抄録
Organic aerosols were studied at molecular level in 14 coastal and inland mega-cities in China during 2003 winter and summer. They are characterized by the abundant presence of n-alkanes (annul average, 340 ng m-3), fatty acids (769 ng m-3), sugars (412 ng m-3), and phthalates (387 ng m-3). In contrast, fatty alcohols, polyols/polyacids, lignin and resin products, sterols, polycyclic aromatic hydrocarbons (PAHs) and hopanes were detected as relatively minor components. n-Alkanes show a weak odd/even carbon predominance (CPI = 1.1) and PAHs do the predominance of benzo(b)fluoranthene, suggesting a serious contribution from fossil fuel (mainly coal) combustion. Their concentrations (except for phthalates and polyols/polyacids) were 2-15 times higher in winter than summer due to a significant usage of coal burning and an enhanced atmospheric inversion layers. Phthalates were found to be more abundant in summer than winter, probably due to enhanced vaporization from plastics followed by adsorptive deposition on the pre-existing particles. Concentrations of total quantified compounds are extremely high (∼10 μg m-3) in the mid-west (Chongqing and Xi'an), where active industrialization/urbanization is going on. This study shows that concentrations of the compounds detected are 1-3 orders of magnitude higher than those reported from developed countries.
