BEIJING — Beijing saw the reading for a primary air-pollution index fall 33.3 percent year-on-year in the first two months of this year, official data showed.

The city's average concentration of PM2.5 was 34 micrograms per cubic meter in the January-February period, said the Beijing municipal ecology and environment bureau.

The city reported no severely polluted days in the two months.

During the Beijing Winter Olympics period from Feb 4 to 20, the city's average PM2.5 reading stood at 23 micrograms per cubic meter.

The PM2.5 reading is a gauge monitoring airborne particles of 2.5 microns or less in diameter, which can penetrate deep into people's lungs and pose serious health risks.

Beijing made a breakthrough in its air pollution control last year as the city reached the national air quality standard. The city's average concentration of PM2.5 was 33 micrograms per cubic meter in 2021, the lowest level since records began in 2013.