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EPA Proposes New, Stricter Air Quality Standard for Fine Particulate Matter, Public Comments Sought

The U.S. Environmental Protection Agency (EPA) on Friday announced a proposal to strengthen a key national ambient air quality standard (NAAQS) for fine particle pollution (PM2.5) to better protect communities, including those most overburdened by pollution.


Fine particles are able to penetrate deep into the lungs and can result in serious health effects that include asthma attacks, heart attacks, and premature death – disproportionately affecting vulnerable populations including children, older adults, those with heart or lung conditions, as well as communities of color and low-income communities across the nation.


These particles may be emitted directly from a source, such as construction sites or smokestacks; other particles form in the atmosphere as a result of complex reactions of chemicals such as sulfur dioxide and nitrogen oxides, which are pollutants emitted from power plants, industrial facilities like U.S. Steel’s Mon Valley Works, and vehicles.


EPA's proposal will specifically take comment on strengthening the primary (health-based) annual PM2.5 standard from a level of 12 micrograms per cubic meter to a level between 9 and 10 micrograms per cubic meter, reflecting the latest health data and scientific evidence. The Agency is also taking comments on the full range (between 8 and 11 micrograms per cubic meter) included in the Clean Air Scientific Advisory Committee's (CASAC) latest report.


Since EPA completed its last review of the PM NAAQS in 2012, thousands of new scientific studies have demonstrated the dangers of soot exposure. Strengthening the primary annual PM2.5 standard is expected to address disparities and would result in significant public health benefits. EPA estimates that if finalized, a strengthened primary annual PM2.5 standard at a level of 9 micrograms per cubic meter, the lower end of the proposed range, would prevent:

  • up to 4,200 premature deaths per year;

  • 270,000 lost workdays per year;

  • result in as much as $43 billion in net health benefits in 2032.

According to the release:


EPA will work closely with state, local, and Tribal air agencies to implement the revised primary annual PM2.5 standard when finalized. Today's proposal is the latest in a broader suite of programs under President Biden's leadership to reduce air pollution that threatens communities.


These programs include the proposed Good Neighbor Plan to address smog that affects downwind states, rules to address air pollution from oil and gas operations, including methane pollution, and other critical rules to reduce emissions from power plants and the transportation sector, such as the recently finalized Clean Trucks Rule that will slash smog- and soot-forming pollution from heavy-duty trucks.


EPA is also proposing to revise other aspects related to the PM standards – such as monitoring requirements and the Air Quality Index (AQI) – that will help states and Tribal Nations meet the revised standards while making significant strides toward protecting the health of all people, including at-risk populations. The Agency is proposing to retain the primary 24-hour PM2.5 standard of 35 micrograms per cubic meter, while taking comment on revising this level to as low as 25 micrograms per cubic meter.


By way of background: In June 2021, EPA announced it would reconsider the Trump administration's December 2020 decision to retain the 2012 PM2.5 standards because available scientific evidence and technical information indicated that the standards may not be adequate to protect public health and welfare.


In developing today's proposal, EPA considered the best available science and technical information, including an Integrated Science Assessment and updated Policy Assessment that were made available for public comment and for expert review by the Agency's Clean Air Scientific Advisory Committee (CASAC) and CASAC PM expert panel. EPA carefully evaluated the recommendations of the CASAC in developing the proposed rule.

EPA will accept public comment for 60 days after the proposal is published in the Federal Register. EPA will also conduct a virtual public hearing over several days for this proposed rulemaking, with the hearing beginning at 11:00 am Eastern Time and concluding at 7:00 pm ET each day.


EPA will begin pre-registering speakers for the hearing upon publication of the announcement of the public hearings in the Federal Register. Additional information will also be made available on the National Ambient Air Quality Standards (NAAQS) for PM webpage.

After reviewing comments, the Agency plans to issue final standards later this year.



Editor’s Note: GASP staff is reviewing the proposal. Stay tuned, we’ll have more information on how to make your voice heard on this important issue. Until then, here are some media links with more details about the announcement:



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