'We need better air'

Chelsea, along with 11 other Massachusetts communities, has the highest asthma rate in the state.  The city’s asthma-related hospitalization rate, at 17 cases per 10,000 residents, is more than double the state average, according to the Department of Public Health.

Sixty-seven percent of Chelsea residents identify as Hispanic or Latino and the city is considered an environmental justice neighbourhood, where people face higher exposure to environmental risks. Research from Boston University shows communities of color in Massachusetts face higher levels of pollution. 

Limited tree cover and dense development contribute to higher temperatures and reduced air quality. Buildings and pavement trap heat, making some neighborhoods hotter than others. This densely populated urban heat island has more than 40,000 residents living within less than 2.5 square miles. 

On hot days, the pavement and buildings become hotter than the air temperature. Research from C-HEAT in 2021 found that temperatures in Chelsea and East Boston are, on average, about 6 degrees Fahrenheit higher than National Weather Service readings. C-HEAT is a collaboration between GreenRoots, an environmental advocacy group in Chelsea, and BU’s School of Public Health.

Between 2023 and 2025, researchers at Northeastern University also worked with GreenRoots to install more than 80 air quality sensors across Chelsea as part of iSUPER project, which alerts residents to pollution levels in real time.

“Heat and air pollution really go hand in hand,” said Madeleine Scammell, a professor of environmental health at BU’s School of Public Health. Poor air quality places additional strain on the body, she said, adding that extreme heat is often underestimated, even by healthy people. 

It’s a “silent killer,” Scammell said. “It sneaks up on you.” 

Perez's concerns about the air and heat in Chelsea extend to her aging parents, who live nearby and face increased risk of health complications during extreme heat.

Her mother, Julia Ramirez, who moved from Guatemala eight years ago, said she began experiencing respiratory symptoms and allergies after arriving in the United States.

“I never had this before I came here,” she said. “The air makes me sneeze and itch all the time. I worry about the kids, too.”

Perez’s father, Roberto Perez, who has lived in Chelsea since 1989, said the city has increased development and construction over the years.

“The construction is good because it gives more houses for people,” he said, “but the air is still important.”

He worries about his wife, who has high blood pressure.

“When it is very hot, she gets dizzy and [has] headaches,” he said, "She cannot go walking outside when it is really hot.”

Physician and professor of family medicine and community health at the University of Massachusetts, Roger Luckmann, has treated patients who experienced heat illnesses and exhaustion. He said people with pre-existing cardiovascular and respiratory conditions are among those most vulnerable to extreme heat and air pollution. He added that these cases can sometimes result in heat-related deaths, which can be difficult to track because they are often recorded under other causes.

Nearly 120,000 heat-related emergencies were recorded nationwide in 2023, according to the most recent data from the Centers for Disease Control and Prevention. As global temperatures rise, extreme heat is becoming more frequent and lasting longer. According to the World Meteorological Organization, 2024 was the hottest year on record, followed by 2025 as the second warmest.

A 2026 study conducted by researchers from the Rollins School of Public Health at Emory University found that pollution rises more in cities than in rural areas during heat waves. Air pollution particles increased by 13 percent in cities compared to rural areas. While smog levels rose by 27 percent worsening air quality and triggering short-term health complications such as asthma attacks. 

Kallejhay Terrelonge is an international student from Jamaica pursuing a master of science in journalism at Boston University. She can be reached at ktjterry@bu.edu. Ikatari Swope is pursuing a master of public health at Boston University, where she studies global health monitoring and evaluation and maternal and child health. She can be reached at Ins1018@bu.edu