Air Quality (PM2.5 & Ozone)
Environmental Risk Factor
Air quality measures the concentration of harmful pollutants in outdoor air that you breathe every day. The two most significant pollutants are fine particulate matter (PM2.5) — tiny particles less than 2.5 micrometers that penetrate deep into the lungs and bloodstream — and ground-level ozone, which forms when sunlight reacts with vehicle and industrial emissions. Poor air quality disproportionately affects children, the elderly, and those with respiratory conditions. Cities in valleys, those with heavy traffic, and areas near industrial operations tend to have the worst air quality. Wildfire smoke has become a growing seasonal contributor to poor air quality across the western United States.
How It's Measured
Air quality is measured using the Air Quality Index (AQI), a scale from 0 to 500 developed by the EPA. Values under 50 are considered good, 51-100 moderate, 101-150 unhealthy for sensitive groups, 151-200 unhealthy, 201-300 very unhealthy, and above 300 hazardous. The AQI tracks six pollutants: ground-level ozone, particulate matter (PM2.5 and PM10), carbon monoxide, sulfur dioxide, and nitrogen dioxide. Monitoring stations across the country collect real-time data reported through AirNow.gov.
Health Effects
- ⚠️Aggravated asthma and respiratory diseases
- ⚠️Decreased lung function and lung development in children
- ⚠️Increased risk of heart attacks and strokes
- ⚠️Premature death from long-term exposure
- ⚠️Increased cancer risk from certain pollutants
- ⚠️Neurological effects including cognitive decline
Data Sources
- 📊EPA AirNow monitoring network
- 📊American Lung Association State of the Air report
- 📊NASA satellite-based air quality data
- 📊State environmental agency monitoring stations
How to Protect Yourself
- ✓Check AirNow.gov daily for local air quality forecasts
- ✓Limit outdoor exercise when AQI exceeds 100
- ✓Use HEPA air purifiers indoors during poor air quality days
- ✓Keep windows closed and run HVAC on recirculate mode when air quality is poor
- ✓Wear N95 masks during wildfire smoke events
- ✓Support policies that reduce vehicle and industrial emissions in your area