Polychlorinated PCDF

Dioxin and Furan Emissions. The emissions of polychlorinated dibenzo-/)-dioxins (PCDD) and polychlorinated dibenzo-furans (PCDF) from incinerators (4) are of interest to the pubHc, scientists, and engineers. The U.S. EPA classifies 2,3,7,8-tetrachlorodibenzo-/)-dioxin (2,3,7,8-TCDD) as the most potent carcinogenic compound it has evaluated. It is also Hsted as the agency s most potent reproductive toxin (4). 

Chlorobenzenes are stable compounds and decompose slowly only under excess heating at high temperatures to release some HCl gas and traces of phosgene. It is possible, under certain limited conditions of incomplete combustion or pyrolysis, to form polychlorinated dibenzo-/)-dioxins (PCDDs) and dibenzofurans (PCDFs) from chlorobenzenes (Cm OROCARBONS and cm OROHYDROCARBONS, toxic aromatics). 

In general, capillary gas chromatography provides enough resolution for most determinations in environmental analysis. Multidimensional gas chromatography has been applied to environmental analysis mainly to solve separation problems for complex groups of compounds. Important applications of GC-GC can therefore be found in the analysis of organic micropollutants, where compounds such as polychlorinated dibenzodioxins (PCDDs) (10), polychlorinated dibenzofurans (PCDFs) (10) and polychlorinated biphenyls (PCBs) (11-15), on account of their similar properties, present serious separation problems. MDGC has also been used to analyse other pollutants in environmental samples (10, 16, 17). 

PCDFs are similar in many respects to PCDDs but have been less well studied, and will be mentioned only briefly here. Their chemical structure is shown in Figure 7.1. Like PCDDs, they can be formed by the interaction of chlorophenols, and are found in commercial preparations of chlorinated phenols and in products derived from phenols (e.g., 2,4,5-T and related phenoxyalkanoic herbicides). They are also present in commercial polychlorinated biphenyl (PCB) mixtures, and can be formed... 

Coplanar PCBs, PCDDs, and PCDFs express Ah-receptor-mediated toxicity (Chapter 6, Section 6.2.4). Binding to the receptor leads to induction of cytochrome P4501 and a number of associated toxic effects. Again, toxic effects are related to the extent of binding to this receptor and appear to be additive, even with complex mixtures of planar polychlorinated compounds. Induction of P4501A1/2 has been widely used as the basis of a biomarker assay. Residue data can be used to estimate TEQs for dioxin (see Chapter 7, Section 7.2.4). 

Gotz R, P Friesel, K Roch, O Papke, M Ball, M, A Lis (1993) Polychlorinated-/ -dioxins PCDDs, dibenzofu-rans PCDFs, and other chlorinated compounds in the River Elbe results on bottom sediments and fresh sediments collected in sedimentation chambers. Chemosphere 27 105-111. 

Broman D, Naf C, Rolfif C, Zebuhr Y, Fry B, Hobbie J. 1992. Using ratios of stable nitrogen isotopes to estimate bioaccumulation and flux of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) in two food chains from the northern Baltic. Environ Toxicol Chem 11 331-345. 

CRMs for Contaminants in Environmental Matrices For nearly two decades NIST has been involved in the development of SRMs for the determination of organic contaminants such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and chlorinated pesticides in natural environmental matrices such as fossil fuels (Hertz et al.1980 Kline et al. 1985), air and diesel particulate material (May and Wise 1984 Wise et al. 2000), coal tar (Wise et al. 1988a), sediment (Schantz et al. 1990, 1995a Wise et al. 1995), mussel tissue (Wise et al. 1991 Schantz et al. 1997a), fish oil, and whale blubber (Schantz et al. 1995b). Several papers have reviewed and summarized the development of these environmental matrix SRMs (Wise et al. 1988b Wise 1993 Wise and Schantz 1997 Wise et al. 2000). Seventeen natural matrix SRMs for the determination of organic contaminants are currently available from NIST with certified and reference concentrations primarily for PAHs, PCBs, chlorinated pesticides, polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofiirans (PCDFs) see Table 3.11. 

Long, G., J. McKinney, and L. Pedersen. 1987. Polychlorinated Dibenzofuran (PCDF) Binding to the Ah Receptor(s) and Associated Enzyme Induction. Theoretical Model based on Molecular Parameters. Quant. Struct.-Act. Relat. 6, 1. 

Mader, B.T., Pankow, J.F. (2003) Vapor pressures of the polychlorinated dibenzodioxins (PCDDs) and the polychlorinated dibenzofurans (PCDFs). Atmos. Environ. 37, 3103-3114. 

C. Rappe and R. Lindahl, "Formation of Polychlorinated Dibenzofurans (PCDFs) and Polychlorinated Dibenzo-p-Dioxins (PCDDs) from the Pyrolysis of Polychlorinated Diphenyl Ethers,"Chemosphere, 2, 351 (1980). 

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. 

Loonen, H., J.R. Parsons, and H.A.J. Govers. 1994a. Effect of sediment on the bioaccumulation of a complex mixture of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) by fish. Chemosphere 28 1433-1446. 

Neubert, N., T. Wiesmuller, K. Abraham, R. Krowke, and H. Hagenmaier. 1990. Persistence of various polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs and PCDFs) in hepatic and adipose tissue of marmoset monkeys. Arch. Toxicol. 64 431-442. 

Van den Berg, M., B.L.H.J. Craane, T. Sinnige, S. Van Mourik, S. Dirksen, T. Boudewijn, M. Van der Gaag, I.J. Lutke-Schipholt, B. Spenkelink, and A. Brouwer. 1994. Biochemical and toxic effects of polychlorinated biphenyls (PCBs), dihcnzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) in the cormorant (.Phalacrocorax carbo) after in ovo exposure. Environ, Toxicol. Chem. 13 803-816. 

Macdonald, C.R., R.J. Norstrom, and R. Turle. 1992. Application of pattern recognition techniques to assessment of biomagnification and sources of polychlorinate multicomponent pollutants, such as PCBs, PCDDs, and PCDFs. Chemosphere 25 129-134. 

Safe, S. 1990. Polychlorinated biphenyls (PCBs), dibcnzo-p-dioxins PCDDs), dibenzofurans (PCDFs), and related compounds environmental and mechanistic considerations which support the development of toxic equivalency factors (TEFs). Crit. Rev. Toxicol. 21 51-88. 

Because of very high toxicity, ability of delayed action and high stability in the environment, polychlorinated dibenzodioxins (PCDD), dibenzofurans (PCDF) and biphenyls (PCB) are particularly hazardous for people s health if misused for committing acts of terrorism, or under the circumstances of violating the rules of toxic wastes safe storage. 

Dioxins is a generalized name of the large group of polychlorinated dibenzoparadioxins (PCDD) and polychlorinated dibenzofurans (PCDF). 

Investigations have shown that plants on thermal treatment of solid domestic waste represent the source of polychlorinated dibenzodioxins and biphenyls. In this connection, it is necessary to conduct further investigations of their emission and determination of all the range of PCDD, PCDF and PCB... 

Figure 19. General formulas of polychlorinated dibenzo-pdioxins, PCDDs (left) and polychlorinated dibenzofurans, PCDFs (right).

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... 

The presence of chlorine and chlorinated compounds is also the source of dioxins and furans during paper making, and these compounds have been detected in sediments in the vicinity of a pulp and paper mill [53] and in effluents, along with polychlorinated dibenzothiophenes [54]. A recent study found high concentrations of PCDD and PCDF along with PCP in nestling tissue (Tachycineta bicolor) collected downstream of paper pulp mills, suggesting that the primary source of contaminants was the use of PCP for timber preservation [55]. In addition, it has been shown that dioxins bioaccumulate in fish downstream of pulp and paper mills [56]. The levels of chlorinated compounds of different families are shown in Fig. 3. 

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