Latest stats from the city's Environmental Protection Bureau show the number of days with high air quality reached 57 in the first four months of 2015, up eight days from a year earlier.
During the period, the number of days with severe air pollution decreased 42 percent year on year.
Meanwhile, the concentration of sulfur dioxide and fine particles less than 2.5 microns in diameter was reduced by about 43 percent and 19 percent, respectively.
The Chinese capital, along with its neighboring Tianjin Municipality and Hebei Province, has suffered from severe air pollution for years, with excessive coal use and car emissions among the key culprits.
Amid the country's stepped-up campaign against pollution, the th
