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EPA ozone hearing in Chicago Sept. 5

November 17, 2010

Proposed Environmental Protection Agency revisions to the primary and secondary national ambient air quality standards (NAAQS) for ground-level ozone, the primary component of smog, will be debated at a public hearing in Chicago, Atlanta and Houston Sept. 5.


The proposed revisions reflect new science about ozone and its effects on people and public welfare. A complete set of documents related to the proposal is 

The proposal would revise both of the EPA’s ozone standards—the primary standard, designed to protect human health; and the secondary standard, designed to protect welfare, like vegetation and crops. The existing primary and secondary standards, set in 1997, are identical.


The Clean Air Act requires the EPA to set NAAQS for pollutants considered harmful to public health and the environment. The agency seeks to incrementally reduce permissible ozone levels "to provide increased protection for children and other ‘at risk’ populations against an array of ozone-related adverse health effects that range from decreased lung function and increased respiratory symptoms to serious indicators of respiratory morbidity." 

"Good" ozone occurs naturally in the stratosphere approximately 10 to 30 miles above the earth’s surface and forms a layer that protects life on earth from the sun’s harmful rays. In the earth’s lower atmosphere, ground-level ozone is considered "bad."


Manmade and natural sources help create ozone by a chemical reaction between oxides of nitrogen and volatile organic compounds in the presence of sunlight. The Sept. 5 hearing is at the Westin Michigan Avenue Chicago, 909 N. Michigan Ave. Commenters can speak for five minutes each.