Dioxins, environmental pollution

Keywords Dioxins, Environmental Pollution, Nanoparticles, Neurotoxicity, Thyroid disrupters... 

Brunstrom, B., M. Engwall, K. Hjelm, L. Lindqvist, and Y. Zebuhr. 1995. EROD induction in cultured chick embryo liver a sensitive bioassay for dioxin-like environmental pollutants. Environ. Toxicol. Chem. 14 837-852. 

Incineration of domestic waste is also a contributor to environmental pollution. One more source of dioxins is pulp-and-paper industry. Comparatively new ways of forming polychlorinated dibenzo-p-dioxins and furans are high-temperature processes like copper melting in electric arc furnaces, and production of magnesium, nickel and, possibly, other metals of their chlorides. 

R. I. Pervunina, D. P. Samsonov, V. P. Kiryuhin. Studying of Environmental Pollution with Dioxin and Related Compounds in Cities and Regions of Russia (1988-1996). - In the book Dioxins - XXI Century Supertoxicants.- Regions of Russia.- News bulletin No.3.-Moscow, 1998, p.64-81. 

M. G. Prodanchuk, V. I. Medvedev, R. Yu. Sova. - Evaluation of Threat of Environmental Pollution with Dioxins and Biphenyls under Thermal Treatment of Solid Domestic Waste. In the book Cleanness of the Environment in Our City.- Theses of Reports.- Ukraine, Lviv.- 1999.-p.l6-18... 

Bunce, N. J., Petrulis, J. R. (1999). Dioxin-like compounds screening assays. In Meyers R. A. (Ed.). Encyclopedia of Environmental Pollution and Cleanup, Wiley, NY, pp 440-449... 

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). 

EC, especially when combined with GC-MS, is widespread in monitoring environmental pollutants such as toxaphene, [72] dioxins, [74,79,82,84] pesticides, [79] halogenated metabolites, [71] DNA adducts, [78] explosives, [66,85,86] and others. [68,69,87,88]... 

Another development is due to the interest in polychlorodibenzofurans, spurred by their occurrence as environmental contaminants. Polychloro-phenols are manufactured in large amounts (150,000 tons per annum) and find a wide range of uses. The usual method of manufacture involves the hydrolysis of chlorobenzenes, and side reactions, favored by high temperature, can lead to the production of polychlorodibenzofurans and poly-chlorodibenzo-p-dioxins. The Seveso incident is well known." Polychloro-biphenyls are also widely used industrial chemicals, particularly in heat exchange systems, and their pyrolysis leads to the formation of polychloro-dibenzofurans. Polychlorodibenzofurans have also been detected in the fly ash and flue gases of incinerators and industrial heating plants. The most toxic of the polychlorodibenzofurans are 2,3,7,8-tetra-, 1,2,3,7,8-penta-, and 2,3,4,7,8-pentachlorodibenzofuran, and an extensive literature exists on the environmental pollution and the results of human exposure to these substances. A particularly tragic example of the latter occurred in 1968 in the Fukuoka prefecture of Japan after consumption of rice oil contaminated with a commercial polychlorobiphenyl. 

Despite the strengthening of environmental policies, problems in relation to cadmium and cyanide, dioxin, organic pollution, lake eutrophication, residential sewage, pesticide runoff, industrial discharges, and groundwater contamination by toxics and nitrates also need to be tackled. 

Another notable class of persistent organohalide compounds is the polychlorinated biphenyl (PCB) class, discussed in Section 16.4. Widely used in industrial applications, these compounds have become widespread and persistent environmental pollutants. The compound 2,3,7,8-tetrachlo-rodibenzo-p-dioxin (TCDD), commonly known as dioxin, discussed in Section 16.6, is an extremely persistent manufacturing by-product that has caused significant environmental problems. 

Campbell AD, Firestone D, Westly B. 1971. Chick edema factor—toxic dioxins. In WestleyB, ed. International Symposium on identification and measurement of environmental pollutants, Ottawa, Ontario, Canada, June 14-17, 1971. Ottawa, Canada The Symposium, 105-108. 

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

Welsch-Pausch, K., McLachlan, M. S. Fate of airborne polychlorinated dibenzo-p-dioxins and dibenzofurans in agricultural ecosystems. Environmental Pollution, 102(1) 129-137 (1998). 

Environmental pollutants such as pesticides and herbicides may be present in fats and oils. In this connection, special attention should also be paid to the presence of polychlorinated biphenyls (PCB) as well as dioxin as well as polycyclic aromatic hydrocarbon in the oil. The presence of high levels of such unwanted matters in the oil may render them unfit for edible purposes. 

The physical properties determined using the ECD are important to different areas of chemistry. Analytical chemistry deals with how much and what are involved in a chemical reaction. Expressed differently, it establishes what we refer to as the QQQ quantitation, qualitative identification, and the quality of the results. The determination of the electron affinities of the chlorinated biphenyls, dioxins, and phenols and the prediction of the response of the ECD and NIMS are important to qualitative and quantitative analyses of environmental pollutants [21]. Polarographic reduction in solutions likewise gives accurate and precise qualitative and quantitative results. The quality of the analyses is expressed by the random and systematic uncertainties in the reported values. These are obtained from the same principle of weighted least squares used to obtain information from ECD data. Wentworth has described the application of the general least-squares procedure to chemical problems [22, 23]. 

The ECD and NIMS are important tools for the analysis of environmental pollutants. The determination of freon levels in the atmosphere and their effects on ozone depletion required the ECD. Identifying the highly toxic chlorinated dioxins was only possible with the ECD and NIMS. Despite these successes very little fundamental data for the reactions of electrons with these molecules in the gas phase have been obtained. This chapter evaluates the available data and presents new data. 

The negative-ion mass spectra for more than 300 environmental pollutants have been reported at two temperatures 373 K and 523 K. The electron affinities of aromatic hydrocarbons, phthalates, chloroethylenes, chlorobenzenes, chloronphtha-lenes, chlorinated biphenyls, and nitrobenzenes have been measured, but the Ea of others, such as the bromobenzenes and chlorinated dioxins, have not. If we know the Ea of the parent compounds, the electron affinities and bond dissociation energies of these compounds can be estimated and compared with the NIMS data. These values are examined using CURES-EC. 

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