Skip to Content
Streetsblog Massachusetts home
Streetsblog Massachusetts home
Log In
Environment

Study: Highway Pollution Contributes to Higher COVID-19 Death Rates

About 40 cars occupy five lanes of highway in crawling traffic that stretches off to the horizon..

Traffic congestion on I-93 in downtown Boston. I-93 is one of the state’s biggest sources of air pollution, and a major source of regional traffic congestion.

A new nationwide study from Harvard's T.H. Chan School of Public Health suggests that people living in neighborhoods with higher levels of fine particulate air pollution are more likely to die from COVID-19 infection than patients from areas with cleaner air.

That's especially concerning for many of communities of color in Massachusetts, where the legacies of racist planning policies expose Asian, Latinx and Black neighborhoods to higher levels of tailpipe pollution from highways and other major roads.

The Harvard study compares the nation's county-level COVID-19 deaths (as of April 4) with each county's corresponding long-term average concentrations of pollution particles smaller than 2.5 micrometers in diameter, also known as PM2.5 or "fine particulate" pollution.

The authors concluded that counties with just one more microgram per cubic meter in their average PM2.5 levels had, on average, a 15 percent higher mortality rate from COVID-19.

The results "underscore the importance of continuing to enforce existing air pollution regulations to protect human health both during and after the COVID-19 crisis," write the study's authors.

Dust from worn tires, brake linings, and tailpipe exhaust make major highways one of the primary sources of PM2.5 pollution in cities. Some of the Commonwealth's worst ambient pollution levels are located in Boston’s Chinatown, home to chronically-congested entrances to the O’Neill tunnel and the I-90/I-93 interchange.

A 2019 study from the Union of Concerned Scientists found that Asian residents of Massachusetts generally breathe in 36 percent more PM2.5 pollution from traffic than the typical white Massachusetts resident; African American residents breathe about 34 percent more pollution, and Latinx resident breathe 26 percent more.

Major highways increase the health risks of fine particulate pollution exposure in the Commonwealth's biggest cities. Courtesy of the Union of Concerned Scientists.
Major highways increase the health risks of fine particulate pollution exposure in the Commonwealth's biggest cities. Courtesy of the Union of Concerned Scientists.
Traffic from major highways increases the health risks of fine particulate pollution exposure in the Commonwealth's biggest cities. Courtesy of the Union of Concerned Scientists.

Stay in touch

Sign up for our free newsletter

More from Streetsblog Massachusetts

New Trails to Look Forward To In 2026

Massachusetts opened over 40 miles' worth of new off-street trails in 2025, and more than a dozen new projects are expected to break ground in 2026.

December 23, 2025

Should the Orange Line to Roslindale Be The T’s Next Rapid Transit Expansion?

New housing, crowded buses, and underutilized commuter rail tracks help make the case to expand the Orange Line beyond Forest Hills, advocates argue.

December 19, 2025

More Buses to the Berkshires Coming In 2026

Link413, a partnership between three regional transit authorities, will introduce three longer-distance bus routes to connect North Adams, Pittsfield, Greenfield, and Northampton.

December 17, 2025

The Wrong Kind of Legacy: Old Red Line Trains Find It’s Getting Harder to Get Through Harvard

Riders should expect more delays today while track inspections limit Red Line traffic to a single track near Harvard.

December 16, 2025
See all posts