Thanks Keith, I've not seen stuff like that at Norwich either
Andy, I'm working down in Nanchang at the moment (in Jianxi province) and it's fine here. Apparently the smog has been very bad in Beijing for the past week or so, but it's better now after a weather front moved through and there's a good northwesterly clearing the air. I was working in Beijing last year and on some days the smog was rather dense and you could smell the smoke in it. On other days it was lovely and clear - those were the days when a cold northerly was blowing clean air down from Russia. So basically it depends on the weather. We had no problem wandering around on the smog days, but it probably wouldn't be good for anyone with asthma or similar.