Inside Beijing's airpocalypse – a city made 'almost uninhabitable' by pollution
theguardian.com
theguardian.com
> So according to these rough calculations the great smog of 1952 probably had a PM2.5 of about 700 ug/m^3, quite similar to the current Shanghai smog, and lower than levels regularly reported in other Chinese cities.
The current PM2.5 for Beijing, at http://aqicn.org/city/beijing/ , is 162 - "unhealthy".