A seasonal study of polycyclic aromatic hydrocarbons in PM2.5 and PM2.5-10 in five typical cities of Liaoning Province, China.

Abstract Fourteen 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 by using a HPLC equipped with fluorescence and UV detectors. Results showed 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. 90% of the total PAHs were in PM 2.5 . PAHs in PM 2.5 had a winter to summer ratio varying from 6.5 to 125.8 while PAHs in PM 2.5–10 had a ratio ranging from 1.7 to 37.6. Total PAHs concentrations were most abundant at residential/commercial sites and were fewest at an industrial site for both PM 2.5 and PM 2.5–10 . Urban background sites showed unexpected higher PAHs concentrations. Total BaP equivalent concentration (BaPeq) for PM 2.5 ranged from 7.80 to 88.42 ng m −3 in different function zones. Similarities of PAHs profiles between sampling sites and between fine and coarse fractions were compared by coefficient of divergence which indicated that remarkable differences in PAHs compositions existed. Principal component analysis (PCA) associated with diagnostic ratios revealed coal combustion and vehicle emission were the major sources for PM 2.5 and PM 2.5–10 associated PAHs.