One of my pleasures in my neighbourhood, is walking daily through Marylebone station. Its easily the most pleasant terminus stations in London. What makes it even more enjoyable to walk through is its efforts in reducing air pollution inside the station itself with the its own clean air zone. Making it the first rail clean air zone.
After a year of operation, the nano carbon filters behind the advertising hoarding on the station concourse have helped reduced pollutants like PM ( particulate matter ) and NO2 ( nitrogen dioxide ) by 70 and 75 per cent in the surrounding air, respectfully.
So while all the tube station in zone 1 have been shown to be polluted with bad air with the recent FT survey suggesting that London Underground is the dirtiest place in Central London, we have a rail air clean zone at Marylebone Station showing the way forward. By cleaning the surrounding air with its filters, it means users of the station can more easily breathe, something the tube should also try at all their stations in Zone 1.
Ultimately stopping deisel trains coming into Marylebone and replacing them with electric ones would help a lot in reducing the emissions on the concourse and the surroundings of the station.