Polychlorinated dibenzo-/ -dioxins

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). 

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. 

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. 

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... 

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). 

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. 

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). 

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. 

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. 

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. 

In several tests on compound sets that are structurally very different from the training set, including a larger set of pesticide molecules, Eq. (10.3) proved to be very robust and transferable. Recently, the method was applied to polychlorinated dibenzo-/)-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) [137]. As shown in Fig. 11.3. it was found that the COSMO-RS predictions appear to be even more accurate than the experimental data, especially at the low-solubility end. While the experimental results for many compounds show a scatter of more than a... 

At the same time the issues related to the unintentionally produced dioxins and furans, i.e., polychlorinated dibenzo- -dioxins (PCDDs) and PCDFs, attracted public attention in 1983 when investigations revealed that dioxins were detected in the fly ashes from municipal waste incinerators. Therefore, measures to monitor dioxins in the bottom sediment and aquatic animals and plants in the rivers, lakes, marshes and seawaters as well as the atmosphere were initiated in 1986. Investigations were implemented on the actual status of waste incinerators in 1984 and pulp and paper factories in 1990. On the basis of these findings, guidelines and administrative guidance on controlling emissions of dioxin-related chemicals were derived and established. 

Yamagishi, T., Miyazaki, T., Akiyama, K., Morita, M., 1981. Polychlorinated dibenzo-/ -dioxins and dibenzofurans in commercial diphenyl ether herbicides, and in freshwater fish collected from the application area. Chemosphere 10, 1137-1144. 

Yamashita, N., Kannan, K., Imagawa, T., Villeneuve, D.L., Hashimoto, S., Miyazaki, A., Giesy, J.P., 2000. Vertical profile of polychlorinated dibenzo-/ -dioxins, dibenzofurans, naphthalenes, biphenyls, polycyclic aromatic hydrocarbons, and alkylphenols in a sediment core from Tokyo Bay, Japan. Environ. Sci. Technol. 34, 3560-3567. 

Im, S.H., Strause, K.D., Giesy, J.P., Chang, Y.S., Matsuda, M., Wakimoto, T., 2004. Concentrations and accumulation profiles of polychlorinated dibenzo-/ -dioxins and dibenzofurans in aquatic tissues, and ambient air from south Korea. Chemosphere 55, 1293-1302. 

Polychlorinated Dibenzo-/ -Dioxins, Dibenzofurans, and Biphenyls, and Polybrominated Diphenyl Ethers in China ... 

Published data on PCDD/Fs in the environment of the PRD is still limited. A short-term sampling scheme was conducted to determine the levels of particle-bound polychlorinated dibenzo- -dioxins and dibenzofurans (PCDD/Fs) in Guangzhou atmosphere and evaluate the impact of PCDD/ Fs to inhabitants. Samples were collected from four different districts of Guangzhou. The results showed that industrial activities had more influences on levels of PCDD/Fs in the sampled districts. The mean PCDD/Fs concentrations (i.e., mean I-TEQ values) of Huadu district, Liwan district, Tianhe district and Huangpu district were 3815-26,530 fg m-3 (104.6-769.3 fgl-TEQ m-3). Emission source analysis indicated that small diffuse sources were relatively important (Yu et al., 2006). 

The Stockholm Convention is a global treaty committing the international community to protecting human health and the environment from the potentially harmful effects of POPs (UNEP Chemicals, 2005). The United Nations Environment Programme (UNEP) has identified 12 most toxic POPs (the Dirty Dozen ) for control under the Convention, including 10 intentionally produced POPs pesticides/industrial chemicals (aldrin, chlordane, DDT, dieldrin, endrin, heptachlor, hexachlorobenzene (HCB), mirex, toxaphene and polychlorinated biphenyls (PCBs)) and two unintentionally produced POPs by-products (polychlorinated dibenzo-/ -dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs)). In implementing the Convention, Parties to the Convention will take measures to restrict the trade, production and use of the intentional POPs and to reduce and, where possible, to ultimately eliminate the production and release of the unintentional POPs by-products. 

Table 8.9. Polychlorinated dibenzo-/ -dioxins/ dibenzo-/ -furans (PCDDs/PCDFs) concentrations in bird samples from different countries... 

DDTs), hexachlorocyclohexane isomers (HCHs), chlordane compounds (CHLs) and hexachlorobenzene. Residues levels of industry-derived contaminants such as polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-/>-dioxins and dibenzofurans (PCDD/Fs) were also reviewed. Concentrations of these contaminants in different environmental compartments were expressed as unit equivalent to part-per-billion (ppb) level, unless otherwise specified. The cited values of concentrations from various literature sources were rounded to two significant digits for comparison. A number of factors can influence the concentrations in biological samples. Therefore, whenever possible, for biological samples the lipid normalized concentrations were cited for comparison. 

Wagrowski, D.M., Hites, R.A., 2000. Insights into the global distribution of polychlorinated dibenzo-/)-dioxins and dibenzofurans. Environ. Sci. Technol. 34, 2952-2958. 

Wang, Y.H., Wong, P.K. (2002) Mathematical relationships between vapor pressure, water solubility, Henry s law constant, n-octanol/water partition coefficient and gas chromatographic retention index of polychlorinated-dibenzo-dioxins. Water Res. 36, 350-355. 

Barring, H., Bucheli, T.D., Broman, D., Gustafsson, 6. (2002) Soot-water distribution coefficients for polychlorinated dibenzo-/ -dioxins, polychlorinated dibenzofurans and polybrominated diphenylethers determined with the soot cosolvency-column method. Chemosphere 49, 515-523. 

Pignatello JJ, Huang FQ. Degradation of polychlorinated dibenzo-/>-dioxin and dibenzofuran contaminants in 2,4,5-T by photoassisted iron-catalyzed hydrogen peroxide. Water Res 1993 27 1731-1736. 

Phase-transfer catalysis in the chemistry of 1,3-dioxanes 92MI8. Polychlorinated dibenzo-/ -dioxines 91CLY158. 

It has been argued466 that the solution photolysis rates of polychlorinated dibenzo-/ -dioxins may be explained by the preferential photodissociation of chlorine atoms from a lateral vs a non-lateral position to yield the corresponding aryl radical and/or aryl cation-aryl carbene intermediate. 

Laine, M.M., Ahtiainen, J., Wagman, N., Oberg, L.G., and Jprgensen, K.S. 1997. Fate and toxicity of chlorophenols, polychlorinated dibenzo-/ -dioxins, and dibenzofurans during composting of contaminated sawmill sod. Environmental Science and Technology, 31 3244-50. 

Brzuzy, L. P., Hites, R. A. Estimating the atmospheric deposition of polychlorinated dibenzo-/)-dioxins from soils. Environmental Science and Technology, 29(8) 2092-2098 (1995). 

Venier, M., Ferrario, J., et al. (2009) Polychlorinated dibenzo-/)-dioxins and dibenzofurans in the atmosphere around the Great Lakes. Environmental Science and Technology, 43(4) 1036-1041. 

Baker J. I. and Hites R. A. (2000b) Siskiwit Lake revisited time trends of polychlorinated dibenzo-/)-dioxin and diben-zofuran deposition at Isle Royale, Michigan. Environ. Set Technol 34, 2887-2891. 

Barkovskii A. L. and Adriaens P. (1998) Affect of model humic constituents on microbial reductive dechlorination of polychlorinated dibenzo-/)-dioxins. Environ. Toxicol. Chem. 17, 1013-1021. 

A. Bignert, M. Olsson, P.-A. Bergqvist, S. Bergek, C. Rappe, C. de Wit. B. Jansson, Polychlorinated dibenzo-/)-dioxins (PCDD) and dibenzofurans (PCDF) in seal blubber, Chemosphere, 19 (1989), 551-556. 

---