Ambient particulate matter in a central urban area of Seoul, Korea.

The concentrations of PM2.5 and PM10 were monitored at a central urban area of Yongsan (YS), Seoul, Korea during 2013. The daily average concentrations of both PM2.5 and PM10 fractions, were 26.6±12.6 and 45.0±20.4 μg m(-3), respectively. The observed PM2.5 concentration slightly exceeded the annual standard value (25 μg m(-3)) set by the Korean Ministry of Environment (KMOE), while that of PM10 was slightly lower than its guideline value (50 μg m(-3)). Comparison of the monthly mean values (μg m(-3)) of both PM fractions showed maximum concentrations in January (PM2.5: 36.9 and PM10: 59.7) and minimum concentrations in September (PM10: 28.1) and October (PM2.5: 14.9). The existence of strong correlations between the concentrations of PM and some gaseous pollutants (e.g., CO, SO2, and NOx) indicated the commonality of contributing source processes, such as traffic and industrial emissions. The results of a back-trajectory (BT) analysis also suggests that the PM pollution in the study area is likely to have been affected by many sources such as Asian dust, volcanic emissions, and industrial activities in the surrounding countries (China, Russia, and Japan).