Changes to Ozone and Fine PM Standards
EPA established a tighter ozone standard in the spring of 2008 to better protect public health. The AQI for ozone has also been revised to reflect this change. More information on the new ozone standard and AQI is at: http://www.epa.gov/groundlevelozone/actions.html.
 
The AQI for the new fine PM standard has not yet been officially revised, but EPA is changing the moderate to unhealthy for sensitive groups transition from an AQI of 40.5 to 35.5. More information on the new PM standard is at: http://www.epa.gov/air/particlepollution/standards.html.
March 2008

Archived "What's New" Items