A Flawed Process and a Harmful Outcome: My Comments on the EPA Particulate Pollution Standards

May 20, 2020 | 8:00 am
Gretchen Goldman
Former Contributor

On Thursday, May 21, I will deliver the below oral comments to the US Environmental Protection Agency, speaking against Administrator Wheeler’s proposed rule to maintain the current National Ambient Air Quality Standards (NAAQS) for particulate matter (PM).


Thank you for the opportunity to comment. I am the Research Director in the Center for Science and Democracy at the Union of Concerned Scientists. On behalf of more than half a million scientists and supporters, we advocate for the use of science for a healthy planet and a safer world.

“The EPA’s draft rule on the PM NAAQS is fundamentally flawed. This rule was developed through an illegitimate process, fails to follow the best available science advice, and fails to adequately protect public health.

First, the process was doomed from the start. The EPA failed to conduct a PM NAAQS review that would have led to a science-based proposal. The administration disbanded the Particulate Matter Review Panelremoved independent scientists from the Clean Air Scientific Advisory Committee, eliminated drafts of scientific documents, cut out public comment opportunities, and recklessly expedited the entire review. As a consequence, this draft rule has not received the level of scientific review and public input that such an impactful rule warrants.

Notably, the administrator even ignored CASAC when the Committee formally acknowledged that it didn’t have the expertise to conduct an adequate scientific review. In the end, CASAC failed to reach consensus on the primary annual standard for PM2.5. And yet, despite this split advice and despite the committee’s own recognition of its inadequacy, Administrator Wheeler relies on CASAC as its sole backing of science advice for this ill-conceived rule.

Because this rule followed an illegitimate process with insufficient scientific review, the Administrator should abandon it. If the agency wants to ensure science-based and health-protective standards, the EPA should go back to the drawing board. However, if the administration insists on moving forward in this flawed process, the only scientifically defensible option is to heed the recommendations of the Independent Particulate Matter Review Panel.

Despite being disbanded by the Trump administration, the 20-member panel of top experts in particulate matter and health and welfare effects did its job anyway and assessed the science and policy options informing the standards. Of note, the panel contains more experts, more experience and more depth, breadth, and diversity of expertise relevant to the PM NAAQS review than the remaining seven-member CASAC informing the standards.

In its final report to Administrator Wheeler, the panel concludes that the current particulate matter standards are not adequate to protect public health with an adequate margin of safety, as the Clean Air Act requires. On PM2.5, the panel found that new and consistent epidemiological findings, supported by human and animal studies and other studies with natural experiments, provide “clear and compelling scientific evidence” for tighter standards. Since the last particulate matter review, several new large-scale epidemiologic studies provide powerful evidence that particulate matter is causing adverse health outcomes, including early death, heart attacks, and respiratory stress, at locations and during time periods with concentrations at or below the level of the current standards.

The administrator, on the other hand, ignores this new evidence of health effects below the current PM2.5 standards and provides no justification for why it does not find this new scientific evidence compelling. It is indeed a policy judgement of where to set the standards, but the Clean Air Act requires the administrator to include an adequate margin of safety for at-risk groups. Given the evidence and the advice of the Independent Panel, it is clear that the administration is not interested in protecting these groups.

Inexplicably, the administrator notes the lack of accountability studies as a reason to ignore the epidemiologic evidence that the panel found compelling.  Such an argument is is questionable because it is unethical and illegal in many study designs to expose study subjects, such as children or the elderly, to harmful levels of air pollution. Thus, it is unreasonable to expect clinical evidence of harm in the manner that would be necessary to meet the administrator’s criteria as laid out in the rule justification.

By ignoring the Independent Particulate Matter Review Panel, and the scientific community at large, the administration is putting the public at risk. I urge Administrator Wheeler to abandon this ill-conceived and dangerous proposal.”

Join me in asking Administrator Wheeler to set particulate matter standards that protect public health. Submit your own written comment to the EPA by June 29.