2025 State of the Air Report: Air Quality Worsens in Boston Metro Area Due to Wildfire Smoke

The American Lung Association’s newly released 2025 State of the Air report reveals worsening air quality in the Boston-Worcester-Providence, MA-RI-NH metro area, with increased ozone smog and particle pollution contributing to greater health risks for residents. The report attributes much of this decline to widespread wildfire smoke in 2023, which impacted air quality across the region.

Notably, Washington County, RI, saw its ozone grade drop from a D to an F, placing the metro area among the three worst in the Northeast for ozone pollution. Additionally, Worcester County, MA, experienced an increase in daily particle pollution levels, with its B grade slipping to a C. Although year-round particle pollution levels showed slight improvement, the metro area remains the second worst in the Northeast for this pollutant.

The report also highlights a concerning national trend: 156 million people—46% of the U.S. population—are living in areas with unhealthy air pollution levels, underscoring the ongoing need for stronger clean air protections and climate action.

“The air pollutants covered in this report are widespread and can impact anyone’s health. 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,” said Daniel Fitzgerald for the American Lung Association. “Unfortunately, too many people in the Boston metro area are living with unhealthy levels of ozone and particle pollution. This air pollution is causing kids to have asthma attacks, making people who work outdoors sick and unable to work, and leading to low birth weight in babies. We urge Massachusetts policymakers to take action to improve our air quality, including legislation to reduce air pollution levels and increasing monitoring, and we are calling on everyone to support the incredibly important work of the U.S. Environmental Protection Agency (EPA).”

Ground-level Ozone Pollution in the Boston-Worcester-Providence, MA-RI-NH metro area: 
The “State of the Air” report looked at levels of ozone “smog,” the air pollutant affecting the largest number of people in the United States. The Boston-Worcester-Providence, MA-RI-NH metro area ranked 61st worst in the nation for ozone pollution. The ranking was based on the area’s worst county’s average number of unhealthy days—4.5 days per year, an F grade, in Washington County, Rhode Island. In last year’s report, the county recorded 3 unhealthy days per year, a D grade.  

Particle Pollution in the Boston-Worcester-Providence, MA-RI-NH metro area: 
The report also tracked short-term spikes in particle pollution, which can be extremely dangerous and even deadly. The Boston-Worcester-Providence, MA-RI-NH metro area ranked 114th 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—1.7 days per year, a C grade, in Worcester County, Massachusetts. Last year's report recorded 0.7 unhealthy days per year, capturing a B grade.  

For the year-round average level of particle pollution, the area’s worst county, Worcester County, Massachusetts, received a passing grade for pollution levels below the federal standard. The Boston-Worcester-Providence, MA-RI-NH metro area ranked 110th worst in the nation. This was better than the area's ranking in last year's report of 90th worst in the nation. 

In addition to the Boston-Worcester-Providence, MA-RI-NH metro area, other notable findings across Massachusetts include: 

• Not a single A grade was earned by any Massachusetts County for ozone or particle pollution. 
• The highest grade for ozone was a B, earned by Berkshire, Franklin, Hampshire, Middlesex and Worcester Counties. The other 8 reporting counties earned C or D grades. 
• Only Suffolk, Norfolk and Middlesex Counties earned B grades for short-term particle pollution. The other 8 reporting counties earned C or D grades.

The “State of the Air” report found that 156 million people in the U.S. (46%) live in an area that received a failing grade for at least one measure of air pollution and 42.5 million people live in areas with failing grades for all three measures. The report also found that a person of color in the U.S. is more than twice as likely as a white individual to live in a community with a failing grade on all three pollution measures. Notably, Hispanic individuals are nearly three times as likely as white individuals to live in a community with three failing grades.

Legislation is before the Massachusetts General Assembly that would create an advisory committee to identify pollution hotspots across the Commonwealth and increase air quality monitoring. The legislation would also set enforceable targets to reduce pollution levels by 50% by 2050 and 75% by 2035 and require high-efficiency air filtration in like schools and public housing located near major pollution sources. 

In this year’s “State of the Air” report, the Lung Association is calling on everyone to support the U.S. Environmental Protection Agency. EPA is essential to protecting people’s health from ozone and particle pollution. Without EPA staff and programs, families won’t know what’s in the air they are breathing, and efforts to clean up air pollution will be undone. Join the American Lung Association in advocating to protect EPA’s expert staff and lifesaving programs. See the full report results and take action at Lung.org/sota. 

Get involved and help the mission of American Lung Association. The LUNG FORCE Walk Providence is coming up on June 21^st, and the Autumn Escape Bike Trek is right around the corner on September 26-28. Register today and join us!