Air pollution researchers and public health experts on Dec. 12 publicly urged the U.S. Environmental Protection Agency to reconstitute a recently disbanded panel tasked with helping the agency’s Clean Air Scientific Advisory Committee, or CASAC, review the health impacts of tiny airborne particles.
Chartered under the Clean Air Act, the CASAC's role is to aid the EPA administrator in reviewing and deciding whether to revise or maintain the National Ambient Air Quality Standards, or NAAQS, for six different pollutants, including fine particulate matter, every five years. Emissions from fossil fuel-fired power plants, industrial facilities and vehicles are the largest sources of fine particulate matter that measure 2.5 micrometers or less, which is also known as PM 2.5. Tightening the NAAQS can require industry to install costly pollution controls, but it can also generate billions of dollars in public health benefits.
A growing body of research has shown a causal link between PM 2.5 — which can make its way from ambient air through the lungs and into the heart and brain — and respiratory health problems, as well as premature death. Based on a lengthy scientific review, the EPA in 2012 strengthened the annual standard for PM 2.5 to 12 micrograms per cubic meter, down from the previous standard of 15 micrograms per cubic meter. The decision was supported by the agency's Integrated Science Assessment, a 1,000-page research document covering the most recent scientific findings on PM 2.5 at the time.
Since its creation, the seven-member CASAC has traditionally relied on outside advisory panels of dozens of scientists with expertise across multiple research disciplines to ensure thorough NAAQS reviews. However, former EPA Administrator Scott Pruitt set the stage for dramatic changes to the NAAQS review process by issuing a "back-to-basics" memo in May that outlined an expedited review of particulate matter and ozone, which are both scheduled to conclude in late 2020.
A few months later, EPA Acting Administrator Andrew Wheeler sparked an outcry within the scientific community when on Oct. 11 he disbanded a 20-person panel of particulate matter experts and dissolved a similar advisory panel on ozone pollution. At the same time, Wheeler installed five new members to the CASAC. The committee is now entirely comprised of Trump administration appointees following a new policy introduced by Pruitt that bars recipients of agency grant money from serving as advisers.
In justifying the dissolution of the advisory panels, Wheeler said the move was consistent with the CASAC's charter and plain language of the Clean Air Act.
The committee's new chair, Tony Cox, has drawn increased scrutiny for past comments suggesting large reductions in ozone levels have caused "no detectable public health benefits." Cox, the president of a Denver-based applied research company, has also conducted research for clients that include the American Petroleum Institute, the American Chemistry Council and the European petroleum consortium CONCAWE.
Days before a Dec. 12 meeting to review the nearly 1,900-page draft of the EPA's latest Integrated Science Assessment on particulate matter, 15 members of the recently disbanded particulate matter panel — including two former CASAC chairs — sent a 134-page letter addressed to Cox. The group expressed dismay with the changes to the NAAQS review process and asserted that the current seven-member CASAC "does not have the depth or breadth of expertise needed for the particulate matter review, nor could any group of this size cover the needed scientific disciplines."
During the Dec. 12 meeting at a hotel in Arlington, Va., Cox pressed EPA staff on the contents of the draft document, seeking to clarify whether the studies in the document show a direct or indirect link between PM 2.5 exposure and health problems. "Are these fact-focused, causal relationships, or likely to be causal relationships?" Cox asked. "Are these definitive?" EPA staff responded that the agency does not focus on individual studies, but rather considers the full weight of the body of scientific evidence in determining the NAAQS for pollutants such as PM 2.5.
The findings of the Integrated Science Assessment provide more evidence that long-term exposure to PM 2.5 causes premature death. The document also offers more detailed information about the levels of exposure at which PM 2.5 has measurable health effects, which some studies have shown is even lower than the current standard. And the assessment offers a stronger finding from the previous review that exposure to fine particles is likely to cause cancer.
Researchers and air pollution experts repeatedly during the Dec. 12 meeting lamented the move to disband the particulate matter panel. “You should ask yourselves, do we have the necessary expertise in all of the most critical science disciplines to do this review?" said Chris Frey, an air pollution expert at North Carolina State University who served as CASAC chair from 2012 to 2015. "And clearly the answer is no.” Frey, who signed the letter to Cox, reiterated the former panel members' advice to reinstate advisory panels for both particulate matter and ozone.
Mark Frampton, a newly appointed CASAC member and pulmonologist at the University of Rochester Medical Center, suggested that the committee needed to identify the gaps in its expertise before proceeding with the review. Cox, however, said the committee would revisit process issues at a later time.
"The EPA and CASAC welcome public comments throughout the ozone and particulate matter review process," EPA spokesman Michael Abboud said Dec. 12 in an email. He also noted that Wheeler can add more consultants to provide relevant expertise to the CASAC "if deemed necessary."
In November, Senate Democrats demanded information and documents from the EPA related to the appointment of new members to the CASAC and dismissal of the two advisory panels. "These actions, taken together with past similar actions, could have the effect of jeopardizing the environment and human health, because they are likely to result in the replacement of renowned scientists who can provide EPA with advice on how to best protect people from the effects of environmental pollution with less qualified, industry representatives who may also have conflicts of interest," the senators said.
Rep. Frank Pallone, D-N.J., who will chair the House Energy and Commerce Committee in the 116th Congress, said in an email he was also troubled by the changes to the NAAQS review. "I am deeply concerned by this unprecedented action to limit scientific review in support of protecting public health under the Clean Air Act," he said. "As the committee of jurisdiction, we will be conducting robust oversight over EPA in the new Congress."