Characteristic variation of PM10 in Seoul, South Korea during 2000-2005

PM10 along with O3, CO, SO2 and NO2 has been monitored at 13 stations in Seoul, the capital of South Korea. During 2000-2005, annual PM10 mean concentrations were increased until 2002 and then decreased. While Asian dust events were the most frequent in 2001, in 2002, the highest concentrations of PM10 were recorded nationwide. The effect of Asian dust on PM10 is evident in monthly variations, in which PM10 concentrations were the highest in March and April. Except these two months, the second maximum PM10 was found in June, when O3 levels in exceedance of National Air Quality Standards were the most frequently observed. PM10 concentration was the lowest in August, which is mainly due to heavy rains during summer monsoon. Particularly, monthly PM10 concentrations were very well correlated with the frequency of westerly wind. On the other hand, the percentage of easterly wind was negatively correlated with PM10, leading to the lowest concentration in August and September. These temporal distributions of PM10 will be fully understand to implement policy for PM10 abatement in Seoul.