Polychlorinated dibenzodioxins sources

Investigations have shown that plants on thermal treatment of solid domestic waste represent the source of polychlorinated dibenzodioxins and biphenyls. In this connection, it is necessary to conduct further investigations of their emission and determination of all the range of PCDD, PCDF and PCB... 

Zook DR, Rappe C Environmental sources, distribution, and fate of polychlorinated dibenzodioxins, dibenzofurans, and related organochlorines. In Schecter A (ed.) Dioxins and Health, 80pp. New York, Plenum Press, 1994... 

The sources of unintentionally produced POP chemicals, polychlorinated dibenzodioxins (PCDD), polychlorinated dibenzofurans (PCDF), and hexachlorobenzene (HCB), has been estimated through the National Implementation Plan (NIP) for Malaysia. However, an official report has not been made public. The draft final report on the assessment of unintentionally produced chemicals conducted by Universiti Sains Malaysia... 

Tieman TO, Taylor ML, Garrett JH, et al. 1985. Sources and fate of polychlorinated dibenzodioxins, dibenzofurans and related compounds in human environments. Environ Health Perspect 59 145-158. 

Polychlorinated dibenzodioxins and polychlorinated dibenzofurans (PCDDs/PCDFs), polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs) are now ubiquitous in the environment. Their occurrence in indoor air mainly results from the frequent use of chemical products such as paints, glue, sealants, fire retardants and wood protection agents up to the mid-1980s. Furthermore, PCDDs/PCDFs and PAHs are always formed to some extent during incomplete combustion processes. A list of possible sources is given in Table 1.4-1. 

PCBs and PCDDs. In Diarylide Yellow manufacture, the use of formate buffer to enhance pigment transparency for offset ink was discontinued in the nineteen seventies, when it was realized that polychlorinated biphenyls were being produced as an undesirable by-product of the coupling reaction. In Phthalocyanine Blue crude synthesis, the commonly used solvent, trichlorobenzene, was also discontinued in the US, as a potential source of poly-chlorinated biphenyls. More recently, use of chloranil, manufactured from chlorinated phenols, has been discontinued in the synthesis of dioxazine violet crude and sulfonated dioxazine acid dyes, so as to minimize by-product formation of polychlorinated dibenzodioxins and dibenzofurans (PCDDs/PCDFs). A new grade ofhigh purity chloranil is now produced from hydroquinone for dye and pigment manufacture. 

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. 

This chapter is divided into seven main sections. The first of these sections is focused on technological contaminants, namely heterocyclic amines, acrylamide, furan, chloropropanok and their fatty acid esters, polycycKc aromatic hydrocarbons, monocyclic aromatic hydrocarbons, nitroso compounds, and ethyl carbamate. Other sections deal with microbial toxins (mycotoxins and bacterial toxins), persistent organohalogen contaminants (such as polychlorinated biphenyls, dibenzodioxins and dibenzofurans), chlorinated ahphatic hydrocarbons, pesticides (persistent chlorinated hydrocarbons and modem pesticides), veterinary medicines and contaminants from packaging materials. Presented for each of these contaminants are structures, properties, occurrence and the main sources of dietary intake, mechanisms of formation, possibilities of food contamination, prevention and mitigation and health and toxicological evaluations. 

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