AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
Characterization of Ultrafine Particles and Other Traffic Related Pollutants near Roadways in Beijing
Nu Yu, YIFANG ZHU, Xiaosen Xie, Caiqing Yan, Mei Zheng, UCLA
Abstract Number: 339 Working Group: Urban Aerosols
Abstract Developing countries, such as China, are facing serious air pollution issues due to their fast economic development and lack of appropriate regulations. In this study, traffic related air pollutants, such as the number concentrations of ultrafine particles (UFPs, particles with diameter < 100 nm), mass concentrations of PM2.5 and black carbon (BC) were measured near the Peking University (PKU) campus in Beijing from December 10th to 23rd, 2011. Data were collected concurrently at a roadside site and a campus site. The roadside site was located approximately 25 meters from a roadway intersection with heavy daily vehicle traffic, and the campus site was on the roof of a six-story building that was surrounded by restaurants and dining halls on campus. Meteorological data were collected from a weather station located at approximately 9 kilometers Southwest of PKU. The traffic density at the roadside site was determined from recorded video footage. No correlation was found between UFP number concentrations and PM2.5 mass concentrations. A linear correlation between BC and PM2.5 mass concentrations was found with R$^2=0.57. No apparent correlation was found between wind speed and UFP number concentrations, although strong log-decay correlations were found between wind speed and PM2.5, as well as BC mass concentrations with R$^2s ranging from 0.93 to 0.97. During the measurements, there are three days when both PM2.5 mass concentrations and UFP number concentrations were higher at the campus site than at the roadside site. This suggests there were strong PM local emission sources on campus. Diurnal patterns of PM2.5 mass and UFP number concentrations showed peaks around lunch time suggesting that the emissions may come from the surrounding restaurants and student dining halls that use Chinese-style cooking which has been associated with high UFP emissions.