Module # and Title

Ozone - Status

nSources

•Formed in the atmosphere from precursors NOX and VOC

nEffects

•Respiratory stressor

•Crop and forest damage

nTrends

•U.S. average concentration down 20% over past 20 years

•40+ urban areas routinely exceed the 8-hr standard, many in the Mid-Atlantic U.S.

•Concentrations found to damage human health are set progressively lower

•