BEIJING — China pledged to markedly bring down PM2.5 density in key areas in 2017 in a government work report available to the media on the morning of March 5.

Sulfur dioxide and nitrogen oxide emissions will be cut by 3 percent this year, as part of the efforts to make the skies blue again, according to the report to be delivered by Premier Li Keqiang at the opening of the parliament’s annual session.

China will work harder to address pollution caused by coal burning, the report said, adding that comprehensive steps will be taken to replace the use of coal with electricity and natural gas in more than three million households.

All small coal-fired furnaces in established districts of cities at the prefectural level and above will be shut down in 2017, it said.

China will step up work on upgrading coal-fired power plants to achieve ultralow emissions and energy conservation, the report noted, adding that upgrading should be completed this year in the eastern region, next year in the central region, and by 2020 in the western region.

All key sources of industrial pollution will be placed under round-the-clock online monitoring, it said, noting that China will also strengthen research on the causes of smog to improve the scientific basis and precision of the steps taken.