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Air pollution VII | Air pollution 7 | Air pollution seven
1999
Brebbia, C. A. | Jacobson, M. A. | Power, H.
"This book contains over 100 contributions from the Seventh International Air Pollution Conference, held in July 1999. Bringing together recent results from state-of-the-art research projects world-wide, the goal of this meeting was to increase public awareness of air pollution issues and lay the groundwork for further investigations."--BOOK JACKET.
Mostrar más [+] Menos [-]Sources and control of air pollution | Air pollution
1999
Heinsohn, Robert Jennings | Kabel, Robert Lynn
"Students and practitioners alike will find Sources and Control of Air Pollution by Heinsohn and Kabel to be a comprehensive treatment of possible contamination of the atmosphere, the physical and social environment in which it occurs, and the resultant impacts. The cultural, aesthetic, biological, physiological, ecological, legal and economic contexts of air pollution are addressed in depth as are the scientific and engineering principles used to mitigate it."--Jacket.
Mostrar más [+] Menos [-]Photo-Induced OH reactions of naphthalene and its oxidation products on SiO2
1999
Brussol, Claire | Duane, Matthew | Carlier, Patrick | Kotzias, Dimitrios
The photo-induced degradation of naphthalene, 1,4-naphthoquinone, 1-naphthol and 1-NO₂ naphthalene, adsorbed on silica gel, and with the addition of nitrogenous air pollutants e.g. NO₂ (as KNO₂) was investigated. Results indicate that compounds adsorbed onto a solid carrier are degraded when irradiated with UV light (λ > 290 nm) in the presence of nitrites. The key species initiating the naphthalene degradation is the OH-radical which is generated through the photolysis of NO₂. Reaction products identified were 2-formyl-cinnamaldehyde, 1,4-naphthoquinone, nitronaphthol, o-phthaldialdehyde, phthalide and nitronaphthalene. A mass balance between 40–50% was achieved. Under the same irradiation conditions, 1-NO₂ naphthalene is mainly degraded by direct photolysis while degradation of 1-naphthol and 1,4-naphthoquinone proceeds via the reaction with OH-radicals. Identified products were hydroxy-nitro-nitroso- and quinones compounds.
Mostrar más [+] Menos [-]The variation of street air levels of PAH and other mutagenic PAC in relation to regulations of traffic emissions and the impact of atmospheric processes
1999
Nielsen, Torben | Feilberg, Anders | Binderup, Mona-Lise
The occurrence of particle associated PAH and other mutagenic PAC was determined in 1996 in the street air of Copenhagen. In addition, particle extracts were tested for mutagenicity. The measurements were compared with previous measurements in 1992/1993. The levels had decreased in this period. The decrease was caused by an implementation of light diesel fuels for buses and the exchange of older petrol-driven passenger cars with catalystequipped new ones. About 65% of the reduction was caused by the application of the light diesel fuels. Under special conditions, chemical processes in the atmosphere produced many more mutagens than the direct emissions. The concentrations of S-PAC and N-PAC were 10 times lower than those of PAH, while the levels of oxy-PAH were in the same order of magnitude as those of PAH. Benzanthrone, an oxy-PAH, is proposed to be formed in the atmosphere in addition to direct emissions. Benzo(a)pyrene, often applied as an air quality criteria indicator, was photochemically degraded in the atmosphere. A strong increase in the mutagenic activities was observed to coincide with a depletion of benzo(a)pyrene.
Mostrar más [+] Menos [-]Measurements of selected PCBs in open urban ambient air of Madrid (Spain) : First results
1999
García-Alonso, Susana | Pérez-Pastor, Rosa María | Sevillano-Castaño, María Luisa
The focus of this study was to characterize the concentration levels of selected PCBs and compare them to compiled data in order to contribute to the international database. The sampling site is located in the outskirts of Madrid and can be considered an open urban area. 32 samples of air were taken from February 1998 to June 1998 by using a high volume air sampler. Glass fiber filters and polyurethane foam (PUF) were used to collect the paniculate and gas phase material, respectively.PUF plugs were Soxhlet extracted and filters were ultrasonically extracted by using pesticide-grade hexane and dichloromethane, respectively. The cleanup procedure was carried out on a florisil column with hexane and hexane/dichloromethane as elution solvents.GC/MS in a selected ion monitoring mode was used for quantification and 29 selected PCBs congeners were analyzed.
Mostrar más [+] Menos [-]An assessment of the effects of human-caused air pollution on resources within the interior Columbia River basin
1999
Schoettle, Anna