title: Characterization of chemical species in atmospheric aerosols in a metropolitan basin.
abstract: Ambient PM10 aerosol samples were collected from Taiwan's Taichung metropolitan basin between October 1997 and January 1998, and their chemical characteristics studied. The average mass concentration of PM10 was 109.0 +/- 54.1 microg/m3. Carbonaceous materials, sulfate, nitrate, and ammonium were the most important contributors to the PM10 component. On average, 64% of the PM10 was made up of fine particles. During PM10 episodes, average wind speed was 0.7 m/s and relative humidity was high, 83% on average, probably giving rise to stagnation of air pollutants and their entrapment close to the surface. With relative humidity < 70%, NO3-, NH4+, SO4(2-), carbonaceous materials, and PM10 mass showed high correlation with maximum hourly average ozone (O3M). Variation in atmospheric humidity may affect the gas-to-particle interactions of S and N species. The most significant contribution to PM10 in the Taichung urban basin was from the photochemical formation of secondary aerosols and carbonaceous materials in the atmospheric environment.
authors.affiliation: Department of Environmental Engineering, National Chung Hsing University, Taichung 402, Taiwan. mtsaiyi@mail.chna.edu.tw
authors.forename: Ying I
authors.initials: YI
authors.lastname: Tsai
authors.forename: Man T
authors.initials: MT
authors.lastname: Cheng
mesh_terms: D000336:Aerosols / Q000032:analysis* / Q000737:chemistry; D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000706:statistics & numerical data; D002947:Cities; D004784:Environmental Monitoring / Q000379:methods; D008685:Meteorological Concepts; D009584:Nitrogen / Q000737:chemistry; D010084:Oxidation-Reduction; D010316:Particle Size; D025341:Principal Component Analysis; D012044:Regression Analysis; D013455:Sulfur / Q000737:chemistry; D013997:Time Factors
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D013455:Sulfur; D009584:Nitrogen