Also thanks to the 2008 Olympics. They made a massive difference cleaning up Beijing and improving air quality for that event.
Edit: I wrote that before reading the article, and the article seems to be claiming that it was still bad even for the Olympics and a few years afterwards which is contrary to what I remember. I visited in 2009 and it was very clean and clear.
You need to look at the DNS server used by whatever client is resolving that name. If it's going to an external recursive resolver instead of using your own internal DNS server then you could be leaking lookups to the wider internet.