Johns Hopkins University researchers have published a study confirming what residents in South Baltimore’s Curtis Bay have long suspected — that the dust coating their communities comes from coal production.

The study, produced along with community leaders, found measurable amounts of the coal dust on schools, playgrounds and houses nearly a mile away from CSX’s open-air coal terminal next to the neighborhood. It has been published in the journal Science of the Total Environment.

Continuous exposure to coal dust can result in asthma, other breathing problems and lung scarring. The Hopkins team is looking into long-term human health impacts from the particles.

The Hopkins study follows a state-backed report from the end of 2023 that also confirmed the dust in the neighborhood came from coal. CSX issued a lengthy rebuttal to the state’s findings in June this year.

CSX has invested more than $60 million in its Curtis Bay Piers over the last 5 years to improve safety and dust control, a company spokesperson said in an email.

The company “remains steadfast in our long-term commitment to ensuring the safety and health” of its employees and neighboring communities, the statement said.

The Hopkins team was able to confirm the presence of coal particles using electron microscopy to analyze dust samples. They found coal dust in a sample a quarter of a mile from the CSX terminal and another one three-quarters of a mile away. The study found that coal dust levels found near the residential areas closest to the open-air coal terminal were nearly four times higher than those at two farther sites.

The paper also said that other communities facing industrial pollutants could replicate the methods that the researchers used, since electron microscopes are available at most research labs.

“There have been very few studies answering the question about community-level exposures related to coal handling and storage,” study co-author Christopher Heaney, an associate professor of environmental health and engineering at the Johns Hopkins University Bloomberg School of Public Health, said in a statement.

Co-author Carlos Sanchez, a community leader from the South Baltimore Community Land Trust, said the research confirms the worst fears of residents who have watched as a persistent black dust lands in their neighborhood.

“Our research confirms that coal dust is present at the high school I just graduated from,” Sanchez said. “I think about how quickly we measured the dust settling throughout the community, and it lines up so closely with what residents have been saying for so long. They avoid opening their windows. They give up trying to keep the siding on their homes clean.”

Kenneth Livi, an associate research scientist in materials science and engineering at Johns Hopkins, said the results prove the substance can only be coal.

“There’s coal coming out of the air. It’s not diesel fuel, and it’s not black carbon,” said Livi, who helps direct the Johns Hopkins Materials Characterization Processing facility, where the samples were analyzed. “If you want to know how bad it is for you to breathe the air, then you need to do a more detailed study, but the first pass is done.”

Maryland regulators are mulling a plan to require CSX to build large barriers in hopes of preventing the coal dust from migrating. But CSX officials have said they may not have to comply due to superseding federal regulations, and residents do not believe the walls would offer enough protection.