BEIJING, May 17 (Xinhua) -- Beijing witnessed a 22.1-percent year-on-year drop in PM2.5 density, an indicator of air pollution, in April, the capital city's environment authority said Wednesday.
The average density of PM2.5, airborne particles smaller than 2.5 microns in diameter, was 53 micrograms per cubic meters in April, the lowest level during the same period over the past five years, according to the Beijing Municipal Environment Protection Bureau.
Beijing recorded 22 days with good air quality in April.
The bureau attributed the improvement to air pollution control measures and favorable weather conditions.
In April, the bureau issued fines totalling more than 10 million yuan (1.45 million U.S. dollars) on air pollution violations such as open fires, outdoor barbecues and construction dust.