Vehicular emissions cause 342 premature deaths each year in Greater Boston

March 3, 2025

A new study found that the majority of these deaths are linked to nitrogen dioxide exposure through emissions from SUVs and other light-duty trucks on the road.

The health effects of traffic-related air pollution in the United States are well-documented, but the data on this public health burden is much more limited at the local level. A new study led by the School of Public Health and the Institute for the Environment at the University of North Carolina at Chapel Hill (UNC-IE) fills this gap by quantifying the health consequences of on-road air pollution in the Greater Boston area—as well as the vehicle types that emit the most pollution and place the greatest harm on residents’ health and safety.

Published in the journal Science of the Total Environment, the study found that emissions from on-road vehicles cause 342 premature deaths annually in Greater Boston. Nearly 90 percent of these deaths are linked to elevated levels of nitrogen dioxide (NO2) in the region.

The majority of these health damages were linked to emissions from light-duty trucks, such as SUVs, pickup trucks, vans, and minivans. SUVs have ranked in recent years the most popular car among residents in the Bay State.

The findings also showed that the greatest health damages to the region resulted from emissions from suburban driving, rather than city traffic.

The researchers applied fine-resolution air quality modeling to gain a deeper understanding of how air pollution from specific sources uniquely affects mortality rates in Greater Boston communities. The team hopes this advanced methodology can inform geographically targeted transportation policies and climate action plans in Boston and in cities across the nation.

“Our findings indicate that the health impacts of transportation in the Greater Boston area are substantial,” says study coauthor Jonathan Buonocore, assistant professor of environmental health.

“As we continue to decarbonize the on-road transportation sector, the health benefits of reducing co-pollutants need to be quantified,” says Sarav Arunachalam, corresponding and senior author of the study and deputy director of UNC-IE. “Policymakers in major urban areas like Boston can use this information to develop targeted local-scale policies for improving public health of their citizens.”

For the study, the researchers assessed national data on premature mortality rates and asthma exacerbations to evaluate the air quality and health effects of emissions from on-road vehicles, using the advanced air quality modeling to estimate spatial patterns of population exposure and gauge differences in health damages by vehicle type, emission source, and subregion.

Approximately 87 percent of the 342 premature deaths that occurred annually from on-road emissions were linked to NO2 concentrations. NO2 and fine particulate matter (PM2.5) were linked to 55,000 and 2,600 asthma exacerbations, respectively, each year. While SUVs and other light-duty trucks contributed to the highest burden of health consequences across the region, medium-duty trucks (such as firetrucks and school buses) and heavy-duty trucks (such as dump trucks and tractor-trailers) contributed to greater health damages per ton than SUVs and other lighter vehicles. And while total health damages were highest from suburban driving, the health damages driven by PM2.5 exposure were three times higher in urban communities than suburban communities.

The researchers say this data can inform Boston’s climate action plans, including Go Boston 2030 Revisioned, the city’s transportation plan that aims to improve safety, expand access to transportation, and reduce emissions. In a separate study published earlier this year in Environmental Research: Health, the researchers found that electrifying medium- and heavy-duty trucks in New York City yielded $2.4 billion in health benefits by preventing 248 deaths and 173 childhood asthma emergency department visits, among other benefits. Conversely, in their new study, the researchers found that exposure to pollution from on-road vehicles in Greater Boston led to more than $3.5 billion in annual health damages. As the city aims to achieve its goal to become carbon neutral by 2050, the team’s advanced modeling tool could enhance multiple projects and policies.

“Our high-resolution modeling could be used to evaluate health benefits of transportation, including expansion of public transportation, pedestrian and biking infrastructure, vehicle electrification, and policies such as congestion pricing to reduce vehicle trips into downtown Boston,” Buonocore says.

The study was led by UNC-IE’s Manish Soni, a postdoctoral research associate. At Boston University SPH, the study was also coauthored by alum Laura Buckley (SPH’24); Mary Willis, assistant professor of epidemiology; Patrick Kinney, Beverly Brown Professor of Urban Health; Jonathan Levy, chair and professor of environmental health; and Christopher Rick, (now former) postdoctoral associate in the Department of Environmental Health.

Story by Jillian McKoy, Boston University School of Public Health. Read the full story here.