Good |
0 to 50 |
Air quality is considered satisfactory, and air pollution
poses little or no risk |
Moderate |
51 to 100 |
Air quality is acceptable; however, for some pollutants
there may be a moderate health concern for a very small number of people who are unusually
sensitive to air pollution. |
Unhealthy for Sensitive
Groups |
101 to 150 |
Members of sensitive groups may experience
health effects. The general public is not likely to be affected. |
Unhealthy |
151 to 200 |
Everyone may begin to experience health
effects; members
of sensitive groups may experience more serious health effects. |
Very Unhealthy |
201 to 300 |
Health warnings of emergency conditions. The
entire
population is more likely to be affected. |
Hazardous |
301 to 500 |
Health alert: everyone may experience more
serious health effects. |