Polychlorinated dibenzo-p-furans

NP NPEC OC OP OPEC PCB PCDBT PCDD PCDF PCP PFB RA TCA TCDD TCF TCMTB TOC VSC VOC Nonylphenol Nonylphenol ethoxycarboxylate Organo chlorine Octylphenol Octylphenol ethoxycarboxylate Polychloroinated biphenyls Polychlorinated dibenzothiophene Polychlorin ated dib enzo-p - dioxins Polychlorinated dibenzo-p-furans Pentachlorophenol Pentafluorobenzyl Resin acids 2,4,6-Trichloroanisole Tetrachloro dibenzo dioxin Totally chlorine- free 2-(Thiocyanomethylthio)-benzothiazole Total organic carbon Volatile sulphur compounds Volatile organic compounds... 

Key words Polychlorinated dibenzo-p-dioxins (PCDDs) polychlorinated dibenzo-p-furans (PCDFs) sewage sludge household sewage and municipal wastewater treatment plant (MWTP)... 

Dioxin is the widely used term that is used by the public to describe the polychlorinated dibenzo-p-furans (PCDFs) and polychlorinated dibenzo-p-dioxins... 

Leung AOW, Luksemburg WJ, Wong AS, Wong MH (2007) Spatial distribution of polybrominated diphenyl ethers and polychlorinated dibenzo-p-dioxins and dibenzo furans in soil and combusted residue at Guiyu, an electronic waste recycling site in southeast China. Environ Sci Technol 41 2730-2737... 

In addition, the concern about e-waste not only focuses on its vast quantity generated daily, but also more on the need to handle the toxic chemicals embedded in it. It is well known that e-waste contains lead, beryllium, mercury, cadmium (Cd), and brominated flame retardants (BFRs) among other chemical materials [3]. Furthermore, highly toxic chemicals such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polybrominated dibenzo-p-dioxins and dibenzo-furans (PBDD/Fs) can be formed during the recycling process [4]. 

Bignert, A., M. Olsson, P.A. Bergqvist, S. Bergek, C. Rappe, C. de Wit, and B. Jansson. 1989. Polychlorinated dibenzo-p-dioxins (PCDD) and dibenzo-furans (PCDF) in seal blubber. Chemosphere 19 551-556. 

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. 

Polychlorinated Dibenzo-(p)-Dioxins and Dibenzo-Furans. Another group of compounds that we need to specifically address are the polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzo-furans (PCDFs) (Fig. 2.15). The PCDDs and PCDFs are not intentionally produced but are released into the environment from various combustion processes and as a result of their occurrence as unwanted byproducts in various chlorinated chemical formulations (e.g., chlorinated phenols, chlorinated phenoxy herbicides see Alcock and Jones, 1996). Because some of the PCDD and PCDF congeners are very toxic (e.g., 2,3,7,8-tetrachloro dibenzo-p-dioxin, see margin), there have been and still are considerable efforts to assess their sources, distribution, and fate in the environment. Similarly to the PCBs or DDT (see above), the PCDDs and PCDFs are highly hydrophobic and very persistent in the environment. It is therefore not surprising that they have also been detected everywhere on earth (Brzuzy and Hites, 1996 Lohmann and Jones, 1998 Vallack et al., 1998). Finally, we should note that polybrominated diphenylethers (PBDEs, see margin) that, like the PBBs (see above), are used as flame retardants, are of increasing environmental concern (de Boer et al., 2000). 

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],... 

As discussed in the earlier survey (1), a biogenic source of polychlorinated dibenzo-p-dioxins and dibenzofurans is peroxidase-catalyzed transformation of chlorophenols as first reported by Oberg and Rappe (2041-2044). More recent studies confirm these observations (2045-2048). In addition to lactoperoxidase and horseradish peroxidase, human leukocyte myeloperoxidase catalyzes in vitro formation of dioxins and dibenzofurans from chlorophenols (2046, 2047). Formation rates are in the pmol/mol range (Scheme 3.6) demonstrating that a human biosynthesis of dioxins and furans is not only possible but also likely. These observations are reinforced by the reported in vivo (rats) conversion of the pre-dioxin nona-chloro-2-phenoxyphenol to octachlorodibenzo-p-dioxin (OCDD) (2049), and the production of hepta- and octachlorodibenzo-p-dioxin in the feces of cows fed pentachlorophenol-treated wood (Scheme 3.7) (2050, 2051). 

Wunderli S, Zennegg M, Dolezal IS, Gujer E, Moser U, Wolfensberger M, Hasler P, Noger D, Studer C, Karlaganis G (2000) Determination of Polychlorinated Dibenzo-p-dioxins and Dibenzo-furans in Solid Residues from Wood Combustion by HRGC/HRMS. Chemo-sphere 40 641... 

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. 

Zhang, Q.H., Jiang, G.B., 2005. Polychlorinated dibenzo-p-dioxins/furans and polychlorinated biphenyls in sediments and aquatic organisms from the Taihu Lake, China. Chemosphere 61, 314-322. 

Ueno, D., Watanabe, M., Subramanian, A., Tanaka, H., Fillmann, G., Lam, P.K., Zheng, G.J., Muchtar, M., Razak, H., Prudente, M., Chung, K.FL, Tanabe, S., 2005. Global pollution monitoring of polychlorinated dibenzo-p-dioxins (PCDDs), furans (PCDFs) and coplanar polychlorinated biphenyls (coplanar PCBs) using skipjack tuna as bioindicator. Environ. Pollut. 136, 303-313. 

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. 

Opperhuizen, A., Sijm, D.T.H.M. (1990) Bioaccumulation and biotransformation of polychlorinated dibenzo-p-dioxins and dibenzo-furans in fish. Environ. Toxicol. Cltem. 9, 175-186. 

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. 

Wild SR, Harrad SJ, Jones KC. 1993. The influence of sewage sludge applications to agricultural land on human exposure to polychlorinated dibenzo-p-dioxins (PCDDs) and -furans (PCDFs). Environ Pollution 357-369. 

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... 

These chemicals have received intense international attention in recent years because of their ubiquity, persistence, high bioaccumulation potential and harmful biological effects. Under the Stockholm Convention on POPs (see Chapter 1), 12 chlorinated chemical substances have been banned or severely restricted. These include dioxins and furans (polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans, PCDD/Fs),... 

Loganathan, B.G., Kumar, S., Iseki, N., Masunaga, N. (2001). Polychlorinated dibenzo-p-dioxin/furan and dioxin-like PCB concentrations in sediments and mussel tissues from Kentucky Lake, USA. Organohalogen Compounds 51 158-61. 

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. 

POPs are widespread in human food productsJ7 An indication of the pervasiveness of POPs is seen from a worldwide study of butter contamination with PCBs, polychlorinated dibenzo-p-dioxins (PCDDs), dibenzo-furans (PCDFs), hexachlorobenzene, and DDT and its metabolites. These POPs were found to be present in varying degrees in the butter of 37 different nations. ... 

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