Massachusetts Air Quality Worsened for Ozone, Finds 2020 ‘State of the Air’ Report

American Lung Association’s annual air quality report finds nearly half of Americans breathing unhealthy air; Boston metro area air quality ranked 38th most polluted for ozone

Editor’s Note: The full report, as well as trend charts and rankings for metropolitan areas and county grades are available at

The American Lung Association’s 2020 “State of the Air” report found the Boston metro area ranked as the 38th most polluted city in the nation for ozone, with more unhealthy days than reported in last year’s report. 8 out of the 14 reporting counties throughout the state followed suit, showing more unhealthy days of ozone, while the state did show some improvements for long- and short-term particle pollution.

The Lung Association’s annual air quality “report card” tracks Americans’ exposure to unhealthful levels of particle pollution and ozone during a three-year period. As the country continues to grapple with the COVID-19 pandemic, improving air quality is more important than ever – as studies have shown air pollution harms lung health, and emerging research links long-term exposure to particle pollution to increases in the death rate among COVID-19 patients. Once again, the report found that nearly half of all Americans were exposed to unhealthy air in 2016-2018. In the Boston metro area, ozone pollution placed the health of its residents at risk, including those who are more vulnerable to the effects of air pollution such as older adults, children and those with a lung disease.

"For many Americans, the COVID-19 pandemic has illustrated just how important lung health really is," said Dr. Andrea McKee, Director of the CT Lung Screening Program at Lahey Hospital and Medical Center (LHMC) and volunteer medical spokesperson for American Lung Association. "There is no short cut, no alternative to breathing.  We must do more to protect our lungs from anything that puts our ability to breathe at risk, be it a virus, tobacco smoke, or air pollution."

“This year marks the 50th anniversary of the Clean Air Act, which has been responsible for dramatic improvements in air quality. However, Massachusetts residents are largely breathing more unhealthy air compared to last year’s report, driven by extreme heat as a result of climate change, placing our health and lives at risk,” said American Lung Association’s National Assistant Vice President for State Public Policy Michael Seilback. “Furthermore, with nearly half of Americans breathing unhealthy air, our ‘State of the Air’ report shows that nationally, because of climate change, the nation is heading in the wrong direction when it comes to protecting public health.”

Each year the “State of the Air” provides a report card on the two most widespread outdoor air pollutants, ozone pollution, also known as smog, and particle pollution, also called soot. The report analyzes particle pollution in two ways: through average annual particle pollution levels and short-term spikes in particle pollution. Both ozone and particle pollution are dangerous to public health and can increase the risk of premature death and other serious health effects such as asthma attacks, cardiovascular damage, and developmental and reproductive harm. Particle pollution can also cause lung cancer, and new research links air pollution to the development of serious diseases, such as asthma and dementia.

This year’s report covers 2016, 2017 and 2018, the years with the most recent quality-assured data available collected by states, cities, counties, tribes and federal agencies. Notably, those three years were among the five hottest recorded in global history. Rising temperatures lead to increased levels of ozone pollution. Changing climate patterns also fuel wildfires and their dangerous smoke, which increase particle pollution. Ozone and particle pollution threaten everyone, especially children, older adults and people living with a lung disease. Although this report does not cover data from 2020, amid the COVID-19 pandemic, the impact of air pollution on lung health is of heightened concern. Learn more about that at

Ozone Pollution
Compared to the 2019 report, the Boston-Worcester-Providence metro area experienced more unhealthy days of high ozone in this year’s report leaving it with a ranking of 38th most polluted for ozone, compared to 43rd last year. (Our report uses the Boston-Worcester-Providence, MA-RI-NH-CT Consolidated Statistical Area as defined by the U. S. Office of Management and Budget, which includes Barnstable, Bristol, Essex, Middlesex, Norfolk, Plymouth, Suffolk, and Worcester, Massachusetts; Windham, Connecticut; Belknap, Hillsborough, Merrimack, Rockingham and Strafford, New Hampshire, and Bristol, Kent, Newport, Providence and Washington, Rhode Island.)

Four Massachusetts counties, Dukes, Worcester, Plymouth, and Essex, all saw decreased grades for ozone, while grades were maintained in Barnstable (F), Hampden (F), Windham (F), Bristol (F), Norfolk (D), Suffolk (C), Franklin (C) and Middlesex (B). Only Hampshire saw an improved grade, from a F to a D. Both Nantucket and Berkshire had incomplete grades.

“Ozone pollution can harm even healthy people, but is particularly dangerous for children, older adults and people with lung diseases like COPD or asthma.  Today, more than one in three Massachusetts residents live in a county with failing air pollution.” Said Dr. McKee. “Breathing ozone-polluted air can trigger asthma attacks in both adults and children with asthma, which can land them in the doctor’s office or the emergency room. Ozone can even shorten people’s lives.”

This report documents that warmer temperatures brought by climate change are making ozone more likely to form and harder to clean up. Significantly more people suffered unhealthy ozone pollution in the 2020 report than in the last three “State of the Air” reports.

Particle Pollution
“State of the Air” 2020 found that year-round particle pollution levels in Boston were slightly lower than in last year’s report, leading to a ranking of 64th most polluted for year-round particles.  All reporting counties continued to meet the national standard, although Plymouth and Suffolk did see slight increases in year-round particle levels from last year.

“Particle pollution can lodge deep in the lungs and can even enter the bloodstream. It can trigger asthma attacks, heart attacks and strokes and cause lung cancer,” said Dr. McKee.

“Year-round particle pollution levels had dropped in recent years thanks to the cleanup of coal-fired power plants and the retirement of old, dirty diesel engines. However, the increase we’ve seen nationally in particle pollution in this year’s report is a troubling reminder that we must increase our efforts to reduce this dangerous pollution,” said Seilback.

State of the Air” 2020 also tracked short-term spikes in particle pollution, which can be extremely dangerous and even lethal. The report found that Boston had fewer days when short-term particle pollution reached unhealthy levels – leading to its first time ranking as one of the cleanest cities for short-term particle pollution. Most reporting counties maintained their A grades, with the exception of Berkshire which declined from a A to a B.

“We all have the right to breathe clean, healthy air. The 50th anniversary of the Clean Air Act serves as a critical reminder that Americans breathe healthier air today because of this landmark law,” said Seilback. “At the same time, this year’s report shows that we must stand up for clean air – especially to safeguard our most vulnerable community members. Our leaders, both here in the Commonwealth of Massachusetts and at the federal level, must take immediate, significant action to ward off climate change and other threats to the quality of the air we all breathe.”

While the report examined data from 2016-2018, this 21st annual report also provides air pollution trends back to the first report. Learn more about Boston rankings, as well as air quality across Massachusetts and the nation, in the 2020 “State of the Air” report at For media interested in speaking with an expert about lung health, healthy air, and threats to air quality, contact Jennifer Solomon at [email protected] or 516-680-8927.

For more information, contact:

Jennifer Solomon
(516) 680-8927
[email protected]

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