New Report: Boston-Worcester-Providence Metro Area Earns Failing Grades for Ozone and Daily Particle Pollutants; New Hampshire Counties Pass for All Measures with Grades

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. The reports finds that the Boston–Worcester–Providence, MA–RI–NH metro area (which includes five of the state’s ten counties, and 79% of the state’s population) continues to struggle with unhealthy air quality, earning failing grades for both ozone smog and short-term particle pollution, despite showing improvement in year-round particle pollution levels. 

In contrast, in New Hampshire itself, all seven counties with results for at least one measure of air pollution continued to post passing grades. For ozone smog, no county got worse than in last year’s report and some improved. All five counties with results for the daily measure of fine particle pollution showed a modest improvement. 

Parts of the state showed improvements or remained unchanged for certain pollution measures, but grades varied, highlighting air quality contrasts across New Hampshire communities. In particular:

• Coos and Rockingham Counties were tied for worst in the state for ozone smog, both improving slightly but continuing to earn C grades.
• Cheshire and Hillsborough Counties were tied for worst in the state for the daily measure of fine particles, earning B grades after last year’s Cs. 
• Though passing , Cheshire County was also worst in the state for the year-round average of particle pollution.
• Four Counties in New Hampshire earned A grades with zero days of unhealthy air pollution: Belknap and Merrimack for ozone, Rockingham for daily particles, and Grafton for both measures.
• Hillsborough County was the cleanest in the state for the year-round average of particle pollution and was tied for 13th cleanest county in the nation for this measure.

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 New Hampshire. Children deserve to breathe air that won’t make them sick,” said Lance Boucher, Division Assistant Vice President for the American Lung Association. “Unfortunately, too many people in the New Hampshire are living with unhealthy days of ozone and particle pollution. This air pollution is causing kids to have asthma attacks, contributing to chronic health conditions, and making people who work outdoors sick.” 

Boucher 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 New Hampshire 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 Boston-Worcester-Providence, MA-RI-NH metro area: 
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 of the lungs.   

• The Boston-Worcester-Providence, MA-RI-NH metro area ranked 57th worst in the nation for ozone pollution. 
  • The ranking was based on the area’s worst county’s average number of unhealthy days—4.8 days per year, an F grade, in Washington County, Rhode Island. 
  • This was worse than the area's ranking in last year's report of 61st worst, with 4.5 days per year, an F grade.   

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. 

• The Boston-Worcester-Providence, MA-RI-NH metro area ranked 53rd 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—3.3 days per year, an F grade, in Essex County, Massachusetts. 
  • This was worse than the area's ranking in last year's report of 114th worst, with 1.7 days per year, a C grade.   
• For the year-round average level of particle pollution, the area’s worst county, Plymouth and Worcester Counties, Massachusetts, received a passing grade for pollution levels below the federal standard.  
  • The Boston-Worcester-Providence, MA-RI-NH metro area ranked 164th worst in the nation. 
  • This was better than the area's ranking in last year's report of 110th worst in the nation.  

In addition to these findings, other notable results include:  

• The Keene-Brattleboro, NH-VT metro area showed improved rankings across all three pollution measures, improving from a C to a B grade for daily fine particle pollution and retaining a B for ozone smog, while year-round particle pollution also improved and continued to earn a passing grade. The area ranked 169th worst in the nation for ozone pollution with a B grade. This ranking is based on an average of 0.3 unhealthy days per year in Cheshire County, New Hampshire, unchanged from last year’s number of days although it then had a slightly worse ranking of 165th. The metro area also ranked 154th worst for short-term particle pollution, earning a B grade, improving from a C grade and a ranking of 139th last year; and ranked 181st worst for year-round particle pollution, which earned a passing grade in Cheshire County, improving from 176th worst last year.

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.