I'm hoping the aircon filters will start clearing the filthiness of the tube air. Something tells me they'll have to change them more often then think.

Once you see it, you can't unsee it. There's this dark mist in the London underground, I find it very visible on the northern line, around elephant and castle. Just standing at one extreme of a platform and trying to look at the farthest part of the station, you'll realise everything is "foggy" by lack of a better term.

One hour there would turn my snot black.