Complete Air Quality Guide
Everything you need to know about air quality index (AQI), health impacts, and how to protect yourself from air pollution
What is the Air Quality Index (AQI)?
The AQI is a standardized scale from 0 to 500 that measures air pollution levels and tells you how clean or polluted your air is, and what associated health effects might be of concern.
How AQI Works
The AQI focuses on health effects you may experience within a few hours or days after breathing polluted air. The EPA calculates the AQI for five major air pollutants regulated by the Clean Air Act:
- Ground-level ozone (O₃)
- Particle pollution/particulate matter (PM₂.₅ and PM₁₀)
- Carbon monoxide (CO)
- Sulfur dioxide (SO₂)
- Nitrogen dioxide (NO₂)
AQI Levels & Health Impact
Understanding each AQI level and what it means for your health
Health Effects of Air Pollution
How different AQI levels affect your health, especially for sensitive groups
Respiratory Effects
Air pollution can cause coughing, throat irritation, chest pain, and breathing difficulties. Long-term exposure may lead to reduced lung function.
Cardiovascular Impact
Poor air quality can increase the risk of heart attacks, strokes, and irregular heartbeat, especially in people with existing heart conditions.
Effects on Children
Children are more vulnerable to air pollution. It can affect lung development, increase asthma attacks, and cause respiratory infections.
Impact on Elderly
Older adults face higher risks from air pollution, including increased hospitalizations and premature death from heart and lung diseases.
Sensitive Groups
People with asthma, COPD, heart disease, or diabetes are more susceptible to air pollution effects at lower AQI levels.
Exercise Impact
Physical activity increases breathing rate, causing you to inhale more pollutants. Adjust outdoor exercise based on AQI levels.
How to Protect Yourself
Practical steps to reduce your exposure to air pollution
Daily Protection Strategies
- Check AQI forecasts before planning outdoor activities
- Limit outdoor exercise when AQI is above 100
- Use air purifiers with HEPA filters indoors
- Keep windows closed during high pollution days
- Wear N95 masks when AQI exceeds 150
- Create a clean air room in your home
- Avoid busy roads and traffic during peak hours
- Use public transportation or electric vehicles when possible
Indoor Air Quality Tips
- Avoid smoking and secondhand smoke indoors
- Use exhaust fans when cooking
- Keep houseplants that help purify air
- Regular HVAC maintenance and filter changes
- Minimize use of candles and air fresheners
- Control humidity levels (30-50%)
- Vacuum regularly with HEPA filter
- Seal cracks and openings to prevent outdoor pollution entry
Quick Reference Guide
At-a-glance recommendations for different AQI levels
| AQI Level | Outdoor Exercise | Sensitive Groups | General Population | Mask Recommendation |
|---|---|---|---|---|
| 0-50 (Good) | Normal activity | Normal activity | Normal activity | Not needed |
| 51-100 (Moderate) | Normal activity | Consider reducing prolonged exposure | Normal activity | Not needed |
| 101-150 (Unhealthy for Sensitive) | Reduce prolonged/heavy exercise | Avoid prolonged outdoor activities | Limit prolonged outdoor exertion | Consider for sensitive groups |
| 151-200 (Unhealthy) | Avoid heavy outdoor exercise | Avoid outdoor activities | Limit outdoor activities | N95 recommended |
| 201-300 (Very Unhealthy) | Cancel outdoor exercise | Stay indoors | Avoid outdoor activities | N95 required outdoors |
| 301+ (Hazardous) | Stay indoors | Stay indoors, seal windows | Stay indoors | N95 required if must go out |
Check Your Local Air Quality
Stay informed about your area's air quality and make healthier decisions for you and your family.
Check AQI Near Me