Polychlorinated dibenzofurans

Group of isomers with the same carbon skeleton and number of chlorines, e.g., TeCDDs Rat hepatoma cell line Polychlorinated biphenyls Polychlorinated dibcnzo-p-dioxin Polychlorinated dibenzofuran Polychlorinated dibenzo-p-dioxin and -furan Tetrachlorodibenzo-p-dioxin (-furan) Pentachlorodibenzo-p-dioxin ( furan) Hexachlorodibenzo-p-dioxin (-furan) Heptachlorodibenzo-p-dioxin ( furan)... 

Lead, cadmium, mercury, cobalt, uranium, antimony, barium, beryllium, cesium, molybdenum, platinum, thallium, tungsten, organochlorine pesticides, organophospho-rus insecticides (dialkyl phosphate metabolites), (specific metabolites), pyrethroid pesticides, other pesticides (2-isopropoyxyphenol, carbofuranphenol), herbicides, phthalates, phytoestrogens, polycyclic aromatic hydrocarbons, polychlorinated dibenzo-p-dioxins and dibenzofurans, polychlorinated biphenyls, tobacco smoke... 

Halogens and their covalent compounds Metal carbonyls Organometallic compounds Oxidizing agents Polychlorinated dibenzofuran Polychlorinated dibenzo-p-dioxin... 

Chloracne was first reported by Von Bettman in 1897. In 1899, Herxheimer used the term chloracne to describe four cases of severe acne resulting from environmental contact with electrolytically produced potassium hypochlorite. Since that time, various chloracnegenic chemicals have been identified. Chlo-ronapthalenes and polychlorinated biphenyls (PCBs) were the causative agents in the pre-World-War-II era. Since then, trace contaminants formed during the manufacture of PCBs and other polyhalogenated compounds, especially herbicides, have been the major causes of chloracne. These include polyhalogenated dibenzofurans, polychlorinated dibenzo-p-dioxins and chlorinated azo- and azoxy benzenes. 

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). 

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. 

A second sampling program in Southern California sampled for polychlorinated dioxins and polychlorinated dibenzofurans at seven locations (9). Because of the semivolatile nature of these compounds, a tandem sampler was used with a glass fiber filter to collect the particulate-associated compo-... 

TCDD is the most potent inducer of chloracne. This has been well known since the accident in Seveso, Italy, in 1976 in which large amounts of TCDD were distributed in the environment subsequent to an explosion in a factory that produced a chlorophenoxy herbicide, 2,4,5-T. TCDD is an impurity produced during the production of 2,4,5-T. The most common long-term effect of TCDD exposure was chloracne. Exposed individuals also suffered increased excretion of porphyrins, hyper-pigmentation, central nervous system effects, and liver damage and increased risk of cancer was a long-term consequence of the exposure. In addition to TCDD, polychlorinated biphenyls (PCBs), polychlorinated dibenzofurans, and polychloronaphthalens cause chloracne as well as other effects typical of TCDD. 7i... 

Ecological danger of polychlorinated dibenzodioxines and dibenzofurans 97MI26, 97MI45, 98MI33, 98MI34. 

Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in marine products and estimation of exposure through fishes and shellfishes 97YZ850. 

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). 

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

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... 

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. 

Kuzuhara S, H Sato, N Tsubouchi, Y Ohtsuka, E Kasai (2005) Effect of nitrogen-containing compounds on polychlorinated dibenzo-p-dioxin/dibenzofuran formation through de novo synthesis. Environ Sci Technol 39 795-799. 

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. 

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. 

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. 

Eljarrat E, De La Cal A, Larrazabal D, Fabrellas B, Femandez-Alba AR, Borrull F, Marce RM, Barcelo D (2005) Occurrence of polybrominated diphenylethers, polychlorinated dibenzo-p-dioxins, dibenzofurans and biphenyls in coastal sediments from Spain. Environ Pollut 136(3) 493-501... 

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