Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published February 2011 | public
Journal Article

Sources of excess urban carbonaceous aerosol in the Pearl River Delta Region, China


Carbonaceous aerosol is one of the important constituents of fine particulate matter (PM_(2.5)) in southern China, including the Pearl River Delta (PRD) region and Hong Kong (HK). During the study period (October and December of 2002, and March and June of 2003), the monthly average organic carbon (OC) ranged from 3.52 to 7.87 µg m^(-3) in Hong Kong and 4.14-20.19 µg m^(-3) in the PRD from simultaneous measurements at three sites in HK and four sites in the PRD. Compared to the PRD, the spatial distribution of carbonaceous aerosol in Hong Kong was relatively homogeneous. Sources contributing to excess OC in the PRD were examined, which is the difference between OC concentrations measured at the PRD sites to the average level in Hong Kong. Eight primary sources contributing to excess OC were identified with chemical mass balance modeling in a combination with molecular markers analyzed by gas chromatography/mass spectrometry. Excess OC at Guangzhou, the capital city of Guangdong province, was consistently high, ranging from 9.77 to 13.6 µg m^(-3). Four primary sources including gasoline engine exhaust, diesel engine exhaust, biomass burning, and coal combustion accounted for more than 50% of excess OC in the PRD, especially in December (up to 76%). Mobile source emissions alone can contribute about 30% of excess OC. The unexplained or other excess OC was the highest at the rural site, but in general less than 20% at other sites. The coal combustion source contribution was unique in that it exhibited relatively homogeneous spatial distribution, indicating it was still an important source of carbonaceous aerosol in the PRD (17% of excess OC) during the study period. This analysis revealed that primary emissions are important sources of excess OC in the PRD and there is a need to reduce the emissions of mobile sources, biomass burning, and coal combustion in order to improve air quality in southern China.

Additional Information

© 2010 Elsevier Ltd. Received 25 April 2010; revised 2 September 2010; accepted 18 September 2010. Available online 27 September 2010. This research was sponsored by Hong Kong Jockey Club Charities Trust, Castle Peak Power Co. Ltd., the Environmental Protection Department of the Hong Kong Special Administrative Region, the Shell Hong Kong Ltd., through Civic Exchange. We thank Christine Loh, the founder of Civic Exchange, and C.S. Kiang for coordinating the project, Dr. Tao Wang of Hong Kong Polytechnic University for the project assistance throughout this study, and Tao Liu of the Guangzhou Environmental Monitoring Center, Jianjun Chen of the Conghua Environmental Monitoring Center, and Wendong Yang of the Zhongshan Environmental Monitoring Center for their assistance in sampling coordination. We thank two anonymous referees for their valuable comments and constructive suggestions to the manuscript. While one of the coauthors, G. Hagler, is currently identified as an U.S. Environmental Protection Agency (USEPA) employee, the data were collected while she was a doctoral student at the Georgia Institute of Technology. This article has been subjected to the USEPA and HKEPD technical and administrative review process and approved for publication. The content of this paper does not necessarily reflect the views or policies of any governments, including USEPA, the Governments of Guangdong and the Hong Kong Special Administrative Region, nor does any mention of trade names or commercial products constitute an endorsement or recommendation of their use.

Additional details

August 22, 2023
October 23, 2023