A seasonal study of polycyclic aromatic hydrocarbons (PAHs) in fine and coarse atmospheric particulate matter in five typical cities of Liaoning Province, China

Shaofei Kong(1), Xiao Ding(1), Bin Han(1), Zhipeng Bai(1), Li Chen(1), Jianwu Shi(1) , Hongliang Ji(1)

(1) State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, Nankai University

     Abstract Number: 431
     Last modified: November 28, 2009

Abstract
Fourteen priority polycyclic aromatic hydrocarbons (PAHs) in PM$_(2.5) and PM$_(2.5-10) samples collected in five cities (Shenyang, Anshan, Jinzhou, Fushun and Dalian), Liaoning Province, China in 2004 and 2005 were analyzed using a HPLC equipped with fluorescence and UV detectors to determine the composition, temporal and spatial distribution and sources. Total ten sites covering six different functional zones were selected. The total PAHs concentrations in PM$_(2.5) and PM$_(2.5-10) were in the range of 75.32–1900.89 ng m-3 and 16.74–303.24 ng m-3, respectively. In the fine fraction, the main PAHs compounds were Flu (23%), Pyr (21%), Ana (8.3%), Chr (7.9%) and BaA (7.4%); in the coarse fraction the dominant compounds were Flu (19.8%), Phe (19.0%), Pyr (16.7%), Ana (7.4%) and Chr (6.0 %) , indicating that coal combustion sources was one of the main sources for both the fraction. Moreover, Results showed that 90% of the PAHs were in the fine fraction. Higher total PAHs concentrations were found in summer than in winter. The fine fraction had a winter to summer ratio that varied from 6.5 to 125.8 and the coarse fraction had a ratio that ranged from 1.7 to 37.6. The concentrations of total PAHs were most abundant at residential/commercial sites and were fewest at an industrial site for both fine and coarse fraction. The urban background sites discussed in this study showed unexpected higher PAHs concentrations than that at the industrial site for PM$_(2.5) and higher PAHs concentrations than that at the residential sites as well as the industrial site for PM$_(2.5-10), respectively. The total BaPeq concentrations were found to be 20.66ng m-3, 88.42 ng m-3, 50.18 ng m-3, 7.80 ng m-3, 66.97 ng m-3 and 18.25 ng m-3 at RA, RCA, CA, IA, ICA and UBS, respectively. The highest total BaPeq concentrations in residential/commercial areas were an alarming signal for pollution risks. Similarities of PAHs profiles between two sampling sites within each city and between fine and coarse fraction were also compared by the coefficient of divergence revealing that the two sites in each city had comparable PAHs species concentrations and significant difference existed between fine and coarse fraction. Results obtained from PCA associated with diagnostic ratios and cluster analysis revealed that coal combustion and vehicle emissions were the major sources for both PM$_(2.5) and PM$_(2.5-10) associated PAHs in Liaoning Province. Other sources like natural gas buring and wood combustion were identified as common sources in these five cities.