Not so quick on the draw, partner. A few months back I read a travel book by Simon Winchester (whose written some very good books. I highly recommend him) called
"The River at the Center of the World: A Journey Up the Yangtze..." written in, I'm guessing, the early 1980's or so* but it was a while back.
Anyway, Winchester, who had been to China several times before, doesn't pull any punches. The pollution he writes about -- both industrial and human (sewage) -- would make your hair stand on edge.
It wasn't until he got a good bit passed Kunming, and up to the boiling, near waterfall-like rapids at the China/Tibet border of the Yangtze that the water began to actually look like water.
Mainly, he speculates, b/c the water is so "wild" and the sheer chasms it boils through are so inhospitable that human inhabitance it well nigh impossible. Otherwise it would probably be just as polluted. And remember, this was back in the later 1970's to early 1980's. 
The moral of this post is that America, Americans, Wal- Mart, what have you didn't bring hell-with-the-lid-pried-off-pollution-right-out-of-Charles-Dicksons to China. It is a hardy perennial.
*Reissued in paperback '04