Replacing old diesel school buses with new electric school buses has the potential to generate as much as $247,600 in combined climate and health benefits per bus, based on a recent study. The research revealed that these benefits, such as decreased greenhouse gas emissions and lower rates of adult mortality and childhood asthma, and the resulting cost savings, are most significant in urban areas and among fleets with buses manufactured before 2005.The benefits of switching from diesel vehicles to electric ones have been well established for both human and planetary health. A new study from the Harvard T.H. Chan School of Public Health found that these benefits, which include reduced greenhouse gas emissions, lower rates of adult mortality, and decreased childhood asthma, are most pronounced in large cities and among older bus fleets (built in 2005 and before).
The research will be featured in The Proceedings of the National Academy of Sciences on May 20, 2024, and it is the first of its kind to specifically quantify the ways in which electric school buses can improve human and planetary health.”Research into the connection between air pollution and climate change needs to focus on measuring the positive impacts on health,” stated Kari Nadeau, the John Rock Professor of Climate and Population Studies and head of the Department of Environmental Health. “Our results can provide valuable information to policymakers on the reduction of greenhouse gas emissions and air pollution through the adoption of solutions such as electric vehicles. Our data provides compelling evidence that expediting the shift to electric school buses will improve individual, public, and global health.”
In the U.S., there are approximately 500,000 school buses in operation, with a significant number of them being older and emitting high levels of pollutants.
Transitioning from polluting diesel buses to electric buses presents a challenging decision for local, state, and federal officials due to the high cost and the lack of awareness about the health benefits.
To measure the environmental impact of diesel and electric school buses, the researchers conducted a comparison of the carbon dioxide emissions from the tailpipes of diesel school buses and the electricity generation and battery production of electric school buses. In addition, the researchers assessed the health impacts of the buses by comparing how their emissions contribute to fine particulate air pollution (PM2.5), which is associated with adult mortality and the development of childhood asthma.
In 2017, a study discovered that replacing a regular diesel school bus in the U.S. fleet with an electric one resulted in $84,200 in total benefits for each individual bus. The electric school bus emitted 181 fewer metric tons of carbon dioxide compared to the diesel bus, which equates to $40,400 worth of climate benefits. Additionally, each electric school bus contributed to $43,800 in health savings due to reduced air pollution, lower mortality rates, and decreased childhood asthma.
The study also revealed that the health benefits of electric school buses can vary based on the location and the age of the diesel bus being replaced.
Large metropolitan areas, which are cities with a population of more than one million, experience the greatest health advantages from converting school bus fleets to electric power. This is due to the larger number of individuals whose air quality is improved. The researchers determined that in a large city, replacing a 2005 diesel school bus with an electric bus would result in $207,200 in health benefits per bus.
“In densely populated urban areas where old diesel buses are still used in most school bus fleets, the cost savings from electrifying these buses exceed the costs of replacement,” Nadeau explained. “Not to mention the tangible benefits of Electric school buses have the potential to significantly improve the lives of people, especially those from racial minorities and low-income communities who are disproportionately affected by the health risks of air pollution on a daily basis. Nadeau and her colleagues pointed out that while their study addressed many important aspects, it did not investigate the impact of electric school buses on children’s exposure to in-cabin air pollution while they are on the bus. Further research in this area could provide valuable insights for making policy decisions. Ernani Choma, a research associate in the Department of Environmental Health, and Lisa Robinson, a senior research scientist and deputy director of the Center for Health Decisions, were also involved in the study.
