Here's what we know so far about the proposal:
1. Soot pollution standards have not been updated in 10 years
The proposed rule, if finalized, would be the first update to the National Ambient Air Quality Standards (NAAQS) for particulate matter (PM) pollution since 2012, according to the EPA.
2. The EPA is proposing to lower the annual PM2.5 standard
The EPA is proposing to lower the annual PM2.5 standard from 12 micrograms per cubic meter (µg/m3) to between 9 and 10 µg/m3. PM2.5 refers to fine particulate matter with a diameter of 2.5 micrometers (μm) or less, about one-thirtieth the width of a human hair.
3. The EPA is proposing to retain the current 24-hour PM2.5 standard
The EPA is proposing to retain the current 24-hour PM2.5 standard of 35 µg/m3.
4. The EPA's proposal comes after a recommendation by the Clean Air Scientific Advisory Committee (CASAC)
In 2020, the CASAC recommended that the EPA review the PM2.5 NAAQS and consider lowering the standard.
5. Soot pollution can have a number of health effects
Exposure to soot pollution can cause a range of health effects, including respiratory and cardiovascular problems. Fine particulate matter can also exacerbate asthma and other chronic diseases.
6. The EPA is seeking public comments on the proposed rule
The EPA is seeking public comments on the proposed rule until March 28, 2023. The proposed rule will be published in the Federal Register in the coming days, and the EPA will hold a public hearing on the proposal in March.
7. The EPA will make a final decision on the PM2.5 NAAQS by the end of 2023
The EPA will consider the public comments and CASAC's advice when making a final decision on the PM2.5 NAAQS by the end of 2023.
