Ambient suspended particulates in an area abutting a highway were gathered using a Partisol Model 2300 Speciaton Sampler (RP2300). Major ionic species with different particle sizes and with possible sources close to the sampling site were evaluated using Principal Component Analysis (PCA). Observational results indicate that average PM2.5 and PM10 concentrations were 66.33 and 108.28 mu g/m(3), respectively. The average ratio of PM2.5/PM10 was 62% at this sampling site, whereas the average PM2.5/PM10 ratio in this study was less than those in urban (Seoul, Korea), suburban (Basel, Switzerland) and rural (Chaumont, Switzerland) settings. Average concentrations for ionic species of NO3-, SO42- and NH4+ were 10.46, 12.63 and 7.87 mu g/m(3) in PM2.5, respectively. Average concentrations for ionic species of NO3-, SO42-and NH4+ were 17.28, 15.59 and 9.48 mu g/m(3) in PM10, respectively. Principal component analysis identified soil, secondary aerosols and marine salt as possible major pollutant sources at this sampling site. (C) 2007 Elsevier B.V. All rights reserved.