Chlorinated dibenzo dioxin

Table II. Composition of Products during the Purification of Chlorinated Dibenzo-/ -dioxin...

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

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. 

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. 

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... 

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. 

A toxicological profile for chlorinated dibenzo-/ -dioxins was released in February 1998. This edition supersedes any previously released draft or final profile. 

The primary purpose of this chapter is to provide public health officials, physicians, toxicologists, and other interested individuals and groups with an overall perspective of the toxicology of chlorinated dibenzo-/ -dioxins (CDDs). 

IARC, Monograph on the Evaluation of Carcinogenic Risk of Chemicals in Man, Vol. 15, Some Fumigants, the Herbicides 2,4-D and 2,4,5-T, Chlorinated Dibenzo-dioxins and Miscellaneous Industrial Chemicals, International Agency for Research on Cancer, Lyon, France, 1974. 

The large number of potential congeners and isomers of some semivolatile compounds is illustrated in Table 8.1 which shows the numbers of possible chlorinated biphenyl, chlorinated dibenzo-/ -dioxin, and chlorinated dibenzofuran congeners and isomers. The total number of chlorinated congeners of each parent compound is the sum of the possible isomers at each level of chlorination. Dibenzofuran has more possible chlorinated congeners and isomers than chlorinated dibenzo-/ -dioxin (Fig. 8.2) because it has just one ring oxygen and a less symmetrical structure. If F, Br, I, CH3 or any other uniform... 

Buser HR (1987), Chemosphere 16 713-732. Brominated and brominated/chlorinated dibenzo-dioxins and dibenzofurans Potential environmental contaminants"... 

Estimation of Relative Toxic ities (2,3,7,8-TCDD Equivalents) of Various Chlorinated Dibenzo- -dioxins... 

A06. Berry, D.L., T.J. Slaga, J. DiGiovanni, and M.R. Juchau Chlorinated dibenzo-/)-dioxins, polybrominated biphenyls, and polychlorinated biphenyls in a two-stage system of mouse skin tumorigenesis Potent anticarcinogenic effects Ann. NY Acad. Sci. 320 (1979) 405 14. 

The distribution of chemicals onto the foliar surface can occur by vapor-phase transfer, particle deposition (wet or dry), or from aqueous solution, which would be negligible for most organic compounds. It has been established that dry gaseous uptake is the predominant pathway for the foliar uptake of relatively nonvolatile compounds such as the chlorinated dibenzo-dioxins and -furans." The distribution of compounds between air and the cuticular polymer matrix follows Henry s law (Fig. 3.22)." This conclusion was drawn from observation of how a series of 50 low molecular weight (<175) compounds distributed between the vapor phase... 

S Halogenated Compounds Many halogenated compounds, either because of their extensive use or their persistence are of environmental interest. The smaller, halogenated aliphatics have been used extensively and are common ground water contaminants," while the persistence of the PCBs and chlorinated dibenzo dioxins is well documented. Hydroxyl radicals are the more important oxidants in the vapor phase and the hydrocarbon structure determines the nature of the reaction. Second-order rate constants for some of these compounds are summarized in Table 6.27. 

Lamparski, L.L., R.H. Stehl, andR.L. Johnson. Photolysis of Pentachlorophenol-Treated Wood. Chlorinated Dibenzo-/ -dioxin Formation, Environ. Sci. Technol, 14(2) 196-200 (1980). 

There has been considerable concern throughout Europe about the incineration of wastes, yet in Japan about 70% of all MSW is incinerated, and plans are that this should increase to 90% by the year 2000 [33]. Incinerators that are poorly operated may run at temperatures too low to burn potentially hazardous intermediates of the combustion process such as the products from pyrolysis which are believed to be the precursors in the combustion processes [34]. Of particular concern has been the discovery of extremely toxic materials such as dioxins (chlorinated dibenzo-/ -dioxins and benzofuran dioxins), in the flue gases of some incinerators. Such is the level of concern that many European countries have increased the legislative and environmental controls on incinerator operators, and some are moving to ban the incineration of plastics [35], and particularly PVC. In incinerators where the temperature is below about 1400 K, dehydrochlorination of PVC occurs, accompanied by the formation of polyenes. The polyenes can then cyclise and be oxidised, and then be attacked by chlorine-containing species to produce dioxins, the most toxic of which is 2,3,7,8-tetra-chlorodibenzo-/7-dioxin (TCDD), the material at the centre of the disaster at Sveso, Northern Italy, in 1979. More than 70 dioxins are known to exist (Figure 13.11). 

The Hazards Substance Ordinance in Germany specifies the maximum level of chlorinated dibenzo-dioxins and furans that can be present in materials marketed in Germany. This has been extended to the brominated compounds. The two largest volume flame retardants decabromodiphenyl oxide and tetrabromo his-phenol A - are said to meet these requirements [1,2]. 

Arsenault, R.D. 1976. Pentachlorophenol and contained chlorinated dibenzo-dioxins in the environment a study of environmental fate, stability, and significance when used in wood preservation. Presented at the American Wood-Preservers Association Annual Meeting, Atlanta, Georgia, April 25-28. pp. 122-148. 

Dobbs, A.J., and C. Grant. 1979. Photolysis of highly chlorinated dibenzo-/ -dioxins by sunlight. Nature 278 163-165. 

Taylor, P.H., T. Yamada, and A. Neuforth (2005), Kinetics of OH radical reaction with dibenzo-/>-dioxin and selected chlorinated dibenzo-/ -dioxins, Chemosphere, 58, 243-252. 

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