Up To 130% More Pollutants Found In Subway Stations Near Rivers: Study

NEW YORK CITY — A breath of air in a riverside New York City subway station could be as bad as huffing a forest fire, researchers with NYU Langone Health found.

Hazardous pollutants were up to 130 percent higher in subway stations near river tunnels than those even two or three stops away, according to the researchers' study. The levels are comparable to those seen in air from forest fires and building demolitions, researchers said.

The culprit behind the high pollution levels appears to be a quirk of New York City's geography: few other large cities with subways have such large rivers, said David Luglio, the study's lead author.

Poor ventilation in stations near water appears to create a "river-tunnel effect" that traps pollutants, Luglio said.

“This hasn’t been seen before in any other study around the world," he said.

"Some of these concentrations are quite high, they’re much higher than you’d experience in another environment."

MTA spokesperson Michael Cortez critiqued the study for, he said, only taking samples at the most active time of day. He maintained that wouldn't be an accurate comparison to EPA standards for daily exposure limits.

“We have conducted previous air quality testing in the subway system and found no health risks, however, we will thoroughly review this study as the safety of customers and employees is always our highest priority," he said in a statement.

Still, the findings come amid a slow, but steady return to subways by straphangers who largely avoided them during the coronavirus pandemic.

More than 3 million straphangers a day were in the subway during the most recent workweek, or roughly 60 percent of pre-pandemic levels, according to MTA data.

City and transit officials have consistently tried to emphasize that the subways are safe in terms of crime, but the NYU researchers' study raises questions about whether spending time in some stations — such as Bedford Avenue in Brooklyn and First Avenue in Manhattan — could have harmful health effects.

Luglio said most straphangers likely don't stay in contaminated riverside stations long enough to develop immediate repercussions, but the levels are concerning for people with asthma and other pre-existing respiratory health conditions. He said subway workers who spend hours underground also could face health risks.

The issue comes down to poor air circulation in the subways in general, and in riverside stations in particular, according to the study.

Most stations are ventilated by trains creating a "piston effect" that pushes air through the tunnels and outside through subway grates, the study found. But riverside stations and tunnels are largely underwater, leaving polluted air no place to escape, according to the study.

Luglio said MTA waterfront ventilation towers don't appear to be enough.

“Just putting a large tower doesn’t seem to mitigate it that much,” he said.

MTA crews need to prioritize cleaning efforts and increasing ventilation in river tunnels, the researchers aid.

Until then, Luglio said everyday New Yorkers should know that riding the subway is still better for the planet than driving a car. He said straphangers concerned about pollution can be protected by a now-familiar tool: a face covering.

“It’s just a way to protect yourself," he said.