II. Definition
- Environmental Protection Agency (EPA) has >1000 air quality monitoring stations around U.S.
- EPA reports the Air Quality Index for a given day
- Based on the highest individual pollutant levels for a given monitoring station
- Pollutants monitored include
- Ground-Level Ozone (O3)
- Particulate matter
- Carbon Monoxide (CO)
- Nitrogen Dioxide (NO2)
- Sulfur Dioxide (SO2)
- Lead
- Each pollutant is assigned a maximal level above which it is unsafe
- Known as National Ambient Air Quality Standards (NAAQS)
- Air Quality Index values represent the pollutants percentage of the NAAQS unsafe level value
- Example, if ozone has a NAAQS of 0.075 ppm averaged over 8 hours
III. Interpretation
- Air Quality Index 0-50: Good
- Air Quality Index 51-100: Moderate
- Affects very sensitive people to either ozone or particulate matter
- Those at risk should avoid prolonged exposure or heavy exertion outdoors
- Air Quality Index 101-150: Unhealthy for sensitive groups
- High risk groups should avoid prolonged exposure or heavy exertion outdoors
- High risk groups
- Lung disease
- Heart disease (limit exposure if high particulate matter exposure)
- Children and young adults
- Athletes and other people with heavy outdoor exertion
- Air Quality Index 151-200: Unhealthy
- Everyone should avoid prolonged exposure or heavy exertion outdoors
- Air Quality Index >201: Very unhealthy
- Everyone should limit exposure and any exertion outdoors
IV. Complications: Increased Air Quality Index (AQI)
- Increased all cause mortality
- Increased Asthma Exacerbations
V. Resources
- EPA AirNow