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EPA announces new review of ozone standard

The move delays possibility of tightening regulations

by Krystal Vasquez
August 25, 2023 | A version of this story appeared in Volume 101, Issue 28

View of downtown Los Angeles obscured by smog.
Credit: mikeledray/Shutterstock
Ozone is a major component of smog, which is a common sight in cities like Los Angeles.

The US Environmental Protection Agency is launching a new review of the Ozone National Ambient Air Quality Standards, delaying the possibility of tighter regulations on the smog-forming pollutant.

EPA administrator Michael Regan says he made the decision after reviewing comments provided by the Clean Air Scientific Advisory Committee (CASAC) on a preliminary version of the agency’s revised policy assessment of ozone. The committee is an independent body that advises the EPA on national ambient air quality standards.

“It is clear that CASAC’s careful review has identified several issues arising in the [assessment] that warrant additional evaluation and review,” Regan writes in a letter addressed to the advisory panel. “In particular, I have taken note of the CASAC advice that the draft policy assessment is missing important analyses and information.”

Regan’s decision spurred immediate backlash from environmental and public health groups. “The EPA’s decision comes despite mounting evidence of the adverse health impacts and environmental damage caused by ozone pollution,” the environmental law group Earthjustice says in a press release.

Ozone, which is formed in the atmosphere through chemical reactions involving human-made pollutants, can lead to a slew of health problems, including chest pain and lung inflammation. Prolonged exposure to ozone has also been linked to an increased risk of premature death.

“The public will now have to wait for years for the chance of a stronger national limit on ozone, suffering health harms in the meantime,” American Lung Association CEO Harold Wimmer says in a statement.

In addition to pointing out flaws in the EPA’s ozone assessment, the CASAC panel recommended that the agency lower the standard to between 55 and 60 parts per billion, from 70 ppb today.

Regan did not provide a timeline for the new review to be carried out. However, under the Clean Air Act, the EPA is legally obligated to complete its review of the ozone standards by December 2025.



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