EPA’s ozone do-over faces backlash

By Sean Reilly | 08/22/2023 01:31 PM EDT

“I am disappointed, given the robust scientific evidence that ozone is harmful to public health and welfare,” said Lianne Sheppard, who heads an EPA expert advisory panel.

A traffic sign warns of an ozone alert.

A traffic sign warns of an ozone alert on July 23, 2021, in Denver. EPA has announced plans to restart its review of ozone standards. David Zalubowski/AP Photo

Twelve years ago, environmental and public health groups seethed as then-President Barack Obama shut down plans to tighten EPA air quality standards for ground-level ozone.

On Monday, they watched in dismay as a similar scenario unfolded under another Democratic president.

Two months after an EPA expert advisory panel recommended steep cuts on the limits of the lung-searing pollutant, agency Administrator Michael Regan said that he was instead launching a fresh assessment of the standards that will likely take years to complete.


Because of scientific issues flagged by the panel warranting “additional evaluation,” Regan wrote in a letter released Monday, “I have decided that the best path forward is to initiate a new statutory review.”

His punt means that President Joe Biden’s administration will be spared a divisive decision on tightening one of EPA’s most important air quality regulations in advance of next year’s elections.

Asked in an email Monday evening whether the White House had any involvement, a spokesperson did not reply by publication time Tuesday. At EPA, agency spokesperson Khanya Brann did not address a similar question but said in an email that “EPA’s process is independent, transparent, and science based.”

Meanwhile, John Bachmann, a former senior EPA air office employee who worked on past reviews of pollutant standards, said that there is a valid argument for a do-over, though a host of advocacy organizations predicted that human health will suffer in the interim.

“This means tens of millions of Americans will be subject to unsafe air pollution for years to come,” John Walke, clean air director for the Natural Resources Defense Council, said in a statement. “The EPA has had four years to get this done,” Walke added, “and the agency must commit to finalize this review” by a Clean Air Act deadline of December 2025.

Lianne Sheppard, a University of Washington biostatistics professor who chairs the EPA panel, formally known as the Clean Air Scientific Advisory Committee, said in a Tuesday email that she respected Regan’s decision, “which is his alone to make.”

“However, I am disappointed, given the robust scientific evidence that ozone is harmful to public health and welfare,” Sheppard continued, adding that she was confident that EPA can meet the 2025 deadline.

Regan’s decision also bucks recent urgings by the White House Environmental Justice Advisory Council and a coalition of Democratic lawmakers, both of which had separately called for adoption of a new ozone standard by the spring of next year.

In an interview, Bachmann, however, noted that any tightening of the current limit would inevitably be challenged in court. EPA, he said, “needed the support” of a better scientific basis for coming to that conclusion. Given the risk of a legal setback, Bachmann said, “why not just do it right?”

The new review will build on work already done; in his letter, Regan said he had told EPA employees to complete it “as expeditiously as possible.” But while agency officials did not release a full timetable Monday, they intend to provide a revised master plan only in the fall of 2024, meaning that a series of steps — including an updated roundup of the scientific research into ozone’s health and environmental effects — would still have to follow. Based on the course of earlier reviews of air quality standards for various pollutants, the final outcome could be years off.

Should a Republican win the presidency in November 2024, the lag time could be even longer.

Ozone, a toxic gas and the main ingredient in smog, is tied to asthma attacks in children and worsened breathing ability in adults with emphysema and other chronic respiratory diseases. It’s spawned by a combination of pollutants closely tied to the production and consumption of fossil fuels. Any tightening of EPA’s air quality standards can therefore ripple across a broad swath of the economy.

In 2011, Obama infuriated green groups by squelching a reappraisal of what was then an ozone limit of 75 parts per billion even as EPA was seeking to tighten it. At the time, Obama cited a desire to reduce regulatory burdens and regulatory uncertainty; critics said he was more concerned about the potential impact on his 2012 reelection prospects.

Four years passed before EPA in 2015 finally strengthened the limit to 70 ppb, which remains in effect today. In a June report to Regan, six of the seven members of the Clean Air Scientific Advisory Committee recommended strengthening it to between 60 and 55 ppb.

Like other regulatory conundrums facing EPA, this can be traced back to former President Donald Trump’s tenure. Under the Clean Air Act, EPA is supposed to revisit the standards for ozone and other key pollutants every five years based on the latest scientific research into their effects. In practice, the agency has rarely met that schedule, but in mid-2018, the Trump-era EPA abruptly launched a new review of the ozone standards on the grounds that the law required its completion by 2020.

The ensuing rushed assessment ended in December 2020 with a finding that no change to the 70 ppb limit was warranted. Advocacy groups and Democratic state officeholders soon challenged that decision in court; in October 2021, Regan agreed to reconsider, with a goal of wrapping up the revised look by the end of this year.

As the reconsideration got underway, however, EPA relied on the same scientific research roundup used for the Trump administration review; Sheppard in May 2022 took the unusual step of pausing the CASAC’s work after noting that several members had raised concerns about the “causal determinations” on ozone’s effects made in that roundup.

The committee, made up mostly of academic researchers, did not resume its deliberations until last September. The majority’s eventual conclusions in favor of a significant cut to the 70 ppb standard also clashed with the findings of EPA career staff that the status quo remains adequate.

In his newly released reply to the committee’s June report, Regan wrote that the panel had also relied on recent studies not included in the earlier roundup. Its assessment, he added, had flagged several issues “that warrant additional evaluation and review, both by the EPA and by CASAC, including newly available information that has not yet been integrated into the air quality criteria and the value of developing additional analyses to inform further evaluation of the current standards.”