Elucidating severe urban haze formation in China

TLDR

The periodic cycle of PM events in Beijing is regulated by meteorological conditions. Reductions in emissions of aerosol precursor gases from transportation and industry are essential to mediate severe haze pollution in China. Gaseous emissions of volatile organic compounds and nitrogen oxides from urban transportation and sulfur dioxide from regional industry drive large secondary PM formation, whereas primary emissions and regional transport of PM are insignificant. We illustrate that particulate matter formation in Beijing shares similarities with other world regions but differs in efficient nucleation and extended growth, distinguishing it from typical aerosol formation elsewhere.

Abstract

Significance We illustrate the similarity and difference in particulate matter (PM) formation between Beijing and other world regions. The periodic cycle of PM events in Beijing is regulated by meteorological conditions. While the particle chemical compositions in Beijing are similar to those commonly measured worldwide, efficient nucleation and growth over an extended period in Beijing are distinctive from the aerosol formation typically observed in other global areas. Gaseous emissions of volatile organic compounds and nitrogen oxides from urban transportation and sulfur dioxide from regional industry are responsible for large secondary PM formation, while primary emissions and regional transport of PM are insignificant. Reductions in emissions of the aerosol precursor gases from transportation and industry are essential to mediate severe haze pollution in China.