[Observation of size distribution of atmospheric OC/EC in Tangshan, China]

Atmospheric particulate matter pollution is serious in Tangshan, a heavy industrial city of North China. The annual average concentrations of PM1.1, PM2.1, PM9.0 and TSP were (75 +/- 43), (106 +/- 63), (221 +/- 100) and (272 +/- 113) microg x m(-3), respectively, from 2009 to 2011. Carbonaceous aerosols were the key components in various size particles. Elemental carbon (EC) accounted for 9%, 9%, 6% and 4% of PM1.1, PM2.1, PM9.0 and TSP, respectively, meanwhile, organic carbon (OC) accounted for 25%, 24%, 16% and 14% of PM1.1, PM2.1, PM9.0 and TSP, respectively. The concentration spectrum distribution of particulate matter and the enrichment amount of the carbonaceous aerosols showed seasonal variations. In autumn and winter, the EC and OC concentration in the fine particulate matter reached up to (9 +/- 4), (11 +/- 5) and (19 +/- 7), (28 +/- 10) microg x m(-3), respectively, accounting for 11%, 10% and 26%, 25% of fine particles; EC and OC in spring and summer were (5 +/- 2), (5 +/- 1) and (15 +/- 3), (15 +/- 1) microg x m(-3), respectively, accounting for about 7%, 6% and 26%, 18% of TSP, respectively.