Five Takeaways from the EPA Meeting on Particulate Pollution

March 29, 2019 | 2:48 pm
Photo: Steven Buss/Flickr
Gretchen Goldman
Former Contributor

Yesterday, the EPA Clean Air Scientific Advisory Committee (CASAC) had a teleconference to discuss their recommendations to the administration on the agency’s assessment of the science on particulate matter (PM) and health. The meeting continued the ongoing push and pull between the EPA, its science advisors, and the committee chair Dr. Tony Cox.

The committee was meeting to finalize a letter they will jointly send to the EPA recommending changes to its draft science assessment on the state of particulates and health, a key document that informs the EPA’s (statutorily required to be science-based) decision on the level of particulate matter that protects public health. (More background and information on the state of play in my Scientific American piece here.) Here’s five top takeaways from the meeting:

1. CASAC admits it doesn’t have the needed expertise

The committee finally agreed on what was obvious to everyone else: They need more expertise. Since EPA leaders dismissed the particulate matter review panel last October and selected a new set of CASAC members that don’t include key expertise like epidemiology, it has been abundantly clear that the current seven-member CASAC is insufficient to review the hefty and wide-ranging scope of the EPA’s science assessment. I, and many other scientists, made this point in public comments at the December meeting. And a letter signed by 206 air quality in public health experts asked the administration to reinstate the panel. Members of CASAC themselves echoed these concerns but in December the chair pressed forward, ignoring them. This time, he conceded they needed more expertise and the group agreed to put language in their final letter that asks for a reconvening of the particulate matter review panel or one with comparable expertise, plus a few additional expertise areas they indicate needing.

This new consensus is important. The committee now has disagreed with EPA Administrator Andrew Wheeler who told Congress earlier this year that the panel had the needed expertise to conduct the review. In response to a question from Senator Carper asking about the dismissal of the PM panel, Administrator Wheeler said, “I believe the current CASAC has the experience and expertise needed to serve in this capacity as well as to complete the reviews for the particulate matter and ozone NAAQS.” The committee now admits they do not, raising questions about whether the EPA will be able to obtain the best available science advice necessary to set a science-based PM standard that protects public health, as the Clean Air Act requires.

2. CASAC members pushed back on the chair

While at the December meeting the Chair was able to override most disagreements raised by others, in this meeting CASAC members were more willing to speak up and disagree with the Chair on letter contents. As a result, many of the most damaging elements of the draft letter that the Chair released on March 7th were removed. The draft letter had uncharacteristically strong critiques for how the EPA conducted its science assessment calling the robustly lengthy and exhaustively referenced document “unverifiable opinion” and accusing the EPA of not following the scientific method. The committee has thankfully agreed to strike this language. It is less clear if committee members were able to push back on all of the problematic language in the letter, but the final draft should be substantially less hostile to EPA’s science assessment than the version Cox drafted.

3. The scientific community stood up

The broader scientific community is not sitting this one out. Last week I released a paper in Science with Harvard data scientist and air pollution and health effects expert Francesca Dominici. The paper took on Cox directly for his fringe ideas about how the EPA should approach assessing links between air pollution and health outcomes like early death and respiratory disease. Many other top experts in the field gave in-person comments or submitted written comments criticizing the process and scientific approach being taken by CASAC chair. There were also organizational comments from the Health Effects Institute and the International Society for Environmental Epidemiology, as well as a letter signed by 17 members of the dismissed PM review panel. These critical comments build on public comments submitted and delivered at CASAC’s December meeting, including comments from former CASAC members and former PM review panel members, and former ozone review panel members. In short, the top experts in air pollution and health are in strong unified opposition to the approach being taken by Dr. Cox and this meeting made that abundantly clear.

4. The chair has not moderated his fringe views

Dr. Cox was criticized in my Science piece and elsewhere for his views far outside the mainstream scientific community on air pollution and health. While Dr. Cox expressed surprise with this characterization, mentioning my Science piece explicitly, he did not moderate his views throughout the meeting, noting that he is “appalled” with the lack of evidence for the connection between particulate matter and early death, a relationship that scientists have studied and confirmed in many studies, over many years, in many locations around the world, using different study designs.

5. The process is broken

The (well-designed, in my opinion) process for developing air pollution standards is now broken for this PM standard update. This started long before the current CASAC was appointed. Last spring in his “Back to Basics” memo, former EPA Administrator Pruitt made clear he intended to expedite the process for updating the particulate matter and ozone standards and create conditions that made it harder for robust science advice to inform National Ambient Air Quality Standards. Pruitt and now Administrator Wheeler made good on that promise by tearing down the scientific supports that ensure a robust scientific process with ample opportunities for public input.

EPA is now in a tough spot. It would be difficult in any event to complete a PM review by 2020 as the administration intends. Doing so was made more difficult by the administration nixing the PM review panel. It is now made even more difficult by CASAC’s intention to ask for the panel to be reinstated, a move that would surely mean more public meetings, document drafts, and a general delay in the process.

Alternatively, the administration could move forward, ignoring CASAC’s request for more expertise but in doing so, they are almost certainly setting themselves up for legal challenges. If CASAC itself acknowledges they don’t have the scientific expertise to conduct a science-based review, how can the administration claim to have set a science-based standard? Based on yesterday’s discussion, there are likely to be some elements of the final letter that still conflict with the broader scientific community’s opinion on EPA’s approach, despite pushback from several committee members and nearly all public comments. We will see what the final letter to the administration from CASAC looks like, but one thing is for certain, this process is broken.


My written comments from the meeting are here and below are my oral comments and clarifying comments made at the meeting yesterday.


Oral Comments Delivered at the March 28, 2019 CASAC Teleconference:

Thank you for the opportunity to comment. I am the research director at the Center for Science and Democracy at the Union of Concerned Scientists. On behalf of more than half a million citizens and scientists, we advocate for the use of science for a healthy planet and a safer world. The Center for Science and Democracy works to advance the roles of science and public participation in policy decision-making. We have never advocated for an ambient air quality standard different from the CASAC recommendation, only to ensure the proper process is followed and scientific advice is heeded.

The Clean Air Act requires that the EPA set particulate matter (PM) standards at levels that protect public health and welfare with an adequate margin of safety. CASAC is charged with considering all available evidence and providing science advice on the standards. At this stage in the PM standard update, there are significant challenges to both the science and process that CASAC is following. 

Scientific Issues

The ISA deserves to be scrutinized and improved by experts on all facets of the assessment. And CASAC’s review of the ISA should be helping EPA to identify new research questions and to refine its characterization of the state of the science. However, this has not been the case.

It is crucial that CASAC rely on the wealth of knowledge in the published literature, as reflected in the ISA draft. CASAC should rely on the established approach for assessing the causal links between particulate pollution and health impacts, as detailed in the preamble to the ISAs.  The causal framework employed by the EPA has evolved over the past decade, has been endorsed by 11 prior CASACs and 138 experts, and has been deemed adequate in the courts.

Yet, the March 7 draft letter by the CASAC chair proposes upending this scientifically backed and time-tested approach. The chair’s proposal would create an unattainable burden of proof on the scientific community to demonstrated causal links between PM reductions and changes in health outcomes, as it is not feasible or ethical to design and carry out population-level manipulative causation studies. 

Importantly, following the chair’s proposal is incompatible with CASAC’s charge to recommend PM standards that protect public health with an adequate margin of safety including sensitive subpopulations. Protecting groups such as the elderly, children, and those with lung diseases, with an adequate margin of safety requires the EPA to consider all evidence and use expert judgement. Relying on a framework that discounts epidemiologic evidence and requires manipulative causation for all causal determinations made by the agency is unlikely to meet this Clean Air Act mandate.

Process Issues

A flawed process produces a flawed result. Thus far, CASAC has not followed a process that is likely to lead to a science-based recommendation to the EPA Administrator. Significant gaps in expertise remain, given EPA leadership’s choice of CASAC members and the dismissal of the PM review panel.

Despite persistent calls for additional expertise by CASAC members, echoed by public comments, the CASAC chair has continued to press forward without addressing these concerns. As a result, the PM NAAQS review is proceeding without the science advice needed to ensure a health-protective standard.

This lack of expertise has been abundantly clear in CASAC meeting discussion and written comments from CASAC members. Rather than discussing key areas of uncertainty and the implications of new important research on particulate matter and health, as would be most helpful for the EPA to hear in deliberations from its top science advisors, CASAC instead has spent its valuable time within an expedited review process questioning and renegotiating well-established concepts, such as the value of the field of epidemiology, the importance of studying effects on at risk populations, and the connection between particulate exposure and premature death.

The proposed changes to EPA’s causal framework, expedited time frame, planned merging of documents, combined with gaps in expertise and limited public input opportunities—together—are likely to undermine the ability of the EPA to set a science-based standard for particulate matter, protective of public health.

Following the chair’s proposal and agreeing to these other changes prevents the EPA from relying on the best available science. I urge the members of CASAC and the EPA to listen to the recommendations of top experts in the scientific community and reject this proposal.


Clarifying comments made in response to CASAC Discussion:

On the discussion of two views of science, it seems there is conflation of individual studies and a review of existing studies. CASAC’s charge with respect to the ISA is to look at the body of evidence and the strength of the evidence. It is not CASAC’s job to decide how the broader scientific community should approach individual study designs. There is a time and place for that. It is not in the midst of an established EPA regulatory process. I’d like the committee to ask EPA staff for their perspective on this point and how EPA does approach a systematic review of the literature.

With respect to the discussion of the alternative framework proposed by the chair, I’d like to clarify that in the Science piece, we referenced and reacted to the Chair’s own words as presented in the draft letter under discussion as well as in the December meeting. The proposal would indeed reject most of the key studies EPA relies on for a causal assessment on long-term exposure to PM and mortality, a link that the chair has stated he is questioning. This is what Francesca Dominici and I, along with several other commenters are expressing concern about.

I would very much welcome the featuring of accountability studies and discussing them to the extent that they are informative to the ISA. I agree it is useful to have testable rules. But we cannot overrely on them in a context where we are using observational data to study an environmental risk. Instead of allowing these ideas to be introduced, debated, peer reviewed, and advanced in the scientific literature, the proposal suggests that this process be largely skipped and force fit into the EPA process when as we’ve heard several times today, this is not ready for prime time.

Lastly, the address the true versus estimated exposure conversation, true exposure is not knowable. Much work in the scientific literature, including my own, have characterized this issue in depth. The premise of what we are looking at is what is knowable. The Chair is calling this estimated but it is in fact the relevant value because the measure that is germane to improving an ambient standard is the “regulatory ambient” i.e. the relationship between ambient concentrations and health outcomes. There is no reason to complicate this with an explanation of the obvious fact that studies are using estimates.

Given the substantive changes to the letter being discussed, it seems another public call is warranted to ensure CASAC members have time to review and approve of the revised letter, also keeping in mind FACA rules on transparency of committee deliberations.