Lung Association “State of the Air”2026 Report Delivers Mixed Results in Montana as Missoula and Helena Ranked Among Most Polluted in Nation for Particle Pollution Days

Today, the American Lung Association released its 27th annual “State of the Air” report, which finds that nearly half of the children in the U.S. are breathing unhealthy levels of air pollution, including 89,603 kids in Montana. While Missoula ranked amongst the cleanest cities for ozone pollution, the area ranked 26th worst in the nation for short-term particle pollution. Missoula also received an F grade for annual particle pollution.

The Lung Association’s “State of the Air” report grades counties’ air quality in terms of unhealthy levels of ground-level ozone air pollution (also known as smog), and year-round and short-term spikes in particle pollution (also known as soot) over a three-year period (2022-2024). The report also ranks counties and metropolitan areas in cleanest and most polluted lists for each pollutant. Both ozone and particle pollution can cause premature death and other serious health effects such as asthma attacks, heart attacks and strokes, preterm births and impaired cognitive functioning later in life. Particle pollution can also cause lung cancer.

Infants, children and teens as a group are more susceptible to the health impacts of air pollution. Their lungs are still developing; they breathe more air for their body size than adults and they are frequently exposed to outdoor air. Air pollution exposure in childhood can cause long-term harm, including reduced lung growth, new asthma cases and increased risk of respiratory diseases.

“Clean air is essential to the health and wellbeing of families across Montana. Children deserve to breathe air that won’t make them sick,” said Carrie Nyssen, senior director of advocacy for the American Lung Association. “Unfortunately, too many Montanans are living with unhealthy levels of particle pollution. This air pollution is causing kids to have asthma attacks, contributing to chronic health conditions, and making people who work outdoors sick.” 

Nyssen added: “To compound the issue further, the U.S. Environmental Protection Agency’s (EPA) rollbacks of critical healthy air rules are impacting our residents. We urge Montana policymakers to take action to improve our air quality, and we are calling on everyone to tell EPA that our kids’ health counts.”

Nationally, the report found that 33.5 million children in the U.S., or 46% of people under 18 years old, live in an area that received a failing grade for at least one measure of air pollution. In total, 44% of people of all ages in the U.S. (152 million people in total) live in a county that received a failing grade for at least one measure of air pollution. 32.9 million people live in counties with failing grades for all three measures.

Key Findings for Billings, MT

Ground-level Ozone Pollution: 
Ozone “smog” affects the largest number of people in the U.S. Smog forms when gases from tailpipes, smokestacks, factories and other pollution sources react with sunlight. It is a powerful respiratory irritant with effects that have been likened to a sunburn on the lungs.  

• Billings, MT had incomplete data for ozone pollution in this year's report.
  • The metro area had no data collected for ozone in last year's report.   

Particle Pollution: 
Fine particle pollution can be extremely dangerous and even deadly. These particles come from wildfires, wood-burning stoves, coal-fired power plants, diesel engines and other sources. The report has two grades for particle pollution: one for “short-term” particle pollution, or daily spikes, and one for the annual average “year-round” level that represents the concentration of particles in each location.

• Billings, MT ranked 82nd worst in the nation for short-term particle pollution.
  • The ranking was based on the area’s worst county’s average number of unhealthy days - 2.3 days per year, a D grade, in Yellowstone County, Montana.
  • This was better than the area's ranking in last year's report of 30th worst, with 5.8 days per year, an F grade.  
• For the year-round average level of particle pollution, the area’s worst county, Yellowstone County, Montana, received a passing grade for pollution levels below the federal standard. 
  • Billings, MT ranked 177th worst in the nation.
  • This was better than the area's ranking in last year's report of 134th worst in the nation. 

In addition to the Billings metro area, other notable findings include:

• Helena, MT ranked 169th worst in the nation for ozone pollution. The ranking was based on the area’s worst county’s average number of unhealthy days - 0.3 days per year, a B grade, in Lewis and Clark County. This was better than the area's ranking in last year's report of 165th worst, with 0.3 days per year, a B grade. 
  • Helena ranked 23rd worst in the nation for short-term particle pollution. The ranking was based on the area’s worst county’s average number of unhealthy days - 6.7 days per year, an F grade, in Lewis and Clark County. This was better than the area's ranking in last year's report of 20th worst, with 10.3 days per year, an F grade. 
  • For the year-round average level of particle pollution, the area’s worst county, Lewis and Clark, received a passing grade for pollution levels below the federal standard. Helena ranked 70th worst in the nation. This was worse than the area's ranking in last year's report of 89th worst in the nation.
• Bozeman, MT had no data collected for ozone pollution in this year's report. The metro area had no data collected for ozone in last year's report. 
  • Bozeman, MT ranked 180th worst in the nation for short-term particle pollution. The ranking was based on the area’s worst county’s average number of unhealthy days—0.3 days per year, a B grade, in Gallatin County. This was better than the area's ranking in last year's report of 98th worst, with 2 days per year, a C grade. 
  • For the year-round average level of particle pollution, the area’s worst county, Gallatin County, received a passing grade for pollution levels below the federal standard. Bozeman ranked 211th worst in the nation (best among the nation's cleanest cities). This was better than the area's ranking in last year's report of 205th worst in the nation (4th best among the nation's cleanest cities). 

The Lung Association is calling on everyone to urge EPA to value the health of America’s kids. Historically, EPA has played an essential role in protecting people’s health from air pollution. The current EPA has retreated from its public health foundation by rolling back clean air protections. This EPA has also taken the recent step of eliminating health-related information from its economic analyses, meaning that the costs of pollution to kids, families and communities will not be counted as policies are undone. EPA must not devalue kids’ health.

See the full report results and take action at Lung.org/sota.