Orange-brown water flows from sinks and explodes out of fire hydrants. Protestors gather in the street with signs reading “We’re Not Lab Rats” and “Don’t Poison Our Kids.” These are some of the images from Flint, Michigan, that have occupied TV screens and newsfeeds across the country in the last few weeks. Widespread concern over the lead-poisoned water in Flint has brought to light—at least for however long the public’s attention holds—the issue of environmental justice in the national consciousness.

Outcry over the scandal was not merely driven by environmental concerns. Over half the population of Flint is Black, over 40 percent live below the poverty line, and allegations abound that racist and classist institutional priorities motivated Michigan to ignore unprecedented levels of lead and other toxins in the city’s water supply.

Meanwhile, in the low-income communities of Somerville, Boston’s Chinatown, and Chelsea, residents wake up each morning to the sound of car engines sputtering in traffic along the highway that splits their neighborhoods in half. They breathe in air that is contaminated with the kinds of particle emissions known to cause cardiovascular and respiratory diseases.

Unlike the contaminated water in Flint, the poisoned air in Somerville and Chinatown is anything but graphic: it’s largely invisible and there isn’t a clear target to blame.

This does not mean it is any less dangerous of an issue—the exact opposite it true. Particulate air pollution is listed by most sources as one of the top 10 causes of death worldwide, with over three million deaths per year attributed to it.

In the Community Assessment of Freeway Exposure and Health (CAFEH) study, Tufts professors and students have been working with community partners in Somerville and the Boston area since 2008 to collect data on air pollution, specifically the ultra fine particles that can cause cardiovascular issues.

The CAFEH study confirmed the association of ultra fine particle emissions with inflammation and cardiovascular disease. But by taking into account demographics that were collected with the data, the study also found a strong correlation between health issues caused by exposure to emissions and socioeconomic status.

Doug Brugge, the project’s co-chair and a professor at Tufts Medical School, said the project began over concern about emissions from the highways that run through certain Somerville neighborhoods.

“If you take all of the popular concerns like mercury in fish or lead in paint and measure them against particulate air pollution, it pales in impact,” Brugge said.

According to a 2010 study conducted by the Center for Disease Control and Prevention (CDC), about 4 percent of all US citizens live within 150 meters of a major highway. The study also found that the majority of the population that lives within this proximity to highways belongs to racial and ethnic minorities.

While Brugge said that subsequent connection to race was less transparent in the data collected in the Somerville and Boston areas, Lydia Lowe, co-director of the Chinese Progressive Association (CPA) and a community partner for the CAFEH study, argued that the two factors are intertwined.

“Even in Boston, a lot of people tend to see it as ‘oh, that’s class, that’s not race,” Lowe said. “It’s important to understand that race is fundamentally related to economic class issues in the US.”

When factories, power plants, and highways were being built in the 1960s and 70s, they were often constructed on the cheapest land, where the eyesore of a fume-spitting smokestack or a heavily-trafficked freeway would go unnoticed by the white voting populace that lived elsewhere. The lower-class residents whose property had to be seized through eminent domain in the name of urban renewal would be less likely to make a fuss. In other words, these projects that would largely benefit affluent white Americans would come at a great cost to low-income minority communities.

Today, environmental justice advocates are realizing that these communities weren’t only paying with their homes and quality of life—they were paying with their health as well.

“The fact that the highway is here in the first place is because of institutional racism,” Lowe said. “Because this community was seen as the place that didn’t vote, that nobody cared about, not only did we lose all these homes and have the community get broken up, but it also has been loaded for decades now with highway pollution.”

But it’s difficult to hold accountable those responsible for environmentally damaging projects like highways and factories, especially if the communities they affect are low-income. According to Natasha Soto, an organizer in Buffalo, NY, for the Clean Air Coalition of Western New York (CACWNY), this is because environmental concerns are not necessarily priorities for these communities. “They’re currently more worried about…making sure their kids have food and are going to school,” she said. “There are a lot of things that prevent folks from engaging, unfortunately.”

Organizations like CACWNY and CPA are crucial to bringing attention to environmental justice issues because they can engage, organize, and galvanize communities to become educated about how they’re being impacted by these projects and how they can hold officials accountable.

The CAFEH project has been relatively successful in this regard, according to both Lowe and Brugge, and members of the study are optimistic about achieving more in the future.

“We’ve been successful, actually, in getting some developers to change their design in a way that makes things a bit healthier,” Lowe said. “In Somerville, we actually got the city to work on an ordinance.” 

Brugge is proud of the progress the study has made for the community, but said the battle is tough, and fraught with bureaucratic, systemic obstacles. “It’s like walking uphill against a mudslide,” he said.

Interestingly, one of the reasons that any progress has been made in areas like Chinatown, where Lowe works, is because these locations are becoming increasingly gentrified. “Because they created these highways to bring people into the center of the cities, the whole trend of the role cities play is turned around and now all of a sudden everybody wants to live in the center of the city,” Lowe said. “The poor people left here are not the ones everybody cares about.”

However, Lowe also noted that this would likely lead to political pressure from the newcomers who would want to limit the presence of harmful. She said this kind of pressure is inherently more challenging for lower class and minority communities to exert. “Everyone is concerned about their health, and they care about the environment, but often if people are really struggling just to pay their rent or get a job, those issues are primary,” she explained.

It is likely that low air quality in disenfranchised communities may never be the hot, sensational topic of national discussion that the Flint crisis has become. Unlike Flint, the crisis of low air quality is a largely invisible issue. The crisis is quietly harming the health of thousands in the Boston area as people drive to work every day through the communities they unknowingly affect. And for now, the residents of these communities are still struggling to breathe.