Study on the Status and Distribution of Ultrafine Particles During Beijing Olympics in 2008

Abstract

PP-30-011 Background/Aims: The air quality during Beijing Olympics in 2008 had been dramatically improved. The aim of this study is to explore characteristics of the size distribution and ambient behavior of fine and ultrafine particles (UFPs) during the Beijing Olympics and the influential factors to number concentration of UFPs. Methods: The monitoring has been performed in Beijing, China during 31 July 2008–8 September 2008. Using Ultrafine Particle Monitor Model 3031 produced by US TSI incorporated to monitor the daily number concentration of 20–500 nm particle matter, then use Excel 2003 and SPSS 13.0 to arrange and analyze the data of the monitoring. Results: During the Olympics, the mean value of the 20–100 nm particulate matter's number concentration is 5920.43/cm3. The 30–50 nm particles contributed to the largest portion of all size resolutions. There are 2 peaks showed on the curve of 24 hours' number concentration of 20–100 nm particles, which are at afternoon and at evening, respectively. Conclusion: This paper indicates that the number concentration of ultrafine particles showed considerable reduction in the 2008 Olympics compared to the pre-Olympics years. In Beijing and in the developed country, the different size resolution of the particles, which contributed to the largest portion of 20–500 nm particle matter, indicated that the sources of the particles may be different in these 2 places. And the observations of the curves indicated that the number concentration of the UFPs is related to the traffic volume and photochemical reaction. Also there are significant correlations between number concentration and temperature as well as relative humidity.