BEIJING, Oct. 18 (Xinhua) -- The density of fine particulate matter PM2.5 in Beijing decreased by 10.1 percent year on year in the first nine months of the year, the local environment watchdog said Tuesday.
The average PM2.5 reading in the period was 62 micrograms per cubic meter, the city's environmental protection bureau said. In 2015, the level was 80.6 micrograms, down from 95.7 micrograms in 2012.
Air quality was rated excellent or good for 155 days, 17 days more than for the same period last year. Heavy air pollution occurred for 15 days, four fewer days than last year.
Meanwhile, the density of PM10, sulfur dioxide and nitrogen dioxide dropped 14.9 percent, 28.6 percent and 6.7 percent, respectively.
Over the past three quarters, Beijing completed improvements on coal-fired boilers producing a total of 3,000 tonnes of steam per hour; eliminated 306,000 aging automobiles; and phased out 224 polluting factories.