[Size distribution and characterization of OC and EC in atmospheric aerosols during the Asian Youth Games of Nanjing, China].

Aerosol samples were collected by an Andersen cascade impactor (Andersen) in Nanjing during the Asian Youth Games (AYG), and organic carbon (OC) and elemental carbon (EC) in particles were determined by DRI Model 2001A carbon analyzer of USA. Observations indicated that OC (51.55%) and EC (54. 81%) were enriched in the fine aerosol particles with size below 1. 1 μm, the highest mass concentrations of OC and EC were located at 0-0.43 μm and 0.43-0.65 μm, respectively, accounting for 20. 90% ±5.02% and 22. 68% ±9.90% of the total concentration. The mass concentrations of OC and EC in PM1.1, PM1.1-2.1 and PM(2.1-10) during AYG period were decreased by 43. 44% -56. 17% and 59. 17% -73.55% as compared to the values before AYG. The spectral distribution of OC was bimodal during the whole observation period, while the spectrum distribution of EC was changed from bimodal to unimodal. OC and EC during the observation period were in good homology. OC and EC were attributed to automobile exhaust fumes before AYG. During AYG, OC and EC in PM1.1 were mostly from automobile exhaust fumes, while OC and EC in PM1.1-2.1 and PM2.1-10 were from automobile exhaust fumes and coal combustion.