Beijing: Tianjin Municipality, located in the notoriously smoggy Beijing-Tianjin-Hebei region, witnessed a nearly 16 percent year-on-year drop in PM2.5 density in 2015, authorities said on Wednesday.
Data released by the Tianjin municipal environmental protection bureau said the average density of PM2.5, airborne particles smaller than 2.5 microns in diameter, was 70 micrograms per cubic metres in 2015, down 15.7 percent year on year. However, it was still twice the national standard.
Sun Ren, chief engineer of the bureau, said the city's air quality has improved, with 220 days reporting air quality meeting the national standard -- 45 days more than in 2014, Xinhua reported.
Meanwhile, the density of PM10, sulphur dioxide and nitrogen dioxide fell by 12.8 percent, 40.8 percent and 22.2 percent respectively, data showed.
Yang Yong, an official with the bureau, said Tianjin has shut down 222 polluting firms and cut burning of coal by five million tonnes last year to optimise the city's energy structure.
Smog has become a major health risk in the Beijing-Tianjin-Hebei region. Local governments have resorted to restricting traffic and phrasing out backward industries to fight air pollution.
The average PM2.5 reading for Beijing also saw a year-on-year drop of 6.2 percent in 2015.