Research fellows have found the main source of particles with a diameter of less than 2.5 microns in the Beijing air is fossil fuel combustion emissions,  Xinhua reported Monday.

A research team at the Institute of Atmospheric Physics in the Chinese Academy of Sciences found six sources: soil dust (15 percent), coal burning (18 percent), biomass burning (12 percent), vehicle gas emissions and garbage burning (4 percent), industrial pollution (25 percent) and secondary inorganic aerosols (26 percent).

Coal burning, industrial pollution and secondary inorganic aerosols combine to form fossil fuel combustion emissions, a total 69 percent of pollutants.

Researchers analyzed samples mainly in downtown Beijing through 2009 and 2010.

In winter, researchers found coal burning was the main culprit. Biomass burning stepped up in spring and fall.

The rapid development of industry around Beijing contributed to the trans-regional pollution transmission.

To combat air pollution, researchers suggest Beijing improve its energy structure as well as cooperate with other regions.

Global Times