Beijing's average concentration of PM2.5 reached 32 micrograms per cubic meter in 2023, meeting the national standards for three consecutive years, said the municipal ecology and environment bureau on Wednesday.

PM2.5 readings, a key indicator of air pollution, are a gauge monitoring airborne particles of 2.5 microns or below in diameter.

Last year, the number of days with good air quality in Beijing accounted for approximately 90 percent.

Apart from PM2.5, the readings of PM10, nitrogen dioxide and sulfur dioxide in Beijing in 2023 were 61 micrograms per cubic meter, 26 micrograms per cubic meter and 3 micrograms per cubic meter, respectively.

In comparison to 2013, last year, the annual average concentrations of PM2.5, PM10, nitrogen dioxide and sulfur dioxide in Beijing decreased by 64.2 percent, 43.6 percent, 53.6 percent and 88.7 percent, respectively.

The national capital was hit by several times by sandstorms in 2023. Air quality monitoring results from last year showed that there were a total of 30 days that were directly affected by sandstorms originating from areas outside Beijing. There were eight days with heavy air pollution, six were attributed to the influence of sandstorms.