Dibenzo dioxin

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). 

As shown by several investigations [91], the bromine-rich polybromide phase by itself is hardly flammable and fireextinguishing properties have been reported occasionally. The formation of polybrominated dibenzo-dioxins (PBrDD) and furans (PBrDF) due to the plastic-containing housing of a zinc-flow battery cannot be totally neglected in the case of a fire, but their concentrations are far away from the tetrachloro dibenzodioxine (TCDD) toxic equivalents even in a worst-case scenario. 

Table I. Composition of Products during the Chlorination of Dibenzo- -dioxin...

Uniformly labeled 2,4-dichlorophenol- C (purchased from New England Nuclear Corp, Boston, Mass.) was used in the tracer preparation. This provided a label at all carbon positions in the dibenzo-dioxin structure. 2,7-Dichlorodibenzo-p-dioxin- C after initial cleanup by fractional sublimation, contained approximately 5% of an impurity, detected by thin layer chromatography (TLC) which gave mass peaks at 288, 290, 292, and 294 in the mass spectrometer, consistent with a trichloro-hydroxydiphenyl oxide. This is probably the initial condensation product of the Ullman reaction and is most likely 2-(2,4-dichlorophenoxy)-4-chlorophenol. It was removed easily by extractions with aqueous... 

Table I. GLC Characteristics of Dibenzo- -dioxin and its Chlorinated Derivatives...

Table I. Absorption Maxima of Chlorinated Dibenzo- >-dioxins...

Table III. Comparison of Measured ESR Parameters of Dibenzo- -dioxin in TFMS and Sulfuric Acids...

Figure 3. Clearance of activity from the body of rats given a single oral dose of 50 fig/kg (0.14 fxCi/kg) 2,3,7,8-tetrachloro-dibenzo- -dioxin. Each value represents the mean SE for three...

Baker 11, RA Hites (2000) Is combustion the major source of polychlorinated dibenzo-/ - dioxins and diben-zofurans to the environment A mass balance study. Environ Sci Technol 34 2879-2886. 

Brubaker WW, RA Hites (1997) Polychlorinated dibenzo-/)-dioxins and dibenzofurans gas-phase hydroxyl radical reactions and related atmospheric removal. Environ Sci Technol 31 1805-1810. 

Habe H, J-S Chung, J-H Lee, K Kasuga, T Yoshida, H Nojiri, T Omori (2001) Degradation of chlorinated dibenzofurans and dibenzo-/)-dioxins by two types of bacteria having angular dioxygenases with different features. Appl Environ Microbiol 67 3610-3617. 

Happe B, ED Eltis, H Poth, R Hedderich, KN Tunmis (1993) Characterization of 2,2, 3-trihydroxybiphenyl dioxygenase, an extradiol dioxygenase from the dibenzofuran- and dibenzo-/ -dioxin-degrading bacterium Sphingomonas sp. strain KWl. J Bacteriol 175 7313-7320. 

Wilkes H, RM Wittich, KN Timmis, P Fortnagel, W Francke (1996) Degradation of chlorinated dibenzofnrans and dibenzo-/ -dioxins by Sphingomonas sp. strain RWl. Appl Environ Microbiol 62 367-371. 

Evers EHG, HJC Klamer, RWPM Laane, HAJ Covers (1993) Polychlorinated dibenzo- -dioxin and dibenzo-furan residues in estuarine and coastal North Sea sediments Sources and distribution. Environ Toxicol Chem 12 1583-1598. 

Hewitt LM, JH Carey, KR Munkittrick, JL Parrott, KR Solomon, MR Servos (1998) Identification of chloro-nitro-trifluoromethyl-substituted dibenzo-/ -dioxins in lampricide formulations of 3-trifluoromethyl-4-nitrophenol assessment to induce mixed function oxidase activity. Environ Toxicol Chem 17 941-950. 

Takada S, M Nakamura, T Matsueda, R Kondo, K Sakai (1996) Degradation of polychlorinated dibenzo-/ -dioxins and polychlorinated dibenzofurans by the white rot fnngns Phanerochaete sordida YK-624. Appl Environ Microbiol 62 4323-4328. 

PCDDs/Fs Polychlorinated dibenzo-/ -dioxins/polychlorinated dibenzofurans... 

Hayton, A., D. Hollinger, C. Tashiro, and E. Reiner. 1990. Biological monitoring of chlorinated dibenzo-dioxins in the Rainy River using introduced mussels (Elliptio complanata). Chemosphere 20 1687-1693. 

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... 

More recently, however, investigations into the formation and occurrence of polychlorodibenzofurans suggest that this family of toxic compounds may commonly occur at comparable or greater levels than the dibenzo dioxins and could generally pose a greater hazard than polychlorodibenzo-p-dioxins. Polychlorodibenzofurans are often found as cocontaminants in and are readily produced from pyrolysis of polychlorobiphenyls [83, 99-102], Most important, the... 

GC-EI-MS permits the direct analysis of mixtures, e.g., to analyze synthetic byproducts an advantage that made GC-EI-MS benchtop instruments become widespread in modem synthetic laboratories. The GC-EI-MS combination is especially successful in monitoring environmental pollutants such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), polychlorinated dibenzo-dioxins (PCDDs), polychlorinated dibenzofuranes (PCDFs), or other volatile organic compounds (VOCs). 

Of additional concern is the thermal conversion of PCBs to polychlorinated dibenzofurans, especially when PCB—filled electrical transformers are involved (16). Further, PCB isomers with no chlorine atoms substituted in the ortho. ortho -biphenvl positions are particularly potent as inducers of aryl hydrocarbon hydroxylase activity. The potency of certain dibenzofurans and non-ortho, ortho chlorine substituted PCBs in inducing activity of these enzymes is similar to that of the highly toxic 2,3,7,8-tetrachloro-dibenzo- -dioxin (15. 17., 18). 

Rappe, C. Buser, H.-R. in "Topics in Environmental Health, Halogenated Biphenyls, Terphenyls, Naphthalenes, Dibenzo dioxins and Related Products, Kimbrough, R. D., Ed. Elsevier/North Holland Biomedical Press New York, 1980 Chap. 2. 

A The Analysis of Polychlorinated Dibenzo-/>-dioxins and Polychlorinated Dibenzofiirans by High Resolution GC/Low Resolution MS... 

Friesen, K.J., Sarna, L.P., and Webster, G.R.B. Aqueous solubility of polychlorinated dibenzo-/>dioxins determined by high pressure liquid chromatography, Chemosphere, 14(9) 1267-1274, 1985. 

Friesen, K.J. and Webster, G.R.B. Temperature dependence of the aqueous solubility of highly chlorinated dibenzo-/>dioxins, Environ. Sci. Technol, 24(1) 97-101, 1990. 

This approach was initially developed to estimate the potential toxicity of mixtures of polychlorinated dibenzo- -dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated dioxin-like biphenyls (PCBs). Over the years, a number of different TEF systems for PCDDs, PCDFs and PCBs have been used. A system was internationally agreed upon at a WHO Consultation in 1997 (WHO-TEF) as published by Van den Berg et al. (1998). A WHO update has been published recently (Van den Berg et al. 2006) (Table 10.3). 

Viluksela M et al Subchronic/chronic toxicity of a mixture of four chlorinated dibenzo- -dioxins in rats. I. Design, general observations, hematology, and liver concentrations. Toxicol Appl Pharmacol 151 57, 1998... 

Ankley, G.T., G.J. Niemi, K.B. Lodge, H.J. Harris, D.L. Beaver, D.E. TiUitt, R.R. Schwartz, J.P. Giesy, P.D. Jones, and C. Hagley. 1993. Uptake of planar polychlorinated biphenyls and 2,3,7,8-substituted polychlorinated dibenzofurans and dibenzo-/<-dioxins by birds nesting in the lower Fox River and Green Bay, Wisconsin, USA. Arch. Environ. Contam. Toxicol. 24 332-344. 

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. Spenkehnk, and A. Brouwer. 1994. Biochemical and toxic effects of polychlorinated biphenyls (PCBs), dibenzo-/>-dioxins (PCDDs) and dibenzofurans (PCDFs) in the cormorant (Phalacrocorax carbo) after in ovo exposure. Environ. Toxicol. Chem. 13 803-816. 

Creaser, C.S. and A. Al-Haddad. 1989. Fractionation of polychlorinated biphenyls, polychlorinated dibenzo-/)-dioxins, and polychlorinated dibenzofurans on porous graphite. Anal. Chem. 61 1300-1302. 

Safe, S. 1990. Polychlorinated biphenyls (PCBs), dibenzo-/ -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. 

Zabel, E.W., P.M. Cook, and R.E. Peterson. 1995. Toxic equivalency factors of polychlorinated dibenzo-/)-dioxin, dibenzofuran and biphenyl congeners based on early life stage mortality in rainbow trout (Onco-rhynchus mykiss). Aquat. Toxicol. 31 315-328. 

Hammel, K. E., Kalyanaraman, B. Kirk, T. K. (1986). Oxidation of polycyclic aromatic hydrocarbons and dibenzo[/>]dioxins by Phanerochaete chrysosporium ligninase. Journal of Biological Chemistry, 26l, 16948—52. 

Gold, M. H., Joshi, D. K., Valli, K. Wariishi, H. (1994). Degradation of chlorinated phenols and chlorinated dibenzo-/>-dioxins by Phanerochaelechrysosporium. In B toremed tal ton of Chlorinated and Polycyclic Aromatic Hydrocarbon Compounds, ed. R. E. Hinchee, A. Leeson, L. Semprini S. K. Ong, pp. 231-8. Boca Raton, FL Lewis Publishers. 

Lampi, P., Vartiainen, T., Tuomisto, J. Hesso, A. (1990). Population exposure to chlorophenols, dibenzo- -dioxins and dibenzofurans after a prolonged ground water pollution by chlorophenols. Chemosphere, 20, 625-34. 

Oberg, L. G., Glas, B., Swanson, S. E. Rappe, K. G. (1 >S>0). Peroxidase-catalyzed oxidation of chlorophenols to polychlorinated dibenzo-/>-dioxins and dibenzofurans. Archives of Environmental Contamination and Toxicology, 19, 930-8. 

Pereira, W. E., Rostad, C. E. Sisak, M. E. (1985). Geochemical investigations of polychlorinated dibenzo-/>-dioxins in the subsurface environment at an abandoned wood-treatment facility. Environmental Toxicology and Chemistry, 4, 629-39. 

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