Level of Concern
Index Values
Air quality is satisfactory, and air pollution poses little or no risk.
Air quality is acceptable. However, there may be a risk for some people, particularly
those 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 less
likely to be affected.
Some members of the general public may experience health effects; members of sensitive
groups may experience more serious health effects.
Health alert: The risk of health effects is increased for everyone.
Health warning of emergency conditions: everyone is more likely to be affected.
