Press Release Aug 23, 2019

Smog Standard Too Weak to Protect Parks and Forests, Court Rules

Court Upholds Health Standard, Rejects Polluters’ Claims That Standards Are Too Protective

WASHINGTON -– Today, the U.S. Court of Appeals for the District of Columbia Circuit said that the current national ambient air quality standards for ozone are too weak to protect the environment. The U.S. Environmental Protection Agency will now have to set standards that actually protect forests, as the Clean Air Act requires.

“The Clean Air Act requires EPA to set standards that protect forests against damage from smog. EPA didn’t do that here. It must go back and fix its mistakes so cherished natural spaces like national parks can thrive,” said Seth Johnson, the Earthjustice attorney who argued the case. “Unfortunately, the Court also said the ozone rules we have are enough to protect public health, even though these standards allow levels of smog EPA agrees are harmful. But this isn’t the end of the road. We’ll keep fighting for this vital health protection to be as effective as it needs to be.”

“Today’s court decision is a win for the future of our national parks and the millions of people who visit these treasured places every year,” said Stephanie Kodish, Clean Air Program Director for the National Parks Conservation Association. “Now, EPA must revisit the welfare standard to better protect our parks and their plants from air pollution like the 37 ozone-sensitive species of trees and plants at Great Smoky Mountains National Park and the iconic Quaking Aspen tree at Rocky Mountain National Park. We commend the court for holding EPA accountable to its mission to protect the environment.”

The Court’s opinion is nuanced and especially important now. The ruling requires EPA to follow the science and to make the tough decisions necessary to protect forests and natural landscapes from ozone damage to plant leaves and to growing trees. The court also entirely rejected polluters’ arguments that the standards provide too much protection. Agreeing with health and environmental advocates, the court ruled that “the Clean Air Act prohibits EPA” from weakening public health and welfare protections based on other considerations, as polluters and their allies have been urging EPA to do.

Unfortunately, the court also ruled that the health standards as they are meet the legal requirements to protect public health. Based on the most recent science, advocates believe the ozone standards are not stringent enough. Meanwhile, the American Lung Association’s State of the Air 2019 report finds that ozone pollution worsened over past years, as EPA has begun its review of the smog standards. A recent study found that exposure to ambient air pollutants, including ozone, was correlated with increased risk and progression of emphysema, even among non-smokers. The Trump/Wheeler EPA is known for dismissing science to weaken public health and environmental protections, but this decision confirms that the administration cannot legally do that in its forthcoming review.

While ozone is good as a protective layer in the stratosphere, ground-level ozone causes asthma attacks and other respiratory problems that can keep kids from school and adults from work. It can send kids and adults to the hospital, too, and is linked to premature death. It also damages plants and forests, stunting tree and crop growth. Formed by emissions from cars, trucks and factories, ozone is also a corrosive greenhouse gas. According to a recent report by the American Lung Association, more than 134.0 million people live in 197 counties that earned an F for ozone.

EPA estimates that, by 2025, the current 2015 standard will save hundreds of lives, prevent 230,000 asthma attacks in children, and prevent 160,000 missed school days for kids each year. However, leading medical societies have found that an even more protective standard is needed to safeguard families, particularly children and seniors, from preventable illness.

In October 2015, following litigation by health and environmental groups for missing the legally required deadline to review the ozone standard, EPA established a slightly more protective standard further limiting the amount of smog allowed in the air people breathe. The standard was strengthened from 75 parts per billion, established by the Bush administration, to 70 ppb.

The Court’s decision results from a suit brought by Earthjustice on behalf of the Sierra Club, Physicians for Social Responsibility, National Parks Conservation Association, Appalachian Mountain Club, and WE ACT for Environmental Justice. In the case decided today, Earthjustice also represented the American Lung Association and the Natural Resources Defense Council.

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About the National Parks Conservation Association: For 100 years, the nonpartisan National Parks Conservation Association has been the leading voice in safeguarding our national parks. NPCA and its more than 1.3 million members and supporters work together to protect and preserve our nation’s most iconic and inspirational places for future generations. For more information, visit

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