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Act Now or Forever Hold Your Breath: Tell the EPA to Adopt Stronger PM2.5 Standards

Updated: Mar 13, 2023



The U.S. Environmental Protection Agency (EPA) in January recommended strengthening the National Ambient Air Quality Standard (NAAQS) for fine particulate matter (PM2.5), having determined “the current primary PM2.5 standards are not adequate to protect public health with an adequate margin of safety.”


The EPA is considering a range of options but if the annual PM2.5 standard is lowered to 10.0 micrograms per cubic meter (ug/m3) – a level at the weaker end of the proposed changes – one EPA projection shows Allegheny County might be one of just 24 counties across the nation still failing to meet the revised standard a decade from now.


The EPA’s final decision on revising the PM2.5 NAAQS will impact air quality locally, and how strict the final standard will be is still an open question that you can help decide.


The EPA is accepting public comments on its proposed revision to the NAAQS as well as an “array of issues” associated with it such as environmental justice concerns and advancements in air pollution monitoring. That means you can make your voice heard on several aspects of the new standard.


Even better, you have choices for how to make your voice heard.


There are petitions and sign-on letters circulating that you can add your name to. There are thousands of pages of EPA and scientific analysis you can review before submitting your own detailed insights. Somewhere in the middle, GASP has identified a few topics we think EPA should hear about from concerned individuals.


It’s not a short read, but if you want to tell EPA what you think about the new PM2.5 standard, we’ve laid out a few options below.


But quickly, before moving on, two notes:

1. The EPA called this the “soot” standard in some of its outreach. We’re calling it the PM2.5 NAAQS because that’s what the regulations call it. Same difference really.

2. We use the abbreviation NAAQS a lot in the rest of the article. If you read it as “nacks” in your head, that might help you read through it more seamlessly.



PM NAAQS Background: 52 Years in a Just a Few Lines


The EPA first set a NAAQS for particulate matter in 1971. EPA acknowledged at the time that “scientific knowledge of the health and welfare hazards” associated with particulate matter was “imperfect,” but pledged to “increase and improve” that knowledge.


By 1997, public health research, as well as techniques for measuring air quality, had “increased and improved” to the point regulators could establish with certainty that particulate matter measuring 2.5 microns or less – hence the 2.5 in PM2.5 – had an especially adverse impact on human health. The EPA determined that both a daily standard and an annual average standard would guard against the impacts of short-term and long-term exposure.


In the past 25 years, the EPA strengthened the standards as studies continued to show increased levels of PM2.5 associated with premature mortality as well as harm to not only the respiratory system (lungs, nasal passage, etc.) – as air pollutants tend to cause – but also the heart, brain, and other systems.


Earlier this year - and based on the best and most reliable scientific knowledge currently available - the EPA proposed lowering the annual PM2.5 NAAQS from 12.0 ug/m3 to within the range of 9.0 to 10.0 ug/m3 and keeping the current 24-hour PM2.5 NAAQS of 35 ug/m3.


Importantly, the EPA didn’t stop there.


The “array of issues” we mentioned above that the EPA is considering include an annual PM2.5 NAAQS as low as 8.0 ug/m3 or as high as 11.0 ug/m3, a 24-hour NAAQS of 25 or 30 ug/m3, requiring increased air quality monitoring for populations at increased risk of adverse health effects, and the relevance and limitations of international studies (to name a few).



Citizen Power, Engage!


With so many topics to choose from, of course, now you can’t wait to get cracking on that gem of a comment, right? Not so sure? We understand. It’s a lot to unpack, learn, read, and decipher.


We want to help.


To support many approaches for many concerned readers, we came up with a sort of “choose your own adventure” approach to civic engagement.


On one path, you can back GASP colleagues, allies, and partners who have already created petitions, letters, and the like, ready-made for you to support. One great example: Our friends in the Climate Action Coalition put together a quick and easy way to advocate for stronger standards.


For those who’d like to submit a quick comment, here’s the form.



The second path isn’t as straightforward but it provides the opportunity to tell the EPA your story and/or offer input on an aspect of the proposed NAAQS you feel strongly about.


Obviously, we can’t address every detail of the EPA’s proposed NAAQS revision here. If you’re interested in learning more, EPA’s official announcement of the proposed PM2.5 NAAQS changes fully explains the actions EPA is taking and the input it is seeking.


In addition, EPA’s PM2.5 NAAQS webpage as well as a separate EPA webpage addressing the NAAQS revision contain additional resources.


If you’re not interested in completely going it alone, GASP identified a few topics that we believe are important locally. Please consider adding these issues or some version and/or combination of them to any comment you submit.


1. As part of the EPA’s reason for not lowering the 24-hour PM2.5 standard, the agency determined that areas meeting the annual NAAQS usually don’t exceed the 24-hour NAAQS. Even rarer in such areas –according to the EPA – are instances of very high short-term peaks lasting just a few hours (called “sub-daily” concentrations). Specifically, for areas with good air quality, two-hour PM2.5 concentrations rarely exceed 30 ug/m3 and in problematic areas, they rarely exceed 80 ug/m3. You can read more about EPA’s reasoning here. Unfortunately, we suffer through these “rare” circumstances too often: In 2022, there were seven days in Allegheny County with a two-hour PM2.5 concentration over 100 ug/m3. While there were no such days in 2020, there were five of those days in both 2021 and 2019. Rare or not, it is critical we tell EPA the new PM2.5 NAAQS cannot ignore the problems we face locally.


2. Calling all citizen scientists: The EPA is seeking input on approaches and/or products related to the use of data from non-regulatory, low-cost air sensors (e.g., Purple Air). The EPA listed possible uses such as science education, supplementing regulatory air quality measurements, and conducting research, but did not propose any specific plan of action. You can read more about the input EPA is asking for here (the link is to the first of six relevant paragraphs).


3. The burden of PM2.5 pollution is not felt equally around the country. The EPA is well aware that “sub-populations at potentially greater risk from PM2.5 exposures include children, lower socioeconomic status populations, minority populations (particularly Black populations), and people with certain pre-existing diseases (particularly cardiovascular disease and asthma).” One way the EPA wants to address this issue is to modify its PM2.5 monitoring network requirements to include an environmental justice factor. You can read more about EPA’s proposed changes here (the link is to the first of several paragraphs that address this topic in detail).


4. Although the EPA is not requesting comments specifically on how environmental justice considerations will affect the implementation of the revised NAAQS, “information on this topic may be submitted for informational purposes.” You can read more about what the EPA is interested in hearing about here.


If you aren’t sure what to write, remember that the only way the EPA will know how you’ll be impacted by the agency’s action is if you tell them. Begin with your own personal experiences and go from there.


Finally, if you took this path, remember that the last step is to submit your comment. To do that, all you need to do is go to EPA’s official announcement of the proposed PM2.5 NAAQS changes. In the upper right-hand corner of this webpage, click on a green box labeled Submit a Formal Comment. A fill-in-the-blanks form will open, follow the instructions, and you’re done.


If you prefer to submit a comment via email, snail mail, or hand delivery, instructions for these options are part of the official announcement link above.


Comments must be received on or before March 28.


No matter what path you choose, we hope you’ll join GASP and many others who are demanding cleaner air.


Did you find this blog helpful? We hope so. Truth be told: We think about you all the time. Seriously. Our staffers get up early when we know air quality is expected to be abysmal so we can review the data, crunch the numbers, and let you know what to expect when you start your day. We attend subcommittee meetings, hearings, and webinars because we pride ourselves on being your eyes and ears on all things air quality. Help us continue to show up for all our fellow breathers by making a $5 donation today.



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