Mobile ObserVations of Ultrafine Particles: The MOV-UP study

plane taking off at Sea-Tac

DEOHS-led study finds communities around Sea-Tac Airport are exposed to a unique mix of air pollution associated with aircraft


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The Mobile ObserVations of Ultrafine Particles (MOV-UP) study analyzed the potential air quality impacts of ultrafine pollution particles from aircraft traffic on communities near and underneath Seattle-Tacoma International Airport (Sea-Tac) flight paths.

This two-year study, which ended in December 2019, was funded by the Washington State Legislature to assess ultrafine pollution particles within 10 miles of the airport in the direction of aircraft flight. The study was led by the UW Department of Environmental & Occupational Health Sciences and the Department of Civil and Environmental Engineering.

UW researchers collected air samples at numerous locations around Sea-Tac Airport over the course of one year between 2018 and 2019.

They found that communities underneath and downwind of jets landing at Sea-Tac Airport are exposed to a type of ultrafine particle pollution that is distinctly associated with aircraft. The study is the first to identify the unique "signature" of aircraft emissions in Washington.

The research team developed a new method to distinguish between pollution from jet traffic and pollution from other sources such as roadway traffic. Ultrafine pollution particles are emitted from both sources, but the research team found key differences in the particle size and mixture of particles they emitted.

The team then mapped each type of emission mixture to show its specific geographic footprint around the airport.

Although this study did not consider the health effects of exposure to roadway or aircraft-related pollution, other studies have linked exposure to ultrafine particles to breast cancer, heart disease, prostate cancer and a variety of lung conditions.

Read the full report about the study’s methodology and findings: Download now

What’s next

A new project, Characterization of Urban Ultrafine Particles, is starting up in Summer 2020. Funded by the University of Washington EDGE Center, this project aims to develop methods to increase our understanding of the chemical differences between ultrafine particles from different urban sources. 

Knowledge Gaps and Future Research

We identified three knowledge gaps in the process of analyzing results from this study. These were prioritized as follows by the Study Advisory Board:

Gap 1: What are the health effects of aircraft ultrafine particles?

The potential health effects from aircraft-related particle exposure still need major research. Questions include:

  • What are the chemical differences between ultrafine particles from roadway traffic and aircraft sources?
  • Are short-term health responses to roadway traffic and aircraft particles different? We could conduct a study of short-term health impacts on sensitive populations, such as pregnant women,
  • children, older adults or individuals with pre-existing diseases such as asthma, diabetes and cardiovascular disease.
  • Are there long-term health impacts of exposure to traffic and aircraft ultrafine particles?

Gap 2: What can we do to reduce human exposures to ultrafine particles?

Our study suggests that some neighborhoods may have more exposure to ultrafine particles than others due to proximity to roadway traffic and/or overlap with the plumes from aircraft emissions. Questions include:

  • How much ultrafine particle pollution infiltrates indoor spaces, particularly schools, daycares, elder care facilities and medical centers where it could potentially expose vulnerable populations?
  • What interventions are effective in reducing exposures in these settings? We could design a study that considers the effectiveness of HEPA filtration, whether noise mitigations might alter infiltration or whether LEED buildings or HVAC choices could alter infiltration.

Gap 3: How are exposures to ultrafine particles changing over time?

Roadway and aircraft traffic have changed in volume, travel patterns and per-unit emissions over time and will likely continue to change. Questions include: Are there important daily, seasonal and time trends in exposures? We could design a study to systematically monitor and model the impacts of changing roadway and aircraft traffic on ultrafine particle exposures.

The Washington State Legislature’s study proviso
"...$140,000 of the general fund (state appropriation for fiscal year 2018) and $140,000 of the general fund (state appropriation for fiscal year 2019) are provided solely for the University of Washington School of Public Health to study the air quality implications of air traffic at the international airport in the state that has the highest total annual number of arrivals and departures.

The study must include an assessment of the concentrations of ultrafine particulate matter in areas surrounding and directly impacted by air traffic generated by the airport, including areas within 10 miles of the airport in the direction of aircraft flight paths and within 10 miles of the airport where public agencies operate an existing air monitoring station.
The study must attempt to distinguish between aircraft and other sources of ultrafine particulate matter and must compare concentrations of ultrafine particulate matter in areas impacted by high volumes of air traffic with concentrations of ultrafine particulate matter in areas that are not impacted by high volumes of air traffic.

The University must coordinate with local governments in areas addressed by the study to share results and inclusively solicit feedback from community members. By December 1, 2019, the University must report study findings, including any gaps and uncertainties in health information associated with ultrafine particulate matter, and recommend to the Legislature whether sufficient information is available to proceed with a second phase of the study."


About the partners

Representatives from government agencies, cities and community organizations served on an external Study Advisory Board to provide feedback on the study design, methods and findings. The board included representatives from the following organizations:

Puget Sound Clean Air Agency
US EPA Region X
Washington State Department of Ecology
Public Health—Seattle & King County
Port of Seattle
FAA Northwest Mountain Region
Washington State Department of Health
Quiet and Healthy Skies Task Force
Beacon Hill CHAC
Washington State Department of Commerce
Cities of Burien, Des Moines, Normandy Park, SeaTac and Tukwila
Offices of Representatives Tina Orwall and Mike Pellicciotti, Washington State House of Representatives
Office of US Congressman Adam Smith
Office of US Congresswoman Pramila Jayapal

Contact us

Edmund Seto, PhD, Principal Investigator and Associate Professor, Department of Environmental & Occupational Health Sciences (DEOHS).

Timothy Larson, PhD, Principal Investigator and Professor, Department of Civil and Environmental Engineering and DEOHS.

Elena Austin, ScD, Assistant Professor, DEOHS.