Researchers have identified concentrations of ultrafine particles in Bedford neighborhoods that may be connected to aircraft operations at Hanscom Field.
Dr. Neelakshi Hudda, a research assistant professor in civil and environmental engineering at Tufts University, shared preliminary findings at a virtual meeting of the Hanscom Field Advisory Commission on Tuesday.
The health implications are uncertain, Hudda said, because the Environmental Protection Agency has no models for concentrations of the particles. However, she said, there are World Health Organization guidelines, and “all the concentration numbers shown here would exceed those guidelines.” And she added, “Usually documentation of harm precedes regulation.”
Ultrafine particles “have been linked to a whole slew of health effects,” she said. “If you want to just take away one word, it’s inflammation.”
Now the researchers are looking into flight activity data to see if there are links between spikes in particles’ concentration and airfield operations, she said.
After an initial conversation several meetings ago, the four contiguous Hanscom towns as well as the Massachusetts Port Authority Community Advisory Committee chipped in to underwrite a study of ultrafine particulate matter in the Hanscom region.
Hudda said she will update her findings at the May 21 meeting of the advisory commission, and hopes her final report is ready in October. She also plans to report to the Hanscom Area Towns Committee (HATS) at a virtual meeting next Thursday.
Data collection and analysis will continue in July and August, probably at just one site in each town.
Hudda, a Lexington resident, several years ago researched the impact of aviation emissions on ground level air quality in Los Angeles and Boston. Her main area of academic interest is urban air pollution with a particular focus on transportation emissions, according to her biography on the Tufts website.
An ultrafine particle is up to 100 nanometers – Hudda said that’s about the size of a virus, “so they are really small.” The unit of measurement is particles per cubic centimeter, and in Bedford researchers found 80,000 or more. “You can fit a lot of them in a small space,” she said.
Ultrafine particles are “great markers of fresh fossil fuel combustion,” Hudda said. “They are emitted in huge numbers by jets.” Airplane exhaust is “a complex mixture of pollutants,” she said, and ultrafine particles are “one physical size-based lens to look at this complex mixture.”
“It is only one compound. It doesn’t even have any chemical breakdown,” she explained. “It’s a physical count of how many particles are below a certain size. It is the physical form of pollution that is abundantly present near airports because it is abundantly emitted from airplanes.
“Plane plumes, when they pass over a location, are few-minute long events,” Hudda explained, and it can be challenging to obtain accurate measurements of emissions. Ultrafine particles serve as “a great proxy for me to understand where the impacts of jet emissions are on ground-level air quality.” She quipped, “It allows me to look at the haystack rather than trying to look for a needle.”
The current research is conducted in two parts, since the concentrations and patterns of particles are affected by weather variables, the researcher said. Samples are monitored at three sites in Bedford, two each in Concord and Lexington, and one in Lincoln over a four-week period.
Hudda said the Bedford sampling sites, all within a half-mile of each other, but of varying distances to the runway, show higher concentrations of particles when the wind is coming from the southwest. Hudda stressed that the locations are kept anonymous.
Since the trend is similar at the three locations, “it makes me confident this a widespread phenomenon. All these sites are generally capturing that broader signal that’s prevalent in the area.”
Asked about the value of a more advanced study, Hudda said, “I think what we have is sufficient to be concerned about. But these studies take time and these studies are expensive. And starting from scratch to construct these models is not easy.”
Hudda added, “I can predict what the response would be – the FAA (Federal Aviation Administration) doesn’t have models. Nobody has models right now for ultrafine particles. But the burden of doing all this is falling on communities.”
Chris Eliot of Lincoln, chair of the advisory commission, said, “Eventually the FAA will feel that it is necessary to be funding these studies.”
Hudda noted that she also plans to submit results in response to the draft environmental impact report prepared by the developers of a proposed hangar complex at the airport near Hartwell Road.
[Editor’s Note: Updated 4/20/2024, updated the title of the Massachusetts Port Authority Community Advisory Committee.]