'People should be alarmed': air pollution in US subway systems stuns researchers
Tiny airborne particles, probably thrown up by train brakes or the friction between train wheels and rails, are rife in the 71 underground stations sampled by researchers during morning and evening rush hours in Boston, New York City, Philadelphia and Washington DC, the cities that contain the bulk of subway systems in the US.
The researchers calculated that someone making a typical commute to and from Christopher Street [NYC] was increasing their risk of an adverse cardiovascular event by 10%. But the station wasn’t the only one with elevated airborne toxins, with Broadway in Boston, Second Avenue in New York City and 30th Street in Philadelphia among the most polluted stops in the US north-east.
Still, Boston's subways are better than NY and NJ's.