Scientists to EPA: Stop Sidelining Science in the Air Pollution Standard Update for Particulate Matter

December 10, 2018 | 11:07 pm
Gretchen Goldman
Former Contributor

More than 200 air quality and public health experts have penned a letter expressing concern about the limited scientific input into an air pollutant standard update. The 206 scientists are deeply troubled by recent actions of the EPA on its update to the health-based standard for particulate matter, a pollutant comprised of tiny solid particles that has been linked to respiratory and cardiovascular effects and early death.

The EPA recently dismissed its particulate matter review panel, a group of experts who have provided vital input into EPA’s particulate standard updates since they began more than a decade ago. Addressed to Acting EPA Administrator Andrew Wheeler, the experts write, “As professional scientists and engineers, we strongly object to sidelining science in this decisionmaking process. We strongly urge you to reinstate the Particulate Matter Review Panel to provide the Clean Air Scientific Advisory Committee, as well as your agency, with the best-possible scientific understanding.”

“Science is an objective search for truth.  When it is used to protect public health, it benefits everyone. When science is ignored, it is the public that is harmed,” said Dr Richard Peltier, Associate Professor at the University of Massachusetts Amherst, who led the letter.

This should be about science

The scientists’ outcry is notable because this stage is normally NOT politically controversial. Air pollution policy decisions have been politicized in the past, but we are still at the stage in the process where we should just be talking about the science.

For four decades, the EPA has relied on the advice of pollutant review panels in addition to its Clean Air Scientific Advisory Committee in order to ensure it has the best scientific evidence on the connection between ambient air pollutants and health effects. After the science is reviewed and revised, CASAC makes a recommendation to the EPA about what level of pollution would protect public health with an adequate margin of safety. The EPA Administrator then makes a decision on the standard.

This process has worked remarkably well over the years. It has enabled the best scientific advice to inform EPA decisions, it has provided ample opportunity for public participation, and importantly, it has allowed our country to keep the science separate from the policy—minimizing the potential for politicization in what should be scientific decisions.

Acting Administrator Wheeler is cutting science out of air pollution protection decisions

In light of this, it is no wonder that scientists are upset. Under Acting EPA Administrator Wheeler, this well-oiled process is being shaken up. The PM review panel was nixed in October, at the same time that independent members of CASAC, mostly from academic institutions, were removed and replaced almost entirely with members from state regulating industries (even though CASAC’s charter requires only one state representative).

On top of these changes, Wheeler’s EPA has made clear it is looking to expedite the whole review process—cutting out public drafts of the Integrated Science Assessment, limiting public and expert input, minimizing the analytical documents that have historically ensured careful science and policy impact assessments.  (For more about the new changes to the National Ambient Air Quality Standards and what they mean, check out my prior post here.)

The scientists will submit their letter as an oral comment this Wednesday at CASAC’s meeting to discuss the draft Integrated Science Assessment for Particulate Matter. It remains to be seen whether the new CASAC will take the advice of the letter signers and reinstate the Particulate Matter Review Panel, but it is clear the 206 air quality and public health experts are making their voices heard.

The text of the letter is below:

To: Acting Administrator Andrew Wheeler, Environmental Protection Agency, 1200 Pennsylvania Ave. NW, Mail Code 1101A, Washington, DC 20460

We write to express our deep concern with the recent dismissal of the Particulate Matter Review Panel, a long-standing and indispensable group of technical experts reporting to the Clean Air Scientific Advisory Committee (CASAC).

For the past 40 years, the United States has been well-served by independent, data-driven science, and this has enabled the Environmental Protection Agency (EPA) to meet part of its fundamental mission by protecting the public from air pollution. Non-political, fact-guided examination by scientific experts, such as those formerly comprising the Particulate Matter Review Panel, is essential for the EPA to receive the best scientific advice needed to protect public health. This process has always taken place in a transparent environment in order for all voices to be considered and decisions to be grounded in evidence.

The science of particulate matter’s impact on public health is a complex one that requires a qualified panel of experts. Particulate matter is an especially complicated pollutant because, unlike other EPA criteria pollutants, it is comprised of a mixture of many different chemical compounds that vary in concentration, composition, and physical size. Some of these compounds—even at low concentrations—are likely to pose disproportionate health risks to vulnerable populations throughout the country. In fact, exposure to particulate matter causes more than 88,000 early deaths (i) per year in the United States—more than firearms and motor vehicle traffic deaths combined (ii)—and this number appears to be growing over time. New science continues to be reported each week that requires interpretation by qualified experts who can apply understanding, scrutiny, and constructive criticism to each published report.

Without sufficient expertise by qualified, independent scientists, the EPA’s air pollution decisions are likely to lack the information necessary to provide an honest assessment of particulate matter impacts on health. The end result may be particulate matter standards that insufficiently protect the United States public, especially our most susceptible populations such as children and the elderly.

As professional scientists and engineers, we strongly object to sidelining science in this decisionmaking process. We strongly urge you to reinstate the Particulate Matter Review Panel to provide the Clean Air Scientific Advisory Committee, as well as your agency, with the best-possible scientific understanding.

(i) Cohen AJ, Brauer M, Burnett R, Anderson HR, Frostad J, Estep K, et al. 2017. Estimates and 25-year trends of the global burden of disease attributable to ambient air pollution: An analysis of data from the global burden of diseases study 2015. Lancet 389:1907-1918.
(ii) Murphy SL, Xu J, Kochanek KD, Curtin SC, Arias E. 2017. National Vital Statistics Reports: Deaths: Final Data for 2015. Centers for Disease Control and Prevention. Vol 66 No 6. Online at