Atmospheric deposition of polycyclic aromatic hydrocarbons in an urban and a suburban area of Korea from 2002 to 2004.

Atmospheric bulk samples (wet and dry) were collected monthly during 2002 to 2004 from an urban and a suburban area in Korea for assessment of depositional flux and seasonal variations in the concentrations of polycyclic aromatic hydrocarbons (PAHs). PAH depositional flux ranged from 64.1 to 610 microg/m2/y for the urban area and from 65 to 460 microg/m2/y for the suburban area. The fluxes of PAHs measured in this study were comparable with those reported for urban and suburban areas in other countries. The fluxes of particulates and PAHs were higher in winter than in summer, consistent with the greater per capita consumption of fossil fuel in winter than in summer. Ambient temperature played a major role in the seasonal variability in PAH fluxes. Photochemical degradation of PAHs appears to occur during the summer months. The relationship of PAH depositional fluxes with major air pollutants, such as ozone, sulfur dioxide, carbon monoxide, nitrogen dioxide, and presence of particulate matter up to 10 microm in size (PM10), was also investigated. Dominant PAH compounds in both the urban and the suburban locations were benzo[g,h,i]perylene, pyrene, and indeno[1,2,3-c,d]pyrene. Based on the PAH diagnostic ratios and a factor analysis, the major sources of PAHs in the urban and the suburban regions were found to be similar. Diesel exhaust, coal combustion, and gasoline emissions contributed predominantly to atmospheric PAH contamination.