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Sample records for biphenyl mixture aroclor

  1. Gender-dependent behavioral and sensory effects of a commercial mixture of polychlorinated biphenyls (Aroclor 1254) in rats.

    Science.gov (United States)

    Geller, A M; Oshiro, W M; Haykal-Coates, N; Kodavanti, P R; Bushnell, P J

    2001-02-01

    Developmental exposure to polychlorinated biphenyls (PCBs) has been associated with behavioral and cognitive deficits in humans and animal models. Perinatal exposure to PCBs has also been associated with sensory deficits in animal models. These effects were hypothesized to be mediated in part by ortho-substituted PCBs, which do not or weakly bind to the aryl hydrocarbon (Ah) receptor. The present studies were designed to determine whether perinatal exposure to Aroclor 1254, a commercial mixture of > 99% ortho-substituted PCBs, would affect cognitive and sensory function in Long-Evans rats. Adult male and female offspring of female rats fed Aroclor 1254 (Lot #124-191; doses of 0, 1, or 6 mg/kg/day; gestational day 6 through postnatal day 21; n = eight/group) were trained to perform a signal detection task capable of assessing sensory thresholds. Training included autoshaping and operant conditioning. Thresholds for detecting a 1-s light stimulus were determined under background illuminations ranging from 2 lux to complete darkness. Female rats exposed to Aroclor 1254 autoshaped more rapidly than control females, at a rate akin to control males. Control females had lower thresholds than control males at all levels of background illumination. These differences were abolished by Aroclor 1254, which reduced thresholds in males and increased thresholds in females. These data extend previous findings of gender-specific effects of PCBs on neurobehavioral development to measures of acquisition and sensory function.

  2. Influence of Aroclor 1242 Concentration on Polychlorinated Biphenyl Biotransformations in Hudson River Test Tube Microcosms

    Science.gov (United States)

    Fish, K. M.

    1996-01-01

    When 93.3 to 933 (mu)mol of Aroclor 1242 per kg was added to Hudson River sediment test tube microcosms, the rates of polychlorinated biphenyl biotransformations increased with increasing Aroclor 1242 concentration after a 4- to 8-week acclimation period. In contrast, when 37.3 (mu)mol of Aroclor 1242 per kg was added, polychlorinated biphenyl biotransformations occurred at slow constant rates. PMID:16535387

  3. Reproductive dysfunction in rhesus monkeys exposed to low levels of polychlorinated biphenyls (Aroclor 1248)

    Energy Technology Data Exchange (ETDEWEB)

    Barsotti, D.A.; Marlar, R.J.; Allen, J.R.

    1976-01-01

    Eighteen female and four male adult Rhesus monkeys were fed the polychlorinated biphenyl (PCB) Aroclor 1248 at levels of either 2.5 or 5.0 ppM in the diet. These levels are equal to, and 50% of, the concentration allowed in certain foods destined for human consumption. After consuming these diets for 2 months, some of the females developed acne, alopecia, erythema and swelling of the eyelids, and by 6 months all females exhibited these changes to some degree. Modifications in serum lipids developed gradually, with a trend towards hypocholesterolaemia, hypolipidaemia and decreased serum triglycerides. In addition there was a shift in the plasma albumin/globulin ratio and an increase in serum glutamic-pyruvic transaminase activity. Analysis of subcutaneous fat showed an accumulation of the PCB isomers in the adipose tissue. The concentrations in this tissue reached a plateau, after which only slight variations were observed. Within 4 months, menstrual cycles were altered: menostaxis and menorrhagia occurred frequently and at times amenorrhoea was apparent. The ability of the animals to maintain pregnancy was impaired, as indicated by frequent resorptions and abortions. When infants were born they were small, and the transplacental movement of PCBs was evident from analyses of skin biopsies of neonates and of autopsy tissue from one stillborn. Moreover, additional accumulation of PCBs occurred in infants during breast feeding. All males fed 5.0 ppM PCB exhibited only slight periorbital oedema and erythema after 14 months on the diet and showed no alterations in their breeding capacities. The data presented indicate that long-term, low-level exposure of female non-human primates to PCBs can affect many important biological parameters.

  4. Mucinous gastric hyperplasia in a colony of rhesus monkeys (Macaca mulatta) induced by polychlorinated biphenyl (Aroclor 1254)

    Energy Technology Data Exchange (ETDEWEB)

    Geistfeld, J.G.; Bond, M.G.; Bullock, B.C.; Varian, M.C.

    1982-02-01

    Since 1971, 45 of 259 male rhesus monkeys housed in a primate building have died of a chronic and progressive disease characterized by diarrhea, dehydration, weakness, gingivitis, emaciation, and alopecia. The principal necropsy finding in these monkeys, and in eight others killed for experimental purposes, was hypertrophic and hyperplastic mucinous gastropathy involving both the mucosa and submucosa. The toxic agent involved was identified as the polychlorinated biphenyl (PCB), Aroclor 1254. The suspected source of the toxic agent was a concrete sealer used during building construction.

  5. Biochemical effects of an environmental chlorofen mixture in comparison with aroclor 1254 in rats

    Energy Technology Data Exchange (ETDEWEB)

    Kania-Korwel, I.; Ludewig, G.; Robertson, L.W.; Lehmler, H.J. [Dept. of Occupational and Environmental Health, Univ. of Iowa, Iowa City (United States); Hornbuckle, K.C.; Peck, A. [Dept. of Civil and Environmental Engineering, Univ. of Iowa, Iowa City (United States); Espandiari, P.; C. Gary Gairola [Graduate Center for Toxicology, Univ. of Kentucky, Lexington (United States); Sulkowski, W.W. [Dept. of Environmental Chemistry and Technology, Univ. of Silesia, Katowice (Poland)

    2004-09-15

    To our knowledge no in vivo mammalian toxicity studies with Chlorofen or environmental mixtures from Chlorofen contaminated sites have been performed. The present study investigates the biological effects in male rats of a soil-extract from a highly contaminated soil from the Chlorofen manufacturing site. The congener profile of this soil extract is very similar to Chlorofen although some lower chlorinated congeners are present, probably because of biodegradation or atmospheric deposition. The biological effect was compared with Aroclor 1254. The total PCB levels as well as the PCB congener profile in the liver were also determined to allow a better understanding of the effects of the two different mixtures on relevant liver enzymes.

  6. Effects of Aroclor 1254 on in vivo oocyte maturation in the mouse.

    Directory of Open Access Journals (Sweden)

    ShuZhen Liu

    Full Text Available Polychlorinated biphenyls (PCBs are stable, lipophilic compounds that accumulate in the environment and in the food chain. Though some studies provided evidence that PCBs had adverse effects on reproductive function, most of these results were from in vitro models. Therefore we investigated the effect of Aroclor 1254 (a commercial PCBs mixture treatments on in vivo maturation and developmental potential of mouse oocytes. In the present study, female ICR mice were treated with different doses (12.5, 25 and 50 mg/kg of Aroclor 1254 (a commercial PCB mixture once every 72 hours by intraperitoneal injection for 9 days. After three treatments of Aroclor 1254, the mice were superovulated to collect oocytes one day after the last exposure. The effects of Aroclor 1254 on oocyte maturation, fertilization, and preimplantation embryonic development were investigated. Immunofluorescence-stained oocytes were observed under a confocal microscope to assess the effects of Aroclor 1254 on spindle morphology. Parthenogenic activation and the incidence of cumulus apoptosis in cumulus-oocyte complexes were observed as well. Oocytes exposed to different doses of Aroclor 1254 in vivo were associated with a significant decrease in outgrowth potential, abnormal spindle configurations, and the inhibition of parthenogenetic activation of ovulated oocytes. Furthermore, the incidence of apoptosis in cumulus cells was increased after exposed to Aroclor 1254. These results may provide reference for the treatment of reproductive diseases such as infertility or miscarriage caused by environmental contaminants.

  7. Dietary exposure to the PCB mixture aroclor 1254 may compromise osmoregulation by altering central vasopressin release

    Energy Technology Data Exchange (ETDEWEB)

    Coburn, C G [Environmental Toxicology, Univ. of California at Riverside, CA (United States); Gillard, E; Curras-Collazo, M [Cell Biology and Neuroscience, Univ. of California at Riverside, CA (United States)

    2004-09-15

    Despite the importance of systemic osmoregulation, the potential deleterious effects of persistent organochlorines, such as polychlorinated biphenyls (PCBs), on body fluid regulation has not been thoroughly investigated. In an effort to ameliorate this deficit, the current study explores the toxic effects of PCBs on osmoregulation, and in particular, on the activity of the magnocellular neuroendocrine cell (MNC) system of the hypothalamus. MNCs of the supraoptic nucleus (SON) release oxytocin (OXY) and vasopressin (VP) from terminals in the neurohypophysis in response to dehydration. The latter is released to effect water conservation in response to dehydration via its action upon the kidney and through extra-renal actions. MNCs also secrete VP from their cell bodies and dendrites locally i.e., into the extracellular space of the SON. Although it has been shown that both intranuclear and systemic release rise in response to dehydration the physiological significance of intranuclear release has not been fully elucidated. We chose to use voluntary ingestion as the route of PCB exposure since it is more reflective of natural exposure compared to ip injection. One unexpected observation that resulted from pilot studies using ip injection of PCBs was the deleterious effects of the vehicle (corn oil) resulting in pooling of lipid within the abdominal cavity, mottling of the liver, fatty liver and general discoloration of all abdominal viscera at time of sacrifice. Therefore, all work described in this series of experiments have employed voluntary ingestion of the toxin. Work described in this paper suggests that PCBs in concentrations reflecting realistic lifetime exposure levels may negatively impact homeostatic mechanisms responsible for body water balance by altering somatodendritic (intranuclear) VP secretion in response to dehydration in vivo. The downstream consequences of such influence is currently under investigation, and preliminary evidence suggests that the

  8. Effects of Aroclor 1254 on dopamine and norepinephrine concentrations in pheochromocytoma (PC-12) cells

    International Nuclear Information System (INIS)

    Seegal, R.F.; Brosch, K.; Bush, B.; Ritz, M.; Shain, W.

    1990-01-01

    Pheochromocytoma (PC-12) cells synthesize, store, release and metabolize dopamine (DA) and norepinephrine (NE) in a manner analogous to that observed in the mammalian central nervous system. These cells were used to develop and validate an alternate method to animal testing to assess the effects of a complex environmental mixture of polychlorinated biphenyls (Aroclor 1254) on cellular catecholamine function. Aroclor 1254, at concentrations of 1 to 100 ppm, significantly decreased cellular catecholamine concentrations after 6 hrs. Exposure at 100 ppm for periods of less than an hr increased cellular catecholamine concentrations while longer exposure times (i.e., 1 to 24 hr) decreased cellular catecholamine concentrations. This in vitro depletion of catecholamines is similar to that seen in vivo. Thus, PC-12 cells may be useful for neurochemical evaluation of neurotoxicants with particular reference to effects on catecholaminergic systems

  9. Disruption of the thyroid system by the thyroid-disrupting compound Aroclor 1254 in juvenile Japanese flounder (Paralichthys olivaceus.

    Directory of Open Access Journals (Sweden)

    Yifei Dong

    Full Text Available Polychlorinated biphenyls (PCBs are a group of persistent organochlorine compounds that have the potential to disrupt the homeostasis of thyroid hormones (THs in fish, particularly juveniles. In this study, thyroid histology, plasma TH levels, and iodothyronine deiodinase (IDs, including ID1, ID2, and ID3 gene expression patterns were examined in juvenile Japanese flounder (Paralichthys olivaceus following 25- and 50-day waterborne exposure to environmentally relevant concentrations of a commercial PCB mixture, Aroclor 1254 (10, 100, and 1000 ng/L with two-thirds of the test solutions renewed daily. The results showed that exposure to Aroclor 1254 for 50 d increased follicular cell height, colloid depletion, and hyperplasia. In particular, hypothyroidism, which was induced by the administration of 1000 ng/L Aroclor 1254, significantly decreased plasma TT4, TT3, and FT3 levels. Profiles of the changes in mRNA expression levels of IDs were observed in the liver and kidney after 25 and 50 d PCB exposure, which might be associated with a reduction in plasma THs levels. The expression level of ID2 mRNA in the liver exhibited a dose-dependent increase, indicating that this ID isotype might serve as sensitive and stable indicator for thyroid-disrupting chemical (TDC exposure. Overall, our study confirmed that environmentally relevant concentrations of Aroclor 1254 cause significant thyroid disruption, with juvenile Japanese flounder being suitable candidates for use in TDC studies.

  10. Evaluation of Aroclor 1260 exposure in a mouse model of diet-induced obesity and non-alcoholic fatty liver disease

    International Nuclear Information System (INIS)

    Wahlang, Banrida; Song, Ming; Beier, Juliane I.; Cameron Falkner, K.; Al-Eryani, Laila; Clair, Heather B.; Prough, Russell A.; Osborne, Tanasa S.; Malarkey, David E.; Christopher States, J.; Cave, Matthew C.

    2014-01-01

    Polychlorinated biphenyls (PCBs) are persistent organic pollutants associated with non-alcoholic fatty liver disease (NAFLD) in epidemiologic studies. The purpose of this study was to evaluate the hepatic effects of a PCB mixture, Aroclor 1260, whose composition mimics human bioaccumulation patterns, in a mouse model of diet-induced obesity (DIO). Male C57Bl/6J mice were fed control diet or 42% high fat diet (HFD) and exposed to Aroclor 1260 (20 mg/kg or 200 mg/kg in corn oil) for 12 weeks. A glucose tolerance test was performed; plasma/tissues were obtained at necropsy for measurements of adipocytokine levels, histology, and gene expression. Aroclor 1260 exposure was associated with decreased body fat in HFD-fed mice but had no effect on blood glucose/lipid levels. Paradoxically, Aroclor 1260 + HFD co-exposed mice demonstrated increased hepatic inflammatory foci at both doses while the degree of steatosis did not change. Serum cytokines, ALT levels and hepatic expression of IL-6 and TNFα were increased only at 20 mg/kg, suggesting an inhibition of pro-inflammatory cytokine production at the 200 mg/kg exposure. Aroclor 1260 induced hepatic expression of cytochrome P450s including Cyp3a11 (Pregnane-Xenobiotic Receptor target) and Cyp2b10 (constitutive androstane receptor target) but Cyp2b10 inducibility was diminished with HFD-feeding. Cyp1a2 (aryl hydrocarbon Receptor target) was induced only at 200 mg/kg. In summary, Aroclor 1260 worsened hepatic and systemic inflammation in DIO. The results indicated a bimodal response of PCB-diet interactions in the context of inflammation which could potentially be explained by xenobiotic receptor activation. Thus, PCB exposure may be a relevant “second hit” in the transformation of steatosis to steatohepatitis. - Highlights: • Aroclor 1260 exposure decreased adiposity in mice fed with high fat diet • Aroclor 1260 exposure induced steatohepatitis in diet-induced obese mice • Aroclor 1260 (20 and 200 mg/kg) induced

  11. Evaluation of Aroclor 1260 exposure in a mouse model of diet-induced obesity and non-alcoholic fatty liver disease

    Energy Technology Data Exchange (ETDEWEB)

    Wahlang, Banrida [Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY 40202 (United States); Song, Ming [Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, University of Louisville School of Medicine, Louisville, KY 40202 (United States); Beier, Juliane I. [Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY 40202 (United States); Cameron Falkner, K. [Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, University of Louisville School of Medicine, Louisville, KY 40202 (United States); Al-Eryani, Laila [Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY 40202 (United States); Clair, Heather B.; Prough, Russell A. [Department of Biochemistry and Molecular Biology, University of Louisville School of Medicine, Louisville, KY 40202 (United States); Osborne, Tanasa S.; Malarkey, David E. [Cellular and Molecular Pathology Branch, National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 (United States); Christopher States, J. [Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY 40202 (United States); Cave, Matthew C., E-mail: matt.cave@louisville.edu [Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY 40202 (United States); Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, University of Louisville School of Medicine, Louisville, KY 40202 (United States); The Robley Rex Veterans Affairs Medical Center, Louisville, KY 40206 (United States)

    2014-09-15

    Polychlorinated biphenyls (PCBs) are persistent organic pollutants associated with non-alcoholic fatty liver disease (NAFLD) in epidemiologic studies. The purpose of this study was to evaluate the hepatic effects of a PCB mixture, Aroclor 1260, whose composition mimics human bioaccumulation patterns, in a mouse model of diet-induced obesity (DIO). Male C57Bl/6J mice were fed control diet or 42% high fat diet (HFD) and exposed to Aroclor 1260 (20 mg/kg or 200 mg/kg in corn oil) for 12 weeks. A glucose tolerance test was performed; plasma/tissues were obtained at necropsy for measurements of adipocytokine levels, histology, and gene expression. Aroclor 1260 exposure was associated with decreased body fat in HFD-fed mice but had no effect on blood glucose/lipid levels. Paradoxically, Aroclor 1260 + HFD co-exposed mice demonstrated increased hepatic inflammatory foci at both doses while the degree of steatosis did not change. Serum cytokines, ALT levels and hepatic expression of IL-6 and TNFα were increased only at 20 mg/kg, suggesting an inhibition of pro-inflammatory cytokine production at the 200 mg/kg exposure. Aroclor 1260 induced hepatic expression of cytochrome P450s including Cyp3a11 (Pregnane-Xenobiotic Receptor target) and Cyp2b10 (constitutive androstane receptor target) but Cyp2b10 inducibility was diminished with HFD-feeding. Cyp1a2 (aryl hydrocarbon Receptor target) was induced only at 200 mg/kg. In summary, Aroclor 1260 worsened hepatic and systemic inflammation in DIO. The results indicated a bimodal response of PCB-diet interactions in the context of inflammation which could potentially be explained by xenobiotic receptor activation. Thus, PCB exposure may be a relevant “second hit” in the transformation of steatosis to steatohepatitis. - Highlights: • Aroclor 1260 exposure decreased adiposity in mice fed with high fat diet • Aroclor 1260 exposure induced steatohepatitis in diet-induced obese mice • Aroclor 1260 (20 and 200 mg/kg) induced

  12. Induction of monooxygenation in rainbow trout by polybrominated biphenyls: a comparative study.

    Science.gov (United States)

    Elcombe, C R; Lech, J J

    1978-01-01

    Two commercial polychlorinated biphenyl mixtures (Aroclor 1254 and Aroclor 1242) and one polybrominated biphenyl mixture (FireMaster BP-6) were examined for their abilities to induce hepatic microsomal monooxygenation in rainbow trout (Salmo gairdneri). Pretreatment of rainbow trout with Aroclors 1254 and 1242 (150 mg/kg IP) resulted in an approximate 10-fold induction of arylhydrocarbon (benzo[a]pyrene) hydroxylation, ethoxycoumarin-O-deethylation and ethoxyresorufin-O-deethylation within 7 days after injection. These enzyme activities remained elevated above control values for at least 2-3 weeks. Administration of FireMaster BP-6 (150 mg/kg IP) also resulted in an induction of several monooxygenase activities. Arylhydrocarbon (benzo[a]pyrene) hydroxylation, ethoxycoumarin-O-deethylation and ethoxyresorufin-O-deethylation were increased by 6-, 3,- and 25-fold, respectively. Only the latter two activities remained elevated two weeks post-injection. Ethylmorphine-N-demethylation was unaffected by the polyhalogenated biphenyls. Significant increases in P-450 hemoprotein were not observed after pretreatment with any of the polyhalogenated biphenyls studied. PMID:209992

  13. Polychlorinated biphenyls alter expression of alpha-synuclein, synaptophysin and parkin in the rat brain

    DEFF Research Database (Denmark)

    Malkiewicz, Katarzyna; Mohammed, Roma; Folkesson, Ronnie

    2006-01-01

    Polychlorinated Biphenyls (PCBs)-induced changes in synaptic transmission are one of the effects of their neurotoxicity but the mechanism remains unknown. We assessed the in vivo effects of the PCBs mixture, Aroclor 1254 on the expression of neuronal proteins that are involved in the synaptic...... function and/or are associated with neurodegeneration. Wistar rats were treated orally with repeated doses of Aroclor 1254 and the levels of soluble alpha-synuclein, parkin, synaptophysin and amyloid precursor protein (APP) in the brain were determined by Western blotting. The results showed that Aroclor...... did not cause changes in the expression and processing of APP but at a dose 100 microg/g/day repeated for 6 days caused a decrease in the expression of alpha-synuclein in the cerebellum, cortex, hippocampus and hypothalamus of the animals sacrificed 2 days after treatment. The decrease in alpha...

  14. Aroclor 1254, a developmental neurotoxicant, alters energy metabolism- and intracellular signaling-associated protein networks in rat cerebellum and hippocampus

    International Nuclear Information System (INIS)

    Kodavanti, Prasada Rao S.; Osorio, Cristina; Royland, Joyce E.; Ramabhadran, Ram; Alzate, Oscar

    2011-01-01

    The vast literature on the mode of action of polychlorinated biphenyls (PCBs) indicates that PCBs are a unique model for understanding the mechanisms of toxicity of environmental mixtures of persistent chemicals. PCBs have been shown to adversely affect psychomotor function and learning and memory in humans. Although the molecular mechanisms for PCB effects are unclear, several studies indicate that the disruption of Ca 2+ -mediated signal transduction plays significant roles in PCB-induced developmental neurotoxicity. Culminating events in signal transduction pathways include the regulation of gene and protein expression, which affects the growth and function of the nervous system. Our previous studies showed changes in gene expression related to signal transduction and neuronal growth. In this study, protein expression following developmental exposure to PCB is examined. Pregnant rats (Long Evans) were dosed with 0.0 or 6.0 mg/kg/day of Aroclor-1254 from gestation day 6 through postnatal day (PND) 21, and the cerebellum and hippocampus from PND14 animals were analyzed to determine Aroclor 1254-induced differential protein expression. Two proteins were found to be differentially expressed in the cerebellum following PCB exposure while 18 proteins were differentially expressed in the hippocampus. These proteins are related to energy metabolism in mitochondria (ATP synthase, sub unit β (ATP5B), creatine kinase, and malate dehydrogenase), calcium signaling (voltage-dependent anion-selective channel protein 1 (VDAC1) and ryanodine receptor type II (RyR2)), and growth of the nervous system (dihydropyrimidinase-related protein 4 (DPYSL4), valosin-containing protein (VCP)). Results suggest that Aroclor 1254-like persistent chemicals may alter energy metabolism and intracellular signaling, which might result in developmental neurotoxicity. -- Highlights: ► We performed brain proteomic analysis of rats exposed to the neurotoxicant, Aroclor 1254. ► Cerebellum and

  15. Gene expression profiles in the cerebellum and hippocampus following exposure to a neurotoxicant, Aroclor 1254: Developmental effects

    International Nuclear Information System (INIS)

    Royland, Joyce E.; Wu, Jinfang; Zawia, Nasser H.; Kodavanti, Prasada Rao S.

    2008-01-01

    The developmental consequences of exposure to the polychlorinated biphenyls (PCBs) have been widely studied, making PCBs a unique model to understand issues related to environmental mixture of persistent chemicals. PCB exposure in humans adversely affects neurocognitive development, causes psychomotor difficulties, and contributes to attention deficits in children, all of which seem to be associated with altered patterns of neuronal connectivity. In the present study, we examined gene expression profiles in the rat nervous system following PCB developmental exposure. Pregnant rats (Long-Evans) were dosed perinatally with 0 or 6 mg/kg/day of Aroclor 1254 from gestation day 6 through postnatal day (PND) 21. Gene expression in cerebellum and hippocampus from PND7 and PND14 animals was analyzed with an emphasis on developmental aspects. Changes in gene expression (≥ 1.5 fold) in control animals identified normal developmental changes. These basal levels of expression were compared to data from Aroclor 1254-treated animals to determine the impact of gestational PCB exposure on developmental parameters. The results indicate that the expression of a number of developmental genes related to cell cycle, synaptic function, cell maintenance, and neurogenesis is significantly altered from PND7 to PND14. Aroclor 1254 treatment appears to dampen the overall growth-related gene expression levels in both regions with the effect being more pronounced in the cerebellum. Functional analysis suggests that Aroclor 1254 delays maturation of the developing nervous system, with the consequences dependent on the ontological state of the brain area and the functional role of the individual gene. Such changes may underlie learning and memory deficits observed in PCB exposed animals and humans

  16. Analysis the mixtures of polyphenyls by gas chromatrogaphie. 1.- Area response for biphenyl and terphenyls relative to triphenylmethane

    International Nuclear Information System (INIS)

    Perez Garcia, M.

    1966-01-01

    The relative performances of the thermal conductivity and flame ionization detectors towards triphenylmethane were investigated for each one of the components of biphenyl of biphenyl and terphenyl mixtures. The influence of the concentration of the considered compound as well as the influence derived from the present of all other components on the above-mentioned relative performance were studied. A 2 m long column filled with 50-70 mesh stomacher containing 20% apiezon L was used to carry out the study with the thermal conductivity detector by keeping the column at 300 degree centigree using helium gas as carrier. (Author) 13 refs

  17. Decomposition of polychlorinated biphenyls in soil with a dispersion mixture of metallic calcium and calcium oxide.

    Science.gov (United States)

    Mitoma, Yoshiharu; Mallampati, Srinivasa Reddy; Miyata, Hideaki; Kakeda, Mitsunori

    2013-02-01

    This study describes the decomposition of polychlorinated biphenyls (PCBs) in soil with dispersion mixtures of metallic calcium (Ca) and calcium oxide (CaO) at different temperatures. In these experiments, naturally moisturized and contaminated soil (1.0 g [31 ppm PCBs]), CaO (dried 2.0 wt%), and metallic Ca (0.01 g [0.25 mmol]) were introduced into a stainless steel pressure reactor under 0.1 MPa N(2) gas. The mixtures were stirred magnetically and heated at 260, 280, and 300 °C, respectively. Soil treatment with metallic Ca and CaO under various temperature conditions is extremely effective for degrading existing PCBs. Decomposition resulted from dechlorination (DC). Initial moisture in soil acted as a hydrogen source during stirring. Soil moisture can be beneficial for hydrodechlorination in the presence of metallic Ca and CaO. Furthermore, metallic Ca and CaO can greatly increase the number of collisions and mutual refinement. Treatment at 260, 280, and 300 °C combined with metallic Ca and CaO is effective for the decomposition (approximately 95 % DC) of PCBs in soil under natural moisture conditions.

  18. Production of metabolites from chloro biphenyls by resting cells of Pseudomonas strain LB400 after growth on different carbon sources

    International Nuclear Information System (INIS)

    Billingsley, K.A.; Ward, O.P.

    1999-01-01

    The transformation of polychlorinated biphenyl (PCB), when exposed to microorganisms, into chlorobenzoic acid metabolites was studied. PCBs are widely used in electrical transformers and have become widely dispersed in the environment. A proposed system for clean up of PCBs involves the combined use of anaerobic reductive dehalogenation of highly chlorinated congeners followed by aerobic degradation of moderately chlorinated PCBs, mediated by oxidative ring attack. Much of this work focused on biphenyl-grown cells, in particular Pseudomonas strain LB400 grown on biphenyl, which contains a multicomponent enzyme system. It was shown that resting cells of Pseudomonas strain LB400, grown on glycerol or glucose, could also transform purified PCB congeners and mixtures of PCBs in Aroclors, however, transformation rates were less than those observed with biphenyl-grown cells. 29 refs., 2 tabs., 2 figs

  19. Effects of Quercetin on CYP450 and Cytokines in Aroclor 1254 Injured Endometrial Cells of the Pregnant Rats

    Directory of Open Access Journals (Sweden)

    Lina Xu

    2014-01-01

    Full Text Available Polychlorinated biphenyls (PCBs are widespread persistent residual environmental pollutants, which affect seriously the growth and reproductive alterations in humans and animals. Aroclor 1254 is a commercial mixture of PCBs. Quercetin is a flavonoid, which acts on estrogen receptors and causes the development of estrogen-related diseases. In this paper, the primary cultured endometrial cells in the pregnant rats were isolated and Aroclor 1254 was used to induce the injured endometrial cells model. The cells were treated with gradient quercetin, the viability of the endometrial cells, the expressions of CYP450, the contents of TNF-α, IL-6, estradiol (E2, and progesterone (P4 were measured. It showed that the viability of the cultured endometrial cells, the expression of CYP1A1 and CYP2B1, and the contents of TNF-α, E2, and IL-6 in the injured endometrial cells increased with the treatment of quercetin. It shows that quercetin has protective effect on the injured endometrial cells in the pregnant rats, this provide a basis on herbal medicine protection for animal reproductive diseases caused by environmental endocrine disruptors.

  20. Polychlorinated Biphenyl-Xenobiotic Nuclear Receptor Interactions Regulate Energy Metabolism, Behavior, and Inflammation in Non-alcoholic-Steatohepatitis.

    Science.gov (United States)

    Wahlang, Banrida; Prough, Russell A; Falkner, K Cameron; Hardesty, Josiah E; Song, Ming; Clair, Heather B; Clark, Barbara J; States, J Christopher; Arteel, Gavin E; Cave, Matthew C

    2016-02-01

    Polychlorinated biphenyls (PCBs) are environmental pollutants associated with non-alcoholic-steatohepatitis (NASH), diabetes, and obesity. We previously demonstrated that the PCB mixture, Aroclor 1260, induced steatohepatitis and activated nuclear receptors in a diet-induced obesity mouse model. This study aims to evaluate PCB interactions with the pregnane-xenobiotic receptor (Pxr: Nr1i2) and constitutive androstane receptor (Car: Nr1i3) in NASH. Wild type C57Bl/6 (WT), Pxr(-/-) and Car(-/-) mice were fed the high fat diet (42% milk fat) and exposed to a single dose of Aroclor 1260 (20 mg/kg) in this 12-week study. Metabolic phenotyping and analysis of serum, liver, and adipose was performed. Steatohepatitis was pathologically similar in all Aroclor-exposed groups, while Pxr(-/-) mice displayed higher basal pro-inflammatory cytokine levels. Pxr repressed Car expression as evident by increased basal Car/Cyp2b10 expression in Pxr(-/-) mice. Both Pxr(-/-) and Car(-/-) mice showed decreased basal respiratory exchange rate (RER) consistent with preferential lipid metabolism. Aroclor increased RER and carbohydrate metabolism, associated with increased light cycle activity in both knockouts, and decreased food consumption in the Car(-/-) mice. Aroclor exposure improved insulin sensitivity in WT mice but not glucose tolerance. The Aroclor-exposed, Pxr(-/-) mice displayed increased gluconeogenic gene expression. Lipid-oxidative gene expression was higher in WT and Pxr(-/-) mice although RER was not changed, suggesting PCB-mediated mitochondrial dysfunction. Therefore, Pxr and Car regulated inflammation, behavior, and energy metabolism in PCB-mediated NASH. Future studies should address the 'off-target' effects of PCBs in steatohepatitis. Published by Oxford University Press on behalf of the Society of Toxicology 2015. This work is written by US Government employees and is in the public domain in the US.

  1. Chemometric comparison of polychlorinated biphenyl residues and toxicologically active polychlorinated biphenyl congeners in the eggs of Forster's Terns (Sterna fosteri)

    Science.gov (United States)

    Schwartz, Ted R.; Stalling, David L.

    1991-01-01

    The separation and characterization of complex mixtures of polychlorinated biphenyls (PCBs) is approached from the perspective of a problem in chemometrics. A technique for quantitative determination of PCB congeners is described as well as an enrichment technique designed to isolate only those congener residues which induce mixed aryl hydrocarbon hydroxylase enzyme activity. A congener-specific procedure is utilized for the determination of PCBs in whichn-alkyl trichloroacetates are used as retention index marker compounds. Retention indices are reproducible in the range of ±0.05 to ±0.7 depending on the specific congener. A laboratory data base system developed to aid in the editing and quantitation of data generated from capillary gas chromatography was employed to quantitate chromatographic data. Data base management was provided by computer programs written in VAX-DSM (Digital Standard MUMPS) for the VAX-DEC (Digital Equipment Corp.) family of computers.In the chemometric evaluation of these complex chromatographic profiles, data are viewed from a single analysis as a point in multi-dimensional space. Principal Components Analysis was used to obtain a representation of the data in a lower dimensional space. Two-and three-dimensional proections based on sample scores from the principal components models were used to visualize the behavior of Aroclor® mixtures. These models can be used to determine if new sample profiles may be represented by Aroclor profiles. Concentrations of individual congeners of a given chlorine substitution may be summed to form homologue concentration. However, the use of homologue concentrations in classification studies with environmental samples can lead to erroneous conclusions about sample similarity. Chemometric applications are discussed for evaluation of Aroclor mixture analysis and compositional description of environmental residues of PCBs in eggs of Forster's terns (Sterna fosteri) collected from colonies near Lake Poygan

  2. Aroclor 1254, a developmental neurotoxicant, alters energy metabolism- and intracellular signaling-associated protein networks in rat cerebellum and hippocampus

    Energy Technology Data Exchange (ETDEWEB)

    Kodavanti, Prasada Rao S., E-mail: kodavanti.prasada@epa.gov [Neurotoxicology Branch, NHEERL, ORD, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina (United States); Osorio, Cristina [Systems Proteomics Center, University of North Carolina at Chapel Hill, North Carolina (United States); Program on Molecular Biology and Biotechnology, University of North Carolina at Chapel Hill, North Carolina (United States); Royland, Joyce E.; Ramabhadran, Ram [Genetic and Cellular Toxicology Branch, NHEERL, ORD, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina (United States); Alzate, Oscar [Department of Cellular and Developmental Biology, University of North Carolina at Chapel Hill, North Carolina (United States); Systems Proteomics Center, University of North Carolina at Chapel Hill, North Carolina (United States); Program on Molecular Biology and Biotechnology, University of North Carolina at Chapel Hill, North Carolina (United States)

    2011-11-15

    The vast literature on the mode of action of polychlorinated biphenyls (PCBs) indicates that PCBs are a unique model for understanding the mechanisms of toxicity of environmental mixtures of persistent chemicals. PCBs have been shown to adversely affect psychomotor function and learning and memory in humans. Although the molecular mechanisms for PCB effects are unclear, several studies indicate that the disruption of Ca{sup 2+}-mediated signal transduction plays significant roles in PCB-induced developmental neurotoxicity. Culminating events in signal transduction pathways include the regulation of gene and protein expression, which affects the growth and function of the nervous system. Our previous studies showed changes in gene expression related to signal transduction and neuronal growth. In this study, protein expression following developmental exposure to PCB is examined. Pregnant rats (Long Evans) were dosed with 0.0 or 6.0 mg/kg/day of Aroclor-1254 from gestation day 6 through postnatal day (PND) 21, and the cerebellum and hippocampus from PND14 animals were analyzed to determine Aroclor 1254-induced differential protein expression. Two proteins were found to be differentially expressed in the cerebellum following PCB exposure while 18 proteins were differentially expressed in the hippocampus. These proteins are related to energy metabolism in mitochondria (ATP synthase, sub unit {beta} (ATP5B), creatine kinase, and malate dehydrogenase), calcium signaling (voltage-dependent anion-selective channel protein 1 (VDAC1) and ryanodine receptor type II (RyR2)), and growth of the nervous system (dihydropyrimidinase-related protein 4 (DPYSL4), valosin-containing protein (VCP)). Results suggest that Aroclor 1254-like persistent chemicals may alter energy metabolism and intracellular signaling, which might result in developmental neurotoxicity. -- Highlights: Black-Right-Pointing-Pointer We performed brain proteomic analysis of rats exposed to the neurotoxicant

  3. CATALYTIC STEAM REFORMING OF CHLOROCARBONS: POLYCHLORINATED BIPHENYLS (PCBS). (R826694C633)

    Science.gov (United States)

    Experiments with commercial askarals (Aroclors 1221, 1248 and 1254) have confirmed the feasibility of catalytic steam reforming as a method for destroying polychlorinated biphenyls (PCBs). Rhodium, platinum and nickel supported on Effects of a mixture of non-ortho- and mono-ortho-polychlorinated biphenyls on reproduction in Fundulus heteroclitus (Linnaeus)

    Energy Technology Data Exchange (ETDEWEB)

    Black, D.E.; Gutjahr-Gobell, R.; Pruell, R.J.; Bergen, B. [Environmental Protection Agency, Narragansett, RI (United States); McElroy, A.E. [State Univ. of New York, Stony Brook, NY (United States). Marine Sciences Research Center

    1998-07-01

    To assess the effects of polychlorinated biphenyls (PCBs) on reproduction, female Fundulus heteroclitus were exposed to a mixture of non-ortho- and mono-ortho-PCBs, mimicking the mixture found in fish collected from New Bedford Harbor, Massachusetts, USA, a PCB-contaminated estuary. Exposure was by intraperitoneal injection of the mixture dissolved in corn oil. Doses of 0.76, 3.8, and 19 {micro}g PCB mixture per gram of wet weight produced liver concentrations of 2.99, 12.2, and 32.8 {micro}g non-ortho- and mono-ortho-PCBs per gram of dry liver, with dioxin toxic equivalency concentrations (TEQs) of 0.0963, 0.409, and 0.720 ng/g, respectively. Female mortality was 58%, and egg production was reduced by 77% at the highest dose, compared to controls. Food consumption declined with increasing PCB concentration, suggesting that PCBs act indirectly to reduce fecundity through an energetic effect. Pituitary gonadotropin content appeared to be suppressed at the highest dose, but the ability of ovarian follicles to produce estradiol and testosterone in vitro was not impaired. Significant residue-effects linkages were found, with TEQ emerging as a potential indicator of adverse effects. Mortality was directly related, and egg production was inversely related to log{sub 10}TEQ. Multiple regression analysis indicated that egg production was directly related to pituitary gonadotropin content and food consumption.

  4. Aroclor 1248 exposure leads to immunomodulation, decreased disease resistance and endocrine disruption in the brown bullhead, Ameiurus nebulosus

    Science.gov (United States)

    Iwanowicz, L.R.; Blazer, V.S.; McCormick, S.D.; Van Veld, P.A.; Ottinger, C.A.

    2009-01-01

    The brown bullhead Ameiurus nebulosus is a species of the family Ictaluridae commonly used as a sentinel of environmental contamination. While these fish have been utilized for this purpose in areas contaminated with polychlorinated biphenyls (PCBs), few controlled, laboratory-based studies have been designed to document the effects of PCB mixtures in this species. Here, brown bullhead were exposed to the PCB mixture, Aroclor 1248, via intraperitoneal injection and the effects on immune function, plasma hormones and disease resistance were evaluated. Exposure to this mixture led to a decrease in bactericidal activity and circulating antibodies to Edwardsiella ictaluri present from a previous exposure to this pathogen. A subsequent E. ictaluri disease challenge led to significantly higher mortality in A1248 treated fish compared to vehicle-control fish. The mitogenic response to the T-cell mitogen, phytohemaglutinin-P, was increased compared to vehicle-control fish. The steroid hormone, cortisol, and the thyroid hormone, T3, were also significantly lower in A1248 exposed fish. In summary, we have validated a number of functional immune assays for application in brown bullhead immunotoxicity studies. Additionally, we have demonstrated that the PCB mixture (A1248) modulates both immune function and endocrine physiology in brown bullhead. Such data may compliment the interpretation of data yielded from applied field studies conducted in PCB contaminated aquatic ecosystems.

  5. Aroclor 1248 exposure leads to immunomodulation, decreased disease resistance and endocrine disruption in the brown bullhead, Ameiurus nebulosus.

    Science.gov (United States)

    Iwanowicz, Luke R; Blazer, Vicki S; McCormick, Stephen D; Vanveld, Peter A; Ottinger, Christopher A

    2009-06-04

    The brown bullhead Ameiurus nebulosus is a species of the family Ictaluridae commonly used as a sentinel of environmental contamination. While these fish have been utilized for this purpose in areas contaminated with polychlorinated biphenyls (PCBs), few controlled, laboratory-based studies have been designed to document the effects of PCB mixtures in this species. Here, brown bullhead were exposed to the PCB mixture, Aroclor 1248, via intraperitoneal injection and the effects on immune function, plasma hormones and disease resistance were evaluated. Exposure to this mixture led to a decrease in bactericidal activity and circulating antibodies to Edwardsiella ictaluri present from a previous exposure to this pathogen. A subsequent E. ictaluri disease challenge led to significantly higher mortality in A1248 treated fish compared to vehicle-control fish. The mitogenic response to the T-cell mitogen, phytohemaglutinin-P, was increased compared to vehicle-control fish. The steroid hormone, cortisol, and the thyroid hormone, T3, were also significantly lower in A1248 exposed fish. In summary, we have validated a number of functional immune assays for application in brown bullhead immunotoxicity studies. Additionally, we have demonstrated that the PCB mixture (A1248) modulates both immune function and endocrine physiology in brown bullhead. Such data may compliment the interpretation of data yielded from applied field studies conducted in PCB contaminated aquatic ecosystems.

  6. Augmented atherogenesis in ApoE-null mice co-exposed to polychlorinated biphenyls and 2,3,7,8-tetrachlorodibenzo-p-dioxin

    International Nuclear Information System (INIS)

    Shan, Qiuli; Wang, Jing; Huang, Fengchen; Lv, Xiaowen; Ma, Min; Du, Yuguo

    2014-01-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) and polychlorinated biphenyls (PCBs) are persistent organic pollutants found as complex mixtures in the environment throughout the world. Therefore, humans are ubiquitously and simultaneously exposed to TCDD and PCBs. TCDD and PCBs alone have been linked to atherosclerosis. However, the effects of interactions or synergism between TCDD and PCBs on atherogenesis are unknown. We investigated the possible enhanced atherogenesis by co-exposure to TCDD and PCBs and the potential mechanism(s) involved in this enhancement. Male ApoE −/− mice were exposed to TCDD (15 μg/kg) and Aroclor1254 (55 mg/kg, a representative mixture of PCBs) alone or in combination by intraperitoneal injection four times over six weeks of duration. Our results showed that mice exposed to TCDD alone, but not Aroclor1254 alone, developed atherosclerotic lesions. Moreover, we found that atherosclerotic disease was exacerbated to the greatest extent in mice co-exposed to TCDD and Aroclor1254. The enhanced lesions correlated with several pro-atherogenic changes, including a marked increase in the accumulation of the platelet-derived chemokine PF4, and the expression of the proinflammatory cytokine MCP-1 and the critical immunity gene-RIG-I. Our data demonstrated that co-exposure to TCDD and Aroclor1254 markedly enhanced atherogenesis in ApoE −/− mice. Significantly, our observations suggest that combined exposure to TCDD and PCBs may be a greater cardiovascular health risk than previously anticipated from individual studies. - Highlights: • Augmented atherogenesis was found in ApoE −/− mice co-exposed to Aroclor1254 and TCDD. • Enhanced expression of PF4, MCP-1 and RIG-I correlated with augmented lesions. • POPs combination may be a greater cardiovascular health risk than individual POPs

  7. Augmented atherogenesis in ApoE-null mice co-exposed to polychlorinated biphenyls and 2,3,7,8-tetrachlorodibenzo-p-dioxin

    Energy Technology Data Exchange (ETDEWEB)

    Shan, Qiuli [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Wang, Jing, E-mail: avaecn@gmail.com [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Huang, Fengchen [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Lv, Xiaowen [Feed Safety Reference Laboratory of Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Zhongguancun South Street 12, Beijing 100081 (China); Ma, Min [Laboratory of Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Du, Yuguo [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China)

    2014-04-15

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) and polychlorinated biphenyls (PCBs) are persistent organic pollutants found as complex mixtures in the environment throughout the world. Therefore, humans are ubiquitously and simultaneously exposed to TCDD and PCBs. TCDD and PCBs alone have been linked to atherosclerosis. However, the effects of interactions or synergism between TCDD and PCBs on atherogenesis are unknown. We investigated the possible enhanced atherogenesis by co-exposure to TCDD and PCBs and the potential mechanism(s) involved in this enhancement. Male ApoE{sup −/−} mice were exposed to TCDD (15 μg/kg) and Aroclor1254 (55 mg/kg, a representative mixture of PCBs) alone or in combination by intraperitoneal injection four times over six weeks of duration. Our results showed that mice exposed to TCDD alone, but not Aroclor1254 alone, developed atherosclerotic lesions. Moreover, we found that atherosclerotic disease was exacerbated to the greatest extent in mice co-exposed to TCDD and Aroclor1254. The enhanced lesions correlated with several pro-atherogenic changes, including a marked increase in the accumulation of the platelet-derived chemokine PF4, and the expression of the proinflammatory cytokine MCP-1 and the critical immunity gene-RIG-I. Our data demonstrated that co-exposure to TCDD and Aroclor1254 markedly enhanced atherogenesis in ApoE{sup −/−} mice. Significantly, our observations suggest that combined exposure to TCDD and PCBs may be a greater cardiovascular health risk than previously anticipated from individual studies. - Highlights: • Augmented atherogenesis was found in ApoE{sup −/−} mice co-exposed to Aroclor1254 and TCDD. • Enhanced expression of PF4, MCP-1 and RIG-I correlated with augmented lesions. • POPs combination may be a greater cardiovascular health risk than individual POPs.

  8. External heart deformities in passerine birds exposed to environmental mixtures of polychlorinated biphenyls during development.

    Science.gov (United States)

    DeWitt, Jamie C; Millsap, Deborah S; Yeager, Ronnie L; Heise, Steve S; Sparks, Daniel W; Henshel, Diane S

    2006-02-01

    Necropsy-observable cardiac deformities were evaluated from 283 nestling passerines collected from one reference site and five polychlorinated biphenyl (PCB)-contaminated sites around Bloomington and Bedford, Indiana, USA. Hearts were weighed and assessed on relative scales in three dimensions (height, length, and width) and for externally visible deformities. Heart weights normalized to body weight (heart somatic index) were decreased significantly at the more contaminated sites in both house wren (Troglodytes aedon) and tree swallow (Tachycineta bicolor). Heart somatic indices significantly correlated with log PCB concentrations in Carolina chickadee (Parus carolinesis) and tree swallow and with log 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalent values in tree swallow alone. Ventricular length was increased significantly in eastern bluebirds (Sialia sialis) and decreased significantly in Carolina chickadee and tree swallow from contaminated sites versus the reference site. Heart length regressed significantly against the log PCB concentrations (Carolina chickadee and tree swallow) or the square of the PCB concentrations (red-winged blackbird [Agelaius phoeniceus]) in a sibling bird. The deformities that were observed most at the contaminated sites included abnormal tips (pointed, rounded, or flattened), center rolls, macro- and microsurface roughness, ventricular indentations on the ventral or dorsal surface, lateral ventricular notches, visibly thin ventricular walls, and changes in overall heart shape. A pooled heart deformity index regressed significantly against the logged contaminant concentrations for all species except red-winged blackbird. These results indicate that developmental changes in heart morphometrics and shape abnormalities are quantifiable and may be sensitive and useful indicators of PCB-related developmental impacts across many avian species.

  9. Bioaugmentation of a historically contaminated soil by polychlorinated biphenyls with Lentinus tigrinus

    Directory of Open Access Journals (Sweden)

    Federici Ermanno

    2012-03-01

    Full Text Available Abstract Background Several species belonging to the ecological group of white-rot basidiomycetes are able to bring about the remediation of matrices contaminated by a large variety of anthropic organic pollutants. Among them, polychlorobiphenyls (PCBs are characterized by a high recalcitrance due to both their low bioavailability and the inability of natural microbial communities to degrade them at significant rates and extents. Objective of this study was to assess the impact of a maize stalk-immobilized Lentinus tigrinus CBS 577.79 inoculant combined with soybean oil (SO, as a possible PCB-mobilizing agent, on the bioremediation and resident microbiota of an actual Aroclor 1260 historically contaminated soil under unsaturated solid-phase conditions. Results Best overall PCB depletions (33.6 ± 0.3% and dechlorination (23.2 ± 1.3% were found after 60 d incubation in the absence of SO where, however, the fungus appeared to exert adverse effects on both the growth of biphenyl- and chlorobenzoate-degrading bacteria and the abundance of genes coding for both biphenyl dioxygenase (bph and catechol-2,3-dioxygenase. A significant (P bph. Conclusions The PCB depletion extents obtained in the presence of L. tigrinus are by far higher than those reported in other remediation studies conducted under unsaturated solid phase conditions on actual site soils historically contaminated by Aroclor 1260. These results suggest that the bioaugmentation strategy with the maize stalk-immobilized mycelium of this species might be promising in the reclamation of PCB-contaminated soils. The addition of SO to matrices contaminated by technical PCB mixtures, such as Aroclor 1242 and Delor 103 and characterized by a large preponderance of low chlorinated congeners, might not be advisable.

  10. The occurrence and significance of polychlorinated biphenyls in the environment

    Science.gov (United States)

    Dustman, E.H.; Stickel, L.F.; Blus, L.J.; Reichel, W.L.; Wiemeyer, Stanley N.

    1971-01-01

    SUMMARY: Polychlorinated biphenyls constitute a group of chlorine-bearing compounds of industrial origin that have permeated the natural environment throughout the world. Their chemical structure resembles that of some of the organochlorine pesticides. They are troublesome interferences in gas chromatographic analysis of these pesticides. Although methods have been developed to overcome analytical problems, measurements of quantity still are only approximate. Special studies in the United States, Netherlands, and Great Britain have traced PCB's to industrial effluent, but other possible sources have not been followed. Their use in paints, cartons, and insulating fluids suggests that environmental pollution may be from many different sources. PCB's are present in fish and wildlife in many countries of the world. Quantities are higher in animals living near industrial areas. PCB's build up in biological food chains with increases of tens to thousands of times from lower to higher organisms. Experimental studies have shown that PCB's have a toxicity to mallards, pheasants, bobwhite quail, coturnix quail, red-winged blackbirds, starlings, cowbirds, and grackles that is of the same order as the toxicity of DDE to these species. Overt signs of poisoning also are similar to those caused by compounds of the DDT group. Toxic effects of DDE and Aroclor 1254 to coturnix chicks were additive, but not synergistic. PCB's containing higher percentages of chlorine are more toxic to birds than those containing lower percentages. PCB's of foreign manufacture contained contaminants to an extent that greatly increased their toxicity Aroclor 1242. Statistical evaluations of the role that different chemicals may play in thinning of eggshells of brown pelicans show that DDE residues correlate better with shell thinning than do residues of dieldrin or PCB's. Studies of the effects of PCB's in the environment are as yet insufficient for well-rounded conclusions. The evidence available

  11. Health and productivity of dairy cows fed polychlorinated biphenyls

    Energy Technology Data Exchange (ETDEWEB)

    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.

  12. Analytical method of polychlorinated biphenyls(PCBs) in transformer oil

    Energy Technology Data Exchange (ETDEWEB)

    Shin, S.K. [National Institute of Environmental Research, Incheon (Korea); Kim, H.J.; Chung, D.; Kim, K.S.; Kim, J.K.; Chung, Y.H.; Chung, I.R.

    2004-09-15

    Polychlorinated biphenyls (PCBs) is a chlorinated biphenyl compound with the general formula C{sub 12}H{sub 10-n}/Cl{sub n}. PCBs generally occur as mixtures, where n can vary from 1 to 10. The 10 sites available for possible chlorine substitution result in 209 possible PCB congeners. There is now considerable concern regarding; the presence of PCB congeners in insulating oils used within large-scale electrical supply systems. Due to its outstanding chemical and thermal stabilities and electrical insulation properties, the commercial and industrial products of polychlorinated biphenyls (PCBs), such as Aroclors, Kaneclors, Clophens, Phenaclors etc., had been widely used as thermal oil and transformer oil from 1930s until the 1970s. PCBs from a group of persistent organic pollutants of the environment, especially dangerous to living organisms due to high toxicity, persistency, and bio-concentration in adipose tissue. Despite of this fact, PCB-contaminated oils are still commonly encountered partly because PCBs used as dielectric liquids in transformer and condenser. The source of PCBs in environments can range from used transformer oils or dielectric liquids to liquid wastes, and some PCBs contamination is occurred due to the re-use of incompletely reconditioned oil. The current action plan of Republic of Korea dictates that organizations with electrical equipment contaminated with more than 2 mg/L PCBs will need to treat as PCBs-containing wastes, and 50mg/L of PCBs or PCBs equivalent to be treated as a pure PCB preparation. In this study, transformer oils analyzed based on guideline for PCBs analytical method of transformer oil in Korea.

  13. Analysis the mixtures of polyphenyls by gas chromatrogaphie. 1.- Area response for biphenyl and terphenyls relative to triphenylmethane; Analisis de polifenilos por cromatografia de gases 1.- Respuesta relativa del bifenilo y terfenilos respecto al trifenilmetano

    Energy Technology Data Exchange (ETDEWEB)

    Perez Garcia, M

    1966-07-01

    The relative performances of the thermal conductivity and flame ionization detectors towards triphenylmethane were investigated for each one of the components of biphenyl of biphenyl and terphenyl mixtures. The influence of the concentration of the considered compound as well as the influence derived from the present of all other components on the above-mentioned relative performance were studied. A 2 m long column filled with 50-70 mesh stomacher containing 20% apiezon L was used to carry out the study with the thermal conductivity detector by keeping the column at 300 degree centigree using helium gas as carrier. (Author) 13 refs.

  14. Concentrations of polychlorinated biphenyls in soil and indoor dust associated with electricity generation facilities in Lagos, Nigeria.

    Science.gov (United States)

    Folarin, Bilikis Temitope; Abdallah, Mohamed Abou-Elwafa; Oluseyi, Temilola; Olayinka, Kehinde; Harrad, Stuart

    2018-09-01

    Concentrations of 7 indicator polychlorinated biphenyls (PCBs) were measured in dust and soil samples from 12 power stations collected over the two major seasons of the Nigerian climate. Median ƩPCB 7 concentrations in soil ranged from 2 ng/g for power station A to 220 ng/g for power station I; while those in dust ranged from 21 ng/g for power station L to 2200 ng/g for power station I. For individual congeners, median PCB concentrations ranged from 3.8 ng/g for PCB 101 to 52 ng/g for PCB 180 in dust, and  transmission > distribution). Congener patterns in dust and soil samples were compared using principal component analysis (PCA) with those in transformer oil samples from 3 of the power stations studied and with common PCB mixtures (Aroclors). This revealed congener patterns in soil were more closely related to that in the transformer oil than dust. Congener patterns in most samples were similar to Aroclor 1260. Concentrations of PCBs in soil samples close to the transformers significantly exceeded those in soil sampled further away. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. Phylogenetically distinct bacteria involve extensive dechlorination of aroclor 1260 in sediment-free cultures.

    Directory of Open Access Journals (Sweden)

    Shanquan Wang

    Full Text Available Microbial reductive dechlorination of the persistent polychlorinated biphenyls (PCBs is attracting much attention in cleanup of the contaminated environment. Nevertheless, most PCB dechlorinating cultures require presence of sediment or sediment substitutes to maintain their dechlorination activities which hinders subsequent bacterial enrichment and isolation processes. The information on enriching sediment-free PCB dechlorinating cultures is still limited. In this study, 18 microcosms established with soils and sediments were screened for their dechlorination activities on a PCB mixture - Aroclor 1260. After one year of incubation, 10 out of 18 microcosms showed significant PCB dechlorination with distinct dechlorination patterns (e.g., Process H, N and T classified based on profiles of PCB congeners loss and new congeners formation. Through serial transfers in defined medium, six sediment-free PCB dechlorinating cultures (i.e., CW-4, CG-1, CG-3, CG-4, CG-5 and SG-1 were obtained without amending any sediment or sediment-substitutes. PCB dechlorination Process H was the most frequently observed dechlorination pattern, which was found in four sediment-free cultures (CW-4, CG-3, CG-4 and SG-1. Sediment-free culture CG-5 showed the most extensive PCB dechlorination among the six cultures, which was mediated by Process N, resulting in the accumulation of penta- (e.g., 236-24-CB and tetra-chlorobiphenyls (tetra-CBs (e.g., 24-24-CB, 24-25-CB, 24-26-CB and 25-26-CB via dechlorinating 30.44% hepta-CBs and 59.12% hexa-CBs after three months of incubation. For culture CG-1, dechlorinators mainly attacked double flanked meta-chlorines and partially ortho-chlorines, which might represent a novel dechlorination pattern. Phylogenetic analysis showed distinct affiliation of PCB dechlorinators in the microcosms, including Dehalogenimonas and Dehalococcoides species. This study broadens our knowledge in microbial reductive dechlorination of PCBs, and provides

  16. The inhibition of LPS-induced splenocyte proliferation by ortho-substituted and microbially dechlorinated polychlorinated biphenyls is associated with a decreased expression of cyclin D2

    International Nuclear Information System (INIS)

    Smithwick, L. Ashley; Quensen, John F.; Smith, Andrew; Kurtz, David T.; London, Lucille; Morris, Pamela J.

    2004-01-01

    Immunological effects of polychlorinated biphenyls (PCBs) have been demonstrated in our laboratories with the preferential inhibition of lipopolysaccharide (LPS)-induced splenocyte proliferation by ortho-substituted PCB congeners. An investigation of the mechanism behind this immunotoxicity revealed an interruption in the progression of murine lymphocytes from G 0 /G 1 into S phase by Aroclor 1242 and the di-ortho-substituted congener, 2,2'-chlorobiphenyl (CB), whereas, a non-ortho-substituted congener, 4,4'-CB, did not affect cell cycle progression. This interruption of cell cycle progression by 2,2'-CB and Aroclor 1242 was associated with a decreased expression of the cell cycle regulatory protein, cyclin D2, while expression was not affected by exposure to the non-ortho-substituted 4,4'-CB. These results suggest the preferential inhibition of LPS-induced splenocyte proliferation by ortho-substituted congeners is a result of a decreased expression of cyclin D2, which leads to an interruption in cell cycle progression. In addition, PCB mixtures with an increased percentage of chlorines in the ortho position following an environmentally occurring degradation process inhibited LPS-induced proliferation, interrupted cell cycle progression, and decreased cyclin D2 expression. This study provides evidence for a mechanism of action of the immunological effects of ortho-substituted individual congeners as well as environmentally relevant mixtures enriched in congeners with this substitution pattern

  17. Inhibition of LPS-induced splenocyte proliferation by ortho-substituted polychlorinated biphenyl congeners

    International Nuclear Information System (INIS)

    Smithwick, L. Ashley; Smith, Andrew; Quensen, John F.; Stack, Allison; London, Lucille; Morris, Pamela J.

    2003-01-01

    Polychlorinated biphenyls (PCBs) are persistent environmental contaminants, and their ubiquitous nature has prompted studies of their potential health hazards. As a result of their lipophilic nature, PCBs accumulate in breast milk and subsequently affect the health of offspring of exposed individuals. Biological effects of PCBs in animals have mostly been attributed to coplanar congeners, although effects of ortho congeners also have been demonstrated. To investigate the relationship of immunotoxicity and chlorine substitution pattern, the effects of PCB congeners and mixtures of ortho and non-ortho-substituted constituents of Aroclor 1242 on splenocytes from C57B1/6 mice were examined. The immunotoxic endpoints investigated included splenocyte viability, lipopolysaccharide (LPS)-induced splenocyte proliferation, and LPS-induced antibody secretion. Congeners with multiple ortho chlorines preferentially inhibited splenocyte proliferation as compared with non- or mono-ortho-substituted congeners. However, mixtures of non- and mono-ortho-substituted congeners and multi-ortho-substituted congeners inhibited LPS-induced splenocyte proliferation and antibody secretion at similar concentrations. Exposure of splenocytes to these mixtures did not activate the aryl hydrocarbon receptor (AhR) signal transduction pathway. These results suggest individual multi-ortho-substituted congeners preferentially inhibit LPS-induced splenocyte proliferation, while congeners not exhibiting an effect individually may have additive effects in a mixture to produce an immunotoxic response through an AhR-independent pathway

  18. Polychlorinated biphenyls and their interaction with the environment

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Directory of Open Access Journals (Sweden)

    Ayman Mohamed Megahed

    2015-01-01

    Full Text Available 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.

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

    Science.gov (United States)

    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.

  2. Activated carbon immobilizes residual polychlorinated biphenyls in weathered contaminated soil.

    Science.gov (United States)

    Langlois, Valérie S; Rutter, Allison; Zeeb, Barbara A

    2011-01-01

    Activated carbon (AC) has recently been shown to be effective in sequestering persistent organic pollutants (POPs) from aquatic sediments. Most studies have demonstrated significant reductions of POP concentrations in water and in aquatic organisms; however, limited data exist on the possibility of using AC to immobilize remaining POPs at terrestrial contaminated sites. Under greenhouse conditions, pumpkin ssp cv. Howden) were grown, and red wiggler worms () were exposed to an industrial contaminated soil containing a mixture of polychlorinated biphenyls (PCBs), i.e., Aroclors 1254 and 1260) treated with one of four concentrations of AC (0.2, 0.8, 3.1, and 12.5%) for 2 mo. The addition of AC to contaminated soils virtually eliminated the bioavailability of PCBs to the plant and invertebrate species. There were reductions in PCB concentrations of more than 67% in ssp and 95% in . These data suggest that AC could be included as part of comprehensive site closure strategy at PCB-contaminated sites. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  3. Bacterial degradation of Aroclor 1242 in the mycorrhizosphere soils of zucchini (Cucurbita pepo L.) inoculated with arbuscular mycorrhizal fungi.

    Science.gov (United States)

    Qin, Hua; Brookes, Philip C; Xu, Jianming; Feng, Youzhi

    2014-11-01

    A greenhouse experiment was conducted to investigate the effects of zucchini (Cucurbita pepo L.), inoculated with the arbuscular mycorrhizal (AM) species Acaulospora laevis, Glomus caledonium, and Glomus mosseae, on the soil bacterial community responsible for Aroclor 1242 dissipation. The dissipation rates of Aroclor 1242 and soil bacteria abundance were much higher with the A. laevis and G. mosseae treatments compared to the non-mycorrhizal control. The biphenyl dioxygenase (bphA) and Rhodococcus-like 2,3-dihydroxybiphenyl dioxygenase (bphC) genes were more abundant in AM inoculated soils, suggesting that the bphA and Rhodococcus-like bphC pathways play an important role in Aroclor 1242 dissipation in the mycorrhizosphere. The soil bacterial communities were dominated by classes Betaproteobacteria and Actinobacteria, while the relative proportion of Actinobacteria was significantly (F=2.288, P<0.05) correlated with the PCB congener profile in bulk soil. Our results showed that AM fungi could enhance PCB dissipation by stimulating bph gene abundance and the growth of specific bacterial groups.

  4. Effects of DDE and PCB (Aroclor 1260) on experimentally poisoned little brown bats (Myotis lucifugus): Lethal brain concentrations

    Science.gov (United States)

    Clark, D.R.; Stafford, C.J.

    1981-01-01

    Adult female little brown bats (Myotis lucifugus) were collected in a church attic in North East, Cecil County, Md. Mealworms (Tenebrio molitor) containing organochlorine pollutants were fed to the bats as follows: 5 bats were dosed at 480 ppm DDE, 12 at 150 ppm DDE, 5 at 1000 ppm polychlorinated biphenyl (PCB; Aroclor 1260), and 12 at 15 ppm PCB. Seven other bats were fed untreated mealworms. The objective was to elevate brain levels of DDE and PCB to lethality and measure these concentrations. During 40 d of dosage, one DDE-dosed bat and two PCB-dosed bats died after exhibiting the prolonged tremor that characterizes organochlorine poisoning. After dosage, surviving bats were starved to elevate brain levels of toxicants, and three additional DDE-dosed bats had tremors before dying. The mean brain concentration of DDE diagnostic of death was estimated as 603 ppm, range 540-670 ppm. This mean is 16-18% higher than means for Mexican free-tailed bats (Tadarida brasiliensis) and common grackles (Quiscalus quiscula), and may indicate less sensitivity. Lethal brain concentrations of Aroclor 1260 were 1300 and 1500 ppm. Such values appear to be higher than values (Aroclor 1254) for brown-headed cowbirds (Molothrus ater). During starvation, DDE-dosed bats lost weight about 24% faster than controls. If smaller amounts of stored DDE cause increases in metabolic rates of nonfeeding bats, as during hibernation or migration, the result could be premature energy depletion and increased mortality.

  5. Selective separation of hydroxy polychlorinated biphenyls (HO-PCBs) by the structural recognition on the molecularly imprinted polymers: Direct separation of the thyroid hormone active analogues from mixtures

    International Nuclear Information System (INIS)

    Kubo, Takuya; Matsumoto, Hideyuki; Shiraishi, Fujio; Nomachi, Makoto; Nemoto, Koji; Hosoya, Ken; Kaya, Kunimitsu

    2007-01-01

    We developed novel separation media for hydroxy polychlorinated biphenyls (HO-PCBs) using the molecular imprinting techniques. The results of evaluation for the molecularly imprinted polymers (MIPs) by the liquid chromatography (LC) suggested that MIPs had selective separation ability for certain HO-PCB analogues. The results of the LC evaluations and molecular modeling indicated that the molecular volumes and pK a values of template molecules were related with the retention factor of HO-PCBs. Additionally, according to the detail evaluation toward the selective separation behaviors of MIPs, these HO-PCB analogues have low pK a values dependent on their chemical structures. In other words, the prepared MIPs had selective recognition ability against the analogues, which have an OH group on a phenyl carbon and two chlorine atoms on the both neighboring carbons of the carbon attached with the OH group. Moreover, these analogues may have a potential for thyroid hormone activities so that we attempted to separate these analogues directly from mixtures of HO-PCBs using a prepared MIP

  6. Gene expression profiles in the cerebellum and hippocampus following exposure to a neurotoxicant, Aroclor 1254: Developmental effects.

    Science.gov (United States)

    The developmental consequences of exposure to the polychlorinated biphenyls (PCBs) have been widely studied, making PCBs a unique model to understand issues related to environmental mixture of persistent chemicals. PCB exposure in humans adversely affects neurocognitive developm...

  7. Nanoscale zerovalent iron alters soil bacterial community structure and inhibits chloroaromatic biodegradation potential in Aroclor 1242-contaminated soil

    International Nuclear Information System (INIS)

    Tilston, Emma L.; Collins, Chris D.; Mitchell, Geoffrey R.; Princivalle, Jessica; Shaw, Liz J.

    2013-01-01

    Nanoscale zerovalent iron (nZVI) has potential for the remediation of organochlorine-contaminated environments. Environmental safety concerns associated with in situ deployment of nZVI include potential negative impacts on indigenous microbes whose biodegradative functions could contribute to contaminant remediation. With respect to a two-step polychlorinated biphenyl remediation scenario comprising nZVI dechlorination followed by aerobic biodegradation, we examined the effect of polyacrylic acid (PAA)-coated nZVI (mean diameter = 12.5 nm) applied at 10 g nZVI kg −1 to Aroclor-1242 contaminated and uncontaminated soil over 28 days. nZVI had a limited effect on Aroclor congener profiles, but, either directly or indirectly via changes to soil physico-chemical conditions (pH, Eh), nZVI addition caused perturbation to soil bacterial community composition, and reduced the activity of chloroaromatic mineralizing microorganisms. We conclude that nZVI addition has the potential to inhibit microbial functions that could be important for PCB remediation strategies combining nZVI treatment and biodegradation. Highlights: ► Impact of nano-sized zerovalent iron on microbes was investigated in soil microcosms. ► Zerovalent iron had short-lived effects on redox potential and Aroclor dechlorination. ► Microbial populations also showed short-lived perturbations in their size. ► The activity of chloroaromatic degrading microbes did not recover within 28 days. ► Zerovalent iron application inhibits ensuing PCB bioremediative microbial functions. - nZVI inhibits microbial functions of potential importance for remediation strategies combining nZVI treatment and biodegradation.

  8. Polychlorinated Biphenyls Induce Mitochondrial Dysfunction in SH-SY5Y Neuroblastoma Cells.

    Directory of Open Access Journals (Sweden)

    Stefania Cocco

    Full Text Available Chronic exposure to polychlorinated biphenyls (PCBs, ubiquitous environmental contaminants, can adversely affect the development and function of the nervous system. Here we evaluated the effect of PCB exposure on mitochondrial function using the PCB mixture Aroclor-1254 (A1254 in SH-SY5Y neuroblastoma cells. A 6-hour exposure to A1254 (5 μg/ml reduced cellular ATP production by 45%±7, and mitochondrial membrane potential, detected by TMRE, by 49%±7. Consistently, A1254 significantly decreased oxidative phosphorylation and aerobic glycolysis measured by extracellular flux analyzer. Furthermore, the activity of mitochondrial protein complexes I, II, and IV, but not V (ATPase, measured by BN-PAGE technique, was significantly reduced after 6-hour exposure to A1254. The addition of pyruvic acid during exposure to A1254 significantly prevent A1254-induced cell injury, restoring resting mitochondrial membrane potential, ATP levels, oxidative phosphorylation and aerobic glycolysis. Furthermore, pyruvic acid significantly preserved the activity of mitochondrial complexes I, II and IV and increased basal activity of complex V. Collectively, the present results indicate that the neurotoxicity of A1254 depends on the impairment of oxidative phosphorylation, aerobic glycolysis, and mitochondrial complexes I, II, and IV activity and it was counteracted by pyruvic acid.

  9. Polychlorinated biphenyl congener patterns in tree swallows (Tachycineta bicolor) nesting in the Housatonic River watershed, western Massachusetts, USA, using a novel statistical approach

    International Nuclear Information System (INIS)

    Custer, Christine M.; Read, Lorraine B.

    2006-01-01

    A novel application of a commonly used statistical approach was used to examine differences in polychlorinated biphenyl (PCB) congener patterns among locations and sample matrices in tree swallows (Tachycineta bicolor) nesting in the Housatonic River watershed in western Massachusetts, USA. The most prevalent PCB congeners in tree swallow tissue samples from the Housatonic River watershed were Ballsmitter Zell numbers 153, 138, 180, 187, 149, 101, and 170. These congeners were seven of the eight most prevalent congeners in Aroclor[reg] 1260, the PCB mixture that was the primary source of contamination in the Housatonic River system. Using paired-Euclidean distances and tolerance limits, it was demonstrated that congener patterns in swallow tissues from sites on the main stem of the Housatonic River were more similar to one another than to two sites upstream of the contamination or from a nearby reference area. The congener patterns also differed between the reference area and the two upstream tributaries and between the two tributaries. These pattern differences were the same in both pipper (eggs or just hatched nestlings) and 12-day-old nestling samples. Lower-chlorinated congeners appeared to be metabolized in nestlings and pippers compared to diet, and metabolized more in pippers compared to nestlings. Euclidean distances and tolerance limits provide a simple and statistically valid method to compare PCB congener patterns among groups. - Polychlorinated biphenyl congener patterns in swallows differed between the main stem of the Housatonic River, MA and other locations in the watershed

  10. Blarina brevicauda as a biological monitor of polychlorinated biphenyls: evaluation of hepatic cytochrome P450 induction.

    Science.gov (United States)

    Russell, Julie S; Halbrook, Richard S; Woolf, Alan; French, John B; Melancon, Mark J

    2004-08-01

    We assessed the value of short-tailed shrews (Blarina brevicauda) as a possible biomonitor for polychlorinated biphenyl pollution through measurement of the induction of hepatic cytochrome P450 and associated enzyme activities. First, we checked the inducibility of four monooxygenases (benzyloxyresorufin-O-dealkylase [BROD], ethoxyresorufin-O-dealkylase [EROD], methoxyresorufin-O-dealkylase [MROD], and pentoxyresorufin-O-dealkylase [PROD]) by measuring the activity of these enzymes in hepatic microsomes prepared from shrews injected with beta-naphthoflavone (betaNF) or phenobarbital (PB), typical inducers of cytochrome P4501A (CYP1A) and CYP2B enzyme families, respectively. Enzyme activity was induced in shrews that received betaNF but not in shrews that received PB; PROD was not induced by either exposure. Later, shrews were exposed to a mixture of polychlorinated biphenyls (PCBs) (Aroclor 1242:1254, in 1:2 ratio) at 0.6, 9.6, and 150 ppm in food, for 31 d. Induction in these shrews was measured by specific enzyme activity (BROD, EROD, and MROD) in hepatic microsomes, by western blotting of solubilized microsomes against antibodies to CYP1A or CYP2B, and by duration of sodium pentobarbital-induced sleep. These three CYP enzymes were induced in shrews by PCBs at similar levels of exposure as in cotton rat (Sigmodon hispidus). Neither sleep time nor the amount of CYP2B family protein were affected by PCB exposure. Blarina brevicauda can be a useful biomonitor of PCBs that induce CYP1A, especially in habitats where they are the abundant small mammal.

  11. Mixture

    Directory of Open Access Journals (Sweden)

    Silva-Aguilar Martín

    2011-01-01

    Full Text Available Metals are ubiquitous pollutants present as mixtures. In particular, mixture of arsenic-cadmium-lead is among the leading toxic agents detected in the environment. These metals have carcinogenic and cell-transforming potential. In this study, we used a two step cell transformation model, to determine the role of oxidative stress in transformation induced by a mixture of arsenic-cadmium-lead. Oxidative damage and antioxidant response were determined. Metal mixture treatment induces the increase of damage markers and the antioxidant response. Loss of cell viability and increased transforming potential were observed during the promotion phase. This finding correlated significantly with generation of reactive oxygen species. Cotreatment with N-acetyl-cysteine induces effect on the transforming capacity; while a diminution was found in initiation, in promotion phase a total block of the transforming capacity was observed. Our results suggest that oxidative stress generated by metal mixture plays an important role only in promotion phase promoting transforming capacity.

  12. Developmental and neurobehavioral effects of perinatal exposure to polychlorinated biphenyls in mice.

    Science.gov (United States)

    Sugawara, Norio; Nakai, Kunihiko; Nakamura, Tomoyuki; Ohba, Takashi; Suzuki, Keita; Kameo, Satomi; Satoh, Chieko; Satoh, Hiroshi

    2006-05-01

    Because behavioral deficits associated with gestational exposure to polychlorinated biphenyls (PCBs) have been a concern, we studied the developmental and neurobehavioral effects of perinatal exposure to Aroclor 1254 (A1254), a commercial mixture of PCBs, in mice. The PCB mixture (A1254; 0, 6, 18, and 54 mg/kg body weight) was administered to pregnant mice (C57BL/6Cr) every 3 days by gavage from gestational day (GD) 6 to postnatal day (PND) 20. Compared with the control, treatment with A1254 did not alter the maternal body weight during the gestation and lactation periods. The body weight of the offspring did not differ among treatments. To assess the effects on offspring following such exposure, physical and neurobehavioral development (i.e., pinna detachment, hair growth, eye opening, incisor eruption, grasp reflex, righting reflex, walking, negative geotaxis, and cliff avoidance) was observed before weaning. At PND 7, poor adult-like responses in negative geotaxis were observed in all exposed groups. When the offspring were at 8-week old, the PCB-treated (18 mg/kg body weight) mice showed a decreased walking speed in the open-field test, and a prolonged time to reach the platform in the water maze test. Spontaneous locomotion activity was not affected by PCB exposure at 9 weeks . These results showed that perinatal exposure to PCBs produces several behavioral alterations in mice. Although dose-dependent changes were not observed, the neurobehavioral effects such as a decreased walking speed in the open-field test and a prolonged time to reach the platform in the water maze test remained in adulthood after the seeming recovery from the transient delay in development before weaning.

  13. Polychlorinated biphenyls (PCB) analysis report for solid sample for 219S tank 102

    International Nuclear Information System (INIS)

    Ross, G.A.

    1997-01-01

    One waste sample was analyzed (with duplicate, matrix spike, and matrix spike duplicate) for PCBs as Aroclor mixtures by the Inorganic/Organic Chemistry Group. A soxhlet extraction procedure was used for extraction of the Aroclors from the sample. Analysis was performed using dual column confirmation gas chromatography/electron capture detection (GC/ECD). Extraction follows closely method 354 C of SW-846, analysis follows SW-846 method 8082. A cross reference of laboratory sample number to the customer identification is given in a table

  14. Polychlorinated biphenyls (PCB) analysis report for solid sample from 219S tank 104

    International Nuclear Information System (INIS)

    Ross, G.A.

    1998-01-01

    A sample of solids was obtained from tank 104 of 219S via a peristaltic pump equipped with a stainless steel tube and Norprenel tubing (Phthalate free). The sample obtained in a glass jar with Teflon 2 lid, was analyzed for PCBs as Aroclor mixtures. A soxhlet extraction procedure was used to extract the Aroclors from the sample. Analysis was performed using dual column confirmation gas chromatography/electron capture detection (GC/ECD). The extraction method closely follows SW-846 method 3540C and the analysis follows SW-846 method

  15. Polychlorinated biphenyls (PCB) analysis report for solid sample from 219S tank 101

    International Nuclear Information System (INIS)

    Diaz, L.A.

    1998-01-01

    One waste sample that was obtained with solids from tank 101 of 219S via a peristaltic pump equipped with a stainless steel tube and Norprene tubing (Phthalate free) was obtained in a glass jar with teflon lid was analyzed (with duplicate, matrix spike, and matrix spike duplicate) for PCBs as Aroclor mixtures by the Inorganic/Organic Chemistry Group. A soxhlet extraction procedure was used for extraction of the Aroclors from the sample. Analysis was performed using dual column confirmation gas chromatography/electron capture detection (GC/ECD). Results are presented

  16. Isolation and characterisation of polychlorinated biphenyl (PCB degrading fungi from a historically contaminated soil

    Directory of Open Access Journals (Sweden)

    Di Toro Sara

    2009-01-01

    Full Text Available Abstract Background Polychlorinated biphenyls (PCBs are widespread toxic pollutants. Bioremediation might be an effective, cost competitive and environment-friendly solution for remediating environmental matrices contaminated by PCBs but it is still unsatisfactory, mostly for the limited biodegradation potential of bacteria involved in the processes. Very little is known about mitosporic fungi potential in PCB bioremediation and their occurrence in actual site historically contaminated soils. In the present study, we characterised the native mycoflora of an aged dump site soil contaminated by about 0.9 g kg-1 of Aroclor 1260 PCBs and its changing after aerobic biotreatment with a commercial complex source of bacteria and fungi. Fungi isolated from the soil resulting from 120 days of treatment were screened for their ability to adsorb or metabolise 3 target PCBs. Results The original contaminated soil contained low loads of few fungal species mostly belonging to the Scedosporium, Penicillium and Aspergillus genera. The fungal load and biodiversity generally decreased throughout the aerobic treatment. None of the 21 strains isolated from the treated soil were able to grow on biphenyl (200 mg L-1 or a mixture of 2-chlorobiphenyl, 4,4'-dichlorobiphenyl and 2,2',5,5'-tetrachlorobiphenyl (20 mg L-1 each as sole carbon sources. However, 16 of them grew in a mineral medium containing the same PCBs mixture and glucose (10 g L-1. Five of the 6 isolates, which displayed the faster and more extensive growth under the latter conditions, were found to degrade the 3 PCBs apparently without the involvement of ligninolytic enzymes; they were identified as Penicillium chrysogenum, Scedosporium apiospermum, Penicillium digitatum and Fusarium solani. They are the first PCB degrading strains of such species reported so far in the literature. Conclusion The native mycoflora of the actual site aged heavily contaminated soil was mainly constituted by genera often

  17. Effects of urbanization on gaseous and particulate polycyclic aromatic hydrocarbons and polychlorinated biphenyls in a coastal city, China: levels, sources, and health risks.

    Science.gov (United States)

    Hong, Youwei; Chen, Jinsheng; Zhang, Fuwang; Zhang, Han; Xu, Lingling; Yin, Liqian; Chen, Yanting

    2015-10-01

    Gas/particle distributions of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) were measured in Xiamen from May 2009 to March 2010 to evaluate the impacts of urbanization on the fate of persistent organic pollutants (POPs) in the atmospheric environment. In a newly developing area (NDA), the concentrations of 16 PAHs (gas + particle) were significantly higher than that a historically urbanized area (HUA) (p value <0.05), while the trend of 28 PCBs was reversed. Diagnostic ratios and principle component analysis (PCA) implied that atmospheric PAHs in the NDA were mainly derived from petrogenic combustion, including mixed sources of vehicle emissions, biomass burning and oil combustion, while pyrogenic combustion (e.g., traffic and coal combustion) was considered the major source of PAHs in the HUA. Atmospheric PCBs in both HUA and NDA were dominated by TriCBs and PeCBs related to the use of commercial mixtures (Aroclors 1242 and 1254). Based on the toxicological equivalent factor (TEF) approach, total benzo[a]pyrene equivalent values in the HUA and NDA were 1.12 and 2.02 ng m(-3), respectively, exceeding the standard threshold values (1.0 ng m(-3)) of China and WHO. Average daily intake of dioxin-like compounds was 0.2 pg kg(-1) day(-1) in the HUA, which are below the WHO tolerable daily intake level. The results showed that the contribution to the toxic equivalency (TEQ) was dominated by PCB169, PCB105, and PCB81.

  18. Levels of polychlorinated biphenyls and pesticides in bluefish before and after cooking.

    Science.gov (United States)

    Trotter, W J; Corneliussen, P E; Laski, R R; Vannelli, J J

    1989-01-01

    Similar levels of polychlorinated biphenyls (PCBs), pesticides, and fat were found in 20 correlated uncooked and cooked (baked) bluefish fillets. Fillets averaged 2.5 ppm PCBs as Aroclor 1254 (whole basis) before cooking; after cooking, with the oil drippings and skin discarded, the average PCB level was 2.7 ppm. Although PCBs, lipophilic pesticides, and fat were lost along with oil drippings and skin that were discarded after cooking, the moisture loss in the fillets during cooking compensated for these weight losses almost completely. After the fillets were cooked and the oil drippings and skin were discarded, the PCB content of the fillets was 27% lower on the average.

  19. Geographic specificity of Aroclor 1268 in bottlenose dolphins (Tursiops truncatus) frequenting the Turtle/Brunswick River Estuary, Georgia (USA)

    International Nuclear Information System (INIS)

    Pulster, Erin L.; Maruya, Keith A.

    2008-01-01

    Coastal marine resources are at risk from anthropogenic contaminants, including legacy persistent organic pollutants (POPs) with half-lives of decades or more. To determine if polychlorinated biphenyl (PCB) signatures can be used to distinguish among local populations of inshore bottlenose dolphins (Tursiops truncatus) along the southeastern U.S. coast, blubber from free-ranging and stranded animals were collected along the Georgia coast in 2004 and analyzed for PCB congeners using gas chromatography with electron capture and negative chemical ionization mass spectrometric detection (GC-ECD and GC-NCI-MS). Mean total PCB concentrations (77 ± 34 μg/g lipid) were more than 10 fold higher and congener distributions were highly enriched in Cl 7 -Cl 10 homologs in free-ranging animals from the Turtle/Brunswick River estuary (TBRE) compared with strandings samples from Savannah area estuaries 90 km to the north. Using principal components analysis (PCA), the Aroclor 1268 signature associated with TBRE animals was distinct from that observed in Savannah area animals, and also from those in animals biopsied in other southeastern U.S estuaries. Moreover, PCB signatures in dolphin blubber closely resembled those in local preferred prey fish species, strengthening the hypothesis that inshore T. truncatus populations exhibit long-term fidelity to specific estuaries and making them excellent sentinels for assessing the impact of stressors on coastal ecosystem health

  20. Geographic specificity of Aroclor 1268 in bottlenose dolphins (Tursiops truncatus) frequenting the Turtle/Brunswick River Estuary, Georgia (USA)

    Energy Technology Data Exchange (ETDEWEB)

    Pulster, Erin L. [Marine Sciences Department, Savannah State University, Savannah, Georgia, 31404 (United States); Skidaway Institute of Oceanography, 10 Ocean Science Circle, Savannah, Georgia, 31411 (United States)], E-mail: epulster@mote.org; Maruya, Keith A. [Skidaway Institute of Oceanography, 10 Ocean Science Circle, Savannah, Georgia, 31411 (United States)

    2008-04-15

    Coastal marine resources are at risk from anthropogenic contaminants, including legacy persistent organic pollutants (POPs) with half-lives of decades or more. To determine if polychlorinated biphenyl (PCB) signatures can be used to distinguish among local populations of inshore bottlenose dolphins (Tursiops truncatus) along the southeastern U.S. coast, blubber from free-ranging and stranded animals were collected along the Georgia coast in 2004 and analyzed for PCB congeners using gas chromatography with electron capture and negative chemical ionization mass spectrometric detection (GC-ECD and GC-NCI-MS). Mean total PCB concentrations (77 {+-} 34 {mu}g/g lipid) were more than 10 fold higher and congener distributions were highly enriched in Cl{sub 7}-Cl{sub 10} homologs in free-ranging animals from the Turtle/Brunswick River estuary (TBRE) compared with strandings samples from Savannah area estuaries 90 km to the north. Using principal components analysis (PCA), the Aroclor 1268 signature associated with TBRE animals was distinct from that observed in Savannah area animals, and also from those in animals biopsied in other southeastern U.S estuaries. Moreover, PCB signatures in dolphin blubber closely resembled those in local preferred prey fish species, strengthening the hypothesis that inshore T. truncatus populations exhibit long-term fidelity to specific estuaries and making them excellent sentinels for assessing the impact of stressors on coastal ecosystem health.

  1. Source determination of highly chlorinated biphenyl isomers in pine needles - Comparison to several PCB preparations

    International Nuclear Information System (INIS)

    Wyrzykowska, Barbara; Bochentin, Ilona; Hanari, Nobuyasu; Orlikowska, Anna; Falandysz, Jerzy; Yuichi, Horii; Yamashita, Nobuyoshi

    2006-01-01

    The isomer specific composition of 13 technical PCB formulations of different origin and of pine needles was analyzed using GC/MS and HRGC/HRMS. Nonachlorinated biphenyls were identified in 11 among 13 formulations analyzed, with the highest abundance found for highly chlorinated ones (Aroclors 1268 and 1260, Chlorofen, Sovol, Kanechlors 600 and 500, Delor 106, Clophen A60). Decachlorobiphenyl was identified only in Aroclor 1268, Clophen A60, Aroclor 1260 and Chlorofen, comprising, respectively, 8.9, 2.8, 1.3 and 0.82% of the total bulk of nona- and decaCBs detected. Nona- and decaCB were detected in pine needles in Poland with the highest concentrations found at the sites neighboring to a former production sites of the Polish PCB formulations, while in pine needles collected around the Tokyo Bay nona- and decacCB were detected only in four of 10 sites and the concentrations corresponded to those found at the rural areas of Poland. - Pine needles were suitable as passive samplers for PCBs in air

  2. Polychlorinated biphenyls in surface soil in urban and background areas of Mongolia

    International Nuclear Information System (INIS)

    Mamontova, Elena A.; Mamontov, Alexander A.; Tarasova, Eugenia N.; Kuzmin, Mikhail I.; Ganchimeg, Darmaa; Khomutova, Marina Yu.; Gombosuren, Odontuya; Ganjuurjav, Erdenebayasgalan

    2013-01-01

    Polychlorinated biphenyls (PCBs) were measured in soil in some industrial towns (Ulaanbaatar, Suhbaatar, Erdenet, Darhan, Tsetserleg, Hovd, Ulaangom, Altay, Bayanhongor, Arvayheer, Saynshand, Choybalsan) and in background and rural areas of Mongolia. The average sum of all investigated PCB congeners in soil of Mongolia comes to 7.4 ng/g dry weight (DW) and varies from 0.53 ng/g DW till 114 ng/g DW. PCB levels in soil from towns are significantly higher than those in soil from background and rural areas. The PCB homological composition in soil sampled in highly-PCB-polluted sites is similar to the PCB homological pattern in Sovol and Aroclor 1254. Significant correlation between soil organic carbon and low chlorinated PCB both for towns and background sites was found. Significant differences in PCB means in soil in different natural zones were found. -- Highlights: •First study to measure PCBs in surface soil sampled throughout Mongolia. •The PCB patterns in polluted soil were similar to those in Sovol or Aroclor 1254. •Significant differences in PCB means in soil in different natural zones were found. -- Polychlorinated biphenyls were measured in soils throughout Mongolia

  3. Fatty acid alterations caused by PCBs (Aroclor 1242) and copper in adipose tissue around lymph nodes of mink

    International Nuclear Information System (INIS)

    Kaekelae, R.; Hyvaerinen, H.

    1999-01-01

    Fatty acid composition was determined in adipose tissue surrounding the mesenteric lymph nodes of mink (Mustela vison) exposed to polychlorinated biphenyls (PCBs: 1 mg Aroclor 1242 in food day -1 for 28 days) and/or copper (62 mg kg -1 food). These specific adipose tissues are known to have functional relationships with lymphocytes, and proliferation of cultured lymphocytes is influenced by the quality of fatty acids available in media. In six experimental groups the diet was based on freshwater fish, and in two groups it was based on marine fish. These basal diets differed in terms of fatty acid composition and content of fat-soluble vitamins A 1 and E. The fatty acid composition of membrane phospholipids (PL) responded to PCBs more than that of triacylglycerols (TG). The effects of copper were small. In female minks fed a diet of freshwater fish, the proportion of highly unsaturated fatty acids in PL decreased by 5 wt.% due to PCBs, and the acids seemed to be replaced by monounsaturated fatty acids (9 wt.% increase of total). This decrease of highly unsaturated fatty acids in PL was milder in minks on the marine fish diet rich in fat-soluble vitamins. In TG of minks on the marine diet, however, PCBs decreased the proportion of docosahexaenoic acid (22:6n-3). The possibility that these alterations in the fatty acid metabolism of adipose tissue supporting the lymph nodes affect immune function during PCB exposure should be studied further. Interestingly, the quality of the fish diet affected the magnitude of the alterations. The fatty acid responses may also differ between males and females. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  4. Gas-particle distributions, sources and health effects of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs) in Venice aerosols.

    Science.gov (United States)

    Gregoris, Elena; Argiriadis, Elena; Vecchiato, Marco; Zambon, Stefano; De Pieri, Silvia; Donateo, Antonio; Contini, Daniele; Piazza, Rossano; Barbante, Carlo; Gambaro, Andrea

    2014-04-01

    Air samples were collected in Venice during summer 2009 and 2012 to measure gas and particulate concentrations of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs). PCB-11, considered a marker for non-Aroclor contamination of the environment, was found for the first time in the Venetian lagoon and in Europe. An investigation on sources has been conducted, evidencing traffic as the major source of PAHs, whereas PCBs have a similar composition to Aroclor 1248 and 1254; in 2009 a release of PCN-42 has been hypothesized. Toxicological evaluation by TCA and TEQ methods, conducted for the first time in Venice air samples, identified BaP, PCB-126 and PCB-169 as the most important contributors to the total carcinogenic activity of PAHs and the total dioxin-like activity of PCBs and PCNs. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Aroclor-1254, a developmental neurotoxicant, alters energy metabolism-and intracellular signaling-associated protein networks in rat cerebellum and hippocampus

    Science.gov (United States)

    The vast literature on the mode of action of polychlorinated biphenyls (PCBs) indicates that PCBs are a unique model for understanding the mechanisms of toxicity of environmental mixtures of persistent chemicals. PCBs have been shown to adversely affect psychomotor function and l...

  6. New antibody and immunoassay pretreatment strategy to screen polychlorinated biphenyls in Korean transformer oil.

    Science.gov (United States)

    Terakado, Shingo; Ohmura, Naoya; Park, Seok-Un; Lee, Seung-Min; Glass, Thomas R

    2013-01-01

    Development and modifications are described that expand the application of an immunoassay from the detection of Kanechlors (Japanese technical PCBs mixtures) to the detection of Aroclors (U. S. technical PCB mixtures, used in Korea) in contaminated Korean transformer oil. The first necessary modification was the development of a new antibody with a reactivity profile favorable for Aroclors. The second modification was the addition of a second column to the solid-phase extraction method to reduce assay interference caused by the Korean oil matrix. The matrix interference is suspected to be caused by the presence of synthetic oils (or similar materials) present as contaminants. The modified assay was validated by comparison to high-resolution gas chromatography/high-resolution mass spectrometry analysis, and was shown to be tolerant of up to 10% of several common synthetic insulating oils. Finally the screening performance of the modified assay was evaluated using 500 used transformer oil samples of Korean origin, and was shown to have good performance in terms of false positive and false negative rates. This report provides evidence for the first establishment of immunoassay screening for Aroclor based PCB contamination in Korean transformer oil.

  7. Optical detection of polychlorinated biphenyls

    Science.gov (United States)

    Kuncova, Gabriela; Berkova, Daniela; Burkhard, Jiri; Demnerova, Katerina; Pazlarova, Jarmila; Triska, Jan; Vrchotova, Nadezda

    1999-12-01

    In this paper we describe the detection of polychlorinated biphenyls (PCBs) which is based on the measurement of changes of optical absorption at 400 nm of the medium in an aerobic bioreactor with immobilized cells Pseudomonas species 2. The rate of production, composition and the concentration of yellow intermediates are influenced by concentration and composition of PCB mixtures, concentration of cells and by the methods of immobilization. The method was applied in the detection of commercial mixture D103. It was found that the advantageous carriers were inorganic or organic-inorganic matrices, which sorbed PCBs and a cell outgrowth from their surface was low. In water contaminated with transformer oil and chlorinated hydrocarbons the detection limit is 10-2 gD103/kg. In transformer oil the upper limit for degradation of D103 by sodium dehalogenation (1.5 gD103 /kgoil) was determined also in the presence of the same concentration of trichloroethylene. The employment to of a liquid core waveguide spectrophotometer instead of a diode array spectrophotometer increased the sensitivity of the measurement of yellow intermediates by a factor of 100. An extrinsic fiber-optic sensor was used for in-situ measurement during biodegradation of PCBs in bioreactors.

  8. Effects of perinatal coexposure to methylmercury and polychlorinated biphenyls on neurobehavioral development in mice

    Energy Technology Data Exchange (ETDEWEB)

    Sugawara, Norio [Tohoku University School of Medicine, Environmental Health Sciences, Aoba-ku, Sendai (Japan); Hirosaki University Graduate School of Medicine, Department of Neuropsychiatry, Hirosaki (Japan); Ohba, Takashi; Nakai, Kunihiko; Nakamura, Tomoyuki; Suzuki, Keita; Kameo, Satomi; Shimada, Miyuki; Kurokawa, Naoyuki; Satoh, Chieko; Satoh, Hiroshi [Tohoku University School of Medicine, Environmental Health Sciences, Aoba-ku, Sendai (Japan); Kakita, Akiyoshi [Niigata University, Department of Pathological Neuroscience, Resource Branch for Brain Disease Research, Brain Research Institute, Niigata (Japan)

    2008-06-15

    Methylmercury (MeHg) and polychlorinated biphenyls (PCBs) are environmental pollutants that cause neurobehavioral deficits in humans. Because exposures to MeHg and PCBs occur through fish consumption, it is necessary to clarify the effects of the interaction of the two pollutants. Therefore, we investigated the effects of perinatal exposure to MeHg and PCBs on the neurobehavioral development in mice. Female mice (C57BL/6Cr) were divided into four groups according to the type of exposure: (1) vehicle control, (2) MeHg alone, (3) PCBs alone, and (4) MeHg + PCBs. The MeHg-exposed groups were fed with a diet containing 5 ppm MeHg (as Hg), from 4 weeks before mating, throughout pregnancy, and lactation. The PCB-exposed groups were given a commercial mixture of PCBs, Aroclor 1254, at 18 mg/kg body weight in corn oil by gavage every 3 days from day 5 after breeding and continued until postnatal day (PND) 20. Before weaning, an assessment of eye opening showed the interactive effects between MeHg and PCBs on PND 12: The coexposure group showed a similar response to the control group, whereas the MeHg- and PCB-exposed groups showed a high response than the former two groups. We also observed delay in development of grasp reflex by MeHg exposure on PNDs 12 and 14. When the offspring mice were 8 weeks old, the group exposed to PCBs alone showed increases in the frequencies of excrement defecation and urine traces in an open-field test. Analysis of the latency revealed the antagonistic interaction between the MeHg and PCBs: The latency increased by either MeHg or PCB exposure was decreased by coexposure. Treatment with MeHg decreased the distance walked by the mice, and MeHg interacted with PCBs. Moris' water maze test showed that the MeHg-treated mice took a long time to reach the submerged platform; however, this MeHg exposure showed no interaction with PCB exposure. The spontaneous locomotion activity of the mice was not affected by the chemical exposure at 9 weeks of

  9. Aqueous exposure to Aroclor 1254 modulates the mitogenic response of Atlantic salmon anterior kidney T-cells: Indications of short- and long-term immunomodulation

    International Nuclear Information System (INIS)

    Iwanowicz, Luke R.; Lerner, Darren T.; Blazer, Vicki S.; McCormick, Stephen D.

    2005-01-01

    Polychlorinated biphenyls (PCBs) exist as persistent organic pollutants in numerous river systems in the United States. Unfortunately, some of these rivers are sites of active Atlantic salmon restoration programs, and polychlorinated biphenyls have been implicated as ancillary factors contributing to failed salmon restoration. Here, we investigate the immediate and chronic effects of intermediate duration aqueous PCB exposure (1 or 10 μg L -1 Aroclor 1254) on the mitogen-stimulated lymphoproliferative response of Atlantic salmon anterior kidney leukocytes (AKLs). A short-term study was designed to examine immunomodulation in Atlantic salmon smolts immediately following 21 days of aqueous exposure, while a long-term study evaluated chronic impacts in the mitogen response in parr 15 months post-exposure as larvae. The proliferative response of AKLs to the mitogens concanavalin A (CON A), phytohemaglutinnin-P (PHA-P), pokeweed mitogen (PWM), and lipopolysaccharide were used as an indice of immunomodulation. The proliferative response to the T-cell mitogens CON A and PHA-P was significantly increased in the 10 μg L -1 group (n = 10; P = 0.043 and 0.002, respectively) immediately following exposure of smolts. Additionally, The PHA-P response was significantly increased in the 1 μg L -1 exposure group (n = 10, P = 0.036). In fish treated as larvae and tested 15 months later, the PHA-P sensitive populations exhibited elevated proliferation in the 1 and 10 μg L -1 groups (n = 12, P -1 treated groups. These results demonstrate an immunomodulatory effect of PCBs on T-cell mitogen sensitive populations of lymphocytes in Atlantic salmon as well as long-term immunomodulation in PHA-P and PWM sensitive populations

  10. Aqueous exposure to Aroclor 1254 modulates the mitogenic response of Atlantic salmon anterior kidney T-cells: indications of short- and long-term immunomodulation.

    Science.gov (United States)

    Iwanowicz, Luke R; Lerner, Darren T; Blazer, Vicki S; McCormick, Stephen D

    2005-05-15

    Polychlorinated biphenyls (PCBs) exist as persistent organic pollutants in numerous river systems in the United States. Unfortunately, some of these rivers are sites of active Atlantic salmon restoration programs, and polychlorinated biphenyls have been implicated as ancillary factors contributing to failed salmon restoration. Here, we investigate the immediate and chronic effects of intermediate duration aqueous PCB exposure (1 or 10 microgL-1 Aroclor 1254) on the mitogen-stimulated lymphoproliferative response of Atlantic salmon anterior kidney leukocytes (AKLs). A short-term study was designed to examine immunomodulation in Atlantic salmon smolts immediately following 21 days of aqueous exposure, while a long-term study evaluated chronic impacts in the mitogen response in parr 15 months post-exposure as larvae. The proliferative response of AKLs to the mitogens concanavalin A (CON A), phytohemaglutinnin-P (PHA-P), pokeweed mitogen (PWM), and lipopolysaccharide were used as an indice of immunomodulation. The proliferative response to the T-cell mitogens CON A and PHA-P was significantly increased in the 10 microgL-1 group (n=10; P=0.043 and 0.002, respectively) immediately following exposure of smolts. Additionally, The PHA-P response was significantly increased in the 1 microgL-1 exposure group (n=10, P=0.036). In fish treated as larvae and tested 15 months later, the PHA-P sensitive populations exhibited elevated proliferation in the 1 and 10 microgL-1 groups (n=12, P<0.04) relative to the vehicle control while the PWM response was significantly increased (n=12, P=0.036) only in the 10 microgL-1 treated groups. These results demonstrate an immunomodulatory effect of PCBs on T-cell mitogen sensitive populations of lymphocytes in Atlantic salmon as well as long-term immunomodulation in PHA-P and PWM sensitive populations.

  11. The metabolism of biphenyl

    International Nuclear Information System (INIS)

    Meyer, T.; Aarbakke, J.; Scheline, R.R.

    1976-01-01

    The metabolic disposition of 14 C-biphenyl in the rat was studied by liquid scintillation counting. The rats were given an oral dose of 14 C-biphenyl (100 mg/kg, 0.7-1.0 μci) and the total excretion of radioactivity after 96 hrs was 92.2% of the dose. Urinary excretion accounted for 84.8% and faecal excretion for 7.3% of the dose. Most of this radioactivity, 75.8% and 5.8% respectively, was excreted within 24 hrs. Only trace amounts of 14 CO 2 were detected in the expired air and 0.6% of the dose was found to be still present in the rats 96 hrs after biphenyl administration. Extraction and fractionation of the 24 hrs urine samples showed that the largest fraction (nearly 30% of the dose) consisted of conjugated phenolic metabolites. Acidic metabolites accounted for a quarter of the dose and the low levels of expired 14 CO 2 indicated that these were not products resulting from extensive degradation and decarboxylation. (author)

  12. Polychlorinated biphenyl congener patterns in fish near the Hanford Site (Washington State, USA).

    Science.gov (United States)

    Rodenburg, Lisa A; Delistraty, Damon; Meng, Qingyu

    2015-03-03

    It is well-known that absorption, distribution, metabolism, and excretion (ADME) processes in fish can alter polychlorinated biphenyl (PCB) congener patterns in fish, but these patterns have never been investigated using an advanced source-apportionment tool. In this work, PCB congener patterns in freshwater fish were examined with positive matrix factorization (PMF). PCB congeners were quantified via EPA Method 1668 in fillet and carcass of six species in four study areas in the Columbia River near the Hanford Site. Six factors were resolved with PMF2 software. Depletion and enhancement of PCB congeners in factors, relative to Aroclor 1254, suggested biotransformation (via cytochrome P450) and bioaccumulation in fish, respectively. Notable differences were observed among species and across study locations. For example, sturgeon and whitefish exhibited congener patterns consistent with Aroclor weathering, suggesting potential PCB metabolism in these species. In terms of location, average concentration of total PCBs for all species combined was significantly higher (P < 0.05) at Hanford 100 and 300 areas, relative to upriver and downriver study sites. Furthermore, a distinct PCB signature in sturgeon and whitefish, collected at Hanford study areas, suggests that Hanford is a unique PCB source.

  13. Non-Dioxin-Like PCBs: Effects and Consideration In Ecological Risk Assessment

    Science.gov (United States)

    An estimated one million metric tons of commercial mixtures of polychlorinated biphenyls (PCBs), such as Aroclors (USA), Kanechlors (Japan) and Clophens (Germany), were manufactured (WHO, 1993) and used worldwide as dielectric fluids

  14. Proteomic strategy for the analysis of the polychlorobiphenyl-degrading cyanobacterium Anabaena PD-1 exposed to Aroclor 1254.

    Directory of Open Access Journals (Sweden)

    Hangjun Zhang

    Full Text Available The cyanobacterium Anabaena PD-1, which was originally isolated from polychlorobiphenyl (PCB-contaminated paddy soils, has capabilities for dechlorinatin and for degrading the commercial PCB mixture Aroclor 1254. In this study, 25 upregulated proteins were identified using 2D electrophoresis (2-DE coupled with matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS. These proteins were involved in (i PCB degradation (i.e., 3-chlorobenzoate-3,4-dioxygenase; (ii transport processes [e.g., ATP-binding cassette (ABC transporter substrate-binding protein, amino acid ABC transporter substrate-binding protein, peptide ABC transporter substrate-binding protein, putrescine-binding protein, periplasmic solute-binding protein, branched-chain amino acid uptake periplasmic solute-binding protein, periplasmic phosphate-binding protein, phosphonate ABC transporter substrate-binding protein, and xylose ABC transporter substrate-binding protein]; (iii energetic metabolism (e.g., methanol/ethanol family pyrroloquinoline quinone (PQQ-dependent dehydrogenase, malate-CoA ligase subunit beta, enolase, ATP synthase β subunit, FOF1 ATP synthase subunit beta, ATP synthase α subunit, and IMP cyclohydrolase; (iv electron transport (cytochrome b6f complex Fe-S protein; (v general stress response (e.g., molecular chaperone DnaK, elongation factor G, and translation elongation factor thermostable; (vi carbon metabolism (methanol dehydrogenase and malate-CoA ligase subunit beta; and (vii nitrogen reductase (nitrous oxide reductase. The results of real-time polymerase chain reaction showed that the genes encoding for dioxygenase, ABC transporters, transmembrane proteins, electron transporter, and energetic metabolism proteins were significantly upregulated during PCB degradation. These genes upregulated by 1.26- to 8.98-fold. These findings reveal the resistance and adaptation of cyanobacterium to the presence of PCBs, shedding light on the

  15. Effects of Aroclor 1242 and different fish-based diets on vitamins A(retinol) and A2 (3,4-didehydroretinol), and their fatty acyl esters in mink plasma

    International Nuclear Information System (INIS)

    Kaekelae, Anne; Kaekelae, Reijo; Hyvaerinen Heikki; Nieminen, Petteri

    2003-01-01

    The effects of a 21-week exposure to Aroclor 1242 (1 mg per day in feed on plasma concentrations of vitamins A 1 (retinol) and A(3,4-didehydroretinol) and their principal fatty acyl esters (A 1 -16:0 A 2 -16:0 (palmitates), A 1 -18:1n-9; A 2 -18:1n-9 (oleates), and A 1 -18:0 A 2 -18:0 (stearates)) were studied in young female mink (Mustela vison) fed a diet based on freshwater smelt. These vitamin levels were also examined in mink fed diets containing Baltic herring or fatty marine fish. In the Aroclor-exposed smelt-fed mink, the plasma concentrations of A 1 and Aesters were significantly lower than the levels in controls fed the uncontaminated smelt diet. In addition, the A 2 esters reacted mor sensitively to the polychlorinated biphenyls than did A 1 esters. I contrast, in the plasma of the exposed mink the level of alcoholic A 1 was normal, and transport of thyroxine (T 4 ) and nonspecific lipoprotei transport of major lipids were not impaired. Despite the large dietary supply of vitamin A 2 and high levels of plasma A 2 esters, the mink fed freshwate smelt had only trace amounts of alcoholic vitamin A 2 in their plasma. The concentrations of A 1 and A 2 esters in the plasma of all the mink studied correlated with the hepatic total concentrations of the vitamins. Thus, in carnivores that have nonspecific lipoprotein transport of vitamin A esters determination of plasma levels of the esterified vitamins may be a useful nondestructive way to estimate stores of the vitamin A analogs in the body and to assess the organochlorine-induced decrease in the vitamin stores

  16. Development of a Multianalyte Enzyme-Linked Immunosorbent Assay for Permethrin and Aroclors and Its Implementation for Analysis of Soil/Sediment and House Dust ExtractsExtracts

    Science.gov (United States)

    Development of a multianalyte enzyme-linked immunosorbent assay (ELISA) for detection of permethrin and aroclors 1248 or 1254, and implementation of the assay for analysis of soil/sediment samples are described. The feasibility of using the multianalyte ELISA to monitor aroclors ...

  17. K Basin sludge polychlorinated biphenyl removal technology assessment

    International Nuclear Information System (INIS)

    Ashworth, S.C.

    1998-01-01

    The two Hanford K Basins are water-filled concrete pools that contain over 2,100 metric tons of N Reactor fuel elements stored in aluminum or stainless steel canisters. During the time the fuel has been stored, approximately 50 m3 of heterogeneous solid material have accumulated in the basins. This material, referred to as sludge, is a mixture of fuel corrosion products, metallic bits of spent fuel and zirconium clad iron and metal corrosion products and silica from migrating sands. Some of the sludges also contain PCBs. The congener group of PCBs was identified as Aroclor 1254. The maximum concentration of sludge PCBS was found to be 140 ppm (as settled wet basis). However, the distribution of the PCBs is non-uniform throughout the sludge (i.e., there are regions of high and low concentrations and places where no PCBs are present). Higher concentrations could be present at various locations. Aroclors 1016/1242, 1221, 1248, 1254, and 1260 were identified and quantified in K West (KW) Canister sludge. In some of these samples, the concentration of 1260 was higher than 1254. The sludge requires pre-treatment to meet tank farm waste acceptance criteria, Among the numerous requirements, the sludge should be retreated so that it does not contain regulated levels of Toxic Substances Control Act (TSCA) compounds. Because of their stable chemistry and relative insolubility in water, PCBs are difficult to treat. They also resist degradation from heat and electrical charges. This stability has resulted in environmental persistence which has prompted the development of a variety of new cleanup processes including supercritical processes, advanced oxidation, dehalogenation and others. Hopefully, most of the new processes are discussed herein. Information on new processes are being received and will be evaluated in a future revision

  18. Simultaneous quantification of T4, T3, rT3, 3,5-T2 and 3,3'-T2 in larval zebrafish (Danio rerio) as a model to study exposure to polychlorinated biphenyls.

    Science.gov (United States)

    Chen, Xiaopeng; Walter, Kyla M; Miller, Galen W; Lein, Pamela J; Puschner, Birgit

    2018-06-01

    Environmental toxicants that interfere with thyroid hormone (TH) signaling can impact growth and development in animals and humans. Zebrafish represent a model to study chemically induced TH disruption, prompting the need for sensitive detection of THs. Simultaneous quantification of 3,3',5-triiodo-l-thyronine (T3), thyroxine (T4), 3,3',5'-triiodo-l-thyronine (rT3), 3,5-diiodo-l-thyronine (3,5-T2) and 3,3'-diiodo-l-thyronine (3,3'-T2) in zebrafish larvae was achieved by ultra-performance liquid chromatography-tandem mass spectrometry in positive ion mode. Solid-phase extraction with SampliQ cartridges and derivatization with 3 m hydrochloric acid in n-butanol reduced matrix effects. Derivatized compounds were separated on an Acquity UPLC BEH C 18 column with mobile phases consisting of 0.1% acetic acid in deionized water and 0.1% acetic acid in methanol. The limits of detection ranged from 0.5 to 0.6 pg injected on column. The method was validated by evaluating recovery (77.1-117.2%), accuracy (87.3-123.9%) and precision (0.5-12.4%) using diluted homogenized zebrafish embryos spiked with all target compounds. This method was then applied to zebrafish larvae collected after 114 h of exposure to polychlorinated biphenyls (PCBs), including PCB 28, PCB 66 and PCB 95, or the technical mixture Aroclor 1254. Exposure to PCB 28 and PCB 95 increased the T4:T3 ratio and decreased the T3:rT3 ratio, demonstrating that this method can effectively detect PCB-induced alterations in THs. Copyright © 2018 John Wiley & Sons, Ltd.

  19. Ecotoxicity and risk to human fish consumers of polychlorinated biphenyls in fish near the Hanford Site (USA).

    Science.gov (United States)

    Delistraty, Damon

    2013-02-15

    The purpose of this study was to quantify three groups of polychlorinated biphenyl (PCB) congeners (i.e., dioxin-like toxic equivalents [TEQ], non-dioxin-like PCBs, total PCBs) in fish in several species, tissues, and locations in the Columbia River near the Hanford Site. For TEQ and total PCBs, fish ecotoxicity and risk to human fish consumers were also evaluated. Non-dioxin-like PCBs were not assessed for toxicity, due to lack of available benchmarks. In sturgeon liver, TEQ was significantly higher (Pfillet than in other species (except carp) and significantly higher (Pfillet, relative to bass. All PCB residues in carcass were significantly elevated (Pfillet. In addition to PCB source, many factors (e.g., dietary composition, tissue lipid content, fish mobility and home range, age, toxicokinetic processes, seasonal adaptations) influence patterns in PCB bioaccumulation across species, tissues, and locations. TEQ and total PCB residues in liver, fillet, and carcass, observed in this study, were below corresponding no effect residues for TEQ and Aroclors in the literature for fish survival, growth, and reproduction. In contrast, TEQ and total PCBs in fillet in this study exceeded USEPA tissue screening levels for cancer (1E-6 risk) and noncancer (hazard quotient [HQ]=1) toxicity for human fish consumers. Key uncertainties in these comparisons to assess toxicity relate to variation in fish species sensitivity to PCBs and use of Aroclor data in the literature to represent total PCBs. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. New evidences of neurotoxicity of aroclor 1254 in mice brain: potential of coenzyme q10 in abating the detrimental outcomes

    Directory of Open Access Journals (Sweden)

    Anuradha Majumdar

    2014-03-01

    Full Text Available Objectives The present subacute study was designed to evaluate the effect of coenzyme Q 10 (CoQ10 in the 28 days aroclor 1254 exposure induced oxidative stress in mice brain. Methods Biochemical estimations of brain lipid peroxidation (LPO, reduced glutathione (GSH, and activities of superoxide dismutase (SOD, catalase (CAT, glutathione peroxidase (GPx and acetyl cholinesterase (AChE, and histopathological investigations of brain tissue were carried out. Results Oral exposure of aroclor 1254 (5 mg/kg led to significant decrease in levels of GSH, and activities of SOD, CAT, GPx, and AChE, and increase in LPO. These aberrations were restored by CoQ10 (10 mg/kg, intraperitoneal injection [IP]. This protection offered was comparable to that of L-deprenyl (1 mg/kg, IP which served as a reference standard. Conclusions Aroclor 1254 exposure hampers the activities of various antioxidant enzymes and induces oxidative stress in the brains of Swiss albino mice. Supplementation of CoQ10 abrogates these deleterious effects of aroclor 1254. CoQ10 also apparently enhanced acetyl cholinesterase activity which reflects its influence on the cholinergic system.

  1. Contamination of freshwater fish from rivers Sava and Danube with polychlorinated biphenyls

    International Nuclear Information System (INIS)

    Jankovic, S.; Radicevic, T.; Spiric, A.; Nedeljkovic, M.

    2002-01-01

    During air strikes, in april 1999, Institute of meat hygiene and technology have begun examination of freshwater fish to establish the degree of contamination. The information about damaged industrial facilities and toxic waste that have been spilled were hard to find, and was unofficial and contradicts. Because of that, at the first time we collected samples from different locations, but after first results, we concentrated our attention on locations on river Danube downstream from Pancevo and on river Sava upstream from Belgrade, the locations indicated as environmental 'hot spots'. According to our experience, knowledge, equipment and analytical skills we have chosen to determine the concentrations of PCBs in freshwater fish species, since aquatic fauna might be used as indicator organisms for the evaluation of water pollution. Polychlorinated biphenyls as contaminant of interest, have been chosen because large quantities of PCBs reached the soil and waste and ground waters from damaged transformers and capacitors, where they serve as dielectric fluids. Also, PCBs are highly toxic and due to their liposolubility and persistence, these compounds accumulate through food chain. In 1999, from April to December, we had collected 23 samples of different fish species on river Danube, downstream from Pancevo and 15 samples from locations on river Sava upstream from Belgrade. The concentrations of PCBs (mg/kg fat and mg/kg fresh weight) were expressed as the sum of individual congeners (IUPAC numbers 28, 52, 101, 138, 153, 180) and as Aroclor 1260 (peaks were identified as a fingerprint pattern by comparison with Aroclor standards). The concentrations of PCBs (mg/kg fat) are determined to evaluate the extent of contamination and concentrations of PCBs (mg/kg fresh weight) indicate daily intake and help us to estimate the risk for human health. Residues of PCBs in the fat extracted from fish sample were analysed according to the USDA Analytical Chemistry Guidebook. Gas

  2. Thermic decomposition of biphenyl; Decomposition thermique du biphenyle

    Energy Technology Data Exchange (ETDEWEB)

    Lutz, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1966-03-01

    Liquid and vapour phase pyrolysis of very pure biphenyl obtained by methods described in the text was carried out at 400 C in sealed ampoules, the fraction transformed being always less than 0.1 per cent. The main products were hydrogen, benzene, terphenyls, and a deposit of polyphenyls strongly adhering to the walls. Small quantities of the lower aliphatic hydrocarbons were also found. The variation of the yields of these products with a) the pyrolysis time, b) the state (gas or liquid) of the biphenyl, and c) the pressure of the vapour was measured. Varying the area and nature of the walls showed that in the absence of a liquid phase, the pyrolytic decomposition takes place in the adsorbed layer, and that metallic walls promote the reaction more actively than do those of glass (pyrex or silica). A mechanism is proposed to explain the results pertaining to this decomposition in the adsorbed phase. The adsorption seems to obey a Langmuir isotherm, and the chemical act which determines the overall rate of decomposition is unimolecular. (author) [French] Du biphenyle tres pur, dont la purification est decrite, est pyrolyse a 400 C en phase vapeur et en phase liquide dans des ampoules scellees sous vide, a des taux de decomposition n'ayant jamais depasse 0,1 pour cent. Les produits provenant de la pyrolyse sont essentiellement: l' hydrogene, le benzene, les therphenyles, et un depot de polyphenyles adherant fortement aux parois. En plus il se forme de faibles quantites d'hydrocarbures aliphatiques gazeux. On indique la variation des rendements des differents produits avec la duree de pyrolyse, l'etat gazeux ou liquide du biphenyle, et la pression de la vapeur. Variant la superficie et la nature des parois, on montre qu'en absence de liquide la pyrolyse se fait en phase adsorbee. La pyrolyse est plus active au contact de parois metalliques que de celles de verres (pyrex ou silice). A partir des resultats experimentaux un mecanisme de degradation du biphenyle en phase

  3. Thermal decomposition of biphenyl (1963); Decomposition thermique du biphenyle (1963)

    Energy Technology Data Exchange (ETDEWEB)

    Clerc, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1962-06-15

    The rates of formation of the decomposition products of biphenyl; hydrogen, methane, ethane, ethylene, as well as triphenyl have been measured in the vapour and liquid phases at 460 deg. C. The study of the decomposition products of biphenyl at different temperatures between 400 and 460 deg. C has provided values of the activation energies of the reactions yielding the main products of pyrolysis in the vapour phase. Product and Activation energy: Hydrogen 73 {+-} 2 kCal/Mole; Benzene 76 {+-} 2 kCal/Mole; Meta-triphenyl 53 {+-} 2 kCal/Mole; Biphenyl decomposition 64 {+-} 2 kCal/Mole; The rate of disappearance of biphenyl is only very approximately first order. These results show the major role played at the start of the decomposition by organic impurities which are not detectable by conventional physico-chemical analysis methods and the presence of which accelerates noticeably the decomposition rate. It was possible to eliminate these impurities by zone-melting carried out until the initial gradient of the formation curves for the products became constant. The composition of the high-molecular weight products (over 250) was deduced from the mean molecular weight and the dosage of the aromatic C - H bonds by infrared spectrophotometry. As a result the existence in tars of hydrogenated tetra, penta and hexaphenyl has been demonstrated. (author) [French] Les vitesses de formation des produits de decomposition du biphenyle: hydrogene, methane, ethane, ethylene, ainsi que des triphenyles, ont ete mesurees en phase vapeur et en phase liquide a 460 deg. C. L'etude des produits de decomposition du biphenyle a differentes temperatures comprises entre 400 et 460 deg. C, a fourni les valeurs des energies d'activation des reactions conduisant aux principaux produits de la pyrolyse en phase vapeur. Produit et Energie d'activation: Hydrogene 73 {+-} 2 kcal/Mole; Benzene 76 {+-} 2 kcal/Mole; Metatriphenyle, 53 {+-} 2 kcal/Mole; Decomposition du biphenyle 64 {+-} 2 kcal/Mole; La

  4. CHANGES IN PROTEOMIC PROFILES OF CEREBELLUM FOLLOWING DEVELOPMENTAL EXPOSURE TO AROCLOR 1254 OR DE-71.

    Science.gov (United States)

    Chronic low level exposure to polychlorinated biphenyls (PCBs) has been shown to adversely affect human health, including learning and memory. Polybromiated diphenyl ethers (PBDEs) are structurally similar to PCBs and have been shown to have neurotoxic effects in vitro and in viv...

  5. Reductive Dechlorination of Polychlorinated Biphenyls in Marine Sediments

    National Research Council Canada - National Science Library

    Sowers, Kevin

    1999-01-01

    ... Community by Comparative Sequence Analysis of Genes Coding for 16S rRNA, Microbial Reductive Dechlorination of Aroclor 1260 in Anaerobic Slurries of Estuarine Sediments, Differential RFLP patterns of PCR...

  6. Defining the sources of airborne polychlorinated biphenyls: evidence for the influence of microbially dechlorinated congeners from river sediment?

    Energy Technology Data Exchange (ETDEWEB)

    Chiarenzelli, J. [SUNYat Oswego, NY (United States); Bush, B.; Casey, A.; O' Keefe, P. [SUNY at Albany, School of Public Health, Rensselaer, NY (United States); Barnard, E.; Smith, B. [New York State Dept. of Health, Wadsworth Center for Laboratories and Research, Albany, NY (United States); Gilligan, E. [Syracuse Univ., Dept. of Civil an Environmental Engineering, NY (United States); Johnson, G. [Energy and Geoscience Institute, Dept, of Civil and Environmental Engineering, Salt Lake City, UT (United States)

    2000-07-01

    During sampling in 1993, elevated levels of polychlorinated biphenyls were discovered near three industrial facilities on the Akwesasne Mohawk Nation Reserve along the St. Lawrence River, straddling the Canadian-US. border. Volatilization of Aroclor 1248, which was used extensively at all three sites, was identified as the dominant source, augmented in a minor way by a dechlorinated source, presumably from river sediment and waters. These two sources were found to account for 80 per cent of the contamination. Further, it was established that at a small cove adjacent to an industrial landfill, summer concentrations of PCBs exceeded winter concentrations by a factor of 27. Observation showed the presence of similar congener-specific PCB patterns at all sample sites and an increase in the concentrations of chlorine to biphenyl ratios during the summer months. During the colder months PCB concentrations at all sites declined, nevertheless, PCB levels were still higher than those measured elsewhere in the Great Lakes region during the same time period. Results of this investigation suggest that atmospheric deposition from local contaminant sources can elevate concentrations in produce and vegetative matter, complicating exposure routes and bioaccumulation via modeling of food chain. 22 refs., 4 tabs. 1 fig.

  7. New technologies for PCB [polychlorinated biphenyl] decontamination

    International Nuclear Information System (INIS)

    Webber, I.

    1993-01-01

    Polychlorinated biphenyls (PCB) were mixed with chlorobenzenes to reduce viscosity and provide for both electrical insulation and convective heat transfers. These mixtures were known as askarels, and ca 99.8% of PCBs used in electrical applications are contained in askarel-filled transformers and capacitors. It is estimated that there are ca 180 million gal of PCB-contaminated oil distributed through over 3 million transformers in the USA. Technology used for decontaminating these transformers depends on the concentration of the PCB contamination. At low PCB concentrations of up to ca 2,000 ppM, chemical methods can be used; at higher concentrations, alternative disposal options become more attractive. For chemical treatment, a small mobile unit using quick-reacting reagents has been developed for on-site decontamination. For highly contaminated transformers, retrofilling is very attractive since the owner's liability is minimized at minimum cost. Conventional flush/drain procedures have such drawbacks as the inability to remove oil trapped in windings and the leaching of trapped PCBs back into the uncontaminated retrofill oil over time. A new process has been developed to solve the leaching problem and to decontaminate the drained askarel at room temperature using a catalyst. An alternative disposal strategy involves dismantling the transformer carcass, incinerating non-recyclable materials, and cleaning the metals and wire with solvent. 8 figs

  8. Individual Polychlorinated Biphenyl (PCB) Congeners Produce Tissue- and Gene-Specific Effects on Thyroid Hormone Signaling during Development

    Science.gov (United States)

    Giera, Stefanie; Bansal, Ruby; Ortiz-Toro, Theresa M.; Taub, Daniel G.

    2011-01-01

    Polychlorinated biphenyls (PCB) are industrial chemicals linked to developmental deficits that may be caused in part by disrupting thyroid hormone (TH) action by either reducing serum TH or interacting directly with the TH receptor (TR). Individual PCB congeners can activate the TR in vitro when the metabolic enzyme cytochrome P4501A1 (CYP1A1) is induced, suggesting that specific PCB metabolites act as TR agonists. To test this hypothesis in vivo, we compared two combinations of PCB congeners that either activate the TR (PCB 105 and 118) or not (PCB 138 and 153) in the presence or absence of a PCB congener (PCB 126) that induces CYP1A1 in vitro. Aroclor 1254 was used as a positive control, and a group treated with propylthiouracil was included to characterize the effects of low serum TH. We monitored the effects on TH signaling in several peripheral tissues by measuring the mRNA expression of well-known TH-response genes in these tissues. Aroclor 1254 and its component PCB 105/118/126 reduced total T4 to the same extent as that of propylthiouracil but increased the expression of some TH target genes in liver. This effect was strongly correlated with CYP1A1 expression supporting the hypothesis that metabolism is necessary. Effects were gene and tissue specific, indicating that tissue-specific metabolism is an important component of PCB disruption of TH action and that PCB metabolites interact in complex ways with the TR. These are essential mechanisms to consider when evaluating the health risks of contaminant exposures, for both PCB and other polycyclic compounds known to interact with nuclear hormone receptors. PMID:21540284

  9. Phytoalexins of the Pyrinae: Biphenyls and dibenzofurans

    Directory of Open Access Journals (Sweden)

    Cornelia Chizzali

    2012-04-01

    Full Text Available Biphenyls and dibenzofurans are the phytoalexins of the Pyrinae, a subtribe of the plant family Rosaceae. The Pyrinae correspond to the long-recognized Maloideae. Economically valuable species of the Pyrinae are apples and pears. Biphenyls and dibenzofurans are formed de novo in response to infection by bacterial and fungal pathogens. The inducible defense compounds were also produced in cell suspension cultures after treatment with biotic and abiotic elicitors. The antimicrobial activity of the phytoalexins was demonstrated. To date, 10 biphenyls and 17 dibenzofurans were isolated from 14 of the 30 Pyrinae genera. The most widely distributed compounds are the biphenyl aucuparin and the dibenzofuran γ-cotonefuran. The biosynthesis of the two classes of defense compounds is not well understood, despite the importance of the fruit crops. More recent studies have revealed simultaneous accumulation of biphenyls and dibenzofurans, suggesting sequential, rather than the previously proposed parallel, biosynthetic pathways. Elicitor-treated cell cultures of Sorbus aucuparia served as a model system for studying phytoalexin metabolism. The key enzyme that forms the carbon skeleton is biphenyl synthase. The starter substrate for this type-III polyketide synthase is benzoyl-CoA. In apples, biphenyl synthase is encoded by a gene family, members of which are differentially regulated. Metabolism of the phytoalexins may provide new tools for designing disease control strategies for fruit trees of the Pyrinae subtribe.

  10. Polychlorinated biphenyls in honey bees

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Laboratory evaluation of polychlorinated biphenyls ...

    Science.gov (United States)

    Effectiveness and limitations of the encapsulation method for reducing polychlorinated biphenyls (PCBs) concentrations in indoor air and contaminated surface have been evaluated in the laboratory study. Ten coating materials such as epoxy and polyurethane coatings, latex paint, and petroleum-based paint were tested in small environmental chambers to rank the encapsulants by their resistance to PCB sorption and estimate the key parameters required by a barrier model. Wipe samples were collected from PCB contaminated surface encapsulated with the coating materials to rank the encapsulants by their resistance to PCB migration from the source. A barrier model was used to calculate the PCB concentrations in the sources and the encapsulant layers, and at the exposed surfaces of the encapsulant and in the room air at different times. The performance of the encapsulants was ranked by those concentrations and PCB percent reductions. Overall, the three epoxy coatings performed better than the other coatings. Both the experimental results and the mathematical modeling showed that selecting proper encapsulants can effectively reduce the PCB concentrations at the exposed surfaces. The encapsulation method is most effective for contaminated surfaces that contain low levels of PCBs. This study answers some of these questions by using a combination of laboratory testing and mathematical modeling. The results should be useful to mitigation engineers, building owners and managers

  12. Microbial transformation and degradation of polychlorinated biphenyls

    Energy Technology Data Exchange (ETDEWEB)

    Field, Jim A. [Department of Chemical and Environmental Engineering, University of Arizona, PO Box 210011, Tucson, AZ 85721 (United States)], E-mail: jimfield@email.arizona.edu; Sierra-Alvarez, Reyes [Department of Chemical and Environmental Engineering, University of Arizona, PO Box 210011, Tucson, AZ 85721 (United States)

    2008-09-15

    This paper reviews the potential of microorganisms to transform polychlorinated biphenyls (PCBs). In anaerobic environments, higher chlorinated biphenyls can undergo reductive dehalogenation. Meta- and para-chlorines in PCB congeners are more susceptible to dechlorination than ortho-chlorines. Anaerobes catalyzing PCB dechlorination have not been isolated in pure culture but there is strong evidence from enrichment cultures that some Dehalococcoides spp. and other microorganisms within the Chloroflexi phylum can grow by linking the oxidation of H{sub 2} to the reductive dechlorination of PCBs. Lower chlorinated biphenyls can be co-metabolized aerobically. Some aerobes can also grow by utilizing PCB congeners containing only one or two chlorines as sole carbon/energy source. An example is the growth of Burkholderia cepacia by transformation of 4-chlorobiphenyl to chlorobenzoates. The latter compounds are susceptible to aerobic mineralization. Higher chlorinated biphenyls therefore are potentially fully biodegradable in a sequence of reductive dechlorination followed by aerobic mineralization of the lower chlorinated products. - Higher chlorinated biphenyls are potentially fully biodegradable in a sequence of anaerobic reductive dechlorination followed by aerobic mineralization of the lower chlorinated products.

  13. Microbial transformation and degradation of polychlorinated biphenyls

    International Nuclear Information System (INIS)

    Field, Jim A.; Sierra-Alvarez, Reyes

    2008-01-01

    This paper reviews the potential of microorganisms to transform polychlorinated biphenyls (PCBs). In anaerobic environments, higher chlorinated biphenyls can undergo reductive dehalogenation. Meta- and para-chlorines in PCB congeners are more susceptible to dechlorination than ortho-chlorines. Anaerobes catalyzing PCB dechlorination have not been isolated in pure culture but there is strong evidence from enrichment cultures that some Dehalococcoides spp. and other microorganisms within the Chloroflexi phylum can grow by linking the oxidation of H 2 to the reductive dechlorination of PCBs. Lower chlorinated biphenyls can be co-metabolized aerobically. Some aerobes can also grow by utilizing PCB congeners containing only one or two chlorines as sole carbon/energy source. An example is the growth of Burkholderia cepacia by transformation of 4-chlorobiphenyl to chlorobenzoates. The latter compounds are susceptible to aerobic mineralization. Higher chlorinated biphenyls therefore are potentially fully biodegradable in a sequence of reductive dechlorination followed by aerobic mineralization of the lower chlorinated products. - Higher chlorinated biphenyls are potentially fully biodegradable in a sequence of anaerobic reductive dechlorination followed by aerobic mineralization of the lower chlorinated products

  14. 21 CFR 109.30 - Tolerances for polychlorinated biphenyls (PCB's).

    Science.gov (United States)

    2010-04-01

    ... Tolerances for polychlorinated biphenyls (PCB's). (a) Polychlorinated biphenyls (PCB's) are toxic, industrial chemicals. Because of their widespread, uncontrolled industrial applications, PCB's have become a persistent... unavoidable environmental or industrial contaminants are established for a sufficient period of time following...

  15. Application of tritium-labeled complex technical mixture of PCB congeners as radiotracer in ecological investigations

    International Nuclear Information System (INIS)

    Kim, A.A.

    2005-01-01

    The quantitative analysis of PCBs (polychlorinated biphenyls) is enough difficult analytical task. According to IUPAC nomenclature it is described more than 200 possible PCB congeners from which about 150 congeners are present at an environment. At the same time in environment PCBs are present as complex technical mixes of congeners (trade names include Apirolio, Aroclor, Clophen, Fenchlor, Kanechlor, Phenoclor, Pyralene, Pyranol, Pyroclor, Santotherm FR, and Sovol). In routine practice of gas chromatography analysis the quantitative measurement of PCB marker congeners is applied. In the most samples containing PCBs, there are often several dozens of different congeners. For practical reasons, all of them are not always measured, but the most important congeners are used as indicators. In Belgian chicken incident, only seven abundant congeners were usually measured: congeners with IUPAC numbers 28, 52, 101, 118, 138, 153, and 180 (2,4,4 '-TriCB, 2,2 ', 5,5 '-TCB, 2,2 ', 4,5,5 '-PeCB, 2,3 ', 4,4 ', 5-PeCB, 2,2 ', 3,4,4 ', 5 '-HxCB, 2,2 ', 4,4 ', 5,5 '-HxCB, 2,2 ', 3,4,4 ', 5,5 '-HpCB, respectively). The seven congeners are estimated to constitute about one third of all PCBs in the contaminated feed. Such measurement can give the big error in a quantitative estimation of PCBs contents in a sample. As alternative method of quantitative measurement PCBs the radiochemical method with use radioactive labeled PCBs as radiotracer can be used. We had been developed a method of synthesis of labeled by thermally activated tritium a complex technical mixture of PCBs congeners - Sovol. We had been showed a basic opportunity of receiving of uniformly tritium labeled mixture of PCBs congeners without structural failure of mixture. The tritium labeled preparation of complex technical mixture of PCBs congeners (Sovol) has been received. On the basis of received tritium labeled preparation of PCBs (Sovol) we had been developed the following quantitative and qualitative radiochemical

  16. Accumulation of polychlorinated biphenyls (PCBs) and evaluation of hematological and immunological effects of PCB exposure on turtles.

    Science.gov (United States)

    Yu, Shuangying; Halbrook, Richard S; Sparling, Donald W

    2012-06-01

    Concentrations of total polychlorinated biphenyls (PCBs), Aroclor 1260, and 26 congeners were measured in liver, fat, and eggs of red-eared slider turtles (Trachemys scripta elegans) collected from ponds near or on the Paducah Gaseous Diffusion Plant (PGDP), Kentucky, USA. Concentrations of total PCBs (wet mass) ranged from 0.002 to 0.480 mg/kg, 0.028 to 0.839 mg/kg, and 0.001 to 0.011 mg/kg in liver, fat, and eggs, respectively. Concentrations of Arochlor 1260 did not exceed 0.430, 0.419, and 0.007 mg/kg in liver, fat, and eggs, respectively. Exposure to PCBs in red-eared sliders collected from the PGDP is characterized by low concentrations of moderately chlorinated mono-ortho and di-ortho congeners (PCB 153, 180, and 118). Although PCB concentrations measured in the current study were low, chronic exposure to PCBs may have altered hematology and immunity of the turtles examined. Total white blood cell count and number of heterophils were negatively correlated with concentrations of total PCBs and Arochlor 1260, respectively. However, disease and other contaminants in the study area may influence the results. Because little is known regarding the influence of PCBs on hematology and immune function in turtles, additional study is needed to better evaluate results observed in the current study.

  17. Sources, emissions, and fate of polybrominated diphenyl ethers and polychlorinated biphenyls indoors in Toronto, Canada.

    Science.gov (United States)

    Zhang, Xianming; Diamond, Miriam L; Robson, Matthew; Harrad, Stuart

    2011-04-15

    Indoor air concentrations of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) measured in 20 locations in Toronto ranged 0.008-16 ng·m(-3) (median 0.071 ng·m(-3)) and 0.8-130.5 ng·m(-3) (median 8.5 ng·m(-3)), respectively. PBDE and PCB air concentrations in homes tended to be lower than that in offices. Principal component analysis of congener profiles suggested that electrical equipment was the main source of PBDEs in locations with higher concentrations, whereas PUF furniture and carpets were likely sources to locations with lower concentrations. PCB profiles in indoor air were similar to Aroclors 1248, 1232, and 1242 and some exterior building sealant profiles. Individual PBDE and PCB congener concentrations in air were positively correlated with colocated dust concentrations, but total PBDE and total PCB concentrations in these two media were not correlated. Equilibrium partitioning between air and dust was further examined using log-transformed dust/air concentration ratios for which lower brominated PBDEs and all PCBs were correlated with K(OA). This was not the case for higher brominated BDEs for which the measured ratios fell below those based on K(OA) suggesting the air-dust partitioning process could be kinetically limited. Total emissions of PBDEs and PCBs to one intensively studied office were estimated at 87-550 ng·h(-1) and 280-5870 ng·h(-1), respectively, using the Multimedia Indoor Model of Zhang et al. Depending on the air exchange rate, up to 90% of total losses from the office could be to outdoors by means of ventilation. These results support the hypotheses that dominant sources of PBDEs differ according to location and that indoor concentrations and hence emissions contribute to outdoor concentrations due to higher indoor than outdoor concentrations along with estimates of losses via ventilation.

  18. Effects of subacute PVB-exposure (Arocolor 1254) on oxygen consumption, swimming behavior and biotransformation (GST-activity) of carp (Cyprinus carpio); Wirkung subakuter PCB-Exposition (Aroclor 1254) auf Sauerstoffverbrauch, Schwimmbewegung und Biotransformation (GST-Aktivitaet) des Karpfens (Cyprinus carpio)

    Energy Technology Data Exchange (ETDEWEB)

    Pflugmacher, S.; Staaks, G.B.O.; Steinberg, C.E.W. [Leibniz Inst. fuer Gewaesseroekologie und Binnenfischerei, Berlin (Germany); Schmidt, K.

    2005-07-01

    Objective and Background. PCB (polychlorinated biphenyle) are typical man-made environmental pollutants that cause a broad spectrum of effects in vertebrates. Although a lot has been studied about the toxic effects of xenobiotic substances on aquatic organisms, their subacute effects are not yet well known. Fish occupies a central position in freshwater food webs and therefore, carp was chosen to be our test organism. The aim of our study was the investigation of subacute effects of Aroclor 1254 (22 {mu}g l{sup -1}) on respiration, swimming activity, and biotransformation, allowing discussion of changed interaction between the available energy resources. Methods. The respiration experiments under controlled laboratory conditions were run for 29 days (5 d before, 16 d with and 8 d after chemical exposure) with exposed carp compared to the non-exposed fish. Furthermore, the BehavioQuant system quantitatively monitors the positions of each individual fish before (8 d) and during (21 d) PCB exposure and swimming activity (number of horizontal turnings s{sup -1}) of animals was calculated. Thereafter, liver samples were taken from animals for analysis of the phase 2 enzyme activity (glutathione-S-transferase). In the respiration experiments were 6 exposure, 6 control, and 3 solubilizer control groups (12 animals each group); in the behavioral experiments were 9 exposure, 6 control- and 3 solubilizer control groups (6 animals each group), and in the enzyme activity measurements were 9 exposure, 6 control and 3 solubilizer control groups (6 animals each group) examined. (orig.)

  19. Plant enzymes in metabolism of polychlorinated biphenyls

    Czech Academy of Sciences Publication Activity Database

    Chromá, L.; Moeder, M.; Kučerová, P.; Macek, Tomáš; Macková, M.

    2003-01-01

    Roč. 12, č. 3 (2003), s. 291-295 ISSN 1018-4619 R&D Projects: GA MŠk ME 498 Institutional research plan: CEZ:AV0Z4055905 Keywords : polychlorinated biphenyls * plants * peroxidases Subject RIV: CE - Biochemistry Impact factor: 0.325, year: 2003

  20. Updated Abraham solvation parameters for polychlorinated biphenyls

    NARCIS (Netherlands)

    van Noort, P.C.M.; Haftka, J.J.H.; Parsons, J.R.

    2010-01-01

    This study shows that the recently published polychlorinated biphenyl (PCB) Abraham solvation parameters predict PCB air−n-hexadecane and n-octanol−water partition coefficients very poorly, especially for highly ortho-chlorinated congeners. Therefore, an updated set of PCB solvation parameters was

  1. Updated Abraham solvation parameters for polychlorinated biphenyls

    NARCIS (Netherlands)

    Noort, van P.C.M.; Haftka, J.J.H.; Parsons, J.R.

    2010-01-01

    This study shows that the recently published polychlorinated biphenyl (PCB) Abraham solvation parameters predict PCB air-n-hexadecane and n-octanol-water partition coefficients very poorly, especially for highly ortho-chlorinated congeners. Therefore, an updated set of PCB solvation parameters was

  2. Bioaccumulation of polychlorinated biphenyls and organochlorine pesticides in young-of-the-year bluefish (Pomatomus saltatrix) in the vicinity of a Superfund Site in New Bedford Harbor, Massachusetts, and in the adjacent waters.

    Science.gov (United States)

    Deshpande, Ashok D; Dockum, Bruce W; Cleary, Thomas; Farrington, Cameron; Wieczorek, Daniel

    2013-07-15

    Spatial gradients of polychlorinated biphenyls (PCBs) and organochlorine pesticides were examined in the young-of-the-year (YOY) bluefish (Pomatomus saltatrix) in the vicinity of a PCB Superfund Site in New Bedford Harbor, Massachusetts, and in the adjacent waters. PCB concentrations in bluefish varied between different locations, and also among fish from a given location. A generally decreasing gradient in PCB concentrations was evident as the bluefish were collected away from the Superfund Site. The average sum of PCB concentrations were highest for bluefish collected in the Upper Harbor between Interstate-195 Bridge and Coggeshall Street Bridge (Upper Harbor), followed by bluefish in Lower Harbor from north of Popes Island Bridge (Lower Harbor), and bluefish from Outer Harbor south of Hurricane Barrier (Outer Harbor). The levels of PCBs in bluefish from Clarks Cove and PCBs in bluefish from Buzzards Bay were similar and lowest among all bluefish specimens analyzed in the present study. Pesticide concentrations were about one order of magnitude or lower than the PCB concentrations, and the gradient of pesticide concentrations generally followed the gradient of PCB concentrations. Some of the commonly detected pesticides in the order of decreasing concentrations included DDTs and metabolites, heptachlor epoxide, endosulfan sulfate, and α-chlordane. Distribution of PCBs and organochlorine pesticides were examined in the tissues of YOY bluefish from Clarks Cove. PCBs and lipids in the brain samples of YOY bluefish were generally numerically greater than PCBs in the liver samples, but these differences were not statistically significant. PCBs and lipids in hypaxial muscle samples were numerically greater than PCBs in epaxial muscle samples, although these two groups of tissues were not statistically different. Despite the higher susceptibility of lighter PCB homologs to geophysical and biogeochemical weathering processes, the relative dominance of lighter homologs

  3. Alteration of General Behavior of Male Medaka,oryzias latipes,Exposed to Tributyltin and /or Polychlorinated Biphenyls

    OpenAIRE

    Nakayama, Kei; Oshima, Yuji; Hiramatsu, Kazuaki; Honjo, Tsuneo

    2004-01-01

    We examined the general behavior of male Japanese medaka, Oryzias latipes, after exposed to tributyltin (TBT), polychlorinated biphenyls (PCBs), or a mixture of these chamicals at a concentration of 1μg/g body weight daily for 3 weeks. We analyzed swimming velocity as an indicator of acute toxicity and counted the frequencies of straight swimming and swimming in circles. We also calclated the entropy of the positions of the fish within the experimental chamber. Neither TBT nor PCBs nor their ...

  4. Exposure Monitoring and Risk Assessment of Biphenyl in the Workplace

    OpenAIRE

    Kim, Hyeon-Yeong; Shin, Sae-Mi; Ham, Miran; Lim, Cheol-Hong; Byeon, Sang-Hoon

    2015-01-01

    This study was performed to assess exposure to and the risk caused by biphenyl in the workplace. Biphenyl is widely used as a heat transfer medium and as an emulsifier and polish in industry. Vapor or high levels of dust inhalation and dermal exposure to biphenyl can cause eye inflammation, irritation of respiratory organs, and permanent lesions in the liver and nervous system. In this study, the workplace environment concentrations were assessed as central tendency exposure and reasonable ma...

  5. Remediation of PCB [polychlorinated biphenyl] -contaminated soils from scrapyards

    International Nuclear Information System (INIS)

    MacKnight, S.

    1991-01-01

    Much of the recent attention on contamination of the environment by polychlorinated biphenyls (PCB) has focused on liquid PCB spills from electrical equipment. A new, and possibly more serious, source of PCB contamination is the scrap yard, typically located in or near major urban centers, where the local scrap dealer would purchase used transformers or other PCB-containing electrical equipment, recover copper and other metals, and dump the PCB-containing oils on the ground. With the rising value of urban and suburban lands, these scrap yards may be slated for redevelopment, making the cleanup of contaminated soils necessary. The heterogeneous distribution of scrap yard contaminants requires a very detailed site assessment, and the heterogeneous mixture of typical scrap yard contaminants (not only PCB) cannot be treated in a simple fashion. These problems are illustrated for the case of the assessment and cleanup of a scrap yard site in Nova Scotia. A grid block system was used to sample soil at the site, and samples were analyzed for PCB, metals, and hydrocarbons. The most severely contaminated spots were mapped; groundwater patterns were also examined. The remediation process can be divided into 5 phases: physical separation of uncontaminated material; three stages of separation of materials into those having single, several-but-similar, and multicomponent mixed contaminations; and selection of appropriate process technologies. Since there is currently no approved PCB destruction facility in Atlantic Canada, excavated soils containing PCB are stored securely on the site to await approval for some type of incineration process

  6. Can polychlorinated biphenyl (PCB) signatures and enantiomer fractions be used for source identification and to age date occupational exposure?

    Science.gov (United States)

    Megson, David; Focant, Jean-Françios; Patterson, Donald G; Robson, Matthew; Lohan, Maeve C; Worsfold, Paul J; Comber, Sean; Kalin, Robert; Reiner, Eric; O'Sullivan, Gwen

    2015-08-01

    Detailed polychlorinated biphenyl (PCB) signatures and chiral Enantiomer Fractions (EFs) of CB-95, CB-136 and CB-149 were measured for 30 workers at a transformer dismantling plant. This was undertaken to identify sources of exposure and investigate changes to the PCB signature and EFs over different exposure periods. Approximately 1.5 g of serum was extracted and PCB signatures were created through analysis by comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC×GC-TOFMS) and EFs calculated following analysis by gas chromatography with high resolution mass spectrometry (GC-HRMS). A total of 84 PCBs were identified in the serum samples with concentrations of the 7 indicator PCBs ranging from 11-350 ng g(-1) of serum (1.2-39 μg g(-1) lipid). The PCB signatures were interpreted using principal component analysis (PCA) which was able to distinguish workers with background or recent minimal exposure from those with prolonged occupational exposure. Occupationally exposed individuals had a similar PCB profile to Aroclor A1260. However, individuals with prolonged exposure had depleted proportions of several PCB congeners that are susceptible to metabolism (CB-95, CB-101 and CB-151) and elevated proportions of PCBs that are resistant to metabolism (CB-74, CB-153, CB-138 and CB-180). The results also identified a third group of workers with elevated proportions of CB-28, CB-60, CB-66, CB-74, CB-105 and CB-118 who appeared to have been exposed to an additional source of PCBs. The results show near complete removal of the CB-95 E2 enantiomer in some samples, indicating that bioselective metabolism or preferential excretion of one enantiomer occurs in humans. By considering PCB concentrations along with detailed congener specific signatures it was possible to identify different exposure sources, and gain an insight into both the magnitude and duration of exposure. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. CHANGES IN NUCLEAR TRANSCRIPTION FACTORS IN RAT HIPPOCAMPUS AND CEREBELLUM FOLLOWING DEVELOPMENTAL EXPOSURE TO A COMMERCIAL PCB MIXTURE.

    Science.gov (United States)

    Polychlorinated biphenyls (PCBs) offer a unique model to understand the major issues related to complex environmental mixtures. These pollutants are ubiquitous and exist as mixtures of several congeners in the environment. Human exposures to PCBs are associated with a variety of ...

  8. Grouting mixture

    Energy Technology Data Exchange (ETDEWEB)

    Klyusov, A A; Bakshutov, V S; Kulyavtsev, V A

    1980-10-23

    A grouting mixture is proposed for low-temperature boreholes. The mixture contains cement, beta gypsum polyhydrate, and calcium chloride, so as to increase the water resistance and strength properties of expanding brick at conditions from 20 to -5/sup 0/ C, the components are in the following ratios: (by wt.-%): cement, 77.45-88.06; beta gypsum polyhydrate, 9.79-19.36; calcium chloride, 2.15-3.19. Grouting mortar for cold boreholes serves as the cement.

  9. Draft Genome Sequence of Cupriavidus pauculus Strain KF709, a Biphenyl-Utilizing Bacterium Isolated from Biphenyl-Contaminated Soil.

    Science.gov (United States)

    Watanabe, Takahito; Yamazoe, Atsushi; Hosoyama, Akira; Fujihara, Hidehiko; Suenaga, Hikaru; Hirose, Jun; Futagami, Taiki; Goto, Masatoshi; Kimura, Nobutada; Furukawa, Kensuke

    2015-03-26

    We report the draft genome sequence of Cupriavidus pauculus strain KF709, which comprises 6,826,799 bp with 6,272 coding sequences. The strain KF709 utilizes biphenyl and degrades low-chlorinated biphenyls; however, it possesses fewer coding sequences involved in the degradation of aromatic compounds than other strains belonging to the Betaproteobacteria. Copyright © 2015 Watanabe et al.

  10. Draft Genome Sequence of Cupriavidus pauculus Strain KF709, a Biphenyl-Utilizing Bacterium Isolated from Biphenyl-Contaminated Soil

    OpenAIRE

    Watanabe, Takahito; Yamazoe, Atsushi; Hosoyama, Akira; Fujihara, Hidehiko; Suenaga, Hikaru; Hirose, Jun; Futagami, Taiki; Goto, Masatoshi; Kimura, Nobutada; Furukawa, Kensuke

    2015-01-01

    We report the draft genome sequence of Cupriavidus pauculus strain KF709, which comprises 6,826,799 bp with 6,272 coding sequences. The strain KF709 utilizes biphenyl and degrades low-chlorinated biphenyls; however, it possesses fewer coding sequences involved in the degradation of aromatic compounds than other strains belonging to the Betaproteobacteria.

  11. Process for removing polychlorinated biphenyls from soil

    Science.gov (United States)

    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.

  12. Radionuclides, Heavy Metals, and Polychlorinated Biphenyls in Soils Collected Around the Perimeter of Low-Level Radioactive Waste Disposal Area G during 2006

    International Nuclear Information System (INIS)

    P. R. Fresquez

    2007-01-01

    Twenty-one soil surface samples were collected in March around the perimeter of Area G, the primary disposal facility for low-level radioactive solid waste at Los Alamos National Laboratory (LANL). Three more samples were collected in October around the northwest corner after elevated tritium levels were detected on an AIRNET station located north of pit 38 in May. Also, four soil samples were collected along a transect at various distances (48, 154, 244, and 282 m) from Area G, starting from the northeast corner and extending to the Pueblo de San Ildefonso fence line in a northeasterly direction (this is the main wind direction). Most samples were analyzed for radionuclides ( 3 H, 238 Pu, 239,240 Pu, 241 Am, 234 U, 235 U, and 238 U), inorganic elements (Al, Ba, Be, Ca, Cr, Co, Cu, Fe, Mg, Mn, Ni, K, Na, V, Hg, Zn, Sb, As, Cd, Pb, Se, Ag, and Tl) and polychlorinated biphenyl (PCB) concentrations. As in previous years, the highest levels of 3 H in soils (690 pCi/mL) were detected along the south portion of Area G near the 3 H shafts; whereas, the highest concentrations of 241 Am (1.2 pCi/g dry) and the Pu isotopes (1.9 pCi/g dry for 238 Pu and 5 pCi/g dry for 239,240 Pu) were detected along the northeastern portions near the transuranic waste pads. Concentrations of 3 H in three soil samples and 241 Am and Pu isotopes in one soil sample collected around the northwest corner in October increased over concentrations found in soils collected at the same locations earlier in the year. Almost all of the heavy metals, with the exception of Zn and Sb in one sample each, in soils around the perimeter of Area G were below regional statistical reference levels (mean plus three standard deviations) (RSRLs). Similarly, only one soil sample collected on the west side contained PCB concentrations--67 (micro)g/kg dry of aroclor-1254 and 94 (micro)g/kg dry of aroclor-1260. Radionuclide and inorganic element concentrations in soils collected along a transect from Area G to the

  13. Spatial gradients of polychlorinated biphenyls (PCBs) and organochlorine pesticides

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Spatial gradients of polychlorinated biphenyls (PCBs) and organochlorine pesticides were examined in the young-of-the-year (YOY) blueÂżsh collected in the vicinity...

  14. Bioaccumulation dynamics of polychlorinated biphenyls (PCBs) and organochlorine pesticides

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bioaccumulation dynamics of polychlorinated biphenyls (PCBs) and organochlorine pesticides was examined in young-of-the-year bluefish from seven sub-estuaries of New...

  15. NUCLEOTIDE SEQUENCING AND TRANSCRIPTIONAL MAPPING OF THE GENES ENCODING BIPHENYL DIOXYGENASE, A MULTICOM- PONENT POLYCHLORINATED-BIPHENYL-DEGRADING ENZYME IN PSEUDOMONAS STRAIN LB400

    Science.gov (United States)

    The DNA region encoding biphenyl dioxygenase, the first enzyme in the biphenyl-polychlorinated biphenyl degradation pathway of Pseudomonas species strain LB400, was sequenced. Six open reading frames were identified, four of which are homologous to the components of toluene dioxy...

  16. Further studies on the use of enzyme profiles to monitor residue accumulation in wildlife: Plasma enzymes in starlings fed graded concentrations of morsodren, DDE, Aroclor 1254, and malathion

    Science.gov (United States)

    Dieter, M.P.

    1975-01-01

    Wild-trapped starlings (Sturnus vulgaris) were fed concentrations of Morsodren (2, 4, and 8 ppm), DDE or Aroclor 1254 (5, 25, and 100 ppm), or malathion (8, 35, and 160 ppm) that were found to be sublethal in pen-reared Coturnix quail fed these amounts for 12 weeks. Plasma enzymes had to be measured earlier than planned in starlings fed Morsodren (at three weeks) or the organochlorine compounds (at seven weeks) because of unexpected, subsequent mortality. Variations in enzyme response were greater in wild than in pen-reared birds, but not enough to mask the toxicant-induced changes in enzyme activity. Cholinesterase activities decreased in birds fed Morsodren or malathion, and increased in those fed the organochlorine compounds. Lactate dehydrogenase activities increased two-fold in starlings fed Morsodren and two- to four-fold in those fed the organochlorine compounds, but only 50% in those fed malathion. Further examination of enzyme profiles showed that creatine kinase and aspartate aminotransferase activities increased two-to four-fold in birds fed Morsodren or the organochlorine compounds but not at all in those fed malathion. Thus the classes of environmental contaminants fed to starlings could be easily distinguished by these enzymatic parameters. Evaluation of enzymatic profiles appears to be a potentially valuable technique to monitor the presence of toxicants in wild populations, especially if used to complement standard chemical residue analyses. Here the residue analyses showed, after three weeks feeding, that mercury in the carcasses reflected the concentrations fed daily, whereas accumulation in the livers was two- to four-fold greater. After seven weeks feeding, liver residues of either organochlorine compound were about three-fold higher than the concentrations fed daily. However, four times as much DDE as Aroclor 1254 had accumulated in the carcasses.

  17. Consolidated PCBs [polychlorinated biphenyls] improves waste control

    International Nuclear Information System (INIS)

    Smith, E.

    1991-01-01

    Consolidation of polychlorinated biphenyl (PCB) wastes is recommended for improving ownership control of wastes, eliminating PCB storage sites, and increasing cost-effectiveness of waste management. In Ontario, sites receiving the waste must be owned by the waste generator and registered as a PCB site. All PCBs must be removed from a site with no contaminated materials or wastes left behind, which requires a thorough site assessment to identify wastes prior to removal, a sampling and analytical scheme if necessary, and an approved plan for site cleanup. If large volumes of PCB-contaminated oil are involved, it may be cost-effective to put oil from several sites into bulk tanks and thus avoid the need to handle and decontaminate a large number of drums. With low volumes of oil, it may be possible to move the waste to another site where mobile PCB destruction is taking place. It also may be possible to get approval to blend high-level PCB liquids with mineral oil to reduce the PCB concentration to a level where chemical decontamination is allowed. For large volumes of high-level PCB wastes, consolidation will be necessary simply because of the high costs of mobilizing an incinerator and the requirement for public hearings for each incineration project. To make such a project cost-effective, PCB wastes will have to be concentrated from a large geographic area. 1 fig

  18. Crystal structure of 4,4′-bis[3-(piperidin-1-ylprop-1-yn-1-yl]-1,1′-biphenyl

    Directory of Open Access Journals (Sweden)

    Anqi Walbaum

    2017-06-01

    Full Text Available The title compound, C28H32N2, (I, is one of a second generation of compounds designed and synthesized based on a very potent and selective α9α10 nicotinic acetylcholine receptor antagonist ZZ161C {1,1′-[[1,1′-biphenyl]-4,4′-diylbis(prop-2-yne-3,1-diyl]bis(3,4-dimethylpyridin-1-ium bromide}, which has shown analgesic effects in a chemotherapy-induced neuropathy animal model. Compound (I was synthesized by the reaction of 4,4′-bis(3-bromoprop-1-yn-1-yl-1,1′-biphenyl with piperidine at room temperature in acetonitrile. The single-crystal used for X-ray analysis was obtained by dissolving (I in a mixture of dichloromethane and methanol, followed by slow evaporation of the solvent. In the crystal of (I, the biphenyl moiety has a twisted conformation, with a dihedral angle of 25.93 (4° between the benzene rings. Both piperidine head groups in (I are in the chair conformation and are oriented so that the N-atom lone pairs of each piperidine group point away from the central biphenyl moiety.

  19. Biphenyl Modulates the Expression and Function of Respiratory Oxidases in the Polychlorinated-Biphenyls Degrader Pseudomonas pseudoalcaligenes KF707

    Directory of Open Access Journals (Sweden)

    Federica Sandri

    2017-06-01

    Full Text Available Pseudomonas pseudoalcaligenes KF707 is a soil bacterium which is known for its capacity to aerobically degrade harmful organic compounds such as polychlorinated biphenyls (PCBs using biphenyl as co-metabolite. Here we provide the first genetic and functional analysis of the KF707 respiratory terminal oxidases in cells grown with two different carbon sources: glucose and biphenyl. We identified five terminal oxidases in KF707: two c(caa3 type oxidases (Caa3 and Ccaa3, two cbb3 type oxidases (Cbb31 and Cbb32, and one bd type cyanide-insensitive quinol oxidase (CIO. While the activity and expression of both Cbb31 and Cbb32 oxidases was prevalent in glucose grown cells as compared to the other oxidases, the activity and expression of the Caa3 oxidase increased considerably only when biphenyl was used as carbon source in contrast to the Cbb32 oxidase which was repressed. Further, the respiratory activity and expression of CIO was up-regulated in a Cbb31 deletion strain as compared to W.T. whereas the CIO up-regulation was not present in Cbb32 and C(caa3 deletion mutants. These results, together, reveal that both function and expression of cbb3 and caa3 type oxidases in KF707 are modulated by biphenyl which is the co-metabolite needed for the activation of the PCBs-degradation pathway.

  20. OXIDATION OF POLYCHLORINATED BIPHENYLS BY PSEUDOMONAS SP. STRAIN LB400 AND PSEUDOMONAS PSEUDOALCALIGENES KF707

    Science.gov (United States)

    Biphenyl-grown cells and cell extracts prepared from biphenyl-grown cells of Pseudomonas sp. strain LB400 oxidize a much wider range of chlorinated biphenyls than do analogous preparations from Pseudomonas pseudoalcaligenes KF707. These results are attributed to differences in th...

  1. OXIDATION OF BIPHENYL BY A MULTICOMPONENT ENZYME SYSTEM FROM PSEUDOMONAS SP. STRAIN LB400

    Science.gov (United States)

    Pseudomonas sp. strain LB400 grows on biphenyl as the sole carbon and energy source. This organism also cooxidizes several chlorinated biphenyl congeners. Biphenyl dioxygenase activity in cell extract required addition of NAD(P)H as an electron donor for the conversion of bipheny...

  2. Exposure Monitoring and Risk Assessment of Biphenyl in the Workplace

    Directory of Open Access Journals (Sweden)

    Hyeon-Yeong Kim

    2015-05-01

    Full Text Available This study was performed to assess exposure to and the risk caused by biphenyl in the workplace. Biphenyl is widely used as a heat transfer medium and as an emulsifier and polish in industry. Vapor or high levels of dust inhalation and dermal exposure to biphenyl can cause eye inflammation, irritation of respiratory organs, and permanent lesions in the liver and nervous system. In this study, the workplace environment concentrations were assessed as central tendency exposure and reasonable maximum exposure and were shown to be 0.03 and 0.12 mg/m3, respectively. In addition, the carcinogenic risk of biphenyl as determined by risk assessment was 0.14 × 10−4 (central tendency exposure and 0.56 × 10−4 (reasonable maximum exposure, which is below the acceptable risk value of 1.0 × 10−4. Furthermore, the central tendency exposure and reasonable maximum exposure hazard quotients were 0.01 and 0.06 for oral toxicity, 0.05 and 0.23 for inhalation toxicity, and 0.08 and 0.39 for reproduction toxicity, respectively, which are all lower than the acceptable hazard quotient of 1.0. Therefore, exposure to biphenyl was found to be safe in current workplace environments. Because occupational exposure limits are based on socioeconomic assessment, they are generally higher than true values seen in toxicity experiments. Based on the results of exposure monitoring of biphenyl, the current occupational exposure limits in Korea could be reviewed.

  3. Exposure monitoring and risk assessment of biphenyl in the workplace.

    Science.gov (United States)

    Kim, Hyeon-Yeong; Shin, Sae-Mi; Ham, Miran; Lim, Cheol-Hong; Byeon, Sang-Hoon

    2015-05-13

    This study was performed to assess exposure to and the risk caused by biphenyl in the workplace. Biphenyl is widely used as a heat transfer medium and as an emulsifier and polish in industry. Vapor or high levels of dust inhalation and dermal exposure to biphenyl can cause eye inflammation, irritation of respiratory organs, and permanent lesions in the liver and nervous system. In this study, the workplace environment concentrations were assessed as central tendency exposure and reasonable maximum exposure and were shown to be 0.03 and 0.12 mg/m³, respectively. In addition, the carcinogenic risk of biphenyl as determined by risk assessment was 0.14 × 10⁻⁴ (central tendency exposure) and 0.56 × 10⁻⁴ (reasonable maximum exposure), which is below the acceptable risk value of 1.0 × 10⁻⁴. Furthermore, the central tendency exposure and reasonable maximum exposure hazard quotients were 0.01 and 0.06 for oral toxicity, 0.05 and 0.23 for inhalation toxicity, and 0.08 and 0.39 for reproduction toxicity, respectively, which are all lower than the acceptable hazard quotient of 1.0. Therefore, exposure to biphenyl was found to be safe in current workplace environments. Because occupational exposure limits are based on socioeconomic assessment, they are generally higher than true values seen in toxicity experiments. Based on the results of exposure monitoring of biphenyl, the current occupational exposure limits in Korea could be reviewed.

  4. Process for removing halogenated aliphatic and aromatic compounds from petroleum products. [Polychlorinated biphenyls; methylene chloride; perchloroethylene; trichlorofluoroethane; trichloroethylene; chlorobenzene

    Science.gov (United States)

    Googin, J.M.; Napier, J.M.; Travaglini, M.A.

    1982-03-31

    A process for removing halogenated aliphatic and aromatic compounds, e.g., polychlorinated biphenyls, from petroleum products by solvent extraction. The halogenated aliphatic and aromatic compounds are extracted from a petroleum product into a polar solvent by contracting the petroleum product with the polar solvent. The polar solvent is characterized by a high solubility for the extracted halogenated aliphatic and aromatic compounds, a low solubility for the petroleum product and considerable solvent power for polyhydroxy compound. The preferred polar solvent is dimethylformamide. A miscible polyhydroxy compound, such as, water, is added to the polar extraction solvent to increase the polarity of the polar extraction solvent. The halogenated aliphatic and aromatic compounds are extracted from the highly-polarized mixture of polyhydroxy compound and polar extraction solvent into a low polar or nonpolar solvent by contacting the polyhydroxy compound-polar solvent mixture with the low polar or nonpolar solvent. The halogenated aliphatic and aromatic compounds in the low polar or nonpolar solvent by physical means, e.g., vacuum evaporation. The polar and nonpolar solvents are recovered for recycling. The process can easily be designed for continuous operation. Advantages of the process include that the polar solvent and a major portion of the nonpolar solvent can be recycled, the petroleum products are reclaimable and the cost for disposing of waste containing polychlorinated biphenyls is significantly reduced. 2 tables.

  5. Tumour promotion by complex mixtures of polyhalogenated aromatic hydrocarbons (PHAHs) and the applicability of the toxic equivalency factor (TEF) concept

    NARCIS (Netherlands)

    Plas, van der S.A.

    2000-01-01

    The aim of the project described in this thesis consisted of two main objectives, first, to examine the tumour promotion potential of complex, environmentally relevant mixtures of polychlorinated biphenyls (PCBs), polychlorinated dibenzo- p -dioxins (PCDDs) and

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

    Science.gov (United States)

    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...

  7. Congener profiles of polychlorinated biphenyls and the effect on ...

    African Journals Online (AJOL)

    This study investigated the effect of freshwater as a point source of PCBs contributing to a marine outfall region. Inflowing and outflowing water from the North End Lake, Port Elizabeth, was collected to determine the contamination levels of polychlorinated biphenyls (PCBs). Mussels at the outflow to the sea were also ...

  8. Metabolic Pathways of Polychlorinated Biphenyls Degradation by Pseudomonas sp. 2

    Czech Academy of Sciences Publication Activity Database

    Komancová, M.; Jurčová, Irena; Kochánková, L.; Burkhard, J.

    2003-01-01

    Roč. 50, č. 4 (2003), s. 537ů543 ISSN 0045-6535 Institutional research plan: CEZ:AV0Z4072921 Keywords : polychlorinated biphenyls * biodegradation * aerobic bacteria Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.904, year: 2003

  9. Polychlorinated biphenyl exposure and deiodinase activity in young infants

    NARCIS (Netherlands)

    Soechitram, Shalini D.; Berghuis, Sietske A.; Visser, Theo J.; Sauer, Pieter J. J.

    2017-01-01

    Background: Several studies have shown effects of polychlorinated biphenyls (PCBs) on serum thyroid hormone levels in pregnant woman and their infants, while other studies did not find such effects. How PCBs might affect thyroid hormone metabolism, is still unclear. Potential mechanisms are direct

  10. Attenuation of polychlorinated biphenyl sorption to charcoal by humic acids

    NARCIS (Netherlands)

    Koelmans, A.A.; Meulman, B.; Meijer, T.; Jonker, M.T.O.

    2009-01-01

    Strong sorption to black carbon may limit the environmental risks of organic pollutants, but interactions with cosorbing humic acid (HA) may interfere. We studied the attenuative effect of HA additions on the sorption of polychlorinated biphenyls (PCBs) to a charcoal. "Intrinsic" sorption to

  11. Transgenic plants to improve rhizoremediation of polychlorinated biphenyls (PCBs)

    Czech Academy of Sciences Publication Activity Database

    Sylvestre, M.; Macek, Tomáš; Macková, Martina

    2009-01-01

    Roč. 20, č. 2 (2009), s. 242-247 ISSN 0958-1669 R&D Projects: GA MŠk 1M06030 Institutional research plan: CEZ:AV0Z40550506 Keywords : bacterial dioxygenases * GM- plants * polychlorinated biphenyls * rhizoremediation Subject RIV: EI - Biotechnology ; Bionics Impact factor: 7.820, year: 2009

  12. Polychlorinated Biphenyls: In situ Bioremediation from the Environment

    Science.gov (United States)

    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...

  13. Photochemical of Polychlorinated biphenyl by the photolysis and ...

    African Journals Online (AJOL)

    pressure mercury lamp. The whole Lamp was immersed in a reactor thermostat controlling the temperature at 32 ± 2 °C. The Polychlorinated biphenyls (PCBs) were analyzed by GC/ECD. The degradation of PCBs in terms of one, two and three lamp ...

  14. Effects of polychlorinated biphenyls on metamorphosis of a marine fish Japanese flounder (Paralichthys olivaceus) in relation to thyroid disruption.

    Science.gov (United States)

    Dong, Yifei; Zhang, Xiaona; Tian, Hua; Li, Xiang; Wang, Wei; Ru, Shaoguo

    2017-06-15

    This study examined the influence of environmental concentrations of Aroclor 1254 (10, 100, and 1000ng/L) on metamorphosis of Paralichthys olivaceus, and analyzed the mechanisms in relation to thyroid disruption. Results showed that 100 and 1000ng/L Aroclor 1254 delayed metamorphosis and that 1000ng/L Aroclor 1254 caused abnormal morphology. Thyroxine and triiodothyronine levels in the control group were significantly elevated at metamorphic climax, but treatment with 100 and 1000ng/L delayed the increase in thyroid hormones (THs) and retarded metamorphic processes. In larvae exposed to 1000ng/L Aroclor 1254, TH levels at metamorphic climax were significantly lower than those of the control group at the same metamorphic stage. We suggest that the effects of Aroclor 1254 on larval metamorphosis can be explained by disruption of thyroid homeostasis. These findings provide a new perspective and biological model for thyroid-disrupting chemicals (TDCs) screening and investigating interference of thyroid function by TDCs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Concentrations, loads, and sources of polychlorinated biphenyls, Neponset River and Neponset River Estuary, eastern Massachusetts

    Science.gov (United States)

    Breault, Robert F.

    2011-01-01

    Polychlorinated biphenyls (PCBs) are known to contaminate the Neponset River, which flows through parts of Boston, Massachusetts, and empties into the Neponset River Estuary, an important fish-spawning area. The river is dammed and impassable to fish. The U.S. Geological Survey, in cooperation with the Massachusetts Department of Fish and Game, Division of Ecological Restoration, Riverways Program, collected, analyzed, and interpreted PCB data from bottom-sediment, water, and (or) fish-tissue samples in 2002, 2004-2006. Samples from the Neponset River and Neponset River Estuary were analyzed for 209 PCB congeners, PCB homologs, and Aroclors. In order to better assess the overall health quality of river-bottom sediments, sediment samples were also tested for concentrations of 31 elements. PCB concentrations measured in the top layers of bottom sediment ranged from 28 nanograms per gram (ng/g) just upstream of the Mother Brook confluence to 24,900 ng/g measured in Mother Brook. Concentrations of elements in bottom sediment were generally higher than background concentrations and higher than levels considered toxic to benthic organisms according to freshwater sediment-quality guidelines defined by the U.S. Environmental Protection Agency. Concentrations of dissolved PCBs in water samples collected from the Neponset River (May 13, 2005 to April 28, 2006) averaged about 9.2 nanograms per liter (ng/L) (annual average of monthly values); however, during the months of August (about 16.5 ng/L) and September (about 15.6 ng/L), dissolved PCB concentrations were greater than 14 ng/L, the U.S. Environmental Protection Agency's freshwater continuous chronic criterion for aquatic organisms. Concentrations of PCBs in white sucker (fillets and whole fish) were all greater than 2,000 ng/g wet wt, the U.S. Environmental Protection Agency's guideline for safe consumption of fish: PCB concentrations measured in fish-tissue samples collected from the Tileston and Hollingsworth and

  16. Biphenyl-metabolizing bacteria in the rhizosphere of horseradish and bulk soil contaminated by polychlorinated biphenyls as revealed by stable isotope probing.

    Science.gov (United States)

    Uhlik, Ondrej; Jecna, Katerina; Mackova, Martina; Vlcek, Cestmir; Hroudova, Miluse; Demnerova, Katerina; Paces, Vaclav; Macek, Tomas

    2009-10-01

    DNA-based stable isotope probing in combination with terminal restriction fragment length polymorphism was used in order to identify members of the microbial community that metabolize biphenyl in the rhizosphere of horseradish (Armoracia rusticana) cultivated in soil contaminated with polychlorinated biphenyls (PCBs) compared to members of the microbial community in initial, uncultivated bulk soil. On the basis of early and recurrent detection of their 16S rRNA genes in clone libraries constructed from [(13)C]DNA, Hydrogenophaga spp. appeared to dominate biphenyl catabolism in the horseradish rhizosphere soil, whereas Paenibacillus spp. were the predominant biphenyl-utilizing bacteria in the initial bulk soil. Other bacteria found to derive carbon from biphenyl in this nutrient-amended microcosm-based study belonged mostly to the class Betaproteobacteria and were identified as Achromobacter spp., Variovorax spp., Methylovorus spp., or Methylophilus spp. Some bacteria that were unclassified at the genus level were also detected, and these bacteria may be members of undescribed genera. The deduced amino acid sequences of the biphenyl dioxygenase alpha subunits (BphA) from bacteria that incorporated [(13)C]into DNA in 3-day incubations of the soils with [(13)C]biphenyl are almost identical to that of Pseudomonas alcaligenes B-357. This suggests that the spectrum of the PCB congeners that can be degraded by these enzymes may be similar to that of strain B-357. These results demonstrate that altering the soil environment can result in the participation of different bacteria in the metabolism of biphenyl.

  17. Role of inhalation in exposure to polychlorinated biphenyls (PCBs)

    International Nuclear Information System (INIS)

    Monarca, S.; Dominici, L.; Fatigoni, C.

    2007-01-01

    Polychlorinated biphenyls (PCBs) are a group of aromatic compounds consisting of a biphenyl variously chlorinated. Industrial production of PCBs started in 1929 and stopped in the second half of the '70s in USA and in the late 80's and 90's in Europe. PCBs are ubiquitous pollutants. The way of human exposure to PCBs is a matter of discussion. Scientific data show that the greater exposure occurs through diet. However, other available data suggest a not marginal role of the inhalation exposure. The sources of PCBs to which population are exposed depend on the amount of redistribution of these compounds released in the environment. The aim of this work is to highlight numerous studies proving that the intake of PCBs by inhalation cannot be neglected, in particular in heavily industrialized areas and where the concentration of PCBs in the environmental matrices is particularly high

  18. Anaerobic Dehalogenation of Hydroxylated Polychlorinated Biphenyls by Desulfitobacterium dehalogenans

    OpenAIRE

    Wiegel, Juergen; Zhang, Xiaoming; Wu, Qingzhong

    1999-01-01

    Ten years after reports on the existence of anaerobic dehalogenation of polychlorinated biphenyls (PCBs) in sediment slurries, we report here on the rapid reductive dehalogenation of para-hydroxylated PCBs (HO-PCBs), the excreted main metabolites of PCB in mammals, which can exhibit estrogenic and antiestrogenic activities in humans. The anaerobic bacterium Desulfitobacterium dehalogenans completely dehalogenates all flanking chlorines (chlorines in ortho position to the para-hydroxyl group) ...

  19. Polychlorinated biphenyl reduction in lake trout by irradiation and broiling

    International Nuclear Information System (INIS)

    Cichy, R.F.; Zabik, M.E.; Weaver, C.M.

    1979-01-01

    The Great Lakes Environmental contaminants surveys (1974-1975) have concluded that excessive concentrations of polychlorinated biphenyls (PCBs) are present in a specific species of lake trout (Salvelinus namaycush). Over 30 ppM of PCBs have been detected in the edible fillet of this fat trout. The objective of this study was to determine the effect of gamma irradiation combined with broiling on the levels of PCBs in lake trout fillets

  20. Polychlorinated Biphenyl Presence in the Columbia River Corridor

    Energy Technology Data Exchange (ETDEWEB)

    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.

  1. Reactivity of polychlorinated biphenyls in nucleophilic and electrophilic substitutions

    Energy Technology Data Exchange (ETDEWEB)

    Gorbunova, Tatyana I., E-mail: gorbunova@ios.uran.ru [I. Ya. Postovskii Institute of Organic Synthesis, Ural Branch, Russian Academy of Sciences, Kovalevskoy St., 22, Ekaterinburg 620990 (Russian Federation); Subbotina, Julia O. [Ural Federal University named after the first President of Russia B.N. Yeltsin, Mira St., 19, Ekaterinburg 620002 (Russian Federation); Saloutin, Viktor I.; Chupakhin, Oleg N. [I. Ya. Postovskii Institute of Organic Synthesis, Ural Branch, Russian Academy of Sciences, Kovalevskoy St., 22, Ekaterinburg 620990 (Russian Federation)

    2014-08-15

    Graphical abstract: - Highlights: • Quantum chemical calculations were carried out for PCBs congeners. • Calculated descriptors were used to explain the PCBs reactivity in S{sub N} and S{sub E} substitutions. • Obtained data were used to estimate the PCBs reactivity in the S{sub N} reactions. • Calculated descriptors were insufficient to explain the PCBs reactivity in the S{sub E} reactions. • New neutralization methods of the large-capacity PCBs were discussed. - Abstract: To explain the chemical reactivity of polychlorinated biphenyls in nucleophilic (S{sub N}) and electrophilic (S{sub E}) substitutions, quantum chemical calculations were carried out at the B3LYP/6-31G(d) level of the Density Functional Theory in gas phase. Carbon atomic charges in biphenyl structure were calculated by the Atoms-in-Molecules method. Chemical hardness and global electrophilicity index parameters were determined for congeners. A comparison of calculated descriptors and experimental data for congener reactivity in the S{sub N} and S{sub E} reactions was made. It is shown that interactions in the S{sub N} mechanism are reactions of the hard acid–hard base type, these are the most effective in case of highly chlorinated substrates. To explain the congener reactivity in the S{sub E} reactions, correct descriptors were not established. The obtained results can be used to carry out chemical transformations of the polychlorinated biphenyls in order to prepare them for microbiological destruction or preservation.

  2. Complete Reductive Dehalogenation of Brominated Biphenyls by Anaerobic Microorganisms in Sediment

    Science.gov (United States)

    Bedard, Donna L.; Van Dort, Heidi M.

    1998-01-01

    We sought to determine whether microorganisms from the polychlorinated biphenyl (PCB)-contaminated sediment in Woods Pond (Lenox, Mass.) could dehalogenate brominated biphenyls. The PCB dechlorination specificities for the microorganisms in this sediment have been well characterized. This allowed us to compare the dehalogenation specificities for brominated biphenyls and chlorinated biphenyls within a single sediment. Anaerobic sediment microcosms were incubated separately at 25°C with 16 different mono- to tetrabrominated biphenyls (350 μM) and disodium malate (10 mM). Samples were extracted and analyzed by gas chromatography with an electron capture detector and a mass spectrometer detector at various times for up to 54 weeks. All of the tested brominated biphenyls were dehalogenated. For most congeners, including 2,6-dibromobiphenyl (26-BB) and 24-25-BB, the dehalogenation began within 1 to 2 weeks. However, for 246-BB and 2-2-BB, debromination was first observed at 7 and 14 weeks, respectively. Most intermediate products did not persist, but when 2-2-BB was produced as a dehalogenation product, it persisted for at least 15 weeks before it was dehalogenated to 2-BB and then to biphenyl. The dehalogenation specificities for brominated and chlorinated biphenyls were similar: meta and para substituents were generally removed first, and ortho substituents were more recalcitrant. However, the brominated biphenyls were better dehalogenation substrates than the chlorinated biphenyls. All of the tested bromobiphenyls, including those with ortho and unflanked meta and para substituents, were ultimately dehalogenated to biphenyl, whereas their chlorinated counterparts either were not dehalogenation substrates or were only partially dehalogenated. Our data suggest that PCB-dechlorinating microorganisms may be able to dehalogenate brominated biphenyls and may exhibit a relaxed specificity for these substrates. PMID:16349530

  3. 4-Substituted-2-Methoxyphenol: Suitable Building Block to Prepare New Bioactive Natural-like Hydroxylated Biphenyls.

    Science.gov (United States)

    Dettori, Maria Antonietta; Fabbri, Davide; Pisano, Marina; Rozzo, Carla; Palmieri, Giuseppe; Dess, Alessandro; Dallocchio, Roberto; Delogu, Giovanna

    2015-02-01

    A small collection of eugenol- and curcumin-analog hydroxylated biphenyls was prepared by straightforward methods starting from natural 4-substituted-2-methoxyphenols and their antitumoral activity was evaluated in vitro . Two curcumin-biphenyl derivatives showed interesting growth inhibitory activities on different malignant melanoma cell lines with IC 50 ranging from 13 to 1 µM. Preliminary molecular modeling studies were carried out to evaluate conformations and dihedral angles suitable for antiproliferative activity in hydroxylated biphenyls bearing a side aliphatic chain.

  4. Optimal mixture experiments

    CERN Document Server

    Sinha, B K; Pal, Manisha; Das, P

    2014-01-01

    The book dwells mainly on the optimality aspects of mixture designs. As mixture models are a special case of regression models, a general discussion on regression designs has been presented, which includes topics like continuous designs, de la Garza phenomenon, Loewner order domination, Equivalence theorems for different optimality criteria and standard optimality results for single variable polynomial regression and multivariate linear and quadratic regression models. This is followed by a review of the available literature on estimation of parameters in mixture models. Based on recent research findings, the volume also introduces optimal mixture designs for estimation of optimum mixing proportions in different mixture models, which include Scheffé’s quadratic model, Darroch-Waller model, log- contrast model, mixture-amount models, random coefficient models and multi-response model.  Robust mixture designs and mixture designs in blocks have been also reviewed. Moreover, some applications of mixture desig...

  5. Ortho-substituent correlated retention of polychlorinated biphenyls on a 50% n-octyl-methylpolysiloxane stationary phase by HRGC/MSD

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, R.; Ballschmiter, K.

    1988-11-01

    Polychlorinated biphenyls (PCB) have been known as ubiquitous environmental pollutants since the late 60s. They are found partitioned between all environmental compartments according to their physico-chemical properties. Investigation of their partitioning, degradation, and transport behaviour demands sensitive and selective analytical methods for this complex mixture of up to 209 theoretically possible compounds. Congener-specific separation by high-resolution gas chromatography coupled with mass-selective detection would be a suitable approach to this multi-compound problem. In this paper, the separation of PCB congeners by capillary gas chromatography (HRGC) on a 50% n-octyl-methylpolysiloxane phase is presented.

  6. Role of rhizosphere microorganisms in phytoremediation of biphenyl in a contaminated groundwater plume

    International Nuclear Information System (INIS)

    Sun, B.; Ramsay, J.

    2007-01-01

    This presentation discussed a pump and treat technology used in combination with a phytoremediation technology to remediate a biphenyl contaminated groundwater plume. Biphenyl is used in industrial applications as fungicide and heat transfer agent. It is highly toxic, has poor water solubility and sorbs strongly to soils. Costs for the project were estimated at $860,000 over a period of 20 years, while it was estimated that the addition of phytoremediation would cost only $125,000 over a period of 20 years. The phytoremediation containment area was added to the site which was comprised of a pump and treat system and landfill lagoons. In situ biodegradation of biphenyl was evaluated using microorganisms in poplar and willow rhizospheres. Basal salts were used as a culture medium. Methods to enhance biphenyl degradation were also investigated. Aerobic growth on biphenyl at temperatures of 8 degrees C were measured, and microbial populations were identified. The consortium with the highest biphenyl degradation was then analyzed. Major members were identified as Burkholderia xenovorans LB400 and a strain of Burkholderia xenovorans. Nitrate reduction, sulphate reduction, and methanogens were measured. Enrichment of anaerobic biphenyl degraders. Anaerobic biphenyl degradation was measured after 90 days. Details of anaerobic mineralization experiments were also provided. It was concluded that anaerobic biphenyl degradation was enhanced by TEA and fertilizer addition, as well as by poplar root exudate. tabs., figs

  7. Synergistic Processing of Biphenyl and Benzoate: Carbon Flow Through the Bacterial Community in Polychlorinated-Biphenyl-Contaminated Soil

    Science.gov (United States)

    Leewis, Mary-Cathrine; Uhlik, Ondrej; Leigh, Mary Beth

    2016-02-01

    Aerobic mineralization of PCBs, which are toxic and persistent organic pollutants, involves the upper (biphenyl, BP) and lower (benzoate, BZ) degradation pathways. The activity of different members of the soil microbial community in performing one or both pathways, and their synergistic interactions during PCB biodegradation, are not well understood. This study investigates BP and BZ biodegradation and subsequent carbon flow through the microbial community in PCB-contaminated soil. DNA stable isotope probing (SIP) was used to identify the bacterial guilds involved in utilizing 13C-biphenyl (unchlorinated analogue of PCBs) and/or 13C-benzoate (product/intermediate of BP degradation and analogue of chlorobenzoates). By performing SIP with two substrates in parallel, we reveal microbes performing the upper (BP) and/or lower (BZ) degradation pathways, and heterotrophic bacteria involved indirectly in processing carbon derived from these substrates (i.e. through crossfeeding). Substrate mineralization rates and shifts in relative abundance of labeled taxa suggest that BP and BZ biotransformations were performed by microorganisms with different growth strategies: BZ-associated bacteria were fast growing, potentially copiotrophic organisms, while microbes that transform BP were oligotrophic, slower growing, organisms. Our findings provide novel insight into the functional interactions of soil bacteria active in processing biphenyl and related aromatic compounds in soil, revealing how carbon flows through a bacterial community.

  8. Polychlorinated biphenyls (PCBs) in indoor air originating from sealants in contaminated and uncontaminated apartments within the same housing estate

    DEFF Research Database (Denmark)

    Frederiksen, Marie; Meyer, Harald William; Ebbehøj, Niels Erik

    2012-01-01

    . The PCB(tot) levels in the air of the contaminated section were 168-3843 ng m(-3) (mean: 1030 ng m(-3)), while the mean levels in the reference apartments were 6.03 ng m(-3). The sum of the 24 measured PCB congeners in sealants from the contaminated section was 187-221680 mg kg(-1). Principal component......Twenty-four congeners of polychlorinated biphenyls (PCBs) were measured in 83 air samples and 20 elastic sealants samples of apartments with PCB-containing sealants. In addition, PCBs were measured in 21 air samples from reference apartments located in an uncontaminated section of the same estate...... analysis revealed four groups among the sealant samples with different congener compositions, only two of which were clearly similar to known PCB mixtures, while two were not. Significant correlations and intercorrelations were observed between the lower chlorinated congeners in air and sealant, e...

  9. Gas chromatography/multiphoton ionization/time-of-flight mass spectrometry of polychlorinated biphenyls

    International Nuclear Information System (INIS)

    Matsui, Taiki; Uchimura, Tomohiro; Imasaka, Totaro

    2011-01-01

    A sample mixture of polychlorinated biphenyls (PCBs) was measured by gas chromatography/multiphoton ionization/time-of-flight mass spectrometry (GC/MPI/TOF-MS) using four types of laser sources. When a fourth harmonic emission (266 nm) of a picosecond Nd:YAG laser (1064 nm) was utilized, highly chlorinated PCBs larger than hepta-CBs were not observed. A fifth harmonic emission (213 nm) of the picosecond Nd:YAG laser allowed the measurement of PCBs from di-CBs to octa-CBs, and the limit of detection (LOD) was several pg for each component of PCBs. The LOD for the total amount of PCBs, which was calculated using the protocol provided by the Ministry of the Environment, Japan, was 1000 pg. The signal intensity of the congeners with chlorine atoms at the ortho positions (non-coplanar PCBs) was enhanced by using the fifth harmonic emission. When the fourth harmonic emission remaining after fifth harmonic generation was simultaneously used, the LOD for total PCBs was improved to 667 pg. The PCB sample was also measured using a third harmonic emission (267 nm) of a femtosecond Ti:sapphire laser (800 nm), providing an LOD of 677 pg. Thus, the two-color beam (266/213 nm) of a picosecond Nd:YAG laser had a comparable, or even slightly superior, performance to the more expensive femtosecond Ti:sapphire laser.

  10. Polychlorinated biphenyl (PCB) induction of CYP3A4 enzyme activity in healthy Faroese adults

    DEFF Research Database (Denmark)

    Petersen, Maria Skaalum; Halling, Jónrit; Damkier, Per

    2007-01-01

    The CYP3A4 enzyme is, along with other cytochrome P450 enzymes, involved in the metabolism of environmental pollutants and is highly inducible by these substances. A commercial polychlorinated biphenyl (PCB) mixture, 1,1,1,-trichloro-2-(o-chlorophenyl), 2-(p'-chlorophenyl)ethane (o,p'-DDT) and 1......,1,-dichloro-2,2-bis (p-chlorophenyl)ethene (p,p'-DDE) are known to induce CYP3A4 activity through activation of nuclear receptors, such as the pregnane X receptor. However, this induction of CYP3A4 has not yet been investigated in humans. Thus, the aim of the study was to determine the variability of the CYP3......A4 phenotype in regard to increased concentrations of PCBs and other persistent organohalogen pollutants (POPs) in healthy Faroese adults. In 310 randomly selected Faroese residents aged 18-60 years, the CYP3A4 activity was determined based on the urinary 6beta-hydroxycortisol/cortisol (6beta...

  11. Combined effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin and polychlorinated biphenyls congeners in rats

    Energy Technology Data Exchange (ETDEWEB)

    Chu, I. [Environmental Science Bureau, Ottawa (Canada); Valli, V.E. [Coll. of Veterinary Medicine, Urbana (United States)

    2004-09-15

    There has been considerable interest in conducting toxicity studies on mixtures since this approach represents realistic human exposure and would provide a better model to predict the health impacts of environmental chemicals. However, risk assessment of the chemicals is largely based on the toxicity data of individual compounds by assuming simple additive effects of these compounds. This practice has been accepted by regulatory agencies provided that the concentrations of chemicals are extremely low, and there are no interactions. The existence of interactions among the chemicals co-administered to test animals may under or over estimate the effects of a mixture if the simple additive rule is applied. Previously, we demonstrated an antagonistic effect in rats when tetrachlorodibenzo-p-dioxin (TCDD) was co-administered with polychlorinated biphenyls congeners (PCBs). The hepatic microsomal EROD, MROD and UDPGT activities of TCDD were decreased when co-administered with PCB congeners. To further explore the combined effects of these pollutants, we examined and report results on tissue residue levels of TCDD and histopathological changes in target organs of rats exposed to TCDD, PCBs and mixtures of both.

  12. Liquids and liquid mixtures

    CERN Document Server

    Rowlinson, J S; Baldwin, J E; Buckingham, A D; Danishefsky, S

    2013-01-01

    Liquids and Liquid Mixtures, Third Edition explores the equilibrium properties of liquids and liquid mixtures and relates them to the properties of the constituent molecules using the methods of statistical thermodynamics. Topics covered include the critical state, fluid mixtures at high pressures, and the statistical thermodynamics of fluids and mixtures. This book consists of eight chapters and begins with an overview of the liquid state and the thermodynamic properties of liquids and liquid mixtures, including vapor pressure and heat capacities. The discussion then turns to the thermodynami

  13. Ideal gas thermodynamic properties for the phenyl, phenoxy, and o-biphenyl radicals

    Science.gov (United States)

    Burcat, A.; Zeleznik, F. J.; Mcbride, B. J.

    1985-01-01

    Ideal gas thermodynamic properties of the phenyl and o-biphenyl radicals, their deuterated analogs and the phenoxy radical were calculated to 5000 K using estimated vibrational frequencies and structures. The ideal gas thermodynamic properties of benzene, biphenyl, their deuterated analogs and phenyl were also calculated.

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

    International Nuclear Information System (INIS)

    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

  15. Biphenyl-Metabolizing Bacteria in the Rhizosphere of Horseradish and Bulk Soil Contaminated by Polychlorinated Biphenyls as Revealed by Stable Isotope Probing▿ †

    Science.gov (United States)

    Uhlik, Ondrej; Jecna, Katerina; Mackova, Martina; Vlcek, Cestmir; Hroudova, Miluse; Demnerova, Katerina; Paces, Vaclav; Macek, Tomas

    2009-01-01

    DNA-based stable isotope probing in combination with terminal restriction fragment length polymorphism was used in order to identify members of the microbial community that metabolize biphenyl in the rhizosphere of horseradish (Armoracia rusticana) cultivated in soil contaminated with polychlorinated biphenyls (PCBs) compared to members of the microbial community in initial, uncultivated bulk soil. On the basis of early and recurrent detection of their 16S rRNA genes in clone libraries constructed from [13C]DNA, Hydrogenophaga spp. appeared to dominate biphenyl catabolism in the horseradish rhizosphere soil, whereas Paenibacillus spp. were the predominant biphenyl-utilizing bacteria in the initial bulk soil. Other bacteria found to derive carbon from biphenyl in this nutrient-amended microcosm-based study belonged mostly to the class Betaproteobacteria and were identified as Achromobacter spp., Variovorax spp., Methylovorus spp., or Methylophilus spp. Some bacteria that were unclassified at the genus level were also detected, and these bacteria may be members of undescribed genera. The deduced amino acid sequences of the biphenyl dioxygenase α subunits (BphA) from bacteria that incorporated [13C]into DNA in 3-day incubations of the soils with [13C]biphenyl are almost identical to that of Pseudomonas alcaligenes B-357. This suggests that the spectrum of the PCB congeners that can be degraded by these enzymes may be similar to that of strain B-357. These results demonstrate that altering the soil environment can result in the participation of different bacteria in the metabolism of biphenyl. PMID:19700551

  16. Biobatteries and biofuel cells with biphenylated carbon nanotubes

    Science.gov (United States)

    Stolarczyk, Krzysztof; Kizling, Michał; Majdecka, Dominika; Żelechowska, Kamila; Biernat, Jan F.; Rogalski, Jerzy; Bilewicz, Renata

    2014-03-01

    Single-walled carbon nanotubes (SWCNTs) covalently biphenylated are used for the construction of cathodes in a flow biobattery and in flow biofuel cell. Zinc covered with a hopeite layer is the anode in the biobattery and glassy carbon electrode covered with bioconjugates of single-walled carbon nanotubes with glucose oxidase and catalase is the anode of the biofuel cell. The potentials of the electrodes are measured vs. the Ag/AgCl reference electrode under changing loads of the fuel cell/biobattery. The power density of the biobattery with biphenylated nanotubes at the cathode is ca. 0.6 mW cm-2 and the open circuit potential is ca. 1.6 V. In order to obtain larger power densities and voltages three biobatteries are connected in a series which leads to the open circuit potential of ca. 4.8 V and power density 2.1 mW cm-2 at 3.9 V under 100 kΩ load. The biofuel cell shows power densities of ca. 60 μW cm-2 at 20 kΩ external resistance but the open circuit potential for such biofuel cell is only 0.5 V. The biobattery showing significantly larger power densities and open circuit voltages are especially useful for testing novel cathodes and applications such as powering units for clocks and sensing devices.

  17. Momentum space analysis of the electronic structure of biphenyl

    International Nuclear Information System (INIS)

    Morini, F; Shojaei, S H Reza; Deleuze, M S

    2014-01-01

    The results of a yet to come experimental study of the electronic structure of biphenyl employing electron momentum spectroscopy (EMS) have been theoretically predicted, taking into account complications such as structural mobility in the electronic ground state, electronic correlation and relaxation, and a dispersion of the inner-valence ionization intensity to electronically excited (shake-up) configurations in the cation. The main purpose of this work is to explore the current limits of EMS in unraveling details of the molecular structure, namely the torsional characteristics of large and floppy aromatic molecules. At the benchmark ADC(3)/cc-pVDZ level of theory, the influence of the twist angle between the two phenyl rings is found to be extremely limited, except for individual orbital momentum profiles corresponding to ionization lines at electron binding energies ranging from 15 to 18 eV. When taking band overlap effects into account, this influence is deceptively far too limited to allow for any experimental determination of the torsional characteristics of biphenyl by means of EMS. (paper)

  18. Comment on "Exposure to mercury and Aroclor 1268 congeners in least terns (Sternula antillarum) in coastal Georgia, USA" by G. L. Robinson, G. L. Mills, A. H. Lindell, S. H. Schweitzer and S. M. Hernandez, Environmental Science: Processes & Impacts, 2015, 17, 1424.

    Science.gov (United States)

    Fuchsman, P C; Henning, M H; Magar, V S

    2016-02-01

    In a recent paper published in this journal (Robinson et al., Environmental Science: Processes & Impacts, 2015, 17, 1424), Robinson et al. reported concentrations of Aroclor 1268 congeners in least tern eggs in coastal Georgia, USA. This comment describes important omissions in Robinson et al.'s interpretation of those egg concentrations that alter the overall conclusions of the least tern study.

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

    Science.gov (United States)

    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.

  20. Vapor solvent decontamination of PCB [polychlorinated biphenyls] transformer components

    International Nuclear Information System (INIS)

    Green, G.R.; Green, G.R.

    1992-01-01

    A process is provided to recover reclaimable material from discarded transformers containing PCB (polychlorinated biphenyl) insulating oils and to minimize the volume of materials which are subject to environmental regulation upon disposal. According to the invention, the transformer is drained and given an initial cleaning. The internal parts are removed and cleaned a second time as is the empty transformer casing. Recoverable materials such as aluminum and copper are cleaned to less than 10 μg of PCB per 100 cm 2 , allowing these materials to be recycled rather than buried. Almost all of the remaining nonmetallic materials are combustible solids or liquids which can be destroyed by incineration. The cleaning is accomplished using trichloroethylene solvent, chosen for its low boiling point which makes it easy to recycle using an isothermal separator. The removed transformer parts are cleaned in a secondary cleaning station consisting of 3 separate sections including tumbling baskets. 2 figs

  1. Kinetics of polychlorinated biphenyl partitioning to marine Chrysophyte Isochrysis galbana

    International Nuclear Information System (INIS)

    Ko, Fung-Chi; Baker, Joel E.; Tew, Kwee S.

    2012-01-01

    This study focused on the uptake kinetics of polychlorinated biphenyl (PCB) congeners by the Chrysophyte, Isochrysis galbana. A gas-purging experimental system was used to maintain constant dissolved PCB concentrations. Three phases of absorption were observed: first, a rapid absorption phase within the first 15 min, second, a first order process reaching the maximum concentration within 48 h of exposure, and third, a plateau phase as yet to be determined with very slight increases in concentration. In this study, the percentage of the maximum concentration reached within the first phase varied from 10% to 67%, depending on the size of the PCB (as determined by molecular weight and total surface area), whereas the uptake rate (k u ) during the second phase was more comparable across different PCBs. In addition, for the first phase, the bioconcentration factor (BCF) of PCBs deviated from its expected relationship with hydrophobicity, as determined by K ow , and was instead related to the molecular structure of the compound.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. Phytoremediation of Polychlorinated Biphenyls: New Trends and Promises

    Science.gov (United States)

    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. Perception of trigeminal mixtures.

    Science.gov (United States)

    Filiou, Renée-Pier; Lepore, Franco; Bryant, Bruce; Lundström, Johan N; Frasnelli, Johannes

    2015-01-01

    The trigeminal system is a chemical sense allowing for the perception of chemosensory information in our environment. However, contrary to smell and taste, we lack a thorough understanding of the trigeminal processing of mixtures. We, therefore, investigated trigeminal perception using mixtures of 3 relatively receptor-specific agonists together with one control odor in different proportions to determine basic perceptual dimensions of trigeminal perception. We found that 4 main dimensions were linked to trigeminal perception: sensations of intensity, warmth, coldness, and pain. We subsequently investigated perception of binary mixtures of trigeminal stimuli by means of these 4 perceptual dimensions using different concentrations of a cooling stimulus (eucalyptol) mixed with a stimulus that evokes warmth perception (cinnamaldehyde). To determine if sensory interactions are mainly of central or peripheral origin, we presented stimuli in a physical "mixture" or as a "combination" presented separately to individual nostrils. Results showed that mixtures generally yielded higher ratings than combinations on the trigeminal dimensions "intensity," "warm," and "painful," whereas combinations yielded higher ratings than mixtures on the trigeminal dimension "cold." These results suggest dimension-specific interactions in the perception of trigeminal mixtures, which may be explained by particular interactions that may take place on peripheral or central levels. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. Polychlorinated biphenyl (PCB) induction of CYP3A4 enzyme activity in healthy Faroese adults

    International Nuclear Information System (INIS)

    Petersen, Maria Skaalum; Halling, Jonrit; Damkier, Per; Nielsen, Flemming; Grandjean, Philippe; Weihe, Pal; Brosen, Kim

    2007-01-01

    The CYP3A4 enzyme is, along with other cytochrome P450 enzymes, involved in the metabolism of environmental pollutants and is highly inducible by these substances. A commercial polychlorinated biphenyl (PCB) mixture, 1,1,1,-trichloro-2-(o-chlorophenyl), 2-(p'-chlorophenyl)ethane (o,p'-DDT) and 1,1,-dichloro-2,2-bis (p-chlorophenyl)ethene (p,p'-DDE) are known to induce CYP3A4 activity through activation of nuclear receptors, such as the pregnane X receptor. However, this induction of CYP3A4 has not yet been investigated in humans. Thus, the aim of the study was to determine the variability of the CYP3A4 phenotype in regard to increased concentrations of PCBs and other persistent organohalogen pollutants (POPs) in healthy Faroese adults. In 310 randomly selected Faroese residents aged 18-60 years, the CYP3A4 activity was determined based on the urinary 6β-hydroxycortisol/cortisol (6β-OHC/FC) ratio. POP exposures were assessed by measuring their concentrations in serum lipid. The results showed a unimodal distribution of the 6β-OHC/FC ratio with values ranging from 0.58 to 27.38. Women had a slightly higher 6β-OHC/FC ratio than men (p = 0.07). Confounder-adjusted multiple regression analysis showed significant associations between 6β-OHC/FC ratios and ΣPCB, PCB-TEQ and p,p'-DDE, o,p'-DDT and HCB, respectively, but the associations were statistically significant for men only

  6. Chronic treatment with polychlorinated biphenyls (PCB) during pregnancy and lactation in the rat

    International Nuclear Information System (INIS)

    Colciago, A.; Casati, L.; Mornati, O.; Vergoni, A.V.; Santagostino, A.; Celotti, F.; Negri-Cesi, P.

    2009-01-01

    The gender-specific expression pattern of aromatase and 5alpha-reductases (5alpha-R) during brain development provides neurons the right amount of estradiol and DHT to induce a dimorphic organization of the structure. Polychlorinated biphenyls (PCBs) are endocrine disruptive pollutants; exposure to PCBs through placental transfer and breast-feeding may adversely affect the organizational action of sex steroid, resulting in long-term alteration of reproductive neuroendocrinology. The study was aimed at: a) evaluating the hypothalamic expression of aromatase, 5alpha-R1 and 5alpha-R2 in fetuses (GD20), infant (PN12), weaning (PN21) and young adult (PN60) male and female rats exposed to PCBs during development; b) correlating these parameters with the time of testicular descent, puberty onset, estrous cyclicity and copulatory behavior; c) evaluating possible alterations of some non reproductive behaviors (locomotion, learning and memory, depression/anxiety behavior). A reconstituted mixture of four indicator congeners (PCB 126, 138, 153 and 180) was injected subcutaneously to dams at the dose of 10 mg/kg daily from GD15 to GD19 and then twice a week till weanling. The results indicated that developmental PCB exposure produced important changes in the dimorphic hypothalamic expression of both aromatase and the 5alpha-Rs, which were still evident in adult animals. We observed that female puberty onset occurs earlier than in control animals without cycle irregularity, while testicular descent in males was delayed. A slight but significant impairment of sexual behavior and an important alteration in memory retention were also noted specifically in males. We conclude that PCBs might affect the dimorphic neuroendocrine control of reproductive system and of other neurobiological processes.

  7. The levels of polychlorinated biphenyls in 1,4-dichlorobenzene mothballs

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wenbin; Zheng, Minghui; Xing, Ying; Wang, Dongshen; Zhao, Xingru; Gao, Lirong [Chinese Academy of Sciences, Beijing (China). Key laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences

    2004-09-15

    The chemical 1,4-dichlorobenzene (p-DCB), also called paramoth, is one of the chemicals commonly used to make mothballs. For the more than 20 years, p-DCB has been used principally (35-55% of all uses) as a space deodorant for toilets and refuse containers, and as a fumigant for control of moths, molds, and mildews. The process of production of p-DCB currently used by industry is direct chlorination of benzene or chlorobenzene in the presence of a Friedel-Crafts catalyst (typically FeCl{sub 3}), and the pure products of p-DCB are obtained by distillation and crystallization from the mixture of polychlorinated benzenes. This process is similar to that of production of PCBs which were manufactured commercially by the progressive chlorination of biphenyl in the presence of a suitable catalyst, e.g., iron chloride. However, few studies on the formation of PCBs from chlorobenzenes have been published. Buser reported significant quantities of PCDFs and a small amount of PCDDs, PCBs, and chlorophenols were formed in the pyrolysis of chlorobenzenes at 620 C. Peng-Yan Liu et al. revealed that lower chlorinated benzenes produce more PCBs than higher ones. Nevertheless, prior to this study, no reports on PCBs in p-DCB and the restriction of PCBs in p-DCB products have been found. In this paper, the occurrence and distribution of dioxin-like PCBs and total PCBs in some commercial p-DCB mothballs are investigated. Except of the toxic of p-DCB, the low concentration of PCBs in p-DCB mothballs should not be negligible.

  8. Environmental Polychlorinated Biphenyl Exposure and Breast Cancer Risk: A Meta-Analysis of Observational Studies.

    Directory of Open Access Journals (Sweden)

    Jingwen Zhang

    Full Text Available Association between polychlorinated biphenyl (PCB exposure and breast cancer risk has been widely studied, but the results remain controversial. We performed a meta-analysis to evaluate the evidences from observational studies on PCB exposure and breast cancer risk.Relevant studies with data on internal PCB dose were identified from PubMed, EMBASE, CBM and CNKI databases through November 2014. Multivariable-adjusted odds ratio (OR with 95% confidence intervals (CIs were applied to assess the association between PCB exposure and breast cancer risk. Heterogeneity test, sensitivity analysis, subgroup analysis and publication bias test were also performed. To further explore the association between specific groups of PCB congeners and breast cancer, we examined the PCB congeners classified, according to their structural, biological and pharmacokinetics properties, as group I (potentially estrogenic, group II (potentially anti-estrogenic and immunotoxic, dioxin-like, and group III (phenobarbital, CYP1A and CYP2B inducers, biologically persistent.Of 660 studies screened, 25 studies which met criteria were selected, involving a total of 12866 participants (6088 cases and 6778 controls from eight countries. The results showed that the risk of breast cancer was associated with group II (OR = 1.23, 95% CI: 1.08-1.40 and group III (OR = 1.25, 95% CI: 1.09-1.43 PCBs, but not with group I (OR = 1.10, 95%CI: 0.97-1.24 PCBs or total PCB exposure (OR = 1.09, 95%CI: 0.97-1.22.Our meta-analysis based on the selected studies found group II and group III PCB exposure might contribute to the risk of breast cancer. More studies in developing countries with higher PCB levels are needed, as well as studies to explore the relationships between mixtures of organochlorine compounds and breast cancer risk.

  9. Iterative Mixture Component Pruning Algorithm for Gaussian Mixture PHD Filter

    Directory of Open Access Journals (Sweden)

    Xiaoxi Yan

    2014-01-01

    Full Text Available As far as the increasing number of mixture components in the Gaussian mixture PHD filter is concerned, an iterative mixture component pruning algorithm is proposed. The pruning algorithm is based on maximizing the posterior probability density of the mixture weights. The entropy distribution of the mixture weights is adopted as the prior distribution of mixture component parameters. The iterative update formulations of the mixture weights are derived by Lagrange multiplier and Lambert W function. Mixture components, whose weights become negative during iterative procedure, are pruned by setting corresponding mixture weights to zeros. In addition, multiple mixture components with similar parameters describing the same PHD peak can be merged into one mixture component in the algorithm. Simulation results show that the proposed iterative mixture component pruning algorithm is superior to the typical pruning algorithm based on thresholds.

  10. Spermatogenic capacity in fertile men with elevated exposure to polychlorinated biphenyls

    DEFF Research Database (Denmark)

    Petersen, Maria Skaalum; Halling, Jónrit; Weihe, Pál

    2015-01-01

    BACKGROUND: Endocrine disrupting industrial chemicals, such as polychlorinated biphenyls (PCBs), are suspected to adversely affect male reproductive functions. OBJECTIVES: The Faroe Islands community exhibits an unusually wide range of exposures to dietary contaminants, and in this setting we...

  11. Preliminary results of the comparison of the electrochemical behavior of a thioether and biphenyl

    Science.gov (United States)

    Morales, W.; Jones, W. R.

    1983-01-01

    An electrochemical cell was constructed to explore the feasibility of using electrochemical techniques to simulate the tribochemistry of various substances. The electrochemical cell was used to study and compare the behavior of a thioether 1,3-bis(phenylthio) benzene and biphenyl. It is found that under controlled conditions biphenyl undergoes a reversible reduction to a radical anion whereas the thioether undergoes an irreversible reduction yielding several products. The results are discussed in relationship to boundary lubrication.

  12. Regional analysis of potential polychlorinated biphenyl degrading bacterial strains from China

    Directory of Open Access Journals (Sweden)

    Jianjun Shuai

    Full Text Available ABSTRACT Polychlorinated biphenyls (PCBs, the chlorinated derivatives of biphenyl, are one of the most prevalent, highly toxic and persistent groups of contaminants in the environment. The objective of this study was to investigate the biodegradation of PCBs in northeastern (Heilongjiang Province, northern (Shanxi Province and eastern China (Shanghai municipality. From these areas, nine soil samples were screened for PCB-degrading bacteria using a functional complementarity method. The genomic 16S rDNA locus was amplified and the products were sequenced to identify the bacterial genera. Seven Pseudomonas strains were selected to compare the capacity of bacteria from different regions to degrade biphenyl by HPLC. Compared to the biphenyl content in controls of 100%, the biphenyl content went down to 3.7% for strain P9-324, 36.3% for P2-11, and 20.0% for the other five strains. These results indicate that a longer processing time led to more degradation of biphenyl. PCB-degrading bacterial strains are distributed differently in different regions of China.

  13. Photochemical of Polychlorinated biphenyl by the photolysis and ...

    African Journals Online (AJOL)

    Michael Horsfall

    reaction mixture inside the cell was continuously stirred with a .... work on PCB photolysis was carried out in alkanes and alcohols. .... dominant mechanism of PCBs destruction becomes hydroxyl ... (2004). Using solar and ultraviolet light to.

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

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Linyan; Su, Guijin, E-mail: gjsu@rcees.ac.cn; Zhang, Aiqian; Shi, Yali; Xia, Chaobo; Lu, Huijie; Li, Liewu; Liu, Sha; Zheng, Minghui

    2013-10-15

    Highlights: • The NiFe{sub 2}O{sub 4} had the highest activity in degradation of CB-209, followed by Fe{sub 3}O{sub 4}. • Hydroxyl species, organic acids, PCBs and chlorobenzenes were identified as products. • Three degradation reactions and one combination reaction competitively occurred. • Hydrodechlorination of CB-209 was more favored over Fe{sub 3}O{sub 4} than NiFe{sub 2}O{sub 4}. • Oxidation reaction of CB-209 was more favored over NiFe{sub 2}O{sub 4} than Fe{sub 3}O{sub 4}. -- Abstract: 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 NiFe{sub 2}O{sub 4} had the highest DE, followed by Fe{sub 3}O{sub 4}. 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 C-C 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 C-Cl 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 Fe{sub 3}O{sub 4} into Fe{sub 2}O{sub 3} in the Fe{sub 3}O{sub 4} reaction system, and the existence of the highly reactive O{sub 2}{sup −}· species in the NiFe{sub 2}O{sub 4} reaction system, could provide a reason why the oxidation reaction was more favored over NiFe{sub 2}O

  15. The use of the DR CALUX bioassay and indicator polychlorinated biphenyls for screening of elevated levels of dioxins and dioxin-like polychlorinated biphenyls in eel.

    NARCIS (Netherlands)

    Hoogenboom, Ron; Bovee, Toine; Traag, Win A; Hoogerbrugge, Ronald; Baumann, Bert; Portier, Liza; Weg, Guido van de; Vries, Jaap de

    2006-01-01

    The DR CALUX bioassay is a very suitable screening method for dioxins and dioxin-like-PCBs in feed and food. This was, e. g. demonstrated in a survey in the Netherlands to control the dioxin levels in eel. The DR CALUX assay, but also indicator polychlorinated biphenyls (PCB) were evaluated as a

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

    International Nuclear Information System (INIS)

    Taylor, Kira C.; Jackson, Leila W.; Lynch, Courtney D.; Kostyniak, Paul J.; Buck Louis, Germaine M.

    2007-01-01

    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

  17. Phytoremediation of soil contaminated with cadmium, copper and polychlorinated biphenyls.

    Science.gov (United States)

    Wu, Longhua; Li, Zhu; Han, Cunliang; Liu, Ling; Teng, Ying; Sun, Xianghui; Pan, Cheng; Huang, Yujuan; Luo, Yongming; Christie, Peter

    2012-07-01

    A pot experiment and afield trial were conducted to study the remediation of an aged field soil contaminated with cadmium, copper and polychlorinated biphenyls (PCBs) (7.67 +/- 0.51 mg kg(-1) Cd, 369 +/- 1 mg kg(-1) Cu in pot experiment; 8.46 +/- 0.31 mg kg(-1) Cd, 468 +/- 7 mg kg(-1) Cu, 323 +/- 12 microg kg(-1) PCBs for field experiment) under different cropping patterns. In the pot experiment Sedum plumbizincicola showed pronounced Cd phytoextraction. After two periods (14 months) of cropping the Cd removal rates in these two treatments were 52.2 +/- 12.0 and 56.1 +/- 9.1%, respectively. Total soil PCBs in unplanted control pots decreased from 323 +/- 11 to 49.3 +/- 6.6 microg kg(-1), but with no significant difference between treatments. The field microcosm experiment intercropping of three plant species reduced the yield of S. plumbizincicola, with a consequent decrease in soil Cd removal. S. plumbizincicola intercropped with E. splendens had the highest shoot Cd uptake (18.5 +/- 1.8 mg pot(-1)) after 6 months planting followed by intercropping with M. sativa (15.9 +/- 1.9 mg pot(-1)). Liming with S. plumbizincicola intercropped with M. sativa significantly promoted soil PCB degradation by 25.2%. Thus, adjustment of soil pH to 5.56 combined with intercropping with S. plumbizincicola and M. sativagave high removal rates of Cd, Cu, and PCBs.

  18. Sex effect on polychlorinated biphenyl concentrations in fish: a synthesis

    Science.gov (United States)

    Madenjian, C.P.

    2011-01-01

    Polychlorinated biphenyls (PCBs) accumulate in fish primarily via food intake, and therefore, PCBs serve as a chemical tracer for food consumption. Sex differences in PCB concentrations of fish have been attributed to the following three mechanisms: (i) females losing a substantial portion of their PCB body burden during spawning and consequently their PCB concentration is considerably reduced immediately after spawning; (ii) sex differences in habitat utilization leading to sex differences in the PCB concentrations of the prey; and (iii) sex differences in gross growth efficiency, which is defined as growth divided by the amount of food consumption needed to achieve that growth. Based on my analyses and synthesis, mechanisms (i) and (ii) operate in relatively few fish populations, but can lead to mature males having PCB concentrations two to three times higher than mature female PCB concentrations. In contrast, mechanism (iii) operates in all fish populations, but typically, mechanism (iii) results in relatively modest sex differences, with mature males only between 15 and 35% higher in PCB concentration than mature females. In summary, the study of sex differences in PCB concentrations of fish has led to insights into fish behaviour and fish physiology.

  19. Organochlorine pesticides and polychlorinated biphenyls in California sea lions

    Energy Technology Data Exchange (ETDEWEB)

    Kannan, K.; Kajiwara, N.; Le Boeuf, B.J.; Tanabe, S

    2004-10-01

    Concentrations of polychlorinated biphenyls (PCBs), DDTs, chlordanes, HCHs, hexachlorobenzene (HCB), dieldrin, heptachlor epoxide, tris(4-chlorophenyl)methane (TCPMe), and tris(4-chlorophenyl)methanol (TCPMOH) were measured in the blubber of California sea lions (Zalophus californianus) collected in 2000. DDTs were the most predominant contaminants, followed by PCBs, chlordanes, TCPMe, HCHs, TCPMOH, dieldrin, and heptachlor epoxide. Concentrations of PCBs and DDTs varied from a few {mu}g/g to several hundreds of {mu}g/g on a lipid weight basis. Concentrations of DDTs have declined by an order of magnitude over the last three decades in California sea lions; nevertheless, the measured concentrations of PCBs and DDTs in California sea lions are still some of the highest values reported for marine mammals in recent years. Concentrations of organochlorines were highly correlated with one another. Concentrations of PCBs and DDTs in the blubber of gray whale, humpback whale, northern elephant seal, and harbor seal, and in the adipose fat of sea otter, were lower than the levels found in California sea lions, and were in the range of a few to several {mu}g/g on a lipid weight basis.

  20. Prenatal exposure to polychlorinated biphenyls: a neuropsychologic analysis.

    Science.gov (United States)

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

    2009-01-01

    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. 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. 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. 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. 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.

  1. Isolation and identification of aerobic polychlorinated biphenyls degrading bacteria

    Directory of Open Access Journals (Sweden)

    Bibi Fatemeh Nabavi

    2013-01-01

    Full Text Available Aims: The purpose of this study was to isolate and identify aerobic polychlorinated biphenyls (PCBs degrading bacteria. Materials and Methods: This study was performed in lab scale aerobic sequencing batch biofilm reactor. Polyurethane foams were used as bio-carrier and synthetic wastewater was prepared with PCBs in transformer oil as the main substrate (20-700 μg/l and acetone as a solvent for PCBs as well as microelements. After achieving to adequate microbial population and acclimation of microorganisms to PCB compounds with high efficiency of PCB removal, identification of degrading microbial species was performed by 16s rRNA gene sequencing of isolated bacteria. Results: Gene sequencing results of the isolated bacteria showed that Rhodococcus spp., Pseudomonas spp., Pseudoxanthomonas spp., Agromyces spp., and Brevibacillus spp. were dominant PCB-degrading bacteria. Conclusion: PCB compounds can be degraded by some microorganisms under aerobic or anaerobic conditions or at least be reduced to low chlorinated congeners, despite their chemical stability and toxicity. Based on the results of the study, five bacterial species capable of degrading PCBs in transformer oil have been identified.

  2. Binding properties of halogenated biphenyls to cells and macromolecules

    International Nuclear Information System (INIS)

    Pepe, M.G.

    1982-01-01

    The interaction of polychlorinated biphenyls (PCB) with serum proteins may help explain the cellular incorporation of PCB as the effect of PCB on thyroid hormone function. PCB reduces serum thyroxine and triiodothyronine levels in rats; the mechanism for this effect is unknown. The initial distribution of PCB from blood to tissue is rapid and depends on blood perfusion and tissue affinity; however, the translocation of unmetabolized PCB from its initial storage sites to adipose tissue may depend on serum and cellular protein interactions. Therefore, the ability of PCB to displace triiodothyronine binding to albumin and antibodies, as well as the effect of binding to serum proteins as a mechanism for cellular incorporation was measured. PCB binding to albumin showed both high and low affinity binding sites. This binding was able to prevent triiodothyronine binding to albumin. The distribution of PCB inserum showed that lipoproteins contained 94% of the total 14 C PCB added, while 5% of the 14 C PCB was bound to albumin. The in vitro binding of 14 C PCB to serum obtained from rats pretreated with PCB in their diets for 6 months showed a significant decrease (p 14 C PCB was higher (p < 0.05) in liver, adrenal and adipose cells than pituitary and thyroid cells

  3. Organochlorine pesticides and polychlorinated biphenyls in California sea lions

    International Nuclear Information System (INIS)

    Kannan, K.; Kajiwara, N.; Le Boeuf, B.J.; Tanabe, S.

    2004-01-01

    Concentrations of polychlorinated biphenyls (PCBs), DDTs, chlordanes, HCHs, hexachlorobenzene (HCB), dieldrin, heptachlor epoxide, tris(4-chlorophenyl)methane (TCPMe), and tris(4-chlorophenyl)methanol (TCPMOH) were measured in the blubber of California sea lions (Zalophus californianus) collected in 2000. DDTs were the most predominant contaminants, followed by PCBs, chlordanes, TCPMe, HCHs, TCPMOH, dieldrin, and heptachlor epoxide. Concentrations of PCBs and DDTs varied from a few μg/g to several hundreds of μg/g on a lipid weight basis. Concentrations of DDTs have declined by an order of magnitude over the last three decades in California sea lions; nevertheless, the measured concentrations of PCBs and DDTs in California sea lions are still some of the highest values reported for marine mammals in recent years. Concentrations of organochlorines were highly correlated with one another. Concentrations of PCBs and DDTs in the blubber of gray whale, humpback whale, northern elephant seal, and harbor seal, and in the adipose fat of sea otter, were lower than the levels found in California sea lions, and were in the range of a few to several μg/g on a lipid weight basis

  4. Mixtures Estimation and Applications

    CERN Document Server

    Mengersen, Kerrie; Titterington, Mike

    2011-01-01

    This book uses the EM (expectation maximization) algorithm to simultaneously estimate the missing data and unknown parameter(s) associated with a data set. The parameters describe the component distributions of the mixture; the distributions may be continuous or discrete. The editors provide a complete account of the applications, mathematical structure and statistical analysis of finite mixture distributions along with MCMC computational methods, together with a range of detailed discussions covering the applications of the methods and features chapters from the leading experts on the subject

  5. Working out microsyntheses for different chlorinated biphenyls and preparation of 2,2'-dichlorobiphenyl-14C and 2,4'-dichlorobiphenyl-14C

    International Nuclear Information System (INIS)

    Geuenich, H.H.

    1972-01-01

    The microsyntheses for the preparation of chlorated biphenyls starting with benzene were worked out. 2,2'-dichlorobiphenyl- 14 C and 2,4'-dichlorobiphenyl- 14 C were prepared. 42 mCi benzene- 14 C were converted into nitrobenzene with nitrating acid, which was reduced to aniline by tin(II) chloride/hydrochloric acid. Following the acetylation of aniline with acetic anhydride, it was monochlorated in glacial acetic acid with chloride of lime, and the chlorination mixture was chromatographically separated in columns. 5.8 mCi o'-chloroanaline were diazotized and converted in ammoniacal copper(I) salt solution. 2 μCi 2,2'-dichlorobiphenyl were obtained. (orig./LH) [de

  6. Detection of polychlorinated biphenyls in transformer oils in Vietnam by multiphoton ionization mass spectrometry using a far-ultraviolet femtosecond laser as an ionization source.

    Science.gov (United States)

    Duong, Vu Thi Thuy; Duong, Vu; Lien, Nghiem Thi Ha; Imasaka, Tomoko; Tang, Yuanyuan; Shibuta, Shinpei; Hamachi, Akifumi; Hoa, Do Quang; Imasaka, Totaro

    2016-03-01

    Polychlorinated biphenyls (PCBs) in transformer and food oils were measured using gas chromatography combined with multiphoton ionization mass spectroscopy. An ultrashort laser pulse emitting in the far-ultraviolet region was utilized for efficient ionization of the analytes. Numerous signal peaks were clearly observed for a standard sample mixture of PCBs when the third and fourth harmonic emissions (267 and 200nm) of a femtosecond Ti:sapphire laser (800nm) were employed. The signal intensities were found to be greater when measured at 200nm compared with those measured at 267nm, providing lower detection limits especially for highly chlorinated PCBs at shorter wavelengths. After simple pretreatment using disposable columns, PCB congeners were measured and found to be present in the transformer oils used in Vietnam. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. I-optimal mixture designs

    OpenAIRE

    GOOS, Peter; JONES, Bradley; SYAFITRI, Utami

    2013-01-01

    In mixture experiments, the factors under study are proportions of the ingredients of a mixture. The special nature of the factors in a mixture experiment necessitates specific types of regression models, and specific types of experimental designs. Although mixture experiments usually are intended to predict the response(s) for all possible formulations of the mixture and to identify optimal proportions for each of the ingredients, little research has been done concerning their I-optimal desi...

  8. Mixtures and interactions

    NARCIS (Netherlands)

    Groten, J.P.

    2000-01-01

    Drinking water can be considered as a complex mixture that consists of tens, hundreds or thousands of chemicals of which the composition is qualitatively and quantitatively not fully known. From a public health point of view it is most relevant to answer the question of whether chemicals in drinking

  9. Isolation and characterization of a novel polychlorinated biphenyl-degrading bacterium, Paenibacillus sp. KBC101

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, M.; Ezaki, S.; Suzuki, N.; Kurane, R. [Kubota Corporation, Ryuugasaki City (Japan). Biotechnology Research Centre

    2005-07-01

    The biphenyl-utilizing bacterial strain KBC101 has been newly isolated from soil. Biphenyl-grown cells of KBC101 efficiently degraded di- to nonachlorobiphenyls. The isolate was identified as Paenibacillus sp. with respect to its 16S rDNA sequence and fatty acid profiles, as well as various biological and physiological characteristics. In the case of highly chlorinated biphenyl (polychlorinated biphenyl; PCB) congeners, the degradation activities of this strain were superior to those of the previously reported strong PCB degrader, Rhodococcus sp. RHA1. Recalcitrant coplanar PCBs, such as 3,4,3',4'-CB, were also efficiently degraded by strain KBC101 cells. This is the first report of a representative of the genus Paenibacillus capable of degrading PCBs. In addition to growth of biphenyl, strain KBC101 could grow on dibenzofuran, xanthene, benzophenone, anthrone, phenanthrene, napthalene, fluorene, fluoranthene, and chrysene as sole sources of carbon and energy. Paenibacillus sp. strain KBC101 presented heterogeneous degradation profiles toward various aromatic compounds. (orig.)

  10. Use of plant and earthworm bioassays to evaluate remediation of soil from a site contaminated with polychlorinated biphenyls

    Energy Technology Data Exchange (ETDEWEB)

    Meier, J.R.; Chang, L.W.; Meckes, M.C.; Smith, M.K. [Environmental Protection Agency, Cincinnati, OH (United States); Jacobs, S. [DynCorp, Cincinnati, OH (United States); Torsella, J. [Oak Ridge Inst. of Science and Education, Cincinnati, OH (United States)

    1997-05-01

    Soil from a site heavily contaminated with polychlorinated biphenyls (PCBs) was treated with a pilot-scale, solvent extraction technology. Bioassays in earthworms and plants were used to examine the efficacy of the remediation process for reducing the toxicity of the soil. The earthworm toxicity bioassays were the 14-d survival test and 21-d reproduction test, using Lumbricus terrestris and Eisenia fetida andrei. The plant bioassays included phytotoxicity tests for seed germination and root elongation in lettuce and oats, and a genotoxicity test (anaphase aberrations) in Allium cepa (common onion). Although the PCB content of the soil was reduced by 99% (below the remediation goal), toxicity to earthworm reproduction remained essentially unchanged following remediation. Furthermore, phytotoxicity and genotoxicity were higher for the remediated soil compared to the untreated soil. The toxicity remaining after treatment appeared to be due to residual solvent introduced during the remediation process, and/or to heavy metals or other inorganic contaminants not removed by the treatment. Mixture studies involving isopropanol and known toxicants indicated possible synergistic effects of the extraction solvent and soil contaminants. The toxicity in plants was essentially eliminated by a postremediation, water-rinsing step. These results demonstrate a need for including toxicity measurements in the evaluation of technologies used in hazardous waste site remediations, and illustrate the potential value of such measurements for making modifications to remediation processes.

  11. Assessment of the Polychlorinated Biphenyl (PCB Occurrence in Copper Sulfates and the Influential Role of PCB Levels on Grapes.

    Directory of Open Access Journals (Sweden)

    Xiaomin Li

    Full Text Available Copper sulfates (CuSO4 are widely used as the primary component of fungicides in the grape industry. The agricultural-grade CuSO4 that we collected from Chinese nationwide markets were found to be contaminated by polychlorinated dibenzo-p-dioxins and dibenzofurans and high levels of polychlorinated biphenyls (Σ19PCBs: 0.32~9.51 ng/g. In the following research, we studied the impact of CuSO4 application on PCB levels in grape products through a field experiment, and conducted a national survey to speculate the role that CuSO4 played on the occurrence of PCB in grapes. In the field experiment, an obvious increase of PCBs in grape leaves (from 174 to 250 pg/g fw was observed after Bordeaux mixture (the main component of which is CuSO4 application. As to the main PCB congener in CuSO4, the most toxic CB 126 (toxic equivalency factor = 0.1 also increased in grape peels (from 1.66 to 2.93 pg/g fw after pesticide spray. Both the correlation study and the principal component analysis indicated that environmental factors were dominant PCB contributors to grapes, and grapes from e-waste dismantling area containing the highest PCBs also proved the notion. It is worth noting that this report describes the first research examining PCBs in CuSO4 and its influence on agricultural products to date.

  12. Chemical contaminants on DOE lands and selection of contaminant mixtures for subsurface science research

    Energy Technology Data Exchange (ETDEWEB)

    Riley, R.G.; Zachara, J.M. [Pacific Northwest Lab., Richland, WA (United States)

    1992-04-01

    This report identifies individual contaminants and contaminant mixtures that have been measured in the ground at 91 waste sites at 18 US Department of Energy (DOE) facilities within the weapons complex. The inventory of chemicals and mixtures was used to identify generic chemical mixtures to be used by DOE`s Subsurface Science Program in basic research on the subsurface geochemical and microbiological behavior of mixed contaminants (DOE 1990a and b). The generic mixtures contain specific radionuclides, metals, organic ligands, organic solvents, fuel hydrocarbons, and polychlorinated biphenyls (PCBs) in various binary and ternary combinations. The mixtures are representative of in-ground contaminant associations at DOE facilities that are likely to exhibit complex geochemical behavior as a result of intercontaminant reactions and/or microbiologic activity stimulated by organic substances. Use of the generic mixtures will focus research on important mixed contaminants that are likely to be long-term problems at DOE sites and that will require cleanup or remediation. The report provides information on the frequency of associations among different chemicals and compound classes at DOE waste sites that require remediation.

  13. Differential effects of a complex organochlorine mixture on the proliferation of breast cancer cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Aube, Michel, E-mail: 4aubem@videotron.ca [Axe de recherche en sante des populations et environnementale, Centre de recherche du Centre hospitalier universitaire de Quebec and Universite Laval, 2875 Boulevard Laurier, Edifice Delta 2, bureau 600, Quebec, QC, Canada G1V 2M2 (Canada); Larochelle, Christian, E-mail: christian.larochelle@inspq.qc.ca [Axe de recherche en sante des populations et environnementale, Centre de recherche du Centre hospitalier universitaire de Quebec and Universite Laval, 2875 Boulevard Laurier, Edifice Delta 2, bureau 600, Quebec, QC, Canada G1V 2M2 (Canada); Ayotte, Pierre, E-mail: pierre.ayotte@inspq.qc.ca [Axe de recherche en sante des populations et environnementale, Centre de recherche du Centre hospitalier universitaire de Quebec and Universite Laval, 2875 Boulevard Laurier, Edifice Delta 2, bureau 600, Quebec, QC, Canada G1V 2M2 (Canada); Laboratoire de Toxicologie, Institut national de sante publique du Quebec, 945 avenue Wolfe, Quebec, QC, Canada G1V 5B3 (Canada)

    2011-04-15

    Organochlorine compounds (OCs) are a group of persistent chemicals that accumulate in fatty tissues with age. Although OCs has been tested individually for their capacity to induce breast cancer cell proliferation, few studies examined the effect of complex mixtures that comprise compounds frequently detected in the serum of women. We constituted such an OC mixture containing 15 different components in environmentally relevant proportions and assessed its proliferative effects in four breast cancer cell lines (MCF-7, T47D, CAMA-1, MDAMB231) and in non-cancerous CV-1 cells. We also determined the capacity of the mixture to modulate cell cycle stage of breast cancer cells and to induce estrogenic and antiandrogenic effects using gene reporter assays. We observed that low concentrations of the mixture (100x10{sup 3} and 50x10{sup 3} dilutions) stimulated the proliferation of MCF-7 cells while higher concentrations (10x10{sup 3} and 5x10{sup 3} dilutions) had the opposite effect. In contrast, the mixture inhibited the proliferation of non-hormone-dependent cell lines. The mixture significantly increased the number of MCF-7 cells entering the S phase, an effect that was blocked by the antiestrogen ICI 182,780. Low concentrations of the mixture also caused an increase in CAMA-1 cell proliferation but only in the presence estradiol and dihydrotestosterone (p<0.05 at the 50x10{sup 3} dilution). DDT analogs and polychlorinated biphenyls all had the capacity to stimulate the proliferation of CAMA-1 cells in the presence of sex steroids. Reporter gene assays further revealed that the mixture and several of its constituents (DDT analogs, aldrin, dieldrin, {beta}-hexachlorocyclohexane, toxaphene) induced estrogenic effects, whereas the mixture and several components (DDT analogs, aldrin, dieldrin and PCBs) inhibited the androgen signaling pathway. Our results indicate that the complex OC mixture increases the proliferation of MCF-7 cells due to its estrogenic potential. The

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

    Energy Technology Data Exchange (ETDEWEB)

    Agudo, Antonio, E-mail: a.agudo@iconcologia.net [Unit of Nutrition, Environment, and Cancer, Cancer Epidemiology Research Program, Catalan Institute of Oncology (ICO), IDIBELL, Av. Gran Via no 199-203, 08907 L' Hospitalet de Llobregat (Spain); Goni, Fernando [Laboratorio de Salud Publica de Guipuzcoa, 20013 San Sebastian (Spain); CIBER Epidemiologia y Salud Publica (CIBERESP) (Spain); Etxeandia, Arsenio [Laboratorio de Salud Publica de Vizcaya, 48010 Bilbao (Spain); Vives, Asuncion [Laboratorio Unificado Donostia, Hospital N. S. Aranzazu, 20014 San Sebastian (Spain); Millan, Esmeralda [Departamento de Quimica Aplicada, Universidad del Pais Vasco, Facultad de Quimica, 20080 San Sebastian (Spain); Lopez, Raul [CIBER Epidemiologia y Salud Publica (CIBERESP) (Spain); Amiano, Pilar [CIBER Epidemiologia y Salud Publica (CIBERESP) (Spain); Direccion de Salud de Guipuzcoa, 20013 San Sebastian (Spain); Ardanaz, Eva; Barricarte, Aurelio [CIBER Epidemiologia y Salud Publica (CIBERESP) (Spain); Instituto de Salud Publica de Navarra, 31003 Pamplona (Spain); Dolores Chirlaque, M. [CIBER Epidemiologia y Salud Publica (CIBERESP) (Spain); Consejeria de Sanidad, 3008 Murcia (Spain); Dorronsoro, Miren [CIBER Epidemiologia y Salud Publica (CIBERESP) (Spain); Direccion de Salud de Guipuzcoa, 20013 San Sebastian (Spain); Jakszyn, Paula [Unit of Nutrition, Environment, and Cancer, Cancer Epidemiology Research Program, Catalan Institute of Oncology (ICO), IDIBELL, Av. Gran Via no 199-203, 08907 L' Hospitalet de Llobregat (Spain); Larranaga, Nerea [CIBER Epidemiologia y Salud Publica (CIBERESP) (Spain); Direccion de Salud de Guipuzcoa, 20013 San Sebastian (Spain); Martinez, Carmen [CIBER Epidemiologia y Salud Publica (CIBERESP) (Spain); Escuela Andaluza de Salud Publica, 18080 Granada (Spain); Navarro, Carmen [CIBER Epidemiologia y Salud Publica (CIBERESP) (Spain); Consejeria de Sanidad, 3008 Murcia (Spain); Rodriguez, Laudina [Consejeria de Salud y Servicios Sanitarios de Asturias, 33001 Oviedo (Spain); 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.

  15. Association between polychlorinated biphenyls and Parkinson's disease neuropathology.

    Science.gov (United States)

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

    2012-10-01

    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 laboratory studies

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

    Science.gov (United States)

    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

  17. Immunotoxicity Monitoring in a Population Exposed to Polychlorinated Biphenyls

    Directory of Open Access Journals (Sweden)

    Hajo Haase

    2016-03-01

    Full Text Available 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.

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

    International Nuclear Information System (INIS)

    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

    2009-01-01

    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 μg/l); the corresponding figures for PCB 153 were 186 ng/g lipids and 1.25 μg/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.

  19. Dechlorination of polychlorinated biphenyls by iron and its oxides.

    Science.gov (United States)

    Sun, Yifei; Liu, Xiaoyuan; Kainuma, Masashi; Wang, Wei; Takaoka, Masaki; Takeda, Nobuo

    2015-10-01

    The decomposition efficiency of polychlorinated biphenyls (PCBs) was determined using elemental iron (Fe) and three iron (hydr)oxides, i.e., α-Fe2O3, Fe3O4, and α-FeOOH, as catalysts. The experiments were performed using four distinct PCB congeners (PCB-209, PCB-153, and the coplanar PCB-167 and PCB-77) at temperatures ranging from 180 °C to 380 °C and under an inert, oxidizing or reducing atmosphere composed of N2, N2+O2, or N2+H2. From these three options N2 showed to provide the best reaction atmosphere. Among the iron compounds tested, Fe3O4 showed the highest activity for decomposing PCBs. The decomposition efficiencies of PCB-209, PCB-167, PCB-153, and PCB-77 by Fe3O4 in an N2 atmosphere at 230 °C were 88.5%, 82.5%, 69.9%, and 66.4%, respectively. Other inorganic chlorine (Cl) products which were measured by the amount of inorganic Cl ions represented 82.5% and 76.1% of the reaction products, showing that ring cleavage of PCBs was the main elimination process. Moreover, the dechlorination did not require a particular hydrogen donor. We used X-ray photoelectron spectroscopy to analyze the elemental distribution at the catalyst's surface. The O/Fe ratio influenced upon the decomposition efficiency of PCBs: the lower this ratio, the higher the decomposition efficiency. X-ray absorption near edge structure spectra showed that α-Fe2O3 effectively worked as a catalyst, while Fe3O4 and α-FeOOH were consumed as reactants, as their final state is different from their initial state. Finally, a decomposition pathway was postulated in which the Cl atoms in ortho-positions were more difficult to eliminate than those in the para- or meta-positions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Self-nanoemulsifying drug delivery system for enhanced bioavailability and improved hepatoprotective activity of biphenyl dimethyl dicarboxylate.

    Science.gov (United States)

    El-Laithy, Hanan M

    2008-07-01

    Biphenyl Dimethyl Dicarboxylate (BDD) is insoluble in aqueous solution and the bioavailability after oral administration is low. Self-nanoemulsifying drug delivery system (SNEDDS) containing BDD has been successfully prepared using carefully selected ingredients which are less affected by pH and ionic strength changes to improve its bioavailability. SNEDDS is an isotropic mixture of lipid, surfactant, and cosurfactant which are spontaneously emulsified in aqueous medium under gentle digestive motility in the gastrointestinal tract. Pseudo ternary phase diagrams composed of various excipients were plotted to identify self -nano -emulsifying area. Droplet size changes upon dilution with aqueous media and in vitro release of BDD from SNEDDS in 0.1N HCl and phosphate buffer (pH 7.4) were studied and compared with commercial chinese pilules and Pennel capsules. The hepatoprotective activity upon oral administration of SNEDDS against carbon tetrachloride-induced oxidative stress in albino rats was assessed by measuring biochemical parameters like serum glutamic oxalacetate transaminase (SGOT), serum glutamic pyruvate transaminase (SGPT) and lactate dehydrogenase (LDH). Results showed that using a proper ratio of Tween 80 to Transcutol as surfactant and co-surfactant respectively and Miglyol 812 as oil to surfactants mixture resulted in production of infinitely diluted formulations in nano droplet size range. BDD self nano emulsified formula composed of 20% Miglyol 812, 60% Tween 80 and 20% Transcutol released 99% of the drug very rapidly within 10-15 minutes regardless of the pH condition. The oral absorption and bioavailability of BDD self nano emulsified formula in albino rats were significantly enhanced (P<0.01) with an average improvement of 1.7 and 6-folds that of commercial chinese pilules and Pennel capsules respectively. This improvement was also confirmed histopathologically in chemically injured rats and by the significant decrease in elevated liver enzymes

  1. Spermaturia and serum hormone concentrations at the age of puberty in boys prenatally exposed to polychlorinated biphenyls

    DEFF Research Database (Denmark)

    Mol, Nanette M; Sørensen, Nicolina; Weihe, Pal

    2002-01-01

    To determine whether prenatal exposure to polychlorinated biphenyls (PCBs) with possible hormone-disrupting effects is capable of affecting sexual differentiation in boys at the age of puberty.......To determine whether prenatal exposure to polychlorinated biphenyls (PCBs) with possible hormone-disrupting effects is capable of affecting sexual differentiation in boys at the age of puberty....

  2. Molecular Descriptors Family on Structure Activity Relationships 6. Octanol-Water Partition Coefficient of Polychlorinated Biphenyls

    Directory of Open Access Journals (Sweden)

    Lorentz JÄNTSCHI

    2006-01-01

    Full Text Available Octanol-water partition coefficient of two hundred and six polychlorinated biphenyls was model by the use of an original method based on complex information obtained from compounds structure. The regression analysis shows that best results are obtained in four-varied model (r2 = 0.9168. The prediction ability of the model was studied through leave-one-out analysis (r2cv(loo = 0.9093 and in training and test sets analysis. Modeling the octanol-water partition coefficient of polychlorinated biphenyls by integration of complex structural information provide a stable and performing four-varied model, allowing us to make remarks about relationship between structure of polychlorinated biphenyls and associated octanol-water partition coefficients.

  3. Polychlorinated biphenyls as inducers of hepatic porphyria in Japanese quail, with special reference to δ-aminolevulinic acid synthetase activity, fluorescence, and residues in the liver

    NARCIS (Netherlands)

    Vos, J.G.; Strik, J.T.W.A.; Holsteyn, C.W.M. van; Pennings, J.H.

    1971-01-01

    Male Japanese quail were orally dosed, daily for 7 days, with 1000, 500, 250, 100, 50, and 0 mg PCB (Aroclor 1260) per kg body weight. The birds receiving 1000 mg/kg died. A dose-related increase in liver and liver: body weight ratio was found. Macroscopic and microscopic examination under

  4. Mixture based outlier filtration

    Czech Academy of Sciences Publication Activity Database

    Pecherková, Pavla; Nagy, Ivan

    2006-01-01

    Roč. 46, č. 2 (2006), s. 30-35 ISSN 1210-2709 R&D Projects: GA MŠk 1M0572; GA MDS 1F43A/003/120 Institutional research plan: CEZ:AV0Z10750506 Keywords : data filtration * system modelling * mixture models Subject RIV: BD - Theory of Information http://library.utia.cas.cz/prace/20060165.pdf

  5. Mixture for plugging absorption zones

    Energy Technology Data Exchange (ETDEWEB)

    Sitinkov, G V; Kovalenko, N G; Makarov, L V; Zinnatulchin, Ts Kh

    1981-01-17

    A mixture is proposed for plugging absorption zones. The mixture contains synthetic polymer and a solvent. So as to increase the penetrability of the mixture through a reduction in its viscosity and an increase in insulation properties, the compound contains either Capron or Neilon as the synthetic polyamide resin polmyer, and concentrated chloride as the solvent. The mixture is prepared in a special AzINMASh-30 unit (acid cart). After the mixture has been produced, it is injected into the borehole by means of an acid cart pump. So as to prevent coaggulation at the point when the mixture in injected into the stratum through tubes, the mixture is placed betwen chemically inert fluids, for example, a clay mortar. The inert and compressed fluids are injected by means of a cementing unit. The entire process of production and application of the mixture is simple and fully automated through the use of well-known equipment.

  6. Simultaneous decontamination of cross-polluted soils with heavy metals and PCBs using a nano-metallic Ca/CaO dispersion mixture.

    Science.gov (United States)

    Mallampati, Srinivasa Reddy; Mitoma, Yoshiharu; Okuda, Tetsuji; Sakita, Shogo; Simion, Cristian

    2014-01-01

    In the present work, we investigated the use of nano-metallic calcium (Ca) and calcium oxide (CaO) dispersion mixture for the simultaneous remediation of contaminated soils with both heavy metals (As, Cd, Cr, and Pb) and polychlorinated biphenyls (PCBs). Regardless of soil moisture content, nano-metallic Ca/CaO dispersion mixture achieved about 95-99% of heavy metal immobilization by a simple grinding process. During the same treatment, reasonable PCB hydrodechlorination efficiencies were obtained (up to 97%), though higher hydrodechlorination efficiency by preliminary drying of soil was observed.

  7. Separating Underdetermined Convolutive Speech Mixtures

    DEFF Research Database (Denmark)

    Pedersen, Michael Syskind; Wang, DeLiang; Larsen, Jan

    2006-01-01

    a method for underdetermined blind source separation of convolutive mixtures. The proposed framework is applicable for separation of instantaneous as well as convolutive speech mixtures. It is possible to iteratively extract each speech signal from the mixture by combining blind source separation...

  8. Mixtures of truncated basis functions

    DEFF Research Database (Denmark)

    Langseth, Helge; Nielsen, Thomas Dyhre; Rumí, Rafael

    2012-01-01

    In this paper we propose a framework, called mixtures of truncated basis functions (MoTBFs), for representing general hybrid Bayesian networks. The proposed framework generalizes both the mixture of truncated exponentials (MTEs) framework and the mixture of polynomials (MoPs) framework. Similar t...

  9. Foetal uptake of coplanar polychlorinated biphenyl (PCB) congeners in mice

    International Nuclear Information System (INIS)

    Darnerud, P.O.; Sinjari, T.; Joensson, C.J.

    1996-01-01

    Earlier studies have shown that the Ah-receptor binding polychlorinated biphenyl (PCB) congener 3,3',4,4'-tetrachlorobiphenyl (IUPAC number CB-77) accumulated as hydroxy and methylsulphone metabolites in late gestational mice foetuses. In the present paper the foetal accumulation potential in mice of other dioxin-like PCB congeners was studied: 3,3'4,4',4-pentachlorobiphenyl, 3,3'4,4'5,5'-hexachlorobiphenyl and 2,3,3',4,4'-pentachlorobiphenyl (IUPAC numbers CB-126, CB-169, CB-105, to some extent dioxin-like) were compared to results of CB-77 (all congeners 14 C-labelled and in equimolar doses (2.0 μmol/kg body wt.)). CB-77 resulted in the comparatively strongest foetal 14 C-accumulation, when measured in plasma or whole body homogenate four days after administration (day 17 of pregnancy); the plasma 14 C-values (calculated as pmol/g wet wt.) were 760, 130, 60 and 40 for CB-77, -126, 105 and -169, respectively, and the CB-77 derived radioactivity in the foetal compartment was 3.6% of administered dose (i.e. a considerable portion of the remaining maternal body radioactivity). Thin-layer chromatography (TLC) results, suggesting extensive CB-77 metabolism and foetal metabolite uptake, support earlier findings. The effects of CB-77 and CB-169 on foetal 7-ethoxyresorufin-O-deethylase (EROD) activities (day 17 of gestation; two days after 5 mg/kg body wt. dose (14.0-17.0 μmol/kg body wt.)) was about 20 times lower than of CB-126. In the dam, high radioactivity levels were observed int he liver and fat (highest concentrations found in CB-126 and CB-105, respectively). Strain comparison - foetal 14 C-uptake (four days after administration of CB-77) in C57BL mice was almost five times higher than in NMRI - may be correlated to earlier observed differences in EROD activities between these strains. The present results indicate that congener and strain differences exist regarding both foetal and maternal distribution patterns of coplanar PCB congeners and point out the

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

    International Nuclear Information System (INIS)

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

    2014-01-01

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Spector, June T., E-mail: spectj@uw.edu [Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, 4225 Roosevelt Way NE, Seattle, WA 98105 (United States); Department of Medicine, School of Medicine, University of Washington, Seattle, WA (United States); De Roos, Anneclaire J., E-mail: ajd335@drexel.edu [Epidemiology Program, Public Health Sciences Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue N, P.O. Box 19024, Seattle, WA 98109 (United States); Department of Epidemiology, School of Public Health, University of Washington, Seattle, WA (United States); Ulrich, Cornelia M., E-mail: neli.ulrich@nct-heidelberg.de [Department of Epidemiology, School of Public Health, University of Washington, Seattle, WA (United States); Cancer Prevention Program, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue N, P.O. Box 19024, Seattle, WA 98109 (United States); National Center for Tumor Diseases and German Cancer Research Center, Heidelberg (Germany); Sheppard, Lianne, E-mail: sheppard@uw.edu [Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, 4225 Roosevelt Way NE, Seattle, WA 98105 (United States); Department of Biostatistics, School of Public Health, University of Washington, Seattle, WA (United States); Sjoedin, Andreas, E-mail: asjodin@cdc.gov [National Center for Environmental Health, CDC, 4770 Buford Highway NE, Atlanta, GA 30341 (United States); Wener, Mark H., E-mail: wener@u.washington.edu [Department of Medicine, School of Medicine, University of Washington, Seattle, WA (United States); Wood, Brent, E-mail: woodbl@u.washington.edu [Department of Medicine, School of Medicine, University of Washington, Seattle, WA (United States); 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

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

    Science.gov (United States)

    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. Copyright © 2012. Published by Elsevier Ltd.

  13. Embryonic treatment with xenobiotics disrupts steroid hormone profiles in hatchling red-eared slider turtles (Trachemys scripta elegans).

    Science.gov (United States)

    Willingham, E; Rhen, T; Sakata, J T; Crews, D

    2000-01-01

    Many compounds in the environment capable of acting as endocrine disruptors have been assayed for their developmental effects on morphogenesis; however, few studies have addressed how such xenobiotics affect physiology. In the current study we examine the effects of three endocrine-disrupting compounds, chlordane, trans-nonachlor, and the polychlorinated biphenyl (PCB) mixture Aroclor 1242, on the steroid hormone concentrations of red-eared slider turtle (Trachemys scripta elegans) hatchlings treated in ovo. Basal steroid concentrations and steroid concentrations in response to follicle-stimulating hormone were examined in both male and female turtles treated with each of the three compounds. Treated male turtles exposed to Aroclor 1242 or chlordane exhibited significantly lower testosterone concentrations than controls, whereas chlordane-treated females had significantly lower progesterone, testosterone, and 5[alpha]-dihydrotestosterone concentrations relative to controls. The effects of these endocrine disruptors extend beyond embryonic development, altering sex-steroid physiology in exposed animals. Images Figure 1 Figure 2 PMID:10753091

  14. Prevalence Incidence Mixture Models

    Science.gov (United States)

    The R package and webtool fits Prevalence Incidence Mixture models to left-censored and irregularly interval-censored time to event data that is commonly found in screening cohorts assembled from electronic health records. Absolute and relative risk can be estimated for simple random sampling, and stratified sampling (the two approaches of superpopulation and a finite population are supported for target populations). Non-parametric (absolute risks only), semi-parametric, weakly-parametric (using B-splines), and some fully parametric (such as the logistic-Weibull) models are supported.

  15. Neurological condition in 18-month-old children perinatally exposed to polychlorinated biphenyls and dioxins

    NARCIS (Netherlands)

    Huisman, M; KoopmanEsseboom, C; vanderPaauw, CG; Tuinstra, LGMT; Fidler, [No Value; WeisglasKuperus, N; Sauer, PJJ; Boersma, ER; Touwen, BCL

    1995-01-01

    The neurological optimality of 418 Dutch children was evaluated at the age of 18 months, in order to determine whether prenatal and breast milk mediated exposure to polychlorinated biphenyls (PCBs) and dioxins affected neurological development, Half of the infants were breast-fed, the other half

  16. Polychlorinated biphenyl-induced alterations of thyroid hormone homeostasis and brain development in the rat

    NARCIS (Netherlands)

    Morse, D.C.

    1995-01-01

    Introduction

    The work described in this thesis was undertaken to gain insight in the processes involved in the developmental neurotoxicity of polychlorinated biphenyls. It has been previously hypothesized that the alteration of thyroid hormone status by PCBs may

  17. EFFECTS OF POLYCHLORINATED-BIPHENYLS (PCBS) AND DIOXINS ON GROWTH AND DEVELOPMENT

    NARCIS (Netherlands)

    SAUER, PJJ; HUISMAN, M; KOOPMANESSEBOOM, C; MORSE, DC; SMITSVANPROOIJE, AE; VANDEBERG, KJ; TUINSTRA, LGMT; VANDERPAAUW, CG; BOERSMA, ER; WEISGLASKUPERUS, N; LAMMERS, JHCM; KULIG, BM; BROUWER, A

    1994-01-01

    Polychlorinated biphenyls (PCBs) and dioxins are potentially toxic compounds which occur widely in the environment. Their effects on the growth and development of infants at the levels currently found in highly industrialised western countries is not well known. This Dutch multicenter study,

  18. Preparation of plants containing bacterial enzyme for degradation of polychlorinated biphenyls

    Czech Academy of Sciences Publication Activity Database

    Francová, K.; Surá, M.; Macek, Tomáš; Szekeres, M.; Bancos, S.; Demnerová, K.; Sylvestre, M.; Macková, M.

    2003-01-01

    Roč. 12, č. 3 (2003), s. 309-313 ISSN 1018-4619 Institutional research plan: CEZ:AV0Z4055905 Keywords : transgenic plants * polychlorinated biphenyls * phytoremediation Subject RIV: DK - Soil Contamination ; De-contamination incl. Pesticides Impact factor: 0.325, year: 2003

  19. Polychlorinated biphenyls in adipose tissue, liver, and brain from nine stillborns of varying gestational ages

    NARCIS (Netherlands)

    Huisman, M; Muskiet, FAJ; Van Der Paauw, CG; Essed, CE; Boersma, ER

    We analyzed polychlorinated biphenyls (PCBs) in s.c. adipose tissue, liver, and brain of nine fetuses who died in utero. Their median (range) gestational ages and birth weights were 34 (17-40) wk and 2050 (162-3225) g. Three fetuses were small for gestational age. The levels of PCB congener nos.

  20. New Biochemical Pathway for Biphenyl Degradation in Plants: Structural, Mechanistic and Biotechnological Aspects

    International Nuclear Information System (INIS)

    Pacios, L. F.; Campos, V. M.; Merino, I.; Gomez, L.

    2009-01-01

    Polychlorinated biphenyls (PVBs) and other structurally-related xenobiotics are amongst the most relevant organic pollutants known today. while some bacterial species can metabolize PCBs, with varying efficiency, no catabolic pathways have yet been described in plants. This is so despite the great potential of (at least some) plant species for soil and groundwater decontamination, a technology known as phyto remediation. (Author)

  1. Predicting the bioaccumulation of polyaromatic hydrocarbons and polychlorinated biphenyls in benthic animals in sediments

    NARCIS (Netherlands)

    Tuikka, A. I.; Leppänen, M. T.; Akkanen, J.; Sormunen, A. J.; Leonards, P. E.G.; van Hattum, B.; van Vliet, L. A.; Brack, W.; Smedes, F.; Kukkonen, J. V.K.

    2016-01-01

    There were two main objectives in this study. The first was to compare the accuracy of different prediction methods for the chemical concentrations of polyaromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in the organism, based on the measured chemical concentrations existing in

  2. Effects of black carbon on bioturbination-induced benthic fluxes of polychlorinated biphenyls

    NARCIS (Netherlands)

    Koelmans, A.A.; Jonker, M.T.O.

    2011-01-01

    It is unknown whether carbonaceous geosorbents, such as black carbon (BC) affect bioturbation by benthic invertebrates, thereby possibly affecting sediment–water exchange of sediment-bound contaminants. Here, we assess the effects of oil soot on polychlorinated biphenyl (PCB) mass transfer from

  3. Contamination of free-range chicken eggs with dioxins and dioxin-like polychlorinated biphenyls

    NARCIS (Netherlands)

    Schoeters, G.; Hoogenboom, L.A.P.

    2006-01-01

    Dioxins and dioxin-like (DL) polychlorinated biphenyls (PCB) are persistent organic pollutants that enter the body mainly by food intake. A small margin exists between current exposure levels in the human population and the levels causing biological effects. Therefore, stringent control of

  4. Library of biphenyl privileged substructures using a safety-catch linker approach

    DEFF Research Database (Denmark)

    Severinsen, Rune; Bourne, Gregory T; Tran, Tran T

    2008-01-01

    A biphenyl privileged structure library containing three attachment points were synthesized using a catechol-based safety-catch linker strategy. The method requires the attachment of a bromo-acid to the linker, followed by a Pd-catalyzed Suzuki cross-coupling reaction. Further derivatization...

  5. ANALYSIS OF SOIL AND DUST SAMPLES FOR POLYCHLORINATED BIPHENYLS BY ENZYME LINKED IMMUNOSORBENT ASSAY (ELISA)

    Science.gov (United States)

    An inhibition enzyme-linked immunosorbent assay (ELISA) was used to determine polychlorinated biphenyls (PCBs) in house dust and soil. Soil and house dust samples were analyzed for PCB by both gas chromatography/electron capture detection (GC/ECD) and ELISA methods. A correlati...

  6. [Determination of biphenyl ether herbicides in water using HPLC with cloud-point extraction].

    Science.gov (United States)

    He, Cheng-Yan; Li, Yuan-Qian; Wang, Shen-Jiao; Ouyang, Hua-Xue; Zheng, Bo

    2010-01-01

    To determine residues of multiple biphenyl ether herbicides simultaneously in water using high performance liquid chromatography (HPLC) with cloud-point extraction. The residues of eight biphenyl ether herbicides (including bentazone, fomesafen, acifluorfen, aclonifen, bifenox, fluoroglycofenethy, nitrofen, oxyfluorfen) in water samples were extracted with cloud-point extraction of Triton X-114. The analytes were separated and determined using reverse phase HPLC with ultraviolet detector at 300 nm. Optimized conditions for the pretreatment of water samples and the parameters of chromatographic separation applied. There was a good linear correlation between the concentration and the peak area of the analytes in the range of 0.05-2.00 mg/L (r = 0.9991-0.9998). Except bentazone, the spiked recoveries of the biphenyl ether herbicides in the water samples ranged from 80.1% to 100.9%, with relative standard deviations ranging from 2.70% to 6.40%. The detection limit of the method ranged from 0.10 microg/L to 0.50 microg/L. The proposed method is simple, rapid and sensitive, and can meet the requirements of determination of multiple biphenyl ether herbicides simultaneously in natural waters.

  7. Allee effect in polar bears: A potential consequence of polychlorinated biphenyl contamination.

    Czech Academy of Sciences Publication Activity Database

    Pavlová, Viola; Nabe-Nielsen, J.; Dietz, R.; Sonne, C.; Grimm, V.

    2016-01-01

    Roč. 283, č. 1843 (2016), č. článku 20161883. ISSN 0962-8452 Institutional support: RVO:60077344 Keywords : allee effect * polychlorinated biphenyls * polar bears * male reproduction Subject RIV: EH - Ecology, Behaviour Impact factor: 4.940, year: 2016

  8. Uptake of polychlorinated biphenyls and organochlorine pesticides from soil and air into radishes (Raphanus sativus)

    DEFF Research Database (Denmark)

    Mikes, Ondrej; Cupr, P.; Trapp, Stefan

    2009-01-01

    Uptake of organochlorine pesticides and polychlorinated biphenyls from soil and air into radishes was measured at a heavily contaminated field site. The highest contaminant concentrations were found for DDT and its metabolites, and for beta-hexachlorocyclohexane. Bioconcentration factor (BCF, def...

  9. Separation of gas mixtures

    International Nuclear Information System (INIS)

    1981-01-01

    Apparatus is described for the separation of a gaseous plasma mixture into components in some of which the original concentration of a specific ion has been greatly increased or decreased, comprising: a source for converting the gaseous mixture into a train of plasma packets; an open-ended vessel with a main section and at least one branch section, adapted to enclose along predetermined tracks the original plasma packets in the main section, and the separated plasma components in the branch sections; drive means for generating travelling magnetic waves along the predetermined tracks with the magnetic flux vector of the waves transverse to each of the tracks; and means for maintaining phase coherence between the plasma packets and the magnetic waves at a value needed for accelerating the components of the packets to different velocities and in such different directions that the plasma of each packet is divided into distinctly separate packets in some of which the original concentration of a specific ion has been greatly increased or decreased, and which plasma packets are collected from the branch sections of the vessels. (author)

  10. Research of Deformation of Clay Soil Mixtures Mixtures

    OpenAIRE

    Romas Girkontas; Tadas Tamošiūnas; Andrius Savickas

    2014-01-01

    The aim of this article is to determine clay soils and clay soils mixtures deformations during drying. Experiments consisted from: a) clay and clay mixtures bridges (height ~ 0,30 m, span ~ 1,00 m); b) tiles of clay and clay, sand and straw (height, length, wide); c) cylinders of clay; clay and straw; clay, straw and sand (diameter; height). According to the findings recommendations for clay and clay mixtures drying technology application were presented. During the experiment clay bridge bear...

  11. Mutagenicity of complex mixtures

    International Nuclear Information System (INIS)

    Pelroy, R.A.

    1985-01-01

    The effect of coal-derived complex chemical mixtures on the mutagenicity of 6-aminochrysene (6-AC) was determined with Salmonella typhimurium TA98. Previous results suggested that the mutagenic potency of 6-AC for TA98 in the standard microsomal activation (Ames) assay increased if it was presented to the cells mixed with high-boiling coal liquids (CL) from the solvent refined coal (SRC) process. In this year's work, the apparent mutational synergism of CL and 6-AC was independently verified in a fluctuation bioassay which allowed quantitation of mutational frequencies and cell viability. The results of this assay system were similar to those in the Ames assay. Moreover, the fluctation assay revealed that mutagenesis and cellular toxicity induced by 6-AC were both strongly enhanced if 6-AC was presented to the cells mixed in a high-boiling CL. 4 figures

  12. Hybrid pseudomonads engineered by two-step homologous recombination acquire novel degradation abilities toward aromatics and polychlorinated biphenyls

    Energy Technology Data Exchange (ETDEWEB)

    Suenaga, Hikaru [National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba (Japan). Bioproduction Research Inst.; Nonaka, Kazuhiko; Goto, Masatoshi [Kyushu Univ., Fukuoka (Japan). Dept. of Bioscience and Biotechnology; Fujihara, Hidehiko; Furukawa, Kensuke [Beppu Univ. (Japan). Dept. of Fermentation and Food Science

    2010-10-15

    Pseudomonas pseudoalcaligenes KF707 possesses a chromosomally encoded bph gene cluster responsible for the catabolism of biphenyl and polychlorinated biphenyls. Previously, we constructed chimeric versions of the bphA1 gene, which encodes a large subunit of biphenyl dioxygenase, by using DNA shuffling between bphA1 genes from P. pseudoalcaligenes KF707 and Burkholderia xenovorans LB400. In this study, we demonstrate replacement of the bphA1 gene with chimeric bphA1 sequence within the chromosomal bph gene cluster by two-step homologous recombination. Notably, some of the hybrid strains acquired enhanced and/or expanded degradation capabilities for specific aromatic compounds, including single aromatic hydrocarbons and polychlorinated biphenyls. (orig.)

  13. Proof of concept for the use of macroinvertebrates as indicators of polychlorinated biphenyls (PCB) contamination in Lake Hartwell

    Science.gov (United States)

    The U.S. Environmental Protection Agency (EPA) has been conducting research to develop methods and tools for the evaluation of monitored natural recovery (MNR) of sediments contaminated with polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and other lega...

  14. Evaluating Chemical Reactivity And Mechanical Stability Of Nano Palladized Iron Embedded In Activated Carbon On Dechlorination Of Polychlorinated Biphenyls

    Science.gov (United States)

    Remediation of contaminated sites with hydrophobic organic compounds such as polychlorinated biphenyls (PCBs) remains a scientific and technical challenge. The high stability, low aqueous solubility, and high organic affinity of PCBs make them difficult to treat. Many physical,...

  15. Complex mixtures biostudies

    International Nuclear Information System (INIS)

    Springer, D.L.

    1987-01-01

    The objective of the project is to identify potential adverse biological activities associated with human exposures to complex organic mixtures (COM) from energy-related industries. Studies to identify the influence of chemical class fractions from a COM on the initiating activity of a known carcinogen, benzo(a)pyrene (BaP), demonstrated that the polycyclic aromatic hydrocarbons (PAH) and nitrogen-containing polycyclic aromatic compound (NPAC) fractions were the most effective inhibitors of initiation. In an effort to determine the contribution of BaP to the initiating activity of the COM, binding of radiolabeled BaP to mouse skin DNA was measured. Results indicated that binding of BaP to DNA decreased in the presence of the COM so that at initiating COM doses, BaP binding was near the limit detection. Addition of unlabeled BaP to the COM at an amount similar to that originally present in the COM did not significantly increase the binding. Studies to determine the rates of disappearance of carcinogenic PAH from the site of application on the skin indicated that half-lives for PAH differed by a factor of about 2. Analytical methods developed to identify PAH from COM which covalently bind to DNA demonstrated that the lower level of detection is approximately 200 picograms. Developmental studies demonstrated that both pregnant rats and mice treated dermally with a high-boiling COM developed fetuses with major malformations including cleft palate, small lungs, edema, and sagittal suture hemorrhages. 3 figures, 5 tables

  16. The effects of pruning and nodal adventitious roots on polychlorinated biphenyl uptake by Cucurbita pepo grown in field conditions

    Energy Technology Data Exchange (ETDEWEB)

    Low, Jennifer E.; Whitfield Aslund, Melissa L. [Department of Chemistry and Chemical Engineering, Royal Military College of Canada, PO Box 17000 Station Forces, Kingston, ON, K7K 7B4 (Canada); Rutter, Allison [School of Environmental Studies, Rm 0626 Biosciences Complex, Queen' s University, 116 Barrie St., Kingston, ON, K7L 3N6 (Canada); Zeeb, Barbara A., E-mail: zeeb-b@rmc.ca [Department of Chemistry and Chemical Engineering, Royal Military College of Canada, PO Box 17000 Station Forces, Kingston, ON, K7K 7B4 (Canada)

    2011-03-15

    Two cultivation techniques (i-pruning and ii-nodal adventitious root encouragement) were investigated for their ability to increase PCB phytoextraction by Cucurbita pepo ssp pepo cv. Howden (pumpkin) plants in situ at a contaminated industrial site in Ontario (Aroclor 1248, mean soil [PCB] = 5.6 {mu}g g{sup -1}). Pruning was implemented to increase plant biomass close to the root where PCB concentration is known to be highest. This treatment was found to have no effect on final shoot biomass or PCB concentration. However, material pruned from the plant is not included in the final shoot biomass. The encouragement of nodal adventitious roots at stem nodes did significantly increase the PCB concentration in the primary stem, while not affecting shoot biomass. Both techniques are easily applied cultivation practices that may be implemented to decrease phytoextraction treatment time. - Research highlights: > Presence of nodal adventitious roots do increase phytoextraction efficiency. > Pruning may increase the biomass of pumpkin plants during phytoextraction. > [Aroclor 1248] decreases in plant tissue with increasing distance from the root. - The application of cultivation practices (pruning and nodal adventitious root encouragement) increases phytoextraction of PCBs in C. pepo.

  17. The effects of pruning and nodal adventitious roots on polychlorinated biphenyl uptake by Cucurbita pepo grown in field conditions

    International Nuclear Information System (INIS)

    Low, Jennifer E.; Whitfield Aslund, Melissa L.; Rutter, Allison; Zeeb, Barbara A.

    2011-01-01

    Two cultivation techniques (i-pruning and ii-nodal adventitious root encouragement) were investigated for their ability to increase PCB phytoextraction by Cucurbita pepo ssp pepo cv. Howden (pumpkin) plants in situ at a contaminated industrial site in Ontario (Aroclor 1248, mean soil [PCB] = 5.6 μg g -1 ). Pruning was implemented to increase plant biomass close to the root where PCB concentration is known to be highest. This treatment was found to have no effect on final shoot biomass or PCB concentration. However, material pruned from the plant is not included in the final shoot biomass. The encouragement of nodal adventitious roots at stem nodes did significantly increase the PCB concentration in the primary stem, while not affecting shoot biomass. Both techniques are easily applied cultivation practices that may be implemented to decrease phytoextraction treatment time. - Research highlights: → Presence of nodal adventitious roots do increase phytoextraction efficiency. → Pruning may increase the biomass of pumpkin plants during phytoextraction. → [Aroclor 1248] decreases in plant tissue with increasing distance from the root. - The application of cultivation practices (pruning and nodal adventitious root encouragement) increases phytoextraction of PCBs in C. pepo.

  18. Immunotoxicity of environmentally relevant mixtures of polychlorinated aromatic hydrocarbons with methyl mercury on rat lymphocytes in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Omara, F.O.; Brochu, C.; Flipo, D.; Denizeau, F.; Fournier, M. [Univ. of Quebec, Montreal, Quebec (Canada)

    1997-03-01

    The immunosuppressive effects of methyl mercury (MHg), polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and dibenzofurans (PCDFs) are well established at higher exposure levels but unclear at low exposure levels. The authors exposed Fischer 344 rat splenocytes, thymocytes, and peripheral blood lymphocytes in vitro for 72 h to MHg of three PCDDs and two PCDFs PCB mixtures, or combinations of MHg/PCB/PCDD/PCDF mixtures Mitogenic responses of lymphocytes to concanavalin A, phytohemagglutinin, or lipopolysaccharide/dextran sulfate were determined by {sup 3}H-thymidine uptake; cytotoxicity and intracellular Ca{sup 2+} were determined by flow cytometry. Methylmercury mixtures with 2 {micro}g/ml MHg decreased the viability of splenocytes to 57 and 40% at 4 and 24 h, respectively. Basal intracellular calcium ion levels were unaffected by the treatments. Methylmercury suppressed the responses of lymphocytes to T and B cell mitogens. All combinations of MHg/PCB/PCDD/PCDF mixtures decreased mitogenic responses to levels similar to those to MHg alone. In contrast, PCB and PCDD/PCDF mixtures did not suppress but augmented responses of splenocytes and peripheral blood lymphocytes to T cell mitogens. Overall, no interactive toxicity was observed with MHg/PCB/PCDD/PCDF mixtures on cytotoxicity and lymphocyte mitogenic responses. Therefore, MHg may pose a greater threat than organochlorines to the mammalian immune system.

  19. Structurally simplified biphenyl combretastatin A4 derivatives retain in vitro anti-cancer activity dependent on mitotic arrest

    Science.gov (United States)

    Tarade, Daniel; Ma, Dennis; Pignanelli, Christopher; Mansour, Fadi; Simard, Daniel; van den Berg, Sean; Gauld, James; McNulty, James; Pandey, Siyaram

    2017-01-01

    The cis-stilbene, combretastatin A4 (CA4), is a potent microtubule targeting and vascular damaging agent. Despite promising results at the pre-clinical level and extensive clinical evaluation, CA4 has yet to be approved for therapeutic use. One impediment to the development of CA4 is an inherent conformational instability about the ethylene linker, which joins two aromatic rings. We have previously published preliminary data regarding structurally simplified biphenyl derivatives of CA4, lacking an ethylene linker, which retain anti-proliferative and pro-apoptotic activity, albeit at higher doses. Our current study provides a more comprehensive evaluation regarding the anti-proliferative and pro-apoptotic properties of biphenyl CA4 derivatives in both 2D and 3D cancerous and non-cancerous cell models. Computational analysis has revealed that cytotoxicity of CA4 and biphenyl analogues correlates with predicted tubulin affinity. Additional mechanistic evaluation of the biphenyl derivatives found that their anti-cancer activity is dependent on prolonged mitotic arrest, in a similar manner to CA4. Lastly, we have shown that cancer cells deficient in the extrinsic pathway of apoptosis experience delayed cell death following treatment with CA4 or analogues. Biphenyl derivatives of CA4 represent structurally simplified analogues of CA4, which retain a similar mechanism of action. The biphenyl analogues warrant in vivo examination to evaluate their potential as vascular damaging agents. PMID:28253265

  20. Structurally simplified biphenyl combretastatin A4 derivatives retain in vitro anti-cancer activity dependent on mitotic arrest.

    Directory of Open Access Journals (Sweden)

    Daniel Tarade

    Full Text Available The cis-stilbene, combretastatin A4 (CA4, is a potent microtubule targeting and vascular damaging agent. Despite promising results at the pre-clinical level and extensive clinical evaluation, CA4 has yet to be approved for therapeutic use. One impediment to the development of CA4 is an inherent conformational instability about the ethylene linker, which joins two aromatic rings. We have previously published preliminary data regarding structurally simplified biphenyl derivatives of CA4, lacking an ethylene linker, which retain anti-proliferative and pro-apoptotic activity, albeit at higher doses. Our current study provides a more comprehensive evaluation regarding the anti-proliferative and pro-apoptotic properties of biphenyl CA4 derivatives in both 2D and 3D cancerous and non-cancerous cell models. Computational analysis has revealed that cytotoxicity of CA4 and biphenyl analogues correlates with predicted tubulin affinity. Additional mechanistic evaluation of the biphenyl derivatives found that their anti-cancer activity is dependent on prolonged mitotic arrest, in a similar manner to CA4. Lastly, we have shown that cancer cells deficient in the extrinsic pathway of apoptosis experience delayed cell death following treatment with CA4 or analogues. Biphenyl derivatives of CA4 represent structurally simplified analogues of CA4, which retain a similar mechanism of action. The biphenyl analogues warrant in vivo examination to evaluate their potential as vascular damaging agents.

  1. Component effects in mixture experiments

    International Nuclear Information System (INIS)

    Piepel, G.F.

    1980-01-01

    In a mixture experiment, the response to a mixture of q components is a function of the proportions x 1 , x 2 , ..., x/sub q/ of components in the mixture. Experimental regions for mixture experiments are often defined by constraints on the proportions of the components forming the mixture. The usual (orthogonal direction) definition of a factor effect does not apply because of the dependence imposed by the mixture restriction, /sup q/Σ/sub i=1/ x/sub i/ = 1. A direction within the experimental region in which to compute a mixture component effect is presented and compared to previously suggested directions. This new direction has none of the inadequacies or errors of previous suggestions while having a more meaningful interpretation. The distinction between partial and total effects is made. The uses of partial and total effects (computed using the new direction) in modification and interpretation of mixture response prediction equations are considered. The suggestions of the paper are illustrated in an example from a glass development study in a waste vitrification program. 5 figures, 3 tables

  2. Mixtures of skewed Kalman filters

    KAUST Repository

    Kim, Hyoungmoon; Ryu, Duchwan; Mallick, Bani K.; Genton, Marc G.

    2014-01-01

    Normal state-space models are prevalent, but to increase the applicability of the Kalman filter, we propose mixtures of skewed, and extended skewed, Kalman filters. To do so, the closed skew-normal distribution is extended to a scale mixture class

  3. Easy and flexible mixture distributions

    DEFF Research Database (Denmark)

    Fosgerau, Mogens; Mabit, Stefan L.

    2013-01-01

    We propose a method to generate flexible mixture distributions that are useful for estimating models such as the mixed logit model using simulation. The method is easy to implement, yet it can approximate essentially any mixture distribution. We test it with good results in a simulation study...

  4. Determination of vaporization enthalpies of polychlorinated biphenyls by correlation gas chromatography.

    Science.gov (United States)

    Puri, S; Chickos, J S; Welsh, W J

    2001-04-01

    The vaporization enthalpies of 16 polychlorinated biphenyls have been determined by correlation gas chromatography. This study was prompted by the realization that the vaporization enthalpy of the standard compounds used in previous studies, octadecane and eicosane, were values measured at 340 and 362 K, respectively, rather than at 298 K. Adjustment to 298 K amounts to a 7-8 kJ/mol increment in the values. With the inclusion of this adjustment, vaporization enthalpies evaluated by correlation gas chromatography are in good agreement with the values determined previously in the literature. The present results are based on the vaporization enthalpies of several standards whose values are well established in the literature. The standards include a variety of n-alkanes and various chlorinated hydrocarbons. The vaporization enthalpies of PCBs increased with the number of chlorine atoms and were found to be larger for meta- and para-substituted polychlorinated biphenyls.

  5. CLOSURE REPORT FOR CORRECTIVE ACTION UNIT 528: POLYCHLORINATED BIPHENYLS CONTAMINATION NEVADA TEST SITE, NEVADA

    Energy Technology Data Exchange (ETDEWEB)

    BECHTEL NEVADA

    2006-09-01

    This Closure Report (CR) describes the closure activities performed at CAU 528, Polychlorinated Biphenyls Contamination, as presented in the Nevada Division of Environmental Protection (NDEP)-approved Corrective Action Plan (CAP) (US. Department of Energy, National Nuclear Security Administration Nevada Site Office [NNSAINSO], 2005). The approved closure alternative was closure in place with administrative controls. This CR provides a summary of the completed closure activities, documentation of waste disposal, and analytical data to confirm that the remediation goals were met.

  6. Photoionization and Electron Transfer of Biphenyl within the Channels of Al-ZSM-5 Zeolites.

    Science.gov (United States)

    Gener, Isabelle; Buntinx, Guy; Brémard, Claude

    1999-06-14

    Evidence of the photogenerated long-lived biphenyl radical and a trapped electron in the void space of aluminated nonacidic ZSM-5 zeolites has been obtained from the time-resolved UV/Vis absorption, Raman scattering, and EPR spectra. The restoration of the ground states implicates the existence of long-lived positive holes in the framework. © 1999 WILEY-VCH Verlag GmbH, Weinheim, Fed. Rep. of Germany.

  7. Polychlorinated biphenyls and reproductive hormones in female polar bears at Svalbard.

    OpenAIRE

    Haave, Marte; Ropstad, Erik; Derocher, Andrew E; Lie, Elisabeth; Dahl, Ellen; Wiig, Øystein; Skaare, Janneche U; Jenssen, Bjørn Munro

    2003-01-01

    High concentrations of polychlorinated biphenyls (PCBs) in polar bears from Svalbard have increased concern for that population's reproductive health. We examined whether there were associations between the plasma concentrations of PCBs and reproductive hormones [progesterone (P4)] and 17 beta-estradiol (E2)] in free-living female polar bears from Svalbard. Concentrations of P4 depended on reproductive status, and concentrations were lowest in females with offspring--females with cubs and fem...

  8. Importance of Passive Diffusion in the Uptake of Polychlorinated Biphenyls by Phagotrophic Protozoa†

    OpenAIRE

    Kujawinski, Elizabeth B.; Farrington, John W.; Moffett, James W.

    2000-01-01

    Unicellular protozoan grazers represent a size class of organisms where a transition in the mechanism of chlorobiphenyl (CB) introduction, from diffusion through surface membranes to ingestion of contaminated prey, could occur. This study compares the relative importance of these two processes in the overall uptake of polychlorinated biphenyls by protists. Uptake rates and steady-state concentrations were compared in laboratory cultures of grazing and nongrazing protozoa. These experiments we...

  9. A new biphenyl derivative from the mangrove endophytic fungus Phomopsis longicolla HL-2232.

    Science.gov (United States)

    Li, Xiao-Bao; Chen, Guang-Ying; Liu, Rui-Jie; Zheng, Cai-Juan; Song, Xin-Ming; Han, Chang-Ri

    2017-10-01

    A new biphenyl derivative 5,5'-dimethoxybiphenyl-2,2'-diol (1), together with five known compounds (2-5), was isolated from the mangrove endophytic fungus Phomopsis longicolla HL-2232. The structures of these compounds were elucidated using comprehensive spectroscopic methods. The absolute configuration of 4 was determined by single-crystal X-ray diffraction for the first time. The inhibitory activities of all compounds against two Vibrio bacteria were evaluated.

  10. Metabolism of chlorobiphenyls by a variant biphenyl dioxygenase exhibiting enhanced activity toward dibenzofuran

    International Nuclear Information System (INIS)

    Viger, Jean-François; Mohammadi, Mahmood; Barriault, Diane; Sylvestre, Michel

    2012-01-01

    Highlights: ► Burkholderia xenovorans LB400 biphenyl dioxygenase (BphAE LB400 ) metabolizes PCBs. ► Asn338Gln/Leu409Phe double mutation speeds up electron transfer of enzyme reaction. ► We tested how the mutations affect the PCB-degrading abilities of BphAE LB400 variants. ► The same mutations also broaden the PCB substrate range of BphAE LB400 variants. -- Abstract: The biphenyl dioxygenase of Burkholderia xenovorans LB400 (BphAE LB400 ) catalyzes the dihydroxylation of biphenyl and of several polychlorinated biphenyls (PCBs) but it poorly oxidizes dibenzofuran. In this work we showed that BphAE RR41 , a variant which was previously found to metabolize dibenzofuran more efficiently than its parent BphAE LB400 , metabolized a broader range of PCBs than BphAE LB400 . Hence, BphAE RR41 was able to metabolize 2,6,2′,6′-, 3,4,3′,5′- and 2,4,3′,4′-tetrachlorobiphenyl that BphAE LB400 is unable to metabolize. BphAE RR41 was obtained by changing Thr335Phe336Asn338Ile341Leu409 of BphAE LB400 to Ala335Met336Gln338Val341Phe409. Site-directed mutagenesis was used to create combinations of each substitution, in order to assess their individual contributions. Data show that the same Asn338Glu/Leu409Phe substitution that enhanced the ability to metabolize dibenzofuran resulted in a broadening of the PCB substrates range of the enzyme. The role of these substitutions on regiospecificities toward selected PCBs is also discussed.

  11. Metabolism of chlorobiphenyls by a variant biphenyl dioxygenase exhibiting enhanced activity toward dibenzofuran

    Energy Technology Data Exchange (ETDEWEB)

    Viger, Jean-Francois; Mohammadi, Mahmood; Barriault, Diane [Institut National de la Recherche Scientifique, INRS-Institut Armand-Frappier, Laval, Quebec, Canada H4K 1C2 (Canada); Sylvestre, Michel, E-mail: Michel.Sylvestre@iaf.inrs.ca [Institut National de la Recherche Scientifique, INRS-Institut Armand-Frappier, Laval, Quebec, Canada H4K 1C2 (Canada)

    2012-03-09

    Highlights: Black-Right-Pointing-Pointer Burkholderia xenovorans LB400 biphenyl dioxygenase (BphAE{sub LB400}) metabolizes PCBs. Black-Right-Pointing-Pointer Asn338Gln/Leu409Phe double mutation speeds up electron transfer of enzyme reaction. Black-Right-Pointing-Pointer We tested how the mutations affect the PCB-degrading abilities of BphAE{sub LB400} variants. Black-Right-Pointing-Pointer The same mutations also broaden the PCB substrate range of BphAE{sub LB400} variants. -- Abstract: The biphenyl dioxygenase of Burkholderia xenovorans LB400 (BphAE{sub LB400}) catalyzes the dihydroxylation of biphenyl and of several polychlorinated biphenyls (PCBs) but it poorly oxidizes dibenzofuran. In this work we showed that BphAE{sub RR41}, a variant which was previously found to metabolize dibenzofuran more efficiently than its parent BphAE{sub LB400}, metabolized a broader range of PCBs than BphAE{sub LB400}. Hence, BphAE{sub RR41} was able to metabolize 2,6,2 Prime ,6 Prime -, 3,4,3 Prime ,5 Prime - and 2,4,3 Prime ,4 Prime -tetrachlorobiphenyl that BphAE{sub LB400} is unable to metabolize. BphAE{sub RR41} was obtained by changing Thr335Phe336Asn338Ile341Leu409 of BphAE{sub LB400} to Ala335Met336Gln338Val341Phe409. Site-directed mutagenesis was used to create combinations of each substitution, in order to assess their individual contributions. Data show that the same Asn338Glu/Leu409Phe substitution that enhanced the ability to metabolize dibenzofuran resulted in a broadening of the PCB substrates range of the enzyme. The role of these substitutions on regiospecificities toward selected PCBs is also discussed.

  12. Anaerobic degradation of Polychlorinated Biphenyls (PCBs) and Polychlorinated Biphenyls Ethers (PBDEs), and microbial community dynamics of electronic waste-contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Song, Mengke [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate University of Chinese Academy of Sciences, Beijing 100039 (China); Luo, Chunling, E-mail: clluo@gig.ac.cn [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Li, Fangbai [Guangdong Institute of Eco-environmental and Soil Sciences, Guangzhou 510650 (China); Jiang, Longfei [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); College of Life Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Wang, Yan [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Zhang, Dayi [Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ (United Kingdom); Zhang, Gan [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)

    2015-01-01

    Environmental contamination caused by electronic waste (e-waste) recycling is attracting increasing attention worldwide because of the threats posed to ecosystems and human safety. In the present study, we investigated the feasibility of in situ bioremediation of e-waste-contaminated soils. We found that, in the presence of lactate as an electron donor, higher halogenated congeners were converted to lower congeners via anaerobic halorespiration using ferrous ions in contaminated soil. The 16S rRNA gene sequences of terminal restriction fragments indicated that the three dominant strains were closely related to known dissimilatory iron-reducing bacteria (DIRB) and those able to perform dehalogenation upon respiration. The functional species performed the activities of ferrous oxidation to ferric ions and further ferrous reduction for dehalogenation. The present study links iron cycling to degradation of halogenated materials in natural e-waste-contaminated soil, and highlights the synergistic roles of soil bacteria and ferrous/ferric ion cycling in the dehalogenation of polychlorinated biphenyls (PCBs) and polybrominated biphenyl ethers (PBDEs). - Highlights: • The biodegradation PCBs and PBDEs in e-waste contaminated soils was studied. • DIRB and arylhalorespiring bacteria were responsive to dehalogenation respiration. • Soil bacteria and Fe ion cycling play synergistic roles in dehalogenation.

  13. A general mixture theory. I. Mixtures of spherical molecules

    Science.gov (United States)

    Hamad, Esam Z.

    1996-08-01

    We present a new general theory for obtaining mixture properties from the pure species equations of state. The theory addresses the composition and the unlike interactions dependence of mixture equation of state. The density expansion of the mixture equation gives the exact composition dependence of all virial coefficients. The theory introduces multiple-index parameters that can be calculated from binary unlike interaction parameters. In this first part of the work, details are presented for the first and second levels of approximations for spherical molecules. The second order model is simple and very accurate. It predicts the compressibility factor of additive hard spheres within simulation uncertainty (equimolar with size ratio of three). For nonadditive hard spheres, comparison with compressibility factor simulation data over a wide range of density, composition, and nonadditivity parameter, gave an average error of 2%. For mixtures of Lennard-Jones molecules, the model predictions are better than the Weeks-Chandler-Anderson perturbation theory.

  14. Parental exposure to natural mixtures of POPs reduced embryo production and altered gene transcription in zebrafish embryos.

    Science.gov (United States)

    Lyche, Jan L; Grześ, Irena M; Karlsson, Camilla; Nourizadeh-Lillabadi, Rasoul; Berg, Vidar; Kristoffersen, Anja B; Skåre, Janneche U; Alestrøm, Peter; Ropstad, Erik

    2013-01-15

    Determination of toxicity of complex mixtures has been proposed to be one of the most important challenges for modern toxicology. In this study we performed genome wide transcriptome profiling to assess potential toxicant induced changes in gene regulation in zebrafish embryos following parental exposure to two natural mixtures of persistent organic pollutants (POPs). The mixtures used were extracted from burbot (Lota lota) liver originating from two lakes (Lake Mjøsa and Lake Losna) belonging to the same freshwater system in Norway. The dominating groups of contaminants were polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane metabolites (DDTs). Because both mixtures used in the present study induced similar effects, it is likely that the same toxicants are involved. The Mjøsa mixture contains high levels of PBDEs while this group of pollutants is low in the Losna mixture. However, both mixtures contain substantial concentrations of PCB and DDT suggesting these contaminants as the predominant contributors to the toxicity observed. The observed effects included phenotypic traits, like embryo production and survival, and gene transcription changes corresponding with disease and biological functions such as cancer, reproductive system disease, cardiovascular disease, lipid and protein metabolism, small molecule biochemistry and cell cycle. The changes in gene transcription included genes regulated by HNF4A, insulin, LH, FSH and NF-κB which are known to be central regulators of endocrine signaling, metabolism, metabolic homeostasis, immune functions, cancer development and reproduction. The results suggest that relative low concentrations of the natural mixtures of POPs used in the present study might pose a threat to wild freshwater fish living in the lakes from which the POPs mixtures originated. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Chiral domain formation from the mixture of achiral rod-like liquid crystal and tri boomerang-shaped molecule

    Science.gov (United States)

    Lee, Ji-Hoon; Yoon, Tae-Hoon

    2013-08-01

    Spontaneous formation of chiral domains such as a helical filament and a bent-broom texture was observed from the mixture of a rod-like liquid crystal octylcyano-biphenyl (8CB) and a tri boomerang-shaped 2,4,6-triphenoxy-1,3,5-triazine (triphenoxy) molecule. Although the constituent molecules were achiral, their mixture showed the chiral domains with the equal fraction of the opposite handedness. No tilt of 8CB molecules in the smectic layer was observed, implying the chirality is not due to the polar packing and tilt of the molecules. In addition, the splay and bend elastic constant of 8CB was decreased after doping triphenoxy. A structural conformation of triphenoxy and an orientational coupling between 8CB and triphenoxy are considered to be related to the chiral domain formation.

  16. Natural convection in ternary mixtures

    International Nuclear Information System (INIS)

    Kremer, G.M.; Kai, L.

    1981-01-01

    The field equations for a mixture of a viscous fluid, a deformable solid and a non-viscous fluid are studied, based on a linearized theory proposed by Bowen. The fields of density of each constituent, temperature, velocity of each fluid and displacement of the solid are determined, for steady states flow of the mixture between two parallel planes and between two concentric cylinders which are maintained at diferent temperatures. (Author) [pt

  17. Centrifugal separation of mixture gases

    International Nuclear Information System (INIS)

    Zhou, M.S.; Chen, W.N.; Yin, Y.T.

    2008-01-01

    An attempt for single centrifugal separation of mixtures with different molecular formula was presented in this paper. The mixtures of SF 6 and CCl 3 F, and SF 6 and CCl 4 were chosen as the processing gases, which were prepared in three mass ratios, 0.5, 0.8 and 0.2, respectively. The separating characteristics such as the overall separation factors and the variation of cuts were studied. (author)

  18. Performance evaluation of Louisiana superpave mixtures.

    Science.gov (United States)

    2008-12-01

    This report documents the performance of Louisiana Superpave mixtures through laboratory mechanistic tests, mixture : volumetric properties, gradation analysis, and early field performance. Thirty Superpave mixtures were evaluated in this : study. Fo...

  19. Optimizing Polychlorinated Biphenyl Degradation by Flavonoid-Induced Cells of the Rhizobacterium Rhodococcus erythropolis U23A.

    Directory of Open Access Journals (Sweden)

    Thi Thanh My Pham

    Full Text Available There is evidence that many plant secondary metabolites may act as signal molecules to trigger the bacterial ability to metabolize polychlorinated biphenyls (PCBs during the rhizoremediation process. However, the bases for the PCB rhizoremediation process are still largely unknown. The rhizobacterium Rhodococcus erythropolis U23A is unable to use flavanone as a growth substrate. However, on the basis of an assay that monitors the amount of 4-chlorobenzoate produced from 4-chlorobiphenyl by cells grown co-metabolically on flavanone plus sodium acetate, this flavonoid was previously found to be a potential inducer of the U23A biphenyl catabolic pathway. In this work, and using the same assay, we identified ten other flavonoids that did not support growth, but that acted as inducers of the U23A biphenyl pathway, and we confirmed flavonoid induction of the biphenyl catabolic pathway using quantitative real-time polymerase chain reaction (RT-qPCR on the bphA gene. We also examined the effect of the growth co-substrate on flavonoid induction. Sodium acetate was replaced by glucose, mannose, sucrose, or mannitol, which are sugars found in plant root exudates. The data showed that the level of induction of strain U23A biphenyl-degrading enzymes was significantly influenced by the nature and concentration of the flavonoid in the growth medium, as well as by the substrate used for growth. Sucrose allowed for an optimal induction response for most flavonoids. Some flavonoids, such as flavone and isoflavone, were better inducers of the biphenyl catabolic enzymes than biphenyl itself. We also found that all flavonoids tested in this work were metabolized by strain U23A during co-metabolic growth, but that the metabolite profiles, as well as the level of efficiency of degradation, differed for each flavonoid. To obtain insight into how flavonoids interact with strain U23A to promote polychlorinated biphenyl (PCB degradation, we determined the concentration of

  20. Polychlorinated biphenyls (PCBs) in air and soil from a high-altitude pasture in the Italian Alps: evidence of CB-209 contamination.

    Science.gov (United States)

    Tremolada, Paolo; Guazzoni, Niccolò; Comolli, Roberto; Parolini, Marco; Lazzaro, Serena; Binelli, Andrea

    2015-12-01

    This study analyses the seasonal trend of polychlorinated biphenyls (PCB) concentrations in air and soil from a high-altitude mountain pasture in the Italian Alps. PCB concentrations in soil were generally comparable to background levels and were lower than those previously measured in the same area. Only CB-209 unexpectedly showed high concentrations with respect to the other congeners. GC-MS-MS identification was very clear, rising a new problem of increasing PCB contamination concerning only CB-209, which is not present in commercial mixtures used in the past in Italy and Europe. Considering all of the congeners, seasonal PCB trends were observed both in air and in soil that were related to the temperature and precipitation measured specifically in the study area. Highly significant relationships were found between the temperature-normalised concentrations in soil and the precipitation amounts. A north/south enrichment factor was present only in soil with rapid early summer re-volatilisation kinetics from soil to air and autumn re-deposition events from air to soil. Fugacity ratio calculations confirmed these trends. Surface soils respond rapidly to meteorological variables, while subsurface soils respond much more slowly. Seasonal trends were different for the northern and southern sides of the mountain. A detailed picture of the interactions among temperature, precipitation, mountain aspects and soil features was obtained.

  1. Determination of Chlorinated Pesticides and Polychlorinated Biphenyls in Edible Oils and Fats using MSPD Extraction and Freeze Lipids-Filtration Cleanup with GC-ECD Measurement

    International Nuclear Information System (INIS)

    Pla Jauregui, Daniela; Valcarcel Rojas, Lino; Estevez Alvarez, Juan

    2015-01-01

    Persistent organic pollutants (POPs) such as organo chlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) have numerous adverse effects on human health. Although their use have been banned or restricted, residues of these compounds can be found in foods, especially those with high fat content. The purpose of this study was to establish a rapid and simple analytical method for the determination of these compounds in edible oils and fats. Matrix solid-phase dispersion (MSPD) was used for the simultaneous extraction and purification of analytes from samples using an acetonitrile - acetone (19:1, v/v) mixture as eluting solvent. Lipids remaining in the extract were removed by freezing-lipid filtration, prior to analytes re-extraction with n-hexane. The measurement was performed using a gas chromatograph with electron capture detector (GC-ECD). Spiking experiments were carried out to determine the recovery, precision and limits of detection (LODs) of the method. Recoveries were higher than 70% and detection limits were in the range of 20 ng/g to 90 ng/g. These LOD values are lower than the maximum permissible limit which makes this method useful for the purpose intended. This method was successfully applied to the analysis of vegetable oils and butters sampled from the market. (Author)

  2. Nonparametric e-Mixture Estimation.

    Science.gov (United States)

    Takano, Ken; Hino, Hideitsu; Akaho, Shotaro; Murata, Noboru

    2016-12-01

    This study considers the common situation in data analysis when there are few observations of the distribution of interest or the target distribution, while abundant observations are available from auxiliary distributions. In this situation, it is natural to compensate for the lack of data from the target distribution by using data sets from these auxiliary distributions-in other words, approximating the target distribution in a subspace spanned by a set of auxiliary distributions. Mixture modeling is one of the simplest ways to integrate information from the target and auxiliary distributions in order to express the target distribution as accurately as possible. There are two typical mixtures in the context of information geometry: the [Formula: see text]- and [Formula: see text]-mixtures. The [Formula: see text]-mixture is applied in a variety of research fields because of the presence of the well-known expectation-maximazation algorithm for parameter estimation, whereas the [Formula: see text]-mixture is rarely used because of its difficulty of estimation, particularly for nonparametric models. The [Formula: see text]-mixture, however, is a well-tempered distribution that satisfies the principle of maximum entropy. To model a target distribution with scarce observations accurately, this letter proposes a novel framework for a nonparametric modeling of the [Formula: see text]-mixture and a geometrically inspired estimation algorithm. As numerical examples of the proposed framework, a transfer learning setup is considered. The experimental results show that this framework works well for three types of synthetic data sets, as well as an EEG real-world data set.

  3. Effects of defined mixtures of persistent organic pollutants (POPs) on multiple cellular responses in the human hepatocarcinoma cell line, HepG2, using high content analysis screening

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Jodie [Institute for Global Food Security, School of Biological Sciences, Queen' s University Belfast, Northern Ireland (United Kingdom); Berntsen, Hanne Friis; Zimmer, Karin Elisabeth [Norwegian University of Life Sciences, Oslo (Norway); Frizzell, Caroline [Institute for Global Food Security, School of Biological Sciences, Queen' s University Belfast, Northern Ireland (United Kingdom); Verhaegen, Steven; Ropstad, Erik [Norwegian University of Life Sciences, Oslo (Norway); Connolly, Lisa, E-mail: l.connolly@qub.ac.uk [Institute for Global Food Security, School of Biological Sciences, Queen' s University Belfast, Northern Ireland (United Kingdom)

    2016-03-01

    Persistent organic pollutants (POPs) are toxic substances, highly resistant to environmental degradation, which can bio-accumulate and have long-range atmospheric transport potential. Most studies focus on single compound effects, however as humans are exposed to several POPs simultaneously, investigating exposure effects of real life POP mixtures on human health is necessary. A defined mixture of POPs was used, where the compound concentration reflected its contribution to the levels seen in Scandinavian human serum (total mix). Several sub mixtures representing different classes of POPs were also constructed. The perfluorinated (PFC) mixture contained six perfluorinated compounds, brominated (Br) mixture contained seven brominated compounds, chlorinated (Cl) mixture contained polychlorinated biphenyls and also p,p’-dichlorodiphenyldichloroethylene, hexachlorobenzene, three chlordanes, three hexachlorocyclohexanes and dieldrin. Human hepatocarcinoma (HepG2) cells were used for 2 h and 48 h exposures to the seven mixtures and analysis on a CellInsight™ NXT High Content Screening platform. Multiple cytotoxic endpoints were investigated: cell number, nuclear intensity and area, mitochondrial mass and membrane potential (MMP) and reactive oxygen species (ROS). Both the Br and Cl mixtures induced ROS production but did not lead to apoptosis. The PFC mixture induced ROS production and likely induced cell apoptosis accompanied by the dissipation of MMP. Synergistic effects were evident for ROS induction when cells were exposed to the PFC + Br mixture in comparison to the effects of the individual mixtures. No significant effects were detected in the Br + Cl, PFC + Cl or total mixtures, which contain the same concentrations of chlorinated compounds as the Cl mixture plus additional compounds; highlighting the need for further exploration of POP mixtures in risk assessment. - Highlights: • High content analysis (HCA) is a novel approach for determining toxicity of

  4. Effects of defined mixtures of persistent organic pollutants (POPs) on multiple cellular responses in the human hepatocarcinoma cell line, HepG2, using high content analysis screening

    International Nuclear Information System (INIS)

    Wilson, Jodie; Berntsen, Hanne Friis; Zimmer, Karin Elisabeth; Frizzell, Caroline; Verhaegen, Steven; Ropstad, Erik; Connolly, Lisa

    2016-01-01

    Persistent organic pollutants (POPs) are toxic substances, highly resistant to environmental degradation, which can bio-accumulate and have long-range atmospheric transport potential. Most studies focus on single compound effects, however as humans are exposed to several POPs simultaneously, investigating exposure effects of real life POP mixtures on human health is necessary. A defined mixture of POPs was used, where the compound concentration reflected its contribution to the levels seen in Scandinavian human serum (total mix). Several sub mixtures representing different classes of POPs were also constructed. The perfluorinated (PFC) mixture contained six perfluorinated compounds, brominated (Br) mixture contained seven brominated compounds, chlorinated (Cl) mixture contained polychlorinated biphenyls and also p,p’-dichlorodiphenyldichloroethylene, hexachlorobenzene, three chlordanes, three hexachlorocyclohexanes and dieldrin. Human hepatocarcinoma (HepG2) cells were used for 2 h and 48 h exposures to the seven mixtures and analysis on a CellInsight™ NXT High Content Screening platform. Multiple cytotoxic endpoints were investigated: cell number, nuclear intensity and area, mitochondrial mass and membrane potential (MMP) and reactive oxygen species (ROS). Both the Br and Cl mixtures induced ROS production but did not lead to apoptosis. The PFC mixture induced ROS production and likely induced cell apoptosis accompanied by the dissipation of MMP. Synergistic effects were evident for ROS induction when cells were exposed to the PFC + Br mixture in comparison to the effects of the individual mixtures. No significant effects were detected in the Br + Cl, PFC + Cl or total mixtures, which contain the same concentrations of chlorinated compounds as the Cl mixture plus additional compounds; highlighting the need for further exploration of POP mixtures in risk assessment. - Highlights: • High content analysis (HCA) is a novel approach for determining toxicity of

  5. Mixture effects of 30 environmental contaminants on incident metabolic syndrome-A prospective study.

    Science.gov (United States)

    Lind, Lars; Salihovic, Samira; Lampa, Erik; Lind, P Monica

    2017-10-01

    Several cross-sectional studies have linked different environmental contaminants to the metabolic syndrome (MetS). However, mixture effects have not been investigated and no prospective studies exist regarding environmental contaminants and the MetS. To study mixture effects of contaminants on the risk of incident MetS in a prospective fashion. Our sample consisted of 452 subjects from the Prospective Study of the Vasculature in Uppsala Seniors (PIVUS) study (50% women, all aged 70years) free from the MetS at baseline, being followed for 10years. At baseline, 30 different environmental contaminants were measured; 6 polychlorinated biphenyls (PCBs), 3 organochlorine (OC) pesticides, one dioxin, one polybrominated diphenyl ether (all in plasma), 8 perfluoroalkyl substances (in plasma) and 11 metals (in whole blood). The MetS was defined by the ATPIII/NCEP criteria. Gradient boosted Classification and Regression Trees (CARTs) was used to evaluate potential synergistic and additive mixture effects on incident MetS. During 10-year follow-up, 92 incident cases of the MetS occurred. PCB126, PCB170, hexachlorobenzene (HCB) and PCB118 levels were all associated with incident MetS in an additive fashion (OR 1.73 for a change from 10th to 90th percentile (95%CI 1.24-3.04) for PCB126, OR 0.63 (0.42-0.78) for PCB170, OR 1.44 (1.09-2.20) for HCB and OR 1.46 (1.13-2.43) for PCB118). No synergistic effects were found. A mixture of environmental contaminants, with PCB126, PCB170, HCB and PCB118 being the most important, showed associations with future development of the MetS in an additive fashion in this prospective study. Thus, mixture effects of environmental contaminants could contribute to the development of cardio-metabolic derangements. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  6. Transient spectral hole burning observed on the single-molecule level in terrylene-doped biphenyl

    International Nuclear Information System (INIS)

    Pärs, M.; Palm, V.; Kikas, J.

    2014-01-01

    We use the method of fluorescence correlation spectroscopy to analyze the single-molecule (SM) spectroscopy data earlier recorded for a special type of terrylene SM impurity center (referred as “spectrally confined unstable molecule”, SCM) in an incommensurate single crystal of biphenyl. The SCM's SM line seems to be chaotically jumping around within a broad “spectral envelope” and was first considered being subject to a peculiar spectral diffusion behavior. However, our correlation analysis reveals that all the features observed for SCM at 1.8 K are consistent with an assumption that this SM center participates in a process of reversible (transient) spectral hole burning (THB) earlier observed for terrylene-doped polycrystalline biphenyl. No observations of THB processes on SM level have been so far reported for this impurity system, partially due to a low concentration of relevant impurity centers. Another reason making searching for such centers experimentally challenging is an unusual SM line behavior: the photoinduced transition to a metastable “dark state” leads to the SM line saturational broadening, which is much stronger than the triplet broadening. Hence required prolonged observation is often prevented by an SM act of persistent spectral hole burning. - Highlights: • SCM—special type of terrylene single-molecule center in incommensurate biphenyl. • An unusually stable SCM was investigated during several hours at T=1.8 K. • SCM undergoes photoinduced transitions to an unknown metastable “dark state” (DS). • The long DS lifetime causes strong saturational broadening of SCM spectral line. • SCM participates in an earlier observed process of transient hole burning

  7. Detection of Surface-Linked Polychlorinated Biphenyls using Surface-Enhanced Raman Scattering Spectroscopy

    DEFF Research Database (Denmark)

    Rindzevicius, Tomas; Barten, Jan; Vorobiev, Mikhail

    2017-01-01

    We present an improved procedure for analytical detection of toxic polychlorinated biphenyls (PCB) using surface-enhanced Raman scattering (SERS) spectroscopy. A gold-capped silicon nanopillar substrate was utilized to concentrate PCB molecules within an area of high electromagnetic fields through...... formation of microsized nanopillar clusters, and consequently, so-called “hot spots” can be formed. In order to improve PCB detection limit, 3,3',4,4'-tetrachlorobiphenyl (PCB77) compounds were chemically modified with a – SCH3 (PCB77-SCH3) group. Experimental and numerical analysis of vibrational modes...

  8. Secondary sex ratio in relation to exposures to polychlorinated biphenyls, dichlorodiphenyl dichloroethylene and methylmercury

    DEFF Research Database (Denmark)

    Timmermann, Clara Amalie Gade; Choi, Anna L; Petersen, Maria Skaalum

    2017-01-01

    This study was undertaken to assess the potential impact of maternal exposures to polychlorinated biphenyl (PCB), dichlorodiphenyl dichloroethylene (DDE) and methylmercury on the secondary sex ratios (the ratio of male to female live births) over a span of 23 years. The study includes prospective......% CI = 2-17%), respectively, of giving birth to a boy. In conclusion, maternal exposure to ΣPCB, DDE and methylmercury was associated with a slightly increased secondary sex ratio. The impact of paternal exposures could not be taken into account and deserves attention....

  9. Degradation of polychlorinated biphenyls in the rhizosphere of rape, Brassica napus L.

    Science.gov (United States)

    Javorská, Hana; Tlustos, Pavel; Kaliszová, Regina

    2009-06-01

    The objective of this study was to investigate the rhizosphere effect of rape plants on polychlorinated biphenyls (PCB) dissipation in soils spiked with seven indicator congeners. Depletion of PCB in the rhizosphere was significantly higher in the soil with lower organic matter content. While in the Chernozem soil, 87% of PCB related to bulk soil were found in the 1st mm from roots, only 62%-69% were found in the Fluvisol soil with no significant influence of increased initial PCB concentration. Further from the roots, the concentration of lower chlorinated congeners decreased, which indicates their greater biodegradation in comparison with more chlorinated ones.

  10. Polychlorinated biphenyls (PCBs) in the frame of the dismantling of nuclear facilities

    International Nuclear Information System (INIS)

    Hagenbart, Lars; Held, Christian; Reichert, Alexander

    2013-01-01

    During construction and maintenance of nuclear facilities PCB (polychlorinated biphenyls) containing paints were used in a large extent in the past. The WAK dismantling and disposal Company has dismantles such facilities and identified the PCB in the buildings. Besides the radionuclides the conventional hazardous material group of the PCBs has also to be disposed. The respective legal regulations have to be considered. In the frame of the contribution the radiological release of building structures with respect to re-use or demolition and residual PCB containing materials is discussed. The radiological disposal in final repositories and the conventional disposal regulations for releasable residual wastes are reported.

  11. Whole-Cell Fluorescent Biosensors for Bioavailability and Biodegradation of Polychlorinated Biphenyls

    Directory of Open Access Journals (Sweden)

    David Ryan

    2010-02-01

    Full Text Available Whole-cell microbial biosensors are one of the newest molecular tools used in environmental monitoring. Such biosensors are constructed through fusing a reporter gene such as lux, gfp or lacZ,to a responsive promoter. There have been many reports of the applications of biosensors, particularly their use in assaying pollutant toxicity and bioavailability. This paper reviews the basic concepts behind the construction of whole-cell microbial biosensors for pollutant monitoring, and describes the applications of two such biosensors for detecting the bioavailability and biodegradation of Polychlorinated Biphenyls (PCBs.

  12. Electrodialytic remediation of polychlorinated biphenyls contaminated soil with iron nanoparticles and two different surfactants

    DEFF Research Database (Denmark)

    Gomes, Helena I.; Dias-Ferreira, Celia; Ottosen, Lisbeth M.

    2014-01-01

    Polychlorinated biphenyls (PCB) are persistent organic pollutants (POP) that strongly adsorb in soils and sediments. There is a need to develop new and cost-effective solutions for the remediation of PCB contaminated soils. The suspended electrodialytic remediation combined with zero valent iron......ZVI showed encouraging tendencies and a base is thus formed for further optimization towards a new method for remediation of PCB polluted soils....... nanoparticles (nZVI) could be a competitive alternative to the commonly adapted solutions of incineration or landfilling. Surfactants can enhance the PCB desorption, dechlorination, and the contaminated soil cleanup. In this work, two different surfactants (saponin and Tween 80) were tested to enhance PCB...

  13. Mixtures of skewed Kalman filters

    KAUST Repository

    Kim, Hyoungmoon

    2014-01-01

    Normal state-space models are prevalent, but to increase the applicability of the Kalman filter, we propose mixtures of skewed, and extended skewed, Kalman filters. To do so, the closed skew-normal distribution is extended to a scale mixture class of closed skew-normal distributions. Some basic properties are derived and a class of closed skew. t distributions is obtained. Our suggested family of distributions is skewed and has heavy tails too, so it is appropriate for robust analysis. Our proposed special sequential Monte Carlo methods use a random mixture of the closed skew-normal distributions to approximate a target distribution. Hence it is possible to handle skewed and heavy tailed data simultaneously. These methods are illustrated with numerical experiments. © 2013 Elsevier Inc.

  14. Preparation of conducting solid mixtures

    International Nuclear Information System (INIS)

    Spokas, J.J.

    1978-01-01

    The application of conducting plastic mixtures to the fundamental problem of radiation dosimetry is briefly reviewed. A particular approach to achieving formulations with the necessary characteristics is described. A number of successful mixtures are defined for a number of different specific dosimetry situations. To obtain high quality stable materials requires intense blending and working of the materials at elevated temperatures. One machine that succeeds in this task is the Shonka plastics mixer-extruder. The Shonka mixer is described in complete detail. The procedures used in preparing representative formulations with this device are presented. A number of properties of successful conducting mixtures so prepared are summarized. The conditions required for molding such material are given. Several special welding methods for specific application with these formulations have been devised and are described

  15. Bayesian Kernel Mixtures for Counts.

    Science.gov (United States)

    Canale, Antonio; Dunson, David B

    2011-12-01

    Although Bayesian nonparametric mixture models for continuous data are well developed, there is a limited literature on related approaches for count data. A common strategy is to use a mixture of Poissons, which unfortunately is quite restrictive in not accounting for distributions having variance less than the mean. Other approaches include mixing multinomials, which requires finite support, and using a Dirichlet process prior with a Poisson base measure, which does not allow smooth deviations from the Poisson. As a broad class of alternative models, we propose to use nonparametric mixtures of rounded continuous kernels. An efficient Gibbs sampler is developed for posterior computation, and a simulation study is performed to assess performance. Focusing on the rounded Gaussian case, we generalize the modeling framework to account for multivariate count data, joint modeling with continuous and categorical variables, and other complications. The methods are illustrated through applications to a developmental toxicity study and marketing data. This article has supplementary material online.

  16. Toxicology of Chemical Mixtures: A Review of Mixtures Assessment

    National Research Council Canada - National Science Library

    Bjarnason, Stephen

    2004-01-01

    .... Recent advances in disciplines such as genomics, proteomics, metabonomics and physiologically-based pharmacokinetic modeling should assist in the hazard assessment of complex chemical mixtures. However, the process of regulatory assessment of these types of exposures will remain both complex and difficult.

  17. Carcinogenicity of individual and a mixture of dioxin-like compounds in female Harlan Sprague Dawley rats

    Energy Technology Data Exchange (ETDEWEB)

    Walker, N.; Nyska, A. [National Institute of Environmental Health Sciences, Research Triangle Park, NC (United States); Crockett, P. [Constella Group, Research Triangle Park, NC (US)] (and others)

    2004-09-15

    The human health risk posed by exposure to persistent organochlorine pollutants (POPs), including polychlorinated-dioxins (PCDDs), -furans (PCDFs) and - biphenyls (PCBs), present in the food and the environment is one of widespread concern throughout the industrialized world. The dioxin Toxic Equivalency Factor (TEF) approach is currently the most feasible interim approach for assessing and managing the risk posed by exposure to mixtures of these compounds and has been formally adopted by regulatory bodies in many countries, the International Programme on Chemical Safety and the World Health Organization. The TEF methodology is a relative potency scheme that estimates the total exposure and biological effects of a mixture of chemicals based on a common mechanism of action involving an initial binding of the compound to the Aryl hydrocarbon receptor (AhR). An implicit assumption of the TEF methodology is that the combined risk of effects of the different congeners is dose additive. Therefore, the total dioxin toxic equivalents (TEQs) of a mixture of PCDDs, PCDFs, and PCBs may be estimated by the summation of the mass of each compound in the mixture after adjustment for its potency relative to that of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). While dose additivity is supported for certain mixtures for some biological endpoints in some experimental models, this has never been evaluated for cancer risk. Here we present a summary of four chronic rodent bioassay conducted by the National Toxicology Program (US Department of Health and Human Services) that evaluated the carcinogenicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 3.3',4,4',5- pentachlorobiphenyl (PCB126) and 2,3,4,7,8 pentachlorodibenzofuran (PeCDF) and a mixture of these three dioxin-like compounds in female Harlan Sprague Dawley rats. Data from these studies will be used to test the hypothesis of dose-additivity of carcinogenicity by a defined mixture of dioxin-like compounds.

  18. Thermal mixtures in stochastic mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Guerra, F [Rome Univ. (Italy). Ist. di Matematica; Loffredo, M I [Salerno Univ. (Italy). Ist. di Fisica

    1981-01-17

    Stochastic mechanics is extended to systems in thermal equilibrium. The resulting stochastic processes are mixtures of Nelson processes. Their Markov property is investigated in some simple cases. It is found that in order to inforce Markov property the algebra of observable associated to the present must be suitably enlarged.

  19. Characterization of bioactive mixtures oligogalacturonidos

    International Nuclear Information System (INIS)

    Mederos Torres, Yuliem; Hormaza Montenegro, Josefa; Reynaldo Escobar, Ines; Montesino Sequi, Raquel

    2011-01-01

    Oligogalacturonides are pectic oligosaccharides composed of lineal chains of D-galacturonic acid, linked by α (1-4) glycosidic linkage. Oligogalacturonides' mixtures are obtained by enzymatic hydrolysis of pectins of diverse vegetal species. These oligosaccharides unchain a diverse biological activity in plants, which depends mainly on their polymerization degrees. The National Institute of Agricultural Science has a patent technology at national scale that lets to obtain a mixture of oligogalacturonides with different polymerization degree. In this work is presented the characterization of oligogalacturonides by spectrophotometric analysis attending to their uronic acids, reductor sugars, and neutral sugars content. Also the chromatographic profile of samples in study is obtained, using the derivatization with 2-aminobenzamide label and the separation by high pH anion exchange chromatography. It is achieved the separation of at least eight galacturonic acid oligomers with a variable degree of polymerization. On the other hand, the analysis by Fourier transform-infrared spectroscopy (FT-IR) showed that mixtures were composed by galacturonic acid salts. Results indicated that starting from two pectic acids with different characteristics, mixtures of oligogalacturonides of similar chemical composition could be obtained, but they differ in the proportion that they are presented

  20. Ecological Assembly of Chemical Mixtures

    Science.gov (United States)

    Human-environment interactions have a significant role in the formation of chemical mixtures in the environment and by extension in human tissues and fluids. These interactions, which include decisions to purchase and use products containing chemicals as well as behaviors and act...

  1. Transcriptional Response of Rhodococcus aetherivorans I24 to Polychlorinated Biphenyl-Contaminated Sediments

    KAUST Repository

    Puglisi, Edoardo

    2010-04-06

    We used a microarray targeting 3,524 genes to assess the transcriptional response of the actinomycete Rhodococcus aetherivorans I24 in minimal medium supplemented with various substrates (e. g., PCBs) and in both PCB-contaminated and non-contaminated sediment slurries. Relative to the reference condition (minimal medium supplemented with glucose), 408 genes were upregulated in the various treatments. In medium and in sediment, PCBs elicited the upregulation of a common set of 100 genes, including gene-encoding chaperones (groEL), a superoxide dismutase (sodA), alkyl hydroperoxide reductase protein C (ahpC), and a catalase/peroxidase (katG). Analysis of the R. aetherivorans I24 genome sequence identified orthologs of many of the genes in the canonical biphenyl pathway, but very few of these genes were upregulated in response to PCBs or biphenyl. This study is one of the first to use microarrays to assess the transcriptional response of a soil bacterium to a pollutant under conditions that more closely resemble the natural environment. Our results indicate that the transcriptional response of R. aetherivorans I24 to PCBs, in both medium and sediment, is primarily directed towards reducing oxidative stress, rather than catabolism. © 2010 Springer Science+Business Media, LLC.

  2. Atmospheric polychlorinated biphenyls in Indian cities: Levels, emission sources and toxicity equivalents

    International Nuclear Information System (INIS)

    Chakraborty, Paromita; Zhang, Gan; Eckhardt, Sabine; Li, Jun; Breivik, Knut; Lam, Paul K.S.; Tanabe, Shinsuke; Jones, Kevin C.

    2013-01-01

    Atmospheric concentration of Polychlorinated biphenyls (PCBs) were measured on diurnal basis by active air sampling during Dec 2006 to Feb 2007 in seven major cities from the northern (New Delhi and Agra), eastern (Kolkata), western (Mumbai and Goa) and southern (Chennai and Bangalore) parts of India. Average concentration of Σ 25 PCBs in the Indian atmosphere was 4460 (±2200) pg/m −3 with a dominance of congeners with 4–7 chlorine atoms. Model results (HYSPLIT, FLEXPART) indicate that the source areas are likely confined to local or regional proximity. Results from the FLEXPART model show that existing emission inventories cannot explain the high concentrations observed for PCB-28. Electronic waste, ship breaking activities and dumped solid waste are attributed as the possible sources of PCBs in India. Σ 25 PCB concentrations for each city showed significant linear correlation with Toxicity equivalence (TEQ) and Neurotoxic equivalence (NEQ) values. Highlights: •Unlike decreasing trend of PCBs in United States and European countries, high levels of PCBs remain in the Indian atmosphere. •Existing emission inventories cannot explain the high PCB concentrations in Indian atmosphere. •Electronic waste recycling, ship dismantling and open burning of municipal solid waste are implicated as potential sources. -- Measurement of atmospheric Polychlorinated biphenyls in seven major Indian cities

  3. Net trophic transfer efficiencies of polychlorinated biphenyl congeners to lake trout (Salvelinus namaycush) from its prey

    Science.gov (United States)

    Madenjian, Charles P.; David, Solomon R.; Rediske, Richard R.; O’Keefe, James P.

    2012-01-01

    Lake trout (Salvelinus namaycush) were fed bloater (Coregonus hoyi) in eight laboratory tanks over a 135-d experiment. At the start of the experiment, four to nine fish in each tank were sacrificed, and the concentrations of 75 polychlorinated biphenyl (PCB) congeners within these fish were determined. Polychlorinated biphenyl congener concentrations were also determined in the 10 lake trout remaining in each of the eight tanks at the end of the experiment as well as in the bloater fed to the lake trout. Each lake trout was weighed at the start and the end of the experiment, and the amount of food eaten by the lake trout was recorded. Using these measurements, net trophic transfer efficiency (γ) from the bloater to the lake trout in each of the eight tanks was calculated for each of the 75 congeners. Results showed that γ did not vary significantly with the degree of chlorination of the PCB congeners, and γ averaged 0.66 across all congeners. However,γ did show a slight, but significant, decrease as logKOW increased from 6.0 to 8.2. Activity level of the lake trout did not have a significant effect on γ.

  4. Polychlorinated biphenyls and reproductive hormones in female polar bears at Svalbard.

    Science.gov (United States)

    Haave, Marte; Ropstad, Erik; Derocher, Andrew E; Lie, Elisabeth; Dahl, Ellen; Wiig, Øystein; Skaare, Janneche U; Jenssen, Bjørn Munro

    2003-04-01

    High concentrations of polychlorinated biphenyls (PCBs) in polar bears from Svalbard have increased concern for that population's reproductive health. We examined whether there were associations between the plasma concentrations of PCBs and reproductive hormones [progesterone (P4)] and 17 beta-estradiol (E2)] in free-living female polar bears from Svalbard. Concentrations of P4 depended on reproductive status, and concentrations were lowest in females with offspring--females with cubs and females with yearlings. In these females, the P4 concentrations were positively correlated with plasma sigma PCBs (sum of all analyzed polychlorinated biphenyl congeners) concentrations. The sigma PCBs concentrations explained 27% of the variation in the P4 concentrations. There were no correlations between sigma PCBs and E2 and cortisol in any of the groups of polar bears, or between sigma PCBs and P4 in single polar bears. Although the sigma PCBs-P4 relationship in female polar bears with offspring is not evidence per se of a direct cause-effect association, the results indicate that PCBs may affect levels of P4 in polar bear females. There is a clear need to further assess the hormone balance and population health of polar bears at Svalbard.

  5. The associations between the environmental exposure to polychlorinated biphenyls (PCBs) and breast cancer risk and progression

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Polychlorinated biphenyls(PCBs) are chlorinated biphenyl compounds with wide applications in the industry.In spite of a ban on their production in the late 1970s,PCBs,as a group of POPs,are still persistent and widely spread in the environment,posing potential threats to human health.The role of PCBs as etiologic agents for breast cancer has been intensively explored in a variety of in vivo,animal and epidemiologic studies.Initial investigations indicated higher levels of PCBs in mammary tissues or sera corresponded to the occurrence of breast cancer,but later studies showed no positive association between PCB exposure and breast cancer development.More recent data suggested that the CYP1A1 m2 polymorphisms might add increased risk to the etiology of breast cancer in women with environmental exposure to PCBs.PCBs are implicated in advancing breast cancer progression,and our unpublished data reveals that PCBs activate the ROCK signaling to enhance breast cancer metastasis.Therefore,the correlation between PCB exposure and breast cancer risk warrants further careful investigations.

  6. Enhancing effect of spawning on elimination of a persistent polychlorinated biphenyl from female yellow perch

    International Nuclear Information System (INIS)

    Vodicnik, M.J.; Peterson, R.E.

    1985-01-01

    Distribution and elimination of 2,5,2',5'-tetrachloro[14C]biphenyl (4-CB) were studied for 6 months after exposing sexually mature female yellow perch to the compound in water and transferring them to flowing 4-CB-free water. Perch that were exposed in January spawned in May, and the study was terminated in June. During the first 41/2 months after exposure, the t1/2 for whole-body elimination was 22 weeks, primarily by elimination of 4-CB from the viscera and carcass. During spawning, enhanced elimination (t1/2 less than 0.7 weeks) was due to the voiding of eggs containing 4-CB. After spawning, whole-body elimination returned to a slower rate (t1/2 = 16.3 weeks). Prior to the enhancement in 4-CB elimination rate during spawning, there was a redistribution of 4-CB residues within the body of the perch which was characterized by a transfer of 4-CB residues from primarily the carcass and viscera to eggs. Two weeks after exposure, 30% of the initial 4-CB body burden was distributed to the eggs, whereas just prior to spawning, about 50% was present in this tissue. These findings demonstrate that egg maturation and spawning result in a significant reduction in the body burden of a persistent polychlorinated biphenyl in a lean-fish species

  7. Design, Synthesis, and Herbicidal Activity of Pyrimidine-Biphenyl Hybrids as Novel Acetohydroxyacid Synthase Inhibitors.

    Science.gov (United States)

    Li, Ke-Jian; Qu, Ren-Yu; Liu, Yu-Chao; Yang, Jing-Fang; Devendar, Ponnam; Chen, Qiong; Niu, Cong-Wei; Xi, Zhen; Yang, Guang-Fu

    2018-04-18

    The issue of weed resistance to acetohydroxyacid synthase (EC 2.2.1.6, AHAS) inhibitors has become one of the largest obstacles for the application of this class of herbicides. In a continuing effort to discover novel AHAS inhibitors to overcome weed resistance, a series of pyrimidine-biphenyl hybrids (4aa-bb and 5aa-ah) were designed and synthesized via a scaffold hopping strategy. Among these derivatives, compounds 4aa ( K i = 0.09 μM) and 4bb ( K i = 0.02 μM) displayed higher inhibitory activities against Arabidopsis thaliana AHAS than those of the controls bispyribac ( K i = 0.54 μM) and flumetsulam ( K i = 0.38 μM). Remarkably, compounds 4aa, 4bb, 5ah, and 5ag exhibited excellent postemergence herbicidal activity and a broad spectrum of weed control at application rates of 37.5-150 g of active ingredient (ai)/ha. Furthermore, 4aa and 4bb showed higher herbicidal activity against AHAS inhibitor-resistant Descurainia sophia, Ammannia arenaria, and the corresponding sensitive weeds than that of bispyribac at 0.94-0.235 g ai/ha. Therefore, the pyrimidine-biphenyl motif and lead compounds 4aa and 4bb have great potential for the discovery of novel AHAS inhibitors to combat AHAS-inhibiting herbicide-resistant weeds.

  8. Azo biphenyl polyurethane: Preparation, characterization and application for optical waveguide switch

    Science.gov (United States)

    Jiang, Yan; Da, Zulin; Qiu, Fengxian; Yang, Dongya; Guan, Yijun; Cao, Guorong

    2018-01-01

    Azo waveguide polymers are of particular interest in the design of materials for applications in optical switch. The aim of this contribution was the synthesis and thermo-optic waveguide switch properties of azo biphenyl polyurethanes. A series of monomers and azo biphenyl polyurethanes (Azo BPU1 and Azo BPU2) were synthesized and characterized by FT-IR, UV-Vis spectroscopy and 1H NMR. The physical and mechanical properties of thin polymer films were measured. The refractive index and thermo-optic coefficient (dn/dT) of polymer films were investigated for TE (transversal electric) polarizations by ATR technique. The transmission loss of film was measured using the Charge Coupled Device digital imaging devices. The results showed the Azo BPU2 containing chiral azobenzene chromophore had higher dn/dT and lower transmission loss. Subsequently, a 1 × 2 Y-branch and 2 × 2 Mach-Zehnder optical switches based on the prepared polymers were designed and simulated. The results showed that the power consumption of all switches was less than 1.0 mW. Compared with 1 × 2 Y-branch optical switch, the 2 × 2 Mach-Zehnder optical switches based on the same polymer have the faster response time, which were about only 1.2 and 2.0 ms, respectively.

  9. Hydroxy and methylsulfone metabolites of polychlorinated biphenyls in the human blood and tissues

    Energy Technology Data Exchange (ETDEWEB)

    Masuda, Yoshito; Haraguchi, Koichi [Daiichi College of Pharmaceutical Sciences, Fukuoka (Japan)

    2004-09-15

    Polychlorinated biphenyls (PCBs) are a group of chlorinated compounds which have polluted the global environment, persistently retained in wildlife and humans, and eventually affected the human health. PCBs are biotransformed to mainly hydroxy (HO-) and methylsulfone (MeSO{sub 2}-) metabolites in the animal and human tissues. About ten thousands of chemical and biological researches on PCBs, HOPCBs and MeSO{sub 2}-PCBs have been reported and reviewed so far. Letcher et al. cleverly reviewed the HO-PCBs and MeSO2-PCBs in 2000. We review the contamination of HO-PCBs and MeSO{sub 2}-PCBs in human tissues and their possible effects to human health. Different positional numberings of Cl-, HO- and MeSO{sub 2}- on biphenyl rings were used by different authors. Then, nomenclature of PCB metabolite was assessed by Maervoet et al. and they suggested to use the IUPAC chemical name and number of parent PCB congener with the subsequent assignment of the phenyl ring position number of the HO- or MeSO{sub 2}- substituent number afterward.

  10. Determination of levels of polychlorinated biphenyls (PCBs) present in caulk and window glazing material samples from older buildings

    Science.gov (United States)

    Levels of polychlorinated biphenyls (PCBs) in caulk and window glazing material samples from older buildings were determined, using a method developed for this purpose. This method was evaluated by analyzing a combination of 47 samples of caulk, glazing materials, including quali...

  11. Mixed function oxidase dependent biotransformation of polychlorinated biphenyls by different species of fish from the North Sea

    DEFF Research Database (Denmark)

    Mehrtens, G.; Laturnus, F.

    1999-01-01

    Mixed function oxidase (MFO) dependent biotransformation of polychlorinated biphenyls (PCBs) was measured in three different fish species from the North Sea. Liver microsomes of plaice (Pleuronectes platessa), dab (Limanda limanda) and cod (Gadus morhua) were isolated and incubated with different....... Biotransformations were also species dependent. The flatfish dab and plaice exhibited higher metabolic rates than cod (C) 1999 Elsevier Science Ltd. All rights reserved....

  12. Hydrogen–Hydrogen Bonding in Planar Biphenyl, Predicted by Atoms-In-Molecules Theory, Does Not Exist

    NARCIS (Netherlands)

    Poater, J; Sola, M.; Bickelhaupt, F.M.

    2006-01-01

    Based on an Atoms-in-Molecules (AIM) analysis, Matta et al. (Chem. Eur. J.2003, 9, 1940) recently claimed evidence for the existence of hydrogen–hydrogen bonding between ortho-hydrogen atoms, pointing towards each other from adjacent phenyl groups in planar biphenyl. This AIM result is opposed to

  13. Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and biphenyls (PCBs) in home-produced eggs

    NARCIS (Netherlands)

    Hoogenboom, L.A.P.; Dam, ten G.; Bruggen, van Mark; Jeurissen, Suzanne; Leeuwen, van S.P.J.; Theelen, R.M.C.; Zeilmaker, M.J.

    2016-01-01

    Home produced eggs from 62 addresses in the Netherlands were investigated for the levels of polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/Fs) and biphenyls (PCBs), both dioxin-like (dl) and non-dioxin-like (ndl). Compared to commercial eggs, levels were relatively high with a median of 4.6

  14. A SIMPLE AND FAST EXTRACTION METHOD FOR ORGANOCHLORINE PESTICIDES AND POLYCHLORINATED BIPHENYLS IN SMALL VOLUMES OF AVIAN SERUM

    Science.gov (United States)

    A solid-phase extraction (SPE) method was developed using 8 M urea to desorb and extract organochlorine pesticides (OCs) and polychlorinated biphenyls (PCBs) from avian serum for analysis by capillary gas chromatography with electron capture detection (GC-ECD). The analytes were ...

  15. Serum concentrations of polybrominated diphenyl ethers (PBDEs) and a polybrominated biphenyl (PBB) in men from Greenland, Poland and Ukraine

    DEFF Research Database (Denmark)

    Lenters, Virissa; Thomsen, Cathrine; Smit, Lidwien A M

    2013-01-01

    in Inuit men from across Greenland, and in men from Warsaw, Poland and Kharkiv, Ukraine. Serum was sampled between 2002 and 2004 from men 19 to 50years of age. 299 samples were analyzed for BDE-28, 47, 99, 100, 153, 154 and 183 and the brominated biphenyl BB-153 using gas chromatography-high resolution...

  16. 21 CFR 509.15 - Use of polychlorinated biphenyls (PCB's) in establishments manufacturing food-packaging materials.

    Science.gov (United States)

    2010-04-01

    ... establishments manufacturing food-packaging materials. 509.15 Section 509.15 Food and Drugs FOOD AND DRUG... polychlorinated biphenyls (PCB's) in establishments manufacturing food-packaging materials. (a) Polychlorinated...). These accidents in turn caused the contamination of food products intended for human consumption (meat...

  17. 21 CFR 109.15 - Use of polychlorinated biphenyls (PCB's) in establishments manufacturing food-packaging materials.

    Science.gov (United States)

    2010-04-01

    ... establishments manufacturing food-packaging materials. 109.15 Section 109.15 Food and Drugs FOOD AND DRUG... polychlorinated biphenyls (PCB's) in establishments manufacturing food-packaging materials. (a) Polychlorinated...). These accidents in turn caused the contamination of food products intended for human consumption (meat...

  18. Polychlorinated biphenyl rhizoremediation by Pseudomonas fluorescens F113 derivatives, using a Sinorhizobium meliloti nod system to drive bph gene expression

    Czech Academy of Sciences Publication Activity Database

    Villacieros, M.; Whelan, C.; Macková, Martina; Molgaard, J.; Sánchez-Contreras, M.; Lloret, J.; Cárcer de, D.; Oruezábal, R. I.; Bolanos, L.; Macek, Tomáš; Karlson, U.; Dowling, D. N.; Martín, M.; Rivilla, R.

    2005-01-01

    Roč. 71, č. 5 (2005), 2687-2694 ISSN 0099-2240 Grant - others:5thFW(XE) QLK3-CT-2001-00101; European Commission(XE) BIO4-CT97-2227 Institutional research plan: CEZ:AV0Z4055905 Keywords : polychlorinated biphenyls * rhizoremediation Subject RIV: CC - Organic Chemistry Impact factor: 3.818, year: 2005

  19. 77 FR 12836 - Draft Toxicological Review of Biphenyl: In Support of Summary Information on the Integrated Risk...

    Science.gov (United States)

    2012-03-02

    ... the draft human health assessment titled, ``Toxicological Review of Biphenyl: In Support of Summary... email: [email protected] . SUPPLEMENTARY INFORMATION: EPA's IRIS is a human health assessment... exposure to chemical substances found in the environment. Through the IRIS Program, EPA provides the...

  20. Proof of concept for the use of macroinvertebrates as indicators of polychlorinated biphenyls (PCB) contamination in Lake Hartwell

    Science.gov (United States)

    James M. Lazorchak; Michael B. Griffith; Marc Mills; Joseph Schubauer-Berigan; Frank McCormick; Richard Brenner; Craig Zeller

    2015-01-01

    The US Environmental Protection Agency (USEPA) develops methods and tools for evaluating risk management strategies for sediments contaminated with polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and other legacy pollutants. Monitored natural recovery is a risk management alternative that relies on existing physical, chemical, and biological...

  1. Environmental exposure to polychlorinated biphenyls (PCBs) and dioxins - Consequences for longterm neurological and cognitive development of the child. A Review

    NARCIS (Netherlands)

    Boersma, ER

    2001-01-01

    Polychlorinated biphenyl's (PCBs) and dioxins are environmental pollutants. Calculated on a body weight basis, prenatally as well as postnatally through breast-feeding, large amounts are transferred from mother to the child. Formula is free of these substances. Considering their potential

  2. Effects of environmental exposure to polychlorinated biphenyls and dioxins on cognitive abilities in Dutch children at 42 months of age

    NARCIS (Netherlands)

    Patandin, S; Lanting, Caren; Mulder, PGH; Boersma, ER; Sauer, PJJ; Weisglas-Kuperus, N

    Objective: To study possible adverse effects of environmental exposure to polychlorinated biphenyls (PCB) and dioxins on cognitive functioning in young children. Methods: In a follow-up of the Dutch PCB/Dioxin study, cognitive abilities were assessed with the Kaufman Assessment Battery for Children

  3. First worldwide UNEP interlaboratory study on persistent organic pollutants (POPs) with data on polychlorinated biphenyls and organochlorine pesticides

    NARCIS (Netherlands)

    Leeuwen, van S.P.J.; Bavel, van B.; Boer, de J.

    2013-01-01

    The first worldwide interlaboratory study on persistent organic pollutants (POPs) under the Stockholm Convention was organized, with a participation of 103 laboratories from Asia, Europe, the Americas, Africa and Australia, of which the majority submitted data on polychlorinated biphenyls (PCBs) and

  4. Mixtures in nonstable Levy processes

    International Nuclear Information System (INIS)

    Petroni, N Cufaro

    2007-01-01

    We analyse the Levy processes produced by means of two interconnected classes of nonstable, infinitely divisible distribution: the variance gamma and the Student laws. While the variance gamma family is closed under convolution, the Student one is not: this makes its time evolution more complicated. We prove that-at least for one particular type of Student processes suggested by recent empirical results, and for integral times-the distribution of the process is a mixture of other types of Student distributions, randomized by means of a new probability distribution. The mixture is such that along the time the asymptotic behaviour of the probability density functions always coincide with that of the generating Student law. We put forward the conjecture that this can be a general feature of the Student processes. We finally analyse the Ornstein-Uhlenbeck process driven by our Levy noises and show a few simulations of it

  5. Polychlorinated biphenyls, glycaemia and diabetes in a population living in a highly polychlorinated biphenyls-polluted area in northern Italy: a cross-sectional and cohort study

    Directory of Open Access Journals (Sweden)

    Claudia Zani

    2013-05-01

    Full Text Available Background. Polychlorinated biphenyls (PCBs have been found to be associated with diabetes in some, but not all, studies performed so far. The aim of this study was to assess the association between PCB serum levels and glycaemia and diabetes in people living in Brescia, a highly industrialised PCB-polluted town in Northern Italy. Design and Methods. 527 subjects were enrolled in a cross-sectional population-based study: they were interviewed face-to-face in 2003 and also provided a blood sample under fasting conditions. The concentration of 24 PCB congeners was determined using gas-chromatography (GC/MS. Subsequently, all subjects were included in a follow-up (cohort study. According to the Local Health Authority health-care database, subjects were considered to be diabetic if they had diabetes at interview time (prevalent cases or during a 7-year follow-up (incident cases. Results. A total of 53 subjects (10.0% were diabetics: 28 had dia- betes at enrolment and other 25 developed the disease subsequently. Diabetes frequency increased according to the serum concentrations of total PCBs and single PCB congeners, but no association was found when estimates were adjusted for education, body mass index, age and gender by logistic regression analysis. Accordingly, glycaemia increased with PCB serum levels, but no association was observed when multiple regression analysis, including confounding factors, was performed. Conclusions. This study does not support the hypothesis that PCB environmental exposure is strictly associated with diabetes or glycaemia.

  6. Accumulation of metabolites during bacterial degradation of PAH-mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Vila, J.; Lopez, Z.; Bauza, J.I. [Universitat de Barcelona (Spain). Department de Microbiologia; Minguillon, C. [Parc Cientific de Barcelona (ES). Institut de Recerca de Barcelona (IRB-PCB); Grifoll, M.

    2003-07-01

    In a previous work we identified a number of metabolites accumulated during growth in pyrene by Mycobacterium sp. AP1, and proposed a metabolic pathway for pyrene utilization. In order to confirm and complete this pathway we have isolated and identified the pyrene-degrading strains Mycobacterium sp. PGP2, CP1 and CP2. During growth on pyrene, strains AP1, PGP2, CP1 and CP2 accumulated 4,5-cis-pyrene-dihydrodiol, 4,5-phenanthrene dicarboxylic acid, 4-phenanthrene carboxylic acid, 3,4-dihydroxy-3-hydrophenanthrene-4-carboxylic acid, phthalic acid, and 6,6'-dihydroxy-2,2'-biphenyl dicarboxylic acid. Strains AP1, PGP2, CP1 and CP2 also grew on fluoranthene accumulating acenaphthenone, naphthalene-1,8-dicarboxylic acid, 9-fluorenone-1-carboxylic acid, Z-9-carboxymethylenefluorene-1-carboxylic acid and benzene-1,2,3-tricarboxylic acid. Similar metabolites were produced during growth onf fluoranthene by the Gram-positive strains CFt2 and CFt6, isolated by their capability of using this PAH as a sole source of carbon and energy. These fluoranthene-degrading strains also accumulated cis-1,9a-dihydroxy-1-hydrofluorene-9-one-8-carboxylic acid. In addition to pyrene and fluoranthene, all pyrene-degrading utilized phenanthrene as a sole source of carbon and energy, while the fluoranthene-degrading strains were unable to utilize pyrene or phenanthrene. Mycobacterium sp. AP1 acted on a wide range of PAHs, accumulating aromatic dicarboxylic acids, hydroxyacids, and ketones resulting from dioxygenation and ortho-cleavage, dioxygenation and meta-cleavage, and monooxygenation reactions. In cultures of strains AP1 and CP1 with a defined PAH-mixture only 20% removal of the parent compounds was observed. Analysis of acidic extracts showed the accumulation of the anticipated aromatic acids, suggesting that accumulation of acidic compounds could prevent further degradation of the mixture. Those results led us to isolation of strains DF11 and OH3, able to grow on the selected

  7. Consistency of the MLE under mixture models

    OpenAIRE

    Chen, Jiahua

    2016-01-01

    The large-sample properties of likelihood-based statistical inference under mixture models have received much attention from statisticians. Although the consistency of the nonparametric MLE is regarded as a standard conclusion, many researchers ignore the precise conditions required on the mixture model. An incorrect claim of consistency can lead to false conclusions even if the mixture model under investigation seems well behaved. Under a finite normal mixture model, for instance, the consis...

  8. Dirichlet Process Parsimonious Mixtures for clustering

    OpenAIRE

    Chamroukhi, Faicel; Bartcus, Marius; Glotin, Hervé

    2015-01-01

    The parsimonious Gaussian mixture models, which exploit an eigenvalue decomposition of the group covariance matrices of the Gaussian mixture, have shown their success in particular in cluster analysis. Their estimation is in general performed by maximum likelihood estimation and has also been considered from a parametric Bayesian prospective. We propose new Dirichlet Process Parsimonious mixtures (DPPM) which represent a Bayesian nonparametric formulation of these parsimonious Gaussian mixtur...

  9. Synthesis and characterization of tissue-retainable methylsulfonyl polychlorinated biphenyl isomers

    International Nuclear Information System (INIS)

    Haraguchi, K.; Kuroki, H.; Masuda, Y.

    1987-01-01

    Eighty-six positional isomers of methylsulfonyl polychlorinated biphenyls (MSF-PCBs) have been synthesized by three synthetic routes: (1) the diazo coupling reaction of 3-(methylsulfonyl)chloroaniline with chlorobenzene; (2) nucleophilic substitution of PCB with methanethiolate and successive oxidation of the corresponding methyl sulfide; (3) the diazo coupling reaction of chloroaniline with chlorothioanisole and successive oxidation of the methyl sulfide. Pure isomers were characterized by their proton magnetic resonance and mass spectra and used to unambiguously identify the MSF metabolites retained in human tissues by using high-resolution capillary gas chromatography (GC). The GC analysis showed that 40 MSF derivatives were positively identified in the tissue of a patient with Yusho on the basis of comparisons of their GC retention data with those of the standard compounds

  10. Distribution characteristics of polychlorinated biphenyls (PCBs) in coastal areas of Okinawa Island, Japan

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Surface sediment and seawater samples were collected from coastal areas around Okinawa Island from September 2001 to May 2002. The samples were analyzed for total polychlorinated biphenyl (PCB) levels and homolog composition. The results show that total PCB levels ranged from 0.32 to 128.7 ng/g (dry wt.) in sediment and 1.59 to 2.48 ng/L in seawater. The levels exceed the Environmental Quality Standard (EQS) for water pollution of Japan. The distribution of PCB homolog showed different patterns in the sediments and seawaters. Penta-chlorobiphenyls (CBs) comprised the main congener group in seawater, while hexa-CBs were more abundant homologs in the sediments. The heavily contaminated sites featured higher CBs, including penta-CBs, hexa-CBs, and hepta-CBs, than those in less contaminated sites where tri-CBs dominated. This study provides current distribution and geochemical behavior of PCBs in the coastal areas around Okinawa Island.

  11. Final report for Tank 100 Sump sludge (KON332) for polychlorinated biphenyl's (PCB)

    International Nuclear Information System (INIS)

    Fuller, R.K.

    1998-01-01

    Final Report for Tank 100 Sump Sludge (KON332) for Polychlorinated Biphenyl's (PCB) Sample Receipt Sample KON332 was received from Tank 100-Sump (WESF) on May 18, 1998. The laboratory number issued for this sample is S98BOO0207 as shown on the Request for Sample Analysis (RSA) form (Attachment 4). The sample breakdown diagram (Attachment 3) provides a cross-reference of customer sample identification to the laboratory identification number. Attachment 4 provides copies of the Request for Sample Analysis (RSA) and Chain of Custody (COC) forms. The sample was received in the laboratory in a 125-ml polybottle. Breakdown and subsampling was performed on June 6, 1998. PCB analysis was performed on the wet sludge. A discussion of the results is presented in Attachment 2. The 222-S extraction bench sheets are presented in Attachment 5. The PCB raw data are presented in Attachment 6

  12. Polychlorinated biphenyls (PCBs) in recreational marina sediments of San Diego Bay, southern California.

    Science.gov (United States)

    Neira, Carlos; Vales, Melissa; Mendoza, Guillermo; Hoh, Eunha; Levin, Lisa A

    2018-01-01

    Polychlorinated biphenyl (PCB) concentrations were determined in surface sediments from three recreational marinas in San Diego Bay, California. Total PCB concentrations ranged from 23 to 153, 31-294, and 151-1387ngg -1 for Shelter Island Yacht Basin (SIYB), Harbor Island West (HW) and Harbor Island East (HE), respectively. PCB concentrations were significantly higher in HE and PCB group composition differed relative to HW and SIYB, which were not significantly different from each other in concentration or group composition. In marina sediments there was a predominance (82-85%) of heavier molecular weight PCBs with homologous groups (6CL-7CL) comprising 59% of the total. In HE 75% of the sites exceeded the effect range median (ERM), and toxicity equivalence (TEQ dioxin-like PCBs) values were higher relative to those of HW and SIYB, suggesting a potential ecotoxicological risk. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. (Biphenyl-4-yl)methylammonium chlorides: potent anticonvulsants that modulate Na+ currents.

    Science.gov (United States)

    Lee, Hyosung; Park, Ki Duk; Yang, Xiao-Fang; Dustrude, Erik T; Wilson, Sarah M; Khanna, Rajesh; Kohn, Harold

    2013-07-25

    We have reported that compounds containing a biaryl linked unit (Ar-X-Ar') modulated Na(+) currents by promoting slow inactivation and fast inactivation processes and by inducing frequency (use)-dependent inhibition of Na(+) currents. These electrophysiological properties have been associated with the mode of action of several antiepileptic drugs. In this study, we demonstrate that the readily accessible (biphenyl-4-yl)methylammonium chlorides (compound class B) exhibited a broad range of anticonvulsant activities in animal models, and in the maximal electroshock seizure test the activity of (3'-trifluoromethoxybiphenyl-4-yl)methylammonium chloride (8) exceeded that of phenobarbital and phenytoin upon oral administration to rats. Electrophysiological studies of 8 using mouse catecholamine A-differentiated cells and rat embryonic cortical neurons confirmed that 8 promoted slow and fast inactivation in both cell types but did not affect the frequency (use)-dependent block of Na(+) currents.

  14. Problems with the polychlorinated biphenyls (PCB) in Mexico; Problematica de los bifenilos policlorados (BPC) en Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Valle, Esteban; Cruz, Maria Guadalupe [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1997-12-31

    A general overview is presented of the problems with the polychlorinated biphenyls (PCB) (askarels) in Mexico, which are mainly associated with the use of these substances in electric equipment; also, a profile of the causes why the PCBs have been classified as environmental toxic substances and a potential hazard for the health of human beings. [Espanol] Se presenta un panorama general de la problematica de bifenilos policlorados (BPC) (askareles) en Mexico, la cual esta asociada principalmente con el uso de estos compuestos en equipos electricos; asimismo, se describe una semblanza de las causas por las cuales se han catalogado a los BPC como sustancias toxicas ambientales y un peligro potencial para la salud de los seres humanos.

  15. Partitioning of naphthalene, methylnaphthalenes and biphenyl between wastewater treatment sludges and water

    International Nuclear Information System (INIS)

    Southworth, G.R.; Keller, J.L.

    1984-01-01

    Partition coefficients (K/sub p/) describing the partitioning of naphthalene, methylnaphthalenes and biphenyl between organic-rich wastes and water were determined using 14 C-tracer techniques as well as high performance liquid chromatographic analysis of the wastes and their aqueous extracts. Results of the two procedures were in good agreement. The concentrations of the specific organics in the wastes were not good predictors of concentrations in aqueous extracts, since K/sub p/ varied among the materials tested. Predictions of k/sub p/ based on organic carbon content of the sludges were well below observed values. Oil content of the wastes and oil-water partition coefficients appeared to be important factors in determining K/sub p/. 11 references, 5 tables

  16. Secondary sex ratio in relation to exposures to polychlorinated biphenyls, dichlorodiphenyl dichloroethylene and methylmercury

    DEFF Research Database (Denmark)

    Timmermann, Clara Amalie Gade; Choi, Anna L.; Petersen, Maria Skaalum

    2017-01-01

    This study was undertaken to assess the potential impact of maternal exposures to polychlorinated biphenyl (PCB), dichlorodiphenyl dichloroethylene (DDE) and methylmercury on the secondary sex ratios (the ratio of male to female live births) over a span of 23 years. The study includes prospective...... data from three Faroese birth cohorts, with a total of 2,152 healthy mother-child dyads recruited between 1986 and 2009. The Faroe Islands is a subarctic fishing community, where pilot whale meat and blubber are part of the traditional marine diet. Exposures were measured in maternal hair, serum...... or umbilical cord blood. Confounder adjusted logistic regression models were used to assess the associations between maternal exposures and the secondary sex ratio. A doubling in ΣPCB, p,p'-DDE and mercury concentrations were associated with increased odds by 8% (95% CI = 0-16%), 7% (95% CI = 0-14%) and 9% (95...

  17. Polychlorinated biphenyl concentrations in adipose tissue and abdominal obesity in the elderly

    DEFF Research Database (Denmark)

    Bräuner, Elvira; Raaschou-Nielsen, Ole; Andersen, Zorana

    2013-01-01

    Obesity prevalence has more than doubled globally within the last 30 years. Obesity affects quality of life as well as impacts the risks and prognosis for a number of serious diseases. Established causes include a high calorie diet combined with a sedentary lifestyle and possibly the widespread...... cessation of smoking, but these do not fully explain the epidemic. Polychlorinated biphenyl congeners (PCBs) are endocrine-disrupting chemicals and evidence from animal experiments suggests an association with obesity development. Our knowledge of the effects of these compounds on weight gain in humans...... is limited. Our objective was to investigate the association between exposure to PCBs experienced by a general Danish population and development of obesity. We randomly selected 204 persons (113 obese and 91 overweight), aged ≥ 50 years, from a prospective Danish cohort of 57,053 persons and examined ten...

  18. Solid phase extraction of polychlorinated biphenyls from water containing humic substances

    Energy Technology Data Exchange (ETDEWEB)

    Bonifazi, P.; Pierini, E.; Bruner, F. [Centro di Studio per la Chimica dell`Ambiente e le Tecnologie Strumentali Avanzate dell` Universita degli Studi di Urbino, Ist. di Scienze Chimiche (Italy)

    1997-06-01

    A study was carried out of the recovery by solid phase extraction of the eleven most toxic polychlorinated biphenyls from water containing humic acids. Experiments were performed using water polluted with a humic acid (sodium salt) concentration of 9-18 mg L{sup -1}. The effect of humic acids on the recoveries was noticeable, especially where the more chlorinated congeners were concerned. The effect was also evident with river water containing naturally dissolved humic acids. A method for destroying humic acids prior to extraction was applied. The recoveries after the destruction of humic acids were in the range of 90%, even in the case of river water, demonstrating the applicability of the method to real samples. (orig.)

  19. Problems with the polychlorinated biphenyls (PCB) in Mexico; Problematica de los bifenilos policlorados (BPC) en Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Valle, Esteban; Cruz, Maria Guadalupe [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1998-12-31

    A general overview is presented of the problems with the polychlorinated biphenyls (PCB) (askarels) in Mexico, which are mainly associated with the use of these substances in electric equipment; also, a profile of the causes why the PCBs have been classified as environmental toxic substances and a potential hazard for the health of human beings. [Espanol] Se presenta un panorama general de la problematica de bifenilos policlorados (BPC) (askareles) en Mexico, la cual esta asociada principalmente con el uso de estos compuestos en equipos electricos; asimismo, se describe una semblanza de las causas por las cuales se han catalogado a los BPC como sustancias toxicas ambientales y un peligro potencial para la salud de los seres humanos.

  20. Migration of CT triplet excitons in TCNB-biphenyl and TCNB-HMB crystals

    Science.gov (United States)

    Kozankiewicz, BolesAw

    1994-01-01

    Delayed fluorescence decay curves of charge transfer (CT) crystals of tetracyanobenzene with biphenyl (TCNB-B) and with hexamethylbenzene (TCNB-HMB) have been studied over a wide temperature range (5-200 K). The decay curves have been adequately described by decay expressions derived for different mechanisms of triplet-triplet annihilation. This analysis points to one-dimensional, thermally activated motion of CT triplet excitons. The estimated activation energies for the exciton hopping are 360±60 and 650±100 cm -1 (or 550±150 cm -1 depending on the applied model) for the TCNB-B and TCNB-HMB crystals, respectively. The results seem to confirm the self-trapping of triplet CT excitons.

  1. [Indoor air pollution by polychlorinated biphenyl compounds in permanently elastic sealants].

    Science.gov (United States)

    Burkhardt, U; Bork, M; Balfanz, E; Leidel, J

    1990-10-01

    A common cause for indoor pollution by polycholorinated biphenyls (PCB) are defective capacitors of luminous discharge lamps. This paper describes elastic sealing compounds as another source of PCB pollution in buildings. In several rooms of a large school building indoor concentrations of 1000 ng PCB/m3 and more were registered. The total PCB concentration in sealing compounds ranged between 124,000 and 327,000 ppm. Blood specimens drawn from the school's personnel did not show elevated PCB concentrations, but additional incorporation of PCB via the respiratory tract cannot be excluded. We do not presume that any impairment of the health has been caused by this pollutant, but we think that reduction of the PCB indoor concentrations would be advisable for prophylactic purposes. Attention should be given to so-called open PCB systems such as elastic sealing compounds. Although they have been prohibited 1978, there might be a widespread use in older buildings.

  2. Di-tert-butyl 2,2′-(biphenyl-2,2′-diyldioxydiacetate

    Directory of Open Access Journals (Sweden)

    Qamar Ali

    2008-08-01

    Full Text Available The title compound, C24H30O6, does not exhibit π–π interactions due to the steric effect of the bulky tert-butyl groups present in the molecule. The presence of these groups at the 2 and 2′ positions hinders the free motion of the benzene rings relative to each other, causing them to adopt an antiperiplanar arrangement. The benzene rings are twisted by just under 50.96 (17° with respect to each other. The carbonyl groups within the molecule are directed in different directions, one towards the biphenyl group and the other away from it. The molecules are linked together by C=O...H—C hydrogen bonds.

  3. Dioxins, furans, and polychlorinated biphenyls in hen eggs – a new source of hazard for consumers?

    Directory of Open Access Journals (Sweden)

    Piskorska-Pliszczyńska Jadwiga

    2015-12-01

    Full Text Available The paper presents the results of testing eggs for the content of dioxins and polychlorinated biphenyls (PCBs, determination of the sources that caused the presence of high concentrations of these compounds which exceeded the acceptable contamination levels, and assessment of consumer health risk caused by the consumption of eggs with excessive contents of investigated compounds. In about 9% of free range eggs and 17% of organic eggs, the content of PCDD/Fs was two- or threefold higher than the acceptable limits, and in some samples the concentration of investigated compounds exceeded the maximum concentration levels. Based on the profile of the compounds, it was confirmed in several cases that their main source was the soil or unsecured refuse. The consumers of eggs and meat produced under these conditions constitute the risk groups, and their dioxin and PCB intake may exceed toxicological reference values.

  4. Intergenerational effects of endocrine-disrupting compounds: a review of the Michigan polybrominated biphenyl registry.

    Science.gov (United States)

    Curtis, Sarah W; Conneely, Karen N; Marder, Mary E; Terrell, Metrecia L; Marcus, Michele; Smith, Alicia K

    2018-06-11

    Endocrine-disrupting compounds (EDCs) are a broad class of chemicals present in many residential products that can disrupt hormone signaling and cause health problems in humans. Multigenerational cohorts, like the Michigan polybrominated biphenyl registry, are ideal for studying the effects of intergenerational exposure. Registry participants report hormone-related health problems, particularly in those exposed before puberty or those in the second generation exposed through placental transfer or breastfeeding. However, more research is needed to determine how EDCs cause health problems and the mechanisms underlying intergenerational exposure. Utilizing existing data in this registry, along with genetic and epigenetic approaches, could provide insight to how EDCs cause human disease and help to determine the risk to exposed populations and future generations.

  5. Organochlorine Pesticides (OCs) and Polychlorinated Biphenyls (PCBs) in Tilapia zillii from Lake El-Manzala, Egypt

    International Nuclear Information System (INIS)

    El-Greisy, Zeinab Abdalbagi; Abdallah, A. Mohamed Ali

    2005-01-01

    A fresh water fish species, (Tilapia zillii) from Lake El-Manzala was analyzed for concentrations of several Organochlorine pesticides (OCs) and Polychlorine piphenyl's (PCBs) in liver, gonads, mesenteric fat, flesh and the digestive tract in mature fish during the breeding season. Polychlorinated piphenyls (PCBs) and Organochloripe pesticides (OCs) were calculated in (ng/g) dry weight (dw) in homogenized samples. The obtained results revealed differences in lipid content between these different organs. The females showed higher lipid content than males. There was significant positive correlation the lipid content and organochlorines and polychlorinated biphenyls (PCBs). The results come concomitant with the lipophilicity of studied compounds. However, the recoded concentration of these studied pollutants still does not exceed international hazardous levels. (author)

  6. Persistent organochlorine residues and toxic evaluation of polychlorinated biphenyls in sharks from the Mediterranean Sea (Italy)

    Energy Technology Data Exchange (ETDEWEB)

    Storelli, M.M.; Marcotrigiano, G.O. [Bari Univ., Dip. Farmaco-Biologico, Bari (Italy)

    2001-07-01

    Persistent organochlorines such as polychlorinated biphenyls including coplanar congeners, DDT compounds and HCB were measured in different tissues (muscle, liver and eggs) of two Mediterranean shark species: namely Centrophorus granulosus and Squalus blainvillei. The concentrations of organochlorines in the tissues and organs of both species were in the order DDTs>PCBs>HCB. The highest values of DDTs, PCBs and HCB were found in liver followed by eggs and muscle. Among DDTs the compound found in greatest concentration was p,p -DDE. The PCB profiles were dominated by congeners 138, 153, and 180. The isomers with higher TEQs values were non- and mono-ortho congeners than di-ortho ones in muscle, liver and eggs of both species. Among the non-ortho, PCB 126 was the major contributing individual to the total TEQs in both species. (Author)

  7. Temporal Trends of Hexabromocyclododecane, Polybrominated Diphenyl Ethers and Polychlorinated Biphenyls in Ringed Seals from East Greenland

    DEFF Research Database (Denmark)

    Vorkamp, Katrin; Riget, Frank Farsø; Bossi, Rossana

    2011-01-01

    also was found for adult seals with a time trend starting in 1994. ΣPCB decreased significantly in juvenile seals, again due to the 1986 value, while no trend was found for the adult animals. This indicates stagnating PCB concentrations at a relatively high level, in some cases possibly exceeding......Concentrations of hexabromocyclododecane (HBCD) were determined in a combination of archived and fresh blubber samples of juvenile ringed seals from East Greenland collected between 1986 and 2008. R-HBCD was the only diastereoisomer consistently above levels of quantification and showed...... on polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) have been extended with new data for 2006 and 2008. ΣPBDE in juvenile seals was the only parameter with a slight upward trend, however, dependent on the low 1986 concentration. Removing this data point resulted in a downward trend, which...

  8. Tissue deposition of polychlorinated biphenyls in cats fed Atlantic Ocean bluefish.

    Science.gov (United States)

    Carbone, L G; Alo, D K; Scarlett, J M; Gutenmann, W H; Lisk, D J

    1991-07-01

    Bluefish (Pomatomus saltatrix), a very popular marine sport fish caught in Atlantic coastal waters, contain significant levels of polychlorinated biphenyls (PCBs). Since fish can be an appreciable portion of human and feline diets, a feeding study was conducted with cats fed exclusively bluefish for 86 days with determination of tissue concentrations of PCBs. The concentrations of PCBs in brain, liver, and fat were significantly higher (p = 0.01) in the fish-fed cats than in the control group using the Wilcoxon rank sum test. The highest PCB levels were in fat, the median concentrations being 48 and 0.61 ppm (dry weight) in the fish-fed and control cats, respectively. The significance of the results is discussed.

  9. Some properties of explosive mixtures containing peroxides

    International Nuclear Information System (INIS)

    Zeman, Svatopluk; Trzcinski, Waldemar A.; Matyas, Robert

    2008-01-01

    This study concerns mixtures of triacetone triperoxide (3,3,6,6,9,9-hexamethyl-1,2,4,5,7,8-hexoxonane, TATP) and ammonium nitrate (AN) with added water (W), as the case may be, and dry mixtures of TATP with urea nitrate (UN). Relative performances (RP) of the mixtures and their individual components, relative to TNT, were determined by means of ballistic mortar. The detonation energies, E 0 , and detonation velocities, D, were calculated for the mixtures studied by means of the thermodynamic code CHEETAH. Relationships have been found and are discussed between the RP and the E 0 values related to unit volume of gaseous products of detonation of these mixtures. These relationships together with those between RP and oxygen balance values of the mixtures studied indicate different types of participation of AN and UN in the explosive decomposition of the respective mixtures. Dry TATP/UN mixtures exhibit lower RP than analogous mixtures TATP/AN containing up to 25% of water. Depending on the water content, the TATP/AN mixtures possess higher detonability values than the ANFO explosives. A semi-logarithmic relationship between the D values and oxygen coefficients has been derived for all the mixtures studied at the charge density of 1000 kg m -3 . Among the mixtures studied, this relationship distinguishes several samples of the type of 'tertiary explosives' as well as samples that approach 'high explosives' in their performances and detonation velocities

  10. Sex dependence of the components and structure of urinary calculi induced by biphenyl administration in rats.

    Science.gov (United States)

    Ohnishi, M; Yajima, H; Yamamoto, S; Matsushima, T; Ishii, T

    2000-08-01

    To obtain definitive information about the mechanisms of urinary calculus formation and the structural characteristics of the calculi induced by biphenyl administration in rats, with a focus on the sex dependency, the constituents of the urinary calculi were analyzed by HPLC, inductively coupled plasma spectroscopy (ICP), micro Fourier transform infrared spectroscopy (mFT-IR), and ion chromatography (IC), and structural analyses were carried out by microscopy, mFT-IR, and the electron probe microanalyzer (EPMA) method. We attempted to account for the appreciably higher incidence of calculi in males than in females. mFT-IR analysis revealed that the biphenyl-induced urinary calculi in male rats are composed mainly of potassium 4-hydroxybiphenyl-o-sulfate (4-HBPOSK), whereas the calculi in female rats are composed mainly of 4-hydroxybiphenyl (4-HBP) and KHSO(4) produced by the hydrolysis of 4-HBPOSK. Observations of photomicrographs and the results of mFT-IR analysis indicated that the calculi in males have a multilayer structure consisting of alternating layers of 4-HBPOSK and calcium phosphate, whereas the calculi in females have no multilayer structure, but open holes in which needle-shaped crystals are present in some places. In view of the results of these analyses, including the EPMA analysis, it appears that calculus formation in males may involve a series of successive and irreversible reactions, whereas calculus formation in females may result from a series of reversible reactions, including the hydrolysis of 4-HBPOSK. It was inferred that the series of irreversible reactions involved in calculus formation in males is relatively more stable than that in the case of females, and thus, a sex difference in the reaction features may be responsible for the observed difference in the incidence of calculus formation.

  11. Assessment of polychlorinated biphenyls and organochlorine pesticides in water samples from the Yamuna River

    Directory of Open Access Journals (Sweden)

    Bhupander Kumar

    2012-07-01

    Full Text Available Polychlorinated biphenyls (PCBs, hexachlorocyclohexane (HCH and dichlorodiphenyltrichloroethane (DDT are toxic, persistent and bioaccumulative long-range atmospheric transport pollutants. These are transported worldwide affecting remote regions far from their original sources, and can transfer into food webs with a wide range of acute and chronic health effects. India ratified the Stockholm Convention with the intention of reducing and eliminating persistent organic pollutants (POPs, and encouraged the support of research on POPs. Despite the ban and restriction on the use of these chemicals in India, their contamination of air, water, sediment, biota and humans has been reported. In this study, surface water samples were collected during January 2012 from the Yamuna River in Delhi, India, and analyzed for PCBs and organochlorine pesticides (OCPs. The concentrations of ΣPCBs and ΣOCPs ranged between 2-779 ng L–1 and from less than 0.1 to 618 ng L–1 (mean 99±38 ng L–1 and 221±50 ng L–1, respectively. The PCB homolog was dominated by 3-4 chlorinated biphenyls. In calculating the toxicity equivalent of dioxin-like PCBs (dl-PCBsusing World Health Organization toxic equivalency factors, dl-PCBs accounted for 10% of a total of 27 PCBs. The concentration of ΣHCH ranged between less than 0.1 and 285 ng L–1 (mean 151±32 ng L–1. However, ΣDDTs concentrations varied between less than 0.1 and 354 ng L–1 (mean 83±26 ng L–1. The concentrations were lower than the US guideline values; however, levels of lindane exceeded those recommended in guidelines. Further in-depth study is proposed to determine the bioaccumulation of these pollutants through aquatic biota to assess the risk of contaminants to human health.

  12. Chlorinated hydrocarbon pesticides and polychlorinated biphenyls in sediment cores from San Francisco Bay

    Science.gov (United States)

    Venkatesan, M.I.; De Leon, R. P.; VanGeen, A.; Luoma, S.N.

    1999-01-01

    Sediment cores of known chronology from Richardson and San Pablo Bays in San Francisco Bay, CA, were analyzed for a suite of chlorinated hydrocarbon pesticides and polychlorinated biphenyls to reconstruct a historic record of inputs. Total DDTs (DDT = 2,4'- and 4,4'-dichlorodiphenyltrichloroethane and the metabolites, 2,4'- and 4,4'-DDE, -DDD) range in concentration from 4-21 ng/g and constitute a major fraction (> 84%) of the total pesticides in the top 70 cm of Richardson Bay sediment. A subsurface maximum corresponds to a peak deposition date of 1969-1974. The first measurable DDT levels are found in sediment deposited in the late 1930's. The higher DDT inventory in the San Pablo relative to the Richardson Bay core probably reflects the greater proximity of San Pablo Bay to agricultural activities in the watershed of the Sacramento and San Joaquin rivers. Total polychlorinated biphenyls (PCBs) occur at comparable levels in the two Bays (inventories in San Pablo Bay are about a factor of four higher in the last four decades than in Richardson Bay, suggesting a distribution of inputs not as strongly weighed towards the upper reaches of the estuary as DDTs. The shallower subsurface maximum in PCBs compared to DDT in the San Pablo Bay core is consistent with the imposition of drastic source control measures four these constituents in 1970 and 1977 respectively. The observed decline in DDT and PCB levels towards the surface of both cores is consistent with a dramatic drop in the input of these pollutants once the effect of sediment resuspension and mixing is taken into account.

  13. Atropisomerism in a new type biphenyl and o-terphenyl condensed tannins. Atropisomerie in nuwe tipe bifeniel en o-terfeniel gekondenseerde tanniene

    Energy Technology Data Exchange (ETDEWEB)

    Young, E

    1984-03-01

    Chemical investigation of the core wood Prosopis glandulosa has revealed that it has a complex flavenoid content. The predominant phenolic component of the core wood is flavan-3-ol with a 3/sup ,/,4/sup ,/,7,8-tetrahydroxy phenolic substitute pattern. Apart from the isolation of 'conventionally' coupled biflavenoids based on electrophilic attack at the C/sub 4/-carbeniumion from flavan-3,4-diol on the nucleophilic positions of flavan-3-ols, a new 1-flavenyl-1,3-diarylpropan-2-ol as wel as a B-ring coupled flavenyl-2-benzoylbenzofuran was isolated. The uniqueness of this study lies in the identification of (5,6)-coupled and atropisomeric (5,5)-biflavenoids based on a biphenyl bond which was extended to the triflavenoid level with the identification of four (5,5:5,6)-0-terphenyl triflavenoidatropisomers. The /sup 1/H nmr spectra of the 5,5-dimers and (5,5:5,6)-trimers exhibit sharply defined spectra at room temperatures which suggests rigidity of structure at these temperatures. Further proof of atropisomerism at the (5,5)-coupled dimers was obtained by means of an isomerization experiment. At the (5,6)-coupled isomers, a dynamic equilibrium at the /sup 1/H nmr-spectra of the methyl etheracetate derivatives was observed. Synthesis of the optically pure (4,6)-biflavenoid with 3/sup ,/,4/sup ,/,7,8-tetrahydroxylation pattern was, conducted through reduction of (+-)-3/sup ,/,4,7,8-tetramethoxydihydroflavonol, condensation of it to the monomeric (+)-3/sup ,/,4/sup ,/,7,8-tetrahydroxyflavan-3-ol and subsequent separation of the diastereo-isomeric mixture.

  14. Multi-contamination (heavy metals, polychlorinated biphenyls and polycyclic aromatic hydrocarbons) of littoral sediments and the associated ecological risk assessment in a large lake in France (Lake Bourget).

    Science.gov (United States)

    Lécrivain, Nathalie; Aurenche, Vincent; Cottin, Nathalie; Frossard, Victor; Clément, Bernard

    2018-04-01

    The lake littoral sediment is exposed to a large array of contaminants that can exhibit significant spatial variability and challenge our ability to assess contamination at lake scale. In this study, littoral sediment contamination was characterized among ten different sites in a large peri-alpine lake (Lake Bourget) regarding three groups of contaminants: 6 heavy metals, 15 polycyclic aromatic hydrocarbons and 7 polychlorinated biphenyls. The contamination profiles significantly varied among sites and differed from those previously reported for the deepest zone of the lake. An integrative approach including chemical and biological analyses was conducted to relate site contamination to ecological risk. The chemical approach consisted in mean PEC quotient calculation (average of the ratios of the contaminants concentration to their corresponding Probable Effect Concentration values) and revealed a low and heterogeneous toxicity of the contaminant mixture along the littoral. Biological analysis including both laboratory (microcosm assays) and in situ (Acetylcholine Esterase (AChE) and Glutathione S-Transferase (GST) activity measurements) experiments highlighted significant differences among sites both in the field and in laboratory assays suggesting a spatial variation of the biota response to contamination. Linear regressions were performed between mean PEC quotients and biological results to assess whether littoral ecological risk was explained by the contamination profiles. The results highly depended on the study benthic or pelagic compartment. Regarding autochthonous Corbicula fluminea, no significant relationship between mean PEC quotients and biomarker activity was found while a significant increase in AChE was observed on autochthonous chironomids, suggesting different stress among benthic organisms. Both AChE and GST in caged pelagic Daphnia magna showed a significant positive relationship with mean PEC quotients. This study underlines the importance of

  15. Contamination of indoor dust and air by polychlorinated biphenyls and brominated flame retardants and relevance of non-dietary exposure in Vietnamese informal e-waste recycling sites.

    Science.gov (United States)

    Tue, Nguyen Minh; Takahashi, Shin; Suzuki, Go; Isobe, Tomohiko; Viet, Pham Hung; Kobara, Yuso; Seike, Nobuyasu; Zhang, Gan; Sudaryanto, Agus; Tanabe, Shinsuke

    2013-01-01

    This study investigated the occurrence of polychlorinated biphenyls (PCBs), and several additive brominated flame retardants (BFRs) in indoor dust and air from two Vietnamese informal e-waste recycling sites (EWRSs) and an urban site in order to assess the relevance of these media for human exposure. The levels of polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), 1,2-bis-(2,4,6-tribromophenoxy)ethane (BTBPE) and decabromodiphenyl ethane (DBDPE) in settled house dust from the EWRSs (130-12,000, 5.4-400, 5.2-620 and 31-1400 ng g(-1), respectively) were significantly higher than in urban house dust but the levels of PCBs (4.8-320 ng g(-1)) were not higher. The levels of PCBs and PBDEs in air at e-waste recycling houses (1000-1800 and 620-720 pg m(-3), respectively), determined using passive sampling, were also higher compared with non-e-waste houses. The composition of BFRs in EWRS samples suggests the influence from high-temperature processes and occurrence of waste materials containing older BFR formulations. Results of daily intake estimation for e-waste recycling workers are in good agreement with the accumulation patterns previously observed in human milk and indicate that dust ingestion contributes a large portion of the PBDE intake (60%-88%), and air inhalation to the low-chlorinated PCB intake (>80% for triCBs) due to their high levels in dust and air, respectively. Further investigation of both indoor dust and air as the exposure media for other e-waste recycling-related contaminants and assessment of health risk associated with exposure to these contaminant mixtures is necessary. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Simultaneous analysis of organochlorinated pesticides (OCPs) and polychlorinated biphenyls (PCBs) from marine samples using automated pressurized liquid extraction (PLE) and Power Prep™ clean-up.

    Science.gov (United States)

    Helaleh, Murad I H; Al-Rashdan, Amal; Ibtisam, A

    2012-05-30

    An automated pressurized liquid extraction (PLE) method followed by Power Prep™ clean-up was developed for organochlorinated pesticide (OCP) and polychlorinated biphenyl (PCB) analysis in environmental marine samples of fish, squid, bivalves, shells, octopus and shrimp. OCPs and PCBs were simultaneously determined in a single chromatographic run using gas chromatography-mass spectrometry-negative chemical ionization (GC-MS-NCI). About 5 g of each biological marine sample was mixed with anhydrous sodium sulphate and placed in the extraction cell of the PLE system. PLE is controlled by means of a PC using DMS 6000 software. Purification of the extract was accomplished using automated Power Prep™ clean-up with a pre-packed disposable silica column (6 g) supplied by Fluid Management Systems (FMS). All OCPs and PCBs were eluted from the silica column using two types of solvent: 80 mL of hexane and a 50 mL mixture of hexane and dichloromethane (1:1). A wide variety of fish and shellfish were collected from the fish market and analyzed using this method. The total PCB concentrations were 2.53, 0.25, 0.24, 0.24, 0.17 and 1.38 ng g(-1) (w/w) for fish, squid, bivalves, shells, octopus and shrimp, respectively, and the corresponding total OCP concentrations were 30.47, 2.86, 0.92, 10.72, 5.13 and 18.39 ng g(-1) (w/w). Lipids were removed using an SX-3 Bio-Beads gel permeation chromatography (GPC) column. Analytical criteria such as recovery, reproducibility and repeatability were evaluated through a range of biological matrices. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. TRANSPORT PROPERTIES FOR REFRIGERANT MIXTURES

    Directory of Open Access Journals (Sweden)

    V. Geller

    2014-06-01

    Full Text Available A set of models to predict viscosity and thermal conductivity of refrigerant mixtures is developed. A general model for viscosity and thermal conductivity use the three contributions sum form (the dilute-gas terms, the residual terms, and the liquid terms. The corresponding states model is recommended to predict the dense gas transport properties over a range of reduced density from 0 to 2. It is shown that the RHS model provides the most reliable results for the saturated-liquid and the compressed-liquid transport properties over a range of given temperatures from 0,5 to 0,95.

  18. Nonparametric Mixture of Regression Models.

    Science.gov (United States)

    Huang, Mian; Li, Runze; Wang, Shaoli

    2013-07-01

    Motivated by an analysis of US house price index data, we propose nonparametric finite mixture of regression models. We study the identifiability issue of the proposed models, and develop an estimation procedure by employing kernel regression. We further systematically study the sampling properties of the proposed estimators, and establish their asymptotic normality. A modified EM algorithm is proposed to carry out the estimation procedure. We show that our algorithm preserves the ascent property of the EM algorithm in an asymptotic sense. Monte Carlo simulations are conducted to examine the finite sample performance of the proposed estimation procedure. An empirical analysis of the US house price index data is illustrated for the proposed methodology.

  19. A cohort study of the association between secondary sex ratio and parental exposure to polybrominated biphenyl (PBB and polychlorinated biphenyl (PCB

    Directory of Open Access Journals (Sweden)

    Terrell Metrecia L

    2009-08-01

    Full Text Available Abstract Background Polybrominated biphenyl (PBB, a brominated flame retardant, was accidently mixed into animal feed in Michigan (1973–1974 resulting in human exposure through consumption of contaminated meat, milk and eggs. Beginning in 1976 individuals who consumed contaminated products were enrolled in the Michigan Long-Term PBB Study. This cohort presents a unique opportunity to study the association between parental exposures to PBB and offspring sex ratio. Methods We identified offspring of female PBB cohort participants (born 1975–1988 and obtained electronic birth records for those born in the state of Michigan. We linked this information to parental serum PBB and PCB concentrations collected at enrollment into the cohort. We modeled the odds of a male birth with generalized estimating equations accounting for the non-independence of siblings born to the same parents. We explored potential confounders: parental age and education at offspring's birth, parental body mass index at cohort enrollment, birth order, gestational age and year of offspring's birth. Results The overall proportion of male offspring among 865 live births to cohort mothers was 0.542. This was higher than the national male proportion of 0.514 (binomial test: p = 0.10. When both parents were in the cohort (n = 300, we found increased odds of a male birth with combined parents' enrollment PBB exposure ≥ the median concentrations (3 μg/L for mothers; 6 μg/L for fathers compared to combined parents' PBB exposure Conclusion This study adds to the body of literature on secondary sex ratio and exposure to environmental contaminants. In this population, combined parental exposure to PBBs or PCBs increased the odds of a male birth. Further research is needed to corroborate these findings and shed light on the biological mechanisms by which these types of chemicals may influence the secondary sex ratio.

  20. Natural mixtures of persistent organic pollutants (POPs) suppress ovarian follicle development, liver vitellogenin immunostaining and hepatocyte proliferation in female zebrafish (Danio rerio)

    Energy Technology Data Exchange (ETDEWEB)

    Kraugerud, Marianne, E-mail: Marianne.Kraugerud@nvh.no [Dept. of Basic Sciences and Aquatic Medicine, Norwegian School of Veterinary Science, POB 8146 Dep., 0033 Oslo (Norway); Doughty, Richard William, E-mail: vetrwdoughty@yahoo.co.uk [Sundveien 22, 2015 Leirsund (Norway); Lyche, Jan L., E-mail: Jan.Lyche@nvh.no [Dept. of Food Safety and Infection Biology, Norwegian School of Veterinary Science, POB 8146 Dep., 0033 Oslo (Norway); Berg, Vidar, E-mail: Vidar.Berg@nvh.no [Dept. of Food Safety and Infection Biology, Norwegian School of Veterinary Science, POB 8146 Dep., 0033 Oslo (Norway); Tremoen, Nina H., E-mail: Nina.Hardnes@nvh.no [Dept. of Production Animal Clinical Sciences, Norwegian School of Veterinary Science, POB 8146 Dep., 0033 Oslo (Norway); Alestrom, Peter, E-mail: Peter.Alestrom@nvh.no [Dept. of Basic Sciences and Aquatic Medicine, Norwegian School of Veterinary Science, POB 8146 Dep., 0033 Oslo (Norway); Aleksandersen, Mona, E-mail: Mona.Aleksandersen@nvh.no [Dept. of Basic Sciences and Aquatic Medicine, Norwegian School of Veterinary Science, POB 8146 Dep., 0033 Oslo (Norway); Ropstad, Erik, E-mail: Erik.Ropstad@nvh.no [Dept. of Production Animal Clinical Sciences, Norwegian School of Veterinary Science, POB 8146 Dep., 0033 Oslo (Norway)

    2012-07-15

    Persistent organic pollutants such as polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and dichlorodiphenyltrichloroethane (DDT) are present in high concentrations in livers of burbot (Lota lota) in Lake Mjosa, Norway. In order to assess effects of such pollutants on fish gonadal morphology, female zebrafish were exposed in two generations by food to mixtures of pollutants extracted from livers of burbot from Lake Mjosa (high and low dose) and Lake Losna, which represents background pollution, and compared to a control group. Ovarian follicle counts detected a significant decrease in late vitellogenic follicle stages in fish exposed to the Losna and the high concentrations of Mjosa mixtures in fish from the first generation. In addition, proliferation of granulosa cells, visualized by immunohistochemistry against proliferating cell nuclear antigen (PCNA), was decreased in all exposure groups in either early or late vitellogenic follicle stages compared to control. This was accompanied by increased apoptosis of granulosa cells. There was a decrease in proliferation of liver hepatocytes with exposure to both Mjosa mixtures. In addition, immunopositivity for vitellogenin in the liver was significantly lower in the Mjosa high group than in the control group. When analysing effects of parental exposure, fish with parents exposed to Mjosa high mixture had significantly higher numbers of perinucleolar follicles than fish with control parents. We conclude that long-term exposure of a real-life mixture of pollutants containing high- and background levels of chemicals supress ovarian follicle development, liver vitellogenin immunostaining intensity and hepatocyte proliferation in the zebrafish model.

  1. SIMPLE METHOD FOR ESTIMATING POLYCHLORINATED BIPHENYL CONCENTRATIONS ON SOILS AND SEDIMENTS USING SUBCRITICAL WATER EXTRACTION COUPLED WITH SOLID-PHASE MICROEXTRACTION. (R825368)

    Science.gov (United States)

    A rapid method for estimating polychlorinated biphenyl (PCB) concentrations in contaminated soils and sediments has been developed by coupling static subcritical water extraction with solid-phase microextraction (SPME). Soil, water, and internal standards are placed in a seale...

  2. Synthesis and Screening of Novel Substituted Biphenyl Proteomimetics as Potential Anti-Estrogenic Agents for the Treatment of Hormone-Responsive Breast Cancer

    National Research Council Canada - National Science Library

    Hanson, Robert N

    2005-01-01

    .... The specific aims involved preparing the requisite aryl halide and boronic acid intermediates, coupling to generate the small biphenyl library and evaluating the compounds in a competitive binding assay...

  3. The need and Potential of Biosensors to Detect Dioxins and Dioxin-Like Polychlorinated Biphenyls along the Milk, Eggs and Meat Food Chain

    NARCIS (Netherlands)

    Chobtang, J.; Boer, de I.J.M.; Hoogenboom, L.A.P.; Haasnoot, W.; Kijlstra, A.; Meerburg, B.G.

    2011-01-01

    Dioxins and dioxin-like polychlorinated biphenyls (DL-PCBs) are hazardous toxic, ubiquitous and persistent chemical compounds, which can enter the food chain and accumulate up to higher trophic levels. Their determination requires sophisticated methods, expensive facilities and instruments,

  4. Polychlorinated Biphenyls (PCBs) and Polybrominated Diphenol Ethers (PBDEs) in Current and Historical Samples of Avian Eggs from Nesting Sites in Buzzards Bay, MA, USA

    Science.gov (United States)

    We measured concentrations of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in eggs from breeding colonies in Buzzards Bay, MA, USA. Eggs from two piscivorous bird species, common (Sterna hirundo) and roseate (Sterna dougallii) terns, were collected...

  5. GRAVITY PIPELINE TRANSPORT FOR HARDENING FILLING MIXTURES

    Directory of Open Access Journals (Sweden)

    Leonid KROUPNIK

    2015-12-01

    Full Text Available In underground mining of solid minerals becoming increasingly common development system with stowing hardening mixtures. In this case the natural ore array after it is replaced by an artificial excavation of solidified filling mixture consisting of binder, aggregates and water. Such a mixture is prepared on the surface on special stowing complexes and transported underground at special stowing pipelines. However, it is transported to the horizons of a few kilometers, which requires a sustainable mode of motion of such a mixture in the pipeline. Hardening stowing mixture changes its rheological characteristics over time, which complicates the calculation of the parameters of pipeline transportation. The article suggests a method of determining the initial parameters of such mixtures: the status coefficient, indicator of transportability, coefficient of hydrodynamic resistance to motion of the mixture. These indicators characterize the mixture in terms of the possibility to transport it through pipes. On the basis of these indicators is proposed methodology for calculating the parameters of pipeline transport hardening filling mixtures in drift mode when traffic on the horizontal part of the mixture under pressure column of the mixture in the vertical part of the backfill of the pipeline. This technique allows stable operation is guaranteed to provide pipeline transportation.

  6. Predicting soil-water partitioning of polycyclic aromatic hydrocarbons and polychlorinated biphenyls by desorption with methanol-water mixtures at different temperatures.

    Science.gov (United States)

    Krauss, M; Wilcke, W

    2001-06-01

    We evaluated a method to determine organic carbon-normalized soil-water partition coefficients (Koc) of 20 PAHs and 12 PCBs by desorption in the presence of a cosolvent (methanol fractions of 0.1-0.9) and at different temperatures (20-80 degrees C). The Koc values, the deviation factor from ideal sorption alpha, and the desorption enthalpies delta Hdes were estimated by nonlinear regression of log Koc on the methanol fractions and on T. The Koc values of individual compounds varied up to a factor of 100 among the studied 11 urban soils. The calculated alpha and delta Hdes of individual compounds varied considerably among the soils (coefficients of variation 5-20% and 20-30%, respectively), alpha increased with increasing hydrophobicity of the compounds. A sequential extraction with four temperature/methanol fraction combinations followed by a nonlinear regression allowed for the direct determination of the Koc, alpha, and delta Hdes. The use of less temperature/methanol fraction combinations requires a suitable estimation of alpha and delta Hdes, as their choice may change the obtained Koc values by up to a factor of 10. The proposed method is suitable for a routine determination of Koc values of PAHs and PCBs for small soil samples (2-6 g) and low concentrations (down to 0.3 mg kg-1 of sigma 20 PAHs and 1.2 micrograms kg-1 of sigma 12 PCBs).

  7. Vibrational relaxation in OCS mixtures

    International Nuclear Information System (INIS)

    Simpson, C.J.S.M.; Gait, P.D.; Simmie, J.M.

    1976-01-01

    Experimental measurements are reported of vibrational relaxation times which may be used to show whether there is near resonant vibration-rotation energy transfer between OCS and H 2 , D 2 or HD. Vibrational relaxation times have been measured in OCS and OCS mixtures over the temperature range 360 to 1000 K using a shock tube and a laser schlieren system. The effectiveness of the additives in reducing the relaxation time of OCS is in the order 4 He 3 He 2 2 and HD. Along this series the effect of an increase in temperature changes from the case of speeding up the rate with 4 He to retarding it with D 2 , HD and H 2 . There is no measurable difference in the effectiveness of n-D 2 and o-D 2 and little, or no, difference between n-H 2 and p-H 2 . Thus the experimental results do not give clear evidence for rotational-vibration energy transfer between hydrogen and OCS. This contrasts with the situation for CO 2 + H 2 mixtures. (author)

  8. Supercritical Water Mixture (SCWM) Experiment

    Science.gov (United States)

    Hicks, Michael C.; Hegde, Uday G.

    2012-01-01

    The subject presentation, entitled, Supercritical Water Mixture (SCWM) Experiment, was presented at the International Space Station (ISS) Increment 33/34 Science Symposium. This presentation provides an overview of an international collaboration between NASA and CNES to study the behavior of a dilute aqueous solution of Na2SO4 (5% w) at near-critical conditions. The Supercritical Water Mixture (SCWM) investigation, serves as important precursor work for subsequent Supercritical Water Oxidation (SCWO) experiments. The SCWM investigation will be performed in DECLICs High Temperature Insert (HTI) for the purpose of studying critical fluid phenomena at high temperatures and pressures. The HTI includes a completely sealed and integrated test cell (i.e., Sample Cell Unit SCU) that will contain approximately 0.3 ml of the aqueous test solution. During the sequence of tests, scheduled to be performed in FY13, temperatures and pressures will be elevated to critical conditions (i.e., Tc = 374C and Pc = 22 MPa) in order to observe salt precipitation, precipitate agglomeration and precipitate transport in the presence of a temperature gradient without the influences of gravitational forces. This presentation provides an overview of the motivation for this work, a description of the DECLIC HTI hardware, the proposed test sequences, and a brief discussion of the scientific research objectives.

  9. The effect of dietary glycine on the hepatic tumor promoting activity of polychlorinated biphenyls (PCBs) in rats

    International Nuclear Information System (INIS)

    Bunaciu, Rodica Petruta; Tharappel, Job C.; Lehmler, Hans-Joachim; Kania-Korwel, Izabela; Robertson, Larry W.; Srinivasan, Cidambi; Spear, Brett T.; Glauert, Howard P.

    2007-01-01

    Polychlorinated biphenyls (PCBs) are ubiquitious lipophilic environmental pollutants. Some of the PCB congeners and mixtures of congeners have tumor promoting activity in rat liver. The mechanism of their activity is not fully understood and is likely to be multifactorial. The aim of this study was to investigate if the resident liver macrophages, Kupffer cells, are important in the promoting activity of PCBs. The hypothesis of this study was that the inhibition of Kupffer cell activity would inhibit hepatic tumor promotion by PCBs in rats. To test our hypothesis, we studied the effects of Kupffer cell inhibition by dietary glycine (an inhibitor of Kupffer cell secretory activity) in a rat two-stage hepatocarcinogenesis model using 2,2',4,4',5,5'-hexachlorobiphenyl (PCB-153, a non-dioxin-like PCB) or 3,3',4,4'-tetrachlorobiphenyl (PCB-77, a dioxin-like PCB) as promoters. Diethylnitrosamine (DEN, 150 mg/kg) was administered to female Sprague-Dawley rats, which were then placed on an unrefined diet containing 5% glycine (or casein as nitrogen control) starting two weeks after DEN administration. On the third day after starting the diets, rats received PCB-77 (300 μmol/kg), PCB-153 (300 μmol/kg), or corn oil by i.p. injection. The rats received a total of 4 PCB injections, administered every 14 days. The rats were euthanized on the 10th day after the last PCB injection, and the formation of altered hepatic foci expressing placental glutathione S-transferase (PGST) and the rate of DNA synthesis in these foci and in the normal liver tissue were determined. Glycine did not significantly affect foci number or volume. PCB-153 did not significantly increase the focal volume, but increased the number of foci per liver, but only in the rats not fed glycine; PCB-77 increased both the foci number and their volume in both glycine-fed and control rats. Glycine did not alter the PCB content of the liver, but did increase the activity of 7-benzyloxyresorufin O-dealkylase (BROD

  10. Changes of polybrominated diphenyl ethers and polychlorinated biphenyls in surface soils from urban agglomeration of the Yangtze River Delta, in China between 2003 and 2012.

    Science.gov (United States)

    Shi, Shuang-Xin; Huang, Ye-Ru; Zhou, Li; Zhang, Li-Fei; Dong, Liang; Yang, Wen-Long; Zhang, Xiu-Lan

    2015-07-01

    Surface soil samples were collected from urban agglomeration of the Yangtze River Delta (YRD), China in 2003 and 2012, respectively. Polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) were analyzed to determine if there were any changes in their levels and compositional profiles between the two sampling years. The concentrations of Σ8PBDEs ranged from 0.553 to 13.0 μg kg(-1)(with the mean of 3.31 μg kg(-1)) in the 2003 samples and from 1.01 to 43.2 μg/kg (with the mean of 10.0 μg kg(-1)) in the 2012 samples. The concentrations of Σ32PCBs ranged from 0.301 to 3.29 μg kg(-1)(with the mean of 1.01 μg kg(-1)) in the 2003 samples and from 0.205 to 3.96 μg/kg (with the mean of 0.991 μg kg(-1)) in the 2012 samples. The comparisons between the 2012 and 2003 data showed that PBDEs concentrations increased over the years, but PCB concentrations did not change much. BDE-209 was the major BDE congener in both the 2003 and 2012 samples, indicating that the dominant PBDE mixture production and usage in the YRD had been the commercial deca-BDE mixture. Investigation of the PBDE congener profiles indicated that there had been new input of octa-BDEs in this region in recent years. Little change was found for the pattern of PCBs congener profiles between 2 years' samples. As such, spatial distributions of PBDEs or PCBs in surface soil samples reflected a gradient (from high to low) from the central cities out to rural areas in both the 2003 and 2012 data. In addition, high concentrations of PBDEs were observed in the industrial and residential areas, whereas high concentrations of PCBs were only observed in the industrial areas.

  11. Bis(μ-biphenyl-2,2′-dicarboxylatobis[(2,2′-bipyridinecopper(II

    Directory of Open Access Journals (Sweden)

    Zhe An

    2009-04-01

    Full Text Available The title compound, [Cu2(C14H8O42(C10H8N22], was obtained by solvothermal synthesis. The CuII atom is coordinated by one chelating 2,2′-bipyridine ligand and two carboxyl groups from different biphenyl-2,2′-dicarboxylate ligands, leading to a distorted octahedral environment. Each carboxylate group makes one short Cu—O bond [1.9608 (14 and 1.9701 (14 Å] and one longer Cu—O contact [2.4338 (17 and 2.5541 (17 Å] to each CuII atom. The biphenyl-2,2′-dicarboxylate ligands bridge between CuII atoms, forming a dinuclear complex around a crystallographic inversion centre.

  12. C-Aryl glucoside SGLT2 inhibitors containing a biphenyl motif as potential anti-diabetic agents.

    Science.gov (United States)

    Ding, Yuyang; Mao, Liufeng; Xu, Dengfeng; Xie, Hui; Yang, Ling; Xu, Hongjiang; Geng, Wenjun; Gao, Yong; Xia, Chunguang; Zhang, Xiquan; Meng, Qingyi; Wu, Donghai; Zhao, Junling; Hu, Wenhui

    2015-07-15

    A series of highly active C-aryl glucoside SGLT2 inhibitors containing a biphenyl motif were designed and synthesized for biological evaluation. Among the compounds tested, compound 16l demonstrated high inhibitory activity against SGLT2 (IC50=1.9 nM) with an excellent pharmacokinetic profile. Further study indicated that the in vivo efficacy of compound 16l was comparable to that of dapagliflozin, suggesting that further development would be worthwhile. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Congener-specific polychlorinated biphenyl patterns in eggs of aquatic birds from the lower Laguna Madre, Texas

    Science.gov (United States)

    Mora, Miguel A.

    1996-01-01

    Eggs from four aquatic bird species nesting in the Lower Laguna Madre, Texas, were collected to determine differences and similarities in the accumulation of congener-specific polychlorinated biphenyls (PCBs) and to evaluate PCB impacts on reproduction. Because of the different toxicities of PCB congeners, it is important to know which congeners contribute most to total PCBs. The predominant PCB congeners were 153, 138, 180, 110, 118, 187, and 92. Collectively, congeners 153, 138, and 180 accounted for 26 to 42% of total PCBs. Congener 153 was the most abundant in Caspian terns (Sterna caspia) and great blue herons (Ardea herodias) and congener 138 was the most abundant in snowy egrets (Egretta thula) and tricolored herons (Egretta tricolor). Principal component analysis indicated a predominance of higher chlorinated biphenyls in Caspian terns and great blue herons and lower chlorinated biphenyls in tricolored herons. Snowy egrets had a predominance of pentachlorobiphenyls. These results suggest that there are differences in PCB congener patterns in closely related species and that these differences are more likely associated with the species' diet rather than metabolism. Total PCBs were significantly greater (p birds from the Lower Laguna Madre were below concentrations known to affect bird reproduction.

  14. Magnetoelectrochemistry of 4,4'-bis(dimethylamino)biphenyl and 4,4'-dinitrobiphenyl azacrown macrocyclic lactams

    Energy Technology Data Exchange (ETDEWEB)

    Domenech, Antonio [Departament de Quimica Analitica, Universitat de Valencia, Dr. Moliner 50, 46100 Burjassot, Valencia (Spain); Costero, Ana Maria; Banuls, Maria Jose; Aurell, Maria Jose [Departament de Quimica Organica, Universitat de Valencia, Dr. Moliner 50, 46100 Burjassot, Valencia (Spain)

    2005-07-25

    The voltammetric behaviour at carbon fibre microelectrodes under the application of static magnetic fields of two series of macrolactams containing in their structure 4,4'-bis(dimethylamino)biphenyl or 4,4'-dinitrobiphenyl groups in MeCN solution is described. The response of 4,4'-dinitrobiphenyl receptors is dominated by two successive one-electron reduction processes at -0.9 and -1.6 V versus AgCl/Ag. 4,4'-bis(dimethylamino)biphenyl-containing receptors display two one-electron oxidations above +0.8 and +1.0 V. In both cases, a dihedral/planar interconversion precedes the second electron transfer step. Upon application of moderate (0.05-0.2 T) static magnetic fields to the electrochemical cell, the rate of such dihedral/planar interconversion is lowered for both the reduction of 4,4'-dinitrobiphenyl receptors and the oxidation of 4,4'-bis(dimethylamino)biphenyl lactams. The electrochemical response of N-methylated receptors, for which different cisoid-cisoid, cisoid-transoid, and transoid-transoid forms exist, exhibits a significant peak splitting that can be associated to the presence of such conformational isomers. Application of magnetic fields produces a relative enhancement of some peaks that can be interpreted in terms of differential magnetoconvection involving such conformational isomers. (author)

  15. Photo/electroluminescence properties of an europium (III) complex doped in 4,4'-N,N'-dicarbazole-biphenyl matrix

    International Nuclear Information System (INIS)

    Zhou Yonghui; Zhou Liang; Wu, Jing; Li, Hong-Yan; Zheng Youxuan; You Xiaozeng; Zhang Hongjie

    2010-01-01

    The photoluminescence properties of one europium complex Eu(TFNB) 3 Phen (TFNB = 4,4,4-trifluoro-1-(naphthyl)-1,3-butanedione, Phen = 1,10-phenanthroline) doped in a hole-transporting material CBP (4,4'-N,N'-dicarbazole-biphenyl) films were studied. A series of organic light-emitting devices (OLEDs) using Eu(TFNB) 3 Phen as the emitter were fabricated with a multilayer structure of indium tin oxide, 250 Ω/square)/TPD (N,N'-diphenyl-N,N'-bis(3-methyllphenyl)-(1,1'-biphenyl)-4,4'-diamine, 50 nm)/Eu(TFNB) 3 phen (x): CBP (4,4'-N,N'-dicarbazole-biphenyl, 45 nm)/BCP (2,9-dimethyl-4,7-diphenyl-l,10 phenanthroline, 20 nm)/AlQ (tris(8-hydroxy-quinoline) aluminium, 30 nm)/LiF (1 nm)/Al (100 nm), where x is the weight percentage of Eu(TFNB) 3 phen doped in the CBP matrix (1-6%). A red emission at 612 nm with a half bandwidth of 3 nm, characteristic of Eu(III) ion, was observed with all devices. The device with a 3% dopant concentration shows the maximum luminance up to 1169 cd/m 2 (18 V) and the device with a 5% dopant concentration exhibits a current efficiency of 4.46 cd/A and power efficiency of 2.03 lm/W. The mechanism of the electroluminescence was also discussed.

  16. Mixtures and their risk assessment in toxicology.

    Science.gov (United States)

    Mumtaz, Moiz M; Hansen, Hugh; Pohl, Hana R

    2011-01-01

    For communities generally and for persons living in the vicinity of waste sites specifically, potential exposures to chemical mixtures are genuine concerns. Such concerns often arise from perceptions of a site's higher than anticipated toxicity due to synergistic interactions among chemicals. This chapter outlines some historical approaches to mixtures risk assessment. It also outlines ATSDR's current approach to toxicity risk assessment. The ATSDR's joint toxicity assessment guidance for chemical mixtures addresses interactions among components of chemical mixtures. The guidance recommends a series of steps that include simple calculations for a systematic analysis of data leading to conclusions regarding any hazards chemical mixtures might pose. These conclusions can, in turn, lead to recommendations such as targeted research to fill data gaps, development of new methods using current science, and health education to raise awareness of residents and health care providers. The chapter also provides examples of future trends in chemical mixtures assessment.

  17. Conductivity and applications of Li-biphenyl-1,2-dimethoxyethane solution for lithium ion batteries

    Institute of Scientific and Technical Information of China (English)

    Geng Chu; Bo-Nan Liu; Fei Luo; Wen-Jun Li; Hao Lu; Li-Quan Chen; Hong Li

    2017-01-01

    The total conductivity of Li-biphenyl-l,2-dimethoxyethane solution (LixBp(DME)9.65,Bp =biphenyl,DME =1,2-dimethoxyethane,x =0.25,0.50,1.00,1.50,2.00) is measured by impedance spectroscopy at a temperature range from 0 ℃C to 40 ℃C.The Li1.50Bp(DME)9.65 has the highest total conductivity 10.7 mS/cm.The conductivity obeys Arrhenius law with the activation energy (Ea(x=0.50) =0.014 eV,Ea(x=1.00) =0.046 eV).The ionic conductivity and electronic conductivity of LixBp(DME)9.65 solutions are investigated at 20 ℃C using the isothermal transient ionic current (ITIC) technique with an ion-blocking stainless steal electrode.The ionic conductivity and electronic conductivity of Li1.00Bp(DME)9.65 are measured as 4.5 mS/cm and 6.6 mS/cm,respectively.The Li1.00Bp(DME)9.65 solution is tested as an anode material of half liquid lithium ion battery due to the coexistence of electronic conductivity and ionic conductivity.The lithium iron phosphate (LFP) and Li1.5Al0.5Ti1.5(PO4)3 (LATP) are chosen to be the counter electrode and electrolyte,respectively.The assembled cell is cycled in the voltage range of 2.2 V-3.75 V at a current density of 50 mA/g.The potential of Lit.00Bp(DME)9.65 solution is about 0.3 V vs.Li+/Li,which indicates the solution has a strong reducibility.The Li1.00Bp(DME)9.65 solution is also used to prelithiate the anode material with low first efficiency,such as hard carbon,soft carbon and silicon.

  18. Identification of a novel dimethoxylated polybrominated biphenyl bioaccumulating in marine mammals

    Energy Technology Data Exchange (ETDEWEB)

    Marsh, G.; Athanasiadou, M.; Bergman, Aa.; Athanassiadis, I. [Department of Environmental Chemistry, Stockholm (Sweden); Endo, Tetsuya [Health Sciences Univ. of Hokkaido (Japan). Fac. of Pharmaceutical Sciences; Haraguchi, Koichi [Daiichi College of Pharmaceutical Sciences, Fukuoka (Japan)

    2004-09-15

    The screening of persistent halogenated organic pollutants has in recent years ended up with findings of numerous compounds being natural products. These compounds have preferably been reported from the marine environment and comprise, several hydroxylated and methoxylated polybrominated diphenyl ethers (OH-PBDEs and MeO-PBDEs) including monochlorinated ditto, a dimethoxylated polybrominated diphenyl ether i.e. 2',6-dimethoxy-2,3',4,5'-tetrabromodiphenyl ether, four halogenated dimethylated bipyrroles (HDBPs) with a 2,2'-bipyrrole backbone, a heptachlorinated 1,2'-bipyrrole i.e. heptachloro-1'-methyl-1,2'-bipyrrole (Q1)6 and a halogenated monoterpene holding two bromine and three chlorine atoms. We have taken interest in an organobrominated compound with an unknown structure but with a molecule ion of m/z = 526 and a four bromine isotope pattern according to mass spectrometry (MS), detected in marine mammal samples of which the majority were collected from Japanese coastal waters. This compound has recently been reported from several marine mammals collected on the Southern hemisphere, but neither the chemical structure nor the type of substance group were established. We here report the structure of this organobrominated compound, a dimethoxylated polybrominated biphenyl, which likely is of natural origin. The identification was done by the comparison of relative retention time (RRT) on two GC columns with different polarities and by comparing mass spectra from three different ionization techniques i.e. PICI, ECNI and EI, of the unknown compound from the samples with an authentic reference compound. Levels of the novel dimethoxylated polybrominated biphenyl are reported as well as the levels (for comparison) of some other known polybrominated compounds, both brominated flame retardants (BFRs) and natural products i.e. BDE-47, BDE-99, BDE-100, BDE-153, BDE-154, BDE-183, 1,2,5,6,9,10- hexabromocyclododecane (HBCDD), 6-MeO-BDE-47, 2

  19. Efficient radiative transfer in dust grain mixtures

    OpenAIRE

    Wolf, S.

    2002-01-01

    The influence of a dust grain mixture consisting of spherical dust grains with different radii and/or chemical composition on the resulting temperature structure and spectral energy distribution of a circumstellar shell is investigated. The comparison with the results based on an approximation of dust grain parameters representing the mean optical properties of the corresponding dust grain mixture reveal that (1) the temperature dispersion of a real dust grain mixture decreases substantially ...

  20. Some properties of explosive mixtures containing peroxides

    Energy Technology Data Exchange (ETDEWEB)

    Zeman, Svatopluk [Institute of Energetic Materials, Faculty of Chemical Technology, University of Pardubice, CZ-532 10 Pardubice (Czech Republic)], E-mail: svatopluk.zeman@upce.cz; Trzcinski, Waldemar A. [Institute of Chemistry, Military University of Technology, PL-00-908 Warsaw 49 (Poland); Matyas, Robert [Institute of Energetic Materials, Faculty of Chemical Technology, University of Pardubice, CZ-532 10 Pardubice (Czech Republic)

    2008-06-15

    This study concerns mixtures of triacetone triperoxide (3,3,6,6,9,9-hexamethyl-1,2,4,5,7,8-hexoxonane, TATP) and ammonium nitrate (AN) with added water (W), as the case may be, and dry mixtures of TATP with urea nitrate (UN). Relative performances (RP) of the mixtures and their individual components, relative to TNT, were determined by means of ballistic mortar. The detonation energies, E{sub 0}, and detonation velocities, D, were calculated for the mixtures studied by means of the thermodynamic code CHEETAH. Relationships have been found and are discussed between the RP and the E{sub 0} values related to unit volume of gaseous products of detonation of these mixtures. These relationships together with those between RP and oxygen balance values of the mixtures studied indicate different types of participation of AN and UN in the explosive decomposition of the respective mixtures. Dry TATP/UN mixtures exhibit lower RP than analogous mixtures TATP/AN containing up to 25% of water. Depending on the water content, the TATP/AN mixtures possess higher detonability values than the ANFO explosives. A semi-logarithmic relationship between the D values and oxygen coefficients has been derived for all the mixtures studied at the charge density of 1000 kg m{sup -3}. Among the mixtures studied, this relationship distinguishes several samples of the type of 'tertiary explosives' as well as samples that approach 'high explosives' in their performances and detonation velocities.

  1. Method for separating gaseous mixtures of isotopes

    International Nuclear Information System (INIS)

    Neimann, H.J.; Schuster, E.; Kersting, A.

    1976-01-01

    A gaseous mixture of isotopes is separated by laser excitation of the isotope mixture with a narrow band of wavelengths, molecularly exciting mainly the isotope to be separated and thereby promoting its reaction with its chemical partner which is excited in a separate chamber. The excited isotopes and the chemical partner are mixed, perhaps in a reaction chamber to which the two excited components are conducted by very short conduits. The improvement of this method is the physical separation of the isotope mixture and its partner during excitation. The reaction between HCl and the mixture of 238 UF 6 and 235 UF 6 is discussed

  2. Shear viscosity of liquid mixtures: Mass dependence

    International Nuclear Information System (INIS)

    Kaushal, Rohan; Tankeshwar, K.

    2002-06-01

    Expressions for zeroth, second, and fourth sum rules of transverse stress autocorrelation function of two component fluid have been derived. These sum rules and Mori's memory function formalism have been used to study shear viscosity of Ar-Kr and isotopic mixtures. It has been found that theoretical result is in good agreement with the computer simulation result for the Ar-Kr mixture. The mass dependence of shear viscosity for different mole fraction shows that deviation from ideal linear model comes even from mass difference in two species of fluid mixture. At higher mass ratio shear viscosity of mixture is not explained by any of the emperical model. (author)

  3. Evaluation of mastic in bituminous mixtures

    OpenAIRE

    Silva, Hugo Manuel Ribeiro Dias da; Pais, Jorge C.; Pereira, Paulo A. A.

    2002-01-01

    The efficiency of the asphalt-aggregate bond is one of the key factors which affects the mechanical resistance of bituminous mixtures and a better understanding of its performance allows the behaviour of mixture to be more accurately predicted. The asphalt-aggregate bond depends on the properties of the mastic and the mixture of fine aggregate and bitumen which bonds itself to the larger sized particles within the bituminous mixture. This mastic plays an im-portant role in the asphalt-aggr...

  4. Shear viscosity of liquid mixtures Mass dependence

    CERN Document Server

    Kaushal, R

    2002-01-01

    Expressions for zeroth, second, and fourth sum rules of transverse stress autocorrelation function of two component fluid have been derived. These sum rules and Mori's memory function formalism have been used to study shear viscosity of Ar-Kr and isotopic mixtures. It has been found that theoretical result is in good agreement with the computer simulation result for the Ar-Kr mixture. The mass dependence of shear viscosity for different mole fraction shows that deviation from ideal linear model comes even from mass difference in two species of fluid mixture. At higher mass ratio shear viscosity of mixture is not explained by any of the emperical model.

  5. Exposure to polychlorinated biphenyls and the thyroid gland – examining and discussing possible longitudinal health effects in humans

    Energy Technology Data Exchange (ETDEWEB)

    Gaum, Petra M., E-mail: pgaum@ukaachen.de [Institute for Occupational and Social Medicine, RWTH Aachen University, Pauwelsstraße 30, D-52074 Aachen (Germany); Lang, Jessica; Esser, André; Schettgen, Thomas [Institute for Occupational and Social Medicine, RWTH Aachen University, Pauwelsstraße 30, D-52074 Aachen (Germany); Neulen, Joseph [Clinic for Gynaecological Endocrinology and Reproductive Medicine, RWTH Aachen University, Pauwelsstraße 30, D-52074 Aachen (Germany); Kraus, Thomas; Gube, Monika [Institute for Occupational and Social Medicine, RWTH Aachen University, Pauwelsstraße 30, D-52074 Aachen (Germany)

    2016-07-15

    Background: Many previous studies have dealt with the effect of polychlorinated biphenyls (PCBs) on the thyroid gland, but their findings are inconsistent. One problem of these studies has been their use of cross-sectional designs. Objectives: The aim of the current study is to investigate longitudinal effects of PCBs on the thyroid gland, focusing on: morphological changes in thyroid tissue (i.e. thyroid volume), changes in thyroid hormones and in thyroid antibodies. Methods: A total of 122 individuals (M{sub age}=44.7) were examined over a period of four years (t{sup 1} until t{sup 4}). Medical history was collected via interviews, an ultrasound examination was performed and blood samples were taken to determine plasma PCB levels, thyroid stimulating hormone (TSH), free triiodthyronine (fT3), free thyroxine (fT4), thyroid peroxidase antibodies (TPOab), thyreoglobulin antibodies (TGab) and thyroid-stimulating hormone receptor antibodies (TSHRab). Rank correlation coefficients and mixed effect models were performed controlling for age and total lipids. Results: There were negative correlations between higher chlorinated biphenyls and fT3, cross-sectionally as well as longitudinally. We also found an interaction effect of higher-chlorinated PCBs over time for fT4 as well as TSHRab. In case of high exposure, a decrease in fT4 and an increase in TSHRab level were found over time. In regards to the other variables, our findings yielded no clear results in the examined time period. Conclusion: This is the first study to shows a PCB-related effect on fT3, fT4 and TSHRab over a four year period. The data also suggest that morphological and antibody findings remain inconsistent and do not allow for unambiguous interpretation. - Highlights: • This is a longitudinal study which includes data from four cross sections. • Higher-chlorinated biphenyls are negatively correlated with fT3. • There are interactions of time and higher-chlorinated biphenyls to TSHRab and fT4.

  6. Deciding which chemical mixtures risk assessment methods work best for what mixtures

    International Nuclear Information System (INIS)

    Teuschler, Linda K.

    2007-01-01

    The most commonly used chemical mixtures risk assessment methods involve simple notions of additivity and toxicological similarity. Newer methods are emerging in response to the complexities of chemical mixture exposures and effects. Factors based on both science and policy drive decisions regarding whether to conduct a chemical mixtures risk assessment and, if so, which methods to employ. Scientific considerations are based on positive evidence of joint toxic action, elevated human exposure conditions or the potential for significant impacts on human health. Policy issues include legislative drivers that may mandate action even though adequate toxicity data on a specific mixture may not be available and risk assessment goals that impact the choice of risk assessment method to obtain the amount of health protection desired. This paper discusses three important concepts used to choose among available approaches for conducting a chemical mixtures risk assessment: (1) additive joint toxic action of mixture components; (2) toxicological interactions of mixture components; and (3) chemical composition of complex mixtures. It is proposed that scientific support for basic assumptions used in chemical mixtures risk assessment should be developed by expert panels, risk assessment methods experts, and laboratory toxicologists. This is imperative to further develop and refine quantitative methods and provide guidance on their appropriate applications. Risk assessors need scientific support for chemical mixtures risk assessment methods in the form of toxicological data on joint toxic action for high priority mixtures, statistical methods for analyzing dose-response for mixtures, and toxicological and statistical criteria for determining sufficient similarity of complex mixtures

  7. Thermodynamics of mixtures containing amines

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Juan Antonio [G.E.T.E.F. Dpto Termodinamica y Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, Valladolid 47071 (Spain)], E-mail: jagl@termo.uva.es; Mozo, Ismael; Garcia de la Fuente, Isaias; Cobos, Jose Carlos [G.E.T.E.F. Dpto Termodinamica y Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, Valladolid 47071 (Spain); Riesco, Nicolas [Department of Chemical Engineering, Loughborough University, Loughborough, LE113TU Leicestershire (United Kingdom)

    2008-01-30

    Mixtures with dimethyl or trimethylpyridines and alkane, aromatic compound or 1-alkanol have been examined using different theories: DISQUAC, Flory, the concentration-concentration structure factor, S{sub CC}(0), or the Kirkwood-Buff formalism. DISQUAC represents fairly well the available experimental data, and improves theoretical calculations from Dortmund UNIFAC. Two important effects have been investigated: (i) the effect of increasing the number of methyl groups attached to the aromatic ring of the amine; (ii) the effect of modifying the position of the methyl groups in this ring. The molar excess enthalpy, H{sup E}, and the molar excess volume, V{sup E}, decrease in systems with alkane or methanol as follows: pyridine > 3-methylpyridine > 3,5-dimethylpyridine and pyridine > 2-methylpyridine > 2,4-dimethylpyridine > 2,4,6-trimethylpyridine, which has been attributed to a weakening of the amine-amine interactions in the same sequences. This is in agreement with the relative variation of the effective dipole moment, {mu}-bar, and of the differences between the boiling temperature of a pyridine base and that of the homomorphic alkane. For heptane solutions, the observed H{sup E} variation, H{sup E} (3,5-dimethylpyridine) > H{sup E} (2,4-dimethylpyridine) > H{sup E} (2,6-dimethylpyridine), is explained similarly. Calculations on the basis of the Flory model confirm that orientational effects become weaker in systems with alkane in the order: pyridine > methylpyridine > dimethylpyridine > trimethylpyridine. S{sub CC}(0) calculations show that steric effects increase with the number of CH{sub 3}- groups in the pyridine base, and that the steric effects exerted by methyl groups in positions 2 and 6 are higher than when they are placed in positions 3 and 5. The hydrogen bond energy in methanol mixtures is independent of the pyridine base, and it is estimated to be -35.2 kJ mol{sup -1}. Heterocoordination in these solutions is due in part to size effects. Their

  8. Polychlorinated biphenyl concentrations in pooled serum from people in different age groups from five Chinese cities.

    Science.gov (United States)

    Wang, Qinghua; Yuan, Haodong; Jin, Jun; Li, Peng; Ma, Yulong; Wang, Ying

    2018-05-01

    Polychlorinated biphenyl (PCB) concentrations in human serum samples pooled by donor age and sex (≥60, 50-59, 40-49, 30-39, and 20-29 years old) were determined. The pooled samples were supplied by hospitals in five Chinese cities, which were Yitong (Jilin Province), Weifang (Shandong Province), Ganzi (Sichuan Province), Huaihua (Hunan Province), and Lingshui (Hainan Province). The total PCB concentrations were relatively low compared with concentrations that have been found in other parts of the world. Pentachlorobiphenyls were the dominant PCBs. The total PCB concentrations and the concentrations of most of the pentachlorobiphenyl congeners were slightly higher in the samples from younger donors than in the samples from older donors. The results indicated there is a new source of PCBs in China. Heptachlorobiphenyls in Lingshui may have been transported from Vietnam. Statistical analysis showed that young and old people had been exposed to different sources of PCBs. PCB 126 contributed more than the other dioxin-like PCBs to the total toxic equivalents when the samples were examined as a whole or by city, and the total toxic equivalents were higher in younger people than in older people for the whole sample set and for the Yitong samples. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Seasonal air-water exchange fluxes of polychlorinated biphenyls in the Hudson River Estuary

    International Nuclear Information System (INIS)

    Yan Shu; Rodenburg, Lisa A.; Dachs, Jordi; Eisenreich, Steven J.

    2008-01-01

    Polychlorinated biphenyls (PCBs) were measured in the air and water over the Hudson River Estuary during six intensive field campaigns from December 1999 to April 2001. Over-water gas-phase ΣPCB concentrations averaged 1100 pg/m 3 and varied with temperature. Dissolved-phase ΣPCB concentrations averaged 1100 pg/L and displayed no seasonal trend. Uncertainty analysis of the results suggests that PCBs with 5 or fewer chlorines exhibited net volatilization. The direction of net air/water exchange could not be determined for PCBs with 6 or more chlorines. Instantaneous net fluxes of ΣPCBs ranged from +0.2 to +630 ng m -2 d -1 . Annual fluxes of ΣPCBs were predicted from modeled gas-phase concentrations, measured dissolved-phase concentrations, daily surface water temperatures and wind speeds. The net volatilization flux was +62 μg m -2 yr -1 , corresponding to an annual loss of +28 kg/yr of ΣPCBs from the Hudson River Estuary for the year of 2000. - Investigation of the air-water exchange of PCBs in the Hudson River Estuary suggests that PCBs with 5 or fewer chlorines undergo net volatilization

  10. Combined effect of microwave and activated carbon on the remediation of polychlorinated biphenyl-contaminated soil.

    Science.gov (United States)

    Liu, Xitao; Yu, Gang

    2006-04-01

    The application of microwave and activated carbon for the treatment of polychlorinated biphenyl (PCB) contaminated soil was explored in this study with a model compound of 2,4,5-trichlorobiphenyl (PCB29). PCB-contaminated soil was treated in a quartz reactor by microwave irradiation at 2450MHz with the addition of granular activated carbon (GAC). In this procedure, GAC acted as microwave absorbent for reaching high temperature and reductant for dechlorination. A sheltered type-K thermocouple was applied to record the temperature rising courses. It was shown that the addition of GAC could effectively promote the temperature rising courses. The determination of PCB residues in soil by gas chromatography (GC) revealed that rates of PCB removal were highly dependent on microwave power, soil moisture content, and the amount of GAC added. GC with mass spectrum (MS) detector and ion chromatography were employed for the analysis of degradation intermediates and chlorine ions, respectively. It was suggested that microwave irradiation with the assistance of activated carbon might be a potential technology for the remediation of PCB-contaminated soil.

  11. Remediation of soils contaminated with polychlorinated biphenyls by microwave-irradiated manganese dioxide

    International Nuclear Information System (INIS)

    Huang Guanyi; Zhao Ling; Dong Yuanhua; Zhang Qin

    2011-01-01

    The removal of polychlorinated biphenyls (PCBs) using microwave-irradiated manganese dioxide (MnO 2 ) in PCB-contaminated soils under different conditions is investigated. The removal of PCB77 in two actual soil samples exhibits strong pH-dependent behavior, and the removal efficiency is higher in acidic soil (Ali-Perudic Ferrosols) than that in neutral soil (Udic Argosols). The removal kinetics of PCB77 using microwave-irradiated MnO 2 under different experimental conditions fits a pseudo-first-order kinetic model well. Both the removal efficiency and the kinetic constant (k) values of PCB77 in Ali-Perudic Ferrosols considerably increase, although in a nonlinear fashion, as the initial amount of MnO 2 is increased, as the treated soil mass is increased, and as the microwave power is increased. The reactivity of three PCBs (PCB28, PCB77, and PCB118) did not present as a function of the degree of chlorination in the reaction with microwave-irradiated MnO 2 . The pronounced removal of three PCBs in contaminated soil (all above 95%) indicates that MnO 2 in combination with microwave irradiation is promising for technological applications that seek to remediate sites critically polluted with PCBs.

  12. Method and means for filtering polychlorinated biphenyls from a gas stream

    International Nuclear Information System (INIS)

    Sowinski, R.F.

    1992-01-01

    This patent describes a method of filtering, adjacent to an end user-customer's residence or business in which at least a single gas appliance is located, a natural gas stream in which polychlorinated biphenyls (PCB's) and degraded PCB products have been concentrated at sufficient levels to be a health threat in a natural gas gathering and distributing network. It comprises: introducing the natural gas stream to a filter selected from a group that includes impingement, absorbing and adsorbing media whereby PCB's and degraded PCB products concentrated in the gas stream at sufficient levels to be a health threat by a periodic loading of the natural gas within the gathering and distributing network, are filtered from the gas stream and captured irrespective of mode of transport, passing the filtered natural gas stream to the customer's gas appliance wherein safe use of the energy associated with the stream occurs; periodically and safely removing the filter, inserting a new filter in place of the removed filter

  13. The uridine diphosphate glucuronosyltransferases: quantitative structure-activity relationships for hydroxyl polychlorinated biphenyl substrates

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Degao [Dalian University of Technology, Department of Environmental Science and Technology, Dalian (China)

    2005-10-01

    Quantitative structure-activity relationships (QSARs), which relate the glucuronidation of hydroxyl polychlorinated biphenyls (OH-PCBs) - catalyzed by the uridine diphosphate glucuronosyltransferases (UGTs) - to their physicochemical properties and molecular structural parameters, can be used to predict the rate constants and interpret the mechanism of glucuronidation. In this study, QSARs have been developed that use 23 semi-empirical calculated quantum chemical descriptors to predict the logarithms of the constants 1/K{sub m} and V{sub max}, related to enzyme kinetics. A partial least squares regression method was used to select the optimal set of descriptors to minimize the multicollinearity between the descriptors, as well as to maximize the cross-validated coefficient (Q{sup 2} {sub cum}) values. The key descriptors affecting log(1/K{sub m}) were E{sub lumo}- E{sub homo} (the energy gap between the lowest unoccupied molecular orbital and the highest occupied molecular orbital) and q{sub C}{sup -} (the largest negative net atomic charge on a carbon atom), while the key descriptors affecting log V{sub max} were the polarizability {alpha}, the Connolly solvent-excluded volume (CSEV), and logP (the logarithm of the partition coefficient for octanol/water). From the results obtained it can be concluded that hydrophobic and electronic aspects of OH-PCBs are important in the glucuronidation of OH-PCBs. (orig.)

  14. Persistent or not persistent? Polychlorinated biphenyls are readily depurated by grizzly bears (Ursus arctos horribilis).

    Science.gov (United States)

    Christensen, Jennie R; Letcher, Robert J; Ross, Peter S

    2009-10-01

    Major pharmacokinetic processes influencing polychlorinated biphenyl (PCB) accumulation in mammals include uptake, biotransformation, respiration, and excretion. We characterized some of the factors underlying PCB accumulation/loss by evaluating PCB concentrations and patterns in pre- and posthibernation grizzly bears (Ursus arctos horribilis) and their prey. The PCB congeners with vicinal meta- and para-chlorine unsubstituted hydrogen positions consistently showed loss both before and during hibernation, supporting the idea of a dominant role for biotransformation. Retention of all other studied congeners relative to that of PCB 194 varied widely (from bears do not eat or excrete. We estimate that grizzly bears retain less than 10% of total PCBs taken up from their diet. Our results suggest that for grizzly bears, depuration of PCBs via biotransformation is important (explaining approximately 40% of loss), but that nonbiotransformation processes, such as excretion, may be more important (explaining approximately 60% of loss). These findings, together with the approximately 91% loss of the persistent PCB 153 congener relative to PCB 194 in grizzly bears, raise important questions about how one defines persistence of PCBs in wildlife and may have bearing on the interpretation of food-web biomagnification studies.

  15. Determination of non-ortho polychlorinated biphenyls in environmental Standard Reference Materials.

    Science.gov (United States)

    Brubaker, W W; Schantz, M M; Wise, S A

    2000-07-01

    The concentrations of three non-ortho ("coplanar") polychlorinated biphenyls, 3,3',4,4'-tetrachlorobiphenyl (IUPAC PCB 77), 3,3',4,4',5-pentachlorobiphenyl (IUPAC PCB 126), and 3,3',4,4',5,5'-hexachlorobiphenyl (IUPAC PCB 169), were determined in five NIST Standard Reference Materials (SRMs) of environmental and biological interest. The measured levels were approximately between (0.2 to 1.3) ng/g in SRM 1588a (Organics in Cod Liver Oil), (0.3 to 9) ng/g in SRM 1944 (New York/New Jersey Waterway Sediment), (0.2 to 0.4) ng/g in SRM 1945 (Organics in Whale Blubber), (1 to 18) ng/g in SRM 2974 (Organics in Freeze-dried Mussel Tissue [Mytilus edulis]), and (0.1 to 0.4) ng/g in candidate SRM 1946 (Lake Superior Fish Tissue). PCB 169 was present at < 0.1 ng/g in SRMs 1944 and 2974.

  16. Forecasting long-range atmospheric transport episodes of polychlorinated biphenyls using FLEXPART

    Science.gov (United States)

    Halse, Anne Karine; Eckhardt, Sabine; Schlabach, Martin; Stohl, Andreas; Breivik, Knut

    2013-06-01

    The analysis of concentrations of persistent organic pollutants (POPs) in ambient air is costly and can only be done for a limited number of samples. It is thus beneficial to maximize the information content of the samples analyzed via a targeted observation strategy. Using polychlorinated biphenyls (PCBs) as an example, a forecasting system to predict and evaluate long-range atmospheric transport (LRAT) episodes of POPs at a remote site in southern Norway has been developed. The system uses the Lagrangian particle transport model FLEXPART, and can be used for triggering extra ("targeted") sampling when LRAT episodes are predicted to occur. The system was evaluated by comparing targeted samples collected over 12-25 h during individual LRAT episodes with monitoring samples regularly collected over one day per week throughout a year. Measured concentrations in all targeted samples were above the 75th percentile of the concentrations obtained from the regular monitoring program and included the highest measured values of all samples. This clearly demonstrates the success of the targeted sampling strategy.

  17. Assessment of atmospheric distribution of polychlorinated biphenyls and polycyclic aromatic hydrocarbons using polyparameter model

    Directory of Open Access Journals (Sweden)

    Turk-Sekulić Maja M.

    2011-01-01

    Full Text Available Results of partial or total destruction of industrial plants, military targets, infrastructure, uncontrolled fires and explosions during the conflict period from 1991 to 1999, at the area of Western Balkans, were large amounts of hazardous organic matter that have been generated and emitted in the environment. In order to assess gas/particle partition of seven EPA polychlorinated biphenyls and sixteen EPA polycyclic aromatic hydrocarbons, twenty air samples have been collected at six urban, industrial and highly contaminated localities in Vojvodina. Hi-Vol methodology has been used for collecting ambiental air samples, that simultaneously collects gaseous and particulate phase with polyurethane foam filters (PUF and glass fiber filters (GFF. PUF and GFF filters have been analyzed, and concentration levels of gaseous PCBs and PAHs molecules in gaseous and particulate phase were obtained, converted and expressed through fraction of individual compounds sorbed onto particulate phase of the sample, in total detected quantity. Experimentally gained gas/particle partitioning values of PCBs and PAHs molecules have been compared with PP-LFER model estimated values. Significant deviation has been noticed during comparative analysis of estimated polyparameter model values for complete set of seven PCBs congeners. Much better agreement of experimental and estimated values is for polycyclic aromatic hydrocarbons, especially for molecules with four rings. These results are in a good correlation with literature data where polyparameter model has been used for predicting gas/particle partition of studied group of organic molecules.

  18. Characteristics of trophic transfer of polychlorinated biphenyls in marine organisms in Incheon North Harbor, Korea.

    Science.gov (United States)

    Kim, Seung Kyu; Lee, Dong Soo; Oh, Jae Ryong

    2002-04-01

    The trophic transfer of polychlorinated biphenyls (PCBs) was characterized for zooplankton (primarily Paracalanus spp. and Acartia spp.), pacific oyster (Crassostrea gigas), shore crab (Hemigrapsus penicillatus), and goby (Acanthogobius hasta) in the aquatic system of Incheon North Harbor, Korea. The congener pattern in the species was clearly divided by the main PCB uptake route. Compared with zooplankton and oyster, the fraction of heavier homologues increased in crab and goby that take PCBs from food. Linear relationships were observed between log (fugacity in lipid/fugacity in seawater) and log Kow for all the species. For zooplankton and oyster, such an observation should not be regarded as a true absence of superhydrophobicity, because establishment of equilibrium with seawater was not evident. For crab and goby, the absence of superhydrophobicity was evidenced by the trophic transfer factor that continuously increased with Kow up to 10(7.8). These results suggest that superhydrophobicity might be species specific. The trophic transfer factors and the fugacity levels in the lipid phase indicated that bioaccumulation in crab and goby advanced beyond the level in equilibrium with seawater in the harbor basin.

  19. Polychlorinated biphenyls in tree bark near a former manufacturing plant in Anniston, Alabama.

    Science.gov (United States)

    Hermanson, Mark H; Johnson, Glenn W

    2007-05-01

    Tree bark samples were collected to identify the relative amounts and congener profiles of atmospheric polychlorinated biphenyls dissolved into bark lipids from the gas phase in Anniston, Alabama, USA, where PCBs were manufactured from the 1920s until 1971. The area is heavily contaminated with PCBs: At least 4550 metric tons (mt) of PCB and 14000 mt of PCB distillation residue, known as Montar, remain buried in two landfills near the plant site. A minimum of 20.5 mt of PCBs were emitted to the atmosphere by the plant between 1953 and 1971 based on emissions figures for 1970. Bark results show that total PCB concentrations range over more than three orders of magnitude from 171927 ng/g lipid near the plant/landfill area, dropping exponentially to 35 ng/g lipid at a distance of about 7 km. The exponential trend is highly correlated (r=-0.77) and significant (ptree started growing after 1971 showing that atmospheric PCB concentrations remained high after PCB production ended. All PCB congener profiles show persistent congeners 31+28, 52, 66, 153, 138, and 180. Congener profiles from trees growing near the plant/landfill all have somewhat similar profiles but those growing during PCB production show high molecular mass compounds not usually found in the atmosphere and not found in younger trees, even in the most concentrated sample. We believe that high-temperature Montar disposal released high molecular mass PCBs into the gas phase which were dissolved into older tree bark lipids.

  20. An improved inventory of polychlorinated biphenyls in China: A case study on PCB-153

    Science.gov (United States)

    Xu, Yue; Tian, Chongguo; Wang, Xiaoping; Ma, Jianmin; Tang, Jianhui; Chen, Yingjun; Li, Jun; Zhang, Gan

    2018-06-01

    Emission inventory of pollutants is essential for the environmental fate study and management of the pollutant. To construct a reasonable PCB (polychlorinated biphenyls) inventory in China, this study estimates PCB usage and emission using power generating capacity, installed capacity of power plants and transformer substations, population density and GDP as surrogates. Inventory of representative PCB (PCB-153) with a resolution of 1/4° latitude × 1/4° longitude in China from 1952 to 2005 was generated and assessed as an example. Totally, about 20.3 kt PCBs were applied in China, of which 179 t were PCB-153. By the end of 2005, most of them (56.4%) were emitted into the soil, 2.7% entered the air, and about 20.8% was sealed in storage site or still in service. Historical emissions exhibited increasing trends after 1968, 1984 and 1994, which were mainly associated with usage or disposal processes. Although primary emission has been declined since 2005, the influence of secondary emission from soils, unintentionally produced PCBs (UP-PCB), and reemission from storage sites could be a long-lasting issue in the future. This new emission inventory improves previous PCB emission inventory significantly, which underestimated PCB emission in China considerably.

  1. Biofilms at work: Bio-, phyto- and rhizoremediation approaches for soils contaminated with polychlorinated biphenyls

    Directory of Open Access Journals (Sweden)

    Merily Horwat

    2015-09-01

    Full Text Available Organohalide contaminants such as polychlorinated biphenyls (PCBs have been released into the environment for decades due to anthropogenic activities, but are also naturally produced in small amounts through volcanic eruptions and geochemical processes. Although toxic to humans and other organisms, the natural production of these compounds has resulted in the evolution of naturally occurring organohalide-respiring bacteria that possess the enzymes necessary to degrade PCB compounds to non-toxic products. The efficiency of PCB degradation can be improved by facilitating the formation of organohalide-respiring biofilms. During biofilm colonization on a surface or interface, bacteria are encased in an extracellular polymeric substance (EPS or “slime,” which allows them to share nutrients and remain protected from environmental stresses. Effective bioremediation of PCBs involves facilitation of biofilm growth to promote cooperation between bacteria, which can be further enhanced by the presence of certain plant species. This review aims to give an overview of biofilm processes involved in the detoxification of PCBs including anaerobic and aerobic PCB degradation by bacteria as well as the ability of plants to stimulate microbial activity and degradation (rhizoremediation and phytoremediation.

  2. Polychlorinated biphenyl 126 stimulates basal and inducible aldosterone biosynthesis of human adrenocortical H295R cells

    International Nuclear Information System (INIS)

    Li, L.-A.; Wang, P.-W.; Chang, Louis W.

    2004-01-01

    To understand the effects of polychlorinated biphenyls (PCBs) on adrenal aldosterone biosynthesis, we have performed a systematical study to characterize the corresponding steroidogenic response of human adrenocortical cell line H295R to PCB126 exposure. We found that PCB126 at high concentrations stimulated basal and inducible aldosterone production. The aldosterone induction occurred concomitantly with activation of the CYP11B2 gene. Despite the fact that PCB126 acted in synergy with both potassium and angiotensin II (Ang II) in activation of aldosterone synthesis, PCB126 only modestly increased CYP11B2 mRNA expression in the presence of Ang II contrary to the synergistic transcriptional induction elicited by PCB126 and potassium. This implicated that PCB126 had differential interactions with the potassium and Ang II signaling systems in the regulation of aldosterone biosynthesis. In addition, high concentrations of PCB126 elevated transcriptional expression of the type I Ang II receptor (AT 1 ) and might thus sensitize the cellular Ang II responsiveness in both basal and inducible aldosterone biosynthesis. SF-1 was not involved in the PCB126-induced transcriptional regulation despite its importance in steroidogenic gene activation

  3. Enantioseparation and identification for the rationalization of the environmental impact of 4 polychlorinated biphenyls.

    Science.gov (United States)

    Guo, Fangjie; Tang, Qiaozhi; Xie, Jingqian; Zhao, Lu; Liu, Kai; Liu, Weiping

    2018-04-01

    Polychlorinated biphenyls (PCBs) are harmful and persistent organic pollutants that have long been used in industrial manufacturing. Their persistence leads to accumulation in the food chain causing potential toxic effects. As 19 out of 78 of the chiral congeners have stable atropisomers at ambient temperature, we studied some typical enantiomers: PCB45, PCB95, PCB136, and PCB149. The chiral stationary phases OD-H and OJ-H were used for separation in analytic high-performance liquid chromatography (HPLC), as well as for collection in semi-preparative HPLC. The resolution was optimized with respect to n-hexane-based mobile phases, temperature, and flow rate. All pure enantiomers were recovered from semi-preparative HPLC within 15 minutes for practical purpose. Characterization of the absolute configurations were conducted with a combination of theoretical and experimental electronic circular dichroism measurements. The enantiomers of PCB45, PCB95, PCB136, and PCB149 proved to be eluted as R > S, S > R, R > S, and S > R, respectively. Molecular structures (eg, substituent groups) and properties (eg, bond lengths, bond angles, and dipole moments) were quantitatively analyzed to understand the toxicity effect of PCBs. In summary, we have developed a well-established methodology of collection and configuration identification for analogous PCB derivatives. © 2018 Wiley Periodicals, Inc.

  4. Toxicological effects of polychlorinated biphenyls (PCBs) on freshwater turtles in the United States.

    Science.gov (United States)

    Ming-Ch'eng Adams, Clare Isabel; Baker, Joel E; Kjellerup, Birthe V

    2016-07-01

    Prediction of vertebrate health effects originating from persistent organic pollutants (POPs) such as polychlorinated biphenyls (PCBs) has remained a challenge for decades thus making the identification of bioindicators difficult. POPs are predominantly present in soil and sediment, where they adhere to particles due to their hydrophobic characteristics. Animals inhabiting soil and sediment can be exposed to PCBs via dermal exposure while others may obtain PCBs through contaminated trophic interaction. Freshwater turtles can serve as bioindicators due to their strong site fidelity, longevity and varied diet. Previous research observed the health effects of PCBs on turtles such as decreased bone mass, changed sexual development and decreased immune responses through studying both contaminated sites along with laboratory experimentation. Higher deformity rates in juveniles, increased mortality and slower growth have also been observed. Toxicological effects of PCBs vary between species of freshwater turtles and depend on the concertation and configuration of PCB congeners. Evaluation of ecotoxicological effects of PCBs in non-endangered turtles could provide important knowledge about the health effects of endangered turtle species thus inform the design of remediation strategies. In this review, the PCB presence in freshwater turtle habitats and the ecotoxicological effects were investigated with the aim of utilizing the health status to identify areas of focus for freshwater turtle conservation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Non-dioxin like polychlorinated biphenyl indicator congeners in Northwest Atlantic spiny dogfish (Squalus acanthias).

    Science.gov (United States)

    St-Gelais, Adam T; Aeppli, Christoph; Burnell, Craig A; Costa-Pierce, Barry A

    2017-07-15

    In the Northwest Atlantic Ocean (NWAO), spiny dogfish (Squalus acanthias) is a promising commercial species following of collapse of traditional groundfish stocks. There are little available data assessing polychlorinated biphenyls (PCBs) in NWAO spiny dogfish. Here, six non-dioxin like PCB indicator congeners used in European Union regulations (EU NDL-PCB) were quantified via gas chromatography/mass spectrometry in 50 mature male spiny dogfish landed in southern New England. The average total concentration of EU NDL-PCBs was 58±43ng/g (mean±1 standard deviation). PCB values (corrected for co-elution) were below the 200ng/g EU regulatory limit. Results provide first recent regional insight into the PCB content of spiny dogfish in the NWAO. However, our study offers only a snapshot of one particular dogfish population, and might not be representative for the whole NWAO. This study underscores the need for further testing in this species. Copyright © 2017. Published by Elsevier Ltd.

  6. Specific accumulation of polychlorinated biphenyls and organochlorine pesticides in Japanese common squid as a bioindicator

    International Nuclear Information System (INIS)

    Ueno, D.; Inoue, S.; Ikeda, K.; Tanaka, H.; Yamada, H.; Tanabe, S.

    2003-01-01

    Japanese common squid is a suitable bioindicator for monitoring organochlorines pollution in waters around Japan. - Organochlorines (OCs) representing Persistent Organic Pollutants (POPs) such as PCBs (polychlorinated biphenyls), DDTs (DDT and its metabolites), CHLs (chlordane compounds), HCHs (hexachlorocyclohexane isomers) and HCB (hexachlorobenzene) were determined in the liver of Japanese common squid (Todarodes pacificus) collected from the waters around Japan (Japan Sea and western North Pacific Ocean). Among OCs concentrations, PCBs (upto 5600 ng/g lipid wt.) were the highest, and those of other OCs were in the order of DDT> CHLs > HCHs > HCB. Studies on growth trend and seasonal variation of OCs in this species suggest a rapid reflection of the pollution levels in seawater where and when they were collected, regardless of body-length and time of collection. These results indicate that Japanese common squid is a suitable bioindicator for monitoring OCs pollution in waters around Japan. With regard to the geographical distribution of OCs in this species collected from waters around Japan, OCs concentrations in specimens from Japan Sea were higher than those from the Pacific Ocean. This result might reflect some existing of local pollution sources of OCs around Japan Sea, and slower water exchange between Japan Sea and open ocean

  7. Heavy metals and polychlorinated biphenyls (PCBs) sedimentation in the Lianhua Mountain Reservoir, Pearl River Delta, China.

    Science.gov (United States)

    Huang, Jingyu; Amuzu-Sefordzi, Basil; Li, Ming

    2015-05-01

    The Pearl River Delta is one of the biggest electronics manufacturing regions in the world. Due to the presence of abandoned industrial sites and the proliferation of large-scale electronics companies in the past four decades, it is therefore imperative to investigate the extent of heavy metals and polychlorinated biphenyls (PCBs) contamination in the region. Spatial and temporal distribution of heavy metals (Cr, Cu, Ni, Pb, and Zn) and PCBs (PCB28, PCB52, PCB101, PCB118, PCB138, PCB153, and PCB180) in the Lianhua Mountain reservoir in the Pearl River Delta, Dongguan City, China were examined based on a sedimentary profile analysis. Higher concentrations of the heavy metals detected were recorded in bottom sediments whereas 70% of the detected PCBs recorded maximum concentrations in top sediments. The geo-accumulation indices (Igeo) indicate that the study area is uncontaminated to moderately contaminated. Also, the integrated pollution indices (IPI) were above 1, except Pb, which shows that the study area is contaminated with heavy metals from anthropogenic sources. The concentrations of individual heavy metals and PCBs over a period of 60 years were also analyzed in order to establish a historical trend of pollution in the study area. This study provides baseline information on the level and historical trend of heavy metals and PCBs pollution in the study area.

  8. Polychlorinated biphenyls in freshwater salmonids from the Kerguelen Islands in the Southern Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Jaffal, A. [Laboratoire d' Eco-Toxicologie, EA 2069 Vignes et Vins de Champagne, Universite de Reims Champagne-Ardenne, F51687 Reims Cedex 2 (France); Givaudan, N. [UMR8079, CNRS, Orsay F-91405 (France); Univ Paris-Sud, Ecologie Systematique et Evolution, Orsay F-91405 (France); Betoulle, S. [Laboratoire d' Eco-Toxicologie, EA 2069 Vignes et Vins de Champagne, Universite de Reims Champagne-Ardenne, F51687 Reims Cedex 2 (France); Terreau, A. [IPEV Institut Polaire Francais, F29280 Plouzane (France); Paris-Palacios, S.; Biagianti-Risbourg, S. [Laboratoire d' Eco-Toxicologie, EA 2069 Vignes et Vins de Champagne, Universite de Reims Champagne-Ardenne, F51687 Reims Cedex 2 (France); Beall, E. [ECOBIOP, UMR 1224 INRA-Universite de Pau-Pays de l' Adour F63310 St-Pee-sur-Nivelle (France); Roche, H., E-mail: helene.roche@u-psud.fr [UMR8079, CNRS, Orsay F-91405 (France); Univ Paris-Sud, Ecologie Systematique et Evolution, Orsay F-91405 (France)

    2011-05-15

    The Subantarctic Kerguelen Islands (49{sup o}S, 70{sup o}E) contain freshwater ecosystems among the most isolated in the world. Concentrations of polychlorinated biphenyls (PCBs) were assessed in the muscle of 48 brook trout and 38 brown trout caught during summer and spring 2006 in the rivers, lakes and ponds of Kerguelen. The sum of 29 PCBs averaged 404 and 358 ng g{sup -1} lipid, and dioxin-like PCB was 19 and 69 ng g{sup -1} lipid, in brook and brown trout, respectively. The values showed a high variability and some fish accumulated PCBs at levels similar to those of fish from impacted areas. While inter-sex differences were limited, the season and the morphotype appeared to have the most influence. Fish captured in summer had muscle PCB concentrations about three times higher than those caught in spring and the 'river' morphotype of brook trout showed the highest PCB levels. - Highlights: > First assessment of PCB contamination of biota in Kerguelen Islands, Sub-Antarctica. > PCB bioaccumulation level in trout varies from very high to undetectable. > Habitat and morphotype are the most influential factors on the variability. > Distribution pattern of PCBs in the muscle of fish is morphotype dependent. - Salmonids in hydrosystems of the Kerguelen Islands (Southern Ocean) show a high PCB bioaccumulation.

  9. Polycyclic aromatic hydrocarbon metabolism in mullets, Chelon labrosus, treated by polychlorinated biphenyls

    International Nuclear Information System (INIS)

    Narbonne, J.F.; Suteau, P.; Daubeze, M.; Audy, C.

    1987-01-01

    Contamination of the ocean by hydrocarbons has become a major environmental problem. Consequently, it is not surprising that residues of potentially toxic xenobiotics, such as benzo(a)pyrene (B(a)P), are present in marine species used as human food. The oxidative metabolism of aromatic hydrocarbons proceeds via intermediate arene oxides. Some of these metabolites are very reactive electrophiles and may interact with cellular macromolecules such as proteins, DNA and RNA. Thus, the ability of an organism to further metabolize arene oxides can be an important protective mechanism against the possible toxic effect of these molecules. The existence of hepatic cytochrome P-450 dependent monooxygenase activities in fish is now well established. The exposure of fish to polychlorinated biphenyls (PCB) increases both the monooxygenase activities and the total amount of cytochrome P-450 in the microsomal fractions of fish liver. The purpose of this study was to compare the toxication-detoxication balance in both control and PCB induced estuarine fish (Grey mullets)

  10. Sex difference in polychlorinated biphenyl concentrations of burbot Lota lota from Lake Erie

    Science.gov (United States)

    Madenjian, C.P.; Stapanian, M.A.; Rediske, R.R.; O’Keefe, J. P.

    2013-01-01

    Whole-fish polychlorinated biphenyl (PCB) concentrations were determined for 25 female and 25 male burbot Lota lota from Lake Erie. Bioenergetics modeling was used to investigate whether the sex difference in growth rate resulted in a difference in gross growth efficiency (GGE) between the sexes. For ages 6–13 years, male burbot averaged 28 % greater PCB concentrations than female burbot. The sex difference in PCB concentrations widened for ages 14–17 years, with male burbot having, on average, 71 % greater PCB concentrations than female burbot. Bioenergetics modeling results showed that the faster growth rate exhibited by female burbot did not lead to greater GGE in female individuals of the younger burbot and that the faster growth by female fish led to female GGE being only 2 % greater than male GGE in older burbot. Although our bioenergetics modeling could not explain the observed sex difference in PCB concentrations, we concluded that a sex difference in GGE was the most plausible explanation for the sex difference in PCB concentrations of burbot ages 6–13 years. Not only are male fish likely to be more active than female fish, but the resting metabolic rate of male fish may be greater than that of female fish. We also concluded that the widening of the sex difference in PCB concentrations for the older burbot may be due to many of the older male burbot spending a substantial amount of time in the vicinity of mouths of rivers contaminated with PCBs.

  11. Oxidation of dibenzothiophene (DBT by Serratia marcescens UCP 1549 formed biphenyl as final product

    Directory of Open Access Journals (Sweden)

    de Araújo Hélvia W

    2012-05-01

    Full Text Available Abstract Background The desulphurization of dibenzothiophene (DBT, a recalcitrant thiophenic fossil fuel component by Serratia marcescens (UCP 1549 in order for reducing the Sulphur content was investigated. The Study was carried out establishing the growth profile using Luria Bertani medium to different concentrations of DBT during 120 hours at 28°C, and orbital Shaker at 150 rpm. Results The results indicated that concentrations of DBT 0.5, 1.0 and 2.0 mM do not affected the growth of the bacterium. The DBT showed similar Minimum Inhibitory Concentration (MIC and Minimum Bactericidal Concentration (MCB (3.68 mM. The desulphurization of DBT by S. marcescens was used with 96 hours of growth on 2 mM of DBT, and was determined by gas chromatography (GC and GC-mass spectrometry. In order to study the desulphurization process by S. marcescens was observed the presence of a sulfur-free product at 16 hours of cultivation. Conclusions The data suggests the use of metabolic pathway “4S” by S. marcescens (UCP 1549 and formed biphenyl. The microbial desulphurization process by Serratia can be suggest significant reducing sulphur content in DBT, and showed promising potential for reduction of the sulfur content in diesel oil.

  12. Distribution of polychlorinated biphenyls in the Housatonic River and adjacent aquifer, Massachusetts

    Science.gov (United States)

    Gay, Frederick B.; Frimpter, Michael H.

    1985-01-01

    Polychlorinated biphenyls (PCB's) are sorbed to the fine-grained stream-bottom sediments along the Housatonic River from Pittsfield, Massachusetts, southward to the Massachusetts-Connecticut boundary. The highest PCB concentrations, up to 140,000 micrograms per kilogram, were found in samples of bottom material from a reach of the river between Pittsfield and Woods Pond Dam in Lee, Massachusetts. Sediments in Woods Pond have been estimated to contain about 11,000 pounds of PCB's. Approximately 490 pounds per year of PCB's have also been estimated to move past the Housatonic River gaging station at Great Barrington. The distribution of hydraulic heads, water temperatures, and concentrations of dissolved oxygen, ammonia, nitrate, iron, and manganese in ground water shows that industrial water-supply wells in a sand and gravel aquifer adjacent to a stretch of the river called Woods Pond have been inducing ground-water recharge through the PCB-contaminated bottom sediments of the pond since late 1956. These data indicate that, at one location along the shore of the pond, the upper 40 feet of the aquifer contains water derived from induced infiltration. However, this induced recharge has not moved PCB's from the bottom sediments into a vertical section of the aquifer located 5 feet downgradient from the edge of Woods Pond. Samples taken at selected intervals in this section showed that no PCB's sorbed to the aquifer material or dissolved in the ground water within the detection limits of the chemical analyses.

  13. Importance of growth rate on mercury and polychlorinated biphenyl bioaccumulation in fish

    Science.gov (United States)

    Li, Jiajia; Haffner, G. Douglas; Patterson, Gordon; Walters, David M.; Burtnyk, Michael D.; Drouillard, Ken G.

    2018-01-01

    To evaluate the effect of fish growth on mercury (Hg) and polychlorinated biphenyl (PCB) bioaccumulation, a non–steady‐state toxicokinetic model, combined with a Wisconsin bioenergetics model, was developed to simulate Hg and PCB bioaccumulation in bluegill (Lepomis macrochirus). The model was validated by comparing observed with predicted Hg and PCB 180 concentrations across 5 age classes from 5 different waterbodies across North America. The non–steady‐state model generated accurate predictions for Hg and PCB bioaccumulation in 3 of 5 waterbodies: Apsey Lake (ON, Canada), Sharbot Lake (ON, Canada), and Stonelick Lake (OH, USA). The poor performance of the model for the Detroit River (MI, USA/ON, Canada) and Lake Hartwell (GA/SC, USA), which are 2 well‐known contaminated sites with possibly high heterogeneity in spatial contamination, was attributed to changes in feeding behavior and/or prey contamination. Model simulations indicate that growth dilution is a major component of contaminant bioaccumulation patterns in fish, especially during early life stages, and was predicted to be more important for hydrophobic PCBs than for Hg. Simulations that considered tissue‐specific growth provided some improvement in model performance particularly for PCBs in fish populations that exhibited changes in their whole‐body lipid content with age. Higher variation in lipid growth compared with that of lean dry protein was also observed between different bluegill populations, which partially explains the greater variation in PCB bioaccumulation slopes compared with Hg across sampling sites.

  14. Atmospheric occurrence, transport and gas-particle partitioning of polychlorinated biphenyls over the northwestern Pacific Ocean

    Science.gov (United States)

    Wu, Zilan; Lin, Tian; Li, Zhongxia; Li, Yuanyuan; Guo, Tianfeng; Guo, Zhigang

    2017-10-01

    Ship-board air samples were collected during March to May 2015 from the East China Sea (ECS) to the northwestern Pacific Ocean (NWP) to explore the atmospheric occurrence and gas-particle partitioning of polychlorinated biphenyls (PCBs) when the westerly East Asian Monsoon prevailed. Total PCB concentrations in the atmosphere ranged from 56.8 to 261 pg m-3. Higher PCB levels were observed off the coast and minor temperature-induced changes showed that continuous emissions from East Asia remain as an important source to the regional atmosphere. A significant relationship between Koa (octanol-air partition coefficient) and KP (gas-particle partition coefficient) for PCBs was observed under continental air masses, suggesting that land-derived organic aerosols affected the PCB gas-particle partitioning after long-range transport, while an absence of this correlation was identified in marine air masses. The PCB partitioning cannot be fully explained by the absorptive mechanism as the predicted KP were found to be 2-3 orders of magnitude lower than the measured Kp, while the prediction was closely matched when soot adsorption was considered. The results suggested the importance of soot carbon as a transport medium for PCBs during their long-range transport and considerable impacts of continental outflows on PCBs across the downwind area. The estimated transport mass of particulate PCBs into the ECS and NWP totals 2333 kg during the spring, constituting ca. 17% of annual emission inventories of unintentionally produced PCB in China.

  15. Dioxin-like polychlorinated biphenyls in marine fish from Shandong, China, and human dietary exposure.

    Science.gov (United States)

    Cao, Yanping; Jiang, Dafeng; Li, Fenghua; Chen, Jindong; Li, Wei; Jiao, Yanni; Li, Lu

    2018-05-22

    The occurrence and human dietary exposure of 12 dioxin-like polychlorinated biphenyls (DL-PCBs) in 41 marine fish samples from Shandong Province of China were investigated. The DL-PCB congeners were extracted using automated Soxhlet extraction, purified via a composite column cleanup procedure and analyzed by gas chromatography-triple quadrupole mass spectrometry. DL-PCB congeners were found in all analyzed samples, with a mean concentration of 0.887 ng/g ww (wet weight). The TEQ concentrations of DL-PCBs in individual fish samples ranged from 0.011 to 9.214 pg WHO TEQ/g ww. The mean dietary intake for all fish species was 36.5 pg TEQ/kg bw/month, which was lower than the provisional tolerable monthly intake of 70 pg TEQ/kg bw/month set by the Joint FAO/WHO Expert Committee on Food Additives. To monitor the trend of DL-PCBs in fish for food safety control it is necessary to maintain a surveillance program.

  16. A review of the neurotoxicity of non-dioxin-like polychlorinated biphenyls

    Energy Technology Data Exchange (ETDEWEB)

    Seegal, R. [Albany Univ., NY (United States). Wadsworth Center, New York State Dept. of Health and School of Public Health

    2004-09-15

    It is perhaps both presumptuous and somewhat nostalgic for me to present research findings from both myself and others describing the changes in central nervous system (CNS) function that occur following exposure to non-dioxin-like polychlorinated biphenyls (PCBs) at the 2004 Dioxin meeting. Presumptuous because my presentation occurs during this meeting where the majority of the research is concerned with the consequences of exposure to dioxins (the most toxic substance produced by man) and nostalgic because, in 1992, I presented some of my earliest work demonstrating that non-dioxin-like PCBs were capable of significantly altering neurochemical function. Much has changed in the intervening twelve years. Laboratories in the United States and Europe now routinely study and describe the neurotoxicological effects of developmental and in vitro exposure to non-dioxin-like PCBs. My task will be to briefly describe the highlights of that research and suggest additional approaches that will hopefully increase our ability to understand the mechanisms of action of non-dioxin-like PCBs on neuronal and behavioral function in populations of exposed humans.

  17. Organochlorine pesticides and polychlorinated biphenyls in herring from the southern Baltic, 1983

    Energy Technology Data Exchange (ETDEWEB)

    Falandysz, J

    1986-02-01

    Hexachlorobenzene (HCB), alpha-, beta-, gamma- and delta-benzenehexachloride (BHC, HCH), p,p'-DDE, o,p'-DDD, o,p'-DDT, p,p'-DDD and p,p'-DDT (sigma DDT) and polychlorinated biphenyls (PCB) levels have been determined in muscle tissue of 187 herring (Clupea harengus) netted during 1983 in a different regions in the southern part of the Baltic Sea. The mean levels found for herring muscle tissue related to wet weight (microgram/kg) were: 14 HCB, 18 alpha-BHC, 23 beta-BHC, 14 gamma-BHC, delta-BHC remained undetected, 56 sigma BHC, 115 p,p'-DDE, o,p'-DDD and o,p'-DDT remained undetected, 84 p,p'-DDD, 51 p,p'-DDT, 250 sigma DDT and 530 PCB. The levels of organochlorine pesticides determined in wet muscles or extractable lipids of herring are nearly 2-3 times as high as those noted in fish sampled in the same area in two years before, while for PCBs the wet weight levels were comparable, and when based on a lipid weight are somewhat higher. The results are compared with levels found in herring collected in different regions of the Baltic Sea during 1965-1983, and reported previously by other authors.

  18. Passive air sampling of polychlorinated biphenyls, organochlorine compounds, and polybrominated diphenyl ethers across Asia.

    Science.gov (United States)

    Jaward, Foday M; Zhang, Gan; Nam, Jae Jak; Sweetman, Andrew J; Obbard, Jeffrey P; Kobara, Yuso; Jones, Kevin C

    2005-11-15

    Asia is of global importance economically, yet data on ambient persistent organic pollutant levels are still sparse for the region, despite international efforts under the Stockholm Convention to identify and reduce emissions. A large-scale passive air sampling survey was therefore conducted in Asia, specifically in China, Japan, South Korea, and Singapore. Polyurethane foam disks were deployed simultaneously at 77 sites, between Sept 21 and Nov 16, 2004, and analyzed for polychlorinated biphenyls (PCBs), organochlorine compounds (hexachlorobenzene (HCB), dichlorodiphenyltrichloroethanes (DDTs), chlordane), and polybrominated diphenyl ethers (PBDEs). The meteorological conditions prevailing in the region at this time facilitated the assessment of local/regional differences in atmospheric emissions, because large-scale advection effects due to monsoons or dust storms did not occur. Air concentrations estimated assuming an average sampler uptake rate of 3.5 m3/day ranged as follows (pg m(-3)): PCBs, 5-340; HCB, 10-460; DDTs, 0.4-1800; chlordanes, 1-660; PBDEs, < 0.13-340. South Korea and Singapore generally had regionally low concentrations. Elevated concentrations of PCBs, DDTs, and HCB occurred at sites in China, higher than reported in a similar recent sampling campaign in Europe. Chlordane was highest in samples from Japan (which also had elevated levels of PCBs and DDTs) and was also elevated in some Chinese locations. PBDE levels were generally low in the region.

  19. Indicator polychlorinated biphenyl residues in muscle tissue of fish from Black Sea coast of Bulgaria

    Directory of Open Access Journals (Sweden)

    S. Georgieva

    2016-06-01

    Full Text Available Abstract. Polychlorinated biphenyls (PCBs are characterized by high lipophilicity and persistence in the environment and will therefore bioaccumulate and biomagnify in the food chain. PCBs were determined in muscle tissue of four fish species: goby (Neogobius melanostomus, horse mackerel (Trachurus Mediterraneus ponticus, shad (Alosa pontica pontica and turbot (Psetta maxima maeotica. Samples were collected from Bulgarian Black Sea coast during 2007 – 2011. The PCBs were analyzed in order to examine the time trends of PCB concentrations in fish from Black Sea. The six individual PCBs congeners were determined by capillary gas chromatography system with mass spectrometry detection. PCBs were found in all fish species at concentrations ranging between 2.32 ng/g ww (wet weight and 32.87 ng/g ww in goby and shad, respectively. PCB profiles have been found to be similar in all the fish species tested. The most abundant PCB congeners in fish species were hexa- and heptachlorinated PCBs 138, 153 and 180. PCB 153 was the dominant congener in all fish studied and were found in the range from 0.95 ng/g ww (horse mackerel 2011 to 11.67 ng/g ww (shad 2010. The sum of six indicator PCBs in all fish species did not exceed the European maximum limit of 75 ng/g ww. The levels of PCBs in fish from Bulgarian Black Sea coast were found lower than in fish species from other seas – the Aegean Sea and the Mediterranean Sea.

  20. Occupational exposure to polychlorinated biphenyls and risk of cutaneous melanoma: a meta-analysis.

    Science.gov (United States)

    Boffetta, Paolo; Catalani, Simona; Tomasi, Cesare; Pira, Enrico; Apostoli, Pietro

    2018-01-01

    The aim of this study was to carry out a meta-analysis of studies on exposure to polychlorinated biphenyls (PCBs) and the risk of malignant melanoma (MM). We searched Scopus, PubMed, and reference lists; among 807 potentially relevant articles, we selected those based on 12 populations. Data were extracted according to a standardized form; the Newcastle-Ottawa Scale was used to assess study quality. Meta-analyses were carried out according to fixed-effect and random-effects models. The fixed-effect summary relative risk (RR) for MM was 0.91 [95% confidence interval (CI): 0.82-1.00]; the random-effects summary RR was 1.05 (95% CI: 0.78-1.32). The random-effects summary RR from eight occupational cohorts was 1.13 (95% CI: 0.91-1.35) and that from four community-based studies was 0.84 (95% CI: 0.36-1.31). The quality of the studies and the methods for PCB exposure assessment did not influence the RR. These results do not support the hypothesis of an association between PCB exposure and the risk of MM.

  1. Contamination by polychlorinated biphenyls (PCBs) in striped dolphins (Stenella coeruleoalba) from the Southeastern Mediterranean Sea.

    Science.gov (United States)

    Storelli, Maria Maddalena; Barone, Grazia; Giacominelli-Stuffler, Roberto; Marcotrigiano, Giuseppe Onofrio

    2012-09-01

    Concentrations of polychlorinated biphenyls (PCBs) including dioxin-like PCBs (non-ortho, PCB 77, PCB 126, and PCB 169 and mono-ortho, PCB 105, PCB 118, and PCB 156) were measured in different organs and tissues (melon, blubber, liver, kidney, lung, heart, and muscle tissue) of striped dolphins (Stenella coeruleoalba) from the Eastern Mediterranean Sea (Adriatic Sea). The mean highest levels were in blubber and melon, followed by liver, kidney, lung, heart, and muscle tissue. PCB profiles were similar in all tissues and organs being dominated by the higher chlorinated homologues (hexa-CBs, 55.8-62.1%; penta-CBs, 15.4-20.0%; and hepta-CB PCB 180, 12.7-16.5%). Major PCBs in all tissues were congeners 138 and 153 collectively accounting for 50.6-58.3% of the total PCB concentrations, followed by PCB 101, 105, 118, and 180 constituting from 27.0% to 31.0%. PCB levels were higher in adult males than in adult females. The estimated 2,3,7,8-TCDD toxic equivalents of non- and mono-ortho PCBs were much higher than the threshold level above which adverse effects have been observed in other marine mammals species, suggesting that striped dolphins in this region are at risk for toxic effects.

  2. Effect of polychlorinated biphenyls on osmoregulatory response and apoptosis in GIFT tilapia, Oreochromis niloticus.

    Science.gov (United States)

    Zheng, Y; Qiu, L; Fan, L; Song, C; Meng, S; Chen, J

    2016-09-02

    In the present study, GIFT tilapia Oreochromis niloticus were exposed to polychlorinated biphenyls (PCBs) for 7, 14, and 21 days. Over the duration of the exposure, genotoxicity and the activity of Na + /K + -ATPase (NKA) and Ca + /Mg + -ATPase (CMA) were measured in the gill, kidney, and intestine, to evaluate changes in osmoregulatory response in O. niloticus. Our results showed significant decreases in organic NKA (except in gill tissues after 0.5 mg/L PCB-exposure) and CMA activity. The results of the genotoxicity assay showed significant increases in atp1a1a, nkcc2 (only in gill tissue), and fxyd7 (except after 21 days of 5 mg/L PCB exposure). We found significant increases in caspase proteins in the liver in the 5-mg/L PCB exposure group, and the transcripts showed dose-dependent increases between treatment groups over the exposure duration. This study presents evidence that chronic exposure to PCB could result in organic osmoregulatory response and hepatic apoptosis in GIFT tilapia.

  3. Concentrations and Toxic Equivalency of Polychlorinated Biphenyls in Polish Wastewater Treatment Plant Effluents.

    Science.gov (United States)

    Urbaniak, Magdalena; Kiedrzyńska, Edyta

    2015-10-01

    Wastewater treatment plants (WWTPs) are widely recognized as important sources of toxic contaminants such as polychlorinated biphenyls (PCBs). An example is given in the present paper, where concentrations of 12 dioxin-like PCBs (dl-PCBs) congeners were investigated in effluents from 14 WWTPs of different sizes, using gas chromatography tandem-mass spectrometry. The results obtained demonstrate that the smallest WWTPs are characterized by the highest total dl-PCB concentration of 102.69 pg/L, roughly twice those of medium-size and large WWTPs, i.e. 41.14 and 48.29 pg/L, respectively. In all cases, the concentrations obtained were generated mostly by increased contributions of PCB-77, PCB-105 and PCB-118 which constituted 48 %-59 % of the mean dl-PCB concentration. The results also reveal a predominance of mono-ortho over non-ortho PCBs. All three types of WWTP effluent were found to have similar toxic equivalency (TEQ) values, ranging from 0.31 for large to 0.37 pg TEQ/L for medium WWTPs.

  4. Polychlorinated biphenyls and polybrominated diphenyl ethers in the North American atmosphere

    International Nuclear Information System (INIS)

    Shen Li; Wania, Frank; Lei, Ying D.; Teixeira, Camilla; Muir, Derek C.G.; Xiao, Hang

    2006-01-01

    To assess the spatial concentration variability of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in the atmosphere on a large continental scale, their annually integrated air concentrations were determined in 2000/2001 using XAD-based passive air samplers (PAS). The network included 40 stations in Canada, the United States, Mexico, Belize and Costa Rica, and covered 72 degrees of latitude and longitude. Total concentrations of PCB and PBDE congeners ranged from below the detection limit to 130 ng PAS -1 and 24 ng PAS -1 , respectively. PCBs displayed a large variation between urban, rural and remote sites, whereas PBDEs did not follow such a pattern. Open burning of 'Penta'-containing waste may have contributed to the PBDEs detected in the air samples from rural and remote areas. Air from the Canadian Arctic had a relatively higher percentage of lighter PCB congeners than air sampled in the tropical region, which is interpreted as evidence for global fractionation. - A continental passive air sampling network reveals atmospheric distribution patterns of two classes of industrial chemicals

  5. Placental markers of human exposure to polychlorinated biphenyls and polychlorinated dibenzofurans

    International Nuclear Information System (INIS)

    Lucier, G.W.; Nelson, K.G.; Everson, R.B.; Wong, T.K.; Philpot, R.M.; Tiernan, T.; Taylor, M.; Sunahara, G.I.

    1987-01-01

    These studies have evaluated biochemical changes in placentae from humans exposed to rice oil contaminated with polychlorinated biphenyls (PCBs) and polychlorinated dibenzofurans (PCDFs) in Taiwan. Placentae were obtained from nonsmoking women 4 to 5 years after the exposure had occurred. The exposed individuals ingested approximately 1 to 3 g PCBs and 5 mg PCDFs, and many exhibited symptoms characteristic of PCB poisoning. This disease was termed Yu-Cheng in Chinese. Based on data from experimental animals models, the authors examined a number of parameters in placentae from control and exposed women, including arylhydrocarbon hydroxylase (AHH) activity, cytochrome P-450 isozymes, epidermal growth factor (EGF) receptor binding properties and actions, and Ah receptor. They also quantified concentrations of various PCB and PCDF congeners known to be present in the contaminated rice oil. The results revealed a dramatic elevation in placental AHH activity in samples from PCB/PCDF-exposed women. This increase in enzyme activity was associated with a parallel increase in placental microsomal protein immunochemically related to cytochrome P-450 form 6. EGF receptor-mediated autophosphorylation capacity was significantly diminished in PCB/PCDF placentae, but this effect was not associated with changes in plasma membrane EGF receptor binding properties. Two PCDF congeners were detected in Yu-Cheng placentae but not controls. Several PCBs were also detected in much higher concentrations in Yu-Cheng placentae. Surprisingly, placental concentrations of PCBs correlated better with effects than did the PCDFs. The findings are discussed in relation to the risk assessment process

  6. Importance of passive diffusion in the uptake of polychlorinated biphenyls by phagotrophic protozoa

    Energy Technology Data Exchange (ETDEWEB)

    Kujawinski, E.B.; Farrington, J.W.; Moffett, J.W.

    2000-05-01

    Unicellular protozoan grazers represent a size class of organisms where a transition in the mechanism of chlorobiphenyl (CB) introduction, from diffusion through surface membranes to ingestion of contaminated prey, could occur. This study compares the relative importance of these two processes in the overall uptake of polychlorinated biphenyls by protists. Uptake rates and steady-state concentrations were compared in laboratory cultures of grazing and nongrazing protozoa. These experiments were conducted with a 10-{micro}m marine scuticociliate (Uronema sp.), bacterial prey (Halomonas halodurans), and a suite of 21 CB congeners spanning a range of aqueous solubilities. The dominant pathway of CB uptake by both grazing and nongrazing protozoa was diffusion. Organic-carbon-normalized CB concentrations (in the protozoan cell) were equivalent in grazing and nongrazing protozoa for all congeners studied. Rate constants for uptake into and loss from the protozoan cell were independently determined by using [3,3{prime}, 4,4{prime}-{sup 14}C]tetrachlorobiphenyl (IUPAC no. 77), 0.38 {+-} 0.03 min{sup {minus}1} and (1.1 {+-} 0.1) x 10{sup {minus}5} (g of organic carbon){minus}{sup {minus}1} min{sup {minus}1}, respectively. Magnitudes of the uptake and loss processes were calculated and compared by using a numerical model. The model result was consistent with data from the bioaccumulation experiment and supported the hypothesis that diffusive uptake is faster than ingestive uptake in phagotrophic unicellular protozoa.

  7. Age-related polychlorinated biphenyl dynamics in immature bull sharks (Carcharhinus leucas).

    Science.gov (United States)

    Olin, Jill A; Beaudry, Marina; Fisk, Aaron T; Paterson, Gordon

    2014-01-01

    Polychlorinated biphenyls (PCBs) were quantified in liver tissues of bull sharks (Carcharhinus leucas) ranging in age from 3 yr. Summed values of PCBs (ΣPCBs) ranged from 310 ng/g to 22 070 ng/g (lipid wt) across age classes with ΣPCB concentrations for the youngest sharks in the present study (3-yr-old sharks, highlighting the extent of exposure of this young life stage to this class of persistent organic pollutants (POPs). Age normalization of PCB congener concentrations to those measured for the youngest sharks demonstrated a significant hydrophobicity (log octanol/water partition coefficient [KOW ]) effect that was indicative of maternal offloading of highly hydrophobic (log KOW ≥6.5) congeners to the youngest individuals. A distinct shift in the PCB congener profiles was also observed as these young sharks grew in size. This shift was consistent with a transition from the maternally offloaded signal to the initiation of exogenous feeding and the contributions of mechanisms including growth dilution and whole-body elimination. These results add to the growing pool of literature documenting substantially high concentrations of POPs in juvenile sharks that are most likely attributable to maternal offloading. Collectively, such results underscore the potential vulnerability of young sharks to POP exposure and pose additional concerns for shark-conservation efforts. © 2013 SETAC.

  8. Presence of polychlorinated biphenyls (PCBs) in bottled drinking water in Mexico City.

    Science.gov (United States)

    Salinas, Rutilio Ortiz; Bermudez, Beatriz Schettino; Tolentino, Rey Gutiérrez; Gonzalez, Gilberto Díaz; Vega y León, Salvador

    2010-10-01

    This paper describes the concentrations of seven polychlorinated biphenyls (PCBs) in bottled drinking water samples that were collected over 1 year from Mexico City in two sizes (1.5 and 19 L), using gas chromatography with an electron capture detector. PCBs 28 (0.018-0.042 μg/L), 52 (0.006-0.015 μg/L) and 101 (0.001-0.039 μg/L) were the most commonly found and were present in the majority of the samples. However, total concentrations of PCBs in bottled drinking water (0.035-0.039 μg/L) were below the maximum permissible level of 0.50 μg/L stated in Mexican regulations and probably do not represent a hazard to human health. PCBs were detectable in all samples and we recommend a monitoring program be established to better understand the quality of drinking bottled water over time; this may help in producing solutions for reducing the presence of organic contaminants.

  9. Detailed analysis of polybrominated biphenyl congeners in bird eggs from Norway

    International Nuclear Information System (INIS)

    Vetter, Walter; Recke, Roland von der; Herzke, Dorte; Nygard, Torgeir

    2008-01-01

    Individual eggs of six species of birds from Norway representing different food chains were analysed for residues of polybrominated biphenyls (PBBs). In all species, the residue pattern was dominated by hexaBBs. The dominating congeners were PBB 153, PBB 154, and PBB 155. Whereas PBB 153 is present in technical hexabromobiphenyl, PBB 154 and PBB 155 are formed by the reductive debromination of decabromobiphenyl. This was evidenced by the detection of several heptaBBs and octaBBs all of which are typical degradation intermediates of PBB 209. Hepta- and octaBBs were more than one order of magnitude less abundant than the hexaBBs. The second most prevailing homologue group was pentaBBs. The most relevant pentabrominated isomers were PBB 99 and PBB 101. Concentrations of the three hexaBBs - PBB 153, PBB 154, and PBB 155 - amounted to 1.3-13 ng/g wet weight or 3-23% of the contamination with polybrominated diphenyl ethers. - We provide for the first time detailed information on the PBB congeners present in eggs of bird of prey, and quantified three hexabromo congeners

  10. Uptake of polychlorinated biphenyls and organochlorine pesticides from soil and air into radishes (Raphanus sativus)

    Energy Technology Data Exchange (ETDEWEB)

    Mikes, Ondrej; Cupr, Pavel [RECETOX, Research Centre for Environmental Chemistry and Ecotoxicology, Masaryk University, Kamenice 126/3, 625 00 Brno (Czech Republic); Trapp, Stefan [Department of Environmental Engineering, Technical University of Denmark, Miljoevej 113, DK-2800 Kgs. Lyngby (Denmark); Klanova, Jana [RECETOX, Research Centre for Environmental Chemistry and Ecotoxicology, Masaryk University, Kamenice 126/3, 625 00 Brno (Czech Republic)], E-mail: klanova@recetox.muni.cz

    2009-02-15

    Uptake of organochlorine pesticides and polychlorinated biphenyls from soil and air into radishes was measured at a heavily contaminated field site. The highest contaminant concentrations were found for DDT and its metabolites, and for {beta}-hexachlorocyclohexane. Bioconcentration factor (BCF, defined as a ratio between the contaminant concentration in the plant tissue and concentration in soil) was determined for roots, edible bulbs and shoots. Root BCF values were constant and not correlated to log K{sub OW}. A negative correlation between BCF and log K{sub OW} was found for edible bulbs. Shoot BCF values were rather constant and varied between 0.01 and 0.22. Resuspended soil particles may facilitate the transport of chemicals from soil to shoots. Elevated POP concentrations found in shoots of radishes grown in the control plot support the hypothesis that the uptake from air was more significant for shoots than the one from soil. The uptake of POPs from air was within the range of theoretical values predicted from log K{sub OA}. - Uptake from air represented for majority of persistent organochlorines a dominant pathway into shoots while uptake from soil was dominant for roots.

  11. Dietary taurine alters ascorbic acid metabolism in rats fed diets containing polychlorinated biphenyls.

    Science.gov (United States)

    Mochizuki, H; Oda, H; Yokogoshi, H

    2000-04-01

    The effect of dietary taurine on ascorbic acid metabolism and hepatic drug-metabolizing enzymes was investigated in rats fed diets containing polychlorinated biphenyls (PCB) to determine whether taurine has an adaptive and protective function in xenobiotic-treated animals. Young male Wistar rats (60 g) were fed diets containing 0 or 0.2 g/kg diet PCB with or without 30 g/kg diet of taurine for 14 d. The rats fed the PCB-containing diets had greater liver weight, higher ascorbic acid concentrations in the liver and spleen and greater hepatic cytochrome P-450 contents than control rats that were not treated with PCB (P ascorbic acid excretion was enhanced, and serum cholesterol concentration (especially HDL-cholesterol) was significantly elevated compared with those in control rats. Dietary taurine significantly potentiated the increases in the urinary excretion of ascorbic acid and the rise in the levels of cytochrome P-450 which were caused by PCB treatment. On the other hand, the supplementation of taurine to control diet did not alter these variables. Taurine may enhance the hepatic drug-metabolizing systems, leading to the stimulation of the ascorbic acid metabolism in rats fed diets containing PCB.

  12. Polychlorinated biphenyls in alfalfa: Accumulation, sorption and speciation in different plant parts.

    Science.gov (United States)

    Teng, Ying; Sun, Xianghui; Zhu, Lingjia; Christie, Peter; Luo, Yongming

    2017-08-03

    The accumulation, chemical speciation and distribution of polychlorinated biphenyls (PCBs) were investigated in various parts of alfalfa. Moreover, the adsorption characteristics for PCB 28 by alfalfa and the influencing factors of the adsorption characteristics were studied. There were different degrees of PCB accumulation in alfalfa roots, root nodules and shoots. The decreasing order of the accumulation of PCBs in plant tissues was root nodules > roots > shoots, and the decreasing order of the total PCB contents was roots > shoots > root nodules, indicating that the roots were the main sink for PCB accumulation. There were three modes of PCB speciation in alfalfa roots and root nodules, comprising strong sorption (78%) and weak sorption (19%) on tissue surfaces and absorption within tissues (2%). The adsorption isotherms of PCB 28 indicate that the adsorption capacities of root nodules and shoots were both significantly higher than that of the roots. Both lipids and carbohydrates, and especially lipids, affected the PCB adsorption capacities of the tissues. These results may help in the elucidation of the mechanisms of sorption and accumulation of PCBs in the plants and their main influencing factors and thus contribute to the development of phytoremediation technologies for PCB-contaminated soils.

  13. Structural insights into the metabolism of 2-chlorodibenzofuran by an evolved biphenyl dioxygenase

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Pravindra; Mohammadi, Mahmood; Dhindwal, Sonali; Pham, Thi Thanh My; Bolin, Jeffrey T.; Sylvestre, Michel (INRS); (IIT-India); (Purdue)

    2012-06-28

    The biphenyl dioxygenase of Burkholderia xenovorans LB400 (BphAE{sub LB400}) is a Rieske-type oxygenase that catalyzes the stereospecific oxygenation of many heterocyclic aromatics including dibenzofuran. In a previous work, we evolved BphAE{sub LB400} and obtained BphAE{sub RR41}. This variant metabolizes dibenzofuran and 2-chlorodibenzofuran more efficiently than BphAE{sub LB400}. However, the regiospecificity of BphAE{sub RR41} toward these substrates differs. Dibenzofuran is metabolized principally through a lateral dioxygenation whereas 2-chlorodibenzofuran is metabolized principally through an angular dioxygenation. In order to explain this difference, we examined the crystal structures of both substrate-bound forms of BphAE{sub RR41} obtained under anaerobic conditions. This structure analysis, in combination with biochemical data for a Ser283Gly mutant provided evidences that the substrate is compelled to move after oxygen-binding in BphAE{sub RR41}:dibenzofuran. In BphAE{sub RR41}:2-chlorodibenzofuran, the chlorine atom is close to the side chain of Ser283. This contact is missing in the BphAE{sub RR41}:dibenzofuran, and strong enough in the BphAE{sub RR41}:2-chlorodibenzofuran to help prevent substrate movement during the catalytic reaction.

  14. Advances and perspective in bioremediation of polychlorinated biphenyl-contaminated soils.

    Science.gov (United States)

    Sharma, Jitendra K; Gautam, Ravindra K; Nanekar, Sneha V; Weber, Roland; Singh, Brajesh K; Singh, Sanjeev K; Juwarkar, Asha A

    2018-06-01

    In recent years, microbial degradation and bioremediation approaches of polychlorinated biphenyls (PCBs) have been studied extensively considering their toxicity, carcinogenicity and persistency potential in the environment. In this direction, different catabolic enzymes have been identified and reported for biodegradation of different PCB congeners along with optimization of biological processes. A genome analysis of PCB-degrading bacteria has led in an improved understanding of their metabolic potential and adaptation to stressful conditions. However, many stones in this area are left unturned. For example, the role and diversity of uncultivable microbes in PCB degradation are still not fully understood. Improved knowledge and understanding on this front will open up new avenues for improved bioremediation technologies which will bring economic, environmental and societal benefits. This article highlights on recent advances in bioremediation of PCBs in soil. It is demonstrated that bioremediation is the most effective and innovative technology which includes biostimulation, bioaugmentation, phytoremediation and rhizoremediation and acts as a model solution for pollution abatement. More recently, transgenic plants and genetically modified microorganisms have proved to be revolutionary in the bioremediation of PCBs. Additionally, other important aspects such as pretreatment using chemical/physical agents for enhanced biodegradation are also addressed. Efforts have been made to identify challenges, research gaps and necessary approaches which in future, can be harnessed for successful use of bioremediation under field conditions. Emphases have been given on the quality/efficiency of bioremediation technology and its related cost which determines its ultimate acceptability.

  15. Congener-specific egg contribution of polychlorinated biphenyls to nestlings in two passerine species

    Energy Technology Data Exchange (ETDEWEB)

    Maul, Jonathan D., E-mail: jonathan.maul@tiehh.ttu.ed [Department of Environmental Toxicology, Institute of Environmental and Human Health (TIEHH), Texas Tech University, Lubbock, TX 79409 (United States); Schuler, Lance J. [Fisheries and Illinois Aquaculture Center and Department of Zoology, Southern Illinois University, Carbondale, IL 62901 (United States); Halbrook, Richard S. [Cooperative Wildlife Research Laboratory and Department of Zoology, Southern Illinois University, Carbondale, IL 62901 (United States); Lydy, Michael J. [Fisheries and Illinois Aquaculture Center and Department of Zoology, Southern Illinois University, Carbondale, IL 62901 (United States)

    2010-08-15

    Quantifying polychlorinated biphenyl (PCB) residues in nestlings of avian species is a common method for assessing trophic transfer and risk at PCB-contaminated sites. The proportion of nestling PCB mass due to maternal transfer is often accounted for by subtracting total PCB mass in eggs from nestlings. However, variation in physicochemical properties and metabolism among congeners may lead to differences between egg contribution based on total PCBs and dioxin-like congeners. We examined congener-specific variation in contribution of PCBs from eggs to nestlings in tree swallows and European starlings. Egg contribution of total PCB mass was 14.3 and 16.2%, respectively, whereas contribution based on dioxin-like congeners was 14.8 and 13.6%, respectively. These data suggest that using total PCB mass in eggs to adjust estimates of PCB accumulation in nestlings may not reflect patterns for dioxin-like congeners, potentially over or under-estimating the risk of toxicity of PCBs. - Congener-specific contribution of PCBs from egg to nestlings was examined.

  16. Polychlorinated biphenyls in polysulfide sealants-Occurrence and emission from a landfill station

    International Nuclear Information System (INIS)

    Persson, N. Johan; Pettersen, Harald; Ishaq, Rasha; Axelman, Johan; Bandh, Cecilia; Broman, Dag; Zebuehr, Yngve; Hammar, Tommy

    2005-01-01

    Approximately 80 000 kg polysulfide sealant containing 10 000-18 000 kg polychlorinated biphenyls (PCB) was deposited at a Swedish municipal landfill station during 1965-1973. Investigations during 1994 showed that soil layers underneath the landfill had concentration of PCB not alarmingly high. The concentration of PCB congeners in ground water samples was elevated 4-750 times compared to a reference sample. Based on samples of ground water, leachate water, and flux chambers measuring evaporation of PCB from the landfill surface, the emission of PCB was estimated to be 1 g ΣPCB/yr. This very low rate was attributed to the high sorptive capacity of the sealant. Compared to a reference site, the evaporation flux was elevated for the most volatile congeners, but factors 20-1400 lower than from another landfill which was contaminated with PCB in paper-pulp fibres. - From a municipal 2-ha landfill containing 10-18 tonnes of ΣPCB bound in polysulfide sealants, only 1 g per year escape to the surroundings

  17. Polychlorinated biphenyls in freshwater salmonids from the Kerguelen Islands in the Southern Ocean

    International Nuclear Information System (INIS)

    Jaffal, A.; Givaudan, N.; Betoulle, S.; Terreau, A.; Paris-Palacios, S.; Biagianti-Risbourg, S.; Beall, E.; Roche, H.

    2011-01-01

    The Subantarctic Kerguelen Islands (49 o S, 70 o E) contain freshwater ecosystems among the most isolated in the world. Concentrations of polychlorinated biphenyls (PCBs) were assessed in the muscle of 48 brook trout and 38 brown trout caught during summer and spring 2006 in the rivers, lakes and ponds of Kerguelen. The sum of 29 PCBs averaged 404 and 358 ng g -1 lipid, and dioxin-like PCB was 19 and 69 ng g -1 lipid, in brook and brown trout, respectively. The values showed a high variability and some fish accumulated PCBs at levels similar to those of fish from impacted areas. While inter-sex differences were limited, the season and the morphotype appeared to have the most influence. Fish captured in summer had muscle PCB concentrations about three times higher than those caught in spring and the 'river' morphotype of brook trout showed the highest PCB levels. - Highlights: → First assessment of PCB contamination of biota in Kerguelen Islands, Sub-Antarctica. → PCB bioaccumulation level in trout varies from very high to undetectable. → Habitat and morphotype are the most influential factors on the variability. → Distribution pattern of PCBs in the muscle of fish is morphotype dependent. - Salmonids in hydrosystems of the Kerguelen Islands (Southern Ocean) show a high PCB bioaccumulation.

  18. High-pressure extraction of polychlorinated biphenyls from soils and other fine-grained solids

    International Nuclear Information System (INIS)

    Markowz, G.

    1996-12-01

    Four doped and three really contaminated samples were subjected to high-pressure PCB (polychlorinated biphenyl) extraction in a laboratory-scale experimental plant using CO 2 (carbon dioxide) as solvent. The PCB levels (sum out of the six key substances) of the real samples were 2.6, 6.8, and 139 mg/kg. The success of the cleaning process was determined by measuring the residual PCB levels in the soil after the extraction. Parameters were varied and samples were taken selectively from various points in the bed (length 270 mm, diameter 14 mm, weighed - in soil 50-60 g) in order to gain an idea of the effects of upscaling. The following parameters were varied: extraction temperature 40-90 C; extraction pressure 200-300 bar; CO 2 flow rate 3.6-14.6 g/min; CO 2 quantity 0-328 g; degree of contamination (doped samples) 12-60 mg/kg; soil moisture 0-15%; particle size 0-2000 μm; entraining agent methanol, ethanol, acetone; proportion of entraining agent 0-7.5% by weight. Furthermore the influence of moisture at the time of doping on extraction was examined. (orig./ABI) [de

  19. An oxyde mixture fuel containing uranium and plutonium dioxides and process to obtain this oxyde mixture

    International Nuclear Information System (INIS)

    Hannerz, K.

    1976-01-01

    An oxide-mixture fuel containing uranium and plutonium dioxides having the slage of spherical, or nearly spherical, oxide-mixture particles with a diameter within the range of from 0.2 to 2 mn charactarized in that each oxide-mixture particles is provided with an outer layer comprising mainly UO2, the thickness of which is at least 0.05; whereas the inner portion of the oxide-mixture particles comprises mainly PUO 2

  20. Process Dissociation and Mixture Signal Detection Theory

    Science.gov (United States)

    DeCarlo, Lawrence T.

    2008-01-01

    The process dissociation procedure was developed in an attempt to separate different processes involved in memory tasks. The procedure naturally lends itself to a formulation within a class of mixture signal detection models. The dual process model is shown to be a special case. The mixture signal detection model is applied to data from a widely…

  1. Buffer gas cooling and mixture analysis

    Science.gov (United States)

    Patterson, David S.; Doyle, John M.

    2018-03-06

    An apparatus for spectroscopy of a gas mixture is described. Such an apparatus includes a gas mixing system configured to mix a hot analyte gas that includes at least one analyte species in a gas phase into a cold buffer gas, thereby forming a supersaturated mixture to be provided for spectroscopic analysis.

  2. Unfolding the potential of wheat cultivar mixtures

    DEFF Research Database (Denmark)

    Borg, J.; Kiær, Lars Pødenphant; Lecarpentier, C.

    2018-01-01

    and they are not encouraged by advisory services. Based on the methodology developed by Kiær et al. (2009), we achieved a meta-analysis of cultivar mixtures in wheat. Among the 120 publications dedicated to wheat, we selected 32 studies to analyze various factors that may condition the success or failure of wheat mixtures...

  3. Separation of organic azeotropic mixtures by pervaporation

    Energy Technology Data Exchange (ETDEWEB)

    Baker, R.W.

    1991-12-01

    Distillation is a commonly used separation technique in the petroleum refining and chemical processing industries. However, there are a number of potential separations involving azetropic and close-boiling organic mixtures that cannot be separated efficiently by distillation. Pervaporation is a membrane-based process that uses selective permeation through membranes to separate liquid mixtures. Because the separation process is not affected by the relative volatility of the mixture components being separated, pervaporation can be used to separate azetropes and close-boiling mixtures. Our results showed that pervaporation membranes can be used to separate azeotropic mixtures efficiently, a result that is not achievable with simple distillation. The membranes were 5--10 times more permeable to one of the components of the mixture, concentrating it in the permeate stream. For example, the membrane was 10 times more permeable to ethanol than methyl ethyl ketone, producing 60% ethanol permeate from an azeotropic mixture of ethanol and methyl ethyl ketone containing 18% ethanol. For the ethyl acetate/water mixture, the membranes showed a very high selectivity to water (> 300) and the permeate was 50--100 times enriched in water relative to the feed. The membranes had permeate fluxes on the order of 0.1--1 kg/m{sup 2}{center dot}h in the operating range of 55--70{degrees}C. Higher fluxes were obtained by increasing the operating temperature.

  4. Fibril assembly in whey protein mixtures

    NARCIS (Netherlands)

    Bolder, S.G.

    2007-01-01

    The objective of this thesis was to study fibril assembly in mixtures of whey proteins. The effect of the composition of the protein mixture on the structures and the resulting phase behaviour was investigated. The current work has shown that beta-lactoglobulin is responsible for the fibril assembly

  5. Process of decomposing an oil mixture

    Energy Technology Data Exchange (ETDEWEB)

    Kubierschky, K

    1917-12-02

    A process is described for the decomposition of oil mixtures, and the like, by means of alcohol, characterized in that the subject mixture is brought into solution in high-grade alcohol, and this solution is washed countercurrent with dilute alcohol.

  6. Mixture Modeling: Applications in Educational Psychology

    Science.gov (United States)

    Harring, Jeffrey R.; Hodis, Flaviu A.

    2016-01-01

    Model-based clustering methods, commonly referred to as finite mixture modeling, have been applied to a wide variety of cross-sectional and longitudinal data to account for heterogeneity in population characteristics. In this article, we elucidate 2 such approaches: growth mixture modeling and latent profile analysis. Both techniques are…

  7. Intelligent gas-mixture flow sensor

    NARCIS (Netherlands)

    Lammerink, Theodorus S.J.; Dijkstra, Fred; Houkes, Z.; van Kuijk, J.C.C.; van Kuijk, Joost

    A simple way to realize a gas-mixture flow sensor is presented. The sensor is capable of measuring two parameters from a gas flow. Both the flow rate and the helium content of a helium-nitrogen gas mixture are measured. The sensor exploits two measurement principles in combination with (local)

  8. Shock formation in mixtures of fluids

    International Nuclear Information System (INIS)

    Virgopia, N.; Ferraioli, F.

    1987-01-01

    The problem of weak-discontinuity propagation in mixtures of two ideal fluids is examined. The presence of exchenge of momentum reduces or enhances the time for shock formation depending on the machanism with whom the exchange of momentum takes place. Numerical evaluation are also presented for mixtures of nitrogen and oxygen simulating dry-air models

  9. The Modified Enskog Equation for Mixtures

    NARCIS (Netherlands)

    Beijeren, H. van; Ernst, M.H.

    1973-01-01

    In a previous paper it was shown that a modified form of the Enskog equation, applied to mixtures of hard spheres, should be considered as the correct extension of the usual Enskog equation to the case of mixtures. The main argument was that the modified Enskog equation leads to linear transport

  10. Mixture toxicity of PBT-like chemicals

    DEFF Research Database (Denmark)

    Syberg, Kristian; Dai, Lina; Ramskov, Tina

    addition is a suitable model for default estimations of mixture effects. One of the major challenges is therefore how to select specific chemicals for actual mixture toxicity assessments. Persistant chemicals are likely to be present in the environment for an extended period of time, thus increasing...... the likelihood of them being present in environmentally found mixtures. Persistant, bioaccumulative and toxic (PBT) chemicals are therefore a highly relevant group of chemicals to consider for mixture toxicity regulation. The present study evaluates to what extent a number of PBT-like chemicals posess concern...... beyond that of the individual components. Firstly, the effects of three chemicals with PBT-like properties (acetyl cedrene, pyrene and triclosan) was examined on the freshwater snail, Potamopyrgus antipodarum. Secondly, mixture bioaccumulation of the same three chemicals were assessed experimentally...

  11. A binary mixture operated heat pump

    International Nuclear Information System (INIS)

    Hihara, E.; Saito, T.

    1991-01-01

    This paper evaluates the performance of possible binary mixtures as working fluids in high- temperature heat pump applications. The binary mixtures, which are potential alternatives of fully halogenated hydrocarbons, include HCFC142b/HCFC22, HFC152a/HCFC22, HFC134a/HCFC22. The performance of the mixtures is estimated by a thermodynamic model and a practical model in which the heat transfer is considered in heat exchangers. One of the advantages of binary mixtures is a higher coefficient of performance, which is caused by the small temperature difference between the heat-sink/-source fluid and the refrigerant. The mixture HCFC142b/HCFC22 is promising from the stand point of thermodynamic performance

  12. Radiolytic decomposition of water-ethanol mixtures

    International Nuclear Information System (INIS)

    Baquey, Charles

    1968-07-01

    This research thesis addresses the study of the behaviour of binary mixtures submitted to ionizing radiations, and notably aims, by studying the case of water-ethanol mixtures, at verifying solutions proposed by previously published works on the origin of hydrogen atoms and of molecular hydrogen, on the intervention of excited atoms, and on the origin of products appearing under radiolysis. The experimental part of this work consists in the dosing of products formed in water-ethanol mixtures irradiated in presence or absence of nitrate, hydrogen, hydrocarbon, acetaldehyde, 2-3 butanediol and nitrite. Results are discussed and interpreted in terms of acetaldehyde efficiency, 2-3 butanediol efficiencies, and hydrocarbon efficiencies in pure ethanol, and in water-ethanol mixtures. The influence of the presence of nitrate ions in mixtures is also discussed

  13. Deformation Properties and Fatigue of Bituminous Mixtures

    Directory of Open Access Journals (Sweden)

    Frantisek Schlosser

    2013-01-01

    Full Text Available Deformation properties and fatigue performance are important characteristics of asphalt bound materials which are used for construction of pavement layers. Viscoelastic asphalt mixtures are better characterized via dynamic tests. This type of tests allows us to collate materials with regard to axle vibrations which lie usually in the range of 6 Hz–25 Hz for standard conditions. Asphalt modified for heat sensitivity in the range from −20°C to +60°C has significant impact on the overall characteristics of the mixture. Deformation properties are used as inputs for empirical mixture design, and fatigue performance of asphalt mixtures reflects the parameters of functional tests. Master curves convey properties of asphalt mixtures for various conditions and allow us to evaluate them without the need of time expensive testing.

  14. Behavioral effects of pre- and postnatal exposure to a mixture of low chlorinated PCBs in rats.

    Science.gov (United States)

    Lilienthal, H; Neuf, M; Munoz, C; Winneke, G

    1990-10-01

    Polychlorinated biphenyl (PCB)-treated Wistar rats were tested on three different behavioral paradigms. Animals were pre- and postnatally exposed to a technical mixture of PCBs with a chlorine content of 42%. Exposure levels were 0, 5, or 30 mg/kg diet. These conditions did not affect the health of the dams, the litter size or weight, or the physical development of the offspring. Relative liver weights in the offspring, however, were elevated in a dose-dependent manner. Open-field ambulation, active avoidance learning, and operant conditioning on a fixed interval 30-sec schedule (FI-30-sec) were used to evaluate PCB-induced behavioral alterations. Ambulation was increased in 30-mg-treated rats at Day 22, but not at Day 120. There were more avoidance responses and intertrial responses in the 30-mg group than in both other groups. On the FI-30-sec schedule slightly more reactions were emitted by the 30-mg group during the first 10 sec of the interval than by the other animals. More pronounced, however, were the differences between groups in the temporal pattern of responses within the 30-sec interval. It is concluded that in rats PCB exposure causes consistent alterations in all of the tested activity-dependent behaviors.

  15. Adaptation mechanisms of bacteria during the degradation of polychlorinated biphenyls in the presence of natural and synthetic terpenes as potential degradation inducers

    Energy Technology Data Exchange (ETDEWEB)

    Zoradova-Murinova, Slavomira; Dudasova, Hana; Lukacova, Lucia; Certik, Milan; Dercova, Katarina [Slovak Univ. of Technology, Bratislava (Slovakia). Inst. of Biotechnology and Food Science; Silharova, Katarina; Vrana, Branislav [Water Research Institute, Bratislava (Slovakia)

    2012-06-15

    In this study, we examined the effect of polychlorinated biphenyls (PCBs) in the presence of natural and synthetic terpenes and biphenyl on biomass production, lipid accumulation, and membrane adaptation mechanisms of two PCB-degrading bacterial strains Pseudomonas stutzeri and Burkholderia xenovorans LB400. According to the results obtained, it could be concluded that natural terpenes, mainly those contained in ivy leaves and pine needles, decreased adaptation responses induced by PCBs in these strains. The adaptation processes under investigation included growth inhibition, lipid accumulation, composition of fatty acids, cis/trans isomerization, and membrane saturation. Growth inhibition effect decreased upon addition of these natural compounds to the medium. The amount of unsaturated fatty acids that can lead to elevated membrane fluidity increased in both strains after the addition of the two natural terpene sources. The cells adaptation changes were more prominent in the presence of carvone, limonene, and biphenyl than in the presence of natural terpenes, as indicated by growth inhibition, lipid accumulation, and cis/trans isomerization. Addition of biphenyl and carvone simultaneously with PCBs increased the trans/cis ratio of fatty acids in membrane fractions probably as a result of fluidizing effects of PCBs. This stimulation is more pronounced in the presence of PCBs as a sole carbon source. This suggests that PCBs alone have a stronger effect on bacterial membrane adaptation mechanisms than when added together with biphenyl or natural or synthetic terpenes. (orig.)

  16. [Polychlorinated biphenyls in fractions of wheat grains and in selected bakery products].

    Science.gov (United States)

    Brandt, Elzbieta; Pietrzak-Fiećko, Renata; Smoczyński, S S

    2012-01-01

    Polychlorinated biphenyls (PCBs) form a group of synthetic aromatic chemical compounds, commonly occurring in the environment as a result of industrialisation. Despite the ban on PCBs production, their wide application in the past resulted in their common occurrence in all elements of the environment. The lipophilic nature of the compounds resulting in their accumulation in live organisms and in the human body may trigger many harmful effects. The aim of this study was to determine the PCBs content in the selected species of wheat and in bakery products. The studies aiming at confirming possible correlation between the size of the grain of the selected species of wheat and the content of polychlorinated biphenyls were presented in this paper. Moreover, PCBs concentration in cereals' grains and in bread was compared. The PCBs content was defined in different sizes of grains species of wheat i.e. Opatka, Zyta, Elena and Almari. The study included also two kinds of wheat bread. PCBs were determined after the extraction with n-hexane followed by sulphuric acid hydrolysis. Gas chromatography analysis was conducted on a PU 4600 Unicam apparatus with an electron capture detector. The large variations in PCBs content depending on the grain size were confirmed. In the Opatka species the increase in the content of all determined congeners and the size of grain was confirmed. The lowest PCBs concentrations were in smallest grains (0,0090 mg/kg of fat), and the highest in the largest grains (0,0264 mg/kg of fat). In Zyta species PCBs content was also lowest in the smallest grains, however these results were not statistically significant. In the Elena species the increase in the PCBs content together with the increase in the grain size was confirmed. Basing on the determination coefficient it was found that the concentration of PCBs depends on the size of grains in 24%. The highest concentration of PCBs (0,0366 mg/kg of fat) was found in the largest grains, however differences

  17. Multi-temperature mixture of fluids

    Directory of Open Access Journals (Sweden)

    Ruggeri Tommaso

    2009-01-01

    Full Text Available We present a survey on some recent results concerning the different models of a mixture of compressible fluids. In particular we discuss the most realistic case of a mixture when each constituent has its own temperature (MT and we first compare the solutions of this model with the one with a unique common temperature (ST . In the case of Eulerian fluids it will be shown that the corresponding (ST differential system is a principal subsystem of the (MT one. Global behavior of smooth solutions for large time for both systems will also be discussed through the application of the Shizuta-Kawashima condition. Then we introduce the concept of the average temperature of mixture based upon the consideration that the internal energy of the mixture is the same as in the case of a single-temperature mixture. As a consequence, it is shown that the entropy of the mixture reaches a local maximum in equilibrium. Through the procedure of Maxwellian iteration a new constitutive equation for non-equilibrium temperatures of constituents is obtained in a classical limit, together with the Fick's law for the diffusion flux. Finally, to justify the Maxwellian iteration, we present for dissipative fluids a possible approach of a classical theory of mixture with multi-temperature and we prove that the differences of temperatures between the constituents imply the existence of a new dynamical pressure even if the fluids have a zero bulk viscosity.

  18. Dehalogenation of Polybrominated Diphenyl Ethers and Polychlorinated Biphenyl by Bimetallic, Impregnated, and Nanoscale Zerovalent Iron

    Science.gov (United States)

    Zhuang, Yuan; Ahn, Sungwoo; Seyfferth, Angelia L.; Masue-Slowey, Yoko; Fendorf, Scott; Luthy, Richard G.

    2011-01-01

    Nanoscale zerovalent iron particles (nZVI), bimetallic nanoparticles (nZVI/Pd), and nZVI/Pd impregnated activated carbon (nZVI/Pd-AC) composite particles were synthesized and investigated for their effectiveness to remove polybrominated diphenyl ethers (PBDEs) and/or polychlorinated biphenyls (PCBs). Palladization of nZVI promoted the dehalogenation kinetics for mono- to tri-BDEs and 2,3,4-trichlorobiphenyl (PCB 21). Compared to nZVI, the iron-normalized rate constants for nZVI/Pd were about 2-, 3-, and 4-orders of magnitude greater for tri-, di-, and mono-BDEs, respectively, with diphenyl ether as a main reaction product. The reaction kinetics and pathways suggest an H-atom transfer mechanism. The reaction pathways with nZVI/Pd favor preferential removal of para-halogens on PBDEs and PCBs. X-ray fluorescence mapping of nZVI/Pd-AC showed that Pd mainly deposits on the outer part of particles, while Fe was present throughout the activated carbon particles. While BDE 21 was sorbed onto activated carbon composites quickly, debromination was slower compared to reaction with freely dispersed nZVI/Pd. Our XPS and chemical data suggest about 7% of the total iron within the activated carbon was zero-valent, which shows the difficulty with in-situ synthesis of a significant fraction of zero-valent iron in the micro-porous material. Related factors that likely hinder the reaction with nZVI/Pd-AC are the heterogenous distribution of nZVI and Pd on activated carbon and/or immobilization of hydrophobic organic contaminants at the adsorption sites thereby inhibiting contact with nZVI. PMID:21557574

  19. Independent review of inappropriate identification, storage and treatment methods of polychlorinated biphenyl waste streams

    International Nuclear Information System (INIS)

    1997-07-01

    The purpose of the review was to evaluate incidents involving the inappropriate identification, storage, and treatment methods associated with polychlorinated biphenyl (PCB) waste streams originating from the V-tank system at the Test Area North (TAN). The team was instructed to perform a comprehensive review of Lockheed Martin Idaho Technologies Company (LMITCO's) compliance programs related to these incidents to assess the adequacy and effectiveness of the management program in all respects including: adequacy of the waste management program in meeting all LMITCO requirements and regulations; adequacy of policies, plans, and procedures in addressing and implementing all federal and state requirements and regulations; and compliance status of LMITCO, LMITCO contract team members, and LMITCO contract/team member subcontractor personnel with established PCB management policies, plans, and procedures. The V-Tanks are part of an intermediate waste disposal system and are located at the Technical Support Facility (TSF) at TAN at the Idaho National Engineering and Environmental Laboratory (INEEL). The IRT evaluated how a waste was characterized, managed, and information was documented; however, they did not take control of wastes or ensure followup was performed on all waste streams that may have been generated from the V-Tanks. The team has also subsequently learned that the Environmental Restoration (ER) program is revising the plans for the decontamination and decommissioning of the intermediate waste disposal system based on new information listed and PCB wastes. The team has not reviewed those in-process changes. The source of PCB in the V-Tank is suspected to be a spill of hydraulic fluid in 1968

  20. Polychlorinated biphenyls in the exterior caulk of San Francisco Bay Area buildings, California, USA.

    Science.gov (United States)

    Klosterhaus, Susan; McKee, Lester J; Yee, Donald; Kass, Jamie M; Wong, Adam

    2014-05-01

    Extensive evidence of the adverse impacts of polychlorinated biphenyls (PCBs) to wildlife, domestic animals, and humans has now been documented for over 40 years. Despite the ban on production and new use of PCBs in the United States in 1979, a number of fish consumption advisories remain in effect, and there remains considerable uncertainty regarding ongoing environmental sources and management alternatives. Using a blind sampling approach, 25 caulk samples were collected from the exterior of ten buildings in the San Francisco Bay Area and analyzed for PCBs using congener-specific gas chromatography-mass spectrometry (GC-MS) and chlorine using portable X-ray fluorescence (XRF). PCBs were detected in 88% of the caulk samples collected from the study area buildings, with 40% exceeding 50 ppm. Detectable PCB concentrations ranged from 1 to 220,000 ppm. These data are consistent with previous studies in other cities that have identified relatively high concentrations of PCBs in concrete and masonry buildings built between 1950 and 1980. Portable XRF was not a good predictor of the PCB content in caulk and the results indicate that portable XRF analysis may only be useful for identifying caulk that contains low concentrations of Cl (≤ 10,000 ppm) and by extension low or no PCBs. A geographic information system-based approach was used to estimate that 10,500 kg of PCBs remain in interior and exterior caulk in buildings located in the study area, which equates to an average of 4.7 kg PCBs per building. The presence of high concentrations in the exterior caulk of currently standing buildings suggests that building caulk may be an ongoing source of PCBs to the San Francisco Bay Area environment. Further studies to expand the currently small international dataset on PCBs in caulking materials in buildings of countries that produced or imported PCBs appear justified in the context of both human health and possible ongoing environmental release. Copyright © 2014 Elsevier

  1. Polychlorinated biphenyl exposure and corticosterone levels in seven polar seabird species

    International Nuclear Information System (INIS)

    Tartu, S.; Angelier, F.; Bustnes, J.O.; Moe, B.; Hanssen, S.A.; Herzke, D.; Gabrielsen, G.W.; Verboven, N.; Verreault, J.; Labadie, P.; Budzinski, H.; Wingfield, J.C.

    2015-01-01

    The role of polychlorinated biphenyls (PCBs) on exposure-related endocrine effects has been poorly investigated in wild birds. This is the case for stress hormones including corticosterone (CORT). Some studies have suggested that environmental exposure to PCBs and altered CORT secretion might be associated. Here we investigated the relationships between blood PCB concentrations and circulating CORT levels in seven free-ranging polar seabird species occupying different trophic positions, and hence covering a wide range of PCB exposure. Blood ∑ 7 PCB concentrations (range: 61–115,632 ng/g lw) were positively associated to baseline or stress-induced CORT levels in three species and negatively associated to stress-induced CORT levels in one species. Global analysis suggests that in males, baseline CORT levels generally increase with increasing blood ∑ 7 PCB concentrations, whereas stress-induced CORT levels decrease when reaching high blood ∑ 7 PCB concentrations. This study suggests that the nature of the PCB-CORT relationships may depend on the level of PCB exposure. - Highlights: • Relationships between PCBs and stress hormones (CORT) are not well known in birds. • We measured blood PCBs, baseline and stress-induced CORT in seven seabird species. • ∑PCB was positively associated to baseline or stress-induced CORT in three species. • ∑PCBs was negatively linked to stress-induced CORT in the most contaminated species. • The nature of the PCB-CORT relationships may depend on the level of PCB exposure. - In polar seabird species, the relationship between PCB and CORT concentrations may be related to the levels of contamination

  2. Allee effect in polar bears: a potential consequence of polychlorinated biphenyl contamination.

    Science.gov (United States)

    Pavlova, Viola; Nabe-Nielsen, Jacob; Dietz, Rune; Sonne, Christian; Grimm, Volker

    2016-11-30

    Polar bears (Ursus maritimus) from East Greenland and Svalbard exhibited very high concentrations of polychlorinated biphenyls (PCBs) in the 1980s and 1990s. In Svalbard, slow population growth during that period was suspected to be linked to PCB contamination. In this case study, we explored how PCBs could have impacted polar bear population growth and/or male reproductive success in Svalbard during the mid-1990s by reducing the fertility of contaminated males. A dose-response relationship linking the effects of PCBs to male polar bear fertility was extrapolated from studies of the effects of PCBs on sperm quality in rodents. Based on this relationship, an individual-based model of bear interactions during the breeding season predicted fertilization success under alternative assumptions regarding male-male competition for females. Contamination reduced pregnancy rates by decreasing the availability of fertile males, thus triggering a mate-finding Allee effect, particularly when male-male competition for females was limited or when infertile males were able to compete with fertile males for females. Comparisons of our model predictions on age-dependent reproductive success of males with published empirical observations revealed that the low representation of 10-14-year-old males among breeding males documented in Svalbard in mid-1990s could have resulted from PCB contamination. We conclude that contamination-related male infertility may lead to a reduction in population growth via an Allee effect. The magnitude of the effect is largely dependent on the population-specific mating system. In eco-toxicological risk assessments, appropriate consideration should therefore be given to negative effects of contaminants on male fertility and male mating behaviour. © 2016 The Author(s).

  3. Polychlorinated biphenyl and heavy metal exposures among fishermen in the Straits of Malacca: neurobehavioural performance.

    Science.gov (United States)

    Mohamad, Alina; Azlan, Azrina; Adon, Mohd Yusoff; Khoo, Hock Eng; Razman, Muhammad Rizal

    2015-01-01

    The aim of this study was to determine the level of exposure to polychlorinated biphenyls (PCBs) and selected heavy metals among fishermen via dietary intake of fish and other seafood from the eastern coast along the Straits of Malacca. This study determined the neurobehavioural performances (based on neurobehavioural core test battery scores) of the fishermen and evaluated the correlations between scores of neurobehavioural core test battery and exposure factors. Ninety fishermen participated in the study. The total fish intakes of the fishermen were measured using a set of food frequency questionnaires. The PCBs contents in the seafood samples ranged between 0.2 and 0.6 pg/g fresh sample. The concentrations of mercury (Hg), arsenic (As), cadmium (Cd), and lead (Pb) in the seafood samples were 1.1-5.4, 0.3-4.4, 0.6-36.1, and 0.02-0.3 μg/g fresh sample, respectively. The PCBs, Hg, As, Cd, and Pb exposures of the fishermen was estimated to be 2.8, 0.02, 4.5, 0.09, and 0.5 pg/kg body weight/day, respectively. PCB and heavy metal exposures through dietary intake of fish and seafood were within the tolerable daily limits. The results of neurobehavioural core test battery revealed that the neurobehavioural performances of the fishermen were not affected due to PCB and heavy metal intoxication. No correlations were found between the exposure and neurobehavioural performance among the fishermen. These data are useful for policy makers to assure the safety and quality of seafood in relation to sea pollution. Although the levels of exposure were low, periodic assessment of the quality of fish and fish products is required due to the polluted seawater.

  4. Historical reconstruction of polychlorinated biphenyl (PCB) exposures for workers in a capacitor manufacturing plant.

    Science.gov (United States)

    Hopf, Nancy B; Ruder, Avima M; Waters, Martha A

    2014-05-01

    We developed a semiquantitative job exposure matrix (JEM) for workers exposed to polychlorinated biphenyls (PCBs) at a capacitor manufacturing plant from 1946 to 1977. In a recently updated mortality study, mortality of prostate and stomach cancer increased with increasing levels of cumulative exposure estimated with this JEM (trend p values = 0.003 and 0.04, respectively). Capacitor manufacturing began with winding bales of foil and paper film, which were placed in a metal capacitor box (pre-assembly), and placed in a vacuum chamber for flood-filling (impregnation) with dielectric fluid (PCBs). Capacitors dripping with PCB residues were then transported to sealing stations where ports were soldered shut before degreasing, leak testing, and painting. Using a systematic approach, all 509 unique jobs identified in the work histories were rated by predetermined process- and plant-specific exposure determinants; then categorized based on the jobs' similarities (combination of exposure determinants) into 35 job exposure categories. The job exposure categories were ranked followed by a qualitative PCB exposure rating (baseline, low, medium, and high) for inhalation and dermal intensity. Category differences in other chemical exposures (solvents, etc.) prevented further combining of categories. The mean of all available PCB concentrations (1975 and 1977) for jobs within each intensity rating was regarded as a representative value for that intensity level. Inhalation (in microgram per cubic milligram) and dermal (unitless) exposures were regarded as equally important. Intensity was frequency adjusted for jobs with continuous or intermittent PCB exposures. Era-modifying factors were applied to the earlier time periods (1946-1974) because exposures were considered to have been greater than in later eras (1975-1977). Such interpolations, extrapolations, and modifying factors may introduce non-differential misclassification; however, we do believe our rigorous method

  5. Seasonal atmospheric deposition variations of polychlorinated biphenyls (PCBs) and comparison of some deposition sampling techniques.

    Science.gov (United States)

    Birgül, Askın; Tasdemir, Yücel

    2011-03-01

    Ambient air and bulk deposition samples were collected between June 2008 and June 2009. Eighty-three polychlorinated biphenyl (PCB) congeners were targeted in the samples. The average gas and particle PCB concentrations were found as 393 ± 278 and 70 ± 102 pg/m(3), respectively, and 85% of the atmospheric PCBs were in the gas phase. Bulk deposition samples were collected by using a sampler made of stainless steel. The average PCB bulk deposition flux value was determined as 6,020 ± 4,350 pg/m(2) day. The seasonal bulk deposition fluxes were not statistically different from each other, but the summer flux had higher values. Flux values differed depending on the precipitation levels. The average flux value in the rainy periods was 7,480 ± 4,080 pg/m(2) day while the average flux value in dry periods was 5,550 ± 4,420 pg/m(2) day. The obtained deposition values were lower than the reported values given for the urban and industrialized areas, yet close to the ones for the rural sites. The reported deposition values were also influenced by the type of the instruments used. The average dry deposition and total deposition velocity values calculated based on deposition and concentration values were found as 0.23 ± 0.21 and 0.13 ± 0.13 cm/s, respectively.

  6. Polychlorinated biphenyls and pesticides in surficial coastal sediments of the Ligurian Sea

    Energy Technology Data Exchange (ETDEWEB)

    Bertolotto, R.M.; Cuneo, C.; Albanese, S. [ARPAL, Direzione Scientifica, Genova (Italy); Magherini, A. [ARPAL, Dipartimento di Genova, Genova (Italy); Frignani, M.; Bellucci, L.G.; Alvarado-Aguilar, D. [ISMAR, Sezione di Geologia Marina, Bologna (Italy)

    2004-09-15

    Polychlorinated biphenyls (PCBs) and chlorinated pesticides, such as DDT and its analogues, are organic contaminants widespread throughout the terrestrial and oceanic environments due to their common use and their resistance to degradation. Since harmful effects have been associated to these chemicals and well documented, they are classified as priority pollutants by both the US Environmental Protection Agency (EPA) and the European Union. Because of the very low solubility in water and the tendency to adsorb onto sediment particles, the ultimate fate of both PCBs and DDTs in the marine environment is the incorporation into sediments. Hence, the concentrations of these chlorinate chemicals in bottom sediments can provide an insight on the quality of the environment and the potential threat to marine organisms and human beings. The Ligurian Sea belongs to the north part of the western Mediterranean. The coastal morphology of the Liguria Region is rather variable, and frequently cliffs drop sheer to the sea. The limited width of the coastal zone, comprised between the sea and the mountains, determined a gathering of the urban areas with a consequent concentration of both civil and industrial presence in a narrow but highly populated territory. In particular Genova, but also other cities have a long history of industrial and harbour activities, whereas long tracts of the coast are dedicated to tourism. The circulation of the Ligurian Sea is rather well known. In particular, surface and intermediate currents follow a cyclonic circulation. However local circulation is the true responsible of the dispersion of sediment material along the coast, and these alongshore currents often cause an eastward oriented transport. The Ligurian coastal zone is very developed, and hosts all sort of industrial, agricultural and tourist activities that can be sources of persistent organochlorine chemicals. Therefore, the purpose of this study was to assess concentrations, distributions

  7. Neurodevelopmental toxicity of prenatal polychlorinated biphenyls (PCBs by chemical structure and activity: a birth cohort study

    Directory of Open Access Journals (Sweden)

    Park Hye-Youn

    2010-08-01

    Full Text Available Abstract Background Polychlorinated biphenyls (PCBs are ubiquitous environmental toxins. Although there is growing evidence to support an association between PCBs and deficits of neurodevelopment, the specific mechanisms are not well understood. The potentially different roles of specific PCB groups defined by chemical structures or hormonal activities e.g., dioxin-like, non-dioxin like, or anti-estrogenic PCBs, remain unclear. Our objective was to examine the association between prenatal exposure to defined subsets of PCBs and neurodevelopment in a cohort of infants in eastern Slovakia enrolled at birth in 2002-2004. Methods Maternal and cord serum samples were collected at delivery, and analyzed for PCBs using high-resolution gas chromatography. The Bayley Scales of Infant Development -II (BSID were administered at 16 months of age to over 750 children who also had prenatal PCB measurements. Results Based on final multivariate-adjusted linear regression model, maternal mono-ortho-substituted PCBs were significantly associated with lower scores on both the psychomotor (PDI and mental development indices (MDI. Also a significant association between cord mono-ortho-substituted PCBs and reduced PDI was observed, but the association with MDI was marginal (p = 0.05. Anti-estrogenic and di-ortho-substituted PCBs did not show any statistically significant association with cognitive scores, but a suggestive association between di-ortho-substituted PCBs measured in cord serum and poorer PDI was observed. Conclusion Children with higher prenatal mono-ortho-substituted PCB exposures performed more poorly on the Bayley Scales. Evidence from this and other studies suggests that prenatal dioxin-like PCB exposure, including mono-ortho congeners, may interfere with brain development in utero. Non-dioxin-like di-ortho-substituted PCBs require further investigation.

  8. Interacting influence of potassium and polychlorinated biphenyl on cortisol and aldosterone biosynthesis

    International Nuclear Information System (INIS)

    Li, L.-A.; Lin, Tsu-Chun Emma

    2007-01-01

    Giving human adrenocortical H295R cells 14 mM KCl for 24 h significantly induced not only aldosterone biosynthesis but also cortisol biosynthesis. Pre-treating the cells with polychlorinated biphenyl 126 (PCB126) further increased potassium-induced aldosterone and cortisol productions in a dose-dependent manner, but all examined concentrations of PCB126 had little effect on the yields of precursor steroids progesterone and 17-OH-progesterone. Subsequent examinations revealed that CYP11B1 and CYP11B2 genes, responsible for the respective final steps of the cortisol and aldosterone biosynthetic pathways, exhibited increased responsiveness to PCB126 under high potassium. While 10 -5 M PCB126 was needed to induce a significant increase in the basal mRNA abundance of either gene, PCB126 could enhance potassium-induced mRNA expression of CYP11B1 at 10 -7 M and CYP11B2 at 10 -9 M. Actually, potassium and PCB126 synergistically upregulated mRNA expression of both genes. Potassium raised the transcriptional rates of CYP11B1 and CYP11B2 probably through a conserved Ad5 cis-element, whereas PCB126 appeared to regulate these two genes at the post-transcriptional level. Positive potassium-PCB126 synergism was also detected in CYP11B2 enzyme activity estimated by aldosterone/progesterone ratio. In contrast, potassium and PCB126 increased CYP11B1 enzyme activity or cortisol/17-OH-progesterone ratio additively. Moreover, potassium improved the time effect of PCB126 on gene expression and enzyme activity of CYP11B2, but not the PCB126 time response of CYP11B1. These data demonstrated that potassium differentially enhanced the potency of PCB126 to induce CYP11B1- and CYP11B2-mediated steroidogenesis

  9. Organochlorine pesticides and polychlorinated biphenyls in fin whales (Balaenoptera physalus) from the Gulf of California.

    Science.gov (United States)

    Niño-Torres, Carlos Alberto; Zenteno-Savín, Tania; Gardner, Susan C; Urbán R, Jorge

    2010-08-01

    The present study reports unique data on concentrations of several classes of organochlorine pesticides and polychlorinated biphenyls in blubber biopsies from healthy living fin whales (Balaenoptera physalus) from the Gulf of California, Mexico, one of the most isolated and unstudied population in the world. OC levels in this population were generally lower than levels reported in fin whales from other regions. The rank order of OCs were SigmaDDTs (range from 300 to 2400 ng g(-1) lw) > SigmaPCBs (range from 40 to 290 ng g(-1) lw) > SigmaHCHs (range from or = SigmaCHLORs (from pesticide measured was the DDT metabolite, p,p'-DDE. The PCBs 138, 153, and 180 were the most abundant PCBs congeners found in the fin whales samples. Males had significant higher concentrations of SigmaOC, SigmaDDTs and SigmaPCBs than females (P < 0.05), although the p,p'-DDE/SigmaDDTs ratios were similar between the sexes. Although the OC concentrations found in this population were generally below the levels that would be expected to cause deleterious health effects, the maximum values observed (2700 ng g(-1) lw) in some animals were higher than those associated with reproductive effects in whales. Given the small population size and highly isolated characteristics of Gulf of California fin whales, health effects in individuals could readily translate into population-level effects. Future research on this topic will be necessary to better understand the role that these compounds may have on the health of this population.

  10. Environmental life-cycle comparisons of two polychlorinated biphenyl remediation technologies: incineration and base catalyzed decomposition.

    Science.gov (United States)

    Hu, Xintao; Zhu, Jianxin; Ding, Qiong

    2011-07-15

    Remediation action is critical for the management of polychlorinated biphenyl (PCB) contaminated sites. Dozens of remediation technologies developed internationally could be divided in two general categories incineration and non-incineration. In this paper, life cycle assessment (LCA) was carried out to study the environmental impacts of these two kinds of remediation technologies in selected PCB contaminated sites, where Infrared High Temperature Incineration (IHTI) and Base Catalyzed Decomposition (BCD) were selected as representatives of incineration and non-incineration. A combined midpoint/damage approach was adopted by using SimaPro 7.2 and IMPACTA2002+ to assess the human toxicity, ecotoxicity, climate change impact, and resource consumption from the five subsystems of IHTI and BCD technologies, respectively. It was found that the major environmental impacts through the whole lifecycle arose from energy consumption in both IHTI and BCD processes. For IHTI, primary and secondary combustion subsystem contributes more than 50% of midpoint impacts concerning with carcinogens, respiratory inorganics, respiratory organics, terrestrial ecotoxity, terrestrial acidification/eutrophication and global warming. In BCD process, the rotary kiln reactor subsystem presents the highest contribution to almost all the midpoint impacts including global warming, non-renewable energy, non-carcinogens, terrestrial ecotoxity and respiratory inorganics. In the view of midpoint impacts, the characterization values for global warming from IHTI and BCD were about 432.35 and 38.5 kg CO(2)-eq per ton PCB-containing soils, respectively. LCA results showed that the single score of BCD environmental impact was 1468.97 Pt while IHTI's score is 2785.15 Pt, which indicates BCD potentially has a lower environmental impact than IHTI technology in the PCB contaminated soil remediation process. Copyright © 2011 Elsevier B.V. All rights reserved.

  11. Polychlorinated biphenyl serum levels in subjects with hepatocellular carcinoma as compared with the general population

    Directory of Open Access Journals (Sweden)

    Claudia Zani

    2014-11-01

    Full Text Available Background. Polychlorinated biphenyls (PCBs have been recognized as human carcinogens and cause liver cancer in animal experimental studies. However, no study investigated their association with hepatocellular carcinoma (HCC so far.  This study aimed to evaluate the serum PCB concentration in HCC patients and in healthy subjects of the general population living in Brescia, North Italy, a highly industrialized area with heavy PCB environmental pollution due to the presence of a PCB producing factory. Methods. Lipid-adjusted PCB concentrations, computed as the sum of 24 congeners, were measured in the serum of 101 HCC patients and in 101 healthy subjects of the same age and gender.Results. Hepatitis B and C virus infection and history of heavy alcohol intake were found, alone and combined, in 87% of HCC patients. No difference was found in PCB serum concentration of HCC patients with and without, and according to, the major risk factors for liver disease. No significant difference was observed in serum total PCB concentration between HCC patients (median: 1081; range: 287.0-3182.0 ng/g lipid and healthy subjects (median: 1199.3; range: 225.7-22825 ng/g lipid. PCB congeners 118, 138, 153, 156, 180 and 194 were the only ones found over the detection limit in at least 30% of HCC patients. The serum level of PCB 118, but not that of other congeners, was higher in HCC patients than in healthy subjects.Conclusion. These findings  do not support the hypothesis that PCBs play an important role in HCC development, although a contribution by some specific congeners cannot be ruled out. 

  12. Riparian spiders as sentinels of polychlorinated biphenyl contamination across heterogeneous aquatic ecosystems

    Science.gov (United States)

    Kraus, Johanna M.; Gibson, Polly P.; Walters, David M.; Mills, Marc A.

    2017-01-01

    Riparian spiders are being used increasingly to track spatial patterns of contaminants in and fluxing from aquatic ecosystems.However, our understanding of the circumstances under which spiders are effective sentinels of aquatic pollution is limited. The present study tests the hypothesis that riparian spiders may be effectively used to track spatial patterns of sediment pollution by polychlorinated biphenyls (PCBs) in aquatic ecosystems with high habitat heterogeneity. The spatial pattern of ΣPCB concentrations in 2 common families of riparian spiders sampled in 2011 to 2013 generally tracked spatial variation in sediment ΣPCBs across all sites within the Manistique River Great Lakes Area of Concern (AOC), a rivermouth ecosystem located on the south shore of the Upper Peninsula, Manistique (MI,USA) that includes harbor, river, backwater, and lake habitats. Sediment ΣPCB concentrations normalized for total organic carbon explained 41% of the variation in lipid-normalized spider ΣPCB concentrations across 11 sites. Furthermore, 2 common riparian spider taxa (Araneidae and Tetragnathidae) were highly correlated (r2> 0.78) and had similar mean ΣPCB concentrations when averaged acrossall years. The results indicate that riparian spiders may be useful sentinels of relative PCB availability to aquatic and riparian food webs in heterogeneous aquatic ecosystems like rivermouths where habitat and contaminant variability may make the use of aquatic taxa lesseffective. Furthermore, the present approach appears robust to heterogeneity in shoreline development and riparian vegetation that support different families of large web-building spiders. Environ Toxicol Chem 2016;9999:1–9. Published 2016 Wiley Periodicals, Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

  13. Paddy field – A natural sequential anaerobic–aerobic bioreactor for polychlorinated biphenyls transformation

    International Nuclear Information System (INIS)

    Chen, Chen; Yu, Chunna; Shen, Chaofeng; Tang, Xianjin; Qin, Zhihui; Yang, Kai; Hashmi, Muhammad Zaffar; Huang, Ronglang; Shi, Huixiang

    2014-01-01

    The environmental pollution and health risks caused by the improper disposal of electric and electronic waste (e-waste) have become urgent issues for the developing countries. One of the typical pollutants, polychlorinated biphenyls (PCBs), is commonly found in farmland in Taizhou, a major hotspot of e-waste recycling in China. This study investigated the amount of PCB residue in local farmlands. Biotransformation of PCBs was further studied under different water management conditions in paddy field with or without rice cultivation, with a special focus on the alternating flooded and drying processes. It was found that paddy field improved the attenuation of PCBs, especially for highly chlorinated congeners. In the microcosm experiment, 40% or more of the initial total PCBs was removed after sequential flood–drying treatments, compared to less than 10% in the sterilized control and 20% in the constant-drying system. Variation in the quantity of PCBs degrading and dechlorinating bacterial groups were closely related to the alteration of anaerobic–aerobic conditions. These results suggested that alternating anoxic–oxic environment in paddy field led to the sequential aerobic–anaerobic transformation of PCBs, which provided a favorable environment for natural PCB attenuation. - Highlights: • Paddy fields hold significantly lower level of PCBs than drylands, especially highly-chlorinated PCBs. • Microbial dechlorination of PCBs is favored under flooded conditions in paddy field. • Aerobic biodegradation of PCBs is benefited under dry conditions in paddy field. • PCBs dechlorination rate is accelerated in rice planted paddy field compared to the unplanted one. • Alternating anoxic–oxic environment in paddy field led to the sequential aerobic–anaerobic transformation of PCBs. - Alternating anoxic–oxic environment led to the sequential aerobic–anaerobic transformation of PCBs in paddy field, which could act as a natural sequential anaerobic

  14. Progressive risk assessment of polychlorinated biphenyls through a Total Diet Study in the Korean population

    International Nuclear Information System (INIS)

    Shin, Eun-su; Nguyen, Khanh-Hoang; Kim, Jongchul; Kim, Cho-il; Chang, Yoon-Seok

    2015-01-01

    Human exposure to polychlorinated biphenyls (PCBs) from foods was investigated through a Total Diet Study (TDS) for the first time in Korea. A representative food list was developed from food intake data. Non-selected foods were also included in the TDS through the mapping process to anticipate practical risk assessment. For better representativeness, data (2008–2011) from the Korea National Health and Nutrition Examination Survey (KNHANES) were combined with the TDS data set. And also, we estimated the dietary exposure to PCBs from various food items using a ‘best-fit’ mapping process and assessed the differences in PCB exposures by sex and age. In this study, we examined total PCBs (62 congeners) including dioxin-like PCBs (DL-PCBs) and indicator PCBs, which are congeners that are mainly detected in various environmental matrices. The average dietary exposure (3.94 ng/kg body weight/day) that was estimated through food intake was 19.7% of the World Health Organization (WHO) recommendation. - Highlights: • A total of 282 samples, composed of the most consumed foodstuffs in Korea, were analysed and shown in detail. • The contamination status of total PCBs in food was assessed, through their various condition on cooking methods. • The dietary intakes of PCBs in various food groups were estimated in different region, gender and age groups. • The improved and systematic food selection process was applied such as ‘mapping process’. - This study is to ensure food safety through total analysis of PCBs with the improved risk assessment method.

  15. Latitudinal and seasonal capacity of the surface oceans as a reservoir of polychlorinated biphenyls

    International Nuclear Information System (INIS)

    Jurado, Elena; Lohmann, Rainer; Meijer, Sandra; Jones, Kevin C.; Dachs, Jordi

    2004-01-01

    The oceans play an important role as a global reservoir and ultimate sink of persistent organic pollutants (POPs) such as polychlorinated biphenyls congeners (PCBs). However, the physical and biogeochemical variables that affect the oceanic capacity to retain PCBs show an important spatial and temporal variability which have not been studied in detail, so far. The objective of this paper is to assess the seasonal and spatial variability of the ocean's maximum capacity to act as a reservoir of atmospherically transported and deposited PCBs. A level I fugacity model is used which incorporates the environmental variables of temperature, phytoplankton biomass, and mixed layer depth, as determined from remote sensing and from climatological datasets. It is shown that temperature, phytoplankton biomass and mixed layer depth influence the potential PCB reservoir of the oceans, being phytoplankton biomass specially important in the oceanic productive regions. The ocean's maximum capacities to hold PCBs are estimated. They are compared to a budget of PCBs in the surface oceans derived using a level III model that assumes steady state and which incorporates water column settling fluxes as a loss process. Results suggest that settling fluxes will keep the surface oceanic reservoir of PCBs well below its maximum capacity, especially for the more hydrophobic compounds. The strong seasonal and latitudinal variability of the surface ocean's storage capacity needs further research, because it plays an important role in the global biogeochemical cycles controlling the ultimate sink of PCBs. Because this modeling exercise incorporates variations in downward fluxes driven by phytoplankton and the extent of the water column mixing, it predicts more complex latitudinal variations in PCBs concentrations than those previously suggested. - Model calculations estimate the latitudinal and seasonal storage capacity of the surface oceans for PCBs

  16. Polychlorinated biphenyls exposure-induced insulin resistance is mediated by lipid droplet enlargement through Fsp27.

    Science.gov (United States)

    Kim, Hye Young; Kwon, Woo Young; Kim, Yeon A; Oh, Yoo Jin; Yoo, Seung Hee; Lee, Mi Hwa; Bae, Ju Yong; Kim, Jong-Min; Yoo, Young Hyun

    2017-06-01

    Although epidemiological and experimental studies demonstrated that polychlorinated biphenyls (PCBs) lead to insulin resistance, the mechanism underlying PCBs-induced insulin resistance has remained unsolved. In this study, we examined in vitro and in vivo effects of PCB-118 (dioxin-like PCB) and PCB-138 (non-dioxin-like PCB) on adipocyte differentiation, lipid droplet growth, and insulin action. 3T3-L1 adipocytes were incubated with PCB-118 or PCB-138 during adipocyte differentiation. For in vivo studies, C57BL/6 mice were administered PCB-118 or PCB-138 (37.5 mg/kg) by intraperitoneal injection and we examined adiposity and whole-body insulin action. PCB-118 and PCB-138 significantly promoted adipocyte differentiation and increased the lipid droplet (LD) size in 3T3-L1 adipocytes. In mice, both PCBs increased adipose mass and adipocyte size. Furthermore, both PCBs induced insulin resistance in vitro and in vivo. Expression of fat-specific protein 27 (Fsp27), which is localized to LD contact sites, was increased in PCB-treated 3T3-L1 adipocytes and mice. Depletion of Fsp27 by siRNA resulted in the inhibition of LD enlargement and attenuation of insulin resistance in PCB-treated 3T3-L1 adipocytes. An anti-diabetic drug, metformin, attenuated insulin resistance in PCB-treated 3T3-L1 adipocytes through the reduced expression of Fsp27 protein and LD size. This study suggests that PCB exposure-induced insulin resistance is mediated by LD enlargement through Fsp27.

  17. Polychlorinated biphenyls in two salt marsh sediments of the Venice Lagoon.

    Science.gov (United States)

    Mugnai, Cristian; Giuliani, Silvia; Bellucci, Luca G; Carraro, Claudio; Favotto, Maurizio; Frignani, Mauro

    2011-10-01

    Polychlorinated biphenyls (PCBs) were measured in two dated salt marsh cores of the Venice Lagoon to assess their input chronology and to evaluate the importance of atmospheric deposition as a source. Sampling sites were chosen in order to evidence the differences between areas located leeward and windward with respect to inputs originating in both the city of Venice and the industrial area. Concentrations of PCB indicators (0.13-15.6 ng g⁻¹) increased gradually from the 1930s, reached maxima from the 1950s to the late 1970s, and then decreased. PCB loadings to marshes are driven by both the atmospheric deposition and the resuspension of subtidal sediments, this latter being more important for heavier congeners. The downwind marsh recorded higher fluxes (0.06-9.72 ng cm⁻² year⁻¹) than the upwind one (0.01-0.53 ng cm⁻² year⁻¹). Recent fluxes are rather consistent with bulk deposition measurements. A higher contribution of CB-101 and CB-118 was detected in the intermediate layers of the downwind site, suggesting a different PCB source for the corresponding time interval. In the other marsh, PCBs showed a rather constant composition at all levels (mostly CB-153, CB-138 and CB-180), accounting for a regional influence. Deep layers showed an enrichment of higher chlorinated congeners at both sites, whereas recent samples conserve the patterns typical of surficial and subsurficial subtidal sediments. The scientific approach adopted in this research can be considered as a sort of methodological procedure for the determination of fluxes and pathways of PCBs through the study of marsh cores.

  18. Biphenyl liquid crystalline epoxy resin as a low-shrinkage resin-based dental restorative nanocomposite.

    Science.gov (United States)

    Hsu, Sheng-Hao; Chen, Rung-Shu; Chang, Yuan-Ling; Chen, Min-Huey; Cheng, Kuo-Chung; Su, Wei-Fang

    2012-11-01

    Low-shrinkage resin-based photocurable liquid crystalline epoxy nanocomposite has been investigated with regard to its application as a dental restoration material. The nanocomposite consists of an organic matrix and an inorganic reinforcing filler. The organic matrix is made of liquid crystalline biphenyl epoxy resin (BP), an epoxy resin consisting of cyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (ECH), the photoinitiator 4-octylphenyl phenyliodonium hexafluoroantimonate and the photosensitizer champhorquinone. The inorganic filler is silica nanoparticles (∼70-100 nm). The nanoparticles were modified by an epoxy silane of γ-glycidoxypropyltrimethoxysilane to be compatible with the organic matrix and to chemically bond with the organic matrix after photo curing. By incorporating the BP liquid crystalline (LC) epoxy resin into conventional ECH epoxy resin, the nanocomposite has improved hardness, flexural modulus, water absorption and coefficient of thermal expansion. Although the incorporation of silica filler may dilute the reinforcing effect of crystalline BP, a high silica filler content (∼42 vol.%) was found to increase the physical and chemical properties of the nanocomposite due to the formation of unique microstructures. The microstructure of nanoparticle embedded layers was observed in the nanocomposite using scanning and transmission electron microscopy. This unique microstructure indicates that the crystalline BP and nanoparticles support each other and result in outstanding mechanical properties. The crystalline BP in the LC epoxy resin-based nanocomposite was partially melted during exothermic photopolymerization, and the resin expanded via an order-to-disorder transition. Thus, the post-gelation shrinkage of the LC epoxy resin-based nanocomposite is greatly reduced, ∼50.6% less than in commercialized methacrylate resin-based composites. This LC epoxy nanocomposite demonstrates good physical and chemical properties and good biocompatibility

  19. Occurrence and exposure assessment of polychlorinated biphenyls and organochlorine pesticides from homemade baby food in Korea.

    Science.gov (United States)

    Jeong, Yunsun; Lee, Sunggyu; Kim, Sunmi; Choi, Sung-Deuk; Park, Jeongim; Kim, Hai-Joong; Lee, Jeong Jae; Choi, Gyuyeon; Choi, Sooran; Kim, Sungjoo; Kim, Su Young; Kim, Young Don; Cho, Geumjoon; Suh, Eunsook; Kim, Sung Koo; Eun, So-Hee; Eom, Soyong; Kim, Seunghyo; Kim, Gun-Ha; Choi, Kyungho; Kim, Sungkyoon; Moon, Hyo-Bang

    2014-02-01

    Data on the residue levels of persistent organic pollutants (POPs) in baby food samples are scarce. This is the first study to explore current contamination status and exposure assessment of organochlorines (OCs), including polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs), in baby food from Korea. In this study, the concentrations of OCs were determined in homemade baby food samples (n=100) collected from 6-, 9-, 12- and 15-month-old infant groups. The average concentrations of PCBs, dichloro-diphenyl-trichloroethanes (DDTs), hexachlorocyclohexanes (HCHs) and chlordanes (CHLs) in baby food samples were 37.5, 96.6, 26.0, and 13.2 pg/g fresh weight, respectively. The major compounds were CBs 28, 153, 52, and 33 for PCBs and p,p'-DDE, p,p'-DDT and β-HCH for OCPs. The contribution of DDTs to the total OC concentrations increased from 30% (6-month-old infants) to 67% (15-month-old infants) with increasing infant age, while the concentrations of PCBs, HCHs and CHLs gradually decreased with increasing infant age, suggesting that highest priority for risk reduction of DDTs. The estimated daily intakes (EDIs) of OCs in Korean infants from baby food consumption were lower than the thresholds proposed by the United States Environmental Protection Agency and Health Canada, implying limited potential health risks. However, considering simultaneous exposure from baby food and breast milk consumption, chlordanes and heptachlor epoxide posed potential health risks. Considering the importance of early development and the vulnerability of infants, it is essential to perform systematic monitoring and management programs of OCs in baby food for risk reduction in Korean infants. © 2013 Elsevier B.V. All rights reserved.

  20. Modeling Population-Level Consequences of Polychlorinated Biphenyl Exposure in East Greenland Polar Bears.

    Science.gov (United States)

    Pavlova, Viola; Grimm, Volker; Dietz, Rune; Sonne, Christian; Vorkamp, Katrin; Rigét, Frank F; Letcher, Robert J; Gustavson, Kim; Desforges, Jean-Pierre; Nabe-Nielsen, Jacob

    2016-01-01

    Polychlorinated biphenyls (PCBs) can cause endocrine disruption, cancer, immunosuppression, or reproductive failure in animals. We used an individual-based model to explore whether and how PCB-associated reproductive failure could affect the dynamics of a hypothetical polar bear (Ursus maritimus) population exposed to PCBs to the same degree as the East Greenland subpopulation. Dose-response data from experimental studies on a surrogate species, the mink (Mustela vision), were used in the absence of similar data for polar bears. Two alternative types of reproductive failure in relation to maternal sum-PCB concentrations were considered: increased abortion rate and increased cub mortality. We found that the quantitative impact of PCB-induced reproductive failure on population growth rate depended largely on the actual type of reproductive failure involved. Critical potencies of the dose-response relationship for decreasing the population growth rate were established for both modeled types of reproductive failure. Comparing the model predictions of the age-dependent trend of sum-PCBs concentrations in females with actual field measurements from East Greenland indicated that it was unlikely that PCB exposure caused a high incidence of abortions in the subpopulation. However, on the basis of this analysis, it could not be excluded that PCB exposure contributes to higher cub mortality. Our results highlight the necessity for further research on the possible influence of PCBs on polar bear reproduction regarding their physiological pathway. This includes determining the exact cause of reproductive failure, i.e., in utero exposure versus lactational exposure of offspring; the timing of offspring death; and establishing the most relevant reference metrics for the dose-response relationship.

  1. Sulfate radical-based degradation of polychlorinated biphenyls: Effects of chloride ion and reaction kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Guo-Dong [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Dionysiou, Dionysios D. [Environmental Engineering and Science Program, University of Cincinnati, Cincinnati, OH 45221-0071 (United States); Wang, Yu [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Al-Abed, Souhail R. [National Risk Management Research Laboratory, U.S. Environmental Protection Agency, 26 West Martin Luther King Drive, Cincinnati, OH 45268 (United States); Zhou, Dong-Mei, E-mail: dmzhou@issas.ac.cn [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China)

    2012-08-15

    Highlights: Black-Right-Pointing-Pointer A kinetic model was used to predict the radical species and their distributions. Black-Right-Pointing-Pointer The generated radical species were identified by EPR. Black-Right-Pointing-Pointer The second-order rate constants of sulfate radical with PCBs were determined. - Abstract: Advanced oxidation processes (AOPs) based on sulfate radical (SO{sub 4}{center_dot}{sup -}) have been recently used for soil and groundwater remediation. The presence of chloride ion in natural or wastewater decreases the reactivity of sulfate radical system, but explanations for this behavior were inconsistent, and the mechanisms are poorly understood. Therefore, in this paper we investigated the effect of chloride ion on the degradation of 2,4,4 Prime -CB (PCB28) and biphenyl (BP) by persulfate, based on the produced SO{sub 4}{center_dot}{sup -}. The results showed that the presence of chloride ion greatly inhibited the transformation of PCB28 and BP. Transformation intermediates of BP were monitored, suggesting that the chloride ion can react with SO{sub 4}{center_dot}{sup -} to produce chlorine radical, which reacts with BP to generate chlorinated compounds. To better understand the underlying mechanisms of these processes, a kinetic model was developed for predicting the effect of chloride ion on the types of radical species and their distributions. The results showed that chloride ion could influence the selectivity of radical species and their distribution, and increase the concentration of the sum of radical species. In addition, the second-order rate constants of sulfate radical with PCBs were determined, and quantum-chemical descriptors were introduced to predict the rate constants of other PCBs based on our experimental data.

  2. Riparian spiders as sentinels of polychlorinated biphenyl contamination across heterogeneous aquatic ecosystems.

    Science.gov (United States)

    Kraus, Johanna M; Gibson, Polly P; Walters, David M; Mills, Marc A

    2017-05-01

    Riparian spiders are being used increasingly to track spatial patterns of contaminants in and fluxing from aquatic ecosystems. However, our understanding of the circumstances under which spiders are effective sentinels of aquatic pollution is limited. The present study tests the hypothesis that riparian spiders may be effectively used to track spatial patterns of sediment pollution by polychlorinated biphenyls (PCBs) in aquatic ecosystems with high habitat heterogeneity. The spatial pattern of ΣPCB concentrations in 2 common families of riparian spiders sampled in 2011 to 2013 generally tracked spatial variation in sediment ΣPCBs across all sites within the Manistique River Great Lakes Area of Concern (AOC), a rivermouth ecosystem located on the south shore of the Upper Peninsula, Manistique (MI, USA) that includes harbor, river, backwater, and lake habitats. Sediment ΣPCB concentrations normalized for total organic carbon explained 41% of the variation in lipid-normalized spider ΣPCB concentrations across 11 sites. Furthermore, 2 common riparian spider taxa (Araneidae and Tetragnathidae) were highly correlated (r 2  > 0.78) and had similar mean ΣPCB concentrations when averaged across all years. The results indicate that riparian spiders may be useful sentinels of relative PCB availability to aquatic and riparian food webs in heterogeneous aquatic ecosystems like rivermouths where habitat and contaminant variability may make the use of aquatic taxa less effective. Furthermore, the present approach appears robust to heterogeneity in shoreline development and riparian vegetation that support different families of large web-building spiders. Environ Toxicol Chem 2017;36:1278-1286. Published 2016 Wiley Periodicals, Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America. Published 2016 Wiley Periodicals, Inc. on behalf of SETAC. This article is a US government work and, as such, is in

  3. Chronic treatment with polychlorinated biphenyls (PCB) during pregnancy and lactation in the rat

    International Nuclear Information System (INIS)

    Cocchi, Daniela; Tulipano, Giovanni; Colciago, Alessandra; Sibilia, Valeria; Pagani, Francesca; Vigano, Daniela; Rubino, Tiziana; Parolaro, Daniela; Bonfanti, Patrizia; Colombo, Anita; Celotti, Fabio

    2009-01-01

    Polychlorinated biphenyls (PCBs) are pollutants detected in animal tissues and breast milk. The experiments described in the present paper were aimed at evaluating whether the four PCB congeners most abundant in animal tissues (PCB-138, -153, -180 and -126), administered since fetal life till weaning, can induce long-term alterations of GH-axis activity and bone mass in the adult rat. We measured PCB accumulation in rat brain and liver, somatic growth, pituitary GH expression and plasma hormone concentrations at different ages. Finally, we studied hypothalamic somatostatin expression and bone structure in adulthood, following long-term PCB exposure. Dams were treated during pregnancy from GD15 to GD19 and during breast-feeding. A constant reduction of the growth rate in both male and female offspring from weaning to adulthood was observed in exposed animals. Long-lasting alterations on hypothalamic-pituitary GH axis were indeed observed in PCB-exposed rats in adulthood: increased somatostatin expression in hypothalamic periventricular nucleus (both males and females) and lateral arcuate nucleus (males, only) and decreased GH mRNA levels in the pituitary of male rats. Plasma IGF-1 levels were higher in PCB-exposed male and female animals as compared with controls at weaning and tended to be higher at PN60. Plasma testosterone and thyroid hormone concentrations were not significantly affected by exposure to PCBs. In adulthood, PCBs caused a significant reduction of bone mineral content and cortical bone thickness of tibiae in male rat joint to increased width of the epiphyseal cartilage disk. In conclusion, the developmental exposure to the four selected PCB compounds used in the present study induced far-reaching effects in the adult offspring, the male rats appearing more sensitive than females.

  4. Structural insights into the metabolism of 2-chlorodibenzofuran by an evolved biphenyl dioxygenase

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Pravindra [Department of Biological Sciences and Center for Cancer Research, Purdue University, West Lafayette, IN 47907 (United States); Department of Biotechnology, Indian Institute of Technology, Roorkee 247667 (India); Mohammadi, Mahmood [Institut National de la Recherche Scientifique (INRS-Institut Armand-Frappier), Laval, QC, Canada H7V 1B7 (Canada); Dhindwal, Sonali [Department of Biotechnology, Indian Institute of Technology, Roorkee 247667 (India); Pham, Thi Thanh My [Institut National de la Recherche Scientifique (INRS-Institut Armand-Frappier), Laval, QC, Canada H7V 1B7 (Canada); Bolin, Jeffrey T. [Department of Biological Sciences and Center for Cancer Research, Purdue University, West Lafayette, IN 47907 (United States); Sylvestre, Michel, E-mail: Michel.Sylvestre@iaf.inrs.ca [Institut National de la Recherche Scientifique (INRS-Institut Armand-Frappier), Laval, QC, Canada H7V 1B7 (Canada)

    2012-05-18

    Highlights: Black-Right-Pointing-Pointer Regiospecificity of BphAE{sub RR41} toward dibenzofuran and 2-chlorodibenzofuran differs. Black-Right-Pointing-Pointer We compared the structures of the substrate-bound forms of the enzyme with both substrates. Black-Right-Pointing-Pointer Dibenzofuran is compelled to move during the catalytic reaction. Black-Right-Pointing-Pointer Ser283 contact with 2-chlorodibenzofuran helps prevent substrate movement during the reaction. -- Abstract: The biphenyl dioxygenase of Burkholderia xenovorans LB400 (BphAE{sub LB400}) is a Rieske-type oxygenase that catalyzes the stereospecific oxygenation of many heterocyclic aromatics including dibenzofuran. In a previous work, we evolved BphAE{sub LB400} and obtained BphAE{sub RR41}. This variant metabolizes dibenzofuran and 2-chlorodibenzofuran more efficiently than BphAE{sub LB400}. However, the regiospecificity of BphAE{sub RR41} toward these substrates differs. Dibenzofuran is metabolized principally through a lateral dioxygenation whereas 2-chlorodibenzofuran is metabolized principally through an angular dioxygenation. In order to explain this difference, we examined the crystal structures of both substrate-bound forms of BphAE{sub RR41} obtained under anaerobic conditions. This structure analysis, in combination with biochemical data for a Ser283Gly mutant provided evidences that the substrate is compelled to move after oxygen-binding in BphAE{sub RR41}:dibenzofuran. In BphAE{sub RR41}:2-chlorodibenzofuran, the chlorine atom is close to the side chain of Ser283. This contact is missing in the BphAE{sub RR41}:dibenzofuran, and strong enough in the BphAE{sub RR41}:2-chlorodibenzofuran to help prevent substrate movement during the catalytic reaction.

  5. Structural insights into the metabolism of 2-chlorodibenzofuran by an evolved biphenyl dioxygenase

    International Nuclear Information System (INIS)

    Kumar, Pravindra; Mohammadi, Mahmood; Dhindwal, Sonali; Pham, Thi Thanh My; Bolin, Jeffrey T.; Sylvestre, Michel

    2012-01-01

    Highlights: ► Regiospecificity of BphAE RR41 toward dibenzofuran and 2-chlorodibenzofuran differs. ► We compared the structures of the substrate-bound forms of the enzyme with both substrates. ► Dibenzofuran is compelled to move during the catalytic reaction. ► Ser283 contact with 2-chlorodibenzofuran helps prevent substrate movement during the reaction. -- Abstract: The biphenyl dioxygenase of Burkholderia xenovorans LB400 (BphAE LB400 ) is a Rieske-type oxygenase that catalyzes the stereospecific oxygenation of many heterocyclic aromatics including dibenzofuran. In a previous work, we evolved BphAE LB400 and obtained BphAE RR41 . This variant metabolizes dibenzofuran and 2-chlorodibenzofuran more efficiently than BphAE LB400 . However, the regiospecificity of BphAE RR41 toward these substrates differs. Dibenzofuran is metabolized principally through a lateral dioxygenation whereas 2-chlorodibenzofuran is metabolized principally through an angular dioxygenation. In order to explain this difference, we examined the crystal structures of both substrate-bound forms of BphAE RR41 obtained under anaerobic conditions. This structure analysis, in combination with biochemical data for a Ser283Gly mutant provided evidences that the substrate is compelled to move after oxygen-binding in BphAE RR41 :dibenzofuran. In BphAE RR41 :2-chlorodibenzofuran, the chlorine atom is close to the side chain of Ser283. This contact is missing in the BphAE RR41 :dibenzofuran, and strong enough in the BphAE RR41 :2-chlorodibenzofuran to help prevent substrate movement during the catalytic reaction.

  6. Determination of plasma concentrations of organochlorine pesticides and polychlorinated biphenyls in pet cats and dogs.

    Science.gov (United States)

    Yavuz, Oguzhan; Arslan, Handan Hilal; Esin, Cagatay; Das, Yavuz Kursad; Aksoy, Abdurrahman

    2018-01-01

    The aim of this study was the determination of plasma concentrations of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in cats and dogs and evaluation of their prevalence and possible effects. The concentrations of nine OCPs, such as α-hexachlorocyclohexane (HCH), β-HCH, γ-HCH, hexachlorobenzene (HCB), aldrin, 2,4'-dichlorodiphenyltrichloroethane (2,4'-DDT), 4,4'-DDT, 2,4'-dichlorodiphenyldichloroethylene (2,4'-DDE) and 4,4'-DDE and 16 PCBs (PCB-28, -52, -70, -74, -81, -99, -101, -118, -138, -153, -156, -170, -180, -183, -187 and -208) were evaluated in the plasma samples of pet cats ( n = 15) and dogs ( n = 21). The concentrations of OCPs ranged from 1.12 ng g -1 lipid weight (lw) to 7.65 ng g -1 lw in cats and from 1.25 ng g -1 lw to 6.79 ng g -1 lw in dogs. In addition, mean PCB levels were 0.58-5.66 and 0.52-6.62 ng g -1 lw in cats and dogs, respectively. β-HCH, γ-HCH and PCB-138 levels were significantly higher in dogs ( p < 0.05). As far as could be determined, OCPs and PCBs were detected in the plasma samples of domestic cats and dogs in Turkey for the first time. Their concentrations were similar to those reported in earlier studies abroad. However, in contrast to other research, the levels of some OCPs were higher in dogs than in cats. It is concluded that, because of their high prevalence and potential health effects in animals and humans, OCP and PCB levels should be monitored systematically in domestic cats and dogs.

  7. NUMERICAL MODELING OF THE FIELDS OF POLYCHLORINATED BIPHENYLS IN THE BLACK SEA

    Directory of Open Access Journals (Sweden)

    Vitaly Ivanov

    2013-01-01

    Full Text Available A mathematical three-dimensional model was developed by combining a physically complete block of circulation with modules of transport and transformation of detritus and polychlorinated biphenyls (PCBs. This z-coordinate model has a horizontal resolution of 5 × 5 km, 45 vertical levels, and a step of 5 minutes. The model considers gravitational sedimentation and decomposition of detritus, as well as its deposition and erosion on the bottom. To calculate the transport and transformation of PCBs in the Sea, the model uses three state variables: the concentration of PCBs in solution, in detritus, and in the upper layer of sediment. It also considers sorption, desorption, and reversible flows of PCBs at the bottom.A 20-day model calculation was performed to simulate a potential accidental release of PCBs in the area of the Danube Delta in spring. The PCBs advection flows dominated and were comparable to the adsorption/desorption flows, while the diffusion fluxes were infinitesimal. Up to 20% of discharged PCBs were adsorbed by detritus in the first two days after the accident. There was a gradual accumulation of PCBs on the bottom; 16 days after the accident, 18% of the PCBs were bound to the sediments. The PCBs transport on detritus serves as a natural buffer mechanism that weakens the spread of PCBs in the sea. The paper analyzes the dynamics of PCB fields formed as a result of the application of an artificial active sorbent to minimize adverse effects on the ecosystem. An end-user oriented software application was developed; it allows forecasting the dynamics of potential releases of PCBs and planning counter-measures. A user-friendly interface allows tracking the field, visualizing the distribution of PCBs in the water column and sediments, and displaying the balance between dissolved and suspended phases.Key words: multidisciplinary model, PCB transport, adsorption, desorption, sediments

  8. Probabilistic mixture-based image modelling

    Czech Academy of Sciences Publication Activity Database

    Haindl, Michal; Havlíček, Vojtěch; Grim, Jiří

    2011-01-01

    Roč. 47, č. 3 (2011), s. 482-500 ISSN 0023-5954 R&D Projects: GA MŠk 1M0572; GA ČR GA102/08/0593 Grant - others:CESNET(CZ) 387/2010; GA MŠk(CZ) 2C06019; GA ČR(CZ) GA103/11/0335 Institutional research plan: CEZ:AV0Z10750506 Keywords : BTF texture modelling * discrete distribution mixtures * Bernoulli mixture * Gaussian mixture * multi-spectral texture modelling Subject RIV: BD - Theory of Information Impact factor: 0.454, year: 2011 http://library.utia.cas.cz/separaty/2011/RO/haindl-0360244.pdf

  9. Adsorption on mixtures of ion exchangers

    International Nuclear Information System (INIS)

    Triolo, R.; Lietzke, M.H.

    1979-01-01

    A theoretical study has been made of adsorption on mixtures of ion exchangers. The effect of variables such as the concentration of the ion being adsorbed, the concentration of the supporting electrolyte, loading, the values of the capacities and equilibrium constants for the various exchange processes, and the fraction of each adsorber in the mixture on the observed distribution coefficient has been investigated. A computer program has been written to facilitate the calculation of distribution coefficients for the adsorption of an ion on a given mixture of ion exchangers under a specified set of conditions

  10. Principles and practice of mixtures toxicology

    National Research Council Canada - National Science Library

    Mumtaz, Moiz

    2010-01-01

    ... accurate predictions for the adverse effects of mixtures has been limited by the difficulty of acquiring data for all the possible combinations of dose and time that exist even in simple mixtures. Such predictions are also compromised by our use of single-agent toxicity studies since most "realworld" exposures are to mixtures. This has resulted in a variety of approaches (models, protocols, techniques, etc.) to address these issues. These are described in detail in the two dozen chapters of this book along with ca...

  11. Temporal and spatial variation of polychlorinated biphenyls (PCBs) contamination in environmental compartments of highly polluted area in Central Russia.

    Science.gov (United States)

    Malina, Natalia; Mazlova, Elena A

    2017-10-01

    This study highlights the fact that serious contamination from polychlorinated biphenyls (PCBs) still exists in Serpukhov City (Russia). The research help to determine the temporal (16- and 24-year periods) and spatial PCBs distribution in the environmental compartments of the studied region. Samples of soil, sediments, water and plants were analysed in order to establish their contamination levels. The most recent data on the Serpukhov City's soil contamination showed that the PCBs concentrations varies from 0.0009 to 1169 mg/kg depending on the sampling point and the distance from the pollution source. The temporal trends of the contamination distribution with the soil depth showed contamination migration in the upper soil layers of the highly polluted site. The high level of water pollution (11.5 μg/L) in the proximity to the contamination source and the sediments contamination (0.098-119 mg/kg) were determined, as well as the water migration pathways of the PCBs that were prevalent in the studied region. The PCB congener group (by the level of chlorination) analysis showed that heptachlorinated biphenyls were only found in the soils in close proximity to the contamination place, while biphenyls with Cl ≤ 6 were found in the soil samples downstream of the condenser plant and with Cl ≤ 5 in the soil samples upstream of the plant. The plant uptake of PCBs, even on the extremely contaminated site, was shown. In turn, this research present new knowledge necessary for the development of a contaminated territory remediation strategy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Dual Two-Component Regulatory Systems Are Involved in Aromatic Compound Degradation in a Polychlorinated-Biphenyl Degrader, Rhodococcus jostii RHA1 ▿ †

    OpenAIRE

    Takeda, Hisashi; Shimodaira, Jun; Yukawa, Kiyoshi; Hara, Naho; Kasai, Daisuke; Miyauchi, Keisuke; Masai, Eiji; Fukuda, Masao

    2010-01-01

    A Gram-positive polychlorinated-biphenyl (PCB) degrader, Rhodococcus jostii RHA1, degrades PCBs by cometabolism with biphenyl. A two-component BphS1T1 system encoded by bphS1 and bphT1 (formerly bphS and bphT) is responsible for the transcription induction of the five gene clusters, bphAaAbAcAdC1B1, etbAa1Ab1CbphD1, etbAa2Ab2AcD2, etbAdbphB2, and etbD1, which constitute multiple enzyme systems for biphenyl/PCB degradation. The bphS2 and bphT2 genes, which encode BphS2 and BphT2, virtually ide...

  13. Studies on air and water pollution. I. Polychlorinated biphenyls and benzopyrene status report July 1977 - June 1978

    International Nuclear Information System (INIS)

    Santos, F.L.; Cunanan, S.A.

    1979-01-01

    An analytical methodology developed for trace amounts of polychlorinated biphenyls (PCB's) in water was described. The water sample was extracted with hexane and the extract passes through a florisil column. The cleaned extract was concentrated and then analyzed by gas chromatography using an electron capture detector. The methodology has an efficiency of 85% recovery for PCB spiked at a concentration level of 1 ppm. Minimum detection limit obtained was 0.5 ppm PCB in water. A total of 27 water samples were collected and analyzed during the period January - June 1978. No PCB's were detected in the samples. (author)

  14. Use of RIA determination of polychlorinated biphenyls (PCB) in prevention of their penetration into the food chain

    International Nuclear Information System (INIS)

    Zajic, J.; Sisak, M.; Diblikova, I.; Bendova, J.; Matouskova, O.; Hruska, K.

    1991-01-01

    Radiomimmunological determination of polychlorinated biphenyls in milk can serve in the screening of milk cows and condemnation of contaminated individuals. The source of PCB contamination can be ascertained by checking the routes the milk is passing. The RIA method was also employed to examine bioptically taken cow fat. The method was also applied to human milk in a maternity hospital in Brno; out of 55 samples, none exhibited a PCB concentration higher than 1.4 mg/kg. (M.D.). 3 tabs., 4 figs

  15. Comparison of solvent extraction and solid-phase extraction for the determination of polychlorinated biphenyls in transformer oil.

    Science.gov (United States)

    Mahindrakar, A N; Chandra, S; Shinde, L P

    2014-01-01

    Solid-phase extraction (SPE) of nine polychlorinated biphenyls (PCBs) from transformer oil samples was evaluated using octadecyl (CI8)-bonded porous silica. The efficiency of SPE of these PCBs was compared with those obtained by solvent extraction with DMSO and hexane. Average recoveries exceeding 95% for these PCBs were obtained via the SPE method using small cartridges containing 100mg of 40 pm CI8-bonded porous silica. The average recovery by solvent extraction with DMSO and hexane exceeded 83%. It was concluded that the recoveries and precision for the solvent extraction of PCBs were poorer than those for the SPE. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. OXIDATION OF POLYCHLORINATED BIPHENYLS BY LIVER TISSUE SLICES FROM PHENOBARBITAL-PRETREATED MICE IS CONGENER-SPECIFIC AND ATROPSELECTIVE

    OpenAIRE

    Wu, Xianai; Duffel, Michael; Lehmler, Hans-Joachim

    2013-01-01

    Mouse models are powerful tools to study the developmental neurotoxicity of polychlorinated biphenyls (PCBs); however, studies of the oxidation of chiral PCB congeners to potentially neurotoxic hydroxylated metabolites (OH-PCBs) in mice have not been reported. Here we investigate the atropselective oxidation of chiral PCB 91 (2,2',3,4',6-pentachlorobiphenyl), PCB 95 (2,2',3,5',6-pentachlorobiphenyl), PCB 132 (2,2',3,3',4,6'-hexachlorobiphenyl), PCB 136 (2,2',3,3',6,6'-hexachlorobiphenyl) and ...

  17. The concentrations of radionuclides, heavy metals, and poloychlorinated biphenyls in field mice collected from regional background areas. Revision 3

    Energy Technology Data Exchange (ETDEWEB)

    Fresquez, Philip R. [Los Alamos National Laboratory

    2016-01-21

    Field mice are effective indicators of contaminant presence. This paper reports the concentrations of various radionuclides, heavy metals, polychlorinated biphenyls, high explosives, perchlorate, and dioxin/furans in field mice (mostly deer mice) collected from regional background areas in northern New Mexico. These data, represented as the regional statistical reference level (the mean plus three standard deviations = 99% confidence level), are used to compare with data from field mice collected from areas potentially impacted by Laboratory operations, as per the Environmental Surveillance Program at Los Alamos National Laboratory.

  18. Quantiles for Finite Mixtures of Normal Distributions

    Science.gov (United States)

    Rahman, Mezbahur; Rahman, Rumanur; Pearson, Larry M.

    2006-01-01

    Quantiles for finite mixtures of normal distributions are computed. The difference between a linear combination of independent normal random variables and a linear combination of independent normal densities is emphasized. (Contains 3 tables and 1 figure.)

  19. Shear-induced phase changes in mixtures

    International Nuclear Information System (INIS)

    Romig, K.D.; Hanley, H.J.M.

    1986-01-01

    A thermodynamic theory to account for the behavior of liquid mixtures exposed to a shear is developed. One consequence of the theory is that shear-induced phase changes are predicted. The theory is based on a thermodynamics that includes specifically the shear rate in the formalism and is applied to mixtures by a straightforward modification of the corresponding states, conformalsolution approach. The approach is general but is used here for a mixture of Lennard-Jones particles with a Lennard-Jones equation of state as a reference fluid. The results are discussed in the context of the Scott and Van Konynenberg phase classification. It is shown that the influence of a shear does affect substantially the type of the phase behavior. Results from the model mixture are equated loosely with those from real polymeric liquids

  20. A simple approach to polymer mixture miscibility.

    Science.gov (United States)

    Higgins, Julia S; Lipson, Jane E G; White, Ronald P

    2010-03-13

    Polymeric mixtures are important materials, but the control and understanding of mixing behaviour poses problems. The original Flory-Huggins theoretical approach, using a lattice model to compute the statistical thermodynamics, provides the basic understanding of the thermodynamic processes involved but is deficient in describing most real systems, and has little or no predictive capability. We have developed an approach using a lattice integral equation theory, and in this paper we demonstrate that this not only describes well the literature data on polymer mixtures but allows new insights into the behaviour of polymers and their mixtures. The characteristic parameters obtained by fitting the data have been successfully shown to be transferable from one dataset to another, to be able to correctly predict behaviour outside the experimental range of the original data and to allow meaningful comparisons to be made between different polymer mixtures.

  1. Model structure selection in convolutive mixtures

    DEFF Research Database (Denmark)

    Dyrholm, Mads; Makeig, S.; Hansen, Lars Kai

    2006-01-01

    The CICAAR algorithm (convolutive independent component analysis with an auto-regressive inverse model) allows separation of white (i.i.d) source signals from convolutive mixtures. We introduce a source color model as a simple extension to the CICAAR which allows for a more parsimonious represent......The CICAAR algorithm (convolutive independent component analysis with an auto-regressive inverse model) allows separation of white (i.i.d) source signals from convolutive mixtures. We introduce a source color model as a simple extension to the CICAAR which allows for a more parsimonious...... representation in many practical mixtures. The new filter-CICAAR allows Bayesian model selection and can help answer questions like: ’Are we actually dealing with a convolutive mixture?’. We try to answer this question for EEG data....

  2. Modelling of an homogeneous equilibrium mixture model

    International Nuclear Information System (INIS)

    Bernard-Champmartin, A.; Poujade, O.; Mathiaud, J.; Mathiaud, J.; Ghidaglia, J.M.

    2014-01-01

    We present here a model for two phase flows which is simpler than the 6-equations models (with two densities, two velocities, two temperatures) but more accurate than the standard mixture models with 4 equations (with two densities, one velocity and one temperature). We are interested in the case when the two-phases have been interacting long enough for the drag force to be small but still not negligible. The so-called Homogeneous Equilibrium Mixture Model (HEM) that we present is dealing with both mixture and relative quantities, allowing in particular to follow both a mixture velocity and a relative velocity. This relative velocity is not tracked by a conservation law but by a closure law (drift relation), whose expression is related to the drag force terms of the two-phase flow. After the derivation of the model, a stability analysis and numerical experiments are presented. (authors)

  3. Viscosities of corium-concrete mixtures

    International Nuclear Information System (INIS)

    Seiler, J.M.; Ganzhorn, J.

    1997-01-01

    Severe accidents on nuclear reactors involve many situations such as pools of molten core material, melt spreading, melt/concrete interactions, etc. The word 'corium' designates mixtures of materials issued from the molten core at high temperature; these mixtures involve mainly: UO2, ZrO2, Zr and, in small amounts, Ni, Cr, Ag, In, Cd. These materials, when flowing out of the reactor vessel, may interact with the concrete of the reactor building thus introducing decomposition products of concrete into the original mixture. These decomposition products are mainly: SiO 2 , FeO, MgO, CaO and Al 2 O 3 in different amounts depending on the nature of the concrete being considered. Siliceous concrete is rich in SiO 2 , limestone concrete contains both SiO 2 and CaO. Liquidus temperatures of such mixtures are generally obove 2300 K whereas solidus temperatures are ∝1400 K. (orig.)

  4. Negative muon capture in noble gas mixtures

    International Nuclear Information System (INIS)

    Hutson, R.L.; Knight, J.D.; Leon, M.; Schillaci, M.E.; Knowles, H.B.; Reidy, J.J.

    1980-01-01

    We have determined the probabilities of atomic negative muon capture in binary mixtures of the gases He, Ne, Ar, and Kr at partial pressures near five atmospheres. Relative capture rates were deduced from measured muonic X-ray yields. (orig.)

  5. Mixture design procedure for flexible base.

    Science.gov (United States)

    2013-04-01

    This document provides information on mixture design requirements for a flexible base course. Sections : design requirements, job mix formula, contractor's responsibility, and engineer's responsibility. Tables : material requirements; requirements fo...

  6. Predicting skin permeability from complex chemical mixtures

    International Nuclear Information System (INIS)

    Riviere, Jim E.; Brooks, James D.

    2005-01-01

    Occupational and environmental exposure to topical chemicals is usually in the form of complex chemical mixtures, yet risk assessment is based on experimentally derived data from individual chemical exposures from a single, usually aqueous vehicle, or from computed physiochemical properties. We present an approach using hybrid quantitative structure permeation relationships (QSPeR) models where absorption through porcine skin flow-through diffusion cells is well predicted using a QSPeR model describing the individual penetrants, coupled with a mixture factor (MF) that accounts for physicochemical properties of the vehicle/mixture components. The baseline equation is log k p = c + mMF + aΣα 2 H + bΣβ 2 H + sπ 2 H + rR 2 + vV x where Σα 2 H is the hydrogen-bond donor acidity, Σβ 2 H is the hydrogen-bond acceptor basicity, π 2 H is the dipolarity/polarizability, R 2 represents the excess molar refractivity, and V x is the McGowan volume of the penetrants of interest; c, m, a, b, s, r, and v are strength coefficients coupling these descriptors to skin permeability (k p ) of 12 penetrants (atrazine, chlorpyrifos, ethylparathion, fenthion, methylparathion, nonylphenol, ρ-nitrophenol, pentachlorophenol, phenol, propazine, simazine, and triazine) in 24 mixtures. Mixtures consisted of full factorial combinations of vehicles (water, ethanol, propylene glycol) and additives (sodium lauryl sulfate, methyl nicotinate). An additional set of 4 penetrants (DEET, SDS, permethrin, ricinoleic acid) in different mixtures were included to assess applicability of this approach. This resulted in a dataset of 16 compounds administered in 344 treatment combinations. Across all exposures with no MF, R 2 for absorption was 0.62. With the MF, correlations increased up to 0.78. Parameters correlated to the MF include refractive index, polarizability and log (1/Henry's Law Constant) of the mixture components. These factors should not be considered final as the focus of these studies

  7. On modeling of structured multiphase mixtures

    International Nuclear Information System (INIS)

    Dobran, F.

    1987-01-01

    The usual modeling of multiphase mixtures involves a set of conservation and balance equations of mass, momentum, energy and entropy (the basic set) constructed by an averaging procedure or postulated. The averaged models are constructed by averaging, over space or time segments, the local macroscopic field equations of each phase, whereas the postulated models are usually motivated by the single phase multicomponent mixture models. In both situations, the resulting equations yield superimposed continua models and are closed by the constitutive equations which place restrictions on the possible material response during the motion and phase change. In modeling the structured multiphase mixtures, the modeling of intrinsic motion of grains or particles is accomplished by adjoining to the basic set of field equations the additional balance equations, thereby placing restrictions on the motion of phases only within the imposed extrinsic and intrinsic sources. The use of the additional balance equations has been primarily advocated in the postulatory theories of multiphase mixtures and are usually derived through very special assumptions of the material deformation. Nevertheless, the resulting mixture models can predict a wide variety of complex phenomena such as the Mohr-Coulomb yield criterion in granular media, Rayleigh bubble equation, wave dispersion and dilatancy. Fundamental to the construction of structured models of multiphase mixtures are the problems pertaining to the existence and number of additional balance equations to model the structural characteristics of a mixture. Utilizing a volume averaging procedure it is possible not only to derive the basic set of field equation discussed above, but also a very general set of additional balance equations for modeling of structural properties of the mixture

  8. Muonium radicals in benzene-styrene mixtures

    International Nuclear Information System (INIS)

    Ng, B.W.; Stadlbauer, J.W.; Walker, D.C.

    1984-01-01

    Muonium radicals were observed through their μ + SR precession frequencies in high transverse magnetic fields in pure benzene, pure styrene and their mixtures, all as liquids at room temperature. In benzene-styrene mixtures, the radicals obtained in each pure liquid are both present, so no slow (10 -9 -10 -5 s) intermolecular exchange occurs; but strong selectivity was found with the formation of the radical from styrene being about eight-times more probable than the radical from benzene. (Auth.)

  9. Isotope mixtures of hydrogen in vanadium

    International Nuclear Information System (INIS)

    Mecking-Schloetensack, P.

    1982-03-01

    The properties of isotope-mixtures of Protium and Deuterium stored in Vanadium have been studied. Protium and Deuterium are existing as interstitial-atoms on tetrahedral sites as well as on octahedral sites in this system. This feature leads to large isotopic-effects between the two isotopes. The dependence of the thermodynamic functions like heat of solution, nonconfigurational entropy, specific heat and ordering temperatures from the composition of the isotope-mixture has been determined. (orig.)

  10. Thermodiffusion in multicomponent n-alkane mixtures.

    Science.gov (United States)

    Galliero, Guillaume; Bataller, Henri; Bazile, Jean-Patrick; Diaz, Joseph; Croccolo, Fabrizio; Hoang, Hai; Vermorel, Romain; Artola, Pierre-Arnaud; Rousseau, Bernard; Vesovic, Velisa; Bou-Ali, M Mounir; Ortiz de Zárate, José M; Xu, Shenghua; Zhang, Ke; Montel, François; Verga, Antonio; Minster, Olivier

    2017-01-01

    Compositional grading within a mixture has a strong impact on the evaluation of the pre-exploitation distribution of hydrocarbons in underground layers and sediments. Thermodiffusion, which leads to a partial diffusive separation of species in a mixture due to the geothermal gradient, is thought to play an important role in determining the distribution of species in a reservoir. However, despite recent progress, thermodiffusion is still difficult to measure and model in multicomponent mixtures. In this work, we report on experimental investigations of the thermodiffusion of multicomponent n -alkane mixtures at pressure above 30 MPa. The experiments have been conducted in space onboard the Shi Jian 10 spacecraft so as to isolate the studied phenomena from convection. For the two exploitable cells, containing a ternary liquid mixture and a condensate gas, measurements have shown that the lightest and heaviest species had a tendency to migrate, relatively to the rest of the species, to the hot and cold region, respectively. These trends have been confirmed by molecular dynamics simulations. The measured condensate gas data have been used to quantify the influence of thermodiffusion on the initial fluid distribution of an idealised one dimension reservoir. The results obtained indicate that thermodiffusion tends to noticeably counteract the influence of gravitational segregation on the vertical distribution of species, which could result in an unstable fluid column. This confirms that, in oil and gas reservoirs, the availability of thermodiffusion data for multicomponent mixtures is crucial for a correct evaluation of the initial state fluid distribution.

  11. Using Big Data Analytics to Address Mixtures Exposure

    Science.gov (United States)

    The assessment of chemical mixtures is a complex issue for regulators and health scientists. We propose that assessing chemical co-occurrence patterns and prevalence rates is a relatively simple yet powerful approach in characterizing environmental mixtures and mixtures exposure...

  12. A turbulence model in mixtures. First part: Statistical description of mixture

    International Nuclear Information System (INIS)

    Besnard, D.

    1987-03-01

    Classical theory of mixtures gives a model for molecular mixtures. This kind of model is based on a small gradient approximation for concentration, temperature, and pression. We present here a mixture model, allowing for large gradients in the flow. We also show that, with a local balance assumption between material diffusion and flow gradients evolution, we obtain a model similar to those mentioned above [fr

  13. Measurement and estimated health risks of volatile organic compounds and polychlorinated biphenyls in air at the Hanford Site

    International Nuclear Information System (INIS)

    Patton, G.W.; Cooper, A.T.; Blanton, M.L.

    1994-10-01

    A variety of radioactive and nonradioactive chemicals have been released in effluent streams and discharged to waste disposal facilities during the nuclear materials production period at the Hanford Site. Extensive environmental surveillance for radioactive materials has occurred at Hanford; however, only limited information is available on the types and concentrations of organic pollutants potentially present. This report describes work performed to provide the Hanford Site Surface Environmental Surveillance Project with representative air concentration data for volatile organic compounds and polychlorinated biphenyls (PCBs). US Environmental Protection Agency (USEPA) volatile organic compound sampling methods evaluated for Hanford Site use were carbon-based adsorbent traps (TO-2) and Summa air canisters (TO-14). Polychlorinated biphenyls were sampled using USEPA method (TO-4), which uses glass fiber filters and polyurethane foam adsorbent beds to collect the PCBS. This report also presents results for environmental surveillance samples collected for volatile organic compound and PCB analyses from 1990 to 1993. All measured air concentrations of volatile organic compounds and PCBs were well below applicable maximum allowable concentration standards for air contaminants. Because of the lack of ambient air concentration standards, a conservative estimate is provided of the potential human health impacts from exposure to the ambient air concentrations measured on the Hanford Site

  14. Polychlorinated biphenyls and biotransformation enzymes in three species of sea turtles from the Baja California peninsula of Mexico.

    Science.gov (United States)

    Richardson, K L; Lopez Castro, M; Gardner, S C; Schlenk, D

    2010-01-01

    Concentrations of polychlorinated biphenyls (PCBs) as well as the expression patterns of cytochrome P450 (CYP) enzymes and glutathione-S-transferase (GST) activities were measured in livers of loggerhead (Caretta caretta), green (Chelonia mydas), and olive ridley (Lepidocheyls olivacea) sea turtles from the Baja California peninsula of Mexico. The mean concentrations of total PCBs were 18.1, 10.5, and 15.2 ng/g wet weight (ww) respectively for the three species and PCB 153 was the dominant congener in all samples. Total PCB concentrations were dominated by penta- and hexa-chlorinated biphenyls. The mean estimated TEQs were 42.8, 22.9, and 10.4 pg/g (ww) for loggerhead, green, and olive ridley, respectively, and more than 70% was accounted for by non-ortho PCBs. Western blots revealed the presence of hepatic microsomal proteins that cross-reacted with anti-CYP2K1 and anti-CYP3A27 antibodies but not with anti-CYP1A antibody. There were no significant differences in GST activities between species. Grouping congeners based on structure-activity relationships for CYP isoenzymes suggested limited activity of CYP1A contribution to PCB biotransformation in sea turtles. These results suggest potential accumulation of PCBs that are CYP1A substrates and provide evidence for biotransformation capacity, which differs from known animal models, highlighting the need for further studies in reptiles, particularly those threatened with extinction.

  15. Selective scanning tunnelling microscope electron-induced reactions of single biphenyl molecules on a Si(100) surface.

    Science.gov (United States)

    Riedel, Damien; Bocquet, Marie-Laure; Lesnard, Hervé; Lastapis, Mathieu; Lorente, Nicolas; Sonnet, Philippe; Dujardin, Gérald

    2009-06-03

    Selective electron-induced reactions of individual biphenyl molecules adsorbed in their weakly chemisorbed configuration on a Si(100) surface are investigated by using the tip of a low-temperature (5 K) scanning tunnelling microscope (STM) as an atomic size source of electrons. Selected types of molecular reactions are produced, depending on the polarity of the surface voltage during STM excitation. At negative surface voltages, the biphenyl molecule diffuses across the surface in its weakly chemisorbed configuration. At positive surface voltages, different types of molecular reactions are activated, which involve the change of adsorption configuration from the weakly chemisorbed to the strongly chemisorbed bistable and quadristable configurations. Calculated reaction pathways of the molecular reactions on the silicon surface, using the nudge elastic band method, provide evidence that the observed selectivity as a function of the surface voltage polarity cannot be ascribed to different activation energies. These results, together with the measured threshold surface voltages and the calculated molecular electronic structures via density functional theory, suggest that the electron-induced molecular reactions are driven by selective electron detachment (oxidation) or attachment (reduction) processes.

  16. Distribution of polychlorinated biphenyls, phthalic acid esters, polycyclic aromatic hydrocarbons and organochlorine substances in the Moscow River, Russia

    International Nuclear Information System (INIS)

    Eremina, Natalia; Paschke, Albrecht; Mazlova, Elena A.; Schüürmann, Gerrit

    2016-01-01

    The purpose of this study was to investigate the levels of polychlorinated biphenyl (PCB), phthalic acid esters (PAE), polycyclic aromatic hydrocarbons (PAH) and organochlorine substances (OCP) in the Moscow River water. Some studies have reported the occurrence of these substances in the soil of the Moscow region; however, no study has yet established an overview for these compounds in the Moscow River water. In this study the Moscow River water contamination with PAEs, PAHs and OCPs was determined. Obtained results were associated with the resident area located on the river bank, and the possible contamination sources were considered. The obtained data were compared with the data on the contamination of the different world-wide rivers. This research indicates the further study necessity of the Moscow region to cover more contaminated sites and environmental compartments. - Highlights: • The monitoring system creation of the Moscow River is necessary. • The wastewater plant is the source of the river contamination with triclosan. • The Moscow River is contaminated with the low chlorinated biphenyls. • There is a background contamination of the Moscow River with phthalates. - The organic pollutants contamination levels of the Moscow River were investigated.

  17. Cucurbita spp. and Cucumis sativus enhance the dissipation of polychlorinated biphenyl congeners by stimulating soil microbial community development

    International Nuclear Information System (INIS)

    Qin, Hua; Brookes, Philip C.; Xu, Jianming

    2014-01-01

    A number of Cucurbita species have the potential to extract polychlorinated biphenyls (PCBs) from soil, but their impact on the soil microbial communities responsible for PCB degradation remains unclear. A greenhouse experiment was conducted to investigate the effect of three Cucurbita and one Cucumis species on PCB dissipation and soil microbial community structure. Compared to the unplanted control, enhanced losses of PCBs (19.5%–42.7%) were observed in all planted soils. Cucurbita pepo and Cucurbita moschata treatments were more efficient in PCB dissipation, and have similar patterns of soil phospholipid fatty acids (PLFAs) and PCB congener profiles. Cucurbita treatments tend to have higher soil microbial biomass than Cucumis. Gram-negative (G − ) bacteria were significantly correlated with PCB degradation rates (R 2 = 0.719, p − bacteria were correlated with dissipation of the penta homologue group (R 2 = 0.590, p − bacteria contributed significantly to soil PCB dissipation. • Fungi have a great potential in the dissipation of high chlorinated biphenyls. -- Cucurbita associated fungi and G − bacteria have important influence on soil PCB dissipation rate and congener profile

  18. Ultrasound-accelerated synthesis of biphenyl compounds using novel Pd(0) nanoparticles immobilized on bio-composite.

    Science.gov (United States)

    Baran, Talat

    2018-07-01

    This study describes (i) an eco-friendly approach for design of Pd(0) nanoparticles on a natural composite, which is composed of carboxymethyl cellulose/agar polysaccharides (CMC/AG), without using any toxic reducing agents and (ii) development of ultrasound assisted simple protocol for synthesis of biphenyl compounds. Chemical characterization studies of Pd(0) nanoparticles (Pd NPs@CMC/AG) revealed that size of the particles were in the range of 37-55 nm. Catalytic performance of Pd NPs@CMC/AG was evaluated in synthesis of various biphenyl compounds by using the ultrasound-assisted method that was developed in this study. Pd NPs@CMC/AG exhibited excellent catalytic performance by producing high reaction yields. In addition, Pd NPs@CMC/AG was successfully used up to six reaction cycles without losing its catalytic activity, indicating high reproducibility of Pd NPs@CMC/AG. Additionally, compared to conventional the methods, new ultrasound-assisted synthesis technique that was followed in this study exhibited some advantages such as shorter reaction time, greener reaction conditions, higher yields and easier work-up. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. Antifungal activity of schinol and a new biphenyl compound isolated from Schinus terebinthifolius against the pathogenic fungus Paracoccidioides brasiliensis.

    Science.gov (United States)

    Johann, Susana; Sá, Nívea P; Lima, Luciana A R S; Cisalpino, Patricia S; Cota, Betania B; Alves, Tânia M A; Siqueira, Ezequias P; Zani, Carlos L

    2010-10-12

    The aim of this study was to isolate and identify the antifungal compounds from the extracts of Schinus terebinthifolius (Anacardiaceae) against clinical isolates of the pathogenic fungus Paracoccidioides brasiliensis. The hexane and dichlomethane fractions from leaves and stems of S. terebinthifolius were fractionated using several chromatography techniques to afford four compounds. The compounds isolated from S. terebinthifolius were identified as schinol (1), a new biphenyl compound, namely, 4'-ethyl-4-methyl-2,2',6,6'-tetrahydroxy[1,1'-biphenyl]-4,4'-dicarboxylate (2), quercetin (3), and kaempferol (4). Compounds 1 and 2 were active against different strains of P. brasiliensis, showing a minimal inhibitory concentration value against the isolate Pb B339 of 15.6 μg/ml. The isolate Pb 1578 was more sensitive to compound 1 with a MIC value of 7.5 μg/ml. Schinol presented synergistic effect only when combined with itraconazole. The compounds isolated from S. terebinthifolius were not able to inhibit cell wall synthesis or assembly using the sorbitol assay. This work reveals for the first time the occurrence of compound 2 and discloses activity of compounds 1 and 2 against several clinical isolates of P. brasiliensis. These results justify further studies to clarify the mechanisms of action of these compounds.

  20. Corrective Action Investigation Plan for Corrective Action Unit 528: Polychlorinated Biphenyls Contamination, Nevada Test Site, Nevada, Rev. 0

    Energy Technology Data Exchange (ETDEWEB)

    U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office

    2003-05-08

    This Corrective Action Investigation Plan contains the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office's approach to collect the data necessary to evaluate corrective action alternatives appropriate for the closure of Corrective Action Unit (CAU) 528, Polychlorinated Biphenyls Contamination (PCBs), Nevada Test Site (NTS), Nevada, under the Federal Facility Agreement and Consent Order. Located in the southwestern portion of Area 25 on the NTS in Jackass Flats (adjacent to Test Cell C [TCC]), CAU 528 consists of Corrective Action Site 25-27-03, Polychlorinated Biphenyls Surface Contamination. Test Cell C was built to support the Nuclear Rocket Development Station (operational between 1959 and 1973) activities including conducting ground tests and static firings of nuclear engine reactors. Although CAU 528 was not considered as a direct potential source of PCBs and petroleum contamination, two potential sources of contamination have nevertheless been identified from an unknown source in concentrations that could potentially pose an unacceptable risk to human health and/or the environment. This CAU's close proximity to TCC prompted Shaw to collect surface soil samples, which have indicated the presence of PCBs extending throughout the area to the north, east, south, and even to the edge of the western boundary. Based on this information, more extensive field investigation activities are being planned, the results of which are to be used to support a defensible evaluation of corrective action alternatives in the corrective action decision document.