Indoor Air Quality

Indoor air quality (IAQ) plays a crucial role in public health, particularly since most people spend 80% to 90% of their time indoors. Modern building practices and lifestyle changes — such as airtight construction and limited natural ventilation — can allow a wide range of contaminants to accumulate without our immediate awareness. These pollutants include biological agents (e.g., mold, bacteria) as well as harmful gases (e.g., radon, carbon monoxide) that can contribute to respiratory issues, cardiovascular diseases, and even certain cancers. Understanding IAQ and adopting effective mitigation measures is critical for safeguarding health, especially in densely populated or industrial settings.

Where Do They Come From?

Indoor Air Quality (IAQ) refers to the presence of various pollutants—chemical, biological, or physical—within enclosed environments such as homes, offices, and schools. In contrast to outdoor pollution, which is frequently publicized, indoor contaminants often remain invisible and undetected without proper measurement tools. Because contemporary lifestyles involve spending extended periods of time in tightly sealed buildings, these pollutants can accumulate, sometimes reaching higher concentrations than outdoor levels. This accumulation poses significant health challenges—especially given that many of these pollutants are colorless and odorless. Pollutants of concern include:

Volatile Organic Compounds (VOCs): E.g., benzene, formaldehyde, toluene
Fine Particulate Matter (PM2.5 and PM10): Microscopic particles able to penetrate the respiratory tract
Gases: Radon (radioactive), carbon monoxide (CO), nitrogen oxides (NOₓ)
Biological pollutants: Mold, bacteria, viruses, dust mites, pet dander
Byproducts of activities: Emissions from cooking, heating, or smoking

Identifying common sources of these pollutants is the first step toward protecting yourself:

Everyday Household Activities
- Cooking, particularly with gas stoves, releases particulates (PM2.5), carbon monoxide, and nitrogen oxides.
- Many cleaning agents and air fresheners release VOCs when sprayed or evaporated.
- Tobacco smoke contains over 7,000 substances, including benzene and formaldehyde, that can linger in the air and settle on surfaces.
Building Materials and Furnishings
- Paints, adhesives, and pressed-wood furniture potentially release formaldehyde and other VOCs as they cure or off-gas.
- Mold thrives in poorly ventilated or humid environments, such as bathrooms and basements.
- Radon is naturally occurring, seeping in from the soil through cracks in foundations.
Insufficient Ventilation
- Modern constructions emphasize airtightness for energy efficiency, often trapping indoor pollutants.
- Poorly maintained or unbalanced HVAC systems recirculate contaminated air without adequate filtration or fresh air exchange.
Infiltration From the Outdoors
- Particles linked to traffic or industrial pollution (e.g., PM, nitrogen oxides), can infiltrate homes and workplaces through windows, doors, or inadequate filtration systems, further impacting indoor air quality.
- Seasonal allergens (e.g., pollen, spores), may also be carried in on clothing or through simple air exchange.

How They Affect You

Even though modern homes and offices tend to seal out noise and weather, they also trap pollutants that can quietly compromise our respiratory, cardiovascular, and cognitive health. Without proper ventilation, regular monitoring, and effective source control, these hazards often remain invisible to occupants. Vulnerable groups — including children, older adults, and individuals with chronic illnesses — are particularly at risk, as poorly ventilated or highly sealed buildings can trap contaminants, sometimes at concentrations exceeding outdoor levels.

Respiratory impacts: Elevated levels of particulate matter and allergens can exacerbate asthma, bronchitis, or COPD. VOCs or by gases like ozone or NO₂, can irritate the eyes, nose, and throat.
Cardiovascular risks: Long-term exposure to fine particles increases the likelihood of hypertension and heart disease. Certain combustion byproducts can induce systemic inflammation, affecting cardiac health.
Chronic illnesses and cancer: Radon is a leading cause of lung cancer, particularly for smokers in geographical areas naturally high in radon. Prolonged exposure to benzene and formaldehyde increases cancer risk. PM2.5 and PAHs are associated with various chronic health conditions and potential carcinogenic effects.
Cognitive and mental wellbeing: Fatigue, concentration difficulties, and heightened stress is linked to poor indoor air, including high CO₂ or VOC levels. Some VOCs (e.g., from solvent-based products), can affect mood and cognitive function over time.
Invisible hazards: Many harmful agents, such as carbon monoxide and radon, have no color or odor. In the absence of detection devices, occupants often remain unaware of dangerous concentrations.

How To Protect Yourself

While total elimination of indoor pollutants is not always feasible, diligent maintenance, informed choices, and mindful habits can substantially lower risks and foster safer indoor environments.

Ensure optimal ventilation: Open windows to air out rooms daily, even briefly, to reduce stagnant air. Use exhaust fans in kitchens and bathrooms to remove moisture and combustion byproducts. Ensure HVAC filters are replaced on schedule and ventilation ducts remain unobstructed.
Control pollution sources: Choose “low-VOC” or “VOC-free” paints, adhesives, and furnishings. Avoid indoor smoking, since tobacco smoke is among the most significant contributors to poor IAQ. Have gas stoves, furnaces, and water heaters inspected annually to prevent leaks or improper combustion.
Monitor and maintain your indoor environment: Fortunately, devices such as indoor air sensors, radon test kits, and carbon monoxide detectors can shed light on otherwise unseen problems. Radon testing is particularly crucial in high-radon zones. Seal cracks and improve underfloor ventilation if levels exceed recommended thresholds. Carbon monoxide detectors are essential wherever fuel-based appliances are used. Use an air purifier with a HEPA filter to capture fine particles, and an activated carbon filter to help reduce VOCs.

3 Essentials

Additional Key Recommendations

Indoor air sensors: Despite available technologies (e.g., sensors, ventilation systems, healthier construction materials), indoor air pollution often remains hidden, leading to prolonged or repeated exposure to unhealthy conditions. Connected devices can measure CO₂, PM2.5, VOCs, and other metrics in real time, rendering invisible pollutants visible.
Humidity control: Keep indoor humidity at 30–50%. Use dehumidifiers in damp areas and promptly address leaks or water damage to prevent mold growth.
Awareness and education: In many cases, awareness remains the first and most pivotal step. Educate household members, coworkers, and the broader community to significantly enhance prevention efforts and long-term outcomes.

References

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Work with a naturopathic doctor / naturopath to help you assess for environmental pollutants and to understand how they may be affecting your health. The information on this website is a guide for ways to protect you and your family from environmental pollutants. It is not meant to replace advice from a healthcare professional.