This study was carried out to elucidate the chemical compositions of water-soluble inorganic ions in PM10 and PM2.5 aerosols collected during summer and winter in downtown Jejusi city. The ratios of NO3 - to the total mass of ionic species in PM10 and PM2.5 aerosols largely increase in winter compared to summer, while SO4 2- ratios in both aerosols appear to follow the opposite trend. Moreover, concentrations of Na+, Mg2+, Ca2+ and Cl- in PM10 and PM2.5-10 aerosols are higher in winter than in summer. The nitrate concentrations in PM10 and PM2.5 aerosols increase with an identical increase in excess ammonium during winter, however, nitrate formation during summer is not important owing to ammonium-poor conditions.

Abstract
 1. 서 론
 2. 연구 방법
  2.1. 시료의 채취
  2.2. 시료의 분석
 3. 결과 및 고찰
  3.1. 미세먼지의 질량농도
  3.2. 미세먼지 조성특성
 4. 결 론
 REFERENCES

• 이기호(제주대학교 환경공학과) | 이기호.
• 김수미(제주특별자치도 보건환경연구원) | Su-Mi Kim (Research Institute of Health & Environment, Jeju Special Self-Governing Province)
• 허철구(제주대학교 환경공학과) | Chul-Goo Hu (Department of Environmental Engineering, Jeju National University) Corresponding author