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Sample records for polychlorinated terphenyls pcts

  1. Occurrence of polychlorinated terphenyls (PCTs) in indoor particulate matter.

    PubMed Central

    Seidel, U; Schweizer, E; Schweinsberg, F; Wodarz, R; Rettenmeier, A W

    1996-01-01

    In the course of a routine investigation concerned with polychlorinated biphenyl (PCB) contamination of dust collected in classrooms of a junior high school, a group of electron capture detector (ECD)-sensitive compounds with high boiling points were found in addition to PCBs. Using gas chromatographic-mass spectrometric techniques, these compounds were identified as polychlorinated terphenyls (PCTs). Additional measurements indicated that the PCTs were present only in particulate matter collected from the tops of fluorescent light frames but not in air samples obtained concomitantly in the classrooms. Attempts to identify the PCT emission source were unsuccessful. A survey of the literature revealed that PCTs are ubiquitously distributed environmental contaminants, although no data on their indoor occurrence have been reported to date. In view of the toxic effects of PCTs, which seem to be as important as those of PCBs, further attention should be given to the possible presence of PCTs in indoor environments. Images Figure 1. Figure 2. Figure 3. Figure 4. PMID:8959406

  2. Polychlorinated terphenyl patterns and levels in selected marine mammals and a river fish from different continents.

    PubMed

    Rosenfelder, Natalie; Vetter, Walter

    2014-01-01

    Polychlorinated terphenyls (PCTs) are a class of persistent organic pollutants which have been used from the 1920s to the 1980s for similar purposes as polychlorinated biphenyls (PCBs). Comparably little data was available on the PCT distribution in the environment mainly due to analytical difficulties in their determination. By means of a calculation algorithm recently developed we now studied the PCT pattern in individual marine mammal samples and one fish sample from different continents. Altogether, 97 PCTs were detected in eight samples and twelve to 66 tetra- to nonachloroterphenyl (tetra- to nonaCT) congeners were detected in individual samples. PCTs were present in all marine mammal samples which originated from four continents, but the PCT pattern was varied. TetraCTs were dominant in the sample from Africa, Australia, Spitsbergen (European Arctic) and in a sample from the Baltic Sea, heptaCTs in samples from the North Sea and octaCTs in a sample from Iceland. The abundance of sumPCTs relative to PCB 153, estimated from the GC/ECNI-MS response corrected for the degree of chlorination, ranged from 0.9 to 8.8%, corresponding with ~0.22-2.2% of the total PCB content. The highest PCT level detected was 980 mg/kg lipid in a harbour seal from the North Sea, Germany. The results from this study indicated that samples from certain areas, e.g. the North Sea may still be polluted with PCTs. PMID:24211498

  3. Sources and Distribution of Polychlorinated Terphenyls at a Major US Aeronautics Research Facility.

    PubMed

    HALE; ENOS; GALLAGHER

    1998-11-01

    / High concentrations of an unusual, complex mixture of chlorinated compounds were discovered in sediments and oysters near a federal aeronautics facility during implementation of a pollutant screening protocol. The mixture was identified as Aroclor 5432, a polychlorinated terphenyl (PCT) formulation, produced in the US until 1972. PCTs, particularly low chlorinated mixtures, have rarely been reported in the environment, despite significant manufacture and usage. Releases were traced to two outfalls. Creek sediments downstream of one contained concentrations as high as 200,000 |gmg/kg (dry weight basis); those in indigenous oysters reached 35,000 |gmg/kg, indicating significant bioavailability and bioaccumulation potential. Subsequent work showed that PCTs were widely disseminated in marsh grass, crabs, and fish. PCTs, PCBs, and mercury were also detected in storm drain lines entering these outfalls. The lines received input from both storm water and research buildings. Historical hydraulic fluid leaks and in-service compressor fluids in some buildings contained PCTs and PCBs. Contaminated materials on-site were removed to minimize pollutant spread. Aroclor 5432 usage, most likely as compressor/hydraulic fluid additives, probably ended about ten years prior to its on-site detection. In terms of biological effects, intraperitoneal injection of fish with Aroclor 5432 induced cytochrome P-4501A (CYP1A) and ethoxyresorufin O-deethylase (EROD) activity to a similar degree as PCB Aroclor 1254 and to a greater extent than PCT Aroclor 5460. The presence of high concentrations of PCTs contributed to the facility being included on the National Priorities List. It subsequently became the first US federal facility to sign a Federal Facility Agreement, identifying cleanup responsibilities, prior to formal listing.KEY WORDS: Polychlorinated terphenyls; Aroclor; Contaminated sediments; Hydraulic fluid; Enzyme induction; Polychlorinated biphenyls PMID:9732522

  4. Sources and distribution of polychlorinated terphenyls at a major US aeronautics research facility

    SciTech Connect

    Hale, R.C.; Enos, C.; Gallagher, K.

    1998-11-01

    High concentrations of an unusual, complex mixture of chlorinated compounds were discovered in sediments and oysters near a federal aeronautics facility during implementation of a pollutant screening protocol. The mixture was identified as Aroclor 5432, a polychlorinated terphenyl (PCT) formulation, produced in the US until 1972. PCTs, particularly low chlorinated mixtures, have rarely been reported in the environment, despite significant manufacture and usage. PCBs, and mercury were also detected in storm drain lines entering these outfalls. The lines received input from both storm water and research buildings. Historical hydraulic fluid leaks and in-service compressor fluids in some buildings contained PCTs and PCBs. Contaminated materials on-site were removed to minimize pollutant spread. Aroclor 5432 usage, most likely as compressor/hydraulic fluid additives, probably ended about ten years prior to its on-site detection, in terms of biological effects, intraperitoneal injection of fish with Aroclor 5432 induced cytochrome P-4501A (CYP1A) and ethoxyresorufin O-deethylase (EROD) activity to a similar degree as PCB Aroclor 1254 and to a greater extent than PCT Aroclor 5460. The presence of high concentrations of PCTs contributed to the facility being included on the National Priorities List. It subsequently became the first US federal facility to sign a Federal Facility Agreement, identifying cleanup responsibilities, prior to formal listing.

  5. 40 CFR 704.45 - Chlorinated terphenyl.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... means the percent by weight of chlorine for each isomer (ortho, meta, and para). (3) Isomeric ratio... chlorinated terphenyl. (4) A description of the isomeric ratio and extent of chlorination of the...

  6. Structural and mechanistic basis behind the inhibitory interaction of PcTS on α-synuclein amyloid fibril formation

    PubMed Central

    Lamberto, Gonzalo R.; Binolfi, Andrés; Orcellet, María L.; Bertoncini, Carlos W.; Zweckstetter, Markus; Griesinger, Christian; Fernández, Claudio O.

    2009-01-01

    The identification of aggregation inhibitors and the investigation of their mechanism of action are fundamental in the quest to mitigate the pathological consequences of amyloid formation. Here, characterization of the structural and mechanistic basis for the antiamyloidogenic effect of phthalocyanine tetrasulfonate (PcTS) on α-synuclein (AS) allowed us to demonstrate that specific aromatic interactions are central for ligand-mediated inhibition of amyloid formation. We provide evidence indicating that the mechanism behind the antiamyloidogenic effect of PcTS is correlated with the trapping of prefibrillar AS species during the early stages of the assembly process. By using NMR spectroscopy, we have located the primary binding region for PcTS to a specific site in the N terminus of AS, involving the amino acid Tyr-39 as the anchoring residue. Moreover, the residue-specific structural characterization of the AS-PcTS complex provided the basis for the rational design of nonamyloidogenic species of AS, highlighting the role of aromatic interactions in driving AS amyloid assembly. A comparative analysis with other proteins involved in neurodegenerative disorders reveals that aromatic recognition interfaces might constitute a key structural element to target their aggregation pathways. These findings emphasize the use of aggregation inhibitors as molecular probes to assess structural and toxic mechanisms related to amyloid formation and the potential of small molecules as therapeutics for amyloid-related pathologies. PMID:19948969

  7. Polychlorinated Biphenyls

    ERIC Educational Resources Information Center

    Peakall, David B.; Lincer, Jeffrey L.

    1970-01-01

    Describes structure, use, analysis, and toxicological properties of polychlorinated biphenyls. Provides data on occurrence and biological magnification in ecosystems. Significance, and synergistic relationships with DDT summarized. (AL)

  8. Electrical and optical properties of m-terphenyl thin films

    NASA Astrophysics Data System (ADS)

    Tkaczyk, S. W.

    2001-04-01

    In this work the results of m-terphenyl polycrystalline thin films investigations are presented. The main purpose of the investigations was to determine the mechanism of DC conductivity in the disordered m-terphenyl polycrystalline structures. The measurements were carried out for the thin films of m-terphenyl of the thickness varied from 2 to 13 micrometers with the presence of an external electrical field, which strength varied from 0 to 106 V/cm. Applied temperature range was 15-325K. The investigated m-terphenyl thin films were supplied with either the gold and Aluminum or the gold and carbon electrodes. The determined values of activation energy were found to be in the range of kT to 0.2 eV. The study let us determine the influence of an external electric field on the height of the potential barriers between the trapped charge carriers. The results obtained as well as their analysis drive to a conclusion that an injection of an electric charge from the electrodes into the investigated material's bulk takes place through the thermoemission and field emission processes.

  9. Electrical conductivity of the polycrystalline films of p-terphenyl

    NASA Astrophysics Data System (ADS)

    Tkaczyk, S. W.

    1999-04-01

    Some results of p-terphenyl thin films investigations are presented. The mechanism of DC conductivity within unordered polycrystalline structures of p-terphenyl was investigated. The measurements were carried out for p-terphenyl films' thickness varying from 2 micrometers up to 15 micrometers . During the experiment the polarization voltage and temperature were changed from 0 to 200 V and 15 to 325 K, respectively. The p-terphenyl films were supplied with gold and aluminum electrodes. The obtained results and their analysis indicate that the injection of charge from the electrodes into the area of the investigated material proceeds by field- and thermoemission. The charge transport through the material's bulk is controlled by traps (hopping mechanism and Poole- Frenkel phenomenon). The determined values of the activation energy are in the range of kT (for the hopping area at low temperatures) through 0.06 eV in the range of 100 - 200 K to about 0.6 eV in the metallic conductivity area (220 - 320 K).

  10. In vitro antileishmanial activity of trans-stilbene and terphenyl compounds.

    PubMed

    Castelli, Germano; Bruno, Federica; Vitale, Fabrizio; Roberti, Marinella; Colomba, Claudia; Giacomini, Elisa; Guidotti, Laura; Cascio, Antonio; Tolomeo, Manlio

    2016-07-01

    Leishmaniasis are globally widespread parasitic diseases which often leads to death if left untreated. Currently available drugs present different drawbacks, so there is an urgent need to develop new, safe and cost-effective drugs against leishmaniasis. In this study we tested a small library of trans-stilbene and terphenyl derivatives against promastigote, amastigotes and intramacrophage amastigote forms of Leishmania infantum. Two compounds of the series, the trans-stilbene 3 and the terphenyl 11, presented the best activity and safety profiles. Terphenyl 11 showed a leshmanicidal activity higher than pentostam and the ability to induce apoptosis selectively in Leishmania infantum while saving macrophages and primary epithelial cells. Our data indicate that terphenyl compounds, as well as stilbenes, are endowed with leishmanicidal activity, showing potential for further studies in the context of leishmanial therapy. PMID:26953250

  11. Luminescence of benzoic acid polycrystals doped with n-terphenyl and n-quaterphenyl

    SciTech Connect

    Zarochentseva, E.P.; Korotkov, V.I.; Oleinik, Y.P.

    1994-10-01

    The luminescence and luminescence excitation spectra of benzoic acid polycrystals, terphenyl, quaterphenyl, and benzoic acid doped with terphenyl and quaterphenyl are studied. Blue shifts of the fluorescence and fluorscence excitation spectra are found. These shifts result from nonplanar entering of polyphenyl molecules into the unit cell of the benzoic acid dimmers around the acid carbonyl groups. In the impurity polycrystals at room temperature, the internal conversion from the triplet level efficiently occurs resulting in the absence of phosphorescence. 12 refs., 4 figs.

  12. Synthesis and Photophysical Properties of Biphenyl and Terphenyl Arylene–Ethynylene Macrocycles

    PubMed Central

    2015-01-01

    A series of single-walled carbon nanotube precursors, C3h-symmetric cyclotri(ethynylene)(biphenyl-2,4′-diyl) and cyclotri(ethynylene)(p-terphenyl-2,4″-diyl), have been prepared by a linear stepwise oligomerization–cyclization route and by statistical intermolecular cyclooligomerization. In addition to producing these members of a novel class of arylene ethynylene macrocycles, 1 and 2, the latter statistical process produces the smaller cyclic dimer, cyclodi(ethynylene)(p-terphenyl-2,4″-diyl) and the larger cyclic tetramer cyclotetra(ethynylene)(biphenyl-2,4′-diyl). These macrocycles display large Stokes shifts in their fluorescence spectra. Their biphenyl or terphenyl connectivity prevents these macrocycles from achieving full planarity in the ground state, and the ethynylene moieties could provide synthetic access to cyclic arylene oligomers and discrete carbon nanotube segments. PMID:24506215

  13. Multistep Synthesis of a Terphenyl Derivative Showcasing the Diels-Alder Reaction

    ERIC Educational Resources Information Center

    Davie, Elizabeth A. Colby

    2015-01-01

    An adaptable multistep synthesis project designed for the culmination of a second-year organic chemistry laboratory course is described. The target compound is a terphenyl derivative that is an intermediate in the synthesis of compounds used in organic light-emitting devices. Students react a conjugated diene with dimethylacetylene dicarboxylate…

  14. Binding of polychlorinated biphenyls to the aryl hydrocarbon receptor.

    PubMed Central

    Kafafi, S A; Afeefy, H Y; Ali, A H; Said, H K; Kafafi, A G

    1993-01-01

    A new thermodynamic model for calculating the dissociation constants of complexes formed between the aryl hydrocarbon receptor (AhR) and polychlorinated biphenyls (PCBs) is reported. The free energies of binding of PCBs to AhR are controlled by their lipophilicities, electron affinities, and entropies. The corresponding physicochemical properties of polychlorinated dibenzo-p-dioxins and dibenzofurans also control their interactions with AhR. We present evidence supporting the hypothesis that the majority of PCBs are likely to interact with AhR in their nonplanar conformations. In addition, we demonstrate that the affinities of PCBs for AhR relative to 2,3,7,8-tetrachlorodibenzo-p-dioxin correlate with corresponding toxic equivalency factors in animals. The reported methodology is likely to be applicable to other polyhalogenated and mixed polyhalogenated bi- and terphenyls and related xenobiotics; thus, it could minimize the number of in vivo studies in laboratory animals and facilitate the identification of potentially hazardous aromatic xenobiotics. Images p422-a Figure 2. PMID:8119253

  15. Properties of single crystal para-terphenyl as medium for high resolution TOF detector

    NASA Astrophysics Data System (ADS)

    De Gerone, M.; Biasotti, M.; Ceriale, V.; Corsini, D.; Gatti, F.; Orlando, A.; Pizzigoni, G.

    2016-07-01

    In the last years organic scintillators have been largely investigated in order to achieve high light yield together with good time response. Pure organic compound with high quality crystalline structure can achieve both this goals. Among a large type of organic compound, para-terphenyl (C18H14) have proven to have practical applications as detector medium for particle physics. In this work, the characterization of different sizes high quality mono-crystal p-terphenyl samples is presented. The optical and scintillation properties (emission spectrum, light yield, attenuation length, and decay time) are investigated. Coupling a Silicon PhotoMultiplier-based readout system to the crystal, a small prototype for a high resolution TOF detector was built; the preliminary results, obtained on a 20×30×3 mm3 sample, with dual-side read-out (Hamamatsu S10931-050P SiPMs) and irradiated with 90Sr source, show a time resolution of 35 ps.

  16. Synthesis, biological evaluation and modeling studies of terphenyl topoisomerase IIα inhibitors as anticancer agents.

    PubMed

    Qiu, Jin; Zhao, Baobing; Zhong, Wanxia; Shen, Yuemao; Lin, Houwen

    2015-04-13

    We report the synthesis and evaluation of a series of novel terphenyls. Compound 17 had the most potent anticancer activity, indicating that the phenolic hydroxyl was a key group. A DNA relaxation test showed that compound 17 had a strong inhibitory effect on TOP2α, but not on TOP1, which was consistent with the docking analysis results. We performed a 3D-QSAR study using CoMFA and CoMSIA to determine, for the first time, the chemical-biological relationship in the inhibition of TOP by terphenyls. The CoMFA and CoMSIA model had good modeling statistics: leave-one-out q(2) of 0.605 and 0.622, r(2) of 0.998 and 0.994, and r(2)pred (test set) of 0.742 and 0.660. These results suggest that the ortho-phenolic hydroxyl on ring A is important for producing terphenyls with more efficacious activity. PMID:25800514

  17. Low-Coordinate First Row Early Transition Metal Complexes Stabilized by Modified Terphenyl Ligands

    NASA Astrophysics Data System (ADS)

    Boynton, Jessica Nicole

    The research in this dissertation is focused on the synthesis, structural, and magnetic characterization of two-coordinate open shell (d1-d4) transition metal complexes. Background information on this field of endeavor is provided in Chapter 1. In Chapter 2 I describe the synthesis and characterization of the mononuclear chromium (II) terphenyl substituted primary amido complexes and a Lewis base adduct. These studies suggest that the two-coordinate chromium complexes have significant spin-orbit coupling effects which lead to moments lower than the spin only value of 4.90 muB owing to the fact that lambda (the spin orbit coupling parameter) is positive. The three-coordinated complex 2.3 had a magnetic moment of 3.77 muB. The synthesis and characterization of the first stable two-coordinate vanadium complexes are described in Chapter 3. The values suggest a significant spin orbital angular momentum contribution that leads to a magnetic moment that is lower than their spin only value of 3.87 muB. DFT calculations showed that the major absorptions in their UV-Vis spectra were due to ligand to metal charge transfer transitions. The titanium synthesis and characterization of the bisamido complex along with its three-coordinate titanium(III) precursor are described in Chapter 4. Compound 4.1 was obtained via the stoichiometric reaction of LiN(H)AriPr 6 with the Ti(III) complex TiCl3 *2NMe 3 in trimethylamine. The precursor 4.1 has trigonal pyramidal coordination at the titanium atom, with bonding to two amido nitrogens and a chlorine as well as a secondary interaction to a flanking aryl ring of a terphenyl substituent. Compound 4.2 displays a very distorted four-coordinate metal environment in which the titanium atom is bound to two amido nitrogens and to two carbons from a terphenyl aryl ring. This structure is in sharp contrast to the two-coordinate linear structure that was observed in its first row metal (V-Ni) analogs. The synthesis and characterization of

  18. Polychlorinated biphenyls (PCBs)

    Integrated Risk Information System (IRIS)

    Polychlorinated biphenyls ( PCBs ) ; CASRN 1336 - 36 - 3 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments f

  19. Four-wave mixing spectroscopy of molecular dimers. Application to dimers of pentacene in p-terphenyl

    NASA Astrophysics Data System (ADS)

    Levinsky, Howard; Wiersma, Douwe A.

    1982-10-01

    Dispersive coherent Stokes-Raman scattering (CSRS) experiments on pentacene dimers in p-terphenyl were performed to locate the corresponding singly excited, delocalized, dimer levels. In addition the CNRS technique was used to locate the doubly excited dimer state. Future experiments exploring the dynamics of this novel state are discussed.

  20. Rickenyls A-E, antioxidative terphenyls from the fungus Hypoxylon rickii (Xylariaceae, Ascomycota).

    PubMed

    Kuhnert, Eric; Surup, Frank; Herrmann, Jennifer; Huch, Volker; Müller, Rolf; Stadler, Marc

    2015-10-01

    Our screening efforts for new natural products with interesting bioactivity have revealed the neotropical ascomycete Hypoxylon rickii as a prolific source. We isolated five secondary metabolites with a p-terphenyl backbone from the mycelial extract of a fermentation of this fungus in 70 l scale by using RP-HPLC, which were named rickenyls A-E (1-5). Their structures were elucidated by X-ray crystallography and NMR spectroscopy, complemented by HRESIMS. Two of the compounds contained a quinone core structure in ortho (2) and para-position (5), respectively. We obtained 2 spontaneously and by lead tetraacetate oxidation from 1. All compounds were screened for antimicrobial, antioxidative and cytotoxic activities. Rickenyl A (1) exhibited strong antioxidative effects and moderate cytotoxic activity against various cancer cell lines. PMID:26296745

  1. Solidification of acoustically levitated o-terphenyl crystals: a Raman study

    NASA Astrophysics Data System (ADS)

    Biswas, A.

    1995-01-01

    Ultrasonic levitation of millimeter size o-terphenyl (OTP) crystals was carried out in a variable temperature enclosure. Levitated crystals were melted (MP = 331 K), undercooled and then seeded in order to initiate solidification. The incidence of an oargon laser beam on the sample, during containerless processing, allowed elastic and low frequency (< 200 cm -1) shifted inelastic Raman scattering to be monitored. The Raman spectra undergo remarkable changes during thermal processing, enabling the tracking of inter-molecular structural reconfigurations occurring in the solid and liquid states. Furthermore, the Raman scattered light proved to be a reliable tool for monitoring the kinetics of phase transformation. Thus tracking the peak intensity of a Raman feature allowed a measure of volume fraction transformation rates, during solidification initiated at different undercooling levels. Growth rates as a function of undercooling were inferred from these measurements and are compared to existing models.

  2. Density scaling and decoupling in o-terphenyl, salol, and dibutyphthalate

    NASA Astrophysics Data System (ADS)

    Casalini, R.; Bair, S. S.; Roland, C. M.

    2016-08-01

    We present new viscosity and equation of state (EoS) results extending to high pressures for o-terphenyl, salol, and dibutylphthalate. Using these and data from the literature, we show that the three liquids all conform to density scaling; that is, their reduced viscosities and reorientational relaxation times are a function of the ratio of temperature and density with the latter raised to a constant. Moreover, the functional form of the dependence on this ratio is independent of the experimental probe of the dynamics. This means that there is no decoupling of the viscosities and relaxation times over the measured range of conditions. Previous literature at odds with these results was based on erroneous extrapolations of the EoS or problematic diamond anvil viscosity data. Thus, there are no exceptions to the experimental fact that every non-associated liquid complies with density scaling with an invariant scaling exponent.

  3. Dynamics of a molecular glass former: Energy landscapes for diffusion in ortho-terphenyl

    NASA Astrophysics Data System (ADS)

    Niblett, S. P.; de Souza, V. K.; Stevenson, J. D.; Wales, D. J.

    2016-07-01

    Relaxation times and transport processes of many glass-forming supercooled liquids exhibit a super-Arrhenius temperature dependence. We examine this phenomenon by computer simulation of the Lewis-Wahnström model for ortho-terphenyl. We propose a microscopic definition for a single-molecule cage-breaking transition and show that, when correlation behaviour is taken into account, these rearrangements are sufficient to reproduce the correct translational diffusion constants over an intermediate temperature range in the supercooled regime. We show that super-Arrhenius behaviour can be attributed to increasing negative correlation in particle movement at lower temperatures and relate this to the cage-breaking description. Finally, we sample the potential energy landscape of the model and show that it displays hierarchical ordering. Substructures in the landscape, which may correspond to metabasins, have boundaries defined by cage-breaking transitions. The cage-breaking formulation provides a direct link between the potential energy landscape and macroscopic diffusion behaviour.

  4. Synthesis of a hybrid m-terphenyl/o-carborane building block: applications in phosphine ligand design.

    PubMed

    Lugo, Christopher A; Moore, Curtis E; Rheingold, Arnold L; Lavallo, Vincent

    2015-03-01

    A hybrid terphenyl/o-carborane ligand building block is synthesized by the reaction of m-terphenylalkyne with B10H14. This sterically demanding substituent can be installed into ligands, as demonstrated by the preparation of carboranylphosphine. The bulky phosphine reacts with [ClRh(CO)2]2 to produce monophosphine complex ClRhL(CO)2, which subsequently extrudes CO under vacuum to afford the dimeric species [ClRhL(CO)]2. The latter complex does not react with excess phosphine and is resistant toward cyclometalation, which is in contrast to related o-carborane phosphine complexes. Data from a single-crystal X-ray diffraction study are utilized to quantify the steric impact of the ligand via the percent buried volume approach. PMID:25668570

  5. Nanocalorimetry of vapor-deposited organic glasses: tris-naphthylbenzene, decalin and ortho-terphenyl

    NASA Astrophysics Data System (ADS)

    Whitaker, Katherine R.

    Physical vapor deposition can be used to prepare glasses with extraordinary properties. By optimizing the substrate temperature and deposition rate, glasses with low enthalpy, high density and high kinetic stability, as compared to the ordinary liquid-cooled glass, can be produced. The heat capacity of 'stable glasses' has been measured with conventional calorimetry, but such techniques are limited to bulk samples; the properties of more technologically relevant thin films cannot be measured. In this thesis, nanocalorimetry was utilized to measure the heat capacity of thin films of four organic glassformers: alpha,alpha,beta-tris-naphthylbenzene (alphaalphabeta-TNB),cis- and trans-decahydronaphthalene (cis- and trans -decalin) and o-terphenyl. A number of new and important results came out of the AC nanocalorimetry experiments on these molecules. alphaalphabeta-TNB thin films showed thickness dependent transformation times for films up to one micron in thickness, consistent with the work on indomethacin. This result suggested that highly suppressed bulk transformation rates are a general feature associated with the kinetics of stable glass transformation. One way glassformers can be characterized is by their fragility, or their temperature dependent behavior as Tg is approached. Decalin, the molecular glassformer with the highest reported fragility, was shown to be capable of forming stable glasses when vapor-deposited. This result implies that surface mobility, which is deemed the controlling mechanism for stable glass formation, is also present in high fragility systems. Experiments on a variety of cis/trans-decalin mixture compositions showed that vapor deposition can also be used to make stable glasses of mixtures. The ability of an array of compositions to form stable glasses is a strong argument against nanocrystals being responsible for the extraordinary properties of stable glasses. Finally, in situ experiments on o-terphenyl were able to span the range of

  6. Synthesis of meta-Terphenyl-2,2''-diols by Anodic C-C Cross-Coupling Reactions.

    PubMed

    Lips, Sebastian; Wiebe, Anton; Elsler, Bernd; Schollmeyer, Dieter; Dyballa, Katrin M; Franke, Robert; Waldvogel, Siegfried R

    2016-08-26

    The anodic C-C cross-coupling reaction is a versatile synthetic approach to symmetric and non-symmetric biphenols and arylated phenols. We herein present a metal-free electrosynthetic method that provides access to symmetric and non-symmetric meta-terphenyl-2,2''-diols in good yields and high selectivity. Symmetric derivatives can be obtained by direct electrolysis in an undivided cell. The synthesis of non-symmetric meta-terphenyl-2,2''-diols required two electrochemical steps. The reactions are easy to conduct and scalable. The method also features a broad substrate scope, and a large variety of functional groups are tolerated. The target molecules may serve as [OCO](3-) pincer ligands. PMID:27490451

  7. Structural, optical and dynamical properties of a high birefringence laterally fluorinated terphenyl isothiocyanate

    NASA Astrophysics Data System (ADS)

    Sinha, D.; Mandal, P. K.; Dabrowski, R.

    2015-02-01

    A doubly fluorinated isothiocyanato butyl terphenyl compound exhibiting a broad range of the nematic and a narrow range of smectic phase has been investigated by X-ray, dielectric and optical methods and compared with the properties of singly and doubly fluorinated ethyl homologues to see the effect of fluorination and chain flexibility. Contrary to common perception, weak antiparallel correlation of molecules is observed in each compound both from X-ray and dielectric studies. Observed dielectric anisotropy is strong enough to ensure a driving voltage suitable for thin film transistor-based liquid crystal display. Measured splay elastic constant suggests that the present compound will exhibit the fastest response. Flip-flop mode relaxations are observed in a few hundred kHz to MHz range. All the compounds exhibit high birefringence (0.373-0.331). They also show high order parameters at low temperatures. These compounds are expected to be suitable for formulating high birefringence nematic mixtures for fast switching displays.

  8. Improving UV-glass PMTs with a p-Terphenyl Wavelength Shifter

    NASA Astrophysics Data System (ADS)

    Joosten, Sylvester; Meziani, Zein-Eddine; Kaczanowicz, Ed; Rehfuss, Melanie; Duran, Burcu; Paolone, Michael

    2015-10-01

    UV-glass PMTs are often the limiting factor in a Cherenkov detector, due to their poor quantum efficiency (QE) below 300nm due to the UV-glass transparency. The application of a p-Terphenyl wavelength shifter to the face of these PMTs dramatically improves the QE for short wavelengths, rivaling that of a much more expensive quartz PMT. This is especially interesting in the context of multi-anode (MA) PMTs, which are supremely suited for application in future open-environment Cherenkov detectors at very high luminosities due to their small size, lower sensitivity to magnetic fields, and high potential for advanced background rejection. This will become critical at Jefferson Lab entering the 12 GeV era, as well as for a future electron-ion collider. We will discuss the process of coating the PMTs through vacuum evaporation, and the performance testing taking place at Temple University for these multi-anode PMTs, as well as the results obtained with the more traditional 5-inch PMTs that were coated for the low-threshold Cherenkov counter (LTCC) of the CLAS12 spectrometer at Jefferson Lab.

  9. Performance of UV-glass MaPMT with p-Terphenyl Wavelength Shifter

    NASA Astrophysics Data System (ADS)

    Rehfuss, Melanie; Joosten, Sylvester; Meziani, Zein-Eddine; Kaczanowicz, Edward

    2016-03-01

    UV-glass PMTs are often the limiting factor in a Cherenkov detector because of their poor quantum efficiency (QE) below 300nm due to the UV-glass transparency. The application of a p-Terphenyl wavelength shifter to the face of these PMTs dramatically improves the QE for short wavelengths, rivaling that of a much more expensive quartz PMT. This is especially interesting in the context of multi-anode (Ma) PMTs, which are supremely suited for application in future open-environment Cherenkov detectors at very high luminosities due to their small size, lower sensitivity to magnetic fields, and high potential for advanced background rejection due to their pixelization. This will become critical at Jefferson Lab entering the 12 GeV era, as well as for a future electron-ion collider both providing a high luminosity. We will discuss the process of coating the PMTs through vacuum evaporation, and the performance testing taking place at Temple University for Hamamatsu model H12700A-03 multi-anode PMTs as well the background rejection schemes that will be devised using these MaPMTs.

  10. Structural Control of Nonadiabatic Photochemical Bond Formation: Photocyclization in Structurally Modified ortho-Terphenyls.

    PubMed

    Molloy, Molly S; Snyder, Joshua A; DeFrancisco, Justin R; Bragg, Arthur E

    2016-06-16

    Understanding how molecular structure impacts the shapes of potential energy surfaces and prospects for nonadiabatic photochemical dynamics is critical for predicting and controlling the chemistry of molecular excited states. Ultrafast transient absorption spectroscopy was used to interrogate photoinduced, nonadiabatic 6π cyclization of a collection of ortho-terphenyls (OTP) modified with alkyl substituents of different sizes and electron-donating/withdrawing character positioned on its central and pendant phenyl rings. OTP alkylated at the 4,4″ and 4',5' positions of the pendant and central rings, respectively, exhibiting biphasic excited-state relaxation; this is qualitatively similar to relaxation of OTP itself, including a fast decrease in excited-state absorption (τ1 = 1-4 ps) followed by formation of metastable cyclized photoproducts (τ2 = 3-47 ps) that share common characteristic spectroscopic features for all substitutions despite variations in chemical nature of the substituents. By contrast, anomalous excited-state dynamics are observed for 3',6'dimethyl-OTP, in which the methyl substituents crowd the pendant rings sterically; time-resolved spectral dynamics and low photochemical reactivity with iodine reveal that methylation proximal to the pendant rings impedes nonadiabatic cyclization. Results from transient measurements and quantum-chemical calculations are used to decipher the nature of excited state relaxation mechanisms in these systems and how they are perturbed by mechanical, electronic, and steric interactions induced by substituents. PMID:27171560

  11. Solvent-Free Dynamic Nuclear Polarization of Amorphous and Crystalline ortho-Terphenyl

    PubMed Central

    Ong, Ta-Chung; Mak-Jurkauskas, Melody L.; Walish, Joseph J.; Michaelis, Vladimir K.; Corzilius, Björn; Smith, Albert A.; Clausen, Andrew M.; Cheetham, Janet C.; Swager, Timothy M.; Griffin, Robert G.

    2014-01-01

    Dynamic nuclear polarization (DNP) of amorphous and crystalline ortho-terphenyl (OTP) in the absence of glass forming agents is presented in order to gauge the feasibility of applying DNP to pharmaceutical solid-state nuclear magnetic resonance experiments and to study the effect of intermolecular structure, or lack thereof, on the DNP enhancement. By way of 1H–13C cross-polarization, we obtained a DNP enhancement (ε) of 58 for 95% deuterated OTP in the amorphous state using the biradical bis-TEMPO terephthalate (bTtereph) and ε of 36 in the crystalline state. Measurements of the 1H T1 and electron paramagnetic resonance experiments showed the crystallization process led to phase separation of the polarization agent, creating an inhomogeneous distribution of radicals within the sample. Consequently, the effective radical concentration was decreased in the bulk OTP phase, and long-range 1H–1H spin diffusion was the main polarization propagation mechanism. Preliminary DNP experiments with the glass-forming anti-inflammation drug, indomethacin, showed promising results, and further studies are underway to prepare DNP samples using pharmaceutical techniques. PMID:23421391

  12. Fast Crystal Growth in o-Terphenyl Glasses: A Possible Role for Fracture and Surface Mobility.

    PubMed

    Powell, C Travis; Xi, Hanmi; Sun, Ye; Gunn, Erica; Chen, Yinshan; Ediger, M D; Yu, Lian

    2015-08-01

    Molecular liquids can develop a fast mode of crystal growth ("GC growth") near the glass transition temperature. This phenomenon remains imperfectly understood with several explanations proposed. We report that GC growth in o-terphenyl conserves the overall volume, despite a 5% higher density of the crystal, and produces fine crystal grains with the same unit cell as normally grown crystals. These results indicate that GC growth continuously creates voids and free surfaces, possibly by fracture. This aspect of the phenomenon has not been considered by previous treatments and is a difficulty for those models that hypothesize a 5% strain without voids. Given the existence of even faster crystal growth on the free surface of molecular glasses, we consider the possibility that GC growth is facilitated by fracture and surface mobility. This notion has support from the fact that GC growth and surface growth are both highly correlated with surface diffusivity and with fast crystal growth along preformed cracks in the glass. PMID:26161577

  13. POLYCHLORINATED BIPHENYLS: PROGRESS AND PROBLEMS

    EPA Science Inventory

    Polychlorinated biphenyls (PCBs) are industrial chemical products which are synthesized by the direct chlorination of biphenyl. he degree of biphenyl ring chlorination determines the physical properties and applications of commercial PCBs and, therefore, it is not surprising that...

  14. Rotational relaxation in ortho-terphenyl: using atomistic simulations to bridge theory and experiment.

    PubMed

    Eastwood, Michael P; Chitra, Tarun; Jumper, John M; Palmo, Kim; Pan, Albert C; Shaw, David E

    2013-10-24

    Understanding the nature of the glass transition--the dramatic slowing of dynamics and eventual emergence of a disordered solid from a cooling liquid--is a fundamental challenge in physical science. A central characteristic of glass-forming liquids is a non-exponential main relaxation process. The extent of deviation from exponential relaxation typically becomes more pronounced on cooling. Theories that predict a growth of spatially heterogeneous dynamics as temperature is lowered can explain these observations. In apparent contradiction to these theories, however, some experiments suggest that certain substances--notably including the intensely studied molecular glass-former ortho-terphenyl (OTP)--have a main relaxation process whose shape is essentially temperature independent, even though other observables predicted to be correlated with the degree of dynamical heterogeneity are temperature dependent. Here we report the first simulations based on an atomistic model of OTP that reach equilibrium at temperatures well into the supercooled regime. We first show that the results of these simulations are in reasonable quantitative agreement with experimental data for several basic properties over a wide range of temperatures. We then focus on rotational relaxation, finding nearly exponential behavior at high temperatures with clearly increasing deviations as temperature is lowered. The much weaker temperature dependence observed in light-scattering experiments also emerges from the same simulation data when we calculate correlation functions similar to those probed experimentally; this highlights the diversity of temperature dependencies that can be obtained with different probes. Further analysis suggests that the temperature insensitivity observed in the light-scattering experiments stems from the dependence of these measurements on internal as well as rotational molecular motion. Within the temperature range of our OTP simulations, our results strongly suggest that

  15. Carcinogenic effects of polychlorinated biphenyls.

    PubMed

    Faroon, O M; Keith, S; Jones, D; De Rosa, C

    2001-03-01

    As part of its mandate, the Agency for Toxic Substances and Disease Registry (ATSDR) prepares toxicological profiles on hazardous chemicals found at Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) National Priorities List (NPL) sites that have the greatest public health impact. These profiles comprehensively summarize toxicological and environmental information. This article constitutes the release of an important section of the Toxicological profile for polychlorinated biphenyls [ATSDR. 2000: Toxicological profile for polychlorinated biphenyls. Atlanta, GA: US Department of Health and Human Services, Agency for Toxic Substances and Disease Registry.] into the scientific literature. This article focuses on the carcinogenic effects of this group of synthetic organic chemicals (polychlorinated biphenyls) in humans and animals. Information on other health effects, toxicokinetics, mechanisms of toxicity, biomarkers, interactions, chemical and physical properties, potential for human exposure, and regulations and advisories is detailed in the profile. PMID:12117297

  16. CHARACTERIZATION OF PCB (POLYCHLORINATED BIPHENYL) TRANSFORMER/CAPACITOR FLUIDS AND CORRELATION WITH PCDDS (POLYCHLORINATED DIBENZO-P-DIOXINS) AND PCDFS (POLYCHLORINATED DIBENZOFURANS) IN SOOT

    EPA Science Inventory

    Dielectric fluids in transformers and capacitors often contain polychlorinated biphenyls (PCBs) or chlorobenzenes. These substances may generate polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzo-p-dioxins (PCDDs) under certain conditions of combustion/pyrolysis. W...

  17. Nonoccupational exposure to polychlorinated biphenyls

    SciTech Connect

    Thurston, F.E.

    1988-01-01

    Polychlorinated biphenyls became worldwide environmental contaminants during five decades of industrial use. They cause cancer in some animals and are suspected of causing birth defects and elevated triglycerides in humans. The risk to humans from low-level exposure is unclear. No clinical symptoms have yet been identified in people who eat contaminated fish, a major source of low-level exposure. 19 references.

  18. On the ergodicity of supercooled molecular glass-forming liquids at the dynamical arrest: the o-terphenyl case

    PubMed Central

    Mallamace, Francesco; Corsaro, Carmelo; Leone, Nancy; Villari, Valentina; Micali, Norberto; Chen, Sow-Hsin

    2014-01-01

    The dynamics of supercooled ortho-terphenyl has been studied using photon-correlation spectroscopy (PCS) in the depolarized scattering geometry. The obtained relaxation curves are analyzed according to the mode-coupling theory (MCT) for supercooled liquids. The main results are: i) the observation of the secondary Johari-Goldstein relaxation (β) that has its onset just at the dynamical crossover temperature TB (TM > TB > Tg); ii) the confirmation, of the suggestion of a recent statistical mechanical study, that such a molecular system remains ergodic also below the calorimetric glass-transition temperature Tg. Our experimental data give evidence that the time scales of the primary (α) and this secondary relaxations are correlated. Finally a comparison with recent PCS experiments in a colloidal system confirms the primary role of the dynamical crossover in the physics of the dynamical arrest. PMID:24434872

  19. Dipalladium(I) Terphenyl Diphosphine Complexes as Models for Two-Site Adsorption and Activation of Organic Molecules

    PubMed Central

    Lin, Sibo; Herbert, David E.; Velian, Alexandra; Day, Michael W.; Agapie, Theodor

    2013-01-01

    Well-defined models for binding of organic molecules across two metal centers are relatively rare. A paraterphenyl diphosphine was employed to support a dipalladium(I) moiety. Unlike previously reported dipalladium(I) species, the present system provides a single molecular hemisphere for binding of ligands across two metal centers, enabling the characterization and comparison of the binding of a wide variety of saturated and unsaturated organic molecules. The dipalladium(I) terphenyl diphosphine toluene-capped complex was synthesized from a dipalladium(I) hexaacetonitrile precursor in the presence of toluene. The palladium centers display interactions with the π-systems of the central ring of the terphenyl unit and that of the toluene. Exchange of toluene for anisole, 1,3-butadiene, 1,3-cyclohexadiene, thiophenes, pyrroles, or furans resulted in well-defined π-bound complexes which were studied by crystallography, nuclear magnetic resonance (NMR) spectroscopy, and density functional theory. Structural characterization shows that the interactions of the dipalladium unit with the central arene of the diphosphine does not vary significantly in this series allowing for a systematic comparison of the binding of the incoming ligands to the dipalladium moiety. Several of the complexes exhibit rare μ2-η2:η2 or μ2-η2:η1 (O or S) bridging motifs. Hydrogenation of the thiophene and benzothiophene adducts was demonstrated to proceed at room temperature. The relative binding strength of the neutral ligands was determined by competition experiments monitored by NMR spectroscopy. The relative equilibrium constants for ligand substitution span over 13 orders of magnitude. This represents the most comprehensive analysis to date of the relative binding of heterocycles and unsaturated ligands to bimetallic sites. Binding interactions were computationally studied with electrostatic potentials and molecular orbital analysis. Anionic ligands were also demonstrated to form

  20. Polychlorinated biphenyls in tree bark

    SciTech Connect

    Hermanson, M.H.; Hites, R.A. )

    1990-05-01

    Polychlorinated biphenyl (PCB) concentrations in tree bark vary with proximity to a source. Higher total PCB bark/air ratios in areas near contamination show that bark may retain PCB from prior periods of high atmospheric concentrations. Bark is enriched in the more chlorinated PCB homologues relative to air. Congener-specific analyses show that, when compared with air, bark favorably accumulates the less volatile congeners. Lipophilicity is not a good indicator of bark PCB concentrations, but vapor pressure is.

  1. One-dimensional Cu(II) coordination polymers containing C2h-symmetric 1,1':4',1''-terphenyl-3,3'-dicarboxylate linkers.

    PubMed

    Kim, Hyun Chul; Gu, Ja Min; Huh, Seong; Yo, Chul Hyun; Kim, Youngmee

    2015-10-01

    Two new one-dimensional Cu(II) coordination polymers (CPs) containing the C2h-symmetric terphenyl-based dicarboxylate linker 1,1':4',1''-terphenyl-3,3'-dicarboxylate (3,3'-TPDC), namely catena-poly[[bis(dimethylamine-κN)copper(II)]-μ-1,1':4',1''-terphenyl-3,3'-dicarboxylato-κ(4)O,O':O'':O'''] monohydrate], {[Cu(C20H12O4)(C2H7N)2]·H2O}n, (I), and catena-poly[[aquabis(dimethylamine-κN)copper(II)]-μ-1,1':4',1''-terphenyl-3,3'-dicarboxylato-κ(2)O(3):O(3')] monohydrate], {[Cu(C20H12O4)(C2H7N)2(H2O)]·H2O}n, (II), were both obtained from two different methods of preparation: one reaction was performed in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO) as a potential pillar ligand and the other was carried out in the absence of the DABCO pillar. Both reactions afforded crystals of different colours, i.e. violet plates for (I) and blue needles for (II), both of which were analysed by X-ray crystallography. The 3,3'-TPDC bridging ligands coordinate the Cu(II) ions in asymmetric chelating modes in (I) and in monodenate binding modes in (II), forming one-dimensional chains in each case. Both coordination polymers contain two coordinated dimethylamine ligands in mutually trans positions, and there is an additional aqua ligand in (II). The solvent water molecules are involved in hydrogen bonds between the one-dimensional coordination polymer chains, forming a two-dimensional network in (I) and a three-dimensional network in (II). PMID:26422225

  2. Spatial distribution of organochlorine contaminants in soil, sediment, and fish in Bikini and Enewetak Atolls of the Marshall Islands, Pacific Ocean.

    PubMed

    Wang, Jun; Caccamise, Sarah A L; Wu, Liejun; Woodward, Lee Ann; Li, Qing X

    2011-08-01

    Several nuclear tests were performed at Enewetak and Bikini Atolls in the Marshall Islands between 1946 and 1958. The events at Bikini Atoll involved several ships that were tested for durability during nuclear explosions, and 24 vessels now rest on the bottom of the Bikini lagoon. Nine soil samples were collected from different areas on the two islands of the atoll, and eighteen sediment, nine fish, and one lobster were collected in the vicinity of the sunken ships. Organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polychlorinated terphenyls (PCTs) in these samples were analyzed using gas chromatography/ion trap mass spectrometry (GC/ITMS). The average recoveries ranged from 78% to 104% for the different PCB congeners. The limits of detection (LOD) for PCBs, PCTs, DDE, DDT, and dieldrin ranged 10-50 pg g(-1). Some fish from Enewetak contained PCBs at a concentration range of 37-137 ng g(-1), dry weight (dw), and most of the soils from Enewetak showed evidence of PCBs (22-392 ng g(-1)dw). Most of the Bikini lagoon sediment samples contained PCBs, and the highest was the one collected from around the Saratoga, an aircraft carrier (1555 ng g(-1)dw). Some of the fish samples, most of the soil samples, and only one of the sediment samples contained 2,2-bis(4-chlorophenyl)-1,1-dichloroethylene (DDE) and PCBs. In addition to PCBs, the soils from Enewetak Atoll contained PCTs. PCTs were not detected in the sediment samples from Bikini Atoll. The results suggest local pollution sources of PCBs, PCTs, and OCPs. PMID:21616519

  3. Poly(phenylene) and m-Terphenyl as Powerful Protecting Groups for the Preparation of Stable Organic Hydroxides.

    PubMed

    Wright, Andrew G; Weissbach, Thomas; Holdcroft, Steven

    2016-04-01

    Four benzimidazolium hydroxide compounds, in which the C2-position is attached to a phenyl group possessing hydrogen, bromine, methyl groups, or phenyl groups at the ortho positions, are prepared and investigated for stability in a quantitative alkaline stability test. The differences between the stability of the various protecting groups in caustic solutions are rationalized on the basis of their crystal structures and DFT calculations. The highest stability was observed for the m-terphenyl-protected benzimidazolium, showing a half-life in 3 M NaOD/CD3OD/D2O at 80 °C of 3240 h. A high-molecular-weight polymer analogue of this model compound is prepared that exhibits excellent mechanical properties, high ionic conductivity and ion-exchange capacity, as well as remarkable hydroxide stability in alkaline solutions: only 5% degradation after 168 h in 2 M KOH at 80 °C. This is the most stable hydroxide-conducting benzimidazolium polymer to date. PMID:26948285

  4. Polychlorinated biphenyls in honey bees

    SciTech Connect

    Morse, R.A.; Culliney, T.W.; Gutenmann, W.H.; Littman, C.B.; Lisk, D.J.

    1987-02-01

    Honey bees (Apis mellifera L.) may traverse a radius of several miles from their hives and contact innumerable surfaces during their collection of nectar, pollen, propolis and water. In the process, they may become contaminated with surface constituents which are indicative of the type of environmental pollution in their particular foraging area. Honey has also been analyzed as a possible indicator of heavy metal pollution. Insecticides used in the vicinity of bee hives have been found in bees and honey. It has been recently reported that appreciable concentrations of polychlorinated biphenyls (PCBs) have been found in honey bees sampled throughout Connecticut. In the work reported here, an analytical survey was conducted on PCBs in honey bees, honey, propolis and related samples in several states to learn the extent of contamination and possible sources.

  5. POLYCHLORINATED BIPHENYLS AS HORMONALLY ACTIVE STRUCTURAL ANALOGUES

    EPA Science Inventory

    Among the environmental chemicals believed to have the potential to disrupt the endocrine systems of animals including humans, the polychlorinated biphenyls are a chemical class of considerable concern. Possible mechanisms by which these chemicals may interfere with endocrine fun...

  6. Method of removing polychlorinated biphenyl from oil

    DOEpatents

    Cook, G.T.; Holshouser, S.K.; Coleman, R.M.; Harless, C.E.; Whinnery, W.N. III

    1982-03-17

    Polychlorinated biphenyls are removed from oil by extracting the biphenyls into methanol. The mixture of methanol and extracted biphenyls is distilled to separate methanol therefrom, and the methanol is recycled for further use in extraction of biphenyls from oil.

  7. Method of removing polychlorinated biphenyl from oil

    DOEpatents

    Cook, Gus T.; Holshouser, Stephen K.; Coleman, Richard M.; Harless, Charles E.; Whinnery, III, Walter N.

    1983-01-01

    Polychlorinated biphenyls are removed from oil by extracting the biphenyls into methanol. The mixture of methanol and extracted biphenyls is distilled to separate methanol therefrom, and the methanol is recycled for further use in extraction of biphenyls from oil.

  8. Polychlorinated naphthalenes and coplanar polychlorinated biphenyls in arctic air

    SciTech Connect

    Harner, T.; Kylin, H.; Bidleman, T.F.; Barrie, L.A.; Halsall, C.; Strachan, W.M.J.; Fellin, P.

    1998-11-01

    Concentrations of polychlorinated naphthalenes (PCNs) are reported for the first time in arctic air. The data represent combined air samples from the Barents Sea, eastern Arctic Ocean, Norwegian Sea, and two land-based monitoring stations at Alert, Canada, and Dunai Island in eastern Siberia, Russia. Values for {Sigma}PCN were 6--49 for shipboard samples and 0.3--8 for land-based stations and were dominated by the 3-Cl and 4-Cl homologues, which accounted for 90--95% of the total mass. Average values for {Sigma}PCB for the shipboard samples were 126, 24, and 75 for the Barents Sea, eastern Arctic, and Norwegian Sea, respectively. Three-dimensional 5-day air parcel back-trajectories arriving at the ship at 850 and 925 hPa suggested that elevated PCB and PCN concentrations for shipboard samples originated in Europe. Concentrations (fg m{sup {minus}3}) of coplanar PCBs in arctic air were 3--40 (PCB 77) and 0.3--8 (PCB 126) -- about an order of magnitude lower than in urban air. Higher concentrations of PCB 77 and PCB 126, 347 and 5.0 (fg m{sup {minus}3}), respectively, were found in the Barents Sea for two samples with elevated {Sigma}PCBs.

  9. Polychlorinated biphenyls inventory in Belarus.

    PubMed

    Kukharchyk, Tamara I; Kakareka, Sergey V

    2008-09-01

    Polychlorinated biphenyls (PCB) inventory is a key element of the ecologically sound management of these dangerous chemicals. This article presents the findings of the large-scale PCB inventory project that was implemented in Belarus in 2003-2004. Data on PCB-containing equipment of more than 2000 enterprises was recorded: trademarks; volumes of PCBs; dates of manufacture; condition of equipment; levels of operation, descriptions of installations or storage locations. In the course of the inventory about 1500 tones of PCBs were identified, 99% of this total was found in power transformers and capacitors. As it proved most equipment containing PCBs is still in service today due to its long life-time. Additionally, the PCB-containing equipment which has been taken out of service is primarily stored on the territory of enterprises. The distribution of PCBs in Belarus among economy sectors as well as regions is shown. Problems of the PCB inventory and disposal are discussed. It is shown that the inventory needs to be regularly updated in order to estimate temporal changes in PCB-containing equipment condition, current owners and a location. PMID:17597287

  10. Polychlorinated biphenyls in commercial buildings

    SciTech Connect

    Baechler, M.C.; Foley, L.O.; Jarnagin, R.E.

    1990-09-01

    The Bonneville Power Administration (Bonneville) is planning to implement a conservation acquisition program in new and existing commercial buildings. In anticipation of that program, Bonneville is examining the potential environmental effects of conservation measures in commercial buildings. An important conservation measure is the installation of new energy-efficient lighting fixtures. Some of the old lighting fixtures that these new lights will be replacing were manufactured before 1978, when polychlorinated biphenyls (PCBs) were still used in the capacitors of the lighting ballasts. This report focuses on a summary of information about PCBs in fluorescent light fixtures manufactured before 1978. A key issue associated with these PCBs is the potential effect of lamp change-outs on ballast failure. The US Environmental Protection Agency (EPA) speculates that installing energy-efficient lamps in old, PCB-laden ballasts may contribute to ballast failure and PCB leaks, which is addressed in Section 3 of this report. Section 2 discusses applicable standards and regulations; Section 4 describes PCB concentrations in commercial buildings. Sections 5 and 6 discuss cleanup practices and disposal options. 4 tabs.

  11. Bioelectrochemical Immunoassay of Polychlorinated Biphenyl

    SciTech Connect

    Lin, Ying-Ying; Liu, Guodong; Wai, Chien M.; Lin, Yuehe

    2008-04-01

    A simple, rapid, and highly sensitive bioelectrochemical immunoassay method based on magnetic beads (MBs) and disposable screen-printed electrodes (SPE) has been developed to detect polychlorinated biphenyls (PCBs). The principle of this bioassay is based on a direct competitive enzyme-linked immunosorbent assay using PCB-antibody-coated MBs and horseradish peroxidase (HRP)-labeled PCB (HRP-PCB). A magnetic process platform was used to mix and shake the samples during the immunoreactions and to separate free and unbound reagents after the liquid-phase competitive immunoreactions among PCB-antibody-coated MBs, PCB analyte, and HRP-PCB. After a complete immunoassay, the HRP tracers attached to MBs were transferred to a substrate solution containing o-aminophenol and hydrogen peroxide for electrochemical detection. The different parameters, including the amount of HRP-PCB conjugates, immunoreaction time, and the concentration of substrate that governs the analytical performance of the immunoassay have been studied in detail and optimized. The detection limit of 5 pg mL-1 was obtained under optimum experimental conditions. The performance of this bioelectrochemical immunoassay was successfully evaluated with untreated river water spiked with PCBs, and the results were validated by commercial PCB enzyme-linked immunosorbent assay kit, indicating that this convenient and sensitive technique offers great promise for decentralized environmental application and trace PCBs monitoring.

  12. EMISSIONS OF POLYCHLORINATED DIBENZO-P-DIOXINS AND POLYCHLORINATED DIBENZOFURANS FROM THE OPEN BURNING OF HOUSEHOLD WASTE IN BARRELS

    EPA Science Inventory

    Backyard burning of household waste in barrels is a common waste disposal practice for which pollutant emissions have not been well characterized. This study measured the emissions of several pollutants, including polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofura...

  13. ASSESSMENT OF PCDDS (POLYCHLORINATED DIBENZODIOXINS) AND PCDFS (POLYCHLORINATED DIBENZOFURANS) FROM PCB (POLYCHLORINATED BIPHENYL'S) TRANSFORMER AND CAPACITOR FIRES

    EPA Science Inventory

    The EPA, under the Toxic Substances Control Act, has been mandated to develop appropriate regulations for the control of exposure to polychlorinated biphenyls (PCBs). In light of this responsibility the EPA Office of Toxic Substances recently issued an Advance Notice of Proposed ...

  14. POLYCHLORINATED BIPHENYL AND POLYCHLORINATED DIBENZOFURAN BIOMARKERS OF RISK ASSESSMENT IN ADOLESCENT CHILDREN AND THEIR MOTHERS

    EPA Science Inventory

    This is two cohort comparison study of endocrine and cytochrome P450 family 1 biomarkers for risk assessment of polychlorinalted biphenyls (PCBs)/polychlorinated dibenzofurans (PCDFs) induced developmental toxicities in the human. The subjects will be sexually mature adoles...

  15. The role of isomerization in the kinetics of self-assembly: p-terphenyl-m-dicarbonitrile on the Ag(111) surface.

    PubMed

    Abbasi-Pérez, David; Recio, J Manuel; Kantorovich, Lev

    2015-05-01

    Using a toolkit of theoretical techniques comprising ab initio density functional theory calculations, the nudged elastic band method and kinetic Monte Carlo (KMC) modeling, we investigate in great detail how para-terphenyl-meta-dicarbonitrile (pTmDC) molecules diffuse and isomerize to self-assemble on the Ag(111) surface. We show that molecules "walk" on the surface via a pivoting mechanism moving each of its two "legs" one at a time. We then identify a peculiar "under-side" isomerization mechanism capable of changing the molecules chirality, and demonstrate that it is fundamental in understanding the growth of hydrogen bonding assembles of ribbons, linkers, clusters and brickwall islands on the Ag(111) surface, as observed in recent scanning tunneling microscopy experiments (ChemPhysChem, 2010, 11, 1446). The discovered underlying atomistic mechanism of self-assembly may be behind the growth of other hydrogen bonding structures of chiral molecules on metal surfaces. PMID:25760805

  16. CORRELATION OF POLYCHLORINATED NAPHTHALENES WITH POLYCHLORINATED DIBENZOFURANS FORMED FROM WASTE INCINERATION

    EPA Science Inventory

    Isomer composition of polychlorinated naphthalenes (PCNs) was measured for municipal waste incinerator fly ash samples,and for emission samples produced from soot and copper deposit experiments conducted at EPA. Two types of PCN isomer patterns were identified. One pattern cxonta...

  17. Waste disposal technologies for polychlorinated biphenyls.

    PubMed Central

    Piver, W T; Lindstrom, F T

    1985-01-01

    Improper practices in the disposal of polychlorinated biphenyl (PCB) wastes by land burial, chemical means and incineration distribute these chemicals and related compounds such as polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzodioxins (PCDDs) throughout the environment. The complete range of methods for disposal that have been proposed and are in use are examined and analyzed, with emphasis given to the two most commonly used methods: land burial and incineration. The understanding of aquifer contamination caused by migration of PCBs from subsurface burial sites requires a description of the physical, chemical and biological processes governing transport in unsaturated and saturated soils. For this purpose, a model is developed and solved for different soil conditions and external driving functions. The model couples together the fundamental transport phenomena for heat, mass, and moisture flow within the soil. To rehabilitate a contaminated aquifer, contaminated groundwaters are withdrawn through drainage wells, PCBs are extracted with solvents or activated carbon and treated by chemical, photochemical or thermal methods. The chemical and photochemical methods are reviewed, but primary emphasis is devoted to the use of incineration as the preferred method of disposal. After discussing the formation of PCDFs and PCDDs during combustion from chloroaromatic, chloroaliphatic, as well as organic and inorganic chloride precursors, performance characteristics of different thermal destructors are presented and analyzed. To understand how this information can be used, basic design equations are developed from governing heat and mass balances that can be applied to the construction of incinerators capable of more than 99.99% destruction with minimal to nondetectable levels of PCDFs and PCDDs. PMID:3921358

  18. Metabolism and metabolites of polychlorinated biphenyls (PCBs)

    PubMed Central

    Grimm, FA; Hu, D; Kania-Korwel, I; Lehmler, HJ; Ludewig, G; Hornbuckle, KC; Duffel, MW; Bergman, A; Robertson, LW

    2015-01-01

    The metabolism of polychlorinated biphenyls (PCBs) is complex and has an impact on toxicity and thereby assessment of PCB risks. A large number of reactive and stable metabolites are formed in the processes of biotransformation in biota in general and in humans in particular. The aim of this document is to provide an overview of PCB metabolism and to identify metabolites of concern and their occurrence. Emphasis is given to mammalian metabolism of PCBs and their hydroxyl, methylsulfonyl, and sulfated metabolites, especially those that persist in human blood. Potential intracellular targets and health risks are also discussed. PMID:25629923

  19. THE IMPORTANCE OF CHLORINE SPECIATION ON DE NOVO FORMATION OF POLYCHLORINATED DIBENZO-P-DIOXINS AND POLYCHLORINATED DIBENZOFURANS

    EPA Science Inventory

    The role of chlorine speciation on de novo formation of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/Fs) has been thoroughly studied in an entrained flow reactor during simulated waste combustion. Namely, the affects of gas-phase chlorine species suc...

  20. THE EFFECT OF COFIRING HIGH-SULFUR COAL WITH MUNICIPAL WASTE ON FORMATION OF POLYCHLORINATED DIBENZODIOXIN AND POLYCHLORINATED DIBENZOFURAN

    EPA Science Inventory

    The effect of co-firing minor amounts (5-10 wt%) of high sulfur coal with municipal refuse-derived fuel (RDF) on emissions of polychlorinated dibenzo-p-dioxin (PCDD) and polychlorinated dibenzofuran (PCDF) was studied under a range of operating conditions. Through use of 2x facto...

  1. ON-ROAD SAMPLING OF DIESEL ENGINE EMISSIONS OF POLYCHLORINATED DIBENZO-P-DIOXIN AND POLYCHLORINATED DIBENZOFURAN

    EPA Science Inventory

    The first known program to sample mobile heavy duty diesel engine emissions for polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran ("PCDD/F") during highway and in-city driving routes was conducted. The post-muffler stacks of two diesel tractors hauling loaded tra...

  2. ON-ROAD EMISSION SAMPLING OF A HEAVY DUTY DIESEL VEHICLE FOR POLYCHLORINATED DIBENZO-P-DIOXINS AND POLYCHLORINATED DIBENZOFURANS

    EPA Science Inventory

    The first known program to characterize mobile heavy diesel vehicle emissions for polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/Fs) during highway and in-city driving routes was successfully conducted. The post-muffler exhaust of a diesel tractor haul...

  3. THE EFFECT OF METAL CATALYSTS ON THE FORMATION OF POLYCHLORINATED DIBENZO-P-DIOXIN AND POLYCHLORINATED DIBENZOFURAN PRECURSORS

    EPA Science Inventory

    The catalytic effects of copper and iron compounds were examined for their behavior in promoting formation of chlorine (Cl2), the major chlorinating agent of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), in an environment simulati...

  4. Process for removing polychlorinated biphenyls from soil

    DOEpatents

    Hancher, C.W.; Saunders, M.B.; Googin, J.M.

    1984-11-16

    The present invention relates to a method of removing polychlorinated biphenyls from soil. The polychlorinated biphenyls are extracted from the soil by employing a liquid organic solvent dispersed in water in the ratio of about 1:3 to 3:1. The organic solvent includes such materials as short-chain hydrocarbons including kerosene or gasoline which are immiscible with water and are nonpolar. The organic solvent has a greater affinity for the PCB's than the soil so as to extract the PCB's from the soil upon contact. The organic solvent phase is separated from the suspended soil and water phase and distilled for permitting the recycle of the organic solvent phase and the concentration of the PCB's in the remaining organic phase. The present process can be satisfactorily practiced with soil containing 10 to 20% petroleum-based oils and organic fluids such as used in transformers and cutting fluids, coolants and the like which contain PCB's. The subject method provides for the removal of a sufficient concentration of PCB's from the soil to provide the soil with a level of PCB's within the guidelines of the Environmental Protection Agency.

  5. ROLE OF COMBUSTION AND SORBENT PARAMETERS IN PREVENTION OF POLYCHLORINATED DIBENZO-P-DIOXIN AND POLYCHLORINATED DIBENZOFURAN FORMATION DURING WASTE COMBUSTION

    EPA Science Inventory

    This research uses experimental data and a statistical approach to determine the effect of combustion- and sorbent-injection-related parameters on the mechanism of polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran (PCDD and PCDF, respectively) formation and preven...

  6. Degradation of polychlorinated naphthalene by mechanochemical treatment.

    PubMed

    Nomura, Yugo; Aono, Sho; Arino, Takashi; Yamamoto, Takashi; Terada, Akihiko; Noma, Yukio; Hosomi, Masaaki

    2013-11-01

    Polychlorinated naphthalene (PCN) is a hazardous compound that is listed as a new persistent organic pollutants candidate by the United Nations Environment Program. The production, import and use of PCNs are prohibited by the Chemical Substances Control Law in Japan. PCN was milled with calcium oxide as an additive to investigate the feasibility of its degradation by mechanochemical treatment. The milling process cleaved the C-C and C-Cl bonds by the mechanically induced solid-state reaction. Gas chromatography/mass spectrometry analysis confirmed that the PCN was decomposed after 1h milling. The yield of chloride ions reached 100% after 3h milling. This indicates that all PCN was broken down into inorganic compounds after milling, thereby maintaining the chlorine mass balance through the reaction. This experiment, for the first time, exhibited the effectiveness of mechanochemical treatment as a PCN degradation method. PMID:24094772

  7. Testing for polychlorinated biphenyls in human milk

    SciTech Connect

    Wickizer, T.M.; Brilliant, L.B.

    1981-09-01

    Reports of polychlorinated biphenyl (PCB) contamination of human milk have raised questions about the possible risks of breast-feeding and whether nursing mothers ought to have their breast milk tested. Current data on contamination of human milk are needed so that pediatricians can make informed recommendations about breast milk testing and breast-feeding. With consideration of recent findings of PCB contamination of human milk in Michigan, recommendations concerning breast milk testing and breast-feeding are made. No major changes in current breast-feeding practices are advised. However, breast milk testing is recommended for certain nursing mothers who have had potentially high exposure to PCBs. Limiting the duration of breast-feeding may also be advisable for mothers with high PCB milk fat levels in order to reduce infant exposure to PCBs.

  8. Polychlorinated biphenyls: influence on birthweight and gestation

    SciTech Connect

    Taylor, P.R.; Lawrence, C.E.; Hwang, H.L.; Paulson, A.S.

    1984-10-01

    Fifty-one infants born to women employed at two capacitor manufacturing facilities with a history of high exposure to polychlorinated biphenyls (PCBs) had a mean birthweight of 153 grams less than that of 337 infants born to women who had worked in low-exposure areas (90 per cent confidence interval, -286 to -20 g); mean gestational age was 6.6 days shorter in the high-exposure infants (90 per cent CI, -10.3 to -2.9 days). After adjusting for gestational age, the difference in birthweight was markedly reduced, indicating that the observed reduction in birthweight was due mainly to shortening of gestational age in the high-exposure group.

  9. PRACTICAL APPROACHES TO REMEDIATION OF POLYCHLORINATED BIPHENYLS IN SEDIMENTS

    EPA Science Inventory

    Polychlorinated biphenyls (PCBs) are one group of persistent organic pollutants (POPs) of international concern because of global distribution, persistence, and toxicity. Removal of these compounds from the environment presents a very tough challenge because they are highly hydro...

  10. POLYCHLORINATED DIOXIN AND FURAN DISCHARGE DURING CARBON REACTIVATION (JOURNAL VERSION)

    EPA Science Inventory

    Analyses are performed on samples collected from various effluent streams of a fluidized-bed and infrared furnace during reactivation of granular activated carbon (GAC) used in treatment of drinking water. These analyses show that polychlorinated dibenzodioxins (PCDDs) and polych...

  11. DECHLORINATIONS OF POLYCHLORINATED BIPHENYLS IN SEDIMENTS OF NEW BEDFORD HARBOR

    EPA Science Inventory

    The breakdown of polychlorinated biphenyl (PCB) congeners in situ in sediments heavily contaminated with PCBs by processes called reductive dechlorinations have been reported. hese studies characterized several distinct dechlorination patterns, caused by different strains of anae...

  12. ENANTIOMER SEPARATION OF POLYCHLORINATED BIPHENYL ATROPISOMERS AND POLYCHLORINATED BIPHENYL RETENTION BEHAVIOR ON MODIFIED CYCLODEXTRIN CAPILLARY GAS CHROMATOGRAPHY COLUMNS

    EPA Science Inventory

    Seven commercially-available chiral capillary gas chromatography columns containing modified cyclodextrins were evaluated for their ability to separate enantiomers of the 19 stable chiral polychlorinated biphenyl (PCB) atropisomers, and for their ability to separate these enantio...

  13. Syntheses, structures and properties of metal-carboxylate chain-based coordination polymers (CPs) with 1,1‧:4‧,1″-terphenyl-2‧,4,4″,5‧-tetracarboxylate

    NASA Astrophysics Data System (ADS)

    Zhou, Xinhui; Song, Lin; Li, Liang; Yang, Tao

    2016-09-01

    Two coordination polymers (CPs) {[Mg2L(μ2-H2O) (μ2-DMA)]·DMA}n (1), and [Ag4L(DMF)2]n (2) (H4L = 1,1‧:4‧,1″-terphenyl-2‧,4,4″,5‧-tetracarboxylic acid, DMA = N,N-dimethylacetamine, DMF = N,N-dimethylformamide) have been synthesized and structurally characterized. In 1 and 2, there exist a series of parallel aligned Msbnd Osbnd C chains, which are linked along two directions by para-terphenyl moieties of L4- ligands to lead to the metal-carboxylate chain-based three-dimensional frameworks. The photoluminescence properties of the compounds 1 and 2 have also been investigated. 1 displays blue-violet light emission with the emission maximum at 380 nm. 2 exhibits a broad emission peak from 300 to 800 nm with an emission maximum at 484 nm and some of the shoulder peaks.

  14. Polychlorinated biphenyls and links to cardiovascular disease.

    PubMed

    Perkins, Jordan T; Petriello, Michael C; Newsome, Bradley J; Hennig, Bernhard

    2016-02-01

    The pathology of cardiovascular disease is multi-faceted, with links to many modifiable and non-modifiable risk factors. Epidemiological evidence now implicates exposure to persistent organic pollutants, such as polychlorinated biphenyls (PCBs), with an increased risk of developing diabetes, hypertension, and obesity; all of which are clinically relevant to the onset and progression of cardiovascular disease. PCBs exert their cardiovascular toxicity either directly or indirectly via multiple mechanisms, which are highly dependent on the type and concentration of PCBs present. However, many PCBs may modulate cellular signaling pathways leading to common detrimental outcomes including induction of chronic oxidative stress, inflammation, and endocrine disruption. With the abundance of potential toxic pollutants increasing globally, it is critical to identify sensible means of decreasing associated disease risks. Emerging evidence now implicates a protective role of lifestyle modifications such as increased exercise and/or nutritional modulation via anti-inflammatory foods, which may help to decrease the vascular toxicity of PCBs. This review will outline the current state of knowledge linking coplanar and non-coplanar PCBs to cardiovascular disease and describe the possible molecular mechanism of this association. PMID:25877901

  15. Can Stress Enhance Phytoremediation of Polychlorinated Biphenyls?

    PubMed Central

    Kalinowski, Tomasz; Halden, Rolf U.

    2012-01-01

    Abstract Phytoremediation—plant-facilitated remediation of polluted soil and groundwater—is a potentially effective treatment technology for the remediation of heavy metals and certain organic compounds. However, contaminant attenuation rates are often not rapid enough to make phytoremediation a viable option when compared with alternative treatment approaches. Different strategies are being employed to enhance the efficacy of phytoremediation, including modification to the plant genome, inoculation of the rhizosphere with specialized and/or engineered bacteria, and treatment of the soil with supplementary chemicals, such as surfactants, chelators, or fertilizers. Despite these efforts, greater breakthroughs are necessary to make phytoremediation a viable technology. Here, we introduce and discuss the concept of integrating controlled environmental stresses as a strategy for enhancing phytoremediation. Plants have a diverse suite of defense mechanisms that are only induced in response to stress. Here, we examine some stress-response mechanisms in plants, focusing on defenses involving physiological changes that alter the soil microenvironment (rhizosphere), and outline how these defense mechanisms can be co-opted to enhance the effectiveness of phytoremediation of polychlorinated biphenyls and other contaminants. PMID:23236249

  16. Inadvertent Polychlorinated Biphenyls in Commercial Paint Pigments†

    PubMed Central

    2009-01-01

    A polychlorinated biphenyl (PCB) that was not produced as part of the Aroclor mixtures banned in the 1980s was recently reported in air samples collected in Chicago, Philadelphia, the Arctic, and several sites around the Great Lakes. In Chicago, the congener 3,3′-dichlorobiphenyl or PCB11 was found to be the fifth most concentrated congener and ubiquitous throughout the city. The congener exhibited strong seasonal concentration trends that suggest volatilization of this compound from common outdoor surfaces. Due to these findings and also the compound’s presence in waters that received waste from paint manufacturing facilities, we hypothesized that PCB11 may be present in current commercial paint. In this study we measured PCBs in paint sold on the current retail market. We tested 33 commercial paint pigments purchased from three local paint stores. The pigment samples were analyzed for all 209 PCB congeners using gas chromatography with tandem mass spectrometry (GC-MS/MS). More than 50 PCB congeners including several dioxin-like PCBs were detected, and the PCB profiles varied due to different types of pigments and different manufacturing processes. PCB congeners were detected in azo and phthalocyanine pigments which are commonly used in paint but also in inks, textiles, paper, cosmetics, leather, plastics, food and other materials. Our findings suggest several possible mechanisms for the inadvertent production of specific PCB congeners during the manufacturing of paint pigments. PMID:19957996

  17. Reactive Functionalized Membranes for Polychlorinated Biphenyl Degradation

    PubMed Central

    Gui, Minghui; Ormsbee, Lindell E.; Bhattacharyya, Dibakar

    2014-01-01

    Membranes have been widely used in water remediation (e.g. desalination and heavy metal removal) because of the ability to control membrane pore size and surface charge. The incorporation of nanomaterials into the membranes provides added benefits through increased reactivity with different functionality. In this study, we report the dechlorination of 2-chlorobiphenyl in the aqueous phase by a reactive membrane system. Fe/Pd bimetallic nanoparticles (NPs) were synthesized (in-situ) within polyacrylic acid (PAA) functionalized polyvinylidene fluoride (PVDF) membranes for degradation of polychlorinated biphenyls (PCBs). Biphenyl formed in the reduction was further oxidized into hydroxylated biphenyls and benzoic acid by an iron-catalyzed hydroxyl radical (OH•) reaction. The formation of magnetite on Fe surface was observed. This combined pathway (reductive/oxidative) could reduce the toxicity of PCBs effectively while eliminating the formation of chlorinated degradation byproducts. The successful manufacturing of full-scale functionalized membranes demonstrates the possibility of applying reactive membranes in practical water treatment. PMID:24954974

  18. Inadvertent polychlorinated biphenyls in commercial paint pigments.

    PubMed

    Hu, Dingfei; Hornbuckle, Keri C

    2010-04-15

    A polychlorinated biphenyl (PCB) that was not produced as part of the Aroclor mixtures banned in the 1980s was recently reported in air samples collected in Chicago, Philadelphia, the Arctic, and several sites around the Great Lakes. In Chicago, the congener 3,3'-dichlorobiphenyl or PCB11 was found to be the fifth most concentrated congener and ubiquitous throughout the city. The congener exhibited strong seasonal concentration trends that suggest volatilization of this compound from common outdoor surfaces. Due to these findings and also the compound's presence in waters that received waste from paint manufacturing facilities, we hypothesized that PCB11 may be present in current commercial paint. In this study we measured PCBs in paint sold on the current retail market. We tested 33 commercial paint pigments purchased from three local paint stores. The pigment samples were analyzed for all 209 PCB congeners using gas chromatography with tandem mass spectrometry (GC-MS/MS). More than 50 PCB congeners including several dioxin-like PCBs were detected, and the PCB profiles varied due to different types of pigments and different manufacturing processes. PCB congeners were detected in azo and phthalocyanine pigments which are commonly used in paint but also in inks, textiles, paper, cosmetics, leather, plastics, food and other materials. Our findings suggest several possible mechanisms for the inadvertent production of specific PCB congeners during the manufacturing of paint pigments. PMID:19957996

  19. PCDDs (polychlorinated dibenzo-p-dioxins) and PCDFs (polychlorinated dibenzofurans) in humans

    SciTech Connect

    Swanson, S.E. ); Erickson, M.D. )

    1990-01-01

    Numerous instances of human exposure to polychlorinated dibenzo-p- dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) have been documented. Following the development of sufficiently specific and sensitive analytical methods during the past few years, many reports have appeared on PCDD and PCDF levels in human blood and adipose tissues. Studies have examined the PCDD and PCDF levels resulting from accidental and occupational exposures of various groups, including chemical plant workers, forestry and tannery workers, and Niet Nam veterans who had handled Agent Orange. The general background levels in the US, Federal Republic of Germany, Japan, and Sweden were also determined. The results of these studies indicate that a background level of PCDDs and PCDFs is present in the overall population. In some cases, individuals exposed to specific PCDDs or PCDFs exhibit higher levels than the general population. Isomer distribution patterns are relatively consistent and indicative of sources and metabolism. This paper reviews the available data on human PCDD and PCDF levels in exposed and general populations. 15 refs., 4 figs.

  20. Photodegradation of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans: direct photolysis and photocatalysis processes.

    PubMed

    Wu, Chung-Hsin; Ng, How-Yong

    2008-03-01

    This study employed direct photolysis to treat mixed polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) solutions. The solutions included a synthetic standard 17 2, 3, 7, 8-substituted congeners solution and a practical liquid extracted from the bag filter ash of an electric arc furnace. Additionally, this work utilized a coupled catalyst (ZnO/SnO2) under UV irradiation for photocatalytic degradation of 1, 2, 3, 6, 7, 8-HxCDD and OCDD. The direct photolysis rate of PCDFs was faster than that of PCDDs. The degradation rate of international toxicity equivalency quantity (I-TEQ) for PCDDs and PCDFs in the synthetic standard solution was 1.369 and 1.472 h(-1), respectively, and that in the ash-extracted solution was 0.061 and 0.117 h(-1), respectively. The rate of photocatalytic degradation declined as the number of chlorine atoms increased. No 2, 3, 7, 8-substituted congeners were identified during photocatalytic degradation; additionally, the photolytic rate of the UV/coupled catalyst was higher than that of UV/single catalyst system. Experimental results suggested that the primary degradation pathway for direct photolysis and photocatalysis of PCDD/Fs was the CCl cleavage and CO cleavage, respectively. PMID:17656019

  1. Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in municipal and industrial effluents.

    PubMed

    Sappington, Emily N; Balasubramani, Aparna; Rifai, Hanadi S

    2015-08-01

    Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) were quantified in 45 effluent samples in the Houston Ship Channel (HSC) system in Texas. Total PCDD/F concentrations ranged from 0.16 to 13.23 pg L(-1) in the dissolved phase and from 0.79 to 682.27 pg L(-1) in the suspended phase. Generally, industrial facilities contained more PCDD/F contamination than municipal wastewater treatment plants or refuse facilities. World Health Organization Toxic Equivalents (WHO-TEQs) ranged from 0.007 to 0.279 pg L(-1) in the dissolved phase and 0.021-1.851 pg L(-1) in the suspended phase. The major TEQ contributor was 2,3,7,8-TCDD and overall, TEQs were greatest in industrial effluents. A correlation between high solids and high PCDD/F concentrations was observed and based on the results obtained in this study, the abundance of suspended solids may have largely contributed to high PCDD/F contamination in the suspended phase. Homolog profiles revealed that PCDD/F contamination increased with increasing chlorination and the highest concentrations were primarily from the octa-chlorinated congeners (OCDD/F) in both the dissolved and suspended phase. PMID:25935498

  2. Human dietary exposure to polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in Taiwan.

    PubMed

    Wang, I-Ching; Wu, Yee-Lin; Lin, Long-Full; Chang-Chien, Guo-Ping

    2009-05-30

    Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) levels in a total of 25 food items in Taiwan were surveyed. It was observed that shellfish and saltwater fish possessed the highest PCDD/Fs levels, 9.82 and 3.60 pg WHO-TEQ/g, respectively, on the lipid basis. The dietary intakes of humans at the ages of 12-18, 19-64, and over 65 were determined. The estimated intake were between 21.8 pg (female teenagers) and 37.6 pg (male seniors) WHO-TEQ/day; the levels varied with the dietary habits. The PCDD/F intakes for all human groups are far below the tolerable limit of 70 pg WHO-TEQ/kg b.w./month. In addition, the daily PCDD/F intake levels for duck-farmers consuming average and large amounts of PCDD/F contaminated duck eggs were examined. The result shows that consuming more than one duck egg with level higher than 10 pg WHO-TEQ/g lipid of PCDD/Fs per day could lead to a PCDD/F intake level higher than the tolerable limit. However, for normal population, there is a little risk to ingest intolerable amount of PCDD/Fs because of consuming contaminated duck eggs. PMID:18829161

  3. 75 FR 34076 - Polychlorinated Biphenyls (PCBs); Reassessment of Use Authorizations; Extension of Comment Period...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-16

    ... AGENCY 40 CFR Part 761 RIN 2070-AJ38 Polychlorinated Biphenyls (PCBs); Reassessment of Use Authorizations..., Hazardous substances, Labeling, Polychlorinated biphenyls (PCBs), Reporting and recordkeeping requirements..., 2010, concerning the reassessment of the use authorizations for PCBs. This document extends the...

  4. Pilot Survey of Levels of Polychlorinated Dibenzo-P-Dioxins (Pcdds), Polychlorinated Dibenzofurans (Pcdfs), Polychlorinated Biphenyls (PCB) and Mercury in Rural Soils of the U.S.

    EPA Science Inventory

    Cover of the Pilot Survey Soil Report EPA has released a final report entitled, Pilot Survey of Levels of Polychlorinated Dibenzo-p-dioxins, Polychl...

  5. A Survey of Polychlorinated Dibenzo-p-dioxins, Polychlorinated Dibenzofurans and Co-planar Polychlorinated Biphenyls in U.S. Meat and Poultry, 2007-2008

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A statistically-based survey of dioxins and dioxin-like compounds in domestic meat and poultry was conducted by the U.S. Department of Agriculture (USDA) from September 2007 to September 2008. Seventeen toxic polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and three coplanar pol...

  6. Process for gamma ray induced degradation of polychlorinated biphenyls

    DOEpatents

    Meikrantz, D.H.; Mincher, B.J.; Arbon, R.E.

    1998-08-25

    The invention is a process for the in-situ destruction of polychlorinated biphenyl (PCB) compounds in transformer oils and transformers. These compounds are broken down selectively by irradiation of the object or mixture using spent nuclear fuel or any isotopic source of high energy gamma radiation. For example, the level of applied dose required to decompose 400 ppm of polychlorinated biphenyl in transformer oil to less than 50 ppm is 500 kilograms. Destruction of polychlorinated biphenyls to levels of less than 50 ppm renders the transformer oil or transformer non-PCB contaminated under current regulations. Therefore, this process can be used to treat PCB contaminated oil and equipment to minimize or eliminate the generation of PCB hazardous waste. 5 figs.

  7. Process for gamma ray induced degradation of polychlorinated biphenyls

    DOEpatents

    Meikrantz, David H.; Mincher, Bruce J.; Arbon, Rodney E.

    1998-01-01

    The invention is a process for the in-situ destruction of polychlorinated biphenyl (PCB) compounds in transformer oils and transformers. These compounds are broken down selectively by irradiation of the object or mixture using spent nuclear fuel or any isotopic source of high energy gamma radiation. For example, the level of applied dose required to decompose 400 ppm of polychlorinated biphenyl in transformer oil to less than 50 ppm is 500 kilogray. Destruction of polychlorinated biphenyls to levels of less than 50 ppm renders the transformer oil or transformer non-PCB contaminated under current regulations. Therefore, this process can be used to treat PCB contaminated oil and equipment to minimize or eliminate the generation of PCB hazardous waste.

  8. Polychlorinated biphenyls as hormonally active structural analogues

    SciTech Connect

    McKinney, J.D. ); Waller, C.L. )

    1994-03-01

    Among the environmental chemicals that may be able to disrupt the endocrine systems of animals and humans, the polychlorinated biphenyls (PCBs) are a chemical class of considerable concern. One possible mechanism by which PCBs may interfere with endocrine function is their ability to mimic natural hormones. These actions reflect a close relationship between the physicochemical properties encoded in the PCB molecular structure and the responses they evoke in biological systems. These physiocochemical properties determine the molecular reactivities of PCBs and are responsible for their recognition as biological acceptors and receptors, as well as for triggering molecular mechanisms that lead to tissue response. [open quotes]Coplanarity[close quotes] of PCB phenyl rings and [open quotes]laterality[close quotes] of chlorine atoms are important structural features determining specific binding behavior with proteins and certain toxic responses in biological systems. We compare qualitative structure-activity relationships for PCBs with the limited information on the related non-coplanar chlorinated diphenyl ethers, providing further insights into the nature of the molecular recognition processes and support for the structural relationship of PCBs to thyroid hormones. Steriodlike activity requires conformational restriction and possibility hydroxylation. We offer some simple molecular recognition models to account for the importance of these different structural features in the structure-activity relationships that permit one to express PCB reactivities in terms of dioxin, thyroxine, and estradiol equivalents. The available data support the involvement of PCBs as mimics of thyroid and other steroidal hormones. The potential for reproductive and developmental toxicity associated with human exposure to PCBs is of particular concern. 53 refs., 6 figs.

  9. Seasonal variation of atmospheric polychlorinated biphenyls and polychlorinated naphthalenes in Japan

    NASA Astrophysics Data System (ADS)

    Hogarh, Jonathan N.; Seike, Nobuyasu; Kobara, Yuso; Masunaga, Shigeki

    2013-12-01

    This study investigated the seasonality of atmospheric polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs) in Japan. Polyurethane foam (PUF) disk passive air samplers (PAS) were deployed simultaneously at 55 sites in spring 2008, summer 2008 and winter 2008/09. Sampler deployment spanned 8 continuous weeks in each season. The non-outlier ranges of the two pollutants (ng/sample) were as follows; ∑190PCBs: 6.5-38.6 (spring), 43.5-220.5 (summer) and 25.9-136 (winter); and ∑63PCNs: 0.4-3.9 (spring), 0.7-7.1 (summer) and 1.1-9.2 (winter). The corresponding values in air were ∑190PCBs (pg m-3): 33-197 (spring), 222-1125 (summer) and 132-694 (winter); and ∑63PCNs (pg m-3): 2.2-20 (spring), 3.5-36 (summer) and 5.7-47 (winter), when sampling rate of 3.5 m3 day-1 was assumed. Thus, the PCBs peaked in summer, while the PCNs mostly peaked in winter; there was an apparent contrast in their seasonality in Japan. For the PCNs, seasonal variability was significant at rural than urban sites. Normally, POPs would show relatively increased air content in summer due to vaporization effect. The PCNs appeared to deviate from such a trend because of overriding input of tri-CNs presumably transported from long range by northwesterly winds in the winter season. The dioxin-like fractions of either pollutant were reduced in winter by about 30-50%.

  10. Mammalian Cytochrome P450-Dependent Metabolism of Polychlorinated Dibenzo-p-dioxins and Coplanar Polychlorinated Biphenyls

    PubMed Central

    Inui, Hideyuki; Itoh, Toshimasa; Yamamoto, Keiko; Ikushiro, Shin-Ichi; Sakaki, Toshiyuki

    2014-01-01

    Polychlorinated dibenzo-p-dioxins (PCDDs) and coplanar polychlorinated biphenyls (PCBs) contribute to dioxin toxicity in humans and wildlife after bioaccumulation through the food chain from the environment. The authors examined human and rat cytochrome P450 (CYP)-dependent metabolism of PCDDs and PCBs. A number of human CYP isoforms belonging to the CYP1 and CYP2 families showed remarkable activities toward low-chlorinated PCDDs. In particular, human CYP1A1, CYP1A2, and CYP1B1 showed high activities toward monoCDDs, diCDDs, and triCDDs but no detectable activity toward 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-tetraCDD). Large amino acids located at putative substrate-recognition sites and the F-G loop in rat CYP1A1 contributed to the successful metabolism of 2,3,7,8-tetraCDD. Rat, but not human, CYP1A1 metabolized 3,3',4,4',5-pentachlorobiphenyl (CB126) to two hydroxylated metabolites. These metabolites are probably less toxic than is CB126, due to their higher solubility. Homology models of human and rat CYP1A1s and CB126 docking studies indicated that two amino acid differences in the CB126-binding cavity were important for CB126 metabolism. In this review, the importance of CYPs in the metabolism of dioxins and PCBs in mammals and the species-based differences between humans and rats are described. In addition, the authors reveal the molecular mechanism behind the binding modes of dioxins and PCBs in the heme pocket of CYPs. PMID:25123135

  11. Effect of metal catalysts on the formation of polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran precursors (reannouncement)

    SciTech Connect

    Gullett, B.K.; Bruce, K.R.; Beach, L.O.

    1990-01-01

    The paper gives results of an examination of the catalytic effects of copper and iron compounds for their behavior in promoting formation of chlorine (Cl2), the major chlorinating agent of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), in an environment simulating that of municipal waste fly ash. Cl2 formed as a result of a metal-catalyzed reaction of HCl with O2. Catalytic activity was greatest at a temperature of about 400 C, supporting a theory of de novo synthesis of PCDDs and PCDFs on fly ash particles downstream of waste combustion.

  12. Thyrotoxic and dopaminergic effects of polychlorinated biphenyls

    SciTech Connect

    Ness, D.K.

    1994-01-01

    Perturbations in the developing nervous system have been associated with perinatal exposures to polychlorinated biphenyls (PCBs). To determine which PCBs accumulate in brain following perinatal exposure, Sprague-Dawley rats were exposed by gavage to Aroclor 1242 (4 or 16 mg/kg/day) during days 10-16 of gestation. At weaning (day 21), analysis of pup brain (frontal cortex, hippocampus, and caudate putamen) by gas chromatography revealed ten peaks representing 10-14 congeners in PCB-exposed animals. Brain PCB concentrations were greatest in high-dose pups for all congeners except for 2,4,4[prime]-trichlorobiphenyl (PCB 28) which had a higher concentration in the low-dose group. Congeners differed significantly in their degree of bioaccumulation, but no significant differences among brain regions were found. A lack of regionalization of PCB residues in the brain was also demonstrated by autoradiography in weanling rats treated iv with [[sup 14]C]-3,3[prime],4,4[prime]-tetrachlorobiphenyl or [[sup 14]C]-2,2[prime],4,4[prime]-tetrachlorobiphenyl. Time-mated Sprague-Dawley rats were exposed on days 10-16 of gestation to three environmentally-relevant PCBs: 2,4,4[prime]-trichlorobiphenyl (PCB 28), 8 or 32 mg/kg/day; 2,3[prime],4,4[prime],5-pentachlorobiphenyl (PCB 118), 4 or 16 mg/kg/day; or 2,2[prime],4,4[prime],5,5[prime]-hexachlorobiphenyl (PCB 153), 16 or 64 mg/kg/day. At weaning, serum total thyroxin, but not triiodothyronine, was markedly depressed in pups exposed perinatally to PCB 118 or 153; and thyroid glands from PCB 118-treated pups revealed histologic changes suggestive of sustained TSH stimulation. No significant PCB-induced changes were detected in the activity of the rate limiting enzyme in the synthesis of catecholamines, tyrosine hydroxylase, in the caudate putamen at weaning or in adulthood. Likewise no significant changes were detected in dopamine receptor (D1 and D2) concentrations in several regions in the mesocortical and nigrostriatal pathways.

  13. Occupational exposure to polychlorinated dioxins, polychlorinated furans, polychlorinated biphenyls, and biphenylenes after an electrical panel and transformer accident in an office building in Binghamton, NY.

    PubMed Central

    Schecter, A; Tiernan, T

    1985-01-01

    A polychlorinated biphenyl (PCB) and tri- and tetrachlorinated benzene-containing electrical transformer was involved in an explosion and fire in a modern office building in Binghamton, New York, on February 5, 1981. Because of an unusual system of air shafts the entire building and adjacent garage became contaminated with toxic chemicals. Polychlorinated dioxins, furans, and biphenylenes were formed as pyrolytic by-products. Before the extent of the chemical contamination was appreciated workers were exposed to these chemicals. Four years after the explosion and after the expenditure of over $22 million for cleaning and other expenses, the building remains closed. Images FIGURE 1. FIGURE 2. FIGURE 3. FIGURE 4. FIGURE 5. FIGURE 6. FIGURE 7. FIGURE 8. FIGURE 9. FIGURE 10. PMID:3928358

  14. INTRAUTERINE EXPOSURE OF HUMANS TO PCBS (POLYCHLORINATED BIPHENYLS): NEWBORN EFFECTS

    EPA Science Inventory

    The effect of low-level chronic exposure to polychlorinated biphenyls (PCBs) from consumption of Lake Michigan fish was assessed in pregnant women and their newborn offspring. Low levels of PCBs remain in the human body for some time, and caused, in this sample, decreases in birt...

  15. 77 FR 54863 - Polychlorinated Biphenyls (PCBs): Revisions to Manifesting Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-06

    ...The Environmental Protection Agency (``EPA'' or ``the Agency'') is issuing this proposed rule to update and clarify several sections of the Polychlorinated Biphenyl (PCB) regulations associated with the manifesting requirements, which uses the Resource Conservation and Recovery Act (RCRA) Uniform Hazardous Waste Manifest, under the Toxic Substances Control Act (TSCA). Today's changes are to......

  16. Exposure to Polychlorinated Biphenyls (PCBs): Implications for School Psychologists

    ERIC Educational Resources Information Center

    Cook-Cottone, Catherine

    2004-01-01

    Pediatric exposure to polychlorinated biphynels (PCBs) is a national health concern with significant implications for school psychologists. According to the healthcare collaboration model, the school psychologist plays a key role in the provision of services to children affected by environmental teratogens. To effectively function as healthcare…

  17. HEALTH ASSESSMENT DOCUMENT FOR POLYCHLORINATED DIBENZO-P-DIOXINS (1985)

    EPA Science Inventory

    The health assessment document on polychlorinated dibenzo-p-dioxins discusses multimedia environmental issues pertaining to the most toxic chlorinated dioxins, namely, 2,3,7,8-tetrachloro-; 1,2,3,7,8-pentachloro-; 1,2,3,6,7,8-hexachloro-; and 1,2,3,7,8,9-hexachlorodibenzo-p-dioxi...

  18. DEVELOPMENTAL NEUROTOXICOLOGY OF POLYCHLORINATED BIPHENYLS AND RELATED COMPOUNDS

    EPA Science Inventory

    Polychlorinated biphenyls are stable, lipophilic industrial compounds that are present in residue levels in human tissue, wildlife and freshwater sediment. hey are toxic and are known to pass the placenta and intoxicate the fetus. wo large outbreaks of poisoning have occurred in ...

  19. FIBER OPTIC FLUOROIMMUNOSENSOR FOR THE DETECTION OF POLYCHLORINATED BIPHENYLS

    EPA Science Inventory

    There currently exists a critical and growing need for cost-effective, real-time, and in situ methods for detection of environmental pollutants such as polychlorinated biphenyls (PCBs). erein reported is a evanescent wave Fluoroimmunosensor for measurement of PCBS. 2,4-5-Trichlor...

  20. Polychlorinated Biphenyls: In situ Bioremediation from the Environment

    EPA Science Inventory

    Polychlorinated biphenyls (PCBs) are a group of hydrophobic and stable organic compounds consisting of 209 possible congeners. Because of their unique physico-chemical properties, PCBs were used in a wide range of industrial applications. The properties that made PCBs useful in i...

  1. Polychlorinated Biphenyl Sources, Emissions, and Environmental Levels in School Buildings

    EPA Science Inventory

    Building materials and components containing polychlorinated biphenyls (PCBs) were used in some U.S. school buildings until the late 1970s and may be present today. PCB emission rates from caulk and fluorescent light ballasts were measured in laboratory chambers. PCB concentrat...

  2. POLYCHLORINATED BIPHENYLS IN PRECIPITATION IN THE LAKE MICHIGAN BASIN

    EPA Science Inventory

    Rainfall samples were collected in Chicago, Illinois, and on Beaver Island, Michigan, and analyzed for polychlorinated biphenyls (PCBs). The precipitation weighted mean concentration of 35 samples of rain was 111 mg/l. (111 parts per trillion). This would result in the deposition...

  3. HALF-LIFE OF POLYCHLORINATED BIPHENYLS IN OCCUPATIONALLY EXPOSED WORKERS

    EPA Science Inventory

    In 1977 and 1985, serum polychlorinated biphenyl (PCB) concentrations were determined for 58 workers in a Bloomington, Indiana, factory that used PCBs in capacitor manufacture until 1977. ess chlorinated PCBs were quantitated as Aroclor 1242, and more highly chlorinated PCBs were...

  4. DIRECT ELECTROCHEMICAL IMMUNOSENSOR FOR POLYCHLORINATED BIPHENYLS. (R825323)

    EPA Science Inventory

    A direct electrochemical immunosensor has been developed for the determination of polychlorinated biphenyls (PCBs) in water. The assay is based on the measurement of the current due to the specific binding between PCB and anti-PCB antibody-immobilized conducting polymer matrix. T...

  5. 21 CFR 109.30 - Tolerances for polychlorinated biphenyls (PCB's).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 2 2014-04-01 2014-04-01 false Tolerances for polychlorinated biphenyls (PCB's). 109.30 Section 109.30 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION UNAVOIDABLE CONTAMINANTS IN FOOD FOR HUMAN CONSUMPTION...

  6. 21 CFR 109.30 - Tolerances for polychlorinated biphenyls (PCB's).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 2 2013-04-01 2013-04-01 false Tolerances for polychlorinated biphenyls (PCB's). 109.30 Section 109.30 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION UNAVOIDABLE CONTAMINANTS IN FOOD FOR HUMAN CONSUMPTION AND FOOD-PACKAGING MATERIAL Tolerances...

  7. Polychlorinated biphenyl sources, environmental levels, and exposures in school buildings

    EPA Science Inventory

    Background: Building materials and components containing polychlorinated biphenyls (PCBs) were used in some U.S. school buildings until the late 1970s and may be present today. There is limited information on source factors and occupant exposures. Methods: Analysis of PCBs in mat...

  8. catena-Poly[[bis­(dimethyl­ammonium) [cadmate(II)-bis­(μ-1,1′:4′,1′′-terphenyl-3,3′′-dicarboxyl­ato)

    PubMed Central

    Park, Sang-Wook; Gu, Ja-Min; Kim, Youngmee; Huh, Seong

    2011-01-01

    In the title compound, {(C2H8N)2[Cd(C20H12O4)2]·2C3H7NO}n, the CdII ion lies on a twofold rotation axis and is in a distorted octa­hedral CdO6 environment, defined by four O atoms of two μ2-coordinated 1,1′:4′,1′′-terphenyl-3,3′′-dicarboxyl­ate (DCT) ligands and two O atoms of two μ1-coordinated DCT ligands. Both types of DCT ligands act as bridging, forming a one-dimensional polymeric structure propagating parallel to [10]. PMID:21522589

  9. An IARC evaluation of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans as risk factors in human carcinogenesis.

    PubMed Central

    McGregor, D B; Partensky, C; Wilbourn, J; Rice, J M

    1998-01-01

    The International Agency for Research on Cancer (IARC) Monographs program reevaluated polychlorinated dibenzo-p-dioxins and evaluated polychlorinated dibenzofurans as possible carcinogenic hazards to humans in February 1997, using the most recent epidemiologic data on exposed human populations, experimental carcinogenicity bioassays in laboratory animals, and supporting evidence on relevant mechanisms of carcinogenesis. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) was evaluated as carcinogenic to humans (IARC group 1 classification) on the basis of limited evidence of carcinogenicity to humans derived from follow-up of workers who had been heavily exposed in industrial accidents and sufficient evidence of carcinogenicity in experimental animals. The evaluation also considered the following supporting evidence: TCDD is a multisite carcinogen in experimental animals and has been shown by several lines of evidence to act through a mechanism involving the aryl hydrocarbon receptor; this receptor is highly conserved in an evolutionary sense and functions the same way in humans as in experimental animals; tissue concentrations of TCDD are similar in heavily exposed human populations in which an increased overall cancer risk was observed and in exposed rats that developed tumors in carcinogenicity tests. Other polychlorinated dibenzo-p-dioxins, the nonchlorinated dibenzo-p-dioxin, and polychlorinated dibenzofurans were evaluated as not classifiable as to their carcinogenicity to humans (group 3). PMID:9599727

  10. Polychlorinated biphenyls (PCBs) in San Francisco Bay.

    PubMed

    Davis, J A; Hetzel, F; Oram, J J; McKee, L J

    2007-09-01

    San Francisco Bay is facing a legacy of polychlorinated biphenyls (PCBs) spread widely across the land surface of the watershed, mixed deep into the sediment of the Bay, and contaminating the Bay food web to a degree that poses health risks to humans and wildlife. In response to this persistent problem, water quality managers are establishing a PCB total maximum daily load (TMDL) and implementation plan to accelerate the recovery of the Bay from decades of PCB contamination. This article provides a review of progress made over the past 15 years in managing PCBs and understanding their sources, pathways, fate, and effects in the Bay, and highlights remaining information needs that should be addressed in the next 10 years. The phaseout of PCBs during the 1970s and the 1979 federal ban on sale and production led to gradual declines from the 1970s to the present. However, 25 years after the ban, PCB concentrations in some Bay sport fish today are still more than ten times higher than the threshold of concern for human health. Without further management action it appears that the general recovery of the Bay from PCB contamination will take many more decades. PCB concentrations in sport fish were, along with mercury, a primary cause of a consumption advisory for the Bay and the consequent classification of the Bay as an impaired water body. Several sources of information indicate that PCB concentrations in the Bay may also be high enough to adversely affect wildlife, including rare and endangered species. The greater than 90% reduction in food web contamination needed to meet the targets for protection of human health would likely also generally eliminate risks to wildlife. PCB contamination in the Bay is primarily associated with industrial areas along the shoreline and in local watersheds. Strong spatial gradients in PCB concentrations persist decades after the release of these chemicals to Bay Area waterways. Through the TMDL process, attention is being more sharply

  11. EVALUATION OF AN EPA (ENVIRONMENTAL PROTECTION AGENCY) HIGH-VOLUME AIR SAMPLER FOR POLYCHLORINATED DIBENZO-P-DIOXINS AND POLYCHLORINATED DIBENZOFURANS

    EPA Science Inventory

    A High-Volume air sampler was evaluated for collection of poly-chlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF). The sampler consists of a filter, polyurethane foam adsorbent cartridge, air pump, and environmental housing. The use of an alternative ad...

  12. Polychlorinated dibenzodioxins and polyschlorinated dibenzofurans in sewage sludges

    SciTech Connect

    Weerasinghe, N.C.A.; Gross, M.L.; Lisk, D.J.

    1985-01-01

    A municipal sewage sludge from Syracuse, New York and a largely domestic sludge from Sodus, New York were analyzed for polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) using combined gas chromatography and high resolution mass spectrometry (GC/HRMS). Concentrations in ppt of the following PCDDs were found in the Syracuse sludge: tetrachlorodibenzo-p-dioxins (TCDDs), 150, hexachlorodibenzo-p-dioxins (HxCDDs), 2100, heptachlorodibenzo-p-dioxins (HCDDs), 6300, octachlorodibenzo-p-dioxins (OCDDs), greater than 60,000. The following ppt concentrations were found in the Sodus sludge: TCDDs, 7200, HxCDDs, 300 HCDDs, 900, OCDDs 7500. The TCDD was a single but not the highly toxic 2,3,7,8-isomers. PCDFs were mostly nondetectable in the sludges. The toxicology and potential for environmental contamination by these compounds are discussed.

  13. Characterization and fate of polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in soils and sediments at the Portsmouth Gaseous Diffusion Plant, Ohio.

    PubMed

    Kruse, Natalie A; Bowman, Jennifer; Lopez, Dina; Migliore, Elizabeth; Jackson, Glen P

    2014-11-01

    The U.S. Department of Energy Portsmouth Gaseous Diffusion Plant is in the early stages of decommissioning and decontamination. During operations, the site drew a large amount of electric power and had multiple large switchyards on site. These are a source of polychlorinated biphenyls (PCB) contamination to both on-site and off-site streams. Some soil remediation has been completed in the main switchyard. During 2011 and 2012, fifteen sites were sampled at the surface (<10 cm) and subsurface (20-30 cm) to characterize the extent of PCB contamination, to identify weathering and migration of PCB contamination and to explore potential polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) contamination due to transformer fires and explosions in the 1950s and 1960s. Stagnant sites tended to exhibit more migration of contamination to deeper sediments than sites with fast-moving waters, and the highest concentrations were found at the bottom of a settling pond. A signature set of five dioxin-like PCBs were consistently found across the site with higher concentrations in carbon rich surface sediments. PCB concentrations had a significant inverse correlation with clay content, suggesting that PCBs did not bind to clays at this site. Remediation has reduced PCB concentrations throughout the site compared to levels found in previous studies and long-term upkeep of sediment lagoons is necessary to retain PCB and dioxin-rich sediments. The flow regimen, organic carbon and clay content play a very important role in the fate of PCBs in the environment at the surface as well as downward migration. PMID:25113188

  14. Polychlorinated Biphenyl Presence in the Columbia River Corridor

    SciTech Connect

    R. M. Hermann

    2007-09-06

    The U. S. Department of Energy (DOE) is required by Comprehensive Environmental Response, Compensation, and Liability Act of 1980 regulations to develop a conceptual understanding of potential contaminant releases from the Hanford Site based on an evaluation of existing data and known historical practices. Polychlorinated biphenyls (PCBs) are one environmental contaminant potentially released through leaks, spills, or disposal. This document presents a summary of selected relevant existing information, including environmental studies and Hanford Site analytical data.

  15. CORRECTIVE ACTION PLAN FOR CORRECTIVE ACTION UNIT 528: POLYCHLORINATED BIPHENYLS CONTAMINATION NEVADA TEST SITE, NEVADA

    SciTech Connect

    BECHTEL NEVADA

    2005-06-01

    Corrective Action Unit (CAU) 528: Polychlorinated Biphenyls Contamination is listed in Appendix III of the Federal Facility Agreement and Consent Order (FFACO, 1996) and is located in Area 25 of the Nevada Test Site. CAU 528 was created to address polychlorinated biphenyl (PCB) contamination identified during the CAU 262 corrective action investigation. CAU 528 consists of one Corrective Action Site (CAS): CAS 25-27-03, Polychlorinated Biphenyls Surface Contamination.

  16. Removal of polychlorinated biphenyls by desulfurization and emissions of polychlorinated biphenyls from sintering plants.

    PubMed

    Wang, Mengjing; Hou, Meifang; Zhao, Kai; Li, Haifeng; Han, Ying; Liao, Xiao; Chen, Xuebin; Liu, Wenbin

    2016-04-01

    The influence of desulfurization on polychlorinated biphenyls (PCBs) from sintering plants was investigated. The concentrations of dioxin-like (dl) PCBs, toxic equivalents (TEQs), indicator PCBs, and total tri- to deca-chlorinated PCB homolog groups (∑PCBs) in the flue gases at the desulfurization system inlets were 290-1906 pg m(-3) (2.4-18.8 pg World Health Organization (WHO) TEQ m(-3)), 420-2885 pg m(-3), and 6496-22,648 pg m(-3), respectively. Desulfurization reduced the values to 43.3-500 pg m(-3) (0.46-9.5 pg WHO-TEQ m(-3)), 183-587 pg m(-3), and 2383-11,639 pg m(-3), respectively. The removed PCBs were adsorbed by gypsum from the flue gas; the PCB concentration distributions at the inlets and outlets and in the gypsum samples were similar. The emission factors were 9.86 ng WHO-TEQ t(-1) for the flue gas and 8.37 ng WHO-TEQ t(-1) for gypsum. Desulfurization decreased the annual atmospheric PCB emissions from 48.6 to 30.7 g WHO-TEQ, and the estimated annual emissions in gypsum were 8.06 g WHO-TEQ. PCBs in the gypsum have not been effectively eliminated and will probably reenter the environment and in turn become a new source of PCB emission. The PCB concentrations in fly ashes from series-connected electrostatic precipitators clearly increased. PMID:26690582

  17. Degradation of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans by the white rot fungus Phanerochaete sordida YK-624.

    PubMed Central

    Takada, S; Nakamura, M; Matsueda, T; Kondo, R; Sakai, K

    1996-01-01

    A method for the degradation of dioxins by white rot fungi was developed. Degradation of a mixture of 10 kinds of tetra- to octachlorodibenzo-p-dioxins (polychlorinated dibenzo-p-dioxins [PCDDs]) and tetra- to octachlorodibenzofurans (polychlorinated dibenzofurans [PCDFs]), which were chlorinated at 2-, 3-, 7-, and 8-positions of the molecules, by the white rot fungus Phanerochaete sordida YK-624 was studied in a stationary low-nitrogen medium. The percent degradation values of PCDDs and PCDFs were approximately 40 (tetra-chloro-) to 76% (hexachloro-) and 45 (tetrachloro-) to 70% (hexachloro-), respectively. Metabolites of 2,3,7,8-tetra- and octaCDD formed by P. sordida YK-624 included 4,5-dichlorocatechol and tetrachlorocatechol, respectively. These results suggest that white rot fungus is able to substantially degrade both PCDDs and PCDFs. This is the first report of the degradation of highly chlorinated PCDDs and PCDFs by a microorganism. PMID:8953705

  18. Identification of polychlorinated dibenzo-p-dioxin, dibenzofuran, and coplanar polychlorinated biphenyl sources in Tokyo Bay, Japan.

    PubMed

    Yao, Yuan; Masunaga, Shigeki; Takada, Hideshige; Nakanishi, Junko

    2002-05-01

    A dated sediment core collected from Tokyo Bay, Japan, was used to assess the historical inputs of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and coplanar polychlorinated biphenyls (Co-PCBs) from multiple sources. The levels, patterns, and profiles of these compounds in the core were congener-specifically investigated, and the results show that the PCDD and PCDF (PCDD/F) and the Co-PCB inputs increased abruptly from the late 1950s and peaked during the period 1967 to 1972. From 1972 to 1981, the inputs decreased continuously and then generally leveled off. Using principal component analysis, two herbicides widely used in the past, pentachlorophenol (PCP) and chloronitrofen (CNP), as well as combustion processes were identified as the major dioxin sources in Tokyo Bay. The PCB formulations and combustion processes were estimated to be the major sources of Co-PCBs. Furthermore, multiple regression analysis was performed for dioxin-source apportioning, and it was found that the herbicides PCP and CNP have mainly contributed to the PCDD/F burdens since the late 1950s. This study suggests that herbicide-derived PCDD/Fs remaining in agricultural land will continue to run off and pollute the aquatic environment in Japan for a long time. PMID:12013146

  19. Dioxin-like polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans in seafood samples from Malaysia: estimated human intake and associated risks.

    PubMed

    Leong, Yin-Hui; Gan, Chee-Yuen; Majid, Mohamed Isa Abdul

    2014-07-01

    A total of 127 and 177 seafood samples from Malaysia were analyzed for polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs), respectively. The World Health Organization-toxic-equivalency quotients (WHO-TEQ) of PCDD/Fs varied from 0.13 to 1.03 pg TEQ g(-1), whereas dl-PCBs ranged from 0.33 to 1.32 pg TEQ g(-1). Based on food-consumption data from the global environment monitoring system-food contamination monitoring and assessment programme, calculated dietary exposures to PCDD/Fs and dl-PCBs from seafood for the general population in Malaysia were 0.042 and 0.098 pg TEQ kg(-1) body weight day(-1), respectively. These estimations were quite different from the values calculated using the Malaysian food-consumption statistics (average of 0.313 and 0.676 pg TEQ kg(-1) body weight day(-1) for PCDD/Fs and PCBs, respectively). However, both of the dietary exposure estimations were lower than the tolerable daily intake recommended by WHO. Thus, it is suggested that seafood from Malaysia does not pose a notable risk to the health of the average consumer. PMID:24651928

  20. EFFECT OF SULFUR DIOXIDE ON THE FORMATION MECHANISM OF POLYCHLORINATED DIBENZODIOXIN AND DIBENZOFURAN IN MUNICIPAL WASTE COMBUSTORS

    EPA Science Inventory

    The effect of sulfur dioxide on the formation mechanism of polychlorinated dibenzodioxin (PCDD) and polychlorinated dibenzofuran (PCDF) in the postcombustion, downstream region (500-300 °C) of a municipal waste combustor (MWC) was investigated. Laboratory experiments simulating t...

  1. Crystal structure of 2,2′′-bis­(2,7-di­chloro-9-hy­droxy-9H-fluoren-9-yl)-1,1′:4′,1′′-terphenyl tri­ethyl­amine trisolvate

    PubMed Central

    Klien, Henrik; Seichter, Wilhelm; Weber, Edwin

    2015-01-01

    In the title solvate, C44H26Cl4O2·3C6H15N, the asymmetric part of the unit cell comprises two halves of the diol mol­ecules, 2,2′′-bis­(2,7-di­chloro-9-hy­droxy-9H-fluoren-9-yl)-1,1′:4′,1′′-terphenyl, and three mol­ecules of tri­ethyl­amine, i. e. the diol mol­ecules are located on crystallographic symmetry centres. Two of the solvent mol­ecules are disordered over two positions [occupancy ratios of 0.567 (3):0.433 (3) and 0.503 (3):0.497 (3)]. In the diol mol­ecules, the outer rings of the 1,1′:4′,1′′-terphenyl elements are twisted with reference to their central arene ring and the mean planes of the fluorenyl moieties are inclined with respect to the terphenyl ring to which they are connected, the latter making dihedral angles of 82.05 (8) and 82.28 (8)°. The presence of two 9-fluoren-9-ol units attached at positions 2 and 2′′ of the terphenyl moiety induces a ‘folded’ geometry which is stabilized by intra­molecular C—H⋯O hydrogen bonds and π–π stacking inter­actions, the latter formed between the fluorenyl units and the central ring of the terphenyl unit [centroid–centroid distances = 3.559 (1) and 3.562 (1) Å]. The crystal is composed of 1:2 complex units, in which the solvent mol­ecules are associated with the diol mol­ecules via O—H⋯N hydrogen bonds, while the remaining solvent mol­ecule is linked to the host by a C—H⋯N hydrogen bond. The given pattern of inter­molecular inter­actions results in formation of chain structures extending along [010]. PMID:26870400

  2. MODELLING OF POLYCHLORINATED-DIOXIN AND -FURAN CONGENER PROFILES FROM MUNICIPAL WASTE COMBUSTION

    EPA Science Inventory

    The paper discusses a model, based on experimental data, that was developed to describe the profile of polychlorinated dibenzo-p-dioxin (PCDD) and polychlorinated dibenzofuran (PCDF) congeners formed in the duct region of a pilot-scale combustor simulating large-scale municipal w...

  3. SAMPLING AND ANALYSIS FOR POLYCHLORINATED DIBENZO-P-DIOXINS AND DIBENZOFURANS IN AMBIENT AIR

    EPA Science Inventory

    A short-term study for determination of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in ambient air in Green Bay, Wisconsin, has been completed. eneral Metals Works PS-1 air samplers equipped with particle filters and polyurethane foam (PUF)...

  4. POLYCHLORINATED DIBENZO-P-DIOXINS AND DIBENZOFURANS IN THE REMOTE NORTH ATLANTIC MARINE ATMOSPHERE (R825377)

    EPA Science Inventory

    We have developed a sampling strategy that allows us to determine
    femtogram/cubic meter concentrations of polychlorinated dibenzo-p-dioxins
    and polychlorinated dibenzofurans (PCDD/F) in remote marine atmospheres. Using
    this sampling strategy, a total of 37 a...

  5. ATMOSPHERIC TRANSPORT AND DEPOSITION OF POLYCHLORINATED DIBENZO-P-DIOXINS AND DIBENZOFURANS

    EPA Science Inventory

    Polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) are toxic compounds which are dispersed through the environment by atmospheric transport and deposition. It has been previously shown that there is a varying mixture of these compounds produced by c...

  6. PAPER FIBERS AS A CARBON SOURCE FOR THE DE NOVO FORMATION OF POLYCHLORINATED DIOXINS AND FURANS

    EPA Science Inventory

    Formation of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzefurans (PCDDs/Fs) from carbons that were produced from pyrolysis of paper fibers and from a wood charcoal was investigated experimentally. Fibers obtained from a filter paper were pyrolyzed at 300 and 800 d...

  7. Health and productivity of dairy cows fed polychlorinated biphenyls

    SciTech Connect

    Willett, L.B.; Liu, T.T.; Durst, H.I.; Smith, K.L.; Redman, D.R.

    1987-07-01

    Holstein cows were studied through a complete lactation, a nonlactating period, and 42 days of a subsequent lactation for overt and subtle responses to a commercial mixture of polychlorinated biphenyls. Dosed cows (n = 4) received consecutive 60-day periods of daily dosing with 10, 100, and 1000 mg of Aroclor 1254. Control cows (n = 6) received daily sham doses. The following were recorded: daily milk production, feed intake, and health observations; weekly body weight, temperature, heart and respiratory rates and rectal palpation; semi-monthly clinical chemistry determinations; and monthly milk fat, microbiological culture of quarter foremilk samples, and composite milk somatic cell counts. Mean daily milk production (22.4 +/- 1.1 vs 24.8 +/- 1.0 kg) and net energy of a complete lactation (1.46 +/- 0.05 vs 1.45 +/- 0.03 Mcal/kg dry matter intake) were not different (p = 0.85) for control and PCB-dosed cows. Milk production during the first 42 days of the subsequent lactation was also similar for control and dosed cows. Occurrences of injuries, dysfunctions, and general infections were not related to polychlorinated biphenyl exposure. Intramammary infections were detected for both lactations with 51 and 32 infections detected in microbiological cultures, respectively, for the control and dosed groups. Environmental pathogens were most frequently isolated from cases of clinically apparent mastitis. The majority of quarter infections detected were due to Corynebacterium bovis. Only one animal (dosed, necropsy revealed left oviduct obstructed) failed to conceive with three to six services required before conception for the other control and dosed cows. Exposure to polychlorinated biphenyls resulting in maximal residues in milk fat, near 100 micrograms/g, had no apparent effect on health and productivity.

  8. Polychlorinated biphenyls (PCBs) depress allogeneic natural cytotoxicity by earthworm coelomocytes

    SciTech Connect

    Suzuki, M.M.; Cooper, E.L.; Eyambe, G.S.; Goven, A.J.; Fitzpatrick, L.C.; Venables, B.J. |

    1995-10-01

    Coelomocytes of the earthworm Lumbricus terrestris caused significant spontaneous allogeneic cytotoxicity in a 24-h trypan blue assay, but not in an assay using lactate dehydrogenase (LDH) release. Allogeneic cytotoxicity assays using cells from worms exposed to polychlorinated biphenyls (PCBs) suggest that PCBs can suppress a natural killing (NK-like) reaction. The implications of this work are twofold: understanding the evolution of natural killing (NK-like) activity and providing preliminary information on how spontaneous killing, a component of cellular immunity, may be compromised by pollutants.

  9. Polychlorinated biphenyl (PCB) partitioning between adipose tissue and serum

    SciTech Connect

    Brown, J.F. Jr.; Lawton, R.W.

    1984-09-01

    It has been recently suggested that variabilities in the partitioning of chronically retained lipophilic xenobiotics between adipose tissue and serum may be relatable to variations in the lipid content of the serum. Here, the authors present theoretical considerations and experimental data showing that this is indeed the case for polychlorinated biphenyls (PCBs) in humans. At equilibrium, in the absence of active transport, any lipophilic substance must distribute itself among body tissues in such a way that its chemical activity and also its chemical potential are the same at all points. In order to verify the theoretical relationships, three sorts of data relating to serum PCB levels in a human population were examined.

  10. Degradation of polychlorinated biphenyls (PCBs) using palladized iron

    SciTech Connect

    West, O.R.; Liang, L.; Holden, W.L.

    1996-06-01

    Contamination from polychlorinated biphenyls (PCBs) is a persistent problem within the Department of Energy complex, as well as in numerous industrial sites around the US. To date, commercially available technologies for destroying these highly stable compounds involve degradation at elevated temperatures either through incineration or base-catalyzed dehalogenation at 300{degrees}C. Since the heating required with these processes substantially increases the costs for treatment of PCB-contaminated wastes, there is a need for finding an alternative approach where PCB can be degraded at ambient temperatures. This report describes the degradation of PCB`s utilizing the bimetallic substrate of iron/palladium.

  11. Construction of a bioluminescent reporter strain to detect polychlorinated biphenyls

    SciTech Connect

    Layton, A.C.; Muccini, M.; Ghosh, M.M.; Sayler, G.S.

    1998-12-01

    A bioluminescent reporter strain, Ralstonia eutropha ENV307 (pUTK60), was constructed for the detection of polychlorinated biphenyls by inserting the biphenyl promoter upstream of the bioluminescence genes. In the presence of a nonionic surfactant, which enhances the solubility of chlorinated biphenyls, bioluminescence was induced three- to fourfold over background by biphenyl, monochlorinated biphenyls, and Aroclor 1242. The minimum detection limits for these compounds ranged from 0.15 mg/liter for 4-chlorobiphenyl to 1.5 mg/liter for Aroclor 1242.

  12. Degradation of polychlorinated biphenyls using mesoporous iron-based spinels.

    PubMed

    Huang, Linyan; Su, Guijin; Zhang, Aiqian; Shi, Yali; Xia, Chaobo; Lu, Huijie; Li, Liewu; Liu, Sha; Zheng, Minghui

    2013-10-15

    A series of mesoporous iron-based spinel materials were synthesized to degrade polychlorinated biphenyls (PCBs), with CB-209 being used as a model compound. The materials were characterized by X-ray powder diffraction (XRD), pore structure analysis, and X-ray photoelectron spectroscopy (XPS). A comparison of the dechlorination efficiencies (DEs) of the materials revealed that NiFe2O4 had the highest DE, followed by Fe3O4. Newly produced polychlorinated biphenyls, chlorinated benzenes, hydroxyl species and organic acids were detected by gas chromatography-mass spectrometry, high performance liquid chromatography-mass spectrometry and ion chromatograph. Identification of the intermediate products indicates that three degradation pathways, hydrodechlorination, the breakage of CC bridge bond and oxidative reaction, accompanied by one combination reaction, are competitively occurring over the iron-based spinels. The relative amounts of produced three NoCB isomers were illustrated by the CCl BDEs of CB-209 at meta-, para- and ortho-positions, and their energy gap between HOMO and LUMO. The consumption of the reactive oxygen species caused by the transformation of Fe3O4 into Fe2O3 in the Fe3O4 reaction system, and the existence of the highly reactive O2(-) species in the NiFe2O4 reaction system, could provide a reason why the oxidation reaction was more favored over NiFe2O4 than Fe3O4. PMID:23974532

  13. Semipermeable membrane devices used to estimate bioconcentration of polychlorinated biphenyls

    USGS Publications Warehouse

    Chambers, D.B.

    1999-01-01

    Aquatic organisms passively accumulate hydrophobic organic compounds, such as polychlorinated biphenyls, even when ambient water concentrations of the contaminant are below analytical detection limits. However, contaminant concentrations in tissue samples are subject to an inherently high level of variability due to differences in species, life stage, and gender bioconcentration potentials. Semipermeable membrane devices (SPMDs) were used to sample Aroclor 1254, a mixture of readily bioconcentrated polychlorinated biphenyls (PCBs), in a contaminated wetland near Flat Top, WV. The devices consisted of triolein, a lipid found in fish, enclosed in a polyethylene membrane. SPMDs were deployed in the water column and in direct contact with wetland sediments along a previously identified concentration gradient of PCBs. The devices were retrieved after a 25-day exposure period. Analytes were recovered by dialyzing the devices in nanograde hexane. Hexane dialysates were condensed and analyzed by gas chromatography. All deployed devices sequestered quantifiable amounts of Aroclor 1254. Water-column SPMDs accumulated PCBs far in excess of ambient water concentrations. The devices contacting sediments accumulated PCBs at all sites, though accumulated concentrations did not exceed concentrations in sediment. Patterns of PCB concentration in the devices corresponded to the identified gradient at the site. Results from the water-column SPMDs were used to estimate the concentration of the dissolved, bioavailable fraction of PCBs present in the water column. These concentrations ranged from 0.01 to 0.09 ??g/L of bioavailable Aroclor 1254.

  14. Emission of Polychlorinated Naphthalenes during Thermal Related Processes

    NASA Astrophysics Data System (ADS)

    Liu, Guorui; Zheng, Minghui; Du, Bing; Liu, Wenbin; Zhang, Bing; Xiao, Ke

    2010-05-01

    Due to the structural similarity of polychlorinated naphthalenes (PCNs) to those of dioxins, PCNs exhibit toxicological properties similar to dioxins (Olivero-Verbel et al., 2004). Based on their high toxicity, persistence, bioaccumulation, and long-distance transmission, PCNs were also selected as a candidate POP for the UN-ECE (United Nations Economic Commission for Europe) POP protocol (Lerche et al., 2002). In addition, some studies suggested that PCNs contributed a greater proportion of the dioxin-like activity than polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) contributed in some locations (Kannan et al., 1998). However, the identification and quantitation for PCN sources are very scarce compared with PCDD/Fs. Understanding the emission levels and developing the emission inventory of PCNs is important for regulatory and source reduction purposes. In this study, several potential sources were preliminarily investigated for PCN release. Coking process (CP), iron ore sintering (IOS), and electric arc furnace steel making units (AF) were selected due to their huge activity level of industrial production in China. Municipal solid waste incineration (MSWI) and medical waste incineration (MWI) were also investigated because of the possible high concentration of PCNs in stack gas. Two plants were investigated for each thermal related process, except for MWI with one incinerator was investigated. The stack gas samples were collected by automatic isokinetic sampling system (Isostack Basic, TCR TECORA, Milan Italy). Isotope dilution high resolution gas chromatography coupled with high resolution mass spectrometry (HRGC/HRMS) technique was used for the identification and quantitation of PCN congeners. The concentrations of PCNs from the selected thermal processes were determined in this study. The average concentrations of total PCNs were 26 ng Nm-3 for CP, 65 ng Nm-3 for IOS, 720 ng Nm-3 for AF, 443 ng Nm-3 for MSWI, and

  15. Levels and spatial distribution of gaseous polychlorinated biphenyls and polychlorinated naphthalenes in the air over the northern South China Sea

    NASA Astrophysics Data System (ADS)

    Li, Qilu; Xu, Yue; Li, Jun; Pan, Xiaohui; Liu, Xiang; Zhang, Gan

    2012-09-01

    Monitoring marine persistent organic pollutants (POPs) is important because oceans play a significant role in the cycling of POPs. The South China Sea (SCS) is surrounded by developing countries in Southeast Asia which are centers of e-waste recycling and the ship dismantling industry. In this study, shipboard air samples collected over the SCS between September 6 and 22, 2005 were analyzed for polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs). The levels of ∑12PCBs ranged from 32.3 to 167 pg m-3, with a mean value of 98.4 ± 36.0 pg m-3. Tetra-CBs were the predominant congeners. The concentrations of ∑18PCNs ranged from N.D. to 26.0 pg m-3, with a mean value of 10.5 ± 7.16 pg m-3, and tri-CNs were predominant. The gaseous concentrations of PCBs and PCNs over the SCS were consistent with those over other seas and oceans. Compared with previous studies, it was found that the concentrations of PCBs exhibited an obviously declining trend. The measured PCB and PCN concentrations in the atmosphere over the SCS were influenced by their proximity to source regions and air mass origins. The highest gaseous PCB and PCN concentrations were found at sampling sites adjacent to the continental South China. E-waste recycling, ship dismantling and combustion in South China and some Southeast Asian countries might contribute PCBs and PCNs to the atmosphere of the SCS.

  16. Spatial distribution of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in soil around a municipal solid waste incinerator.

    PubMed

    Liu, Wenbin; Li, Haifeng; Tian, Zhenyu; Xie, Huiting; Li, Changliang

    2013-10-01

    Municipal solid waste incinerators (MSWIs) are usually considered to be important sources of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs). To examine the influence of PCDD/Fs emissions from a MSWI on the surrounding environment, 21 soil samples were collected from various sampling sites distributed at distances of 300-1,700 m away from the stack of a MSWI. International Toxic Equivalent (I-TEQ) concentrations ranged from 0.47 to 2.07 pg I-TEQ g(-1), with average and median concentrations of 1.08 and 1.05 pg I-TEQ g(-1), respectively. Comparison of the results presented herein with other worldwide studies suggested that the concentrations of PCDD/Fs in the ambient soil were relatively low, indicating a limited impact on the surrounding environment. The emission concentrations from the incinerator were the critical factor in generating an environmental impact on the surrounding environment. An exponential function was developed, indicating a slight decline in TEQs of PCDD/Fs with increasing distance from the MSWI stack. The ordinary kriging interpolation technique was selected to create a contour map, which intuitively showed that a limited surrounding area (≤1,000 m from the stack) was obviously influenced by the MSWI. PMID:23801339

  17. Analysis of polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins and dibenzofurans in particulate and oily films on impervious surfaces.

    PubMed

    Klees, Marcel; Hiester, Ernst; Schmidt, Torsten C

    2015-12-15

    During this study wipe sampling was applied to various impervious surfaces for the determination of polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDFs) area concentrations. To that end, a wipe sampling method based on solvent wetted cotton wipes was evaluated and transfer efficiencies of PCBs and PCDD/PCDFs in particulate films (PFs) and oily liquid films (OFs) during sampling were investigated. For PFs sufficient transfer efficiencies of low concentrated PCB and PCDD/PCDF congeners in 1g/m(2) spiking surrogate were achieved after the first wipe using n-hexane as wetting solvent. Transfer efficiencies for OFs were the highest in the first wipe if n-hexane or n-heptane were used rather than toluene. The spiking experiments of OFs showed a log-linear correlation between the number of wiping procedures and transfer efficiency which indicates that transfer efficiencies were constant in subsequent wipes. Furthermore, it was successfully demonstrated that pressurized liquid extraction is a suitable tool for the extraction of wipe samples. Finally, the feasibility of this wipe sampling method was demonstrated on various impervious surfaces of different origin, and concentration levels of PCBs and PCDD/PCDFs in wipe samples are discussed. Hereby, remarkably high ∑CB6 concentrations of up to 1400μg/m(2) (taken at a transformer recycling site) were detected. PMID:26318221

  18. Evaluation of the Spanish hot dip galvanising sector as a source of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans.

    PubMed

    Martínez, M Angeles; Sanz, Paloma; Ruiz, M Luisa; Fabrellas, Begoña; Abad, Esteban; Rivera, Josep

    2008-04-01

    A survey to estimate the polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) emissions of Spanish hot dip galvanising sector was carried out during 2002. This investigation is the first presenting Spanish experimental data related to this industrial sector. Three different matrices: flue gas, ash and filter dust were tested to quantify the PCDD/Fs generated during the galvanising process. The organic source of PCDD/F formation could be from the insufficient degreasing o from inhibitors or additives used in the pickling steps such as quinoline, isoquinoline, 8-methylquinoline or polyether phosphoric acid. Low levels PCDD/Fs were achieved in air emissions when air control devices are used. On the contrary, filter dusts are highly contaminated; indicating that the absence of air control devices would increase the risk of fugitive emissions. Homologue profiles and Principal Component Analysis demonstrate there are differences in the formation mechanisms in the bath zone (ashes) compared to the stack location (filter dusts and air emissions), related to the de novo synthesis and reaction time. The annual PCDD/F emission to the atmosphere for this sector during 2002 has been estimated in 0.023g I-TEQ. The emission factor of plants with air control devices has been calculated at 0.030microg I-TEQ/ton of galvanised steel. PMID:18083211

  19. Utilization of mixed ligands to construct diverse Ni(II)-coordination polymers based on terphenyl-2,2‧,4,4‧-tetracarboxylic acid and varied N-donor co-ligands

    NASA Astrophysics Data System (ADS)

    Wang, Chao; Zhao, Jun; Xia, Liang; Wu, Xue-Qian; Wang, Jian-Fang; Dong, Wen-Wen; Wu, Ya-Pan

    2016-06-01

    Three new coordination polymers, namely, {[Ni(H2L)(bix)(H2O)2]·2h2O}n (1), {[Ni(HL)(Hdpa)(H2O)2]·H2O}n (2), {[Ni(L)0.5(bpp)(H2O)]·H2O}n (3) (H4L=terphenyl-2,2‧,4,4‧-tetracarboxylic acid; bix=1,4-bis(imidazol-1-ylmethyl)benzene; dpa =4,4‧-dipyridylamine; bpp=1,3-bis(4-pyridyl)propane), based on rigid H4L ligand and different N-donor co-ligands, have been synthesized under hydrothermal conditions. Compound 1 features a 3D 4-connected 66-dia-type framework with H4L ligand adopts a μ2-bridging mode with two symmetry-related carboxylate groups in μ1-η1:η0 monodentate mode. Compound 2 displays a 1D [Ni(HL)(Hdpa)]n ribbon chains motif, in which the H4L ligand adopts a μ2-bridging mode with two carboxylate groups in μ1-η1:η1 and μ1-η1:η0 monodentate modes, while 3 possesses a (4,4)-connected 3D frameworks with bbf topology, with H4L ligand displays a μ4-bridging coordination mode. The H4L ligand displays not only different deprotonated forms but also diverse coordination modes and conformations. The structural diversities among 1-3 have been carefully discussed, and the roles of N-donor co-ligands in the self-assembly of coordination polymers have been well documented.

  20. Gas chromatographic separation of methoxylated polychlorinated biphenyl atropisomers

    PubMed Central

    Kania-Korwel, Izabela; Vyas, Sandhya M.; Song, Yang; Lehmler, Hans-Joachim

    2008-01-01

    Several polychlorinated biphenyls (PCBs) and their hydroxylated metabolites display axial chirality. Here we describe an enantioselective, gas chromatographic separation of methylated derivatives of hydroxylated (OH-)PCB atropisomers (MeO-PCB) using a chemically bonded β-cyclodextrin column (Chirasil-Dex). The atropisomers of several MeO-PCBs could be separated on this column with resolutions ranging from 0.42–0.87 under isothermal or temperature-programmed conditions. In addition, the enantiomeric fraction of OH-PCB 136 metabolites was determined in male and female rats treated with racemic PCB 136. The methylated derivatives of two OH-PCB 136 metabolites showed an enantiomeric enrichment in liver tissue, whereas PCB 136 itself was near racemic. PMID:18760792

  1. Polychlorinated biphenyls (PCBs) in transit system electrical equipment

    NASA Astrophysics Data System (ADS)

    1984-05-01

    The legislative history and current regulatory requirements concerning the continued use of PolyChlorinated Biphenyls PCBs in transit system electrical equipment are presented. The recent rule-making by the EPA is presented in summary form to aid the reader in following the chronology of requirements affecting the continued operation, servicing, marking, and disposal of transit system electrical equipment which contains PCB materials. Types of transit system electrical equipment regulated by the EPA are identified and future regulatory requirements concerning allowable PCB concentration levels of specific electrical equipment are outlined. Transit system procedures for the handling of electrical equipment containing PCBs are presented and recommendations to assist transit systems in eliminating PCBs from electrical equipment are provided.

  2. Dehalorespiration with Polychlorinated Biphenyls by an Anaerobic Ultramicrobacterium▿

    PubMed Central

    May, Harold D.; Miller, Greg S.; Kjellerup, Birthe V.; Sowers, Kevin R.

    2008-01-01

    Anaerobic microbial dechlorination is an important step in the detoxification and elimination of polychlorinated biphenyls (PCBs), but a microorganism capable of coupling its growth to PCB dechlorination has not been isolated. Here we describe the isolation from sediment of an ultramicrobacterium, strain DF-1, which is capable of dechlorinating PCBs containing double-flanked chlorines added as single congeners or as Aroclor 1260 in contaminated soil. The isolate requires Desulfovibrio spp. in coculture or cell extract for growth on hydrogen and PCB in mineral medium. This is the first microorganism in pure culture demonstrated to grow by dehalorespiration with PCBs and the first isolate shown to dechlorinate weathered commercial mixtures of PCBs in historically contaminated sediments. The ability of this isolate to grow on PCBs in contaminated sediments represents a significant breakthrough for the development of in situ treatment strategies for this class of persistent organic pollutants. PMID:18223104

  3. Polychlorinated biphenyl transport in the Hudson River, New York

    USGS Publications Warehouse

    Turk, John T.; Troutman, David E.

    1981-01-01

    Polychlorinated biphenyls (PCB's) have been entering the Hudson River estuary since 1951. Concentration and loading of PCB 's in the river below Waterford, N.Y., are controlled at present by resuspension of sediments containing these substances; therefore , until the amount of PCB 's in the sediments is significantly lowered, reduction of point-source PCB discharge from the present rate of 0.4 kilograms per day will produce no more than a 10% reduction in loading to the river. Potential concentrations of PCB 's in solution and suspension in the river can be predicted by a simple model for mixing and dilution. From a known range of PCB influent rates, total PCB loading to the Hudson River from above Waterford is shown to be between 2,000 and 12,000 kilograms per year. (USGS)

  4. [Analysis of polychlorinated biphenyls and organochlorine pesticides in pine needles].

    PubMed

    Kozul, Darija; Herceg Romanić, Snjezana

    2007-12-01

    This paper presents a review of methods for the analysis of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in pine needles. These compounds are lipophilic, they accumulate in the biotic and abiotic part of the environment in which they are persistent, and their use is forbidden or restricted due to harmful effects on human and animal health. Pine needles are convenient for monitoring the levels of organochlorine compounds in the air because they accumulate them in wax with which they are covered. However, the presence of many other compounds makes them complex for analysis. Analytical methods for determining organochlorine compounds in pine needles include sample collection, extraction of compounds with a suitable solvent, extract clean-up from unwanted compounds and qualitative and quantitative analysis. PCBs and OCPs are present in pine needles in traces, and every part of the analytical procedure has to be as efficient and selective as possible. PMID:18063531

  5. Polychlorinated biphenyl partitioning and bioaccumulation in Green Bay, Lake Michigan

    SciTech Connect

    Endicott, D.; Griesmer, D.; Kreis, R.; Mackelburg, L.

    1994-12-31

    The 1989--1990 Green Bay Mass Balance Study generated an extensive data set for polychlorinated biphenyl (PCB) congeners in water, sediment and biological matrices. The analytes included several mono-ortho substituted PCB congeners. From these data, ratios between dissolved, particulate, and biotic concentrations in the water column and sediment have been calculated. These ratios provide a basis for evaluating the distribution of hydrophobic organic chemicals in the aquatic ecosystem. The Mass Balance Study also supported development of mathematical models of PCB transport, fate, and food chain bioaccumulation in Green Bay. The models provide significant additional insight as to processes affecting the observed PCB distribution, including spatial-temporal variability, organic carbon sorbent dynamics, sediment-water column disequilibria, and kinetics of bioaccumulation.

  6. Polychlorinated biphenyls: persistent pollutants with immunological, neurological, and endocrinological consequences.

    PubMed

    Crinnion, Walter J

    2011-03-01

    Polychlorinated biphenyls (PCBs) are considered "persistent organic pollutants;" fat-soluble compounds that bioaccumulate in individuals and bio-magnify in the food chain. PCBs were the first industrial compounds to experience a worldwide ban on production because of their potent toxicity. These compounds are still present in our food supply (fish, dairy, hamburger, and poultry being the most contaminated) and our bodies. Once in the body, they can cause long-term problems, especially for those exposed in utero. PCB bioaccumulation can lead to reduced infection fighting ability, increased rates of autoimmunity, cognitive and behavioral problems, and hypothyroidism. Some research also links PCBs to increased rates of type 2 diabetes. Testing is currently available for some of the most damaging PCBs. The testing compares individual levels to national reference values and can be interpreted to determine current exposure. Dietary measures can be enacted that will reduce PCB half-lives in humans by increasing excretion. PMID:21438643

  7. Polychlorinated biphenyl accumulation in tree bark and wood growth rings

    SciTech Connect

    Meredith, M.L.; Hites, R.A.

    1987-07-01

    Polychlorinated biphenyls (PCBs) were found in the bark of black walnut and tulip poplar trees growing near a PCB-contaminated landfill. PCBs were also found in the bark of white oak trees growing 14 km away from the landfill. The concentration of individual congeners in the bark averaged 18 ppb at the landfill and 0.5 ppb at the other site. The PCB congeners were accumulated into the bark in proportion to their lipophilicity (as measured by octanol-water partition coefficients). The authors findings suggest that tree bark could be used for biomonitoring of lipophilic organic pollutants in the atmosphere. There is little evidence that PCBs are present in the wood of trees. The signal to blank ratios are always less than 3, and the relative concentrations between 20-year time intervals do not show trends that correlate with the known inputs of PCBs in Bloomington, IN. 2 tables.

  8. Determination of acute toxicity of polychlorinated biphenyls to photobactrium phosphoreum

    SciTech Connect

    Chu, S.; Xu, X.; He, Y.

    1997-02-01

    Polychlorinated biphenyls (PCBs) are a highly lipophilic group of global pollutants, consisting of 209 congeners. PCBs were discovered before the turn of the century and their usefulness for industry, because of their physical properties, was recognized early. The distribution of PCBs in the environment was not noticed until Jensen and his colleagues found PCBs in wildlife samples. Since then, investigations in many parts of the world have revealed the widespread distribution of PCBs in environmental samples and PCVs are persistent and accumulate in food webs. Thus, determination of toxicities of commercial PCB mixtures and PCB congeners are required. Toxicity tests using luminous bacteria have shown high correlation to traditional bioassays. This study compared the EC50 values of the commercial mixtures, PCB3 and PCB5, with those of Aroclor 1242 and Aroclor 1254. 12 refs., 2 tabs.

  9. Effects of polychlorinated biphenyls on development and reproduction.

    PubMed

    Faroon, O M; Keith, S; Jones, D; de Rosa, C

    2001-04-01

    As part of its mandate, the Agency for Toxic Substances and Disease Registry (ATSDR) prepares toxicological profiles on hazardous chemicals found at Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) National Priorities List (NPL) sites that have the greatest public health impact. These profiles comprehensively summarize toxicological and environmental information. This article, which constitutes the release of an important section of the Toxicological Profile for Polychlorinated Biphenyls (ATSDR 2000) into the scientific literature, focuses on the developmental and reproductive effects of this group of synthetic organic chemicals (PCBs) in humans and animals. Information on other health effects, toxicokinetics, mechanisms of toxicity, biomarkers, interactions, chemical and physical properties, potential for human exposure, and regulations and advisories is detailed in the profile. Interested readers are encouraged to consult the original toxicological profile for more information. Profiles can be requested from ATSDR's Information Center by telephone (1-888-42-ATSDR [1-888-422-8737] or E-mail: (atsdric@cdc.gov). PMID:12117298

  10. Developmental neurotoxicology of polychlorinated biphenyls and related compounds

    SciTech Connect

    Tilson, H.A.; Harry, G.J.

    1992-01-01

    Polychlorinated biphenyls are stable, lipophilic industrial compounds that are present in residue levels in human tissue, wildlife and freshwater sediment. They are toxic and are known to pass the placenta and intoxicate the fetus. Two large outbreaks of poisoning have occurred in Asia and women pregnant at or after the exposures had children who were developmentally impaired. Laboratory experiments in rhesus monkeys and rodents designed to assess neural or developmental neurotoxic effects show altered activity levels, impaired learning, and delayed ontogeny of reflexes. Children exposed transplacentally to PCBs in North America have been reported to display hypotonia and hyporeflexia at birth, delay in psychomotor development at 6 and 12 months of age and poorer visual recognition at 7 months. PCBs appear to be developmental neurotoxicants in both humans and animals and may pose a significant health risk, particularly to pregnant women and their offspring.

  11. (E)-3-(2-Chloro­phen­yl)-1-(4,4′′-difluoro-5′-meth­oxy-1,1′:3′,1′′-terphenyl-4′-yl)prop-2-en-1-one

    PubMed Central

    Samshuddin, S.; Narayana, Badiadka; Yathirajan, Hemmige S.; Betz, Richard; Gerber, Thomas; Hosten, Eric

    2012-01-01

    The title compound, C28H19ClF2O2, is a polysubstituted terphenyl derivative bearing a Michael system in which the C=C double bond has an E conformation. In the crystal, C—H⋯Cl and C—H⋯O contacts connect the mol­ecules into layers lying perpendicular to the a axis. The shortest inter­centroid distance between symmetry-related 4-fluoro­phenyl groups is 3.7547 (16) Å. PMID:22590402

  12. Phototransformation of polychlorinated aromatics in gas phase and on aerosol

    NASA Astrophysics Data System (ADS)

    Zhang, Xinzhong

    1999-12-01

    A number of polychlorinated aromatics have been shown to pose health risks even at very low concentration levels. However, routes of introduction of these toxic congeners into the environment remain unclear. It is speculated that some of the toxic congeners may evolve, in part, from transformation of other less toxic congeners. The most likely route for these transformations is photolysis during atmospheric transport. An investigation of this phenomenon was undertaken in this study, and phototransformation of selected polychlorinated aromatics, representing the compound of environmental concern, such as PCDDs, PCDFs and PCBs, in gas phase were examined. The study involved monitoring the effect of various atmospheres on phototransformation mechanism and kinetics. The experimental setup consisted of the photoreactor coupled to a vapor generator, a particle generator, an electrostatic classifier, and a particle counter. This arrangement permitted introduction of contaminants at known concentrations in vapor or aerosol form. The contaminants were irradiated for varied periods and the disappearance kinetics was studied as a function of irradiation time. The correlation between congeners and the photodegradation pathway was also investigated. The first order kinetic constants and the quantum yields were measured. The experimental results showed that the vapor phase phototransformation rates are affected by the atmospheric parameters, e.g., phototransformation rates are significantly enhanced in the presence of oxygen. In general, less chlorinated compounds decomposed faster than higher chlorinated ones. The reductive dechlorination was evidenced through the formation of products with less chlorine substitution. The presence of hydrogen donors significantly increased the yield of the reductive dechlorination products. The oxygen dominated the phototransformation rates by the mechanisms other than reductive dechlorination. The phototransformation rates of the PCDDs

  13. Content of polychlorinated dibenzo-p-dioxins, dibenzofurans and dioxin-like polychlorinated biphenyls in fish from Latvian lakes.

    PubMed

    Zacs, D; Bartkevics, V; Viksna, A

    2013-04-01

    Seventeen polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/PCDFs) of the highest priority as well as twelve dioxin-like polychlorinated biphenyls (dl-PCBs) were analyzed in the muscle tissues of the following freshwater fish species sampled from eleven Latvian freshwater lakes: perch (Perca flavescens), carp (Cyprinus carpio), eel (Anguilla rostrata), bream (Abramis brama), chub (Leuciscus cephalus), pike (Esox lucius), sheatfish (Silurus glanis) and roach (Rutilus). To analyze the selected persistent organic pollutants in fish matrices, an optimization of EPA-1613 and EPA-1668A clean-up procedures was carried out, followed by validation of the analytical procedure according to Commission Regulation (EC) No 1883/2006. The adopted analytical procedure was in compliance with requirements of the more recent Commission Regulation (EU) No 252/2012. Modifications of carbon column chromatography clean-up and separation steps were used for treatment of the fish samples. Other clean-up procedure stages were performed according to the methods EPA-1613 and EPA-1668A and involved gel permeation chromatography (GPC), as well as manual acidic silica and Florisil column chromatography for purification and fractionation of the samples. An isotope dilution method was used for the qualitative and quantitative determination of individual congeners. Analytes of interest were separated and detected using gas chromatography - high resolution mass spectrometry. The concentration of PCDD/PCDFs and dl-PCBs in freshwater fish and eel samples ranged from 0.05 to 8.0 pg WHO(1998)-PCDD/PCDF-PCB-TEQ g(-1) fresh weight. These levels are below the EU maximum permissible limits although calculation of the content of these compounds relative to the weight of fat shows contamination levels similar to those found in Baltic herring and sprats, that are known to be highly contaminated. A difference in congener pattern between the Baltic Sea fish and freshwater fish was detected

  14. PARTITIONING OF POLYCHLORINATED BIPHENYL CONGENERS IN SEAWATER OF NEW BEDFORD HARBOR, MASSACHUSETTS

    EPA Science Inventory

    The partitioning of polychlorinated biphenyls (PCBS) between particulate and dissolved phases of seawater was examined along a concentration gradient in New Bedford Harbor, MA. egression analysis was used to examine the relationship between the log of the partition coefficients (...

  15. Tenax-GC Extraction Technique for Residual Polychlorinated Biphenyl and Polyaromatic Hydrocarbon Analysis in Biodegradation Assays

    PubMed Central

    Shiaris, M. P.; Sherrill, T. W.; Sayler, G. S.

    1980-01-01

    A rapid Tenax-GC extraction technique has been evaluated for use in conjunction with aqueous biodegradation assays for polyaromatic hydrocarbons and polychlorinated biphenyls. The method was quantitatively efficient and reproducible for phenanthrene, but variable and not quantitative for Aroclor 1254 (polychlorinated biphenyls). Aqueous sample volumes and varying concentrations of organic matter influenced polychlorinated biphenyl and polyaromatic hydrocarbon extraction efficiency. Phenanthrene recovery was decreased by soil extract but unaffected by spent bacteriological culture medium. Both types of organic matter caused significant reduction of Aroclor 1254 recovery. Polyaromatic hydrocarbon and polychlorinated biphenyl biodegradation assays, performed with reservoir samples, supported the laboratory evaluation. The study demonstrated the utility of the Tenax-GC extraction technique for phenanthrene analysis in biodegradation assessment; however, Tenax-GC extraction was not appropriate for Aroclor 1254 biodegradation studies. PMID:16345486

  16. ACCUMULATION OF POLYCHLORINATED ORGANIC CONTAMINANTS FROM SEDIMENT BY THREE BENTHIC MARINE SPECIES

    EPA Science Inventory

    A laboratory experiment was conducted to measure the accumulation of selected polychlorinated compounds by marine benthos exposed to environmentally contaminated sediment. andworms (Nereis virens), clams (Macoma nasuta), and grass shrimp (Palaemonetes pugio) were exposed to sedim...

  17. 77 FR 74006 - Polychlorinated Biphenyls (PCBs); Recycling Plastics From Shredder Residue

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-12

    ... AGENCY Polychlorinated Biphenyls (PCBs); Recycling Plastics From Shredder Residue AGENCY: Environmental... plastic separated from shredder residue under the conditions described in the Voluntary Procedures for Recycling Plastics from Shredder Residue, relying principally on the regulatory provisions for excluded...

  18. 78 FR 20640 - Polychlorinated Biphenyls (PCBs); Recycling Plastics from Shredder Residue

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-05

    ... Residue (77 FR 74006). Additional background information on recycling activities that would be affected by... AGENCY Polychlorinated Biphenyls (PCBs); Recycling Plastics from Shredder Residue AGENCY: Environmental... will generally allow for the recycling of plastic separated from shredder residue under the...

  19. GUIDELINES FOR THE DISPOSAL OF PCBS (POLYCHLORINATED BIPHENYLS) AND PCB ITEMS BY THERMAL DESTRUCTION

    EPA Science Inventory

    The report is a resource and guidelines document to aid EPA Regional Offices in interpreting and applying polychlorinated biphenyl (PCB) regulations to the thermal destruction of PCBs. As background material, the report describes fundamental processes of combustion, thermal destr...

  20. DECHLORINATION OF POLYCHLORINATED BIPHENYLS IN SEDIMENT SLURRIES BY PALLADIUM MODIFIED ZEROVALENT IRON

    EPA Science Inventory

    Polychlorinated biphenyls (PCBs) are one group of persistent organic pollutants (POPs) of international concern because of global distribution, persistence, and toxicity. Removal of these compounds from the environment presents a very tough challenge because they are highly hydro...

  1. TECHNICAL/ECONOMIC ASSESSMENT OF SELECTED PCB (POLYCHLORINATED BIPHENYL) DECONTAMINATION PROCESSES

    EPA Science Inventory

    Eleven emerging alternative treatments for polychlorinated biphenyl (PCB) contaminated sediments have been compared and ranked using technical performance, status of development, test and evaluation data needs, and cost as factors. In ranking the processes, weights were assigned ...

  2. ONTOGENETIC ALTERATIONS IN MOLECULAR AND STRUCTURAL CORRELATES OF DENDRITIC GROWTH FOLLOWING DEVELOPMENTAL EXPOSURE TO POLYCHLORINATED BIPHENYLS.

    EPA Science Inventory

    This is the first report showing both molecular and structural changes in brain following developmental exposure to a neurotoxicant. It is known that perinatal exposure to a neurotoxicant, polychlorinated biphenyls (PCBs), is associated with decreased IQ scores, impaired learnin...

  3. EMISSIONS OF POLYCHLORINATED BIPHENYLS AS PRODUCTS OF INCOMPLETE COMBUSTION FROM INCINERATORS

    EPA Science Inventory

    The paper discusses emissions of polychlorinated biphenyls (PCBs) as products of incomplete combustion from incinerators. PCBs were used widely as industrial chemicals, particularly as additives in electrical transformer cooling oil. Growing evidence of PCBs' role as a persistent...

  4. ENANTIOMERIC COMPOSITION OF CHIRAL POLYCHLORINATED BIPHENYL ATROPISOMERS IN AQUATIC AND RIPARIAN BIOTA

    EPA Science Inventory

    The enantiomeric composition of polychlorinated biphenyl (PCB) atropisomers was measured in river and riparian biota (fish, bivalves, crayfish, water snakes, barn swallows) from selected sites throughout the United States by using chiral gas chromatography/mass spectrometry. Nonr...

  5. DETERMINATION OF POLYCHLORINATED BIPHENYLS USING MULTIPLE REGRESSION WITH OUTLIER DETECTION AND ELIMINATION

    EPA Science Inventory

    A method for the analysis of capillary column Polychlorinated biphenyl (PCB) data using regression analysis with outlier checking and elimination, COMSTAR, is presented and evaluated. his algorithm determines the best combination of the commercial PCB mixtures which best fits the...

  6. MEASUREMENT OF FUGITIVE ATMOSPHERIC EMISSIONS OF POLYCHLORINATED BIPHENYLS FROM HAZARDOUS WASTE LANDFILLS

    EPA Science Inventory

    Four landfills known to contain large quantities of polychlorinated biphenyls (PCBs) were monitored for atmospheric emissions: Three of these were uncontrolled and contained large numbers of electrical capacitors, many of which were scattered on the surface and leaking PCB askare...

  7. COMPARING POLYCHLORINATED BIPHENYLS IN FARM-RAISED AND WILD-CAUGHT CATFISH FROM SOUTHERN MISSISSIPPI

    EPA Science Inventory

    Polychlorinated biphenyls (PCBs) are among the most thermally stable organic chemicals known. This characteristic has historically made them useful in a wide array of applications including use in electrical transformers and capacitors, varnishes, waxes, synthetic resins, epoxy ...

  8. Activation of AhR-mediated toxicity pathway by emerging pollutants polychlorinated diphenyl sulfides

    EPA Science Inventory

    Polychlorinated diphenyl sulfides (PCDPSs) are a group of environmental pollutants for which limited toxicological information is available. This study tested the hypothesis that PCDPSs could activate the mammalian aryl hydrocarbon receptor (AhR) mediated toxicity pathways. Eight...

  9. MONITORING FOR POLYCHLORINATED BIPHENYL EMISSIONS FROM AN ELECTROLYTIC CAPACITOR DISPOSAL PROJECT

    EPA Science Inventory

    Three different air sampling methods were used simultaneously to monitor for PCB emissions arising from a pilot disposal project involving electrolytic capacitors. Analytical results indicated that the primary polychlorinated biphenyl material was Aroclor 1242, and that airborne ...

  10. METHODS FOR DETERMINING THE POLYCHLORINATED BIPHENYL EMISSIONS FROM INCINERATION AND CAPACITOR AND TRANSFORMER FILLING PLANTS

    EPA Science Inventory

    Described are methods to measure the polychlorinated biphenyl (PCB) emissions from the stacks of municipal waste, industrial waste, and sewage sludge incinerators and from capacitor and transformer filling plants. The PCB emissions from the incineration plants are collected by im...

  11. Determination of body burdens for polychlorinated dibenzo-'p'-dioxins (PCDDS) and polychlorinated dibenzofurans (PCDFS) in california residents. Final report

    SciTech Connect

    Stanley, J.S.; Bauer, K.M.; Turman, K.; Boggess, K.; Cramer, P.

    1989-10-26

    Determination of body burden levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs and PCDFs) in residents of California was conducted based on a stratified survey design. Stratification factors included two geographical locations (San Francisco and Los Angeles), three age groups (12 to 34, 35 to 49, and 50 plus years), and sex. A total of 57 adipose tissue specimens were collected across the 12 specific strata. Analysis for the specific 2,3,7,8-substituted isomers was achieved based on high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS). Detectable levels of PCDDs and PCDFs were measured in all samples with isomer patterns consistent with findings in other studies conducted within the United States, Canada, and Europe. A questionnaire focused on the lifestyles of participants in the program was conducted to determine residual and occupational information and possible exposure routes to PCDDs and PCDFs. The data base provides a reference for comparison in future human monitoring programs.

  12. Levels of polychlorinated dibenzodioxins and polychlorinated dibenzofurans in breast milk samples from three dioxin-contaminated hotspots of Vietnam.

    PubMed

    Manh, Ho Dung; Kido, Teruhiko; Tai, Pham The; Okamoto, Rie; Honma, Seijiro; Liang, Sun Xian; Anh, Le Thai; Maruzeni, Shoko; Nghi, Tran Ngoc; Nishijo, Muneko; Nakagawa, Hideaki; Nhu, Dang Duc; Van Tung, Dao; Hung, Nguyen Ngoc; Son, Le Ke

    2015-04-01

    We determined polychlorinated dibenzodioxin (PCDD) and polychlorinated dibenzofuran (PCDF) levels in breast milk of 143 primiparae living around the three most dioxin-contaminated areas of Vietnam. The women sampled lived in the vicinity of former U.S. air bases at Bien Hoa (n=51), Phu Cat (n=23), and Da Nang (n=69), which are known as dioxin hotspots. Breast milk samples from Bien Hoa City, where residents live very close to the air base, showed high levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), with 18% of the samples containing >5 pgTCDD/g lipid. However, Phu Cat residents lived far from the air base and their samples showed lower TCDD levels, with none containing >5 pgTCDD/g lipid. In Da Nang, TCDD levels in mothers from Thanh Khe (close to the air base, n=43) were significantly higher than those in mothers from Son Tra (far from the air base, n=26), but not other PCDD and PCDF (PCDD/F) congeners. Although TCDD levels in Bien Hoa were the highest among these hotspots, levels of other PCDD/F congeners as well as the geometric mean concentration of total PCDD/F level in Bien Hoa (9.3 pg toxic equivalents [TEQ]/g lipid) were significantly lower than the level observed in Phu Cat (14.1 pgTEQ/g lipid), Thanh Khe (14.3 pgTEQ/g lipid), and Son Tra (13.9 pgTEQ/g lipid). Our findings indicated that residents living close to former U.S. air bases were exposed to elevated levels of TCDD, but not of other PCDD/F congeners. PMID:25569577

  13. Serum polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans among people eating contaminated home-produced eggs and beef.

    PubMed Central

    Goldman, L R; Harnly, M; Flattery, J; Patterson, D G; Needham, L L

    2000-01-01

    We compared serum polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) among residents of two homes to levels among age- and sex-matched comparison subjects. The residents of the two homes consumed contaminated eggs and beef from animals raised at the homes. The animals had greater soil contact than those raised with conventional commercial husbandry practices. The comparison subjects were from a similar rural area, but did not consume home-produced beef and eggs. Serum levels of 2,3,7, 8-substituted tetra-, penta-, and hexaCDDs and penta-, hexa-, and heptaCDFs were increased between 2- and 6-fold in residents from one home; contaminated eggs and beef were consumed by residents for 2-15 years. Elevations were less for those in the other index home, where only home-produced eggs were consumed for 2 years; a 3-fold elevation of 1,2,3,7,8,9-hexaCDD as compared to controls was most apparent. Very strong bivariate correlations among all of the 2,3,7, 8 penta- and hexaCDDs/CDFs were observed. The elevations observed verify that PCDD/PCDF-contaminated food contributed to the body burden of these compounds. The blood levels among the highest exposed participants are generally higher than those observed in other studies of U.S. contaminated-fish consumers and higher than average adipose tissue levels observed in U.S. urban populations. There are sufficient animal toxicologic and human epidemiologic data to recommend that exposures be reduced. In the study area, pentachlorophenol and pentachlorophenol incineration sources have been identified, and the animal contamination and blood elevations probably reflect these sources. Soil reference values and site-specific risk assessments should include estimates of exposures to contamination in home-produced animal products. Such estimates can be verified with limited PCDD/PCDF sampling of animals and humans. Images Figure 1 Figure 2 PMID:10620519

  14. Emissions of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans from the open burning of household waste in barrels

    SciTech Connect

    Lemieux, P.M.; Lutes, C.C.; Abbott, J.A.; Aldous, K.M.

    2000-02-01

    Backyard burning of household waste in barrels is a common waste disposal practice for which pollutant emissions have not been well characterized. This study measured the emissions of several pollutants, including polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/PCDFs), from burning mixtures designed to simulate waste generated by a recycling and a nonrecycling family in a 208-L (55-gal) burn barrel at the EPA's Open Burning Test Facility. This paper focuses on the PCDD/PCDF emissions and discusses the factors influencing PCDD/PCDF formation for different test burns. Four test burns were made in which the amount of waste placed in the barrel varied from 6.4 to 13.6 kg and the amount actually burned varied from 46.6% to 68.1%. Emissions of total PCDDs/PCDFs ranged between 0.0046 and 0.48 mg/kg of waste burned. Emissions are also presented in terms of 2,3,7,8-TCDD toxic equivalents. Emissions of PCDDs/PCDFs appear to correlate with both copper and hydrochloric acid emissions. The results of this study indicate that backyard burning emits more PCDDs/PCDFs on a mass of refuse burned basis than various types of municipal waste combustors (MWCs). Comparison of burn barrel emissions to emissions from a hypothetical modern MWC equipped with high-efficiency flue gas cleaning technology indicates that about 2--40 households burning their trash daily in barrels can produce average PCDD/PCDF emissions comparable to a 182,000 kg/day (200 ton/day) MWC facility. This study provides important data on a potentially significant source of emissions of PCDDs/PCDFs.

  15. Polychlorinated naphthalenes and coplanar polychlorinated biphenyls in tissues of harbor seals (Phoca vitulina) from the northern Gulf of Alaska.

    PubMed

    Wang, Dongli; Atkinson, Shannon; Hoover-Miller, Anne; Li, Qing X

    2007-05-01

    Blubber, liver and kidney samples of harbor seals (Phoca vitulina) from the northern Gulf of Alaska were collected during 2000-2001 for the analysis of polychlorinated naphthalenes (PCNs) and coplanar polychlorinated biphenyls (CoplPCBs). On the lipid weight (lw) base, the total concentrations of PCNs (Sigma PCNs) ranged from 0.3 to 27 ng/g lw, and the total concentrations of CoplPCBs (Sigma CoplPCBs) were 3.6-546 ng/g lw in all the tissue samples. Di-ortho PCBs and mono-ortho PCBs were dominant followed by non-ortho PCBs and PCNs. Sigma Mono-ortho PCBs and Sigma di-ortho PCBs in nursing seals were apparently lower than those in male adult seals, but Sigma PCNs and Sigma non-ortho PCBs in female adults were not significantly different from those in male adults. Differences in PCNs and CoplPCBs congener profiles in female and male adult seals are apparently related to their chemical structure and properties, animal's developmental stages and physiological conditions. A large quantity of mono-ortho and di-ortho PCBs might be transferred to newborns from the nursing seals during lactation, while non-ortho PCBs and PCNs were relatively accumulative in the mother seals. Sigma PCNs and Sigma CoplPCBs in the harbor seals correlated with ages, gender, body weight and blubber thickness, but the blubber Sigma PCNs and Sigma CoplPCBs in Kodiak Island and Southern Alaska Peninsula (KIAP) did not significantly differ from those in Prince William Sound (PWS). In addition to the new PCB data, this first report on PCN contamination in Alaskan harbor seal tissues is useful for the wildlife and ecosystem management and human health protection. PMID:17223166

  16. Exposure of northern leopard frogs in the Green Bay ecosystem to polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans is measured by direct chemistry but not hepatic ethoxyresorufin-O-deethylase activity

    SciTech Connect

    Huang, Y.W.; Karasov, W.H.; Patnode, K.A.; Jefcoate, C.R.

    1999-10-01

    The authors measured concentrations of polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) in northern leopard frogs collected from the Green Bay ecosystem and explored the catalytic activity of hepatic cytochrome P450-associated monooxygenase (P450 enzyme) as a biomarker for exposure to aryl hydrocarbon receptor (AhR) agonists. The two hypotheses tested were PCH concentrations in northern leopard frogs would be positively correlated with sediment polychlorinated hydrocarbon (PCH) levels in wetland habitats along a contamination gradient and hepatic ethoxyresorufin-O-deethylase (EROD) activity of northern leopard frogs, which is presumably mediated by aryl hydrocarbon receptor (AhR), would be positively correlated with PCH concentrations in frog carcasses from different collection sites. In 1994 and 1995, frogs from seven sites along the lower Fox River and Green Bay, USA, were assayed for hepatic EROD activities and whole carcass concentrations of PCBs, PCDDs, and PCDFs. Tissue total PCB concentrations ranging from 3 to 154 ng/g were significantly correlated with sediment PCB levels. Only one PCDD and two PCDFs at concentrations of 6 to 8 pg/g were found in the frogs collected with frog body weight and was similar among sites except for Peter's Marsh. No significant correlation was found between EROD activity and carcass PCB concentration. This result was consistent with the fact that the frogs collected from the Green Bay ecosystem had relatively low PCB concentrations compared with what was required for induction in the laboratory.

  17. Open dumping site in Asian developing countries: a potential source of polychlorinated dibenz-p-dioxins and polychlorinated dibenzofurans.

    PubMed

    Nguyen, Hung Minh; Tu, Binh Minh; Watanabe, Mafumi; Kunisue, Tatsuya; Monirith, In; Tanabe, Shinsuke; Sakai, Shinichi; Subramanian, Annamalai; Sasikumar, Karuppian; Pham, Hung Viet; Bui, Cach Tuyen; Tana, Touch S; Prudente, Maricar S

    2003-04-15

    Open landfill dumping areas for municipal wastes in Asian developing countries have recently received particular attention with regard to environmental pollution problems. Because of the uncontrolled burning of solid wastes, elevated contamination by various toxic chemicals including dioxins and related compounds in these dumping sites has been anticipated. In this study, concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and coplanar polychlorinated biphenyls (PCBs) were determined in soils from dumping sites in the Philippines, Cambodia, India, and Vietnam. Residue concentrations of PCDD/Fs and coplanar PCBs in dumping site soils were apparently greater than those in soils collected in agricultural or urban areas far from dumping sites, suggesting that dumping sites are potential sources of PCDD/Fs and related compounds. Observed PCDD/F concentrations in soils from dumping sites in the Philippines and Cambodia were comparable or higher than those reported for dioxin-contaminated locations in the world (e.g., near the municipal waste incinerators and open landfill dumping sites). Homologue profiles of PCDD/Fs in dumping site soils from the Philippines and, to a lesser extent, from Cambodia and India reflected patterns of samples representing typical emissions, while profiles of agricultural or urban soils were similar to those of typical environmental sinks. This result suggests recent formation of PCDD/Fs in dumping site areas and that open dumping sites are a potential source of dioxins in Asian developing countries. Uncontrolled combustions of solid wastes by waste pickers, generation of methane gas, and low-temperature burning can be major factors for the formation of dioxins in dumping sites. Elevated fluxes of PCDD/Fs to soils in dumping sites were encountered in the Philippines, Cambodia, India, and Vietnam-Hanoi, and these levels were higher than those reported for other countries. Considerable loading rates

  18. Functional MRI approach to developmental methylmercury and polychlorinated biphenyl neurotoxicity.

    PubMed

    White, Roberta F; Palumbo, Carole L; Yurgelun-Todd, Deborah A; Heaton, Kristin J; Weihe, Pal; Debes, Frodi; Grandjean, Philippe

    2011-12-01

    Prenatal and early childhood exposure to methylmercury (MeHg) or polychlorinated biphenyls (PCBs) are associated with deficits in cognitive, sensory, motor and other functions measured by neurobehavioral tests. The main objective of this pilot study was to determine whether functional magnetic resonance imaging (fMRI) is effective for visualization of brain function alterations related to neurobehavior in subjects with high prenatal exposure to the two neurotoxicants, MeHg and PCBs. Twelve adolescents (all boys) from a Faroese birth cohort assembled in 1986-1987 were recruited based on their prenatal exposures to MeHg and PCB. All underwent fMRI scanning during behavioral tasks at age 15 years. Subjects with high mixed exposure to MeHg and PCBs were compared to those with low mixed exposure on fMRI photic stimulation and a motor task. Boys with low mixed exposures showed patterns of fMRI activation during visual and motor tasks that are typical of normal control subjects. However, those with high exposures showed activation in more areas of the brain and different and wider patterns of activation than the low mixed exposure group. The brain activation patterns observed in association with increased exposures to MeHg and PCBs are meaningful in regard to the known neurotoxicity of these substances. This methodology therefore has potential utility in visualizing structural neural system determinants of exposure-induced neurobehavioral dysfunction. PMID:21545807

  19. Environmental contamination of ready meals by polychlorinated biphenyls (PCBs).

    PubMed

    Adenugba, Adeola A; McMartin, Dena W; Beck, Angus

    2012-01-01

    The level of polychlorinated biphenyls (PCBs) contamination in ready meals was investigated to determine exposure compared to other foodstuffs. Chilled ready meals from nine categories (ambient, Chinese, Indian, Traditional UK, Italian, American Tex-Mex, Vegetarian and Organic), and three samples within each category were Soxhlet extracted in triplicate with hexane for 24 h, followed by a clean-up on deactivated silica gel. The cleaned extracts were concentrated to 1 ml under N(2) gas and analyzed on gas chromatography mass spectrometry (GC-MS) for 7 target PCBs (congeners 28, 52, 101, 118, 153, 138, and 180). Individual congener concentrations ranged from non-detectable to 0.40 ng g(-1) (wet weight). The cumulative concentration of all congeners (ΣPCBs) ranged between 0.20 and 1.00 ng g(-1) (wet weight). These values translate into exposure levels of less than 1 μg kg(-1)day(-1) for reference men and women of 70 and 57 kg, respectively. This preliminary study demonstrates that ready meals, like many other foods, are contaminated by PCBs and may represent an important route of human exposure given contemporary changes in consumer food choice. Even though low levels of contamination were observed, long-term exposure for population groups consuming a high volume of ready meals may have cause for concern regarding chronic health risks. PMID:22934994

  20. Reproduction success of American kestrels exposed to dietary polychlorinated biphenyls.

    PubMed

    Fernie, K J; Smits, J E; Bortolotti, G R; Bird, D M

    2001-04-01

    While reproduction of wild birds is adversely affected by multiple environmental contaminants, we determined that polychlorinated biphenyls (PCBs) alone alter reproduction. Captive American kestrels (Falco sparverius), fed PCB-spiked (Aroclor 1248:1254:1260) food (7 mg/kg body weight/d) prior to and during the first breeding season only (100 d) laid eggs with environmentally relevant levels of total PCBs (34.0 microg/g whole egg wet wt vs 0 microg/g for controls). Reproduction changed during, not after, PCB exposure in this two-year study. The PCB-exposed pairs laid smaller clutches later in the season and laid more totally infertile clutches. Hatching success was reduced in PCB-exposed pairs, and 50% of PCB nestlings died within 3 d of hatching. Nearly 60% of PCB-exposed pairs with hatchlings failed to produce fledglings. Higher levels of total PCB residues and congeners were associated with later clutch initiation and fewer fertile eggs, hatchlings, and fledglings. We suggest that nonpersistent PCB congeners have a greater influence on reproduction than do persistent congeners. PMID:11345453

  1. Preconception maternal polychlorinated biphenyl concentrations and the secondary sex ratio

    SciTech Connect

    Taylor, Kira C.; Jackson, Leila W.; Lynch, Courtney D.; Kostyniak, Paul J.; Buck Louis, Germaine M. . E-mail: louisg@mail.nih.gov

    2007-01-15

    The secondary sex ratio is the ratio of male to female live births and historically has ranged from 102 to 106 males to 100 females. Temporal declines have been reported in many countries prompting authors to hypothesize an environmental etiology. Blood specimens were obtained from 99 women aged 24-34 prior to attempting pregnancy and quantified for 76 polychlorinated biphenyl (PCB) congeners using dual column gas chromatography with electron capture detection. Women were prospectively followed until pregnancy or 12 cycles of trying. The odds of a male birth for three PCB groupings (total, estrogenic, anti-estrogenic) controlling for maternal characteristics were estimated using logistic regression. Among the 50 women with live births and PCB data, 26 female and 24 male infants were born (ratio 0.92). After adjusting for age and body mass index, odds of a male birth were elevated among women in the second (OR=1.29) and third (OR=1.48) tertiles of estrogenic PCBs; odds (OR=0.70) were reduced among women in the highest tertile of anti-estrogenic PCBs. All confidence intervals included one. The direction of the odds ratios in this preliminary study varied by PCB groupings, supporting the need to study specific PCB patterns when assessing environmental influences on the secondary sex ratio.

  2. Polychlorinated biphenyl residues in sandstorm depositions in Beijing, China.

    PubMed

    Fu, Shan; Yang, Zhong-Zhi; Li, Ke; Xu, Xiao-Bai

    2008-10-01

    Sandstorms, which distribute many particles, are a special atmospheric occurrence and are frequent in northern China. We conducted this study to determine, for the first time, the concentration of polychlorinated biphenyls (PCBs) in sandstorm depositions. We collected 13 samples from urban areas of Beijing, and we measured a total of 144 PCB congeners. Thirteen samples all contained PCB residues. The total PCB concentration ranged from 1.6 to 15.6ngg(-1) (median, 4.8ngg(-1), dry weight), with trichlorinated biphenyls as the predominant homologue (>50.4%). Furthermore, we observed increasing PCB contamination from northwest to east Beijing. We later explored possible factors affecting contamination of the sandstorm depositions, which revealed a significant correlation between SigmaPCBs and the minimum particle size of the sandstorm deposition samples. Principal-component analysis revealed that the major source of PCBs in Beijing may be potentially associated with the number-one commercial PCB through the long-range transmission. In previous results, PCBs were not a severe component of contamination in sandstorm depositions of Beijing. However, this study suggested that sandstorm deposition may be a potential source of exposure to PCBs for the residents of Beijing, China. PMID:18674798

  3. Polychlorinated Biphenyls in Residential Dust: Sources of Variability

    PubMed Central

    Whitehead, Todd P.; Brown, F. Reber; Metayer, Catherine; Park, June-Soo; Does, Monique; Dhaliwal, Joginder; Petreas, Myrto X.; Buffler, Patricia A.; Rappaport, Stephen M.

    2014-01-01

    We characterized the variability in concentrations of polychlorinated biphenyls (PCBs) measured in residential dust. Vacuum cleaner samples were collected from 289 homes in the California Childhood Leukemia Study during two sampling rounds from 2001 to 2010 and 15 PCBs were measured by high resolution gas chromatography–mass spectrometry. Median concentrations of the most abundant PCBs (i.e., PCBs 28, 52, 101, 105, 118, 138, 153, and 180) ranged from 1.0–5.8 ng per g of dust in the first sampling round and from 0.8–3.4 ng/g in the second sampling round. For each of these eight PCBs, we used a random-effects model to apportion total variation into regional variability (6–11%), intra-regional between-home variability (27–56%), within-home variability over time (18–52%), and within-sample variability (9–16%). In mixed-effects models, differences in PCB concentrations between homes were explained by home age, with older homes having higher PCB levels. Differences in PCB concentrations within homes were explained by decreasing time trends. Estimated half-lives ranged from 5–18 years, indicating that PCBs are removed very slowly from the indoor environment. Our findings suggest that it may be feasible to use residential dust for retrospective assessment of PCB exposures in studies of children’s health. PMID:24313682

  4. Temporal trends of polychlorinated biphenyls in precipitation in Beijing, China

    NASA Astrophysics Data System (ADS)

    Yang, Guosheng; Ma, Lingling; Xu, Diandou; Liu, Liyan; Jia, Hongliang; Chen, Yang; Zhang, Yongbao; Chai, Zhifang

    2012-09-01

    Temporal trend of polychlorinated biphenyls (PCBs) was determined in precipitation and monthly depositional fluxes were calculated in Beijing for the first time from February 2009 to March 2011. Total PCBs concentrations ranged from 7.00 to 993 ng L-1 in dissolved phase and from 1.00 to 133 ng L-1 in particulate phase, with a two orders of magnitude variation. Concentrations of PCBs were dominated by dissolved phase, which accounted for 82.5% of the total PCBs in precipitation, implying PCBs enrichment in rainwater due to efficient scavenging of highly contaminated gas phase and nonfilterable submicron particles which easily adsorbed organic contaminants in urban atmosphere. Highest concentrations of PCBs were measured in snow, which were about two times higher than those in rainwater, demonstrating more efficient scavenging of PCBs by snow. The sum of bi-, tri- and tetrachlorinated congeners accounted for 70.5% of total PCBs in precipitation, suggesting that PCBs mainly come from the historical usage of domestic PCB product, e.g., trichlorobiphenyl. PCBs concentrations in both dissolved and particulate phases showed slow rate of decline, with a half-life of 16.9 years in precipitation, suggesting that the atmospheric concentrations of PCBs were decreasing slowly in Beijing. The wet deposition flux of ∑PCBs ranged from 0.240 to 6.55 μg m-2 month-1 (mean: 1.41 μg m-2 month-1), indicating a relatively high level of PCBs contamination in Beijing atmosphere.

  5. A comprehensive approach to actual polychlorinated biphenyls environmental contamination.

    PubMed

    Risso, F; Magherini, A; Ottonelli, M; Magi, E; Lottici, S; Maggiolo, S; Garbarino, M; Narizzano, R

    2016-05-01

    Worldwide polychlorinated biphenyls (PCBs) pollution is due to complex mixtures with high number of congeners, making the determination of total PCBs in the environment an open challenge. Because the bulk of PCBs production was made of Aroclor mixtures, this analysis is usually faced by the empirical mixture identification via visual inspection of the chromatogram. However, the identification reliability is questionable, as patterns in real samples are strongly affected by the frequent occurrence of more than one mixture. Our approach is based on the determination of a limited number of congeners chosen to enable objective criteria for Aroclor identification, summing up the advantages of congener-specific analysis with the ones of total PCBs determination. A quantitative relationship is established between congeners and any single mixture, or mixtures combination, leading to the identification of the actual contamination composition. The approach, due to its generality, allows the use of different sets of congeners and any technical mixture, including the non-Aroclor ones. The results confirm that PCB environmental pollution in northern Italy is based on Aroclor. Our methodology represents an important tool to understand the source and fate of the PCBs contamination. PMID:26805927

  6. PCB (polychlorinated biphenyls) concentrations in Wilson Reservoir catfish, 1985

    SciTech Connect

    Dycus, D.L.; Lowery, D.R.

    1986-09-01

    TVA conducted a study during autumn 1984 to determine concentrations of a variety of contaminants in biota from Wilson and upper Pickwick Reservoirs. Several contaminants were detected, with polychlorinated biphenyls (PCB) levels in catfish from Wilson Reservoir of greatest interest. PCB concentrations in twenty-two of 45 catfish from Wilson equaled or exceeded the Food and Drug Administration (FDA) tolerance of 2.0 ..mu..g/g and the average of all 45 was 2.6 ..mu..g/g. Contamination was widespread and did not show any geographical relationship to an embayment on Wilson Reservoir (Fleet Hollow) known to have PCBs in the sediments. As a result of these findings, the Northwest Alabama Regional Health Department issued an official notice to retail markets in June 1985 to discontinue selling catfish from Wilson Reservoir. TVA initiated studies to determine if there were other areas on Wilson with PCB contaminated sediments or PCB discharges, and an annual catfish collection was started in autumn 1985 to determine the year-to-year trend in PCB levels. As a follow-up to earlier studies, analyses of catfish collected during autumn 1985 indicated substantial reductions in PCB concentrations. Only 4 of 36 catfish had PCB concentrations which equaled or exceeded 2.0 ..mu..g/g and the overall average was 1.0 ..mu..g/g. Statistical analyses indicated PCB concentrations decreased with increased distance from Fleet Hollow. Further monitoring is recommended for 2 more years.

  7. Health effects of low-level exposure to polychlorinated biphenyls

    SciTech Connect

    Stark, A.D.; Costas, K.; Chang, H.G.; Vallet, H.L.

    1986-10-01

    A polychlorinated biphenyl (PCB) spill resulting from a transformer explosion in Syracuse, New York, with no subsequent fire, provided an opportunity for the examination of the effects of low-level PCB exposure without the confounding presence of furans and dioxins. The incident provided 52 individuals exposed to PCB among building personnel, police, firemen, and public utility employees. Sixty-eight nonexposed were matched to the exposed group by sex, age, employer, and job description. Data were collected on the exposed relative to their activities at the spill site, their location, possible routes of exposure duration of exposure, and subsequent health effects. Exposed and nonexposed were interviewed for past medical history and relevant symptoms. Blood chemistries were studied inclusive of SGOT, SGPT, total protein, CBC, cholesterol, and triglyceride levels, as well as a fasting blood PCB level measurement. Six weeks after the spill, exposed and nonexposed were re-interviewed and had their blood work repeated except for the CBC and PCB levels. Exposed and nonexposed laboratory results were unremarkable. Some transient skin irritation believed to be associated with PCBs was noted. There were significant PCBs in blood level trends for occupation, age, duration of exposure, and level of alcohol consumption. Triglyceride level was highly correlated with PCB level. This relationship held when age and alcohol consumption were controlled for.

  8. Environmental determinants of polychlorinated biphenyl concentrations in residential carpet dust.

    PubMed

    DellaValle, Curt T; Wheeler, David C; Deziel, Nicole C; De Roos, Anneclaire J; Cerhan, James R; Cozen, Wendy; Severson, Richard K; Flory, Abigail R; Locke, Sarah J; Colt, Joanne S; Hartge, Patricia; Ward, Mary H

    2013-09-17

    Polychlorinated biphenyls (PCBs), banned in the United Sates in the late 1970s, are still found in indoor and outdoor environments. Little is known about the determinants of PCB levels in homes. We measured concentrations of five PCB congeners (105, 138, 153, 170, and 180) in carpet dust collected between 1998 and 2000 from 1187 homes in four sites: Detroit, Iowa, Los Angeles, and Seattle. Home characteristics, occupational history, and demographic information were obtained by interview. We used a geographic information system to geocode addresses and determine distances to the nearest major road, freight route, and railroad; percentage of developed land; number of industrial facilities within 2 km of residences; and population density. Ordinal logistic regression was used to estimate the associations between the covariates of interest and the odds of PCB detection in each site separately. Total PCB levels [all congeners < maximum practical quantitation limit (MPQL) vs at least one congener ≥ MPQL to < median concentration vs at least one congener > median concentration] were positively associated with either percentage of developed land [odds ratio (OR) range 1.01-1.04 for each percentage increase] or population density (OR 1.08 for every 1000/mi(2)) in each site. The number of industrial facilities within 2 km of a home was associated with PCB concentrations; however, facility type and direction of the association varied by site. Our findings suggest that outdoor sources of PCBs may be significant determinants of indoor concentrations. PMID:23952055

  9. Polychlorinated Biphenyls Water Pollution along the River Nile, Egypt

    PubMed Central

    Megahed, Ayman Mohamed; Dahshan, Hesham; Abd-El-Kader, Mahdy A.; Abd-Elall, Amr Mohamed Mohamed; Elbana, Mariam Hassan; Nabawy, Ehab; Mahmoud, Hend A.

    2015-01-01

    Ten polychlorinated biphenyl (PCB) congeners were determined in water samples collected along the River Nile using gas chromatography-electron capture detector (GC-ECD). PCB concentrations ranged from 14 to 20 μg/L, which were higher than those reported in previous studies, indicating serious PCB pollution in the River Nile. PCB congener profiles varied depending on the sampling sties. PCB-138 was the predominant congener accounting for more than 18% of total PCBs. The composition of PCB congeners in the water revealed that highly chlorinated PCB technical mixtures such as Aroclor 1254 was the main PCB production historically used in Egypt. An increasing trend in PCB levels from the upper stream to the Nile estuaries was observed. The calculated flux of PCBs indicated that 6.8 tons of PCBs is dumped into the Mediterranean Sea each year from the River Nile. The hazard quotients and carcinogenic risk caused by PCB pollution in the River Nile were above the acceptable level indicating that PCBs in the River Nile water pose adverse health effects for all age groups. Our findings revealed that PCBs possess a serious risk to the Egyptian population that depends mainly on the River Nile as a source of water. Thus, stricter legislation and regulatory controls should be applied to reduce the risk of PCBs in Egypt. PMID:26798844

  10. Polychlorinated biphenyls and their interaction with the environment

    SciTech Connect

    Dickerson, K.S.; Korte, N.E.

    1994-05-01

    This document is a review of the existing technical literature regarding the physical and biological properties of polychlorinated biphenyls (PCBs) and their interaction with the environment. It is intended to be used when evaluating PCB-contaminated soil and the effects of specific environmental conditions on PCB degradation. PCBs are a class of chlorinated aromatic compounds with 209 possible structural arrangements. The composition of PCBs in the environment changes over time due to various physiochemical and biological properties and processes: vapor pressure, solubility, octanol-water partitioning, adsorption, and biodegradation. As the number of chlorine atoms increases, both vapor pressure and water solubility decrease, while adsorption and the octanol-water partitioning coefficient increase. Dechlorination of PCBs occurs primarily through aerobic and anaerobic microbial degradation. Aerobic bacteria preferentially dechlorinate less-chlorinated PCBs, while anaerobic bacteria preferentially dechlorinate more highly chlorinated PCBs. The less-chlorinated PCB congeners are less persistent in the environment due to volatilization, solubility, and aerobic biodegradation, while the more-chlorinated PCBs are more persistent in the environment due to adsorption. The composition of an original PCB mixture in the environment can be expected to change due to a combination of processes described above. Any attempt to determine the source of PCBs or Aroclors identified in an environment sample must be approached with caution to avoid inaccurate conclusions.

  11. Reliability of the determinations of polychlorinated contaminants (biphenyls, dioxins, furans)

    SciTech Connect

    Horwitz, W.; Albert, R.

    1996-05-01

    Precision performance parameters from results of 34 interlaboratory performance studies of polychlorinated aromatic ring compounds (biphenyls, dioxins, and furans) (PCCs) have been recalculated by using the Internation Union of Pure and Applied Chemistry-1987 harmonized protocol. Most studies of 1052 test samples, 56 analytes, 19 matrixes, and 2 types of detectors (electron capture and mass spectrometers) provide among-laboratories relative standard deviations (RSD{sub R}s), that are considerably better than those predicted form the Horwitz equation at fractional concentrations of 10{sup {minus}6} down to 10{sup {minus}15}. The explanation suggested is that supplying common reference calibration solutions, as was done in many of these studies, does not reflect realistic operating conditions. Furthermore, the ability to repeat, discuss, and reassess aberrant reported values results in underestimating the true RSD{sub R}. The commonly reported problems of preparation of standard calibrating solutions, instability of the detections system, and failure to follow quality control instructions and good laboratory practices may be important sources of inter-laboratory variability in PCC determinations. 55 refs., 15 figs., 7 tabs.

  12. Polychlorinated biphenyl release from resuspended Hudson River sediment.

    PubMed

    Schneider, Abby R; Porter, Elka T; Baker, Joel E

    2007-02-15

    Three shear turbulence resuspension mesocosms (STORM tanks) were used to examine the release of polychlorinated biphenyls (PCBs) from resuspended Hudson River sediment. Twenty-two percent of the resuspended PCBs desorbed after 2 h, and 35% +/- 8% of PCBs were in the dissolved phase after apparent steady state was reached in 2 days. After the first resuspension event, the solids were allowed to settle and the quiescent time was varied to determine whether the labile pool of PCBs is recharged during sediment consolidation. The steady-state log Koc values for the third subsequent resuspension were higher than for the first event due to lower dissolved PCB concentrations; the particulate PCB concentrations were constant between events. With 1 day of consolidation between resuspension events, the dissolved concentration of all congeners decreased an average of 8% +/- 5% between subsequent resuspension events. With 4 days between events, only the dissolved pentachlorinated PCBs decreased significantly (p = 0.002), suggesting that the easily desorbable PCBs recharge when there is sufficient time between resuspension events. PMID:17593705

  13. Amine-enhanced photodegradation of polychlorinated biphenyls. Final report

    SciTech Connect

    Meuser, J.M.; Weimer, W.C.

    1982-07-01

    Uncontrolled releases of polychlorinated biphenyls (PCBs) from transformers and capacitors pose a significant environmental problem to the electric utility industry. This report describes a series of experiments whose objective was to demonstrate the practicality of using natural solar radiation in conjunction with the application of an amine for in situ degradation of PCBs in contaminated soil. The soil tested was clay from beneath a capacitor rack at a pacific northwest utility substation. While no degradation of the PCBs in soil was found after two weeks of sunlight exposure, further solution experiments indicate that degradation of PCBs does occur in the presence of an amine and simulated solar radiation. In hexane solutions containing 1 ppM Aroclor 1268 with 10 and 100 ppM ethylenediamine, 37% and 53% reductions in PCB concentration, respectively, were found after 70 h of solar simulator irradiation. These results suggest that the clay matrix or other soil components may have interfered with the photodegradation process. Investigations into the reaction mechanism, reaction products, optimum treatment parameters and appropriate matrices appear to be warranted. Successful development of this in situ technique could lead to major savings in mitigation efforts for contaminated soils and surfaces.

  14. Chiral Polychlorinated Biphenyl Transport, Metabolism and Distribution - A Review

    PubMed Central

    Lehmler, Hans-Joachim; Harrad, Stuart J.; Hühnerfuss, Heinrich; Kania-Korwel, Izabela; Lee, Cindy M.; Lu, Zhe; Wong, Charles S.

    2009-01-01

    Chirality can be exploited to gain insight into enantioselective fate processes that may otherwise remain undetected because only biological, but not physical and chemical transport and transformation processes in an achiral environment will change enantiomer compositions. This review provides an in-depth overview of the application of chirality to the study of chiral polychlorinated biphenyls (PCBs), an important group of legacy pollutants. Like other chiral compounds, individual PCB enantiomers may interact enantioselectively (or enantiospecifically) with chiral macromolecules, such as cytochrome P-450 enzymes or ryanodine receptors, leading to differences in their toxicological effects and the enantioselective formation of chiral biotransformation products. Species and congener-specific enantiomer enrichment has been demonstrated in environmental compartments, wildlife and mammals, including humans, typically due to a complex combination of biotransformation processes and uptake via the diet by passive diffusion. Changes in the enantiomer composition of chiral PCBs in the environment have been used to understand complex aerobic and anaerobic microbial transformation pathways, to delineate and quantify PCB sources and transport in the environment, to gain insight into the biotransformation of PCBs in aquatic food webs, and to investigate the enantioselective disposition of PCBs and their methylsulfonyl PCBs metabolites in rodents. Overall, changes in chiral signatures are powerful, but currently underutilized tools for studies of environmental and biological processes of PCBs. PMID:20384371

  15. Kinetics of biphenyl and polychlorinated biphenyl metabolism in soil

    SciTech Connect

    Focht, D.D.; Brunner, W.

    1985-10-01

    The metabolism of /sup 14/C-labeled PCBs (polychlorinated biphenyls), which comprised the Aroclor 1242 mixture, was greatly enhanced by the addition of biphenyl (BP) to soil. After 49 days, only 25 to 35% of the original PCBs remained in the soil, and 48 to 49% was converted to /sup 14/CO/sub 2/ (including soil carbonates) in treatment enriched with BP; by contrast, 92% of the PCBs remained and less than 2% was converted to /sup 14/CO/sub 2/ in the unenriched control. Although the mineralization of PCBs in soils inoculated with Acinetobacter strain P6 was not greater than that in uninoculated BP-enriched soils, the initial and maximum mineralization rates and mineralization of BP was consistent with kinetic models based upon linear-no growth and exponential growth; lower cell densities (< 10/sup 6//g) of BP-oxidizing bacteria gave a better fit for exponential growth, whereas the highest cell density (10/sup 9//g) gave a better fit for linear-no growth. The numbers of BP-oxidizing bacteria declined exponentially upon depletion of the substrate. Since the mineralization of the chlorinated cometabolites was brought about by microorganisms (comensals) other than BP oxidizers, /sup 14/CO/sub 2/ production could not be fit to either of the two growth models. However, /sup 14/CO/sub 2/ production from the highest-density inoculum could be fit to a first-order (no-growth) sequential-reaction series.

  16. Hydroxylated Polychlorinated Biphenyls in the Environment: Sources, Fate, and Toxicities

    PubMed Central

    Tehrani, Rouzbeh; Van Aken, Benoit

    2013-01-01

    Hydroxylated polychlorinated biphenyls (OH-PCBs) are produced in the environment by the oxidation of PCBs through a variety of mechanisms, including metabolic transformation in living organisms and abiotic reactions with hydroxyl radicals. As a consequence, OH-PCBs have been detected in a wide range of environmental samples, including animal tissues, water, and sediments. OH-PCBs have recently raised serious environmental concerns because they exert a variety of toxic effects at lower doses than the parent PCBs and they are disruptors of the endocrine system. Although evidence has accumulated about the widespread dispersion of OH-PCBs in various compartments of the ecosystem, little is currently known about their biodegradation and behavior in the environment. OH-PCBs are today increasingly considered as a new class of environmental contaminants that possess specific chemical, physical, and biological properties not shared with the parent PCBs. This article reviews recent findings regarding the sources, fate, and toxicities of OH-PCBs in the environment. PMID:23636595

  17. [Microbial anaerobic dechlorination of polychlorinated biphenyls in paddy soil slurry].

    PubMed

    Yang, Kai; Yao, Xiao-yan; Chen, Chen; Shen, Chao-feng; Qin, Zhi-hui; Huang, Rong-lang

    2015-10-01

    We studied the dechlorination process of Aroclor1260, a high-chlorinated polychlorinated biphenyls (PCBs) mixture in an anaerobic paddy soil slurry, and further analyzed the related microbial community structures. The Aroclor1260 was reduced up to 55.5% in the natural paddy soil slurry in 128 days, and the reduction percentage dropped to 46.9% after incoculating the paddy soil slurry with a PCBs-dechlorination enrichment culture. The dechlorination mainly occurred in congeners of pentachlorobiphenyl, hexachlorobiphenyl, and specially, the heptachlorobiphenyl, with pentachlorobiphenyl accumulated as dechlorination intermediate. Hydrogen gas produced from fermentation of organic matters was maintained at a lower partial pressure due to its consumption during the dechlorination process, so that the methanogens was suppressed as well. The microbial community structure was significantly different between natural and inoculated paddy soils. Introducing the PCBs-dechlorination enrichment culture changed the local microbial community by the competition between the exogenetic dchlorinators and the indigenous bacteria, overall decreasing the dechlorination activity. PMID:26995917

  18. Volatilization of extensively dechlorinated polychlorinated biphenyls from historically contaminated sediments

    SciTech Connect

    Bushart, S.P.; Bush, B.; Barnard, E.L.; Bott, A. |

    1998-10-01

    A study was conducted as a preliminary characterization of the ability of polychlorinated biphenyl (PCB)-contaminated sediments to volatilize PCBs into the air upon drying under conditions meant to be environmentally relevant. Sediments collected from the St. Lawrence River contained high levels of PCBs. The PCB contamination consisted of high levels of mainly ortho-substituted mono- and dichlorobiphenyls, suggesting that the original contamination had been transformed by microbial reductive dechlorination. These sediments lost 0.07 to 1.7% of their total PCB content to the air during a 24-h drying cycle. Sediments with varying amounts of overlying water lost significantly less PCB to the air within the first few cycles than native sediments with no overlying water. Losses due to PCB volatilization were well correlated to sediment PCB concentration and water loss but not to drying temperatures (4--43 C) within 24-h drying cycles. The PCB congeners representing >90% of those volatilized within the first 24 h of drying were those produced in the sediment samples as a result of microbial reductive dechlorination of the original PCB contamination. The presence of these congeners in volatilized air samples was positively confirmed by gas chromatography-mass spectrometry with Fourier transform infrared detection (FTIR). These results strongly suggest that significant amounts of mono-, di-, and trichlorobiphenyls may be volatilized from PCB-contaminated sediments at ambient environmental conditions and that this PCB volatilization may be enhanced by microbial reductive dechlorination.

  19. Continuous catalytic hydrodechlorination of polychlorinated biphenyls (PCBs) in transformer oil.

    PubMed

    Veriansyah, Bambang; Choi, Hye-Min; Lee, Youn-Woo; Kang, Jeong Won; Kim, Jae-Duck; Kim, Jaehoon

    2009-12-01

    Continuous catalytic hydrodechlorination of polychlorinated biphenyls (PCBs) in the presence of transformer oils was carried out in a fixed bed reactor using a 57.6 wt% Ni on silicon oxide-aluminum oxide (SiO(2)-Al(2)O(3)) catalyst. Reaction temperatures ranging 150-300 degrees C, PCBs concentrations ranging 50-200 ppm, and reaction times ranging 1-8 h were tested. At a higher reaction temperature or at a lower PCBs concentration, catalytic activity was higher and complete dechlorination of PCBs resulted even at long reaction time. Catalyst regeneration using hexane and 0.1 M sodium hydroxide (NaOH) was effective to restore the catalytic activity. Fresh, spent and regenerated catalysts were characterized by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis. XRD analysis revealed growth of Ni crystallite size of the spent and the regenerated catalysts. XPS analysis showed that a considerable amount of chlorine and carbon species were deposited on the surface of the spent catalyst, which may play a role in the catalysts deactivation. PMID:20183511

  20. An Efficient Approach to Sulfate Metabolites of Polychlorinated Biphenyls

    PubMed Central

    Li, Xueshu; Parkin, Sean; Duffel, Michael W.; Robertson, Larry W.; Lehmler, Hans-Joachim

    2009-01-01

    Polychlorinated biphenyls (PCBs), a major class of persistent organic pollutants, are metabolized to hydroxylated PCBs. Several hydroxylated PCBs are substrates of cytosolic phase II enzymes, such as phenol and hydroxysteroid (alcohol) sulfotransferases; however, the corresponding sulfation products have not been isolated and characterized. Here we describe a straightforward synthesis of a series of ten PCB sulfate monoesters from the corresponding hydroxylated PCBs. The hydroxylated PCBs were synthesized by coupling chlorinated benzene boronic acids with appropriate brominated (chloro-)anisoles, followed by demethylation with boron tribromide. The hydroxylated PCBs were sulfated with 2,2,2-trichloroethyl chlorosulfate using DMAP as base. Deprotection with zinc powder/ammonium formate yielded the ammonium salts of the desired PCB sulfate monoesters in good yields when the sulfated phenyl ring contained no or one chlorine substituent. However, no PCB sulfate monoesters were isolated when two chlorines were present ortho to the sulfated hydroxyl group. To aid with future quantitative structure activity relationship studies, the structures of two 2,2,2-trichloroethyl-protected PCB sulfates were verified by X-ray diffraction. PMID:19345419

  1. Prenatal Exposure to Polychlorinated Biphenyls: A Neuropsychologic Analysis

    PubMed Central

    Boucher, Olivier; Muckle, Gina; Bastien, Célyne H.

    2009-01-01

    Objectives A large body of literature documents the effects of prenatal exposure to polychlorinated biphenyls (PCBs) on cognitive development of children. Despite this fact, no integrative synthesis has been published yet to identify the cognitive functions that are particularly affected. Our aim is to review this literature in an attempt to identify the cognitive profile associated with prenatal PCB exposure. Data sources Studies were identified by searching the PubMed database for articles published before June 2008. We reviewed data from nine prospective longitudinal birth cohorts for different aspects of cognition. Data extraction Associations between indicators of prenatal PCB exposure and performance on cognitive tasks reported in the selected studies are summarized and classified as general cognitive abilities, verbal or visual–spatial skills, memory, attention, and executive functions. Data synthesis The most consistent effects observed across studies are impaired executive functioning related to increased prenatal PCB exposure. Negative effects on processing speed, verbal abilities, and visual recognition memory are also reported by most studies. Converging results from different cohort studies in which exposure arises from different sources make it unlikely that co-exposure with another associated contaminant is responsible for the observed effects. Conclusion Prenatal PCB exposure appears to be related to a relatively specific cognitive profile of impairments. Failure to assess functions that are specifically impaired may explain the absence of effects found in some studies. Our findings have implications in the selection of cognitive assessment methods in future studies. PMID:19165381

  2. Neutrophhil function after exposure to polychlorinated biphenyls in vitro

    SciTech Connect

    Ganey, P.E.; Denison, M.; Roth, R.A.; Robinson, J.P. )

    1993-10-01

    Polychlorinated biphenyls (PCBs) are known to be immunotoxic, yet the effects on neutrophil (PMN) function are not well characterized. We incubated PMNs isolated from rat peritoneum with a mixture of PCB congeners, Aroclor 1242, in the absence or presence of either phorbol myristate acetate (PMA) to stimulate generation of supoxide anion (O[sub 2]) or N-formyl-methionyl-leucyl-phenylalanine (fMLP) to induce degranulation (measured as release of [beta]-glucuronidase). Aroclor 1242 alone stimulated O[sub 2] production at a concentration of 10 [mu]g/ml. Significant cytotoxicity was not observed under these conditions. This concentration of Aroclor 1242 also increased O[sub 2] generation in PMNs activated with 20 ng PMA/ml. In the presence of a concentration of PMA (2 ng/ml) that by itself did not stimulate production of O[sub 2], 1 [mu]g Aroclor 1242/ml caused significant generation of O[sub 2], indicating synergy between Aroclor 1242 and PMA. Aroclor 1242 caused release of [beta]-glucuronidase from quiescent PMNs; however, in PMNs stimulated with fMLP to undergo degranulation, Aroclor 1242 inhibited release of [beta]-glucuronidase.

  3. Environmental determinants of polychlorinated biphenyl concentrations in residential carpet dust

    PubMed Central

    DellaValle, Curt T.; Wheeler, David C.; Deziel, Nicole C.; De Roos, Anneclaire J.; Cerhan, James R.; Cozen, Wendy; Severson, Richard K.; Flory, Abigail R.; Locke, Sarah J.; Colt, Joanne S.; Hartge, Patricia; Ward, Mary H.

    2014-01-01

    Polychlorinated biphenyls (PCBs), banned in the United Sates in the late 1970s, are still found in indoor and outdoor environments. Little is known about the determinants of PCB levels in homes. We measured concentrations of 5 PCB congeners (105, 138, 153, 170, 180) in carpet dust collected between 1998–2000 from 1,187 homes in four sites: Detroit, Iowa, Los Angeles, and Seattle. Home characteristics, occupational history, and demographic information were obtained by interview. We used a geographic information system to geocode addresses and determine distances to the nearest major road, freight route, and railroad, percentage of developed land, number of industrial facilities within 2 km of residences, and population density. Ordinal logistic regression was used to estimate the associations between the covariates of interest and the odds of PCB detection in each site separately. Total PCBs levels (all congeners < maximum practical quantitation limit [MPQL] vs. at least one congener ≥ MPQL to < median concentration vs. at least one congener >median concentration) were positively associated with either percentage of developed land (ORrange: 1.01-1.04 for each percentage increase) or population density (OR: 1.08 for every 1,000/mi2) in each site. The number of industrial facilities within 2 km of a home was associated with PCB concentrations; however, facility type and the direction of the association varied by site. Our findings suggest that outdoor sources of PCBs may be significant determinants of indoor concentrations. PMID:23952055

  4. Biomagnification of polychlorinated biphenyls through a riverine food web

    SciTech Connect

    Zaranko, D.T.; Kaushik, N.K.; Griffiths, R.W.

    1997-07-01

    From 1989 to 1993, biota collected from Pottersburg Creek, London, ON, Canada were analyzed for total polychlorinated biphenyls (PCBs) and lipids. Data were analyzed by analysis of covariance (ANCOVA) with lipid as the covariate, to investigate station, time, and trophic effects on PCB accumulation in aquatic organisms. All three variables were highly significant. PCB concentrations in biota decreased along the length of the creek away from the point source. PCB concentrations in biota collected in July 1993 were not significantly different from concentrations in biota collected in July 1990, suggesting that sources into the creek have not been alleviated. The relationship between PCBs and lipid for biota from Pottersburg Creek suggests that organisms accumulate PCBs relative to their position in the food web. Fish and leeches occupying the top of the food web accumulated more PCBs than organisms occupying a lower trophic position (crayfish and oligochaetes/chironomids), indicating that biomagnification through trophic transfer (i.e., the uptake of a chemical through ingestion) is the primary mechanism governing contaminant levels in biota and not bioconcentration (i.e, the uptake of a chemical from water).

  5. Polychlorinated biphenyls emission from a medical waste incinerator in China.

    PubMed

    Chen, Tong; Li, Xiaodong; Yan, Jianhua; Jin, Yuqi

    2009-12-30

    Detailed polychlorinated biphenyls (PCBs) congener patterns were determined in the flue gas from a medical waste incinerator (MWI) using high-resolution gas chromatograph coupled to high-resolution mass spectrometer (HRGC/HRMS). The total PCBs concentration of all homologues (mono- to deca-chlorinated homologues) in the flue gas ranged from 138.01 to 855.35 ng/Nm(3) and the WHO-TEQ value varied from 0.046 to 0.549 ng/Nm(3) under the different operating conditions. PCB-77 concentration was the highest among dioxin-like PCBs and PCB-126 contributed mostly to the WHO-TEQ. The ratios of dioxin-like PCBs in the total PCB concentrations in the flue gas varied between 11.7% and 26.0% (the average value is 18.7%). Three inhibitors, sulfur, urea, and ammonium sulfate were tested to investigate the capacity for preventing PCBs formation. The decomposition efficiency for total PCBs and PCBs TEQ ranged from 38% to 84% and 69% to 92% respectively. It was shown that urea mixed with ammonium sulfate and more activated carbon was proved to be the most effective inhibitor for PCBs formation. The removal efficiencies (REs) of the total PCBs concentration and PCBs TEQ by the bag filter under two conditions were 69% and 85%, and 86% and 94% respectively. PMID:19744782

  6. Polychlorinated Biphenyl (PCB) carcinogenicity with special emphasis on airborne PCBs

    PubMed Central

    Robertson, Larry W.; Ludewig, Gabriele

    2011-01-01

    Polychlorinated biphenyls (PCBs) are industrial chemicals used in various applications requiring chemical stabilityand have now become widely dispersed. Their characteristics of persistence, low water/higher lipid solubility, contribute to their ability to bioconcentrate and bioaccumulate. Traditionally PCBs have been regulated as food contaminants and the general population is primarily exposed by that route. PCBs in foodstuffs are generally higher chlorinated, resistant to metabolic breakdown, and elicit toxic changes that are thought to be predominantly receptor/parent PCB-driven. But for certain occupational exposures, and for those persons residing or working in contaminated buildings, and in large cities, an inhalation route of exposure may predominate. Airborne PCBs are, in contrast to foodborne PCBs, lower chlorinated, more volatile, and subject to metabolic attack. In this review, we have explored (geno-) toxic manifestations of PCBs typical of those found in air. Here metabolic conversion of the parent PCB to hydroxylated and other metabolic progeny appear to play a dominant role, especially in genotoxicity. We should be cognizant of the impact of exposures to airborne PCBs for those individuals who are occupationally exposed, for persons living near contaminated sites, for those who work or go to school in contaminated buildings, and especially cognizant of the young, the socio-economically disadvantaged and medically-underserved or nutritionally-deficient populations. PMID:21686028

  7. Polychlorinated biphenyls (PCBs) in bottom sediments: identification of sources.

    PubMed

    Wolska, Lidia; Mechlińska, Agata; Rogowska, Justyna; Namieśnik, Jacek

    2014-09-01

    Polychlorinated biphenyls (PCBs) can enter the environment from various sources. They are synthetic chemicals and as such are present in the environment mainly as mixtures containing various amounts of PCB congeners. It is therefore difficult to pinpoint the source of PCB emissions into the environment and the pathways along which they migrate there. The situation is different where locating the emission sources of polycyclic aromatic hydrocarbons (PAHs) is concerned. There is much information in the literature on the molecular markers that can be used to identify the sources of PAH emissions into the environment. Environmental samples like soil or bottom sediments are usually analysed for their contents of both groups of compounds. Therefore, with data on the origins of PAHs to hand, and seeking and comparing mutual correlations, one can attempt to define the probable sources of emission of PCBs. The purpose of this work was to identify the probable PCBs emission sources in bottom sediments using available data, that is polycyclic aromatic hydrocarbon diagnostic ratios. The numerical ratios of pairs of compounds such as fluoranthene/pyrene, phenanthrene/anthracene, fluoranthene/(fluoranthene+pyrene) and chrysene/benzo[a]anthracene are generally used as a tool for identifying and assessing pollution emission sources. PMID:24997912

  8. Inhalation of Polychlorinated Biphenyls (PCB) Produces Hyperactivity in Rats.

    PubMed

    Lombardo, John P; Berger, David F; Hunt, Anne; Carpenter, David O

    2015-01-01

    Attention deficit hyperactivity disorder (ADHD) is a serious behavioral syndrome seen in children, and more common in males than females. There is increasing evidence that prenatal and/or early life exposure to persistent organic pollutants (POP) such as polychlorinated biphenyls (PCB) is associated with increased risk of ADHD occurrence. While PCB exposure is usually attributed to ingestion of contaminated food, recent reports of elevated PCB concentrations in indoor air, especially in schools, raised concern regarding inhalation as an important route of exposure to PCB with consequent effects on neurobehavior. The effects of exposure to air contaminated with Aroclor 1248 or contaminated sediment (SED) from the St. Lawrence River were examined on operant behavior of male and female Sprague-Dawley rats. Data showed that relative to controls, vapor-phase inhalation of PCB, whether from blowing air over Aroclor 1248 or from blowing air over sediment contaminated with PCB, resulted in hyperactivity and impatience in rats, more pronounced in males than females. These results are consistent with the hypothesis that inhalation of PCB may contribute to behavioral abnormalities in children. PMID:26398098

  9. Sorption of polychlorinated biphenyls by north sea sediments

    NASA Astrophysics Data System (ADS)

    Booij, Kees; van der Meer, Jaap; Kwast, Diana; de Boer, Joost L.

    1997-05-01

    The sediment-water partition coefficients ( Kd) of 32 polychlorinated biphenyls (PCBs) and penta- and hexachloro benzene were determined for 37 spiked sediment samples from the southern North Sea, the German Bight and the Norwegian Channel. Organic-carbon contents for these sediments were in the range 0.02-2.4%. Log( Kd) values were in the range 1.4 to 5.3. The largest difference between the organic-carbon normalised partition coefficients ( Koc) for individual components amounted to a factor of 10. Koc values for coarse sediments were generally lower than values for fine sediments. The solids concentration effect was evaluated using the Non-Settling Particles model, the Solute Complexation model, the Implicit Adsorbate model, and the Particle Interaction model. The latter three models could be rejected on the basis of the experimental evidence. The validity of ordinary least-squares regression for estimating slope and intercept of log( Koc)-log( KKow) relations is discussed. Differences in sediment characteristics cause changes in the intercept of log( Koc)-log( Kow) relations, but not in the slope. KKoc values of PCB isomers are inversely related to the number of chlorine atoms in the ortho position relative to the inter-ring bond. The validity of the data for estimating field values of sorption coefficients is discussed.

  10. Functional MRI approach to developmental methylmercury and polychlorinated biphenyl neurotoxicity

    PubMed Central

    White, Roberta F.; Palumbo, Carole L.; Yurgelun-Todd, Deborah A.; Heaton, Kristin J.; Weihe, Pal; Debes, Frodi; Grandjean, Philippe

    2015-01-01

    Prenatal and early childhood exposure to methylmercury (MeHg) or polychlorinated biphenyls (PCBs) are associated with deficits in cognitive, sensory, motor and other functions measured by neurobehavioral tests. The main objective of this pilot study was to determine whether functional magnetic resonance imaging (fMRI) is effective for visualization of brain function alterations related to neurobehavior in subjects with high prenatal exposure to the two neurotoxicants, MeHg and PCBs. Twelve adolescents (all boys) from a Faroese birth cohort assembled in 1986–1987 were recruited based on their prenatal exposures to MeHg and PCB. All underwent fMRI scanning during behavioral tasks at age 15 years. Subjects with high mixed exposure to MeHg and PCBs were compared to those with low mixed exposure on fMRI photic stimulation and a motor task. Boys with low mixed exposures showed patterns of fMRI activation during visual and motor tasks that are typical of normal control subjects. However, those with high exposures showed activation in more areas of the brain and different and wider patterns of activation than the low mixed exposure group. The brain activation patterns observed in association with increased exposures to MeHg and PCBs are meaningful in regard to the known neurotoxicity of these substances. This methodology therefore has potential utility in visualizing structural neural system determinants of exposure-induced neurobehavioral dysfunction. PMID:21545807

  11. Polychlorinated biphenyls in blue crabs from South Carolina

    SciTech Connect

    Marcus, J.M.; Mathews, T.D.

    1987-11-01

    Blue crabs are important members of the estuarine food web due to their numbers and their multiple roles as scavengers, predators and prey. Because of their omnivorous feeding characteristics, wide distribution an close association with bottom sediments, the potential exists for blue crabs to bioaccumulate pollutants residing in those sediments as has been shown for fiddler crabs. It follows that human health risk upon consumption of such crabs and biomagnification through the food web become primary concerns. During the spring of 1985, commercial crab fishermen in Beaufort County, South Carolina contacted the South Carolina Wildlife and Marine Resources Department (SCWMRD) concerning their perceptions of significantly declining catch rates in the Campbell Creek-Whale Branch area. Using knowledge of previously documented elevated polychlorinated biphenyls (PCB) levels in the sediments of the upper portion of Campbell Creek, the SCWMRD initiated analysis of crab tissue from the area to ascertain the body burdens of PCBs. Initial screening results indicated potentially significant levels of PCBs in blue crabs at which time, SCWMRD contacted the SC Department of Health and Environmental Control (SCDHEC) for more intensive study and definition of the situation. The work reported here was conducted between June and October 1985.

  12. Aqueous solubility of polychlorinated biphenyls related to molecular structure

    SciTech Connect

    Opperhulzen, A.; Gobas, F.A.P.C.; Van der Steen, J.M.D.; Hutzinger, O.

    1988-06-01

    Aqueous solubilities of polychlorinated biphenyls show a linear relationship between logarithms of aqueous activity coefficients and total surface areas (TSA) or total molecular volumes (TMV). The aqueous activity coefficients were calculated from experimental solubility data and values taken from the literature. The correlations improved substantially if a differential heat capacity between supercooled liquid and solid chemical (..delta..C/sub p/) equal to the entropy of fusion (..delta..S/sub f/), instead of ..delta..C/sub p/ = O, was assumed. In addition, it was found that dissolution of 2,2',4,4'-tetra- and 2,2',4,4'5,5'-hexachlorobiphenyl was accompanied by positive enthalpy and entropy changes, the entropy being dominant at room temperature. For the former compound, it was shown that the entropy of fusion is approximately to J K/sup -1/ mol/sup -1/, which is in agreement with the Walden rule. For 2,2',4,4',5,5'-hexachlorobiphenyl, it was shown that a Hildebrand plot provides a constant slope. This supported the assumption that differential heat capacity (..delta..C/sub p/) equals the entropy of fusion.

  13. Thyroid function in Yusho patients exposed to polychlorinated biphenyls (PCB)

    SciTech Connect

    Murai, K.; Okamura, K.; Tsuji, H.; Kajiwara, E.; Watanabe, H.; Akagi, K.; Fujishima, M.

    1987-12-01

    Thyroid function was investigated in 123 Yusho patients who were exposed to toxic levels of polychlorinated biphenyls (PCBs) 16 years ago. In Yusho patients, compared with the patients without evidence of Yusho or normal controls, the serum triiodothyronine (T/sub 3/) and thyroxine (T/sub 4/) levels were significantly higher, while thyroid stimulating hormone (TSH) levels measured by sensitive assay were normal. There was no difference in serum levels of albumin, alkaline phosphatase, total cholesterol, and thyroxine binding globulin (TBG) between the two groups and the prevalence of positive antithyroid autoantibodies was almost the same, suggesting that hyperthyroxinemia in Yusho patients was not due to increased TBG binding or abnormal autoimmune mechanism. Serum free T/sub 4/ levels, however, were not elevated, although T/sub 4//TBG ratio was significantly higher. The thyroid hormone levels were higher than normal value in 4 of 123 Yusho patients but only 1 case had clinical symptoms such as excessive perspiration. Despite higher serum PCBs in Yusho patients, there was no correlation between PCB levels and levels of T/sub 3/, T/sub 4/, or TSH. The present results suggest hyperthyroxinemia without obvious clinical symptoms in Yusho patients long after exposure to PCBs.

  14. The internal barriers of rotation for the 209 polychlorinated biphenyls.

    PubMed

    Andersson, P L; Haglund, P; Tysklind, M

    1997-01-01

    The internal barrier of rotation (Erot) was calculated for all 209 polychlorinated biphenyls (PCBs) by using a semi-empirical method, viz. the Austin Model 1 (AMI) Hamiltonian. The difference in total energy between a forced planar state and an optimised twisted structure was defined as Erot. The Erot values were in the range of 8.33 to 483 kJ/mol, and were significantly influenced by the number of chlorine atoms in ortho position. An additional structural characteristic of the PCBs influencing Erot of ortho substituted congeners was substitution by chlorine atoms in vicinal meta positions, which is assumed to prevent outward bending of ortho substituents. This so-called buttressing effect contributed with 4 to 31 kJ/mol per added chlorine atom. In conclusion, the internal barrier of rotation, calculated for all 209 PCBs, provides an important structure dependent physico-chemical parameter for multivariate modelling of future quantitative structure-activity and structure-property relationships (QSARs/QSPRs). PMID:19005788

  15. Polychlorinated Biphenyls Water Pollution along the River Nile, Egypt.

    PubMed

    Megahed, Ayman Mohamed; Dahshan, Hesham; Abd-El-Kader, Mahdy A; Abd-Elall, Amr Mohamed Mohamed; Elbana, Mariam Hassan; Nabawy, Ehab; Mahmoud, Hend A

    2015-01-01

    Ten polychlorinated biphenyl (PCB) congeners were determined in water samples collected along the River Nile using gas chromatography-electron capture detector (GC-ECD). PCB concentrations ranged from 14 to 20 μg/L, which were higher than those reported in previous studies, indicating serious PCB pollution in the River Nile. PCB congener profiles varied depending on the sampling sties. PCB-138 was the predominant congener accounting for more than 18% of total PCBs. The composition of PCB congeners in the water revealed that highly chlorinated PCB technical mixtures such as Aroclor 1254 was the main PCB production historically used in Egypt. An increasing trend in PCB levels from the upper stream to the Nile estuaries was observed. The calculated flux of PCBs indicated that 6.8 tons of PCBs is dumped into the Mediterranean Sea each year from the River Nile. The hazard quotients and carcinogenic risk caused by PCB pollution in the River Nile were above the acceptable level indicating that PCBs in the River Nile water pose adverse health effects for all age groups. Our findings revealed that PCBs possess a serious risk to the Egyptian population that depends mainly on the River Nile as a source of water. Thus, stricter legislation and regulatory controls should be applied to reduce the risk of PCBs in Egypt. PMID:26798844

  16. A reassessment of the nomenclature of polychlorinated biphenyl (PCB) metabolites.

    PubMed Central

    Maervoet, Johan; Covaci, Adrian; Schepens, Paul; Sandau, Courtney D; Letcher, Robert J

    2004-01-01

    Polychlorinated biphenyls (PCBs) are a widespread class of persistent organic chemicals that accumulate in the environment and humans and are associated with a broad spectrum of health effects. PCB biotransformation has been shown to lead to two classes of PCB metabolites that are present as contaminant residues in the tissues of selected biota: hydroxylated (HO) and methyl sulfone (MeSO2) PCBs. Although these two types of metabolites are related structures, different rules for abbreviation of both classes have emerged. It is important that a standardized nomenclature for the notation of PCB metabolites be universally agreed upon. We suggest that the full chemical name of the PCB metabolite and a shorthand notation should be adopted using the International Union of Pure and Applied Chemistry's chemical name/original Ballschmiter and Zell number of the parent congener, followed by the assignment of the phenyl ring position number of the MeSO2- or HO-substituent. This nomenclature provides a clear, unequivocal set of rules in naming and abbreviating the PCB metabolite structure. Furthermore, this unified PCB metabolite nomenclature approach can be extended to the naming and abbreviation of potential metabolites of structurally analogous contaminants such as HO-polybrominated biphenyls and HO-polybrominated diphenyl ethers. PMID:14998742

  17. Destruction of polychlorinated aromatic compounds by spinel-type complex oxides.

    PubMed

    Fan, Yun; Lu, Xianbo; Ni, Yuwen; Zhang, Haijun; Zhao, Liang; Chen, Jiping; Sun, Chenglin

    2010-04-15

    Destruction of polychlorinated aromatic compounds was carried out over spinel-type catalysts XY2O4 (where X = Mg, Ca, Cu, Ni, Zn, and Y = Al, Fe). The catalysts were characterized by XRD, nitrogen adsorption-desorption isotherms and FTIR. The performance of these catalysts toward the decomposition of hexachlorobenzene (HCB) and octachlorodibenzo-p-dioxin (OCDD) was evaluated in a closed system. The spinel-type catalyst with mesoporous structure demonstrated high catalytic activity for the hydrodechlorination of polychlorinated aromatic compounds. Among them, the copper-aluminum spinel (CuAl2O4), specifically calcined at 600 degrees C, exhibited the best activity. More than 85% dechlorination efficiency of HCB and 99% decomposition of polychlorinated dibenzodioxin (PCDD) were achieved at 250 degrees C for 30 min over the above catalyst which was more effective than the corresponding metallic copper and copper oxide catalysts during the thermal degradation of polychlorinated aromatic compounds. The correlation of catalytic performance to structural characteristics is discussed based on the detailed characterization. The simple preparation procedure and reasonable cost of the spinel-type catalysts present a good potential for the thermal treatment of polychlorinated aromatic pollutants at lower temperatures. PMID:20334415

  18. UPTAKE OF PLANAR POLYCHLORINATED BIPHENYLS AND 2,3,7,8-SUBSTITUTED POLYCHLORINATED DIBENZOFURANS AND DIBENZO-P-DIOXINS BY BIRDS NESTING IN THE LOWER FOX RIVER AND GREEN BAY, WI, USA

    EPA Science Inventory

    The uptake of persistent polychlorinated hydrocarbons (PCHs) by four avian species was investigated at upper trophic levels of two aquatic food chains of the lower Fox River and Green Bay, Wisconsin. ccumulation of total and specific planar polychlorinated biphenyls (PCBs), polyc...

  19. Seasonal variability of polychlorinated biphenyls (PCBs) and polychlorinated diphenyl ethers (PBDEs) congener profiles in butter in Poland: dietary risk evaluation.

    PubMed

    Roszko, Marek; Szymczyk, Krystyna; Rzepkowska, Małgorzata; Jędrzejczak, Renata

    2014-01-01

    Various statistical methods have been employed to analyse in details seasonal diversification of polychlorinated biphenyl (PCB)/polybrominated diphenyl ether (PBDE) congener profiles found in butter fat. The variability of the PCB/PBDE congener profiles indicates the presence of various sources of the milk fat contamination. The obtained results suggest that the environmental chemical background has the highest share in the contamination sources pattern. Ion trap mass spectrometry coupled to high-resolution gas chromatography with semi-permeable membrane dialysis sample cleanup was used for determination of PCBs and PBDEs in milk fat. Determined butter fat PCB profiles were similar to the profiles characteristic for Aroclor 1254 technical mixture. Our data indicate that dietary intake of PCB/PBDE with milk and milk products may be estimated to be about 717.5 pg kg b.w.(-1) day(-1) for six-indicator PCBs, 0.329 (equivalent toxicity, TEQ) pg kg b.w.(-1) day(-1) for 12 DL PCBs and 50 pg kg b.w.(-1) day(-1) for PBDEs (sum of 14 congeners). PMID:24380619

  20. EFFECT OF SULFUR DIOXIDE ON THE FORMATION MECHANISM OF POLYCHLORINATED DIBENZODIOXIN AND DIBENZOFURAN IN MUNICIPAL WASTE COMBUSTORS

    EPA Science Inventory

    The paper gives results of an investigation of the effect of S02 on the formation mechanism of polychlorinated dibenzodioxin (PCDD) and polychlorinated dibenzofuran (PCDF) in the post-combustion, downstream region (500 to 300 C) of a municipal waste combustor (MWC). Laboratory ex...

  1. EFFECTS OF COMBUSTION PARAMETERS ON POLYCHLORINATED DIBENZODIOXIN AND DIBENZOFURAN HOMOLOGUE PROFILES FROM MUNICIPAL WASTE AND COAL CO-COMBUSTION

    EPA Science Inventory

    Variation in polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran (PCDD and PCDF) homologue profiles from a pilot scale (0.6 MWt, 2x106 Btu/hr), co-fired-fuel [densified refuse derived fuel (dRDF) and high-sulfur Illinois coal] combustion system was used to provide i...

  2. Perinatal exposure to polychlorinated biphenyls alters social behaviors in rats

    PubMed Central

    Jolous-Jamshidi, Banafsheh; Cromwell, Howard C.; McFarland, Ashley M.; Meserve, Lee A.

    2014-01-01

    Perinatal exposure to polychlorinated biphenyls (PCBs) leads to significant alterations of neural and hormonal systems. These alterations have been shown to impair motor and sensory development. Less is known about the influence of PCB exposure on developing emotional and motivational systems involved in social interactions and social learning. The present study examined the impact of perinatal PCB exposure (mixture of congeners 47 and 77) on social recognition in juvenile animals, conspecific-directed investigation in adults and on neural and hormonal systems involved in social functions. We used a standard habituation–dishabituation paradigm to evaluate juvenile recognition and a social port paradigm to monitor adult social investigation. Areal measures of the periventricular nucleus (PVN) of the hypothalamus were obtained to provide correlations with related hormone and brain systems. PCB exposed rats were significantly impaired in social recognition as indicated by persistent conspecific-directed exploration by juvenile animals regardless of social experience. As adults, PCB exposure led to a dampening of the isolation-induced enhancement of social investigation. There was not a concomitant alteration of social investigation in pair-housed PCB exposed animals at this stage of development. Interestingly, PVN area was significantly decreased in juvenile animals exposed to PCB during the perinatal period. Shifts in hypothalamic regulation of hormones involved in social behavior and stress could be involved in the behavioral changes observed. Overall, the results suggest that PCB exposure impairs context or experience-dependent modulation of social approach and investigation. These types of social-context deficits are similar to behavioral deficits observed in social disorders such as autism and other pervasive developmental disorders. PMID:20813172

  3. Phytoremediation of Polychlorinated Biphenyls: New Trends and Promises

    PubMed Central

    Van Aken, Benoit; Correa, Paola A.; Schnoor, Jerald L.

    2011-01-01

    Transgenic plants and associated bacteria constitute a new generation of genetically modified organisms for efficient and environmental-friendly treatment of soil and water contaminated with polychlorinated biphenyls (PCBs). This review focuses on recent advances in phytoremediation for the treatment of PCBs, including the development of transgenic plants and associated bacteria. Phytoremediation, or the use of higher plants for rehabilitation of soil and groundwater, is a promising strategy for cost-effective treatment of sites contaminated by toxic compounds, including toxic PCBs. Plants can help mitigate environmental pollution by PCBs through a range of mechanisms: besides uptake from soil (phytoextraction), plants are capable of enzymatic transformation of PCBs (phytotransformation); by releasing a variety of secondary metabolites, plants also enhance the microbial activity in the root zone, improving biodegradation of PCBs (rhizoremediation). However, because of their hydrophobicity and chemical stability, PCBs are only slowly taken up and degraded by plants and associated bacteria, resulting in incomplete treatment and potential release of toxic metabolites into the environment. Moreover, naturally occurring plant-associated bacteria may not possess the enzymatic machinery necessary for PCB degradation. In order to overcome these limitations, bacterial genes involved in the metabolism of PCBs, such as biphenyl dioxygenases, have been introduced into higher plants, following a strategy similar to the development of transgenic crops. Similarly, bacteria have then been genetically modified that exhibit improved biodegradation capabilities and are able to maintain stable relationships with plants. Transgenic plants and associated bacteria bring hope for a broader and more efficient application of phytoremediation for the treatment of PCBs. PMID:20384372

  4. Human receptor activation by aroclor 1260, a polychlorinated biphenyl mixture.

    PubMed

    Wahlang, Banrida; Falkner, K Cameron; Clair, Heather B; Al-Eryani, Laila; Prough, Russell A; States, J Christopher; Coslo, Denise M; Omiecinski, Curtis J; Cave, Matthew C

    2014-08-01

    Polychlorinated biphenyls (PCBs) are persistent environmental toxicants, present in 100% of U.S. adults and dose-dependently associated with obesity and non-alcoholic fatty liver disease (NAFLD). PCBs are predicted to interact with receptors previously implicated in xenobiotic/energy metabolism and NAFLD. These receptors include the aryl hydrocarbon receptor (AhR), pregnane xenobiotic receptor (PXR), constitutive androstane receptor (CAR), peroxisome proliferator-activated receptors (PPARs), liver-X-receptor (LXRα), and farnesoid-X-receptor (FXR). This study evaluates Aroclor 1260, a PCB mixture with congener composition mimicking that of human adipose tissue, and selected congeners, as potential ligands for these receptors utilizing human hepatoma-derived (HepG2) and primate-derived (COS-1) cell lines, and primary human hepatocytes. Aroclor 1260 (20 μg/ml) activated AhR, and PCB 126, a minor component, was a potent inducer. Aroclor 1260 activated PXR in a simple concentration-dependent manner at concentrations ≥10 μg/ml. Among the congeners tested, PCBs 138, 149, 151, 174, 183, 187, and 196 activated PXR. Aroclor 1260 activated CAR2 and CAR3 variants at lower concentrations and antagonize CAR2 activation by the CAR agonist, CITCO, at higher concentrations (≥20 μg/ml). Additionally, Aroclor 1260 induced CYP2B6 in primary hepatocytes. At subtoxic doses, Aroclor 1260 did not activate LXR or FXR and had no effect on LXR- or FXR-dependent induction by the agonists T0901317 or GW4064, respectively. Aroclor 1260 (20 μg/ml) suppressed PPARα activation by the agonist nafenopin, although none of the congeners tested demonstrated significant inhibition. The results suggest that Aroclor 1260 is a human AhR, PXR and CAR3 agonist, a mixed agonist/antagonist for CAR2, and an antagonist for human PPARα. PMID:24812009

  5. Association between polychlorinated biphenyls and Parkinson’s disease neuropathology

    PubMed Central

    Hatcher-Martin, Jaime M.; Gearing, Marla; Steenland, Kyle; Levey, Allan I.; Miller, Gary W.; Pennell, Kurt D.

    2012-01-01

    Polychlorinated biphenyls (PCBs) are synthetic chemicals primarily used as coolants and insulators in electrical equipment. Although banned for several decades, PCBs continue to exist in the environment because of their long half-life, continued presence in items produced before the ban, and poor disposal practices. Epidemiological and experimental studies have identified exposure to PCBs as a potential risk factor for Parkinson’s disease, perhaps more so in females. The objective of this work was to examine the association between PCB levels in post-mortem human brain tissue and the diagnosis of Parkinson’s disease, as well as the degree of nigral depigmentation. We also sought to determine if this association was more significant when patients were stratified by sex. Post-mortem brain samples from control patients and those diagnosed with Parkinson’s disease were obtained from the Emory University Brain Bank and from the Nun Study. Concentrations of eight prevalent PCB congeners were extracted from post-mortem brain tissue and analyzed using gas chromatography-mass spectrometry. PCB congeners 153 and 180 were significantly elevated in the brains of Parkinson’s disease patients. When stratified by sex, the female Parkinson’s disease group demonstrated significantly elevated concentrations of total PCBs and specifically congeners 138, 153, and 180 compared to controls, whereas PCB concentrations in males were not significantly different between control and Parkinson’s disease groups. In a separate population of women (Nun Study) who had no clinical signs or symptoms of PD, elevated concentrations total PCB and congeners 138, 153 and 180 were also observed in post-mortem brain tissue exhibiting moderate nigral depigmentation compared to subjects with mild or no depigmentation. These quantitative data demonstrate an association between brain PCB levels and Parkinson’s disease-related pathology. Furthermore, these data support epidemiological and

  6. Formation and stability of polychlorinated biphenyl Pickering emulsions

    NASA Astrophysics Data System (ADS)

    Roy-Perreault, Andréanne; Kueper, Bernard H.; Rawson, Jim

    2005-03-01

    An emulsion stabilized by colloidal suspensions of finely divided solids is known as a Pickering emulsion. The potential for polychlorinated biphenyls (PCBs) to form Pickering emulsions ex situ when in contact with powdered solids, such as clays and metal oxides, is investigated here. Bentonite, iron oxide and magnesium oxide dispersions proved to be robust Pickering emulsion stabilizers, whereas manganese oxide dispersions were not. Batch experiments revealed that emulsions can be formed using a moderately low energy input and can be stabilized with solid concentrations as low as 0.5 wt.%. For the base conditions (volumetric oil fraction ( ϕoil)=30 vol.%; solid concentration ( χ)=2 wt.%), the formed emulsions were indefinitely stable and the initial average droplet diameters varied from 80 to 258 μm, depending on the solid used in the colloidal dispersion. The average droplet size varied at early time, but for most conditions stabilized to a steady-state value 1 week after preparation. The effect of Ostwald ripening was limited. At greater than 0.5 wt.% concentration, the efficiency of the solid dispersion as a stabilizer was dependant on the volumetric oil fraction but not on the solid concentration. Generally, systems with volumetric oil fractions outside of the 20-70 vol.% range were unstable. The emulsions' droplet stability, average droplet size and size distribution were observed to vary as a function of the amount of energy provided to the system, the volumetric oil fraction, and the concentration of the solid in the aqueous dispersion. It is hypothesized that drilling through fractured rock in the immediate vicinity of dense, non-aqueous phase liquid (DNAPL) PCBs may provide both the energy and solid material necessary to form Pickering emulsions.

  7. Human Receptor Activation by Aroclor 1260, a Polychlorinated Biphenyl Mixture

    PubMed Central

    Wahlang, Banrida; Falkner, K. Cameron; Clair, Heather B.; Al-Eryani, Laila; Prough, Russell A.; States, J. Christopher; Coslo, Denise M.; Omiecinski, Curtis J.; Cave, Matthew C.

    2014-01-01

    Polychlorinated biphenyls (PCBs) are persistent environmental toxicants, present in 100% of U.S. adults and dose-dependently associated with obesity and non-alcoholic fatty liver disease (NAFLD). PCBs are predicted to interact with receptors previously implicated in xenobiotic/energy metabolism and NAFLD. These receptors include the aryl hydrocarbon receptor (AhR), pregnane xenobiotic receptor (PXR), constitutive androstane receptor (CAR), peroxisome proliferator-activated receptors (PPARs), liver-X-receptor (LXRα), and farnesoid-X-receptor (FXR). This study evaluates Aroclor 1260, a PCB mixture with congener composition mimicking that of human adipose tissue, and selected congeners, as potential ligands for these receptors utilizing human hepatoma-derived (HepG2) and primate-derived (COS-1) cell lines, and primary human hepatocytes. Aroclor 1260 (20 μg/ml) activated AhR, and PCB 126, a minor component, was a potent inducer. Aroclor 1260 activated PXR in a simple concentration-dependent manner at concentrations ≥10 μg/ml. Among the congeners tested, PCBs 138, 149, 151, 174, 183, 187, and 196 activated PXR. Aroclor 1260 activated CAR2 and CAR3 variants at lower concentrations and antagonize CAR2 activation by the CAR agonist, CITCO, at higher concentrations (≥20 μg/ml). Additionally, Aroclor 1260 induced CYP2B6 in primary hepatocytes. At subtoxic doses, Aroclor 1260 did not activate LXR or FXR and had no effect on LXR- or FXR-dependent induction by the agonists T0901317 or GW4064, respectively. Aroclor 1260 (20 μg/ml) suppressed PPARα activation by the agonist nafenopin, although none of the congeners tested demonstrated significant inhibition. The results suggest that Aroclor 1260 is a human AhR, PXR and CAR3 agonist, a mixed agonist/antagonist for CAR2, and an antagonist for human PPARα. PMID:24812009

  8. Perinatal exposure to polychlorinated biphenyls alters social behaviors in rats.

    PubMed

    Jolous-Jamshidi, Banafsheh; Cromwell, Howard C; McFarland, Ashley M; Meserve, Lee A

    2010-11-30

    Perinatal exposure to polychlorinated biphenyls (PCBs) leads to significant alterations of neural and hormonal systems. These alterations have been shown to impair motor and sensory development. Less is known about the influence of PCB exposure on developing emotional and motivational systems involved in social interactions and social learning. The present study examined the impact of perinatal PCB exposure (mixture of congeners 47 and 77) on social recognition in juvenile animals, conspecific-directed investigation in adults and on neural and hormonal systems involved in social functions. We used a standard habituation-dishabituation paradigm to evaluate juvenile recognition and a social port paradigm to monitor adult social investigation. Areal measures of the periventricular nucleus (PVN) of the hypothalamus were obtained to provide correlations with related hormone and brain systems. PCB exposed rats were significantly impaired in social recognition as indicated by persistent conspecific-directed exploration by juvenile animals regardless of social experience. As adults, PCB exposure led to a dampening of the isolation-induced enhancement of social investigation. There was not a concomitant alteration of social investigation in pair-housed PCB exposed animals at this stage of development. Interestingly, PVN area was significantly decreased in juvenile animals exposed to PCB during the perinatal period. Shifts in hypothalamic regulation of hormones involved in social behavior and stress could be involved in the behavioral changes observed. Overall, the results suggest that PCB exposure impairs context or experience-dependent modulation of social approach and investigation. These types of social-context deficits are similar to behavioral deficits observed in social disorders such as autism and other pervasive developmental disorders. PMID:20813172

  9. Dietary uptake of polychlorinated biphenyls (PCBs) by rainbow trout

    USGS Publications Warehouse

    Carline, Robert F.; Barry, Patrick M.; Ketola, H. George

    2004-01-01

    The presence of detectable levels of polychlorinated biphenyls (PCBs) in commercially produced fish feed has raised a concern about the degree of biomagnification of these contaminants in hatchery-reared trout. Our objectives were to (1) define the relationship between concentrations of PCBs in fish feed and in fish tissue and (2) estimate the relative contributions of feed and hatchery supply water to PCB concentrations in fish. We conducted a 6-month feeding trial with fingerling rainbow trout Oncorhynchus mykiss fed commercial diets with four concentrations of PCBs: a low-PCB diet (69 ng/g); a typical commercial diet (126 ng/g); and the typical diet spiked with PCBs at two levels (220 and 280 ng/g). The concentrations of PCBs in fillets after 1 month were commensurate with those in the feeds and remained relatively stable for the next 5 months; mean PCB concentrations in fillets ranged from 54 to 94 ng/g. Low levels of PCBs were detected in the hatchery supply water. We used the concentrations of PCBs in the feeds, absorption rates of PCBs, and two different rates of PCB depuration to estimate the potential uptake of PCBs from supply water. When we used a low depuration rate (half-life = 219 d), the computed body burdens of PCBs could be entirely attributed to the feeds. When a high depuration rate (half-life = 66 d) was used, some uptake of PCBs from the supply water was likely, but most of the total body burden originated from the feeds. We concluded that rainbow trout fed a diet with 126 ng/g PCBs would have a PCB concentration of about 60 ng/g in their fillets, which is high enough to warrant issuance of a consumption advisory (no more than one meal of fish per week) under a protocol adopted by some Great Lakes states.

  10. Striped bass stocks and concentrations of polychlorinated biphenyls

    USGS Publications Warehouse

    Fabrizio, Mary C.; Sloan, Ronald J.; O'Brien, John F.

    1991-01-01

    Harvest restrictions on striped bass Morone saxatilis fisheries in Atlantic coastal states were relaxed in 1990, but consistent, coastwide regulations of the harvest have been difficult to implement because of the mixed-stock nature of the fisheries and the recognized contamination of Hudson River fish by polychlorinated biphenyls (PCBs). We examined PCB concentrations and stock of origin of coastal striped bass to better understand the effects of these two factors on the composition of the harvest. The probability of observing differences in PCB concentration among fish from the Hudson River stock and the 'southern' group (Chesapeake Bay and Roanoke River stocks combined) was investigated with the logit model (a linear model for analysis of categorical data). Although total PCB concentrations were highly variable among fish from the two groups, striped bass classified as Hudson River stock had a significantly greater probability of having PCB concentrations equal to or greater than 2.00 mg/kg than did fish belonging to the southern group for all age- and size-classes examined. There was a significantly greater probability of observing total PCB concentrations equal to or exceeding 2.00 mg/kg in fish that were 5, 6, and 7 or more years old, and this probability increased linearly with age. We observed similar results when we examined the effect of size on total PCB concentration. The minimum-size limit estimated to permit escapement of fish to sustain stock production is 610 mm total length. Unless total PCB concentrations decrease in striped bass, it is likely that many harvestable fish will have concentrations that exceed the tolerance limit set by the U.S. Food and Drug Administration.

  11. Pan-arctic river fluxes of polychlorinated biphenyls.

    PubMed

    Carrizo, Daniel; Gustafsson, Örjan

    2011-10-01

    Observations of polychlorinated biphenyls (PCB) concentrations in fluvial surface sediments near the mouths of the six Great Arctic Rivers (GARs; Ob, Yenisey, Lena, Indigirka, Kolyma, and Mackenzie) were combined with annual dissolved organic carbon (DOC) and particulate organic carbon (POC) loadings and hydraulic discharge to estimate the pan-Arctic river flux of PCBs. The highest total-phase fluxes of ∑(13)PCB were found for the Ob River, with 184 kg/yr and the smallest for the Indigirka River with 3.9 kg/yr. Consistent with a continent-scale trend among the Eurasian GARs of increasing POC concentrations eastward, which is extending to the North American Mackenzie River, a general shift in the estimated PCB partitioning from dissolved to particle-associated flux was found toward the east. Pentachlorinated and hexachlorinated PCBs constituted the majority (>70%) of the total PCB fluxes in the Eurasian Rivers. In contrast, trichlorinated and tetrachlorinated congeners were the most abundant in the Mackenzie (≈ 75%). The total ∑(13)PCB fluxes from the pan-Arctic rivers are here estimated to be ∼0.4 tonne/yr. This is geochemically consistent with the inventory of total PCBs in the Polar Mixed Layer of the entire Arctic Ocean (0.39 tonne) and about a factor 2 less than two new estimates of the PCB settling export to Arctic subsurface waters. Hence, the yearly Great Arctic River PCB fluxes only represent 0.001% of the historical PCB emission into the global environment. To our knowledge, this is the first estimate of circum-Arctic river flux of any organic pollutant based on a comprehensive investigation of the pollutants in several rivers and it contributes toward a more complete understanding of large-scale contaminant cycling in the Arctic. PMID:21863827

  12. Damaging effects of polychlorinated biphenyls on chicken primordial germ cells.

    PubMed

    Fang, Changge; Zhang, Caiqiao; Xia, Guoliang; Yang, Wei

    2002-01-01

    This work describes the effects of a commercial polychlorinated biphenyl (PCB) mixture, Aroclor 1254, as well as 17beta-oestradiol (E2) and testosterone on numbers and histomorphological changes of primordial germ cells (PGCs) in gonadal regions of Day 5 Hyline chicken embryos. The oestrogen receptor antagonist, clomiphen, alone or with PCBs was used in an attempt to protect the developing gonad from oestrogen-like effects of chemical PCBs. The results were as follows: (i) PCBs delayed embryonic development independently of dose (1 microg/egg, P<0.05; 10 microg/egg, P<0.01; 100 microg/egg, P<0.001 v. the control) and caused a dose-independent increase in mortality compared with the control group (10 microg/egg, P<0.01; 100 microg/egg, P<0.05); maximal mortality was observed in the 1 microg/egg group (P<0.001); (ii) PCBs decreased PGC numbers dose dependently (P<0.001) and caused a swollen nucleus with hyperchromatism (pyknosis) or cytoplasm vacuolation as signs of gonadal PGC degeneration in all PCB groups, or even complete disappearance in the 100 microg/egg group; (iii) after PCB treatment, the index of gonadal lesion increased significantly with the decrease of gonadal PGC number (1, 10 and 100 microg/egg, P<0.001); (iv) there were no observed effects of E2, testosterone and clomiphen on PGCs in the experiments; and (v) clomiphen failed to block the damaging effects of PCBs. These results suggest that the adverse effects of PCBs on chicken gonadal and germ cell development were initiated during the early stages of incubation through direct toxic effects, rather than through oestrogen-mimicking actions. As PGC numbers in the gonads decrease and the index of gonadal lesion increases, one may expect reproductive function to be compromised. PMID:12219939

  13. Immunotoxicity Monitoring in a Population Exposed to Polychlorinated Biphenyls

    PubMed Central

    Haase, Hajo; Fahlenkamp, Astrid; Schettgen, Thomas; Esser, Andre; Gube, Monika; Ziegler, Patrick; Kraus, Thomas; Rink, Lothar

    2016-01-01

    The relationship between polychlorinated biphenyl (PCB) burden and several indicators of immune function was investigated as part of the HELPcB (Health Effects in High-Level Exposure to PCB) program, offering bio-monitoring to workers, relatives, and neighbors exposed to PCBs by a German transformers and capacitors recycling company. The present retrospective observational study evaluates the correlation of plasma levels of total PCBs, five indicator congeners (28, 101, 138, 153, 180), and seven dioxin-like congeners (105, 114, 118, 156, 157, 167, 189) with several parameters of immune function. The cross-sectional study was performed immediately after the end of exposure (258 subjects), and one (218 subjects), and two (177 subjects) years later. At the first time point, measurements showed significant positive correlation between congeners with low to medium chlorination and the relative proportion of CD19 positive B-cells among lymphocytes, as well as a negative correlation of PCB114 with serum IgM, and of PCB 28 with suppressor T-cell and NK-cell numbers. Congeners with a high degree of chlorination, in particular PCB157 and 189, were positively associated with expression of the activation marker CD25 on T-cells in the cohort of the second time point. No associations between PCB levels and IFN-y production by T-cells and killing by NK-cells were found. In conclusion, there were several effects on the cellular composition of adaptive immunity, affecting both T- and B-cells. However, the values were not generally outside the reference ranges for healthy adult individuals and did not indicate overt functional immunodeficiency, even in subjects with the uppermost PCB burden. PMID:27005643

  14. Immunotoxicity Monitoring in a Population Exposed to Polychlorinated Biphenyls.

    PubMed

    Haase, Hajo; Fahlenkamp, Astrid; Schettgen, Thomas; Esser, Andre; Gube, Monika; Ziegler, Patrick; Kraus, Thomas; Rink, Lothar

    2016-03-01

    The relationship between polychlorinated biphenyl (PCB) burden and several indicators of immune function was investigated as part of the HELPcB (Health Effects in High-Level Exposure to PCB) program, offering bio-monitoring to workers, relatives, and neighbors exposed to PCBs by a German transformers and capacitors recycling company. The present retrospective observational study evaluates the correlation of plasma levels of total PCBs, five indicator congeners (28, 101, 138, 153, 180), and seven dioxin-like congeners (105, 114, 118, 156, 157, 167, 189) with several parameters of immune function. The cross-sectional study was performed immediately after the end of exposure (258 subjects), and one (218 subjects), and two (177 subjects) years later. At the first time point, measurements showed significant positive correlation between congeners with low to medium chlorination and the relative proportion of CD19 positive B-cells among lymphocytes, as well as a negative correlation of PCB114 with serum IgM, and of PCB 28 with suppressor T-cell and NK-cell numbers. Congeners with a high degree of chlorination, in particular PCB157 and 189, were positively associated with expression of the activation marker CD25 on T-cells in the cohort of the second time point. No associations between PCB levels and IFN-y production by T-cells and killing by NK-cells were found. In conclusion, there were several effects on the cellular composition of adaptive immunity, affecting both T- and B-cells. However, the values were not generally outside the reference ranges for healthy adult individuals and did not indicate overt functional immunodeficiency, even in subjects with the uppermost PCB burden. PMID:27005643

  15. Ecotoxicology of polychlorinated biphenyls in fish--a critical review.

    PubMed

    Henry, T B

    2015-01-01

    Polychlorinated biphenyls (PCBs) are widespread persistent anthropogenic contaminants that can accumulate in tissues of fish. The toxicity of PCBs and their transformation products has been investigated for nearly 50 years, but there is a lack of consensus regarding the effects of these environmental contaminants on wild fish populations. The objective of this review is to critically examine these investigations and evaluate publicly available databases for evidence of effects of PCBs in wild fish. Biological activity of PCBs is limited to a small proportion of PCB congeners [e.g., dioxin-like PCBs (DL-PCBs)] and occurs at concentrations that are typically orders of magnitude higher than PCB levels detected in wild fish. Induction of biomarkers consistent with PCB exposure (e.g., induction of cytochrome P450 monooxygenase system) has been evaluated frequently and shown to be induced in fish from some environments, but there does not appear to be consistent reports of damage (i.e., biomarkers of effect) to biomolecules (i.e., oxidative injury) in these fish. Numerous investigations of endocrine system dysfunction or effects on other organ systems have been conducted in wild fish, but collectively there is no consistent evidence of PCB effects on these systems in wild fish. Early life stage toxicity of DL-PCBs does not appear to occur at concentrations reported in wild fish embryos, and results do not support an association between PCBs and decreased survival of early life stages of wild fish. Overall, there appears to be little evidence that PCBs have had any widespread effect on the health or survival of wild fish. PMID:25945423

  16. Polychlorinated biphenyls in Spanish adults: Determinants of serum concentrations

    SciTech Connect

    Agudo, Antonio; Goni, Fernando; Etxeandia, Arsenio; Vives, Asuncion; Millan, Esmeralda; Lopez, Raul; Amiano, Pilar; Ardanaz, Eva; Barricarte, Aurelio; Dolores Chirlaque, M.; Dorronsoro, Miren; Jakszyn, Paula; Larranaga, Nerea; Martinez, Carmen; Navarro, Carmen; Rodriguez, Laudina; and others

    2009-07-15

    Background: Polychlorinated biphenyls (PCBs) are persistent compounds that may pose an environmental hazard to humans, food being the main source of exposure for the general population. Objective: To measure the serum concentrations of the main PCBs in subjects from the general population in Spain, and to assess potential determinants of such concentrations. Methods: Serum was obtained from blood samples of 953 subjects aged 35-64 years, residents in five Spanish regions (three from the North and two from the South), randomly selected from the EPIC-Spain cohort. Blood collection took place during 1992-1996 and four PCB congeners (118, 138, 153 and 180) were determined by means of gas chromatography with electron-capture detection (GC-ECD). Results: The concentration of total PCBs was 459 ng/g lipids (or 3.1 {mu}g/l); the corresponding figures for PCB 153 were 186 ng/g lipids and 1.25 {mu}g/l. Men had higher values than women, PCB levels increased with age, and serum concentration of PCBs was higher in northern regions. Body mass index (BMI) was inversely related to PCB concentrations, and fish intake was the dietary factor showing the greatest association with serum PCBs. The pattern described was similar for each congener separately. Conclusions: We found concentrations similar to those reported in European countries where blood collection was carried during the same period. Regional differences within Spain are not fully explained by anthropometric or dietary factors. The inverse association with BMI suggests that in the mid-1990s there was still ongoing or recent exposure to PCBs in Spain.

  17. Transfer of polychlorinated biphenyls to infants from their mothers

    SciTech Connect

    Kodama, H.; Ota, H.

    1980-03-01

    Transfer of polychlorinated biphenyls (PCBs) which are environmental pollutants, to infants from their mothers was investigated from 1974 to 1977. The following samples were collected and analyzed for PCBs using a gas chromatographic determination: (a) maternal blood at 8 and 4 months prepartum, delivery, and 1, 3, 5, and 7 months postpartum; (b) cord blood at delivery; (c) human milk at 1, 3, 5, and 7 months postpartum; and (d) newborn infant blood at 3 months, 1, 2, and 3 yr after birth. The PCB levels in maternal blood gradually elevated with the progress of gestation and then decreased, reaching a general population level at 5 months postpartum. The PCB level in maternal blood at delivery was significantly higher than that in the cord blood. The mean values of PCB levels in human milk at 3 months postpartum-both the whole and fat basis-showed some differences in each sampling time period, however, those values were generally obtained within the normal range of ordinary Japanese lactating women. When the cord blood at delivery was considered as newborn infant blood at birth, the PCB levels in the blood of breast-fed infants rose markedly with ingestion of human milk, exceeding the level in the blood of their mothers at 3 months postpartum, and tended to increase until 1 yr of age, and then gradually decreased at 2 and 3 yr of age. However, the PCB levels in the blood of bottle-fed infants remained at a low concentration level during the same period. In this survey, the concentration of PCBs in the blood of two newborn infants who received their mothers' milk for a longer period of time than the other infants, continued to increase exponentially, finally reaching about a four-fold value of their mothers. These results suggest that the quantity of PCBs transferred to infants from their mothers via lactation was much greater than that transferred placentally.

  18. Guidance on the management of polychlorinated biphenyls (PCBs)

    SciTech Connect

    Not Available

    1993-11-01

    Polychlorinated biphenyls (PCBs) are a class of synthetic organic chemicals including 209 known isomers, each with from 1 to 10 chlorine atoms on a biphenyl ring. PCBs have a number of desirable properties for industrial applications including thermal stability, flame retardance, and low vapor pressure. Because of these properties, PCBs were widely used as dielectric fluid in electrical equipment such as utility transformers and capacitors. PCBs were also extensively used in hydraulic fluid and heat transfer fluid, in gaskets, as additives in cutting oils and lubricant, and in a variety of other uses. The Toxic Substances Control Act (TSCA) banned the manufacture of PCBs after 1978 in response to emerging information about the adverse health effects of PCBs and their persistence in the environment. In addition, TSCA directed the Administrator of the Environmental Protection Agency (EPA) to prescribe methods for disposal of PCBS, require marking of PCBs with warning labels, and control their use. The TSCA regulations allow continued use of PCBs provided that the use is totally enclosed and does not pose a risk to human health or the environment. However, at the end of their useful life, all PCB materials must be disposed of according to the TSCA regulations. This guidance document uses graphics and flow charts where possible to present the TSCA regulations according to management activities such as use, storage, disposal, and spill cleanup. The document is designed to be read on an as-needed basis; that is, each chapter can stand alone or may be read in combination with others to help the reader determine the regulations relevant to his or her individual situation and needs. Every attempt has been made to include the requirements of other statutes and regulations that apply to PCB materials and provide references for the reader to consult for additional information.

  19. Dioxins (polychlorinated dibenzo-p-dioxins and polychlorinated dibenzo-furans) in traditional clay products used during pregnancy.

    PubMed

    Reeuwijk, Noortje M; Talidda, Antonia; Malisch, Rainer; Kotz, Alexander; Tritscher, Angelika; Fiedler, Heidelore; Zeilmaker, Marco J; Kooijman, Martin; Wienk, Koen J H; Traag, Wim A; Hoogenboom, Ron L A P

    2013-02-01

    Geophagy, the practice of consuming clay or soil, is encountered among pregnant women in Africa, Eastern Asia and Latin America, but also in Western societies. However, certain types of clay are known to contain high concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). The aim of this study was to determine the PCDD/F contents of orally consumed clays purchased from Dutch and African markets. Congener patterns were compared with those of pooled human milk samples collected in eight African countries, to investigate a possible relationship with clay consumption. From the Dutch market thirteen clay products were examined, seven of African and six of Suriname origin. From seven African countries, twenty clay products were collected. All 33 clay products were screened with a cell-based bioassay and those showing a high response were analyzed by GC/HRMS. High PCDD/F concentrations were measured in three clay products from the Dutch market, ranging from 66 to 103 pg TEQ g(-1), whereas clay products from African countries were from 24 to 75 pg TEQ g(-1). Patterns and relatively high concentrations of PCDD/Fs in human milk samples from the Democratic Republic of the Congo and Côte d'Ivoire suggest a relationship with the consumption of contaminated clay. Frequent use of PCDD/F contaminated clay products during pregnancy may result in increased exposure of the mother and subsequently the developing fetus and new-born child. The use of these contaminated clays during pregnancy should be carefully considered or even discouraged. PMID:23159200

  20. Exposure to a Mixture of Polychlorinated Biphenyls and Polychlorinated Dibenzofurans Resulted in a Prolonged Time to Pregnancy in Women

    PubMed Central

    Yang, Chiu-Yueh; Wang, Ying-Jan; Chen, Pau-Chung; Tsai, Shaw-Jenq; Guo, Yueliang Leon

    2008-01-01

    Background Polychlorinated biphenyls (PCBs), dibenzofurans (PCDFs), and dibenzodioxins (PCDDs) may affect the female reproductive system in animals and humans. In 1978–1979, a mass poisoning occurred in central Taiwan due to PCB/PCDF-contaminated cooking oil; this incident was called Yucheng (“oil disease” in Chinese). Objective The purpose of our study was to determine whether PCB/PCDF exposure affected fertility in exposed women. Methods After the event, we followed the exposed individuals and a reference group who were sex-, age-, and community-matched. In 2003, we obtained fertility histories from Yucheng and reference women by telephone interview. We used Kaplan–Meier survival curves and multivariable Cox regression to compare time to pregnancy (TTP) between Yucheng and reference women, and we performed multiple logistic regression to determine whether PCB/PCDF exposure caused infertility. Results In total, 412 women responded, with a median TTP of 4 months in Yucheng women and 3 months in reference women (p = 0.019). After adjusting for confounders by Cox regression, we found a fecundability ratio of 0.90 [95% confidence interval (CI), 0.80–1.00] for Yucheng women. Among the 408 women who had noncontraceptive sexual activity for > 12 months, 19.7% of Yucheng women and 9.7% of reference women did not become pregnant (i.e., they were infertile). After we adjusted for confounders by logistic regression, the infertility odds ratio was 2.34 (95% CI, 1.23–4.59) for Yucheng women compared with the reference group. Conclusions We found prolonged TTP and reduced fertility among women previously exposed to PCBs/PCDFs. Because of the limited sample size and the relatively small decrease in the fertility rate, these effects require cautious interpretation and further investigation for confirmation. PMID:18470317

  1. Disposition of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in two Norwegian epibenthic marine food webs.

    PubMed

    Ruus, Anders; Berge, John Arthur; Bergstad, Odd Aksel; Knutsen, Jan Atle; Hylland, Ketil

    2006-03-01

    Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) are a group of halogenated hydrocarbons, comprising 210 different, theoretically possible congeners. They are relatively hydrophobic and persistent to biodegradation, thereby rendering them subject to bioaccumulation. This study was conducted in Frierfjord and Eidangerfjord in the Grenland fjord system, Norway, heavily polluted by PCDD/PCDF discharges from the 16,600,859 magnesium production at Herøya from 1951 to 2001. Pooled samples of surface-sediments and the following organisms were collected for the Frierfjord and Eidangerfjord study areas: common shrimp (Crangon crangon), polychaetes (mainly Nereis diversicolor), shore crab (Carcinus maenas), cod (Gadus morhua), flounder (Platichthys flesus), trout (Salmo trutta), herring (Clupea harengus), benthic amphipods and zooplankton. Concentrations of 2,3,7,8-PCDD/Fs were quantified in pooled samples for all species. The relative abundances of stable isotopes of nitrogen (delta(15)N) were evaluated in the organisms as a measure of chemically-derived trophic level. Contrary to earlier studies on other persistent organochlorines, it was found that the concentrations of PCDD/Fs declined with increasing trophic level. Principal Component Analysis (PCA) also showed differences between species in the pattern of PCDD/Fs. Higher chlorinated congeners constituted lower percentages of the PCDD/F-concentrations higher in the food chain as compared to lower trophic levels. In general, congener patterns did not differ between fjords. Infauna (polychaetes) and zooplankton had congener patterns most similar to the pollution source. The results indicate lower accumulation of higher chlorinated congeners in species at higher trophic levels (fish), presumably due to low membrane permeability (high molecular size) and possibly slow transport through intestinal aqueous phases because of low aqueous solubility. PMID:16169571

  2. Polychlorinated biphenyls (PCBs), polychlorinated diphenyl ethers (PBDEs) and organochlorine pesticides in selected cereals available on the Polish retail market.

    PubMed

    Roszko, Marek; Jędrzejczak, Renata; Szymczyk, Krystyna

    2014-01-01

    Polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and organochlorine pesticides (DDT, HCH, HCB, chlordane, endrin, dieldrin, aldrin, nitrophene, metoxychlor) are man-made chemicals manufactured for numerous applications. The aim of this study was to assess levels of PCBs, PBDEs, and organochlorine pesticides in selected types of cereals available on the Polish retail market. 191 samples of various cereals have been analyzed in total. Average EC6 concentrations ranged from 56.4 (snacks) to 442.2 pg g(-1) (bran) while the concentration of 12 dioxin-like PCBs was in 15 (groats)-37.6 pg g(-1) (snacks) range. Mean dioxin equivalency concentration calculated as lower bound results in 2005 TEF values amounted to 0.120 ± 0.445 pg TEQ g(-1), while 0.091 ± 0.338 pg TEQ g(-1) if 1998 TEF values were used. Average concentration of all 14 studied BDEs (∑14 BDE) was 112 ± 80 pg g(-1), while average concentration of 13 BDEs excluding BDE #209 was only 15 ± 6 pg g(-1). Pesticide concentrations observed in the analyzed samples were generally low in comparison to maximum residue levels (MRLs) actually permitted by the European Union. However, MRLs were exceeded in 7 out of all 191 analyzed samples. Total concentration of DDT isomers in one of the tested bran samples was as high as 0.053 mg kg(-1). DMDT concentrations slightly above MRL = 0.01 mg kg(-1)were observed in 6 other samples (2 × bran, 1 × children porridge, 2 × snacks and 1 × bread). This study has shown that levels of PCBs, PBDEs and organochlorine pesticides in cereal products available on the Polish market are generally low. However, elevated levels of individual pollutants were observed in several instances. PMID:23906852

  3. Assessment of health effects in New York City firefighters after exposure to polychlorinated biphenyls (PCBs) and polychlorinated dibenzofurans (PCDFs): the Staten Island Transformer Fire Health Surveillance Project.

    PubMed

    Kelly, Kerry J; Connelly, Edmond; Reinhold, Gustave A; Byrne, Mike; Prezant, David J

    2002-01-01

    Following an electrical transformer fire in Staten Island, New York, a health surveillance program was established for 60 New York City firefighters and emergency medical technicians exposed to polychlorinated biphenyls (PCBs) and polychlorinated dibenzofurans (PCDFs). Exposure potential was documented after high levels of PCBs and PCDFs were found on transformer and firefighters' uniforms. Personnel received comprehensive medical examinations, and the results were compared with preexposure values. Serum was analyzed for PCBs, PCDFs, and polychlorinated dibenzo-p-dioxins (PCDDs). Follow-up was conducted 9 mo later. Thirty-two of 58 (55%) firefighters reported initial symptoms, and 3 firefighters required brief medical leave. Pulmonary functions, exercise performance, serum liver functions, and serum lipid profiles were normal or unchanged from preexposure baselines. Serum PCBs averaged 2.92 +/- 1.96 ppb (range = 1.9-11.0 ppb). Five (8%) had serum PCBs that were greater than or equal to 6 ppb. Eight (73%) had a significant decrease (p = .05) in serum PCB level at the time of follow-up. Serum toxic equivalency (TEQ [1998 World Health Organization]) for total PCDDs and PCDFs averaged 39.0 +/- 21.5 (n = 48). Eighteen (38%) had elevated TEQs (i.e., > 40). All firefighters had no short-term heath effects. Modern firefighting uniforms are not meant to replace HAZMAT suits, but these uniforms provide protection from this chemical exposure for most firefighters. PMID:12530594

  4. Cancer mortality among electric utility workers exposed to polychlorinated biphenyls.

    PubMed Central

    Loomis, D; Browning, S R; Schenck, A P; Gregory, E; Savitz, D A

    1997-01-01

    OBJECTIVES: To assess whether excess mortality from cancer, malignant melanoma of the skin, and cancers of the brain and liver in particular, is associated with long term occupational exposure to polychlorinated biphenyls (PCBs). METHODS: An epidemiological study of mortality was conducted among 138,905 men employed for at least six months between 1950 and 1986 at five electrical power companies in the United States. Exposures were assessed by panels composed of workers, hygienists, and managers at each company, who considered tasks performed by workers in 28 job categories and estimated weekly exposures in hours for each job. Poisson regression was used to examine mortality in relation to exposure to electrical insulating fluids containing PCBs, controlling for demographic and occupational factors. RESULTS: Neither all cause nor total cancer mortality was related to cumulative exposure to PCB insulating fluids. Mortality from malignant melanoma increased with exposure; rate ratios (RRs) relative to unexposed men for melanoma were 1.23 (95% confidence interval (95% CI) 0.56 to 2.52), 1.71 (0.68 to 4.28) and 1.93 (0.52 to 7.14) for men with < 2000, > 2000-10,000, and > 10,000 hours of cumulative exposure to PCB insulating fluids, respectively, without consideration of latency. Lagging exposure by 20 years yielded RRs of 1.29 (0.76 to 2.18), 2.56 (1.09 to 5.97), and 4.81 (1.49 to 15.50) for the same exposure levels. Mortality from brain cancer was modestly increased among men with < 2000 hours (RR 1.61, 95% CI 0.86 to 3.01) and > 2000-10,000 hours exposure (RR 1.79, 95% CI 0.81 to 3.95), but there were no deaths from brain cancer among the most highly exposed men. A lag of five years yielded slightly increased RRs. Mortality from liver cancer was not associated with exposure to PCB insulating fluids. CONCLUSIONS: This study was larger and provided more detailed information on exposure than past investigations of workers exposed to PCBs. The results suggest that PCBs

  5. Plasma polychlorinated biphenyl concentrations and immune function in postmenopausal women

    SciTech Connect

    Spector, June T.; De Roos, Anneclaire J.; Ulrich, Cornelia M.; Sheppard, Lianne; Sjoedin, Andreas; Wener, Mark H.; Wood, Brent; and others

    2014-05-01

    Background: Polychlorinated biphenyl (PCB) exposure has been associated with non-Hodgkin lymphoma in several studies, and the immune system is a potential mediator. Objectives: We analyzed associations of plasma PCBs with immune function measures. We hypothesized that higher plasma PCB concentrations are associated with lower immune function cross-sectionally, and that increases in PCB concentrations over a one year period are associated with decreases in immune function. Methods: Plasma PCB concentrations and immune function [natural killer (NK) cell cytotoxicity and PHA-induced T-lymphocyte proliferation (PHA-TLP)] were measured at baseline and one year in 109 postmenopausal overweight women participating in an exercise intervention study in the Seattle, Washington (USA) area. Mixed models, with adjustment for body mass index and other potential confounders, were used to estimate associations of PCBs with immune function cross-sectionally and longitudinally. Results: Associations of PCBs with immune function measures differed across groups of PCBs (e.g., medium- and high-chlorinated and dioxin-like [mono-ortho-substituted]) and by the time frame for the comparison (cross-sectional vs. longitudinal). Higher concentrations of medium- and high-chlorinated PCBs were associated with higher PHA-TLP cross-sectionally but not longitudinally. The mean decrease in 0.5 µg/mL PHA-TLP/50.0 pmol/g-lipid increase in dioxin-like PCBs over one year was 51.6 (95% confidence interval 2.7, 100.5; P=0.039). There was no association between plasma PCBs and NK cytotoxicity. Conclusions: These results do not provide strong evidence of impaired cellular immunity from PCB exposure. Larger longitudinal studies with greater variability in PCB exposures are needed to further examine temporal associations of PCBs with immune function. - Highlights: • Plasma PCBs and immune function were measured in 109 women at baseline and one year. • Immune measures included T lymphocyte proliferation

  6. Semiquinone Radicals from Oxygenated Polychlorinated Biphenyls: Electron Paramagnetic Resonance Studies

    PubMed Central

    2008-01-01

    Polychlorinated biphenyls (PCBs) can be oxygenated to form very reactive hydroquinone and quinone products. A guiding hypothesis in the PCB research community is that some of the detrimental health effects of some PCBs are a consequence of these oxygenated forms undergoing one-electron oxidation or reduction, generating semiquinone radicals (SQ•−). These radicals can enter into a futile redox cycle resulting in the formation of reactive oxygen species, that is, superoxide and hydrogen peroxide. Here, we examine some of the properties and chemistry of these semiquinone free radicals. Using electron paramagnetic resonance (EPR) to detect SQ•− formation, we observed that (i) xanthine oxidase can reduce quinone PCBs to the corresponding SQ•−; (ii) the heme-containing peroxidases (horseradish and lactoperoxidase) can oxidize hydroquinone PCBs to the corresponding SQ•−; (iii) tyrosinase acting on PCB ortho-hydroquinones leads to the formation of SQ•−; (iv) mixtures of PCB quinone and hydroquinone form SQ•− via a comproportionation reaction; (v) SQ•− are formed when hydroquinone-PCBs undergo autoxidation in high pH buffer (≈>pH 8); and, surprisingly, (vi) quinone-PCBs in high pH buffer can also form SQ•−; (vii) these observations along with EPR suggest that hydroxide anion can add to the quinone ring; (viii) H2O2 in basic solution reacts rapidly with PCB-quinones; and (ix) at near-neutral pH SOD can catalyze the oxidization of PCB-hydroquinone to quinone, yielding H2O2. However, using 5,5-dimethylpyrroline-1-oxide (DMPO) as a spin-trapping agent, we did not trap superoxide, indicating that generation of superoxide from SQ•− is not kinetically favorable. These observations demonstrate multiple routes for the formation of SQ•− from PCB-quinones and hydroquinones. Our data also point to futile redox cycling as being one mechanism by which oxygenated PCBs can lead to the formation of reactive oxygen species, but this is most efficient

  7. Rhodococcus biphenylivorans sp. nov., a polychlorinated biphenyl-degrading bacterium.

    PubMed

    Su, Xiaomei; Liu, Yindong; Hashmi, Muhammad Zaffar; Hu, Jinxing; Ding, Linxian; Wu, Min; Shen, Chaofeng

    2015-01-01

    A Gram-positive, aerobic, non-motile and rod-coccus shaped novel actinobacterial strain, designated as TG9(T), was isolated from a polychlorinated biphenyl (PCB)-contaminated sediment in Taizhou city, Zhejiang province, eastern China. The isolate was observed to grow at 10-45 °C (optimum 28-32 °C), pH 5.0-11.0 (optimum pH 7.0-8.0) and with 0-9.0 % (w/v) NaCl (optimum 0-3.0 %). Comparison of the 16S rRNA gene sequences of strain TG9(T) and other members of the genus Rhodococcus showed that strain TG9(T) shared highest similarities with Rhodococcus pyridinivorans DSM 44555(T) (99.4 %), R. rhodochrous DSM 43241(T) (99.2 %), R. gordoniae DSM 44689(T) (99.2 %) and R. artemisiae DSM 45380(T) (98.2 %). However, low levels of DNA-DNA relatedness (15-48 %), which are below the 70 % limit for prokaryotic species identification, were obtained by DNA-DNA hybridization. Strain TG9(T) was found to contain meso-diaminopimelic acid as the diagnostic diamino acid and arabinose and galactose in the whole-cell hydrolysate. Mycolic acids were found to be present. The major fatty acids were identified as C16:0, C16:1 ω7c and/or iso-C15:0 2-OH, 10-methyl C18:0 and C18:1 ω9c. The only menaquinone detected was MK-8 (H2). The major polar lipids detected were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, glycolipid and traces of some unknown lipids. The genomic DNA G+C content of strain TG9(T) was determined to be 62.8 %. The combined phenotypic and genotypic data show that the strain represents a novel species of the genus Rhodococcus for which the name Rhodococcus biphenylivorans sp. nov. is proposed, with the type strain TG9(T) (=CGMCC 1.12975(T) = KCTC 29673(T) = MCCC 1K00286(T)). PMID:25315102

  8. Lactational transfer of mercury and polychlorinated biphenyls in polar bears.

    PubMed

    Knott, Katrina K; Boyd, Daryle; Ylitalo, Gina M; O'Hara, Todd M

    2012-07-01

    We examined concentrations of total mercury (tHg, inorganic and methylated forms) and polychlorinated biphenyls (PCBs) in blood and milk from free-ranging Southern Beaufort-Chukchi Sea polar bears (Ursus maritimus) to assess maternal transfer of contaminants during lactation and the potential health risk to nursing young. Concentrations of contaminants in the blood of dependent and juvenile animals (ages 1-5 years) ranged from 35.9 to 52.2 μg kg(-1) ww for tHg and 13.9 to 52.2 μg kg(-1) ww (3255.81-11067.79 μg kg(-1) lw) for ΣPCB(7)s, similar to those of adult females, but greater than adult males. Contaminant concentrations in milk ranged from 5.7 to 71.8 μg tHg kg(-1)ww and 160 to 690 μg ΣPCB(11)s kg(-1) ww (547-5190 μg kg(-1) lw). The daily intake levels for tHg by milk consumption estimated for dependent young were below the tolerable daily intake level (TDIL) of tHg established for adult humans. Although the daily intake levels of PCBs through milk consumption for cubs of the year exceeded the TDIL thresholds, calculated dioxin equivalents for PCBs in milk were below adverse physiological thresholds for aquatic mammals. Relatively high concentrations of non-dioxin like PCBs in polar bear milk and blood could impact endocrine function of Southern Beaufort-Chukchi Sea polar bears, but this is uncertain. Transfer of contaminants during mid to late lactation likely limits bioaccumulation of dietary contaminants in female polar bears during spring. As polar bears respond to changes in their arctic sea ice habitat, the adverse health impacts associated with nutritional stress may be exacerbated by tHg and PCBs exposure, especially in ecologically and toxicologically sensitive polar bear cohorts such as reproductive females and young. PMID:22464860

  9. MONITORING POLYCHLORINATED BIPHENYLS (PCBS) BIODEGRADATION USING CONTINUOUS-FLOW ISOTOPE RATIO MASS SPECTROMETRY

    EPA Science Inventory

    Research has shown that polychlorinated biphenyls (PCBs) in some cases can be removed from the environment by biodegradation. Aerobic and anaerobic biological processes have been determined in previous research to be capable of degrading PCBs. During the aerobic and anaerobic d...

  10. ORIGIN OF CARBON IN POLYCHLORINATED DIOXINS AND FURANS FORMED DURING SOOTING COMBUSTION

    EPA Science Inventory

    The paper discusses results of an investigation on the importance of solid- and gas-phase carbon precursors for the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/Fs) during sooting combustion. Experiments were performed in an entrained flow reactor (EFR)...