Scientists have found “alarmingly high” concentrations of potentially toxic particles in the air in New York City subway stations.
New York University researchers surveyed 271 platforms in December 2021 and found levels of airborne iron particles were a staggering 126 times more than the outdoor average, according to a paper published last month in the International Atmospheric Pollution Research journal.
One study shows iron, which makes up the bulk of the air pollution on the subway, can be neurotoxic if inhaled and is linked to autism, schizophrenia, and ADHD.
Another study showed a correlation between iron inhalation and cardiovascular disease, cancer, and respiratory illness, although more research is needed into the health impacts, the NYU scientists noted.
The worst station surveyed was at 181st Street on the 1 line, with an average concentration of airborne particles 17 times higher than the daily average level of metal ions the EPA considers unsafe.
It was followed by 168th Street on the 1 line; Bowling Green on the 5 line; Broadway-Lafayette on the B line, and High Street on the 3 line.
Masoud Ghandehari, the lead investigator, said even he was surprised by the level of pollution found not only on the platforms but on the trains themselves.
Nine lines — the 1, 3, 5, 6, B, C, F, M, and R — all showed average concentrations of particles higher than the EPA’s safety standard while traveling below ground, although they were about half as polluted as the platforms themselves.
The 1 train was the worst, with an average about three times higher than EPA standards.
“We expected the cars to actually be much lower,” Ghandehari said. “One does not want to be inhaling Iron particles into your lungs. . . . I’m uncomfortable knowing that there are such high levels of particulate matter.”
Commuters also took note of the thick hazy air.
“If I didn’t have to take the train I never would,” straphanger James Jean, 28, said gesturing to what he called “smog” hanging in the air of the 181st Street station, which is only accessible by elevator.
“It’s not really safe, it’s not really healthy. … sometimes trains don’t come for five or 10 minutes so you’re breathing this air in twice a day for 10 minutes at least. I’m pretty young so I’ll probably feel it in a couple of years,” Jean added.
“I don’t think anything in terms of the ventilation or circulation has changed in 10, 20 years,” said Hannah Alton, 41, while waiting on the Broadway-Lafayette platform.
Ghandehari said that air pollution on platforms was the highest when a train pulls into the station, kicking up microscopic particles as the metal wheels brake on the metal rails.
Those facing the most exposure are subway workers and others who spend long periods of time underground, he said.
MTA custodian Sean Morton, a 55-year-old who has worked at the 181st street station for more than a decade, said that although he has not felt any ill effects from the iron-saturated air, he has concerns.
“You might not feel it until five, seven years later, that’s why I’m concerned,” Morton said. “I’ve been at this station for 12 years. I’m in this sh-t longer than anybody. Anyone breathing that in, I’m getting the brunt of it.”
The union that represents MTA workers, TWU Local 100, said it would be reaching out to the city to address the issue.
“We are evaluating the study, which raises many questions, but it’s already clear that more testing and analysis is needed,” the union said in a statement. “We will be pressing the MTA on this issue and will be monitoring the situation.”
Ghandehari said that he and his team plan to do further work analyzing the air on the city’s subway system over longer periods of time, building off the snapshots his team took and analyzed in the report.
He and his team also recommended the city replace the wheel system on trains with a rubber alternative and further investigate the health impacts the iron-laden air could have.
“I think that it is for MTA to take advantage of this study and see what they can do to remedy the issues,” he said.