New Study Identifies Leading Source of Health Damages from Vehicle Pollution in 12 States and Washington, D.C.

(University of North Carolina at Chapel Hill Institute for the Environment) Tailpipe emissions caused an estimated 7,100 premature deaths in the Northeast and Mid-Atlantic in 2016 -- A new study finds that ozone and fine particulate matter from vehicle emissions in 2016 led to an estimated 7,100 deaths in the Northeast and Mid-Atlantic regions of the U.S. The study, published today in Environmental Research Letters, finds that pollution from tailpipe emissions is also traveling across state lines and harming the health of people living in cities and states downwind. Researchers at the University of North Carolina at Chapel Hill’s Institute for the Environment and the Center for Climate, Health, and the Global Environment at Harvard T.H Chan School of Public Health (Harvard Chan C-CHANGE) quantified the total and interstate deaths from transportation-related air pollution generated by five vehicle types in 12 U.S. states and Washington, D.C.

“The research confirms that recent efforts to electrify the bus fleet in New York City will have large health benefits—or, the biggest bang for the buck. The cross-border impacts underscore the need for regionwide action to curb transportation emissions,” said Saravanan Arunachalam, research professor and deputy director of the UNC Institute for the Environment. “What makes this study different from previous studies is that it connects the dots between where the pollution happens, and where the premature deaths occur.”

Using sophisticated source-receptor modeling, the study authors found that most states in the region were heavily impacted by out-of-state emissions. For example (see table below for more details):

“It is my hope that the results from this study will help demonstrate how serious air pollution from vehicles is to people living not only near high-traffic areas but also those living downwind of them,” said Calvin Arter, a graduate research assistant at UNC-Chapel Hill and lead author of the study. “And in doing so, provide the impetus for a collaborative approach to reducing the health impacts associated with on-road transportation-related air pollution.”

The study also identified the sources that have the largest impact per ton of pollution emitted in each state and metro area.

“The particular source region and type of vehicle responsible for the most health problems vary across the region. While particulate matter from New York City buses has the largest impact per ton of emissions in New York, in Massachusetts it’s heavy-duty trucks in Boston, and in Virginia it is light-duty autos,” said Jonathan Buonocore Sc.D., Research Scientist at Harvard Chan C-CHANGE. “As policymakers consider how to transform the transportation sector—the largest source of carbon pollution—this research offers a roadmap for where to target investments to most cost-effectively improve air quality and health.”

Researchers focused on ozone and fine particulate matter formed from on-road vehicle emissions using 2016 data from the most recent national emissions inventory. The health impacts from nitrogen dioxide pollution are also substantial but were not included in this study.

Importantly, the researchers also found that ammonia emissions play a stronger relative role in causing health damages compared to oxides of nitrogen. Regionally, ammonia emissions from vehicles were responsible for 740 premature deaths in 2016, more than 10% of the total deaths. Ammonia emissions from vehicles are an unintended by-product of catalytic converters and are unregulated in the U.S., and their role in urban air pollution has been generally underappreciated.

The study is part of the Transportation, Equity, Climate and Health (TRECH) Project, a multi-university research initiative independently analyzing the Transportation and Climate Initiative (TCI), and other policy scenarios. TRECH is based at Harvard Chan C-CHANGE. The TRECH team previously analyzed the health benefits of increased investment in biking and walking infrastructure. They are currently analyzing the impacts of increases in electricity demand from vehicle electrification and conducting a local case study in the greater metro area of Boston, Mass.

The TRECH Project is made possible thanks in part by a grant from the Barr Foundation to Harvard Chan C-CHANGE. READ MORE