By Gretchen Goldman, Union of Concerned Scientists
In the latest of several moves targeting EPA air pollution protections, the Trump administration appears to have cut scientists out of a process for reviewing particulate pollution standards. The move breaks with a longstanding process for how the agency gets independent scientific review into its decisionmaking on air pollution protections. Without such expertise involved, EPA won’t have the best available scientific input to keep people safe from air pollution, as the law requires.
What the heck is PM2.5?
Particulate pollution or particulate matter (PM) is a kind of air pollution comprised of tiny solid particles (as opposed to gaseous air pollutants like ozone and carbon monoxide). These particles—especially ones smaller than 2.5 micrometers—are especially harmful because they can reach deep into human lungs, causing pulmonary and respiratory issues. In fact, particulate pollution kills more people in the US than any other form of air pollution, with tens of thousands of premature deaths per year attributed.
The good news is that PM pollution has gone down over the past few decades. Most of the country now meets the current annual PM standard. Cities and industrial sources have invested significantly in technology and other strategies to keep their particulate emissions down.
NAAQS: A Science-based Process
Our nation has had success in reducing PM because of our strong science-based standards. Under the National Ambient Air Quality Standards (NAAQS), every five years the EPA must revisit the science of particulate matter pollution and health. After a thorough review of all science available and extensive input from PM experts, the EPA administrator will set a standard based on what level of pollution protects public health with an adequate margin of safety. This process has worked remarkably well, at least until now.
The EPA relies on the air pollution and health expertise of its Clean Air Scientific Advisory Committee, and pollutant review panels. CASAC (as I’ve written about before) provides the EPA with a recommendation for the standard based on its understanding of the science. Both the EPA and CASAC rely on help from pollutant review panels to ensure they are using and interpreting correctly the best available science.
These review panels are comprised of experts on the pollutant under review specifically, allowing the agency to benefit from subject matter expertise. For example, CASAC will include folks with air pollution modeling or monitoring expertise and epidemiologists, but the PM review panel might include experts on the toxicology of particulates or an expert on particulate measurement error. This is especially important because CASAC is small (seven people). No matter how expert, it would not be possible for this group to have working expertise of all elements of the relationship between a pollutant and health AND have that knowledge for all six criteria pollutants under CASAC’s purview. As a result, EPA decisions on pollution standards can benefit from scientific expertise on all facets of the science on particulates and health.
Think of it this way: You could create a team of seven doctors from different disciplines to oversee your general health but if you developed a brain tumor you’d probably want the advice of a specialist who had experience in brain surgery. Likewise, EPA needs the help of specialists to fully assess the state of the science on individual pollutants.
Nixing the PM (and Ozone) Review Panels?
Yesterday, the EPA issued a statement noting that CASAC would be leading the review of the science for PM and ozone standard updates, with no mention of the PM and ozone review panels that have always been convened to inform the scientific assessments. This is a break with how the agency has always done things. By nixing these panels, the EPA would be cutting off the vital expertise it needs to get the science right on the health effects of air pollutants.
The administration might claim to be making this move in the name of streamlining but there are much bigger consequences to eliminating science from the process. Sure, it will be a faster process to update the PM standard without a review panel, but we’ll also have a less science-based process. Review panels effectively serve as a public peer-review of the EPA’s integrated science assessments, which detail the state of the science on pollutants. Without a PM review panel, there is far less expert input informing the PM standard.
But perhaps this is precisely the point. The administration has made clear that they are interested in fast-tracking the PM and ozone reviews in order to set new standards before the end of the administration. This is an aggressive timeline, considering that the EPA is only required to update the standards every five years, and usually needs more time to conduct the careful, science-based process of characterizing the state of the science on a pollutant’s health effects and working with scientific experts to issue a standard that is protective of public health. If you can eliminate this careful scientific assessment, you can speed up the process, but at the expense of public health.
An EPA hostile to clean air
The announcement is especially concerning in light of the other changes that the Trump administration is making to air pollution policy and science advice at the EPA.
- Ongoingly the administration has been gutting science advisory committees at the EPA, replacing independent scientists with conflicted and unqualified individuals. Yesterday’s announcement continued this pattern, by removing four independent experts on CASAC and replacing mostly with individuals that work for state agencies. Only one academic scientist remains on CASAC, a committee historically dominated by academic scientists with extensive publication records on air pollution and health research. The administration is treating advisory committee positions like political appointments. In reality, the science advisory committee are intended to capture the breadth of scientific understanding—not to have specific policy views, and not to get stakeholder input.
- Last April a Presidential Memorandum outlined other changes to the National Ambient Air Quality Standards process, including restricting the kinds of science that EPA can use to inform the standards for PM and other pollutants. Implementation of these changes will limit the science EPA looks at in determining the relationship between air pollutants and health, i.e. the science that determines the health-based air pollution standards.
- PM has also been the primary target of the EPA’s proposed rule to restrict the science that EPA can use in decisionmaking broadly. Chronic exposure to particulates is linked to premature deaths. As a result, reducing PM pollution has a huge bang per buck, saving many lives with every improvement in air quality. This fact is inconvenient for industries that want to continue to emit particulate pollution, making PM science a long-time target by ideological and financial interests that don’t want the tighter PM standards that save lives. The proposed rule to restrict EPA’s use of science is the latest assault to undermine the use of the science on PM’s health impacts.
Less Science, More Soot
These changes to the air pollution standard setting process will make it easier for the administration to weaken air quality standards for particulate matter and ozone. With less science and fewer scientists to inform decisionmakers, challenge assumptions, and verify scientific assertions, we are on a path toward political decisions cloaked in science. The administration might be able speed up the process by removing the crucial steps where the science is assessed, and experts weigh in, but this will come at the expense of our health. Can the EPA protect public health if it doesn’t take the time to determine what level of pollution is unsafe?
If the PM standard is weakened, public health will undoubtedly suffer. Pollution sources would be able ease controls on their pollution and potentially build new polluting facilities in more places. And the health burdens won’t fall equally. Low-income communities and communities of color that are already disproportionately burdened by air pollution from industrial and traffic sources are likely to be harder hit. Vulnerable populations like the children, the elderly and those with lung diseases are more likely to face health effects of increased soot in the air. In near literal terms, by removing the science, we remove the air from our lungs.