Polychlorinated dibenzo-p-dioxins and furans

Incineration of domestic waste is also a contributor to environmental pollution. One more source of dioxins is pulp-and-paper industry. Comparatively new ways of forming polychlorinated dibenzo-p-dioxins and furans are high-temperature processes like copper melting in electric arc furnaces, and production of magnesium, nickel and, possibly, other metals of their chlorides. 

Formation of polychlorinated dibenzo(p) dioxins and furans (PCDD/PCDF) in waste combustion has received considerable attention, because dioxins even in very small concentrations are believed to be harmful to humans. Sources of PCDD/PCDF include the waste itself, gas-phase and heterogeneous reactions within the combustion zone, and catalyzed reactions in the low-temperature region downstream [352],... 

Ruokojarvi P, Ettala M, Rahkonen P, Tarhanen J, Ruuskanen J (1995) Polychlorinated Dibenzo-p-dioxins and -Furans (PCDDs and PCDFs) in Municipal Waste Landfill Fires. Chemosphere 30 1697... 

Group of isomers with the same carbon skeleton and number of chlorines, e.g., TeCDDs Rat hepatoma cell line Polychlorinated biphenyls Polychlorinated dibcnzo-p-dioxin Polychlorinated dibenzofuran Polychlorinated dibenzo-p-dioxin and -furan Tetrachlorodibenzo-p-dioxin (-furan) Pentachlorodibenzo-p-dioxin ( furan) Hexachlorodibenzo-p-dioxin (-furan) Heptachlorodibenzo-p-dioxin ( furan)... 

Oh, J.R., Hong, S.H., Shim, W. J., Kannan, N., 2005a. A survey of polychlorinated dibenzo-p-dioxins and furans in Korean seafood—A congener-specific approach. Mar. Pollut. Bull. 50, 1121-1127. 

Huwe, J.K., W.L. Shelver, L. Stanker, et al. 2001. On the isolation of polychlorinated dibenzo-p-dioxins and furans from serum samples using immunoaffinity chromatography prior to high-resolution gas chro-matography-mass spectrometry. J. Chromatogr. B 757 285-293. 

Friedrich C, Kleiboehmer W. 1997. Supercritical co2-assisted liquid extraction of polycyclic aromatic hydrocarbons and polychlorinated dibenzo-p-dioxins and -furans from solid matrices. Journal of Chromatography A 777(2) 289-294. 

Kjeller LO, Jones KC, Johnston AE, Rappe C (1991), Environ. Sci. Technol. 25 1619-1627.. .Increases in the polychlorinated dibenzo-p-dioxin and -furan content of soils and vegetation... 

Many of the toxic and biological effects induced by polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) and PCBs such as carcinogenesis, reproductive disturbances and immunotoxic effects are believed to be mediated via the hepatic cytosolic aryl hydrocarbon receptor (Ah receptor) [254,255]. Based on in vitro and in vivo studies, the toxicity of individual organochlorines have been determined relative to 2,3,7,8-tetrachlorodibenzo-p -dioxin (TCDD) and expressed as toxic equivalency factors (TEFs) [254, 256]. In addition to PCDD/F, structurally related PCBs and PCNs bind to the Ah receptor. After binding to the Ah-receptor, the receptor-ligand complex is transferred into the nucleus where it binds to specific DNA sequences and causes transcription of structural genes, which in turn causes synthesis of various cytochrome P4501A1-dependent enzymes such as ethoxyresorufin O-deethylase (EROD) and aryl hydrocarbon hydroxylase (AHH). TEFs for PCNs have been estimated from enzyme-induction assays of EROD and AHH [10, 257] and Luciferase assays in rat cells [12] cf. Table 4. 

Fig. 7.25 Chemical structures of the contrasting persistent organic pollutants (POPs), polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and furans (PCDDs/PCDFs), p,p -dichlorodiphenyl trichloroethane (DDT) and hexachlorocyclohexane (HCH). Symbols x and y indicate the possible number of chlorines attached to the ring structures.

Lenoir, D. Wehrmeier, A. Schram K.W., et al. Thermal formation of polychlorinated dibenzo-p-dioxins and -furans investigations on relevant pathways. Environ. Eng. Sci. 1998, 15, 37-47. 

In June 1997, an expert meeting was organized by the World Health Organization (WHO) to reach a consensus about TEFs for human and wildlife of polychlorinated dibenzo-p-dioxins and -furans (PCDD/Fs) and PCBs. " " Twenty-nine congeners of these compound classes were... 

Van Rhijn, J. A., Traag, W. A., van de Spreng, P. F., and Tuinstra, L. G. M. Th., Simultaneous determination of planar chlorobiphenyls and polychlorinated dibenzo-p-dioxins and -furans in Dutch milk using isotope dilution and gas chromatography-high-resolution mass spectrometry, J. Chromatogr., 630, 297-306, 1993. 

A large number of pubUcations have resulted from research on environmental appHcations of GC-MS. The compounds most commonly analyzed include alkanes, PAHs, pesticides, volatile organic compounds (VOCs) including off-flavor and water disinfection by-products (DBPs), PCBs, polychlorinated dibenzo-p-dioxins, and furans (PCDDs/Fs), as well as other ED chemicals such as phthalates and short ethoxy alkylphenol ethoxylate. GC-MS is also the technique of choice for the analysis of emerging contaminants, such as polybrominated diphenyl ethers (PBDEs) or polychlorinated alkanes, as well as for the analysis of some pharmaceuticals and organo-metallic compounds. 

MS has been the leading technique used in dioxin analysis. Until the 1990s, ultratrace determinations of polychlorinated dibenzo-p-dioxins and furans (PCDDs/Fs) were routinely performed using GC-HRMS, operating in the El mode (electron energy... 

The most studied organic compounds in the aerosol are the persistent organic compounds (POPs) as polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs), polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), polybrominated diphenyl ethers (PBDEs) and polycyclic aromatic hydrocarbons (PAHs). 

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