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BEIJING, Jan. 4 (Xinhua) -- Beijing saw more days with good air quality and a record-low average PM2.5 density last year, local authorities said on Monday.

The average concentration of PM2.5 in the city was 38 micrograms per cubic meter in 2020, the lowest measurement since data was first collected in 2013, according to the Beijing Municipal Ecology and Environment Bureau.

The bureau said Beijing saw 276 good air quality days last year, up by 36 days from 2019.