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Ozone Health Advisory Program Summaries

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2009 Ozone Health Advisory Program Summary (4/1/09–10/31/09)

National Park Service Area*

Number of Days
8-hr Ozone
Average > 75 ppb

Number of Days Ozone Health Advisory Issued

Acadia NP 2 3
Great Smoky Mtns NP 1 0
Mammoth Cave NP 0 0
Pinnacles NP 0 1
Rocky Mountain NP 0 1
Sequoia & Kings Canyon NPs 72 39
Shenandoah NP 0 0
Yosemite NP 9 1
* This table shows the results for NPS areas participating in the 2009 ozone health advisory program.
† Ozone values above 75 part per billion (ppb) exceed the ozone National Ambient Air Quality Standard.
‡ Health advisories issued by the National Park Service area were based on State and local advisory forecasts. However, the measured ozone concentration in the Park may not have exceeded the 8-hr average ozone standard on the day of the advisory.

The 8-hour ozone health standard can be exceeded anytime during a 24-hour day time period. Ozone health advisories are initiated during the daylight hours, therefore, the ozone health standard can be exceeded at an area and an ozone health advisory not be issued.

Yosemite NP – there was one day when the National Park Service issued an ozone health advisory at the park. On that day when the ozone health advisory was issued there was also a health advisory issued for particulate matter (less than 2.5 microns).  There were an additional six days when health advisories were issued for fine particulate matter (less than 2.5 microns) conditions only.

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Last Updated: April 02, 2012