Characterization of Regional Influence of Fine Carbonaceous Particles at Gosan, Korea

Abstract

Aims: This study aimed to study the long-range transport of anthropogenic carbonaceous aerosol at Gosan, Korea Study Design: Chemical composition of fine particles (aerodynamic diameter < 2.5㎛) and PAHs of TSP measured at Gosan during six intensive measurement periods covering four seasons. And the chemical characteristics of particulate matter were classified and compared each other according to the major source areas identified by using backward trajectory analysis in order to study the impact of distant source regions on the carbonaceous aerosol at Gosan, Korea. Place and Duration of Study: Sample: Gosan, Jeju Island in Republic of Korea, from 13 to 25 Nov. 2001, from 29 Mar. to 11 Apr. 2002, from 27 Aug. to 11 Sep. 2002, from 14 to 26 Feb 2003, from 6 to 22 Jun. 2003, and from 18 Aug. to 1 Sep. 2003. Methodology: In order to investigate the chemical composition of fine particles, 7 major ion components, 21 trace elements, organic and elemental carbon of PM2.5 were measured. In addition, particulate hazardous pollutants including 17 polycyclic aromatic hydrocarbons (PAHs) were analyzed. The measured data were classified according to the dominant source area identified with the three-day backward trajectory analysis. Then several ratios of species combining EC, OC, SO42-, K+ and PAH compounds were used to identify potential sources of carbonaceous materials. Results: Quite different characteristic in the chemical composition of fine particles was observed by regional groups of backward trajectories. Concentrations of ion components including secondary aerosol such as SO42- and NH4+ were relatively high when air masses were originated from north China. Concentrations of OC and gaseous PAHs were higher when they transported from Japan than from other source regions. High concentrations of secondary aerosols as well as particulate PAHs were observed in the air mass from north China with a higher correlation between them. Elemental carbon had a better correlation in this case not only with secondary aerosols, but also with OC and CO, implying that carbonaceous materials were originated from long-distance combustion sources. Especially positive correlation with benzo(ghi)perylene suggested that they also had a vehicular origin. Conclusion: The results showed that biomass burning and vehicular emissions mainly influenced ambient fine particles when they derived from north China and the Korea peninsula while fossil fuel combustion chiefly affected them when they originated in south China during six intensive measurement periods.