Characteristies Of Distribution And Sources Of Organic Compounds In The Winter Atmospherical Particles In Lanzhou

Total suspended particle (TSP) is one of the most important pollutions in urban air. It has adverse effects on respiratory system and cardiovascular system, as well as eyes and naked skin. Organic compounds are important contents in TSP. They have carcinogenicity and mutagenicity and inheritable, immune or pulmonary toxicity. In Organic compounds, n-alkanes are important trace markers for sources of particulate matter and polycyclic aromatic hydrocarbons (PAHs) are the most hazard materials. It has been confirmed that several PAHs have carcinogenicity of different degrees. The concentration of PAHs in urban TSP is relative high, PAHs are ubiquitous contaminants of great environmental concern.Lanzhou is an industrial city, industrial pollution is serious. Meteorological conditions and special geographic environment of Lanzhou make winter air pollution worse. Lanzhou's pollution had a "coal-dust" profile previously. But now, industrial consumed petroleum is become more and more. There have been few studies on organic compounds in the winter atmospherical particles in Lanzhou recently. From December 2004 to March 2005, 16 TSP samples had been collected, and analysed by gas chromatography/mass spectrometry (GC/MS).The concentration of individual n-alkanes ranging from C₁₇ to C₃₃, the C_max are C₂₃, C₂₉, respectively. Emissions from vehicles and coal burning are the main sources of organic compounds in TSP.26 PAHs had been identified in all samples and methyl-PAHs are ubiquitous. On average, the sum of fluoranthene, pyrene, chrysene and benzofluoranthene emission rates amounted most of total PAHs emissions, which contributed to burning of fossil fuel rather than evaporation. Fluoranthene to pyrene concentration ratios were found ranging from 1.1 to 1.8 and indeno(l,2,3-cd)pyrene to benzo(ghi)perylene ratios ranging from 0.08 to 1.11.Fossil fuel (Oil and coal) sources are responsible for the presence of organic compounds in the atmosphere of Lanzhou, while a fraction has comes from modern biologic source.