| Atmospheric dust is an important component of the aerosol,it produces a series of important effect on the environment, ecosystems and material exchange.Dust is easy settlement, It lead to part of the organic pollutants in the atmosphere deposition and settlement in near source, and through surface water such as rainwater enter the City waters or the dust directly access to waters. So city and the surrounding areas of water and sediment are polluted, and eventually enter the body through the food chain.Polycyclic aromatic hydrocarbons (PAHs) are a kind of POPS, widespread in the atmosphere,contributing more than 1/3 of the total carcinogenic chemicals.It comes from oil-leak,traffic emissions,environmental tobacco smoke,fuel-burning,cooking oil– fumes and so on.PAHs pollution in air emphasized threat on the whole human. Researching PAHs in the atmosphere and understanding of occurrence, sources and fates for PAHs in environment is the basis of controlling POPS pollution efficiently, thus reducing personal intake andprotecting human health.The samples of dust were collected in 2006～2007 at Yuzhong, Jingbei, Nanan, Shangbingba, Yubei, Dadukou, Jiulongpo, Banan, Beibei ,9sampling sites of Chongqing urban and Jinyunshan site for compared, and analyzed for the temporal and spatial distribution of dust.And the samples of dust were collected again in 2007 at major functional areas such as tourism, transportation, business, industrial districts and school residential areas, analyzed for the distribution of 15 kinds of PAHs in dust. The main conclusion is as follow:①Chongqing City dust pollution remains serious. The monthly volume of dust was 7.09 ~ 13.06 t / (30d·km~2) in Chongqing City in 2007, and the average of 9.59 t / (30d·km~2), lower the 3.27 t / (30d·km~2) than 2006, but the monthly volume of dust was still significantly higher than the regional environmental dust evaluation criteria, it was still more 40% than standard-value, so the durst-pollution of Chongqing city was also heavy.②General in Chongqing City in January, April, September dust level is higher than in neighboring, February and July are the smallest amount in dust. The highest dust in the main city district was Dadukou,13.06 t / (30d·km~2), the lowest Yubei District, 6.19 t / (30d·km~2).Dust-quantity descending order was as follow: Integrated industrial areas>School residential areas>commercial areas>transport populated areas>tourist areas.③Using of the high performance liquid chromatography with fluorescence detection determinate PAHs in the dustfall, REVERSE PHASE C18 column used to acetonitrile water as a mobile phase of the establishment of multi-gradient elution procedures and fluorescence wavelength programming through optimized PAHs in the best of the compounds and fluorescence excitation wavelength emission wavelength. Access to the 15 kinds of polycyclic aromatic hydrocarbons compounds ideal separation efficiency, so as to establish a high-performance liquid chromatography assay programming dustfall of Polycyclic Aromatic Hydrocarbons in the analysis method.④The total compounds of 15 kinds of polycyclic aromatic hydrocarbons in atmospheric dust in Chongqing Municipality five sampling points are 6.48-73.48μg / g, with an average concentration for the spring 23.83μg / g, summer 12.92μg / g, autumn 13.95μg / g, winter 25.36μg / g, respectively.⑤There is an obvious seasonal characteristics of Polycyclic aromatic hydrocarbons in dust in the area of Chongqing distribution. The average concentration of the 15 kinds of polycyclic aromatic hydrocarbons compounds of detection raising order was: summer |
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