Research

Alternate jet fuels reduce deaths

A new study by researchers at the UNC Institute for the Environment and the Harvard T.H. Chan School of Public Health finds that sustainable alternative jet fuels decrease premature death rates.

A jet taking off.
Photo credit: dsleeter_2000

Airplane emissions are estimated to be responsible for 16,000 premature deaths around the world each year. Driven by a 3.5% growth in passenger flights, aviation traffic is expected to rise over the next 20 years with a large increase in jet fuel consumption, creating air pollution that is known to cause adverse health effects.

A new study by researchers at Carolina’s Institute for the Environment and the Center for Climate, Health and the Global Environment at Harvard T.H. Chan School of Public Health finds that sustainable alternative jet fuels can decrease premature death rates in communities near airports and downwind but also suggests more work needs to be done.

Published in Environment International, the study uses data inventories from 2011 and 2016 to quantify health impacts from landing and take-off operations of commercial aircraft near airports in the continental United States.

The study quantified health effects by state and found California to be the most affected by the airport emissions. Other states with high impacts include New York, Pennsylvania, Illinois, New Jersey and Ohio.

The researchers looked at fine particulate matter (PM2.5), ozone (O3) and nitrogen dioxide (NO2) concentrations attributable to landing and take-off operations, which are known for causing adverse health effects and quantified health outcomes for mortality and multiple morbidity health results.

“We have previously quantified PM2.5 related health risk from aviation in various studies. The relatively large role of NO2-related health risk from aviation emissions is new, and the fact that the NO2-related health risk is not mitigated by the switch to sustainable alternate jet fuels emphasizes that more work needs to be done,” said Saravanan Arunachalam, research professor and deputy director of the UNC Institute for the Environment.

The study, funded by the Federal Aviation Administration through ASCENT — the Aviation Sustainability Center, also quantified impacts from two scenarios where 5% or 50% blends of sustainable alternative jet fuel are implemented.

“The Biden administration has new initiatives to increase the production of sustainable fuels for aviation in the next three decades,” Arunachalam added. “While this will reduce aviation emissions from fuel burn, our work shows that more work needs to be done specifically on the combustion end of the aircraft engine to make aviation even more sustainable.”

“As policies are enacted to encourage the shift to using sustainable alternative jet fuels, the results from this study can help inform how that shift will impact the health of communities near airports,” said Calvin Arter, postdoctoral research associate at the UNC Institute for the Environment. “And in the case of NO2-related impacts, this study may push those policies further to consider additional emission control strategies that help where sustainable alternative jet fuels fall short.”

The study found that:

  • An estimated 80 and 88 PM2.5-attributable and 610 and 1,100 NO2-attributable premature mortalities in 2011 and 2016, respectively.
  • An estimated net decrease of 28 and 54 in O3-attributable premature mortalities across the United States in 2011 and 2016, respectively, due to the large O3 titration effects near the airports.
  • Asthma exacerbations due to NO2 exposures from airport emissions increase from 100,000 in 2011 to 170,000 in 2016.
  • Implementing a 5% or 50% blend of sustainable alternative jet fuel in 2016 results in a 1% or 18% reduction, respectively, in PM2.5-attributable premature mortalities.
  • 50%-blended sustainable alternative jet fuel results in a 19% decrease in PM2.5 damages per ton of fuel burned and a 2% decrease in total damages per ton of fuel burned as compared to damages from traditional jet fuel.
  • LTO-attributable PM2.5 and NO2 premature mortalities increase by 10% and 80%, respectively, from 2011 to 2016 and that NO2-attributable premature mortalities are responsible for 91% of total LTO-attributable premature mortalities in both 2011 and 2016. Since LTO-attributable NO2 is unaffected by the implementation of sustainable alternative jet fuels, additional approaches focused on NOX reductions in the combustor are needed to mitigate the air quality-related health impacts from LTO emissions.

“This analysis provides further evidence for the enormous, but often overlooked, burden that direct exposure to NO2 has on mortality and asthma. Our new platform is able to begin shining a light on the serious health burden of NO2 exposure, and the benefits of strategies that reduce NO2 emissions,” said Jonathan Buonocore, research scientist at Harvard Chan C-CHANGE.

Carolina is one of 16 member institutions of ASCENT — the Aviation Sustainability Center, co-led by Washington State University and the Massachusetts Institute of Technology. ASCENT is a center of excellence for alternative jet fuels and environment and is funded by the FAA, NASA, the Department of Defense, Transport Canada and the Environmental Protection Agency. This consortium works to develop science-based solutions for all environmental impacts faced by the aviation industry and spans diverse disciplines from operations to emissions to environmental impacts and sustainability.