Fine particle measurements at two background sites in Korea between 1996 and 1997

Five intensive field measurements were carried out at two background sites in Korea; Kosan and Kangwha during spring, fall, and winters of 1996 and 19 97 to investigate the characteristics of long-range transport of air pollut ants in northeastern Asia. Fine particles (PM2.5) were collected by low-vol ume samplers and the concentrations of major ions, organic and elemental ca rbons, and nitric acid were quantified. The concentrations of anthropogenic species in PM2.5 measured at both sites were generally higher than those a t other background areas, Nagano, Japan and San Nicolas Is., USA due to con tinental outflow of air pollutants, but lower than those at an urban backgr ound site. Qingdao, China. The major components of PM2.5 were sulfate, orga nic carbon (OC), and ammonium for Kosan and sulfate, OC, ammonium. and nitr ate for Kangwha. The major fractions of sulfate at both sites are non-sea-s ails (nss) sulfate. Based on the relationship among major anthropogenic spe cies. analysis of the nss sulfate to total nitrate molar ratios, and backwa rd air parcel trajectories, it was found that fine particles measured at bo th sites during the measurement periods are mainly coming from China. At Ko san, the concentrations of anthropogenic species were higher when air parce ls were coming from southern China than when air parcels were from northern China. Ar Kangwha, however, the differences of the concentrations were not statistically significant since most air parcels were from northern China and local effects are prominent. (C) 2001 Elsevier Science Ltd. All rights reserved.