Polychlorinated PCDF dibenzo-furans

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). 

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

Polychlorinated Dibenzo-(p)-Dioxins and Dibenzo-Furans. Another group of compounds that we need to specifically address are the polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzo-furans (PCDFs) (Fig. 2.15). The PCDDs and PCDFs are not intentionally produced but are released into the environment from various combustion processes and as a result of their occurrence as unwanted byproducts in various chlorinated chemical formulations (e.g., chlorinated phenols, chlorinated phenoxy herbicides see Alcock and Jones, 1996). Because some of the PCDD and PCDF congeners are very toxic (e.g., 2,3,7,8-tetrachloro dibenzo-p-dioxin, see margin), there have been and still are considerable efforts to assess their sources, distribution, and fate in the environment. Similarly to the PCBs or DDT (see above), the PCDDs and PCDFs are highly hydrophobic and very persistent in the environment. It is therefore not surprising that they have also been detected everywhere on earth (Brzuzy and Hites, 1996 Lohmann and Jones, 1998 Vallack et al., 1998). Finally, we should note that polybrominated diphenylethers (PBDEs, see margin) that, like the PBBs (see above), are used as flame retardants, are of increasing environmental concern (de Boer et al., 2000). 

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

POPs are widespread in human food productsJ7 An indication of the pervasiveness of POPs is seen from a worldwide study of butter contamination with PCBs, polychlorinated dibenzo-p-dioxins (PCDDs), dibenzo-furans (PCDFs), hexachlorobenzene, and DDT and its metabolites. These POPs were found to be present in varying degrees in the butter of 37 different nations. ... 

As noted earlier, polychlorinated dibenzo dioxins (PCDD) and polychlorinated dibenzo furans (PCDF) are two important classes of potentially toxic by-products that can form in trace levels (e.g., less than parts per... 

NP NPEC OC OP OPEC PCB PCDBT PCDD PCDF PCP PFB RA TCA TCDD TCF TCMTB TOC VSC VOC Nonylphenol Nonylphenol ethoxycarboxylate Organo chlorine Octylphenol Octylphenol ethoxycarboxylate Polychloroinated biphenyls Polychlorinated dibenzothiophene Polychlorin ated dib enzo-p - dioxins Polychlorinated dibenzo-p-furans Pentachlorophenol Pentafluorobenzyl Resin acids 2,4,6-Trichloroanisole Tetrachloro dibenzo dioxin Totally chlorine- free 2-(Thiocyanomethylthio)-benzothiazole Total organic carbon Volatile sulphur compounds Volatile organic compounds... 

Key words Polychlorinated dibenzo-p-dioxins (PCDDs) polychlorinated dibenzo-p-furans (PCDFs) sewage sludge household sewage and municipal wastewater treatment plant (MWTP)... 

Formation of polychlorinated dibenzo(p) dioxins and furans (PCDD/PCDF) in waste combustion has received considerable attention, because dioxins even in very small concentrations are believed to be harmful to humans. Sources of PCDD/PCDF include the waste itself, gas-phase and heterogeneous reactions within the combustion zone, and catalyzed reactions in the low-temperature region downstream [352],... 

Ruokojarvi P, Ettala M, Rahkonen P, Tarhanen J, Ruuskanen J (1995) Polychlorinated Dibenzo-p-dioxins and -Furans (PCDDs and PCDFs) in Municipal Waste Landfill Fires. Chemosphere 30 1697... 

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. 

Ueno, D., Watanabe, M., Subramanian, A., Tanaka, H., Fillmann, G., Lam, P.K., Zheng, G.J., Muchtar, M., Razak, H., Prudente, M., Chung, K.FL, Tanabe, S., 2005. Global pollution monitoring of polychlorinated dibenzo-p-dioxins (PCDDs), furans (PCDFs) and coplanar polychlorinated biphenyls (coplanar PCBs) using skipjack tuna as bioindicator. Environ. Pollut. 136, 303-313. 

Wild SR, Harrad SJ, Jones KC. 1993. The influence of sewage sludge applications to agricultural land on human exposure to polychlorinated dibenzo-p-dioxins (PCDDs) and -furans (PCDFs). Environ Pollution 357-369. 

Dioxin A family of chemicals with related properties and toxicity. There are 75 different dioxins, or polychlorinated dibenzodioxins (PCDDs) 135 different furans, or polychlorinated dibenzofurans (PCDFs) and 209 different polychlorinated biphenyls (PCBs). Each different form is called a congener, a member of a family of compounds known chemically as dibenzo-p-dioxins. Concern about them arises from their potential toxicity as contaminants in commercial products. Tests on laboratory animals indicate that it is one of the more toxic anthropogenic (man-made) compounds a term used interchangeably with 2,3,7,8-tetrachlorodibenzo-p-dioxin or TCDD Disease prevention Measures used to prevent a disease or reduce its severity Dispersoids The particles of a dispersion... 

Fig. 7.25 Chemical structures of the contrasting persistent organic pollutants (POPs), polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and furans (PCDDs/PCDFs), p,p -dichlorodiphenyl trichloroethane (DDT) and hexachlorocyclohexane (HCH). Symbols x and y indicate the possible number of chlorines attached to the ring structures.

To date, there has been little published information on the emissions of substances such as volatile organic compounds (VOC), dioxins (polychlorinated dibenzo-dioxins, or PCDD), furans (polychlorinated dibenzofurans, or PCDF) and heavy metals from lime kilns. 

Figure 11.20 Typical structures of the polychlorinated dibenzo-p-dioxins (PCDDs, i.e., dioxins ), polychlorinated dibenzofurans (PCDFs, i.e., furans ) and polychlorinated...

Dioxin is the widely used term that is used by the public to describe the polychlorinated dibenzo-p-furans (PCDFs) and polychlorinated dibenzo-p-dioxins... 

Polychlorinated Dibenzo Dioxins (PCDDs) and Furans (PCDFs) are also toxic, and their concentrations are limited to low PPB levels by European and US regulations. Trace levels of these substances have been detected in PV 23 and also in chlor-anil, the raw material used to manufacture PV 23. 

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