Comparison of particulate matter characteristics before, during, and after Asian dust events in Incheon and Ulsan, Korea

This study compares characteristics of particulate matter measured in Ulsan and Incheon, Korea, before, during, and after March and April Asian dust (AD) events in the year 2002. The concentrations of PM10 just after the AD periods in Ulsan were much higher than those just before the event, during normal spring days. In Incheon, the average PM10 concentrations during the first peak period of the AD event showed a significant correlation for 24h average concentrations just before the first peak period. However, a correlation between concentrations in Ulsan was much weaker than those found in Incheon. The ratio of PM2.5 to PM10 concentrations in Ulsan during the AD event was much higher than those after the AD event. Even though there was a large increase in PM10 concentrations during the AD event compared to normal spring days, there were no large differences in concentrations Of PM2.5 between them. Concentrations of Mn, Fe, Ni, Cr, Al, Ca, and Mg extracted from the total suspended particulate (TSP) collected during the AD event were very high as compared to those after the event. However, the concentrations of Pb and Cu contained in the TSP decreased during the AD event. A comparison of ozone and PM10 concentrations during the AD events shows that extremely high dust concentrations combined with lower sunshine duration time may significantly reduce the ambient ozone concentrations. (C) 2004 Elsevier Ltd. All rights reserved.