Aromatic polybrominated

Bromine can replace sulfonic acid groups on aromatic rings that also contain activating groups. PhenoHc sulfonic acids, for example, are polybrominated (24). 

Except for polybrominated biphenyls (PBB), a limited number of studies regarding the toxicity of aromatic brominated compounds has been performed. Some experiments suggest a moderate acute toxicity of these compounds (ref. 1). 

Among aromatic bromine derivates, only polybrominated biphenyl is known to have a porphyrogenic effect (ref. 24). From scarce data about the toxicity of 4 and 5 porphyrogenic activity in the case of repeated administration could be expected (refs. 25,26). No data are available concerning the remaining compounds. 

Table 1 Concentrations of chlorinated polycyclic aromatic hydrocarbons (CIPAHs), polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), polybrominated biphenyls (PBBs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) in ambient air, soil, and human samples collected from e-waste recycling and reference sites in China... 

BFRs are one of the last classes of halogenated compounds that are still being produced worldwide and used in high quantities in many applications. In order to meet fire safety regulations, flame retardants (FRs) are applied to combustible materials such as polymers, plastics, wood, paper, and textiles. Approximately 25% of all FRs contain bromine as the active ingredient. More than 80 different aliphatic, cyclo-aliphatic, aromatic, and polymeric compounds are used as BFRs. BFRs, such as polybrominated biphenyls (PBBs), polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), and tetrabromobisphenol A (TBBPA), have been used in different consumer products in large quantities, and consequently they were detected in the environment, biota, and even in human samples [26, 27]. 

Andersson O, Blomkvist G. 1981. Polybrominated aromatic pollutants found in fish in Sweden. Chemosphere 10(9) 1051-1060. 

Although the NBS-silica system has useful potential for bromination of electron rich heterocycles, it has limited application to non-acdvated aromatics and sometimes meets problems with polybromination even for the activated heterocycles. Thus, it was of interest to investigate the potential of different brominating agents and different solids. Bromination of anisole with... 

Tetrachlorodibenzo-p-dioxin (TCDD), polychlorinated and polybrominated biphenyls (PCBs and PBBs), benzene, poly aromatic hydrocarbons"... 

Incubation in soils showed that polybrominated biphenyls were resistant to degradation, but were apparently not taken up by plants or leached into groundwater [261]. Commercial formulations of brominated aromatic flame retardants had variable composition some contained highly brominated phenols, but no evidence of contamination with dibenzodioxins and dibenzofurans was found [198]. 

A majority of U.S. biomonitoring efforts measure such analytes as heavy metals, pesticides, cotinine, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), polychlorinated dibenzodioxins, phthalates, and volatile organic compounds (VOCs). Future population-based studies (such as NHANES) will include such chemicals as perfluorinated compounds, polybrominated diphenyl ethers (PBDEs), and perchlorate, on which little exposure information is available. 

Similarly, many xenobiotics, such as pesticides, polynuclear aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), plasticizers, phenols, and some other dmg residues, are also toxic even at trace levels present in the earth s ecosystem [5-7], Without analytical techniques capable of detecting them at nanolevels, we assume the absence of these pollutants in the environment, while these notorious pollutants accumulate in our body tissues resulting in various diseases and side effects such as carcinogenesis and failure of many vital body organs including the kidney, liver, and heart [8-11]. Under such situations, it is essential to have analytical techniques that can detect dmgs, pharmaceuticals, and xenobiotics in biological and environmental samples at very low concentrations. 

Polybrominated biphenyls are solids at room temperature, insoluble in water and soluble to varying degrees in other aromatic hydrocarbons— e.g, benzene and in organic solvents of appropriate (low) polar characteristics. 

The photocatalytic degradation of chlorophenols on ZnO has also been demonstrated [127]. The photocatalytic degradation of other chlorinated aromatic compounds [127], phenol [128-134], fluorinated aromatic compounds [135], and other substituted phenols and aromatic compounds [Izumi 1981, 738 Matthews 1984, 2386 Abdullah 1990, 2099 [136-141] have been demonstrated. The degradation of halogenated aromatic pollutants such as polychlorinated biphenyls (PCBs) [142] and polybrominated dibenzofiirans [143] has also been attempted. 

Furan is not very aromatic and if there is the prospect of forming stable bonds such as C-O single bonds by addition, this may be preferred to substitution. A famous example is the reaction of furan with bromine in methanol. In nonhydroxylic solvents, polybromination occurs as expected, but in MeOH no bromine is added at all ... 

Luijk R, Dorland K, Smit P, Govers HAJ (1993), in Polycyclic aromatic compounds", prediction of the gas chromatographic retention behaviour of polybrominated dibenzo-p-dioxins , p. 565-572, Garrigues Ph, Lamotte M (Eds.), Gordon and Breach, Yverdon Weber R, Hagenmaier H (1994), Organohalogen Compounds 19 7-11. Polyfluorinated diben-zodioxins/furans - Synthesis, analysis and formation", Eds. University of Kyoto, Japan... 

Gevao, B., Al-Omair, A., Sweetman, A., Al-Bahloul, M., Al-Ali, L., Helaleh, M., et al. Passive-sampler derived air concentrations for polybrominated diphenyl ethers and polycyclic aromatic hydrocarbons in Kuwait. Environmental Toxicology and Chemistry, 25(6) 1496-1502 (2006). 

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