Air quality worsens with winter

Air quality in China improved in the first 11 months of the year, although it deteriorated in November, the national environmental authority said on Tuesday.

In the first 11 months, 80.5 percent of the days had "good" air quality, a year-on-year increase of 2.6 percentage points, but the readings of PM2.5 and PM10 - particulate matter with diameters of 2.5 and 10 microns respectively - increased in November, said Luo Yi, head of the Ministry of Environmental Protection's department of environmental monitoring.

Air quality is considered "good" when the comprehensive Air Quality Index is 100 or below.