Interesting, I was just reading an article this morning saying that researchers have been finding very dangerous air pollution levels in subways below the major cities; NYC, Boston, Philly, DC, etc..I mean off the chart levels, enough to cause upper respiratory, heart and lung issues. I wonder if all these underground explosions they've been talking about, manhole cover exposions in various places, are the tunnels being demolished and the pollution from it are seeping into the subways?? just thinking......