SUMMERTIME CHARACTERISTICS OF AEROSOL COMPOSITION AT CHEJU ISLAND, KOREA

To understand the characteristics of air quality during summer in Nort heastern Asia, an intensive field study had been carried out at Cheju Island, Korea during the period of 20 July to 10 August 1994. Total su spended particles and PM2.5 particles were collected and their mass an d ion concentrations were analyzed. Along with PM2.5, gaseous species were collected on impregnated filters. Also, another low volume sample r collected carbonaceous species analysis. The sampling period could b e classified into two distinctive periods, with a highly polluted peri od between 20 July and 1 August and an unpolluted period between 2 and 10 August. During the polluted period, the mean non sea-salt sulfate concentrations in TSP and PM2.5 were 16.6 and 13.4 mu g m(-3), respect ively. Backward trajectory analysis showed that air parcels arriving a t the sampling site during the former period were mainly from Korea an d Japan while air parcels during the latter period were from the North Pacific Ocean. It was suggested that the air pollutant levels during the latter period could be considered as marine background concentrati ons in the region during summer. (C) 1998 Elsevier Science Ltd. All ri ghts reserved.