Indoor Air Quality
The quality of air inside buildings, which can be 2-5 times more polluted than outdoor air due to poor ventilation and indoor sources.
Detailed Explanation
Indoor air quality (IAQ) refers to the air quality within and around buildings and structures, particularly as it relates to the health and comfort of occupants. The EPA estimates that Americans spend approximately 90% of their time indoors, where pollutant concentrations can be 2 to 5 times higher than typical outdoor levels. Indoor air pollutants include particulate matter from cooking (especially gas stoves), volatile organic compounds (VOCs) from building materials, furniture, and cleaning products, carbon monoxide from combustion appliances, radon gas from soil, biological contaminants like mold and pet dander, and environmental tobacco smoke. Poor ventilation is the primary factor in elevated indoor pollutant levels — modern energy-efficient buildings can trap pollutants inside. The relationship between indoor and outdoor air quality is complex. On days with poor outdoor AQI, staying indoors with windows closed can reduce exposure, especially with air filtration. However, indoor sources can create pollution levels that exceed outdoor air on even the worst AQI days. Gas stove use, for example, can produce indoor NO2 levels that would exceed EPA outdoor standards. AirHistory tracks outdoor ambient air quality as measured by EPA monitors. For a complete picture of air quality exposure, individuals should consider both their city's AQI trends and their indoor environment, including ventilation, cooking methods, and the use of air purifiers.
Related Terms
PM2.5 (Fine Particulate Matter)
Airborne particles smaller than 2.5 micrometers in diameter — small enough to penetrate deep into the lungs and enter the bloodstream.
Volatile Organic Compounds (VOCs)
Carbon-containing chemicals that easily evaporate at room temperature and contribute to ozone formation and direct health effects.
Carbon Monoxide (CO)
A colorless, odorless gas produced by incomplete combustion of carbon-containing fuels, primarily from vehicles and industrial processes.
Sensitive Groups
Population groups more vulnerable to air pollution, including children, older adults, pregnant women, and people with heart or lung conditions.
Frequently Asked Questions
The quality of air inside buildings, which can be 2-5 times more polluted than outdoor air due to poor ventilation and indoor sources.
Indoor air quality (IAQ) refers to the air quality within and around buildings and structures, particularly as it relates to the health and comfort of occupants. The EPA estimates that Americans spend approximately 90% of their time indoors, where pollutant concentrations can be 2 to 5 times higher than typical outdoor levels. Indoor air pollutants include particulate matter from cooking (especially gas stoves), volatile organic compounds (VOCs) from building materials, furniture, and cleaning products, carbon monoxide from combustion appliances, radon gas from soil, biological contaminants like mold and pet dander, and environmental tobacco smoke.