On this page: What is particulate matter? | Where does particulate matter come from? | How does particulate matter impact health? | Are there health standards for particulate matter? | How does the state monitor particulate matter levels? | How can I stay informed on particulate matter levels? | Contact Us
Update: The Colorado Air Quality Control Commission will hold a public hearing in January 2025 to consider adopting the Air Pollution Control Division’s recommendation concerning fine particulate matter. The division is recommending that Colorado be designated as “in attainment” with U.S. EPA’s new National Ambient Air Quality Standard for fine particulate matter. This is not a rulemaking hearing because it pertains to Colorado’s compliance status with an existing federal rule. There are opportunities to learn more and get involved in the public hearing:
- Review materials from the rulemaking request in the commission’s December meeting folder.
- Submit written comments directly to the commission at cdphe.aqcc@state.co.us.
- Register to offer a verbal public comment or listen to the January public hearing. A registration link will be available on the commission’s website about a week before the January 15-17, 2025 meeting.
What is particulate matter?
Particulate matter is an air pollutant made up of very small pieces of debris such as dust, dirt, or soot. Experts refer to particulate matter depending on the size of the small pieces of debris. For public health, the biggest concern is for particles that are 2.5 micrometers in size or smaller. This is known as fine particulate matter, or PM2.5.
Where does particulate matter come from?
Particulate matter in outdoor air comes mainly from combustion processes. This includes emissions from some industrial processes and vehicles that run on gas or diesel. The transportation sector is a very large source of particulate matter pollution in Colorado. Communities near busy roads tend to experience higher levels of particulate matter.
Natural events, especially wildfires, are also large sources of particulate matter in outdoor air. Colorado tends to experience higher levels of particulate matter during times when there’s a lot of wildfire smoke in the air.
Indoor air quality can also be impacted by particulate matter pollution from wood smoke. For example, buildings that use wood burning stoves may have higher levels of particulate matter inside.
How does particulate matter impact health?
Particulate matter is a respiratory irritant. It can also cause cardiovascular issues due to its extremely small size. When inhaled, fine particulate matter can get deep into the lungs or even enter the bloodstream. The smaller the size of particulate matter, the more it may impact health.
Health impacts from breathing fine particulate matter depend on several factors. This includes how much someone inhales and for how long. Some groups are more sensitive to air pollution than others. Sensitive groups include kids, older adults, and people with pre-existing health conditions such as:
- Asthma.
- Chronic obstructive pulmonary disease (COPD).
- Lung disease.
- Heart disease.
Symptoms from breathing particulate matter vary. More mild health impacts include:
- Respiratory inflammation.
- Breathing difficulty.
- Increased asthma attacks.
More severe health impacts include:
- Heart attack.
- Stroke.
- Early death.
Are there health standards for particulate matter?
The federal Clean Air Act identified particulate matter as one of six key air pollutants that can harm health and the environment. These are known as criteria air pollutants. The U.S. Environmental Protection Agency created health standards for all of the criteria air pollutants. These are known as National Ambient Air Quality Standards.
In February 2024, the U.S. EPA finalized an action to strengthen its annual health standard for fine particulate matter. The Colorado state health department fully supports the U.S. EPA updating its standards in accordance with the latest science and health studies.
How does the state monitor particulate matter levels?
The CDPHE Air Pollution Control Division operates 18 of its own permanent air monitoring stations statewide that can measure particulate matter. The division posts detailed information on several air pollutants, including particulate matter, its air quality monitoring, forecasts, and data webpage.
The division also references data from air monitoring stations operated by other regulatory agencies and reputable sources as much as possible.
How can I stay informed on particulate matter levels?
The CDPHE Air Pollution Control Division monitors and forecasts air quality year round. The division issues air quality alerts if forecasts show particulate matter levels may exceed federal health standards.
The division has several options for Coloradans to stay informed:
- Subscribe to receive emails on air quality forecasts and alerts depending on your location.
- Follow the Air Pollution Control Division on Facebook and Twitter.
- Call the advisory hotline at 303-758-4848.
Contact Us
Questions? Email the CDPHE Air Pollution Control Division at cdphe.commentsapcd@state.co.us.
Stay informed. Subscribe to receive email updates from the division.