The official Chinese government air pollution readings, found most conveniently in the right hand column here, give daily average air-quality info for many big Chinese cities. The main pollutant measured in these figures is -- to the best of my understanding -- "PM 10," which covers relatively "large" particulate matter. These are particles of up to 10 micrometers in diameter, including some large enough to darken the air and what would normally be called "dust."
What the Chinese authorities don't seem to report routinely is PM2.5. These are very fine particles, of up to 2.5 microns in diameter, which may not darken the air but are more dangerous to the lungs, precisely because they don't get filtered out in the nose or throat and instead get down deep into the alveoli. The US EPA does feature PM2.5 in its particulate measures of US air quality -- for instance, the real-time map here.
None of this is new, including the PM10 / PM2.5 omission in Chinese monitoring. What is new to me is that an unofficial monitoring station in Beijing puts out, via Twitter, hourly measures of PM2.5 readings. And after checking out the readings for earlier today I say... gacckkk, ccougghhhhh, haccckkkk.... In the columns below we have: date and time; PM2.5 reading for that time; Air Quality Index on the US scale (321 in the first one); air quality classification on US scale; and average figures for the day.
Action plan for me: I decided to skip going to the gym for a breathe-hard workout today. Action plan for US and China: no joke, working on environmental, climate, and energy matters is the most important thing that will happen during this new U.S. Administration. More on this front when I catch my breath.
Note: to avoid causing problems for some people inside China, I have slightly changed this posting from an earlier version. Anyone who notices the difference, please keep it to yourself.