Ultrafine Metal Concentration in Atmospheric Aerosols in Urban Gwangju, Korea

PM10, PM5, and ultrafine (< 0.132 μm) mass concentrations, and metals (As, Be, Ca, Cd, Fe, K, Mn, Ni, Pb, Sb, Se, and Zn) in ultrafine particles were determined in urban Gwangju, Korea during the sampling periods of 4/2/2007-4/20/2007 in spring, 8/2/2007-9/12/2007 in summer, 11/19/2007-12/2/2007 in fall, and 1/16/2008-2/3/2008 in winter. Data showed that PM10 mass concentration was the highest in spring due to the contribution of long-range transported and fugitive dust particles, whereas mass concentration of ultrafine particles had no seasonal variation and was not significantly affected by dust particles. Enrichment factor (EF) for each metal and Principal Component Analysis (PCA) among ultrafine metals were conducted to evaluate effects of anthropogenic and natural sources on ultrafine metals and to determine association among metals. We found that Fe, Ni, Zn, Sb, and K exhibited relatively higher fraction in ultrafine size and had higher EF values (i.e., anthropogenic). Results from wind-dependent metal concentrations suggested that Zn and Ni in ultrafine particles originated from metallurgical sources from a nearby industrial complex. We also found that during an Asian dust event, Ca concentration increased most significantly among ultrafine metals.