Severe smog has reduced the visibility of a northern Chinese city to less than half a football field.
Authorities in Harbin near the Russian border said primary and middle schools and some highways were closed Monday. At least 40 flights from its international airport had been cancelled or postponed. The official Xinhua News Agency said some buses also stopped running.
The density of fine particulate matter used as an indicator of air quality was more than 24 times higher than the level considered safe by the World Health Organization.
Also Monday, Patti Austin’s manager said the American jazz singer had been forced to cancel a concert in the capital, Beijing, on Friday evening after suffering a severe asthma attack likely linked to air pollution.