Black carbon fouls New York subway stations

Pollutant can cause breathing problems

air pollution graph

BAD AIR  Tiny black carbon particles drift through the air at several New York City subway stations. Underground stations collect the highest concentrations.  

M.J. Ruzmyn Vilcassim et al/Environmental Science & Technology 2014

Among the grit and grime cloaking New York City’s subway stations, one type of tiny, sooty particle looms large. Black carbon, an easily inhaled byproduct of burning diesel fuel, clogs the air of underground stations along several subway lines; particle levels can reach an average of seven times as high as those at the roadside, a new analysis suggests.

Researchers knew that subway air was dirty — wheels grinding along metal rails fill tunnels with steel dust, for example­ — but until now, no one had measured NYC stations’ black carbon. High levels of the fine airborne particles also have been found at subway stations in Amsterdam and Helsinki, though New York City’s stations may claim the title for most polluted, researchers report November 19 in Environmental Science & Technology.

Passenger trains in New York City use electricity, but maintenance trains still run on diesel and trigger spikes in underground black carbon levels. Breathing in too much black carbon could spark respiratory problems such as asthma.

Editor’s Note: This story was updated December 8, 2014, to correct the name of one of the subway stations in the graph.

Meghan Rosen is a staff writer who reports on the life sciences for Science News. She earned a Ph.D. in biochemistry and molecular biology with an emphasis in biotechnology from the University of California, Davis, and later graduated from the science communication program at UC Santa Cruz.

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