Particulate matter and your health
Jump to: 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
February 2026 update: In July 2026, the Air Quality Control Commission will consider revising state regulations to reflect Colorado’s continued attainment with federal standards for PM10. PM10 refers to particulate matter that is 10 micrometers in diameter or smaller. Learn more and get involved in this rulemaking process:
- Review materials from the February 2026 PM10 rulemaking request. The commission will add more materials to the PM10 rulemaking hearing folder leading up to the July 2026 meeting.
- Become a party to the rulemaking hearing. More information is available on the commission’s web page on what party status means and how the process works.
- Submit written comments directly to the commission at cdphe.aqcc@state.co.us.
- To share verbal comments or listen to the rulemaking hearing, register for the July 2026 rulemaking hearing.
January 2025 update: The Colorado Air Quality Control Commission held a public hearing in January 2025 and adopted the Air Pollution Control Division’s recommendation concerning fine particulate matter. The division recommended that Colorado be designated as “in attainment” with EPA’s revised National Ambient Air Quality Standard for fine particulate matter. The air division submitted the recommendation to the EPA on Jan. 29, 2025, based on 2021-2023 monitored data. The division will post future updates on this web page as EPA completes the process for finalizing designations.
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 particles 2.5 micrometers or smaller. This is known as fine particulate matter, or PM2.5. Particulate matter 10 micrometers or smaller is known as PM10.
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 National Ambient Air Quality Standards for all of the criteria air pollutants. The particulate matter standards include measurements for both PM2.5 and PM10.
In February 2024, the EPA finalized an action to strengthen its annual health standard for fine particulate matter. Based on the air monitoring data and analysis by the division’s experts, Colorado is in compliance with the new annual federal standard for fine particulate matter.
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 web page.
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.