China smog emergency shuts city of 11 million people

Unhealthy in the extreme:

“An index measuring PM2.5, or particulate matter with a diameter of 2.5 micrometers (PM2.5), reached a reading of 1,000 in some parts of Harbin, the gritty capital of northeastern Heilongjiang province and home to some 11 million people.

A level above 300 is considered hazardous, while the World Health Organisation recommends a daily level of no more than 20.”