Shenyang witnessed significant improvements in air quality from January to April, according to information released by the Shenyang environmental protection bureau on May 9.

By April 30, Shenyang had experienced 86 days of excellent or good air quality, 16 more days than that of the same period in 2017. Meanwhile, the days of light, middle and heavy pollution decreased two, eight and six days respectively.

In addition to the drop of ozone, the pollutant concentration of other indicators all decreased. Among which, the decreasing amplitude of sulfur dioxide reached 46.9 percent.

To continue improving air quality, Shenyang will continue to upgrade or remove coal-fired boilers.

This year, Shenyang plans to remove 365 coal-fired boilers –– 300 industrial-use boilers, and 65 standard boilers used for heating.

So far, 12 coal-fired boilers have been removed.