Study shows New York subways have a pollution problem

In the Big Apple, even mass transit can be a pollution risk.

According to a study published Wednesday in the journal Environmental Health Perspectives, New York's subways are the most polluted in the Northeast -- and one subterranean station has higher levels of particulate pollution than any other station in the world. The study, conducted by researchers from NYU Langone's Department of Environmental Medicine with assistance from researchers in Connecticut and Alabama, measured particulate matter and carbon pollution during morning and evening rush hour in 71 stations across four metropolitan centers in the Northeast: Boston, Philadelphia, Washington, DC, and New York. The researchers measured pollution on station platforms, in the ambient environment outside the stations, and on trains while riding between stations.