In June, the public comment period closed on the EPA’s draft rule on the National Ambient Air Quality Standards for Particulate Matter. Now we wait, as the agency reviews the more than 66,000 public comments submitted and Trump leadership at EPA rushes to finalize the rule by its own arbitrary deadline of the end of 2020. Here’s a rundown of the state of play, and where I and the Union of Concerned Scientists stand on the nation’s protections against one of the most common and harmful air pollutants in the US.
A broken process and a flawed result
It has been a wild ride. In many ways, the process was doomed from the start. Early in the Trump Administration, EPA leaders began meddling with science advisory committees and indicated they were going to expedite the process for reviewing the particulate matter and ozone standards for no legitimate reason. It was clear the administration had no intention of considering the science when in October 2018, it disbanded the Particulate Matter Review Panel, a group of nearly two dozen of the nation’s top experts on particulate matter and health and welfare effects. It was the same kind of all-star lineup of experts that had informed EPA’s ambient air pollutant standards since they began decades ago.
At the same time, EPA leaders gutted the seven-member Clean Air Scientific Advisory Committee and replaced its independent scientists, leaving only one academic scientist on a committee usually dominated by them and appointing an industry consultant with no experience as an EPA science advisor to lead the group.
The results were what you might expect. From its first meeting, it was clear the group was inadequate to advise the agency, and they knew it. To their credit, they told EPA they needed the Panel reinstated and that they didn’t have the adequate expertise to review the Particulate Matter Standards. But Administrator Wheeler didn’t listen, instead he made a half-hearted effort to throw some consultants into the process at the eleventh hour, presumably to create a façade of responsiveness to what was clearly a gaping hole in needed expertise.
In the end, the advisors—whose advice historically set the scientific basis for ambient air quality standards—couldn’t even come to agreement on the fundamental question of whether the current standards adequately protect public health and welfare, let alone provide a consensus range of standards backed by the scientific evidence.
Putting science back into the process…for it to be ignored
Meanwhile, the (now independent) Particulate Matter Review Panel met and advised the agency anyway, hosted by the Union of Concerned Scientists for an in-person meeting. The 20-person panel (which had more breadth, depth, and diversity of expertise on the particulate matter standards then the advisory committee, by a long shot) came to agreement that the standards were inadequate and recommended tighter standards for fine particulate matter, a pollutant that kills and sickens thousands in the US each year.
So what did EPA Administrator Wheeler do? Despite EPA staff and the Independent Particulate Matter Review Panel both concluding the standards need tightening, Wheeler instead chose to side with part of the seven-member Committee concluding that there is not sufficient evidence to justify tightening the standards, with only a vague commentary in the draft rule that essentially parrots the opinion of some CASAC members and barely delves into any scientific explanation for the decision.
The growing science of health effects of particulate matter
So where does the science lie? The science is always changing. That’s why the architects of the Clean Air Act mandated that the standards be revisited every five years to ensure they continue to protect public health. Since the Clean Air Act passed in 1970, this process has been remarkably successful, with air pollution levels dropping dramatically due in large part to this science-based law. Since the previous particulate matter standards update in 2012, more science now shows that fine particulate matter is harmful at lower levels. Several new epidemiologic studies show that even in places with average air quality at or below the current standards and in studies where those lower air pollution days are isolated, we still see evidence of health effects. Scientific evidence suggests there is no threshold below which fine particulate matter shows no health effects.
Because the science is changing so rapidly, and because the EPA review process takes many months, the agency typically updates discussion of the latest scientific studies at the end of the process to ensure that the rule is based on the latest science. This time, the EPA didn’t do that—and that choice is consequential. Several of the new studies showing harm at lower levels have emerged since EPA did its original literature review of the science. Thus, the advisory committee didn’t have the opportunity to review it. As a result, the draft rule hasn’t accounted for some of the latest and greatest science on particular matter and health effects.
Advocating for a science-based decision
The Union of Concerned Scientists has always advocated that the EPA follow science advice on the National Ambient Air Quality Standards. Historically, this meant advocating that the agency set ambient air quality standards within the range that CASAC recommended. But the current review of the particulate matter standards is atypical for all the reasons noted above. Given the flawed CASAC and the flawed process, and in light of the latest science showing compelling evidence of harm at levels below the current standards, it is clear that CASAC’s recommendations do not provide adequate science advice.
Instead, the EPA should follow the advice of the Independent Panel. It provided robust review of the science and policy considerations on particulate matter, even after the agency dismissed it. On the annual standard for fine particulate matter (PM2.5), the Panel recommended a range of 8-10 µg/m3. In light of new science released since the Panel met, the EPA should set the standard on the lower end of that range.
The reality is that the country should have gotten a thorough, science-based, and public-informed process to set national standards on a pollutant that causes sickness and early death in tens of thousands every year. But we didn’t. The Trump administration robbed us of that opportunity by gutting the process and removing key people that would have helped carry it out. We are now left with an imperfect process with which to make a decision that will affect the air we all breathe for years to come. If we don’t attempt to make a science-based decision now, we are set back years before we again have the opportunity to set standards that protect public health.
These are unprecedented times, and this was an unprecedented process. In the end, despite EPA leadership, the work was done to ensure a science-informed standard. All Administrator Wheeler needs to do is listen.
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