This is the third story in a three-part series on transportation-related air pollution in the Boston area. Read Part 1 here and Part 2 here.

Research from several Boston-area universities shows a kind of air pollution that can lead to heart attacks and strokes is contaminating homes and schools near highways, especially in low-income areas. But it's not just vehicles on the road that are contaminating local communities with this kind of pollution.

The research shows that planes flying in and out of Boston Logan International Airport are releasing harmful air pollution, and it's impacting surrounding communities.

"Just behind us, you know, a dozen feet, is a line of houses. This is a massive residential area," said environmental engineer Scott Hersey of the Olin College of Engineering as he stood on Bayswater Street in East Boston, looking across the water at Runways 22L and 22R at Logan. "And a couple hundred meters in front of us is this line of taxiing aircraft that's emitting a lot of gas phase pollutants and ultrafine particles."

Planes burn fuel, just like cars. So the same kind of air pollution seen near highways also exists around airports. And research on that pollution is increasingly focusing on the tiniest particles, called ultrafines, which are so small they go right into the bloodstream, leading to heart attacks and strokes. Researchers want to know just how exposed to the pollution the communities around Logan are.

Hersey and his team are working to place devices to measure that pollution in the yards of dozens of homes in surrounding communities.

"Primarily what we're doing is trying to equip the East Boston and Winthrop communities with data that they can access in real time so that they can know what the air quality conditions are like in their neighborhood at any given time," Hersey said. "So they can know whether to go to the park across the street or if they need to go across town due to air quality concerns."

One of those sensors is in the backyard of Winthrop resident Josephine Fatta. It doesn’t look like much — just a white plastic box mounted to a metal pole with a whirligig on top to measure the wind. Fatta lives in the Point Shirley neighborhood in Winthrop, a bulge in the peninsula just across from Runway 27.

"Last night when I came home around 6 p.m., it was a plane taking off every 60 seconds up until about 8:30 p.m., 9 p.m.," Fatta said.

Winthrop resident Josephine Fatta stands next to the air monitor in her back yard and points towards Boston Logan International Airport. Craig LeMoult / WGBH News

When Fatta moved here 23 years ago, she knew it would be noisy. But, she said, she didn't know about the air pollution.

"I think this is not going to get any better if it's left untended," she said. "Especially considering that there is an airport expansion happening, it's a fact. So we really need to come forward with this scientific data as ammunition against just outright unhealthy living environments."

On the other side of the airport, further south, Kevin Lane of the Boston University School of Public Health has hidden air monitoring equipment in a shed that doubles as a ticket window for boat rides from the UMass docks. The spot is perfect for measuring ultrafine particles coming from planes, as it's away from roads that could also be contributing pollution and it's directly underneath one of the flight paths.

Lane's equipment measures a spike in ultrafines when a plane flies over, and he can compare that with flight data to learn more about how elevation and wind patterns impact the community’s exposure. His research here, and the work of several other universities in the area studying the issue, is actually funded by the Federal Aviation Administration.

"The reason why we want to study ultrafine particles is because currently, they're an unregulated air pollutant," Lane said. "And some of the health studies in human population studies that myself and other researchers in the Boston area have been a part of has shown that ultrafine particles could be potentially more hazardous than some of their larger particles, such as particulate matter size 2.5, which is regulated by the EPA."

Planes on the tarmac at Boston Logan International Airport, with Winthrop in the background. Craig LeMoult / WGBH News

Flavio Leo, MassPort's director of aviation planning and strategy, doesn't dispute that ultrafine particle pollution is an issue at the airport.

"We acknowledge that we're an urban airport and that we have operations that impact local communities," Leo said. "And we want to work with the researchers and the science to work on issues like this so we can improve the information and what we know about these kinds of issues, so we can help to improve."

Leo said the expansion of Terminal E, which is expected to finish in about three years, is actually going to reduce air pollution. Creating more gates means there won't be as many planes idling on the runway as they wait for a spot to pull in.

"So by having the aircraft engines shut off, you actually have less emissions than if you have the engine running while they're off-loading and so forth," he said. "That could be an operation that could take an hour and a half, two hours."

Leo said MassPort is also putting in electric charging stations to get the airlines to switch to using electric ground crew equipment instead of diesel — although he acknowledges those vehicles make up just a fraction of the airport's emissions.

Ground crew equipment at Boston Logan International Airport is charged at an electric docking station. Craig LeMoult / WGBH News

But the scientists studying this issue locally say reducing emissions of ultrafines on the ground at Logan is only part of what needs to be done. Neelakshi Hudda of Tufts University said that's because it's not just the homes right next to the airport that are exposed. Her team went all over the Boston area looking for ultrafine particles in air samples.

"And we picked it up as far as Roxbury, as close as Chelsea," Hudda said. "And lots of places in between, where we were doing residential monitoring."

That's due to all the planes flying low over communities, especially when landing at Logan.

There is actually a precedent for MassPort addressing its impact on individual homes around the airport. Since the 1980s, they’ve invested more than $170 million on soundproofing over 11,000 homes and 36 schools in East Boston, Winthrop, Revere, South Boston, and Chelsea.

"Once there's recognition on both sides that the adverse impacts are not just limited to noise, but also you're seeing these adverse impacts on air pollution, then maybe we could do something about making homes that do reduce impacts indoors, just the way we soundproof homes now," Hudda said.

Hudda's research has shown air filtering devices called HEPA filters can cut as much as 85 percent of ultrafine particles in rooms where they're placed.

Scott Hersey of Olin College said getting MassPort to pay for HEPA filters is a "no-brainer."

"It would cost less than $1,000 per household to air-proof all of the homes, whereas soundproofing costs tens of thousands of dollars per household," he said.

However, it doesn't look like that will be happening soon. Flavio Leo of MassPort said he hopes all the research informs a new national policy for dealing with aviation-related air pollution. Once the FAA develops guidance on that, he said, Logan will take action to address it.