As the main recreational open space in Boston’s Chinatown, Reggie Wong Memorial Park is vital to the neighborhood, even though it doesn’t look like much: two basketball courts and a tennis court, lined on one side by trees, wedged between on- and off-ramps for I-93.

Because of its proximity to the highway, the park is also swarming with particulates that residents can’t see, but that a new study suggests could be increasing their risk of suffering heart attack or stroke. With the Massachusetts Department of Transportation (MassDOT) looking to sell off Reggie Wong park and an adjacent parcel for development, community groups are advocating that a replacement park — which the developers will be mandated to create — address air quality concerns. They and the researchers are also calling on developers of new buildings to install air filters, to mitigate the effects of pollution.

Ultrafine particles are minuscule airborne solids created by combustion, the process powering the cars that make nearly 300,000 daily trips on I-90 and I-93, bordering Chinatown. Made up of oil, gasoline and the myriad byproducts of burning fossil fuels, ultrafine particles are so tiny — less than 2.5 microns in diameter — that once inhaled, they can easily cross from the lungs to bloodstream, where researchers believe they can cause the chronic inflammation that contributes to heart disease. While very large and fine particles are regulated by the EPA, ultrafines aren’t.

To study how health risks relate to highway proximity, researchers at Tufts University School of Medicine and Boston University School of Public Health measured ultrafine particles using a mobile lab that cruised the streets of Chinatown, Dorchester and Somerville many times over the course of a year. In each area, they then recruited hundreds of people who lived closer and farther from the highway to answer questions about their health and lifestyle, and took blood samples.

They found that exposure to ultrafine particles was in fact associated with blood biomarkers that indicate risk for heart attack and stroke, and that the closer to highways people lived, the more particles they were exposed to. About 10 percent of Americans — about 35 million people — live within 100 meters of a four-lane highway.

Doug Brugge, one of the researchers and a professor of public health at Tufts University School of Medicine, says they haven’t yet proven conclusively that ultrafine particles are causing the elevated risk, but they’re working on it. In the meantime, their research is already inspiring changes in Boston and Somerville.

“The implication is that we should be doing something to reduce exposure in housing and schools and playgrounds that are located in areas close to intense traffic sources of pollution,” says Brugge.

While conducting their research, his team hosted two planning charrettes, one in Somerville and one in Chinatown, to brainstorm tactics for increasing protection from pollution. In Chinatown, they tinkered with designs for a proposed new high school. The leading architect on that project participated, and ultimately changed his design to increase ventilation, before the school was scrapped for unrelated reasons. With MassDOT actively pushing the development of the Reggie Wong parcel, the researchers and community groups set their sites on fortifying it instead.

“The community wants to preserve the park, but there’s also, I think because of our presence and what we’ve been raising in the community, there’s a concern to do it in a way that’s more protected so that people using the park are not unduly exposed to pollution,” says Brugge.

“There’s so much traffic, and it’s right in between the on-ramp and the off-ramp, it’s a little bit obvious that that must not be a healthy place to have a park,” says Lydia Lowe, executive director of the Chinese Progressive Association (CPA), a community advocacy group and partner in the study. Lowe wants the developers who win the bid to build on the Reggie Wong parcel to consider interventions when replacing the park. Placing sound barriers, vegetation or buildings between open space and highways has been proven to somewhat mitigate the impact. Obstacles shunt the particulates upward, where they disperse. They could even put public open space on the roof of their building, Lowe laughs.

Brugge says barriers help but they aren’t perfect. They work well when wind is blowing perpendicular across the highway to the barrier, but less well when wind, wall and highway are parallel. And while they decrease particulate concentration immediately behind a barrier, they can increase concentration slightly farther away where the particulates are redirected. An ideal scenario would be for a completely clean vehicle fleet, or for parks to be located far from highways, says Brugge. Still, barriers are one of the 11 tactics the researchers recommend to cities to decrease the negative impacts of air pollution. Filtration is another, and Lowe says she’s been pleased with how many housing developers have been open to considering higher quality filtration in their new projects.

She hopes the future developers on the park site will be as open to other interventions with community benefit. The neighborhood is concerned about gentrification, about the park becoming luxury condos they don’t want.

“On the other hand, there’s a chance to get a better park and to have at least some part of that development be for affordable housing, or to get an agreement for local hiring,” says Lowe. Chinatown and the neighboring Leather District are turning up to MassDOT’s public input meetings to demand that “community priorities should be the highest determining factor of who gets to develop, not the top dollar,” says Lowe. “But I mean, that’s not usually how it goes.”

Brugge says it’s unclear to him how supportive MassDOT is of incorporating air quality protections into the new park. The agency could not be reached for comment. “I think they probably just don’t want to talk about this issue,” says Lowe.