Pollution of airborne metallic species in Seoul, Korea from 1998 to 2010

A comprehensive analysis was made to characterize the long-term changes in concentration of seven key heavy metal species (iron (Fe), Copper (Cu), lead (Pb), manganese (Mn), chromium (Cr), nickel (Ni), and cadmium (Cd)) bound to total suspended particles (TSP) in Seoul, Korea, from 1998 to 2010. Their mean values over this period were: 1579 ± 652, 174 ± 54.3, 63.6 ± 8.60, 46.0 ± 15.2, 11.7 ± 9.58, 9.34 ± 8.87, and 1.78 ± 0.64 ng m−3, respectively. Most of the metals exhibited a strong seasonality with maxima in spring (Mn, Fe, and Ni), winter (Pb and Cd), or fall (Cr and Cu) but minima in summer. The most prominent reductions of 71.5% (Pb) and 91.1% (Cu) were seen from early in the study period (1999-2002) to the most recent year (2010). Despite many advances in air quality, these latest concentration values were still higher than in many Western cities. It is thus still desirable to reduce their levels even further to ensure air quality improvement in the coming years.