air you breathe isn’t the air outside.

Most of us spend an enormous amount of time indoors — at home, in offices, in cars. According to data from the U.S. Environmental Protection Agency, the average person spends approximately 90% of their time inside. Health Canada has reached similar conclusions for Canadians.

That statistic alone might not alarm you. But here’s the part that should: the EPA also reports that indoor air concentrations of some pollutants are often 2 to 5 times higher than typical outdoor air.

Think about that. We worry about air quality alerts when wildfire smoke rolls across Alberta. We check the Air Quality Health Index before outdoor exercise. But we rarely think about the air inside our own homes — the air we breathe most of the time.

What’s Actually in Your Home’s Air

Indoor air is a complex mixture. The most common pollutants found in Canadian homes include:

Fine Particulate Matter (PM2.5) — Tiny particles less than 2.5 microns across that can penetrate deep into your lungs. They come from cooking, candles, pet dander, outdoor pollution that drifts inside, and HVAC systems that haven’t been properly maintained.
Volatile Organic Compounds (VOCs) — Gases released from cleaning products, paints, furniture, and building materials. Many are odourless. Some are associated with long-term health effects.
Carbon Dioxide (CO₂) — A byproduct of breathing. In poorly ventilated spaces, CO₂ builds up quickly. Research from Harvard’s Healthy Buildings Program has examined its relationship with cognitive performance.
Radon — A naturally occurring radioactive gas that seeps into homes from the soil beneath them. Health Canada considers radon the second leading cause of lung cancer in Canada after smoking. Alberta has significant radon concentrations.
Mold Spores — Produced wherever moisture and organic material meet. Common in bathrooms, basements, and around windows. Associated with respiratory disease and allergic reactions.
Dust and Allergens — Pet dander, dust mites, and pollen can accumulate in carpets, upholstery, and HVAC systems, continuously circulating through your home.

Why Alberta Homes Face Unique Challenges

Alberta’s climate creates specific indoor air quality challenges. Our long, cold winters mean homes are sealed tight for months at a time — which reduces natural ventilation and allows indoor pollutants to accumulate.

Data from Bosonea et al. (2020), published in *Allergy, Asthma & Clinical Immunology*, shows that asthma prevalence among Alberta females increased threefold between 1995 and 2015 — from 3.9% to 12.3%. By 2015, nearly 497,000 Albertans were living with physician-diagnosed asthma.

These numbers don’t point to a single cause. But the pattern is worth paying attention to.

Who Is Most at Risk

Not everyone is equally affected by poor indoor air quality. Research consistently shows that women, children, the elderly, and people with pre-existing respiratory or cardiovascular conditions are most sensitive.

Emerging research has also identified a connection between air pollution and female hormonal health — particularly during perimenopause. A 2023 study using the SWAN longitudinal cohort found that air pollution exposure is associated with lower estradiol levels in midlife women. We’ll explore that research in depth in a future article.

What You Can Do Right Now

The good news: indoor air quality is one of the most improvable aspects of your home environment.

1. Change your furnace filter regularly — at minimum every 90 days, more often if you have pets or allergies. Use a MERV-11 or higher filter.

2. Test for radon — inexpensive radon test kits are available at hardware stores, or you can request a professional measurement. If your result is above Health Canada’s guideline of 200 Bq/m³, mitigation is straightforward.

3. Maintain indoor humidity at 40–50% — too dry or too humid both create problems. A simple hygrometer costs under $20.

4. Ventilate deliberately — if you have a heat recovery ventilator (HRV), make sure it’s set to run continuously. If not, open windows briefly each morning to exchange stale air.

5. Book a professional indoor air quality assessment — a trained technician can measure PM2.5, VOCs, CO₂, radon, humidity, and other factors in your specific home and give you a personalized action plan.

A Different Way to Think About Home Wellness

Most of us invest in good nutrition, physical fitness, and sleep hygiene. We think carefully about what we put into our bodies and how we take care of them.

The air you breathe is no different. You inhale approximately 11,000 litres of air every day. What’s in that air shapes your health in ways that compound over time.

A home that actively manages its indoor environment isn’t a luxury — it’s a logical extension of the wellness lifestyle many Alberta families are already living.

Next: Harvard Study: How Office Air Quality Affects Cognitive Performance →

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Sources: U.S. Environmental Protection Agency, Indoor Air Quality; Health Canada Environmental Health; Bosonea et al. (2020), Allergy, Asthma & Clinical Immunology (PMC7547457)

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Ready to Breathe Easier? Start with a Home Wellness Assessment.

Alberta Indoor Comfort’s WellnessByHome team tests what your home is actually doing to your health — air quality, humidity, ventilation, radon, and water quality — in a single visit.

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