Chlorinated dibenzodioxines and dibenzofurans

Chlorinated dibenzo-p-dioxines and dibenzofurans are tricyclic aromatic compounds [4], characterized by a high chemical resistance and an ability to be accumulated in the nutritional chain. Some of them are extremely toxic, teratogenic, mutagenic and probably also carcinogenic. The most studied substances in this group are 2,3,7,8-tetrachloro-dibenzodioxine (TCDD) and 2,3,7,8-tetrachloro-dibenzofuran (TCDF), which are among the most toxic substances 

These substances have already caused a number of ecological catastrophes. In 1968 more than 1200 people were poisoned in Japan, by consuming rice oil polluted with 0.1% of commercial polychlorodiphenyl Kanechlor 400. On heating the rice oil, the heating medium (Kanechlor) penetrated through a crack in a heat exchanger into the product. The rice oil became contaminated with 5 ppm of tetra- and pentachloro-dibenzofu-rans and it was shown that the main component was 2,3,7,8-TCDF in a concentration of 0.45 ppm. 

The other prominent case occurred in Sevesa in Italy in 1976. In a factory producing 2,4,5-trichlorophenol by the hydrolysis of 1,2,4,5-tetrachloroben-zene, the reactor content escaped through the safety valve into the atmosphere during an accident. A cloud containing the above-mentioned components and, in addition, a certain amount of 2,3,7,8-TCDD was formed above the factory. It was estimated that approximately 2 to 3 kg of 2,3,7,8-TCDD was spread over an area with a population of several thousand inhabitants. 

Tolgyessy, J., Havranek, E. and Dejmkova, E. Radionuclide X-ray Fluorescence Analysis of Environmental Samples. Elsevier, Amsterdam 1990. 

Brooks, R. P. Geobotany and Biogeochemistry in Mineral Exploration. Harper and Row, New York 1972. 

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SW-846, is used to measure emissions of semivolatile principal organic constituents. Method 0010 is designed to determine destruction and removal efficiency (DRE) of POHCs from incineration systems. The method involves a modification of the EPA Method 5 sampling train and may be used to determine particulate emission rates from stationary sources. The method is applied to semivolatile compounds, including polychlorinated biphenyls (PCBs), chlorinated dibenzodioxins and dibenzofurans, polycyclic organic matter, and other semivolatile organic compounds. 

Zitko, V. 1992. Patterns of 2,3,7,8-substituted chlorinated dibenzodioxins and dibenzofurans in aquatic fauna. 

Commercial PCP preparations often contain variable amounts of chlorophenols, hexachloroben-zene, phenoxyphenols, dioxins, dibenzofurans, chlorinated diphenyl ethers, dihydroxybiphenyls, anisoles, catechols, and other chlorinated dibenzodioxin and dibenzofuran isomers. These contaminants contribute to the toxicity of PCP — sometimes significantly — although the full extent of their interactions with PCP and with each other in PCP formulations are unknown. Unless these contaminants are removed or sharply reduced in existing technical- and commercial-grade PCP formulations, efforts to establish sound PCP criteria for protection of natural resources may be hindered. 

Buser, H.R. Rapid photol34ic decomposition of brominated and brominated/chlorinated dibenzodioxins and dibenzofurans, Chemosphere, 17(5) 899-903, 1988. 

Svenson, A., Kjeller, L-O. Rappe, C. (1989). Enzyme-mediated formation of 2,3,7,8-tetrasubstituted chlorinated dibenzodioxins and dibenzofurans. Environmental Science and Technology, 23, 900—2. 

Svenson A, Kjeller L-O, Rappe C (1989) Enzyme-Mediated Formation of 2,8-Tetra-Sub-stituted Chlorinated Dibenzodioxins and Dibenzofurans. Environ Sci Technol 23 900... 

BuserHR. 1987. Brominated and brominated/chlorinated dibenzodioxins and dibenzofurans Potential environmental contaminants. Chemosphere 16 713-732. 

Gray AP, Cepa SP, Dipinto VM, et al. 1975. Chlorinated dibenzodioxins and dibenzofurans. In Hemphill DD, ed. Trace substances in environmental health-IX. Columbia, MO University of Missouri, 255-263. 

Jasinski JS. 1989. Multiresidue procedures for the determination of chlorinated dibenzodioxins and dibenzofurans in a variety of foods using capillary gas chromatography-electron-capture detection. J Chromatogr 478 349-367. 

Kaminsky LS, DeCaprio AP, Gierthy JF, et al. 1985. The role of environmental matrices and experimental vehicles in chlorinated dibenzodioxin and dibenzofuran toxicity. Chemosphere 14 685-695. 

Schecter A. 1985. Medical surveillance of exposed persons after exposure to PCBs, chlorinated dibenzodioxins and dibenzofurans after PCB transformer or capacitor incidents. Environ Health Perspect 60 333-338. 

Schecter A, Ryan JJ, Lizotte R, et al. 1985a. Chlorinated dibenzodioxins and dibenzofurans in human adipose tissue from exposed and control New York State patients. Chemosphere 14 933-937. 

Zitko V. 1989a. A graphical presentation of the composition and properties of chlorinated dibenzodioxins and dibenzofurans. Sci Total Environ 83 191-194. 

Zitko V. 1989b. Composition of chlorinated dibenzodioxins and dibenzofurans in various samples. Sci Total Environ 80 127-137. 

Zitko V, Hutzinger O, Choi PMK. 1972. Contamination of the Bay of Fundy - Gulf of Maine area with polychlorinated biphenyls, polychlorinated terphenyls, chlorinated dibenzodioxins, and dibenzofurans. Environ Health Perspect 1 47-50. 

Exposure by multiple routes is assumed to be additive. The default assumption is that simultaneous exposure to multiple agents having the same site or mode of action results in additive effects. Thus, for example, estimates of the developmental toxicity of chlorinated dibenzodioxins and dibenzofurans should consider the use of toxic equivalency factors (Safe 1993), provided the quantitative value assigned to each congener is relevant to the toxic effect under consideration. 

Weber R, Hagenmaier H (1995), Organohalogen Compounds 23 357-362. Mixed chlorinated fluorinated dibenzodioxins, dibenzofurans, biphenyls synthesis, analysis and formation", Eds. Dioxin 95 Secretariat, Edmonton, Kanada ISBN 3-928379-13-5 Zitko V (1985), Chemosphere 14 165. Shorthand numbering of chlorinated dibenzodioxins and dibenzofurans"... 

Figure 3.4 General structures for chlorinated dibenzodioxins and dibenzofurans, together with the most toxic dioxin congener TCDD.

Ritter, E.R. Bozzelli, J.W. Pathways to chlorinated dibenzodioxins and dibenzofurans from partial oxidation of chlorinated aromatics by OH radical—thermodynamic and kinetic insights. Combust. Sci. Tech. 1994, 101, 153-169. 

Beilin, J.S. and Barnes, D.G. (1985). Procedures for estimating risks associated with exposures to mixtures of chlorinated dibenzodioxins and -dibenzofurans (CDDs... 

Procedures of Estimating Risks Associated with Exposure to Mixtures of Chlorinated Dibenzodioxins and Dibenzofurans", U.S. Environmental Protection Agency, 1985. 

Dickson, L. C., D. Lenoir, and O. Hutzinger. 1988. Surface-catalyzed formation of chlorinated dibenzodioxins and dibenzofurans during incineration. Chemosphere 79(1-6) 277-88. 

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