Liaoning Province is the political and economic center of northeast China, and is the main region of heavy chemical industries in China. So the consumption of fossil fuels is remarkably increasing and combustion particulates containing polycyclic aromatic hydrocarbons (PAHs) and nitropolycyclic aromatic hydrocarbons (NPAHs) are emitted into the atmosphere with the exhaust gas. In recent years, in addition to domestic heating exhaust, industrial and automobile exhausts have caused much air pollution in Liaoning Province.
In this study, airborne particulates were collected in nine different particulate size fractions by using Andersen low-volume air samplers in Shenyang, Fushun and Tieling, Liaoning Province, during July 2001 - December 2003. Nine PAHs and ten NPAHs in the extracts from the particulates were analyzed by HPLC with fluorescence detection and chemiluminescence detection, respectively. The mean concentrations of the sums of the nine PAHs and ten NPAHs were highest in Fushun, which is an industrial city, and lowest in Shenyang, which is a commercial city, although the consumption of petroleum and coal were largest in Shenyang. The nine particulate fractions were mixed into three groups: › 7 μm, 2.1 ∼ 7 μm and ‹ 2.1 μm. In each city, more than 55% of the total PAHs and total NPAHs were found in the fine particulate fraction (‹ 2.1μm). All PAHs and NPAHs were clearly higher in winter than in summer. Our study also showed that the major contributors of atmospheric PAHs and NPAHs were coal combustion systems both in summer and winter in Fushun and Tieling. In Shenyang, atmospheric PAHs and NPAHs also seemed to be affected by coal combustion systems in winter, while gasoline-engine vehicles seemed to be a major contributor in summer.
