| PM2.5 samples were taken at Xinan University in Beibei District, Chongqing Academy of Environmental Sciences, the government of Dadukou District in august of year 2004 to May of year 2005, and analyzed for organic carbon (OC), elemental carbon (EC), inorganic elements, water-solubility ions by Elemental Analyzer, X-ray fluorescence Spectroscopy Analyzer, Ion chromatography Analyzer, respectively. Organic carbon (OC), elemental carbon (EC), inorganic elements, water-solubility ions in PM2.5 and relationship between some components of PM2.5 were investigated in this work. And also it discussed source apportionment of PM2.5 by factor analysis (FA) in Chongqing. Followed is the main conclusion that thesis has got: that:①The seasonal and weekly variation of PM2.5 mass concentration are distinctive. It is high in winter and low in summer. But in few spring weather, the pollution of PM2.5 is serious and came out the highest value of 104.8μg/m3, 79% of the PM2.5 mass concentrations have exceed the standard in spring at the site of Beibei though its mass concentration is much lower than Dadukou, the pollution of PM2.5 is serious in Chongqing;②The anthropogenic elements and crustal elements are the dominant elemental species in PM2.5. In the study of the water-solubility of PM2.5 at Chongqing , sulfate, ammonium, kalium and calcium were found to be the dominant ionic species of PM2.5, which accounted for about 23.34% of PM2.5 mass in total. The other inorganic ions(Br-,Cl-,NO3-,Na+ ect) accounted for about 2.1% of PM2.5 mass, and the concentration level changed from 0.11 to 0.94μg/m3.③The concentration of SO42- reached the highest level in summer, while the concentrations were low both in spring and autumn and reached the same level. The concentration of NO3- was high in the winter, following the spring and autumn, and it has a large change. The concentration of NH4+ has the same change with SO42, summer and winter reached the highest level while spring and autumn came down the lowest level of the whole year. The correlation coefficientbetween SO42-,NO3-and NH4+ in PM2.5 were good and may suggest the similar forming process of these ions.④Compared with the study result of the other foreign counties, the OC/EC in PM2.5 of Chongqing was close to some of the foreign cities, however the absolute value of OC/EC were on the high side distinctly: the value of OC/EC(4.7) exceeded 2,it said that the OC of Chongqing belongs to secondary pollution source. ⑤PM2.5 samples were continuously collected at three locations in Chongqing , and elements ,water soluble ions, and carbonaceous species were measured .Organic material was the most abundant species in PM2.5,with a mass percentage of 22.85% and 33.3% at Beibei and Dadukou, respectively. It was followed in decreasing order by secondary inorganic particles, soil dust, elemental carbon, and trace elements. About 24% of PM2.5 mass was not identified in the three sampling sites.⑥The principal component analysis was used for studying the source apportionment at three sampling sites of Chongqing, the result suggested that the main source of PM2.5 are the dust from soil,soot and metal smelting, and the exhaust gases. The influence of traffic is becoming more and more important.
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