Indoor Air Quality Insights From Real-World Monitoring and How to Improve It

Indoor air quality (IAQ) is a critical but often overlooked aspect of health, especially as many people focus primarily on outdoor air alerts. Recent personal monitoring by three individuals across different U.S. cities using various air quality sensors has uncovered key insights into how indoor environments fluctuate and impact well-being.

Humidity and Particulate Matter

Humidity levels directly influence PM2.5 readings because many particulate matters are hygroscopic and swell with moisture, which can skew sensor data. Maintaining indoor humidity between 40-60% helps minimize dust mites and allergens, which thrive in higher humidity, thereby reducing allergy and asthma triggers.

Gas Appliances Elevate VOCs and CO2

Gas stoves, ovens, and fireplaces emit volatile organic compounds (VOCs), nitrogen oxides, carbon monoxide, and carbon dioxide due to combustion. These pollutants can cause respiratory irritation and worsen asthma. Even non-faulty gas appliances leak gases when off, highlighting the importance of proper ventilation and monitoring.

Ventilation’s Role in Sleep and Health

High indoor CO2 levels, common in poorly ventilated spaces, can impair sleep quality and cognitive function. Modern airtight homes often trap CO2, making ventilation essential, especially in bedrooms. Opening windows or using ventilation systems reduces CO2 buildup, promoting restful sleep and better concentration.

Common Household Pollutants and Their Sources

Several everyday items contribute to indoor air pollution: mattresses off-gas VOCs like flame retardants and phthalates; cleaning products with fragrances release irritants; cooking with certain oils and cookware increases particulate matter; and outdoor activities such as leaf blowing can introduce fine particles indoors through infiltration and HVAC systems.

Temperature, Pressure, and Air Quality Dynamics

While temperature and air pressure do not directly affect pollutants, they influence how materials off-gas VOCs and how pollutants infiltrate indoor spaces. Higher temperatures increase chemical emissions from household items, and negative indoor pressure can draw in outdoor pollutants like radon and smoke through cracks and vents.

Strategies to Improve Indoor Air Quality

Monitoring air quality empowers homeowners to identify pollutant sources and implement targeted solutions. Effective strategies include using HEPA and activated carbon air purifiers, improving ventilation, choosing low-VOC products, avoiding high-heat cooking methods indoors, and maintaining optimal humidity levels. These measures collectively reduce exposure to harmful indoor pollutants and enhance respiratory health.

By understanding the invisible threats in our homes, individuals can take proactive steps to create healthier indoor environments that support better sleep, reduce allergy and asthma symptoms, and improve overall quality of life.