Combustion anthropogenic

Polycyclic aromatic hydrocarbons (PAHs) polycyclic aromatic hydrocarbons are a suite of compounds comprised of two or more condensed aromatic rings. They are found in many petroleum mixtures, and they are introduced to the enviromnent predominantly through natural and anthropogenic combustion processes. 

The key sources of CDD releases to air are from anthropogenic combustion processes and the production and use of chemicals contaminated with CDDs. Some evidence suggests that natural combustion processes (e.g., forest fires or volcanic activity) may also be sources of CDDs, but to a much smaller extent. Toxics Release Inventory (TRI) data are not available for CDDs since CDD releases are not required to be reported (EPA 1995g). 

Farrar, N.J., Smith, K.E.C., et al (2004b) Atmospheric emissions of polyhrominated diphenyl ethers and other persistent organic pollutants during a major anthropogenic combustion event. Environmental Science and Technology, 38(6) 1681-1685. 

PAHs to distinguish them from the petrogenic PAHs derived directly from uncombusted petroleum, coal, and their by-products. Natural sources such as forest fires could be important in less inhabited and remote watersheds, but anthropogenic combustion of fossil fuel (e.g., petroleum, coal) and wood is the dominant source of pyrogenic PAHs (Neff, 1979 Bjorseth and Ramdahl, 1983 Ballentine et al., 1996 O Malley et ai, 1997). 

Nitrogen oxide, formed by photofragmentation of N02 or chlorine nitrate (C10N02), hydroxyl radicals and some other reactive species are also responsible for stratospheric ozone depletion. These compounds may have both natural and anthropogenic (combustion, etc.) origin. Atmospheric chemistry also takes place in aerosol particles, cloud droplets1370 and ice crystals.1371,1372... 

Table VI summarizes aerosol mass concentrations and composition in different regions of the troposphere. It is interesting to note that average total fine particle mass (that associated with particles of diameter less than about 2 /im) in non-urban continental, i.e., regional, aerosols is only a factor of two lower than urban values. This reflects the relatively long residence time of particles (recall the estimate of a lifetime of fine particles by dry deposition of 10 days). Correspondingly, the average composition of non-urban continental and urban aerosols is roughly the same. The average mass concentration of remote aerosols is a factor of three lower than that of non-urban continental aerosols. The elemental carbon component, a direct indicator of anthropogenic combustion sources, drops to 0.3% in the remote aerosols, but sulfate is still a major compo-...

Can the PAH found in the remainder of the samples listed in Table III also be associated with anthropogenic combustion The total concentrations of PAH from the samples outside the Northeast are considerably lower the highest is 400 ppb for a Mono Lake sediment. These... 

Polycyclic aromatic hydrocarbons (PAHs) are a class of organic micropollutants containing two or more condensed rings. Apart from those cases associated with oil pollution, PAHs are produced mainly by anthropogenic combustion and are typically found in the environment as complex mixtures. However, not all components exhibited the same level of toxicity, and congener-specific determination has again become mandatory. 

Falconer RL, Bidleman TF, Gotham WE (1995) Preferential sorption of non- and mono-ortho-polychlorinated biphenyls to urban aerosols. Environ Sci Technol 29 1666-1673 Farrar NJ, Smith KEC, Lee RGM et al (2004) Atmospheric emissions of polybrominated diphenyl ethers and other persistent organic pollutants during a major anthropogenic combustion event. Environ Sci Technol 38 1681—1685 Finizio A, Mackay D, Bidleman T et al (1997) Octanol-air partition coefficient as a predictor of partitioning of semi-volatile organic chemicals to aerosols. Atmos Environ 31 2289-2296 Finlayson-Pitts BJ, Pitts JN Jr (1986) Atmospheric chemistry fundamentals and experimental techniques. Wiley, New York... 

Polycyclic aromatic compounds (PAH) are a complex group with compounds that can be indicative of petrogenic sources, anthropogenic combustion, forest fires, or biogenic transformation processes. Perylene has been suggested as a biogenic marker in particular from diatomaceous rich sediments (Gaskell et al, 1975 Killops and Killops, 1993). 

Polycyclic aromatic hydrocarbons (PAHs) occur widely in the environment and, even though they come from both natural (volcanic eruptions and forest and prairies fires) and anthropogenic (combustion of fossil fuels, waste incineration, coke and asphalt... 

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