maomao
普費斯
What they really need is a good, hard rain to clean the air.
Despite the fact that it very rarely rains in Beijing it could well happen. They're very good at cloud seeding to clear the air. The bluest sky I ever saw in Beijing was in 1999 for the 50th anniversary of the revolution. It had suddenly pissed down for 12 hours the day before (this almost never happens, it just doesn't rain much there).