Air pollution in London is far better than it was last century but that's not to say there isn't room for improvement. Like it or not air travel is here to stay and despite a recent lull in capacity it will continue to grow. It's one of the things that makes London an international city. I tend to favour Boris' suggestion of a new airport in the Thames Estuary but I don't think that's not going to come at a big price. Many people will be staying awake at night worrying about the new transport links to make it viable, the upheaval that it causes, environmental damage, job losses at Heathrow and so on. There isn't an easy solution except that quieter and less polluting aircraft will make the pill easier to swallow.