Fate of PAH

Park, K.S., Sims, R.C., Dupont, R.R., Doucette, W.J., Matthews, J.E. (1990) Fate of PAH compounds in two soil types Influence of volatilization, abiotic loss and biological activity. Environ. Toxicol. Chem. 9, 187-195. 

Sims, R.C.C. (1990) Fate of PAH compounds in soil loss mechanisms. Environ. Toxicol. Chem. 9, 187-. 

If sorption and partitioning mechanisms dominate the fate of PAHs in soils, then the PAHs remaining in SOM should be primarily parent compounds which are sorbed to organic surfaces. Slow rates of desorption become the primary limitation for biodegradation however, the presence of adapted PAH-minerali-zing communities in contaminated soils suggests that PAH desorption occurs at sufficient rates over time to establish and maintain adapted microbial communities [36,264,356]. PAH biodegradation appears to proceed, albeit at much slower rates than predicted or desired [264,278,279]. 

A particularly interesting group of compounds in combustion effluents are those with a vinylic bridge such as acenaphthylene (peak 4) and cyclopenteno[cd]pyrene (peak 32). Peak 23, although not labeled, has been positively identified as acephenanthrylene, a compound which also has a vinylic bridge. We emphasize this structural feature because of its chemical reactivity (compared to the fully aromatic portions of the PAH). We shall see later that this reactivity is important when considering the fate of PAH in the atmosphere. 

Kim, S.-K., 2004. Integrated Assessment of Multimedia Fates of PAHs and PCBs in Seoul Metropolitan Area, Korea. PhD dissertation, Seoul National University, Seoul, South Korea. 

J.S. Latimer and J. Zheng, The Sources, Transport and Fate of PAHs in the Marine Environment, PAHs An Ecotoxicological Perspective, Ed., P.E.T. Douben, John Wiley and Sons, Chichester, UK, 2003, p.9. 

Brenner, R. C., Magar, V. S., Ickes, J. A. et al. (2002). Characterization and fate of PAH-contaminated sediments at the Wyckoff/Eagle Harbor superfund site. Environmental Science and Technology, 36, 2605-13. 

The importance of studying the fate of PAHs in the environment can not be understated. PAHs are a ubiquitous, diverse group of organic compounds containing one or more fused aromatic rings. PAHs are found in air, water and soil samples due to contamination from combustion of hydrocarbons and from petroleum spills. But the fate of PAHs in the environment is hard to follow as a result of detection and... 

PAHs are spectroscopically active in the region where interference is more likely. These difficulties warrant the investigation of molecules that may serve as model compounds or analogues for studying biological systems and the fate of PAHs in biological systems. These needs led us to the investigation of aryl dyes. 

In the process of developing this analytical approach to studying the environmental fate of PAHs using red and NIR absorbing aryl dyes as analogues, we... 

Very little or no separation is required during detemiination of these aryl dyes in the media. Although the media exhibit a broad absorption peak severely interfering with the underivatized aryl compounds, very little interference is observed in the region where the chromophore absorbs, indicating the utility of using these aryl dyes as analogues to study the environmental fate of PAHs. 

Generally, oxidation with singlet oxygen and peroxy radicals are the two important oxidative processes for environmental pollutants in water. The rate constants for reactions of PAHs with singlet oxygen and peroxy radicals (Mabey et al. 1981) and the typical concentrations of the two oxidants in environmental waters (Mill and Mabey 1985) suggest that these reactions may not be important in controlling the overall fate of PAHs in water. 

The distribution and fate of PAHs in the atmosphere has been the subject of numerous studies covering a wide range of spatio-temporal scales and relevant sources (references in Finlayson-Pitts and Pitts 2000 Prevedouros et al. 2005 Tsapakis and Stephanou 2005 Lammel et al. 2009a Balasubramanian and He 2010). Most studies focused on occurrence of the parent PAHs, while nitro-PAHs gained interest in the chemistry of nitrogen oxides rich atmospheres (Finlayson-Pitts and Pitts 2000) and alkylated and partly oxygenated PAHs had significantly less been addressed so far (e.g. Albinet et al. 2008). 

Very little consideration has been given until now to the fate of PAH in the air. The nature and concentration of their transformation derivatives is practically unknown. Oxidation derivatives of PAH are a complex mixture of different compounds and probably generate toxification as well as detoxification processes. PAH emission levels, if regulated in the future, should be assessed in terms of possible hazardous conversion products. 

In estimating the biological properties of POM, two fields are nearly completely neglected and need emphasis i.e., the biological fate of PAH adsorbed on inhaled airborne particulates, and the fate of PAH-POM in the chemically and photochemically reactive atmospheric environment. 

The Octanol-water partition constant (Kow) is the ratio of the eoncentration of a substance in octanol to that in water at equilibrium at a speeified temperature (Asante-Duah 2002), (Kow) is used to predict the fate of PAHs either in the environment or in biological tissues. (Kow) increases with increasing benzene rings, from LMW PAHs to HMW PAHs. The (Kow) is used to determine the phase which the PAH shall partition to, this ability is very useful in human exposure analysis to PAHs (Asante-Duah 2002). Measurements of (Kow) of individual PAHs correlate perfeetly with measurements of solubility and hydrophobicity, with increasing hydrophobieity is low solubility and an increasing Octanol-Water partition coefficient. 

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