By Tyler Haughn
Despite mounting evidence that noise barriers can limit exposure to air pollution caused by traffic passing through Interstate 93, significant challenges remain before Somerville can begin building them.
Noise barriers are large structures designed to absorb traffic-related noise and have been found to decrease air pollution as well. There are two kinds: absorptive and reflective. Absorptive sound barriers disperse sound within its panels with little to no sound reflecting off the barrier. Reflective walls perform a different function by bouncing the sound back to its original direction.
When Interstate 93 was first constructed during the 1970s, Massachusetts promised to build noise barriers to mitigate the pollution levels. That agreement never came to fruition, except for one small segment of noise barriers that were set up in the Ten Hills neighborhood as part of the Northern section of Interstate 93 near Assembly Row.
Multiple communities still have no protection from the harmful pollution along the busy highway. This includes sections of east Somerville, Winter Hill and Somerville Housing Authority’s Mystic River Development.
The Somerville community has been demanding that the state fulfill its past promise by erecting noise barriers to protect the city’s most vulnerable residents from air and noise pollution. This push for noise barriers is being spearheaded by a group of community stakeholders, researchers and elected officials.
The Community Assessment of Freeway Exposure and Health Study (CAFEH) has prioritized studying the viability of placing noise barriers along Interstate 93 to reduce air and noise pollution in Somerville. Ellin Reisner, who serves as president of the Somerville Transportation Equity Partnership, supports this initiative but understands there will be challenges.
“It becomes more complicated on other parts of I-93 in Somerville because there isn’t the ability to put a continuous barrier on part of the roadway that goes from Temple Street up to the Medford border,” Reisner said.
CAFEH lead researcher Doug Brugge is directing a community process that studies the potential benefits of building noise barriers near Interstate 93. The findings suggest noise barriers are not only useful for reducing overall traffic noise but can also help decrease exposure to roadway air pollution. The noise monitoring study also found that sound levels next to Interstate 93 surpass regulatory and health-based standards.
“Noise barriers can work if the configuration of the highway in the neighboring communities is right,” Brugge said. “For the East Somerville neighborhoods, it looks like a noise barrier can be quite helpful.”
CAFEH has gone on to produce detailed assessments of four different sites along Interstate 93 to determine if they are suitable locations for noise barriers. These include Mystic Housing, States Avenues, Ten Hills and Boat House and Foss Park.
As things stand, the Massachusetts Department of Transportation (MassDOT) has no plans to install any noise barriers in Somerville. MassDOT follows a specific set of guidelines when determining eligibility for new barriers. These criteria are divided into two categories: Type 1 projects and areas that are part of MassDOT’s Priority List.
MassDOT does not take air pollution into account when deciding if sound walls are needed. The only factor that is considered is the amount of noise being generated by a highway.
Brugge said efforts currently underway in the state legislature can hopefully be successful soon.
“That’s probably what’s going to be necessary because it’s very hard to do it on a local level,” Brugge said.
There is momentum growing around Somerville for sound barriers to finally be introduced. Reisner has been working closely with state representatives Mike Connolly and Christine Barber to bring more exposure to the issue. Both officials recently secured a $2 million transportation bond authorization bill to build sound walls along Interstate 93. However, there is one caveat to the allocation: MassDOT and Governor Baker must give the green light before the funds can be utilized.
The Massachusetts House of Representatives introduced a budget amendment back in April that secured $30,000 for a study to look into decreasing air and noise pollution in Somerville.
“It’s not just that we’re advocating for it,” Reisner said. “We’re really trying to come up with solutions.”
John Durant, an environmental engineer at Tufts University, said a major obstacle in the way of building noise barriers is the high cost involved.
“The only real way to address air and noise pollution is to spend a lot of money,” Durant said. “The only technology that seems to work is sound barriers and those are very expensive.”
Durant said noise barriers can cost $10 million per mile depending on the location and size. Another challenge is finding technology that is the right match for the surrounding community.
“This is a tricky one because everyone has a different sensitivity to noise,” Durant said. “Right now, I think the best technology for that is sound walls. They’re just very expensive and very politically charged.”
Durant has collaborated with Brugge and Reisner on the CAFEH air pollution studies. He is a trained environmental engineer who is primarily responsible for monitoring air pollution levels along Interstate 93. He does this by driving around in an electric Chevy Bolt equipped with modern technology to record pollution levels.
“We have a suite of rapid response instruments, which measure the same pollutants as the stationary sites but does so as the vehicle moves along,” Durant said. “It makes measurements so you get a good sense of the spatial variation of pollution in neighborhoods near busy roadways.”
The vehicle is full of computer equipment and a fan is used to bring in air from the outside. Seated next to Durant in the passenger seat is a laptop that shows the fluctuating air pollution outside depending on the location. Durant regularly drives this mobile laboratory along Interstate 93 near Somerville. This and other research generated through the CAFEH studies have found that ultrafine particles are most prevalent near highways.
Durant said he is particularly concerned by the excessive levels of ultrafine particles that Somerville residents are being exposed to. Research shows that ultrafine particles can cause cardiovascular problems such as heart attacks and strokes. They can cause debilitating neurological effects as well.
“People living near busy roadways and highways are exposed to high levels of ultrafines,” Durant said. “There’s a lot of them, and they can get into your lungs and stay there. They can also get into the blood system and get distributed throughout the body.”
Durant said it is critical that funding remains available so researchers can continue analyzing different mitigation measures with the ultimate aim of reducing pollution for near-highway populations.
Durant said he strongly believes this involves an overhaul of construction practices so land developers can be a part of these changes.
“Boston is a crowded city,” Durant said. “There’s less open space for development so a lot of developers are putting in very expensive to moderately expensive housing near busy roadways. That community needs to be alerted to the fact that there are unique exposures in terms of air pollution and noise near roads and those buildings.”
Durant says it is high time developers prioritize building in locations that will avoid creating an unequal distribution of pollution. In addition to erecting noise barriers, this could prove to be another important pathway towards a more equitable environmental future.
“The people who live near the roadways are the ones who are bearing the brunt of the air pollution and the noise,” Durant said. “There’s a lot of low-income housing and a lot of people who have lesser means for whatever reason, whether they’ve been redlined to specific areas historically or whatever it may be. They have been subjected to pollution, not of their own making, by cars that are just passing through town. So the regulatory community needs to be made aware of these inequities.”
Despite the monumental challenges, Reisner still wants to see these 30-foot walls eventually raised to help protect her community from the dangers of ultrafine particles and other pollutants.
“It is a major concern for people,” Reisner said.