Dive Brief:

• The U.S. Court of Appeals for the District of Columbia Circuit Tuesday upheld the Environmental Protection Agency's broad efforts to regulate ground-level ozone pollution, The Hill reports. 
• In its 87-page opinion, the D.C. Circuit rejected multiple challenges from states and fossil fuel interests that argued the EPA had acted arbitrarily and capriciously in writing and implementing ozone regulations finalized under President Bush in 2008. All states that the EPA designates as being in "nonattainment" with the regulations must work to reduce ground-level ozone, a byproduct of fossil fuel burning, the court said.
• EPA officials welcomed the decision, which could bouy the agency's planned efforts for later this year to further restrict ozone levels.

Dive Insight:

Ground level ozone forms when chemicals in common fossil fuel emissions react with sunlight and the air to form ozone, or smog. While ozone is essential in the upper atmosphere to protect the Earth from ultraviolet rays, at ground level the American Lung Association warns that it can cause shortness of breath, inflammation of lung tissue, asthma attacks, and premature death, especially among children, the elderly, and those with reduced lung functions. 

In 2008, when the EPA set the ozone standard at 75 parts per billion (ppb), it estimated that the standard could prevent thousands of premature deaths and tens of thousands of respiratory diseases, asthma attacks, and heart attacks. In an effort to enhance those health benefits, the EPA has proposed tightening that standard to between 65 and 70 ppb, the level that the Bush administration's EPA staff originally suggested for the rule, but was never enacted.

The regulations don't sit well with fossil fuel generators and many state governments, which have called them the most expensive ever. A number of different legal suits, led by complaints from Delaware and Connecticut, alleged that the EPA did not properly consider the costs of the regulation. They were combined by the D.C. Circuit, and then dismissed. 

"Virtually every petitioner argues that, for one reason or another, the EPA acted arbitrarily and capriciously in making its final ... designations," the decision reads. "But because the EPA complied with the Constitution, reasonably interpreted the [Clean Air Act’s] critical terms and wholly satisfied — indeed, in most instances, surpassed — its obligation to engage in reasoned decision-making, we deny the consolidated petitions for review in their entirety."

EPA officials welcomed the decision from the nation's top federal appeals court, which could fortify the agency's legal standing to tighten ozone regulations this year. Those regulations were slated to be released in 2011, but were delayed by the White House until after the 2012 election campaign.