BEIJING - More vehicle-cleaning machines will be installed at construction sites in Beijing this year to help reduce dust emissions.

"Dust from construction sites and roads is a major contributor to fine particle pollution, or PM 2.5, in the air," said Yao Hui, deputy director of the Beijing Municipal Environmental Protection Bureau. Some 15.8 percent of PM 2.5 in the air comes from dust, he said.

PM 2.5 (fine particulate matter 2.5 microns or less in diameter)?is a major cause of haze and can be harmful to health.

Beijing plans to cut PM 2.5 levels by 15 percent in 2015 compared with 2010 levels, and to cut overall air pollution levels by 30 percent over the same period, according to the city's work plan.

Currently, Beijing has some 180 million square meters of buildings under construction. Eight subways are also being built, adding more pressure for the government to cut down the concentration of PM 2.5.

In 2011, 76 cleaning machines were installed at pilot projects in Beijing to prevent vehicles leaving construction sites from spreading dust.

"More sites will have such machines this year, thus keeping the dust emission from vehicles under control," said Wei Jixiang, an official with Beijing Municipal Housing and Urban-Rural Development. "Developers can buy or rent them according to their economic situation."

Wei said dirt that is removed from the vehicles will be allowed to settle in ponds near the machines; the waste water will then be discharged into the storm drain system.

Construction vehicles also contribute to trash along the sides of roads, which generates dust in the air. Vehicles which discharge trash will face severe fines.

"Many departments are conducting multiple measurements to reduce dust and control the PM 2.5 pollution," Yao said, "We'll continue to do more."