For immediate release: May 20, 2024
BOSTON, MA – Replacing diesel school buses with electric school buses could generate up to $247,600 in climate and health benefits per bus, according to a new study by researchers at the Harvard T. H. Chan School of Public Health. The researchers found that these benefits — including lower greenhouse gas emissions and lower rates of adult mortality and childhood asthma — and the associated savings are strongest in large cities and among older bus fleets (2005 and earlier).
The study was published in The Proceedings of the National Academy of Sciences on May 20, 2024.
While the health and climate benefits of switching from diesel to electric vehicles are well-established, this is the first study to specifically outline how electric school buses can improve human and planetary health.
“Research on air pollution and climate change should seek to identify health benefits,” said lead researcher Cary Nadeau, the John Rock Professor of Climate and Population Studies and chair of the Department of Environmental Health. “Our findings can inform policymakers that greenhouse gas emissions and air pollution are reduced by implementing solutions such as the use of electric vehicles. Our data provide strong evidence that accelerating the continued transition to electric school buses will benefit individual, public and planetary health.”
There are about half a million school buses in use in the United States, a large portion of which are older, highly polluting diesel buses. Switching to electric buses is a difficult decision for local, state and federal officials because they are expensive and the health benefits are not well known.
To determine the impact of diesel and electric school buses on the climate, researchers compared the amounts of carbon dioxide emitted from the exhaust pipes of diesel school buses and from electricity generation and battery production in electric school buses. To evaluate the health impacts of buses, researchers compared how their emissions contribute to fine particulate matter (PM2.5) air pollution, which is linked to adult deaths and childhood asthma.
The study found that replacing an average diesel school bus in the U.S. fleet in 2017 with an electric bus resulted in total benefits of $84,200 per individual bus. Each electric school bus emits 181 metric tons less carbon dioxide than its diesel counterpart, which equates to $40,400 in climate benefits. Meanwhile, each electric school bus was associated with $43,800 in health savings, through reduced air pollution and lower rates of mortality and asthma in children.
The study also found that the health benefits of electric school buses vary depending on the location and age of the diesel bus being replaced. Large metropolitan areas—with populations of more than 1 million—derive the most significant health benefits from electrifying school bus fleets, given the larger number of people whose air quality is improved. The researchers calculated that in a large city, replacing a 2005 diesel school bus with an electric bus would achieve health benefits of $207,200 per bus.
“In dense urban areas where older diesel buses still make up most school bus fleets, the savings from electrifying these buses outweigh the replacement costs,” Nadeau said. “Not to mention how the tangible benefits of electric school buses can improve lives — especially for racial minorities and those living in low-income communities who are disproportionately affected by the daily health risks of air pollution.”
Nadeau and her colleagues note that the study did not address one important question: how electric school buses affect children’s exposure to cabin air pollution while riding the bus. Additional research on this topic could further inform policy decisions.
Ernani Choma, research associate in the Department of Environmental Health, and Lisa Robinson, senior research scientist and deputy director of the Center for Health Decision Sciences, were co-authors.
“Adoption of Electric School Buses in the United States: Health and Climate Benefits,” Ernani F. Chuma, Lisa A. Robinson, Carrie C. Nadeau, Proceedings of the National Academy of Sciences, 20 May 2024, doi: 10.1073/pnas.2320338121
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Photo: iStock/stu99
for more information:
Maya Brownstein
mbrownstein@hsph.harvard.edu
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Harvard T Chan School of Public Health It brings together subject matter experts from many disciplines to educate new generations of global health leaders and produce powerful ideas that improve the lives and health of people everywhere. As a community of leading scientists, educators, and students, we work together to move innovative ideas from the laboratory to people’s lives—not only making scientific breakthroughs, but also working to change individual behaviors, public policies, and health care practices. Each year, more than 400 Harvard Chan School faculty teach more than 1,000 full-time students from around the world and train thousands more through online executive education courses. Founded in 1913 as the Harvard-MIT School of Health Administrators, the college is recognized as America’s oldest professional training program in public health.
