A detailed computer analysis estimated that aircraft accounted for up to 48.6% of monthly average ultrafine particle levels near Boston Logan International Airport.
Researchers modeled ultrafine particles around Boston Logan International Airport for one winter month and one summer month in 2017. They tested three aircraft emissions inventories and compared the results with measurements from seven monitoring stations near the airport.
When the model included aircraft-specific information about particle sizes, a high-detail emissions inventory estimated that aircraft contributed up to 48.6% of total monthly average ultrafine particle concentrations. The model also found different seasonal patterns, with emitted particles driving winter increases and direct emissions plus sulfur dioxide-related particle formation contributing to higher summer levels.
Seasonal particle patterns
Without aircraft-specific particle size information, the air-quality model estimated negligible aviation contributions to ultrafine particle number concentrations for all three emissions inventories. Adding that information to a high-detail inventory produced aircraft-attributable concentrations of up to 48.6% of the total monthly average ultrafine particle concentration and improved agreement with observations from seven monitoring stations.
The modeled sources varied by season. In winter, emitted particles—both particles that do not evaporate and those that can evaporate—dominated increases in ultrafine particle concentrations. In summer, direct particle emissions and new particle formation driven by sulfur dioxide were associated with about 109.7% greater ultrafine particle concentrations.
Evidence and limits
This was a computer-modeling study supported by comparisons with measurements from seven monitoring stations around Boston Logan International Airport. The simulations covered one winter month and one summer month in 2017 and used three approaches to representing aircraft emissions.
The results are specific to one airport and the periods studied, so they do not by themselves show that the same patterns occur at other airports or in other seasons. The study estimated particle concentrations and aircraft contributions; the abstract does not report health outcomes.
