Black carbon size distribution and mixing state in urban environments

Black carbon (BC) is a component of particulate matter that has gained recognition in recent years for the effect on the climate (Jacobson, 2001), and the association with adverse health effects (WHO, 2012). It plays a role in influencing monsoon patterns and cloud formation; increasing snow and ice melting rates; and raising the average sea level. Once BC is emitted from sources it undergoes physical changes but is considered stable. The size of carbon particles that originate from diesel combustion may differ from those generated by biomass combustion or from coal burned in power/heating plants and for residential cooking and heating. This study presents a direct and continuous measurement of atmospheric BC mass size distribution in roadside of a busy roadway. The results demonstrate the evolution of BC mass size distribution in different stages of lifetime in urban environment.