The capital's Ecology and Environment Bureau published the 2020 Beijing ecological environment report on Thursday, showing that the city's natural environment has been improving steadily.

The city's air and water quality have improved greatly, soil conditions have maintained a good state and the acoustic environment remains stable.

The average concentration of PM2.5 — fine particulate matter with a diameter of less than 2.5 microns — in the city last year was 38 micrograms per cubic meter, a year-on-year decline of 9.5 percent. It was the lowest reading since data were first collected in 2013.

The average concentration of PM2.5 in Beijing from 2018 to 2020 was 44 mcg/cu m.

Beijing had 276 days with good air quality last year, 90 more than in 2015, with no heavy pollution days.