Under the Clean Air Act, the U.S. Environmental Protection Agency has the responsibility of setting something called the National Ambient Air Quality Standards (often called NAAQS) The goal? To protect public health and the environment from harmful levels of outdoor air pollution. The NAAQS set limits on how much of six primary pollutants can be present in the air and require states to monitor and report on air quality in their regions. If a community has more pollution than the standards allow, they write and implement a cleanup plan to reduce emissions from sources like vehicles, power plants and industry.
The six pollutants that are currently regulated under the NAAQS are particulate matter, sulfur dioxide, nitrogen oxides, carbon monoxide, ozone and lead. These pollutants are known to have detrimental effects on human health, including contributing to respiratory and cardiovascular diseases, as well as environmental impacts such as causing haze or affecting climate change.
The heart of the NAAQS – or we would say the lungs – is the fact that they have to be science-based. The primary standards for each pollutant must reflect what the science shows is necessary to protect human health with an adequate margin of safety. Other considerations, like what technologies are available and what they cost, are taken into account when states write their cleanup plans. EPA is required to periodically review the science and update the standards if needed, as researchers are always learning more about the health effects of particle pollution.
The NAAQS have driven dramatic progress in reducing air pollution nationwide, but there’s still work to do – including updating many of the standards to reflect the latest science and best protect health. On January 6th, EPA proposed changes to the NAAQS for fine particulate matter air pollution, also known as PM2.5, particle pollution, PM or soot. While an update to the particle pollution standards is greatly needed, unfortunately, the proposal did not go far enough. The new proposed standard is inadequate to protect public health from this deadly pollutant.
The Problem with Particle Pollution
Particle pollution refers to a mix of tiny solid and liquid particles that are in the air we breathe. These particles that can be inhaled deep into the lungs and cause serious health problems, and the smaller they are, the more dangerous they can be. Particle pollution comes from many sources including factories, power plants, motor vehicles and equipment, wood burning fireplaces and wildfires. PM2.5 refers to particles smaller than 2.5 microns. For context, the average human hair is about 70 micrometers in diameter – making it 30 times larger than the largest fine particle.
Exposure to particle pollution can cause worsened asthma and chronic obstructive pulmonary disease (COPD); cause heart attacks, strokes, heart disease and congestive heart failure; cause lung cancer; increase risk of low birth weight or infant mortality and impaired lung function in children; and even shorten your life. According to the 2022 “State of the Air” report, 63.2 million people lived in counties with unhealthy spikes in particle pollution.
How did EPA Propose to Change the PM NAAQS?
The Lung Association has long been calling on EPA to tighten the particulate matter NAAQS to specific more protective levels. The current annual standard for PM2.5, governing the annual average levels of this pollutant, is 12 micrograms per cubic meter. Health organizations have called for that level to be tightened to 8 micrograms per cubic meter to best protect health, but EPA only proposed to tighten the standard to between 9 to 10 micrograms per cubic meter.
EPA has also proposed to keep the existing 24-hour standards at 35 micrograms per cubic meter. The 24-hour standard controls daily spikes in this pollutant, because short-term exposure is harmful too. Health organizations called for that standard to be tightened to 25 micrograms per cubic meter.
EPA’s proposal would help to reduce the number of premature deaths and illnesses caused by PM2.5 exposure, but not enough. The levels the American Lung Association is calling for would save thousands more lives and help ensure pollution cleanup in communities facing environmental injustices.
And it’s not just the Lung Association. The majority of EPA’s expert advisors, the Clean Air Scientific Advisory Committee, recommended the standards be strengthened further, calling for levels as low as 8 micrograms per cubic meter for the annual standard and 25 micrograms per cubic meter for the 24-hour standard.
How Can You Can Take Action?
Stronger standards for both the 24-hour and annual measures are critical to inform and protect the public from levels of particle pollution that could put their health at risk and further environmental injustice. This is vitally important in communities with a polluting source, like a power plant or port, located nearby.
“Health organizations and experts are united in their ask of EPA to finalize the national standards for particle pollution at 8 micrograms per cubic meter for the annual standard and 25 micrograms per cubic meter for the 24-hour standard,” said Harold Wimmer, President and CEO of the American Lung Association. “More protective standards are necessary to drive cleanup nationwide in communities that currently experience unhealthy levels of deadly particle pollution.”
EPA will take comments on their proposed changes to the particulate matter NAAQS for 60 days, and we need your help to make the case that they should strengthen the proposal and then quickly finalize it.
The American Lung Association encourages the public to urge EPA to strengthen and finalize these standards at Lung.org/stronger-standards. And if you’re a health professional, please use your expert voice to weigh in by signing this letter. Stronger standards mean better health.
Blog last updated: August 22, 2023