EPA proposes a new rule to revise the primary standard for fine particle pollution
The EPA announced a proposed rule to strengthen the air quality standards for fine particle pollution also known as PM 2.5. Under the Clean Air Act, these are primary, health-based standards. This revised rule aims to better protect communities that are most overburdened by pollution. These fine particles are often emitted directly from a source such as construction sites or unpaved roads, smokestacks, and even fires. There are also other emission sources such as vehicles, industrial facilities and power plants that produce fine particles from the complex chemical reactions of sulfur dioxide and nitrogen oxides.
These fine particles often referred to as soot, can affect the respiratory system and cause serious health effects ranging from asthma and heart attacks to premature death. Since EPA completed its last review of the PM National Ambient Air Quality Standards in 2012, thousands of new scientific studies have demonstrated the dangers of soot exposure. Studies have found that these adverse health impacts disproportionately affect vulnerable populations including children, older adults as well as communities of color and low income across the country.
The proposed rule aims to address the impacts on public health by strengthening the primary annual particulate matter 2.5 standard. According to the proposal, the agency estimates that if finalized a strengthened primary annual PM 2.5 standard at a level of 9 µg/m3 from its current level at 12 µg/m3 would prevent up to 4,200 premature deaths per year and 270,000 lost workdays per year. Resulting in as much as $43 billion in net health benefits in 2032.
The EPA is also proposing a revision to other aspects of the PM standards such as monitoring requirements and the Air Quality Index (AQI), intended to help states and tribes to meet the revised standards while simultaneously reducing the risk to public health. The Agency is proposing to retain the primary 24-hour PM 2.5 standard of 35 µg/m3, while taking comment on revising this level to as low as 25 µg/m3. This proposal is the latest in a broader suite of programs aimed at reducing air pollution. Some of these related 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 aimed at controlling pollution from heavy-duty trucks. EPA will accept public comment for 60 days after the proposal is published in the Federal Register. The agency also plans to conduct a virtual public hearing over several days for this proposed rule-making. After reviewing comments, final standards will be issued later this year.
Key to remember: EPA has set two primary standards for PM 2.5, which work together to protect public health: the annual standard, which EPA is proposing to revise, and a 24-hour standard, which the Agency is proposing to retain. The agency plans to finalize standards later this year.