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Abstract: Six unique OH-reaction products of naphthalene and phenanthrene were detected and quantified in ambient PM2.5 collected in Seoul, Korea between 2006 and 2007. The range of annual average concentrations of six reaction products, 2-formylcinnamaldehyde, phthalic acid, phthalide, dibenzopyranone, 9-fluorenone, and 1,2-naphthalic anhydride extended from 2.45 to 49.9 ng m−3 and all of these values were higher than the average concentration of single particulate PAH compounds in Seoul, Korea. The seasonal pattern of six reaction products generally showed higher concentrations in winter months than in summer months. This indicates that the formation of these compounds by atmospheric photochemical reactions is significant both in winter and summer and that enhanced primary sources and higher particle to gas partitioning activity due to lower ambient temperature may contribute to the high concentrations of these compounds in the winter months in Seoul, Korea. The high correlation of the formation of 2-formylcinnamladehyde and dibenzopyranone with the estimated SOC concentration, suggests that the formation of SOA from gas phase PAH reactions in the real atmospheres is significant. Also, we suggest that (E)-2-formylcinnamaldehyde and dibenzopyranone could be used as unique indicators for the atmospheric oxidative reactions of naphthalene and phenanthrene, respectively. [Copyright &y& Elsevier]

Abstract: To identify the ambient characteristics of a mega city in Northeast Asia, the particulate PAHs in TSP were measured for 18months at Seoul, the capital of Korea. The average concentration of the ambient particulate PAHs at Seoul for the sampling period was 26.6±28.4ngm−3 with the range from 1.57 to 166ngm−3. It showed winter maxima and summer minimum mainly due to the increased fuel consumption in winter both at Seoul and Northeast Asia. The ambient level of PAHs in Seoul was lower than the cities in China but higher than other urban areas. The stronger relationship between the ambient particulate PAHs concentrations and the inverse of the ambient temperature (1/T) at Seoul compared to Gosan, a background site in Korea and the difference of the distributions of BeP/BaP ratios at Seoul and Gosan might be due to the characteristics of Seoul which was governed by both transport from outside and local emissions. The relationship between the particulate PAHs concentration and (1/T) can be used as an indicator for those two factors for Seoul. [ABSTRACT FROM AUTHOR]

Abstract: Polycyclic aromatic hydrocarbons (PAHs) in both gas and total suspended particles were measured at Gosan, Jeju Island in Korea, a remote background site, for 15 days (March 29–April 12, 2002). During the sampling period, a severe three-day Asian dust (AD) event originating from Mongolia and northern China was observed throughout the Korean Peninsula and Jeju Island. In addition, pollution (PO) and normal (NO) periods were also identified based on the levels of anthropogenic pollutants. Despite a large difference of PM10 concentrations between the AD and PO periods, the levels of particulate PAHs in both periods were comparable (2.7±1.0 and 2.4±0.5ngm−3, respectively) since they were determined by the concentration of anthropogenic PM2.5 transported from industrial areas of China. In the AD period, the level of gaseous PAHs, which were mostly from local sources, was the lowest due to strong winds; the gas/particle partitioning was close to equilibrium as the effect of long-range transport was manifested. The results of backward air trajectories, correlation analysis, and diagnostic ratios show that long-range transport of particulate PAHs produced by coal/biomass burning in China could strongly affect the levels and patterns of PAHs at Gosan, Korea. [Copyright &y& Elsevier]