TIANJIN, Jan. 14 (Xinhua) -- North China's Tianjin Municipality saw a decline in the density of hazardous fine particle matter PM 2.5 in 2018, the mayor of Tianjin said Monday.

The city's average PM 2.5 density dropped to 52 micrograms per cubic meter in 2018, down 16.1 percent, according to the annual government work report delivered by Zhang Guoqing at the opening meeting of the annual session of the Tianjin Municipal People's Congress.

To fight smog and lower the density of PM 2.5, the city has taken measures such as overhauling polluting factories, monitoring emissions from vehicles and planting 25,333 hectares of trees in 2018.

According to the report, Tianjin will continue to battle smog by promoting clean energy heating, vowing to further lower PM 2.5 density in 2019.