Dioxins and Dibenzofurans

The cellular slime mold Dictyostelium purpureum K1001 contains AB0022A (2255), a novel antibacterial dibenzofuran, the structure of which was confirmed by total synthesis (2038). The lichen Lecanora cinereocarnea has yielded several new dibenzofurans, including three chlorinated analogues (2256-2258) (2039), and Lecanora iseana contains 2259 and 2260 (2040). The first naturally occurring polybrominated dibenzofuran, corallinafuran (2261), is present in a crustose coralline red alga that also contains corallinaether (1913) cited earlier (1769). 

Similarly, polychlorinated dioxins and furans form in both compost and sewage sludge (1), but the major congeners in both systems are heptachloro- and octa-chlorodibenzo-p-dioxins and their origin is not understood (2052-2056). Several studies have attempted to elucidate the importance of natural combustion events as a source of polychlorinated dioxins and furans (1), but recent reports indicate that forest fires may not be a significant source of these compounds (227, 2057) despite earlier suggestions to the contrary (1, 2058, 2059). Nevertheless, numerous studies (wood stoves, control bums, etc.) clearly demonstrate that the combustion of wood 

Myeloperoxidase-induced dioxin formation from chlorophenols (2046, 2047). 

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Depending on the desired application, additional refining may be necessary. For demagging (removal of magnesium from the melt), hazardous substances such as chlorine and hexachloroethane are often used, which may produce dioxins and dibenzofurans. Other, less hazardous methods, such as adding chlorine salts, are available. 

M. Freiberg, D.L. McAllister, C.J. Mazac, P. Ranken Analysis of Trace Levels of Polybrominated Dibenzo-p-dioxins and Dibenzofurans in Brominated Flame Retardants Presented on June 30, 1993 at Orgabrom 93 in Jerusalem. 

Fleischer 0, Wichmann H, Lorenz W. 1999. Release of polychlorinated dibenzo-p-dioxins and dibenzofurans by setting off fireworks. Chemosphere 39(6) 925-932. 

FIGURE 7.1 Formation of dioxin and dibenzofuran (from Crosby 1998). 

Rappe, C., Nygren, M., and Linstrom, G. et al. (1987). Overview on environmental fate of chlorinated dioxins and dibenzofurans sources levels and isomeric pattern in various matrices. Chemosphere 16, 1603-1618. 

For polychlorinated biphenyls (PCBs), rate constants were highly dependent on the number of chlorine atoms, and calculated atmospheric lifetimes varied from 2 d for 3-chlorobiphenyl to 34 d for 236-25 pentachlorobiphenyl (Anderson and Hites 1996). It was estimated that loss by hydroxy-lation in the atmosphere was a primary process for the removal of PCBs from the environment. It was later shown that the products were chlorinated benzoic acids produced by initial reaction with a hydroxyl radical at the 1-position followed by transannular dioxygenation at the 2- and 5-positions followed by ring fission (Brubaker and Hites 1998). Reactions of hydroxyl radicals with polychlorinated dibenzo[l,4]dioxins and dibenzofurans also play an important role for their removal from the atmosphere (Brubaker and Hites 1997). The gas phase and the particulate phase are in equilibrium, and the results show that gas-phase reactions with hydroxyl radicals are important for the... 

Concern has been expressed over the formation of chlorinated dibenzo[l,4]dioxins and dibenzofurans during the thermal transformation of organic material in the presence of chloride or organochlorine compounds. 

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. 

Naturally occurring oxaarenes based on polycyclic pyrans encompass a plethora of structures including the plant polyphenols such as anthocyanins and a-tocopherol (vitamin E). Halogenated dibenzo-p-dioxins and dibenzofurans are formed both as by-products during the manufacture of chlorophenols, and from the incineration of organic matter in the presence of inorganic halides. 

Adriaens P, Q Fu, D Grbic-Galic (1995) Bioavailability and transformation of highly chlorinated dibenzo-p-dioxins and dibenzofurans in anaerobic soils and sediments. Environ Sci Technol 29 2252-2260. 

Elliott JE, Machmer MM, Henny CJ, Wilson LK, Norstrom RJ. 1998. Contaminants in ospreys from the Pacific Northwest. 1. Trends and patterns in polychlorinated dibenzo-p-dioxins and -dibenzofurans in eggs and plasma. Arch Environ Contam Toxicol 35 620-631. 

Fraser CA, Gardner GJ, Maxwell PS, Kubwabo C, Guevremont R, Siu KWM, and Berman SS (1995) Preparation and certification of a biological reference material (CARP-i) for polychlorinated dibenzo-p-dioxin and dibenzofuran congeners. Fresenius J Anal Chem 352 143-147. Gahr A, Huber N, and Niessner R (1998) Fluorimetric determination of bromate by ion-exchange separation and post-column derivatization. Mikrochrm Acta 129 281-290. 

Hashimoto, S., Ito, H., and Morita, M., Elution of polychlorinated dibenzo-p-dioxins and dibenzofurans from coffee filters, Chemosphere, 25(3), 297, 1992. (CA118 21237c)... 

Wang, L., Lee, W., Tsai, P, Lee, W., and Chang-Chien, G., Emissions of polychlorinated dibenzo-p-dioxins and dibenzofurans from stack flue gases of sinter plants, Chemosphere, 50(9), 1123-1129, 2003. 

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]. 

Table 1 Concentrations of chlorinated polycyclic aromatic hydrocarbons (CIPAHs), polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), polybrominated biphenyls (PBBs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) in ambient air, soil, and human samples collected from e-waste recycling and reference sites in China... 

Ma J, Kannan K, Cheng J, Horii Y, Wu Q, Wang W (2008) Concentrations, profiles, and estimated human exposures for polychlorinated dibenzo-p-dioxins and dibenzofurans from electronic waste recycling facilities and a chemical industrial complex in Eastern China. Environ Sci Technol 42(22) 8252-8259. doi 10.1021/es8017573... 

Wen S, Yang F, Li JG, Gong Y, Zhang XL, Hui Y, Wu YN, Zhao YF, Xu Y (2009) Polychlorinated dibenzo-p-dioxin and dibenzofurans (PCDD/Fs), polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyls (PCBs) monitored by tree bark in an e-waste recycling area. Chemosphere 74(7) 981-987. doi 10.1016/j.chemosphere.2008.10.002... 

Cheney, B. V. 1982. Structural Factors Affecting Aryl Hydrocarbon Hydroxylase Induction of Dibenzo-p-Dioxins and Dibenzofurans. Int. J. Quant. Chem. 21,445. 

Broman, D., Naf, C., Rolff, C., Zebuhr, Y. (1991) Occurrence and dynamics of polychlorinated dibenzo-p-dioxins and dibenzofurans and polycyclic aromatic hydrocarbons in the mixed surface layer of remote coastal and offshore waters of the Baltic. Environ. Sci. Technol. 25, 1850-1864. 

Brubaker, Jr. W.W., Hites, R.A. (1998) OH reaction kinetics of polycyclic aromatic hydrocarbons and polychlorinated dibenzo-p-dioxins and dibenzofurans. J. Phys. Chem. A 102, 915-921. 

Mackay, D., Shiu, W.Y., Ma, K.C. (1992b) Illustrated Handbook of Physical-Chemical Properties and Environmental Fate for Organic Chemicals. Vol. 2, Polynuclear Aromatic Hydrocarbons, Polychlorinated Dioxins, and Dibenzofurans. Lewis Publishers, Inc., Chelsea, Michigan. 

Sangster, J. (1989) Octanol-water partition coefficients of simple organic compounds. J. Phys. Chem. Ref. Data 18, 1111-1230. Sangster, J. (1993) LOGKOW, A Databank of Evaluated Octanol-Water Partition Coefficients. 1st Edition, Montreal, Quebec, Canada. Sarna, L.P., Hodge, P.E., Webster, G.R.B. (1984) Octanol-water partition coefficients of chlorinated dioxins and dibenzofurans by reversed-phase HPLC using several C18 columns. Chemosphere 13, 975-983. 

Data from Hardell, L. 1983. Epidemiological studies on soft-tissue sarcoma, malignant lymphoma, nasal and nasopharyngeal cancer, and their relation to phenoxy acid or chlo-rophenol exposure. Pages 367-374 in G. Choudhary, L.H. Keith, and C. Rappe (eds.). Chlorinated Dioxins and Dibenzofurans in the Total Environment. Butterworth, Woburn, MA. 

Czuczwa, J.M., B.D. McVeety, and R.A. Hites. 1984. Polychlorinated dibenzo-p-dioxins and dibenzofurans in sediments from Siskiwit Lake, Isle Royale. Science 226 568-569. 

Muir, D.C.G., C.A. Ford, B. Rosenberg, R.J. Norstrom, M. Simon, and P. Beland. 1996. Persistent organochlo-rines in beluga whales (Delphinapterus leucas) from the St Lawrence River estuary. I. Concentrations and patterns of specific PCBs, chlorinated pesticides and polychlorinated dibenzo-p-dioxins and dibenzofurans. Environ. Pollut. 93 219-234. 

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. 

Neubert, R., G. Golor, R. Stahlmann, H. Helge, and D. Neubert. 1992. Polyhalogenated dibenzo-p-dioxins and dibenzofurans and the immune system. 4. Effects of multiple-dose treatment with 2,3,7,8-tetrachloro-dibenzo-p-dioxin (TCDD) on peripheral lymphocyte subpopulations of a non-human primate (Callithrix jacchus). Arch. Toxicol. 66 250-259. 

Olie, K., A. Schecter, J. Constable, R.M.M. Kooke, P. Seme, P.C. Slot, and P. de Vries. 1989. Chlorinated dioxin and dibenzofuran levels in fish and wildlife samples in the north and south of Vietnam. Chemosphere 19 493-496. 

Spear, P.A., D.H. Bourbonnais, R.J. Norstrom, and T.W. Moon. 1990. Yolk retinoids (Vitamin A) in eggs of the herring gull and correlations with polychlorinated dibcnzo-p-dioxins and dibenzofurans. Environ. Toxicol. Chem. 9 1053-1061. 

Stalling, D.L., L.M. Smith, J.D. Petty, J.W. Hogan, J.L. Johnson, C. Rappe, and H.R. Buser. 1983. Residues of polychlorinated dibenzo-p-dioxins and dibenzofurans in Laurentian Great Lakes fish. Pages 221-240 in R.E. Tucker, A.L. Young, and A.P. Gray (eds.). Human and Environmental Risks of Chlorinated Dioxins and Related Compounds. Plenum Press, New York. 

Van Scheppingen, W.B., A.J.I.M. Verhoeven, P. Mulder, M.J. Addink, and C. Smeenk. 1996. Polychlorinated biphenyls, dibenzo-p-dioxins, and dibenzofurans in harbor porpoises (Phocoena phocoena) stranded on the Dutch coast between 1990 and 1993. Arch. Environ. Contam. Toxicol. 30 492-502. 

World Health Organization (WHO). 1989. Polychlorinated Dibenzo-para-dioxins and Dibenzofurans. Environmental Health Criteria 88. WHO, Geneva. 409 pp. 

Exposure studies of individual species to specific congeners alone or in combination with other compounds, including other PCB congeners, dioxins, and dibenzofurans... 

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