I've just found this website, which may be of interest: www.ynem.com.cn
It shows pollution levels for cities and water bodies in Yunnan (national website is www.cnemc.cn)
According to this, Kunming air quality is "good", just below excellent at 51. "Excellent" seems to start at 50 and poor (or "minor contamination" as they call it) at 100. This is apparently an honest and transparent reporting of the actual situation, but then again, Beijing comes in at 58 today (!!!) while Shanghai is at 91.

Fascinating; thanks for the link. It seems to me, without any measuring, that Kunming's air is not as fresh now as it was a couple years ago. Would not be surprising in view of the proliferation of motor vehicles in that period of time.

Do you know how to navigate to older data on that Yunnan website? I could not figure out how to do it myself.

Chatting with a local today.
There is a lot of dust being kicked up by the subway/metro construction that is making things worse downtown.
This can only add to the more car thing. One good thing about Kunming is the prevailing inshore wind from the south, blowing clean air into the city. Unless of course you live below the mountains in the north.

There's actually someone who believes that the impact of the metro construction is even measurable compared to the amount of particulate matter being thrown up on the massive tracts of land that are being chai'ed and/or having developments built?

And don't forget all of the rickety, overloaded Big Blue Trucks hauling aggregate to the concrete factories in order to build all those high rises; poorly tuned, overstressed engines burning high-sulphur diesel. Yummy.

i was about to say something mildly snippy about the "subway/metro construction" compared to the frenetic chai'ing, but it appears DanTheMan has beaten me to it (and was more snippy to boot.)

that aside, i agree with the view that demolition/construction dust and car fumes are major factors in the apparent decline in Kunming's air quality over recent years.

the demolition dust issue will hopefully fade once the current phase of demolition/construction has passed (5 years? 10? they're going at it fast.) also, i understand that, while it's unpleasant to find yourself grinding them between your teeth, the large particulates in dust are not a great health risk.

the car issue i see being more of a long term risk. with 1000 newly registered cars going onto the city's roads daily, and the city's population planned to increase, we're looking at some serious emissions. couple that with Kunming's strong UV, and we can expect some photochemical wonderment. yummy.

btw. here something in english for allover China and with a bit delay but interesting nethertheless:
www.vecc-mep.org.cn/eng/

I checked this site and tried to follow one of the links. My anti-virus software kicked in because there was malware detected on the server.