Polychlorinated biphenyls activity

It is known that the brain is one of the most sensitive sites of action of steroids in utero, and recently there have been suggestions that EDs may affect normal brain development and behaviour. For example, it has been alleged that in utero exposure to polychlorinated biphenyl compounds (PCBs) resulted in adverse effects on neurologic and intellectual function (memory and attention) in young children born to women who had eaten PCB contaminated fish in the USA." It has also been speculated that exposure to environmental pollutants with steroidal activity may be infinencing human sexual development and sexually controlled behavioiir." ... 

Gellert, R.J. (1978). Uterotrophic activity of polychlorinated biphenyls (PCB) and induction of precocious reproductive aging in neonatally treated female rats. Environmental Research 16, 123-130. 

Kaiser KLE (1974) On the optical activity of polychlorinated biphenyls. Environ Pollut 1 93-101. 

Ohtsubo Y, M Shimura, M Delawary, K Kimbara, M Takagi, T Kudo, AOhta, Y Nagata (2003) Novel approach to the improvement of biphenyl and polychlorinated biphenyl degradation activity promoter implantation by homologous recombination. Appl Environ Microbiol 69 146-153. 

With the recent Increase In activity at hazardous waste sites where cleanup and remedial action are underway, there has emerged a need for rapid analytical methods for assessing contamination in water, sediment, and soil. Of special Interest, because of widespread use and disposal. Is the group of materials known as PCB s (polychlorinated biphenyls). 

Bimetallic nanomaterials such as Pd/Fe, Ni/Fe, and Pd/Au are also active catalysts for the degradation of organic contaminants, including halogenated pesticides, nitroaromatics, polychlorinated biphenyls, and halogenated aliphatics (ethenes and methanes) [151]. 

McKinney, J. D., and L. G. Pederson. 1986. Biological Activity of Polychlorinated Biphenyls (PCBs) Related to Conformational Structure. Biochem. J. 240, 621. 

Colenut and Thorburn [51,52] have also described the procedure using gas stripping of the aqueous sample followed by adsorption onto active carbon from which surface they are taken up in an organic solvent for gas chromatographic analysis. They optimized conditions for the determination of parts per billion of pesticides and polychlorinated biphenyls. 

Quensen, J.F., III, M.A. Mousa, S.A. Boyd, B.J.T. Sanderson, K.L. Froese, and J.P. Giesy. 1998. Reduction of aryl hydrocarbon receptor-mediated activity of polychlorinated biphenyl mixtures due to anaerobic microbial dechlorination. Environ. Toxicol. Chem. 17 806-813. 

Schwartz, T.R. and D.L. Stalling. 1991. Chemometric comparison of polychlorinated biphenyl residues and toxicologically active polychlorinated biphenyl congeners in the eggs of Forster s terns (Sterna forsteri). Arch. Environ. Contam. Toxicol. 20 183-199. 

Smith, L.S., T.R. Schwartz, K. Felz, and T.J. Kubiak. 1990. Determination and occurrence of AHH-active polychlorinated biphenyls, 2,3,7,8-tetrachloro-/>-dioxin and 2,3,7,8-tetrachlorodibenzofuran in Lake Michigan sediment and biota. The question of their relative toxicological significance. Chemosphere 21 1063-1085. 

Storr-Hansen, E. and T. Cederberg. 1992. Determination of coplanar polychlorinated biphenyl (CB) congeners in seal tissues by chromatography on active carbon, dual-column high resolution GC/ECD and high resolution GC/high resolution MS. Chemosphere 24 1181-1196. 

Table II demonstrates the effect of two polychlorinated biphenyl mixtures (Aroclors 1254 and 1242), a polybrominated biphenyl mixture (Firemaster BP6), phenobarbital and -naphtho-flavone on various hemoprotein P-450-mediated monooxygenase activities of rainbow trout hepatic microsomes.

In summary, it would appear that rainbow trout are responsive to cytochrome P -450-type inducers (e.g. planar polychlorinated biphenyls and polycyclic aromatic hydrocarbons), but are not responsive to cytochrome P-450-type inducers (e.g. phenobar-bital and non-planar polychlorinated biphenyls). Although induced rainbow trout hemoprotein(s) P-450 show high activity with cytochrome P -450 substrates, the induced hemoprotein at 57,000 daltons appears, in electrophoretic and spectral properties, to differ from rodent cytochrome P -450. 

The second structural property described by the 4ypc index is the substitution pattern on the benzene ring. The value of the 4ypc index increases sharply with the degree of substitution, while in the isomeric classes of substituted benzenes it increases with the proximity of substituents. Thus, this structural parameter has also been found to be very useful in describing activities and properties of polysubstituted benzenes [103], chlorinated benzenes [279], and polychlorinated biphenyls [286]. 

In activated sludge, 80.6% degraded after a 47-h time period (Pal et al., 1980). Chemical/Physical. Zhang and Rusling (1993) evaluated the bicontinuous microemulsion of surfactant/oil/water as a medium for the dechlorination of polychlorinated biphenyls by electrochemical catalytic reduction. The microemulsion (20 mL) contained didodecyldi-methylammonium bromide, dodecane, and water at 21, 57, and 22 wt %, respectively. The catalyst used was zinc phthalocyanine (2.5 nM). When PCB-1221 (72 mg), the emulsion and catalyst were subjected to a current of mA/cm on 11.2 cm lead electrode for 10 h, a dechlorination yield of 99% was achieved. Reaction products included a monochlorobiphenyl (0.9 mg), biphenyl, and reduced alkylbenzene derivatives. 

Dexter, R.N. and Pavlou, S.P. Mass solubility and aqueotrs activity coefficients of stable organic chenricals in the nrarine environment polychlorinated biphenyls. Mar. Set, 6 41-53, 1978. 

Polychlorinated biphenyls (PCBs) and radioactive substances, predominantly emitted by industrial sources, are not specific to any type of farming activity. As with heavy metals, similar levels of contamination are to be expected in organic and conventional food sources. 

For halogenated aromatic hydrocarbons like polychlorinated biphenyls (PCBs), polychlorinated dibenzofurans (PCDFs), and polychlorinated dibenzo-p-dioxins (PCDDs) the binding to the aryl hydrocarbon (Ah) receptor regulates their toxicity [89]. The Ah receptor controls the induction of one of the cytochrome P450 enzymes in the liver. Toxic responses such as thymic atrophy, iveight loss, immu-notoxicity and acute lethality are associated ivith the relative affinity of PCBs, PCDFs and PCDDs for the Ah receptor [89]. The quantitative structure-activity relationship (QSAR) models predicting the affinity of the halogenated aromatic hydrocarbons ivith the Ah receptor describe the electron acceptor capability as well as the hydrophobicity and polarizability of the chemicals [89[. 

The technology primarily treats clays because their physical and chemical properties, such as external and internal active surfaces produced by their fine crystalline structure, make them difficult to decontaminate. ARC asserts that pilot studies showed that the technology works well on perchloroethylene (PCE), xylene, phenols, and polychlorinated biphenyls (PCBs). 

The Extraksol process can extract organic contaminants such as oils and greases, polynuclear aromatic hydrocarbons (PAHs), pentachlorophenols (PCPs), and phenols from a variety of solid matrices. The Extraksol process can extract polychlorinated biphenyls (PCBs) from clay-bearing soil, sand, and FuUer s earth. Extraksol has successfully treated various media such as activated carbons, refinery sludges, and wood treatment sludges. 

The Waste Management, Inc. (WMX), DeChlor/KGME process involves the ex situ dechlorination of liquid-phase halogenated compounds, particularly polychlorinated biphenyls (PCBs). KGME is the active species in a nucleophilic substitution reaction in which the chlorine atoms are replaced with fragments of the reagent. 

---