@article {HAGLER20063802,
	title = {Source areas and chemical composition of fine particulate matter in the Pearl River Delta region of China},
	journal = {Atmospheric Environment},
	volume = {40},
	number = {20},
	year = {2006},
	pages = {3802 - 3815},
	abstract = {Fine particulate matter (PM2.5) was measured for 4 months during 2002{\textendash}2003 at seven sites located in the rapidly developing Pearl River Delta region of China, an area encompassing the major cities of Hong Kong, Shenzhen and Guangzhou. The 4-month average fine particulate matter concentration ranged from 37 to 71μgm-3 in Guangdong province and from 29 to 34μgm-3 in Hong Kong. Main constituents of fine particulate mass were organic compounds (24{\textendash}35\% by mass) and sulfate (21{\textendash}32\%). With sampling sites strategically located to monitor the regional air shed patterns and urban areas, specific source-related fine particulate species (sulfate, organic mass, elemental carbon, potassium and lead) and daily surface winds were analyzed to estimate influential source locations. The impact of transport was investigated by categorizing 13 (of 20 total) sampling days by prevailing wind direction (southerly, northerly or low wind-speed mixed flow). The vicinity of Guangzhou is determined to be a major source area influencing regional concentrations of PM2.5, with levels observed to increase by 18{\textendash}34μgm-3 (accounting for 46{\textendash}56\% of resulting particulate levels) at sites immediately downwind of Guangzhou. The area near Guangzhou is also observed to heavily impact downwind concentrations of lead. Potassium levels, related to biomass burning, appear to be controlled by sources in the northern part of the Pearl River Delta, near rural Conghua and urban Guangzhou. Guangzhou appears to contribute 5{\textendash}6μgm-3 of sulfate to downwind locations. Guangzhou also stands out as a significant regional source of organic mass (OM), adding 8.5{\textendash}14.5μgm-3 to downwind concentrations. Elemental carbon is observed to be strongly influenced by local sources, with highest levels found in urban regions. In addition, it appears that sources outside of the Pearl River Delta contribute a significant fraction of overall fine particulate matter in Hong Kong and Guangdong province. This is evident in the relatively high PM2.5 concentrations observed at the background sites of 18μgm-3 (Tap Mun, southerly flow conditions) and 27μgm-3 (Conghua, northerly flow conditions).},
	keywords = {Transport},
	issn = {1352-2310},
	doi = {http://dx.doi.org/10.1016/j.atmosenv.2006.02.032},
	url = {http://www.sciencedirect.com/science/article/pii/S1352231006002391},
	author = {G.S.W.* Hagler and M.H. Bergin and L.G. Salmon and J.Z. Yu and E.C.H. Wan and M* Zheng and L.M. Zeng and C.S. Kiang and Zhang, Y. H. and A.K.H. Lau and J.J. Schauer}
}
