Science.gov

Sample records for coal tar allergy

  1. Coal liquefaction with coal tar solvent

    SciTech Connect

    Gir, S.; Rhodes, D.E.

    1986-12-16

    A method is described of liquefying coal, comprising: mixing solid coal with a process solvent comprising coal tar material which has been at least partially hydrogenated under conditions which selectively hydrogenate aromatic coal tar components to hydroaromatics and which preserve the integrity of organonitrogen coal tar components, to produce a coal-solvent slurry; treating the coal-solvent slurry under coal-liquefying conditions in a liquefaction zone to produce a solution containing coal liquefaction products; and recovering coal liquefaction products from the solution.

  2. Centrifuge treatment of coal tar

    SciTech Connect

    L.A. Kazak; V.Z. Kaidalov; L.F. Syrova; O.S. Miroshnichenko; A.S. Minakov

    2009-07-15

    New technology is required for the removal of water and heavy fractions from regular coal tar. Centrifuges offer the best option. Purification of coal tar by means of centrifuges at OAO NLMK permits the production of pitch coke or electrode pitch that complies with current standards.

  3. Coal tar phototherapy for psoriasis reevaluated: erythemogenic versus suberythemogenic ultraviolet with a tar extract in oil and crude coal tar

    SciTech Connect

    Lowe, N.J.; Wortzman, M.S.; Breeding, J.; Koudsi, H.; Taylor, L.

    1983-06-01

    Recent studies have questioned the therapeutic value of coal tar versus ultraviolet (UV) radiation and their relative necessity in phototherapy for psoriasis. In this investigation, different aspects of tar phototherapy have been studied in single-blind bilateral paired comparison studies. The effects of 1% crude coal tar were compared with those of petrolatum in conjunction with erythemogenic and suberythemogenic doses of ultraviolet light (UVB) using a FS72 sunlamp tubed cabinet. Crude coal tar was clinically superior to petrolatum with suberythemogenic ultraviolet. With the erythemogenic UVB, petrolatum was equal in efficacy to crude coal tar. Suberythemogenic UVB was also used adjunctively to compare the effects of a 5% concentration of a tar extract in an oil base to 5% crude coal tar in petrolatum or the oil base without tar. The tar extract in oil plus suberythemogenic UVB produced significantly more rapid improvement than the oil base plus UVB. The direct bilateral comparison of equal concentrations of tar extract in oil base versus crude coal tar in petrolatum in a suberythemogenic UV photo regimen revealed no statistical differences between treatments. In a study comparing tar extract in oil and the oil base without ultraviolet radiation, the tar extract in oil side responded more rapidly.

  4. Higher temperature coal tar enamel fights corrosion

    SciTech Connect

    Johnson, J.R.; Henegar, S.; Roder, B.

    1996-10-01

    High temperatures create new challenges for pipeline coatings. Cracking, adhesion breakdown and electrochemical corrosion are accelerated by higher service temperatures. A new epoxy primer/coal tar pipeline coating system utilizes the latent heat of the coal tar application to fully cure the newly developed primer to achieve outstanding bonding integrity and high temperature cathodic disbondment resistance. A key reason for this overall high performance is the marriage of a newly developed epoxy primer that provides outstanding adhesion with coal tar enamel, which provides excellent long-term water resistance. The paper describes experimental studies, pilot plant application, cathodic disbondment testing, and results from hot water soak tests and the low temperature cracking test.

  5. 40 CFR 721.10532 - Tar, brown coal.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Tar, brown coal. 721.10532 Section 721... Tar, brown coal. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as tar, brown coal (PMN P-12-167, CAS No. 101316-83-0) is subject...

  6. 40 CFR 721.10532 - Tar, brown coal.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Tar, brown coal. 721.10532 Section 721... Tar, brown coal. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as tar, brown coal (PMN P-12-167, CAS No. 101316-83-0) is subject...

  7. Investigation of coal tar mobility at a former MGP site

    SciTech Connect

    Moo-Young, H.K.; Mo, X.H.; Waterman, R.; Coleman, A.; Saroff, S.

    2009-11-15

    The presence of coal tar in the subsurface of former manufactured gas plant sites poses an environmental hazard and a potential threat to public health. Coal tar can release various chemical compounds that are transported into the groundwater. Before any efforts can be made to remove coal tar from contaminated subsurface soils, it is recommended to characterize coal tar properties and composition and to delineate the residual saturation point between mobile and immobile coal tar. This paper presents a new innovative field device, the Res-SAT field tool, and laboratory procedures that can be used to determine the saturation-capillary pressure relationship for a soil-water coal-tar system and the critical pressure for coal tar mobility.

  8. VAPOR PRESSURES AND HEATS OF VAPORIZATION OF PRIMARY COAL TARS

    SciTech Connect

    Eric M. Suuberg; Vahur Oja

    1997-07-01

    This project had as its main focus the determination of vapor pressures of coal pyrolysis tars. It involved performing measurements of these vapor pressures and from them, developing vapor pressure correlations suitable for use in advanced pyrolysis models (those models which explicitly account for mass transport limitations). This report is divided into five main chapters. Each chapter is a relatively stand-alone section. Chapter A reviews the general nature of coal tars and gives a summary of existing vapor pressure correlations for coal tars and model compounds. Chapter B summarizes the main experimental approaches for coal tar preparation and characterization which have been used throughout the project. Chapter C is concerned with the selection of the model compounds for coal pyrolysis tars and reviews the data available to us on the vapor pressures of high boiling point aromatic compounds. This chapter also deals with the question of identifying factors that govern the vapor pressures of coal tar model materials and their mixtures. Chapter D covers the vapor pressures and heats of vaporization of primary cellulose tars. Chapter E discusses the results of the main focus of this study. In summary, this work provides improved understanding of the volatility of coal and cellulose pyrolysis tars. It has resulted in new experimentally verified vapor pressure correlations for use in pyrolysis models. Further research on this topic should aim at developing general vapor pressure correlations for all coal tars, based on their molecular weight together with certain specific chemical characteristics i.e. hydroxyl group content.

  9. Preparation of meso-carbon microbeads from coal tars

    SciTech Connect

    Ling, L.C.; Liu, L.; Zhang, B.J.; Wu, D.

    1997-12-31

    Coal tar (CT0) with 3.7wt% primary pyridine insoluble fraction (PI) was chosen as the raw material to prepare mesocarbon microbeads (MCMB). The tar was filtered to remove PI, obtaining PI-free coal tar (CT1). CT0, CT1 and their mixtures with different proportions were carbonized under pressure for 2 hours respectively. The polymerizates were filtered, and the residues were extracted with pyridine, and thus MCMB was obtained as a pyridine insoluble fraction. Both the yield and the size of resultant MCMB increased with the decreasing of primary PI content in raw coal tars. No clear evidence was observed that the primary PI particles exhibited active sites during the formation of MCMB, while it`s certain that they restricted coalescence between mesophase spheres.

  10. Purifying filter-clogging coal tar formed from low-temperature coal carbonization

    SciTech Connect

    Kokot, H.; Romey, I.

    1980-11-04

    A process is provided for purifying filter-clogging coal tar residue of the type obtained by low-temperature carbonization of coal. Such coal tar residues include viscous organic coal tar constituents, particulate solid impurities and liquid water. Applicants' process includes the step of heating coal at 450*-700* C. At least substantially in the absence of air to thereby decompose the coal to products including coal tar, the coal tar being of the type containing liquid water, particulate solid impurities, and viscous organic coal tar constituents including light oils, the light oils incidentally combining with the liquid water to produce a filter-clogging emulsion. The thusformed coal tar is then heated to a temperature above the boiling point of water and sufficiently high to thereby distill off substantially all of the water and the light oils to thereby obtain an intermediate product which is substantially free from the presence of liquid water and light oil constituents which in combination form a filter-clogging emulsion. Finally, the intermediate product is subsequently filtered to thereby separate the particulate solid impurities from the undistilled viscous constituents of the coal tar.

  11. Ultrasound assisted, thermally activated persulfate oxidation of coal tar DNAPLs.

    PubMed

    Peng, Libin; Wang, Li; Hu, Xingting; Wu, Peihui; Wang, Xueqing; Huang, Chumei; Wang, Xiangyang; Deng, Dayi

    2016-11-15

    The feasibility of ultrasound assisted, thermally activated persulfate for effective oxidation of twenty 2-6 ringed coal tar PAHs in a biphasic tar/water system and a triphasic tar/soil/water system were investigated and established. The results indicate that ultrasonic assistance, persulfate and elevated reaction temperature are all required to achieve effective oxidation of coal tar PAHs, while the heating needed can be provided by ultrasonic induced heating as well. Further kinetic analysis reveals that the oxidation of individual PAH in the biphasic tar/water system follows the first-order kinetics, and individual PAH oxidation rate is primary determined by the mass transfer coefficients, tar/water interfacial areas, the aqueous solubility of individual PAH and its concentration in coal tar. Based on the kinetic analysis and experimental results, the contributions of ultrasound, persulfate and elevated reaction temperature to PAHs oxidation were characterized, and the effects of ultrasonic intensity and oxidant dosage on PAHs oxidation efficiency were investigated. In addition, the results indicate that individual PAH degradability is closely related to its reactivity as well, and the high reactivity of 4-6 ringed PAHs substantially improves their degradability. PMID:27450342

  12. Biogeochemical gradients above a coal tar DNAPL.

    PubMed

    Scherr, Kerstin E; Backes, Diana; Scarlett, Alan G; Lantschbauer, Wolfgang; Nahold, Manfred

    2016-09-01

    Naturally occurring distribution and attenuation processes can keep hydrocarbon emissions from dense non aqueous phase liquids (DNAPL) into the adjacent groundwater at a minimum. In a historically coal tar DNAPL-impacted site, the de facto absence of a plume sparked investigations regarding the character of natural attenuation and DNAPL resolubilization processes at the site. Steep vertical gradients of polycyclic aromatic hydrocarbons, microbial community composition, secondary water quality and redox-parameters were found to occur between the DNAPL-proximal and shallow waters. While methanogenic and mixed-electron acceptor conditions prevailed close to the DNAPL, aerobic conditions and very low dissolved contaminant concentrations were identified in three meters vertical distance from the phase. Comprehensive two-dimensional gas chromatography-mass spectrometry (GC×GC-MS) proved to be an efficient tool to characterize the behavior of the present complex contaminant mixture. Medium to low bioavailability of ferric iron and manganese oxides of aquifer samples was detected via incubation with Shewanella alga and evidence for iron and manganese reduction was collected. In contrast, 16S rDNA phylogenetic analysis revealed the absence of common iron reducing bacteria. Aerobic hydrocarbon degraders were abundant in shallow horizons, while nitrate reducers were dominating in deeper aquifer regions, in addition to a low relative abundance of methanogenic archaea. Partial Least Squares - Canonical Correspondence Analysis (PLS-CCA) suggested that nitrate and oxygen concentrations had the greatest impact on aquifer community structure in on- and offsite wells, which had a similarly high biodiversity (H' and Chao1). Overall, slow hydrocarbon dissolution from the DNAPL appears to dominate natural attenuation processes. This site may serve as a model for developing legal and technical strategies for the treatment of DNAPL-impacted sites where contaminant plumes are absent or

  13. Biodegradation of naphthalene from coal tar. Research progress report

    SciTech Connect

    Ghoshal, S.; Ramaswami, A.; Luthy, R.G.

    1994-02-07

    Biodegradation experiments were conducted to evaluate the mineralization of naphthalene released from coal tar entrapped in microporous silica media. Tests were performed with two coal tars recovered from former manufactured gas plant sites. Results from these tests showed that the degradation end point for naphthalene was significantly lower than the total amount of naphthalene present in coal tar. The role of physico-chemical and biological processes on the rate of biotransformation of naphthalene was evaluated. Mass transfer rates for dissolution of naphthalene from entrapped coal tar were measured in batch, flow-through systems. The rate of naphthalene mass transfer from the coal tar was found to be significantly greater than the rate of naphthalene biomineralization in batch slurry reactors. This implied that the rate acting factor for the biodegradation process was related to biokinetic phenomena rather than mass transfer processes. Further tests indicated that conditions inhibitory to bacteria limited the biodegradation of naphthalene, and in some cases the inhibition was reversible upon dilution of the reactor contents.

  14. 29 CFR 1910.1002 - Coal tar pitch volatiles; interpretation of term.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 6 2012-07-01 2012-07-01 false Coal tar pitch volatiles; interpretation of term. 1910.1002... Hazardous Substances § 1910.1002 Coal tar pitch volatiles; interpretation of term. As used in § 1910.1000 (Table Z-1), coal tar pitch volatiles include the fused polycyclic hydrocarbons which volatilize from...

  15. 29 CFR 1910.1002 - Coal tar pitch volatiles; interpretation of term.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 6 2010-07-01 2010-07-01 false Coal tar pitch volatiles; interpretation of term. 1910.1002... Hazardous Substances § 1910.1002 Coal tar pitch volatiles; interpretation of term. As used in § 1910.1000 (Table Z-1), coal tar pitch volatiles include the fused polycyclic hydrocarbons which volatilize from...

  16. 29 CFR 1910.1002 - Coal tar pitch volatiles; interpretation of term.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 6 2013-07-01 2013-07-01 false Coal tar pitch volatiles; interpretation of term. 1910.1002... Hazardous Substances § 1910.1002 Coal tar pitch volatiles; interpretation of term. As used in § 1910.1000 (Table Z-1), coal tar pitch volatiles include the fused polycyclic hydrocarbons which volatilize from...

  17. 29 CFR 1910.1002 - Coal tar pitch volatiles; interpretation of term.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 6 2014-07-01 2013-07-01 true Coal tar pitch volatiles; interpretation of term. 1910.1002... Hazardous Substances § 1910.1002 Coal tar pitch volatiles; interpretation of term. As used in § 1910.1000 (Table Z-1), coal tar pitch volatiles include the fused polycyclic hydrocarbons which volatilize from...

  18. Coal tar analysis by LC/MS

    SciTech Connect

    Herod, A.A.; Ladner, W.R.; Stokes, B.J.; Berry, A.J.; Games, D.E.

    1986-04-01

    The application of LC/MS to the analysis of an aromatic fraction of a hydropyrolysis tar is described. The results are compared with those obtained by GC/MS, low eV probe mass spectrometry and field desorption mass spectrometry.

  19. Release of polyaromatic hydrocarbons from coal tar contaminated soils

    SciTech Connect

    Priddy, N.D.; Lee, L.S.

    1996-11-01

    A variety of process wastes generated from manufactured gas production (MGP) have contaminated soils and groundwater at production and disposal sites. Coal tar, consisting of a complex mixture of hydrocarbons present as a nonaqueous phase liquid, makes up a large portion of MGP wastes. Of the compounds in coal tar, polyaromatic hydrocarbons (PAHs) are the major constituents of environmental concern due to their potential mutagenic and carcinogenic hazards. Characterization of the release of PAHs from the waste-soil matrix is essential to quantifying long-term environmental impacts in soils and groundwater. Currently, conservative estimates for the release of PAHs to the groundwater are made assuming equilibrium conditions and using relationships derived from artificially contaminated soils. Preliminary work suggests that aged coal tar contaminated soils have much lower rates of desorption and a greater affinity for retaining organic contaminants. To obtain better estimates of desorption rates, the release of PAHs from a coal tar soil was investigated using a flow-interruption, miscible displacement technique. Methanol/water solutions were employed to enhance PAH concentrations above limits of detection. For each methanol/water solution employed, a series of flow interrupts of varying times was invoked. Release rates from each methanol/water solution were estimated from the increase in concentration with duration of flow interruption. Aqueous-phase release rates were then estimated by extrapolation using a log-linear cosolvency model.

  20. CONTROL TECHNOLOGIES FOR PARTICULATE AND TAR EMISSIONS FROM COAL CONVERTERS

    EPA Science Inventory

    The report gives results of a characterization of solid and tar particulate emissions in raw product gases from several types of coal gasifiers, in terms of their total quantities, chemical composition, and size distribution. Fixed-bed gasifiers produce the smallest particulate l...

  1. Glove permeation by shale oil and coal tar extract

    SciTech Connect

    Nelson, G.O.; Carlson, G.J.; Buerer, A.L.

    1980-02-14

    The vapor penetration of shale oil and coal tar extract through protective gloves composed of either polyethylene, polyvinyl chloride, vinyl, latex, neoprene, Buna-N, acrylonitrile, natural rubber, or nitrile rubber was tested and measured. We used flame ionization techniques to determine the permeation characteristics of the gloves. Neoprene, Buna-N, acrylonitrile and nitrile gloves offered the best protection against the vapors tested.

  2. Coal tar-containing asphalt - resource or hazardous waste?

    SciTech Connect

    Andersson-Skold, Y.; Andersson, K.; Lind, B.; Claesson, A.; Larsson, L.; Suer, P.; Jacobson, T.

    2007-09-30

    Coal tar was used in Sweden for the production of asphalt and for the drenching of stabilization gravel until 1973. The tar has high concentrations of polycyclic aromatic hydrocarbons (PAH), some of which may be strongly carcinogenic. Approximately 20 million tonnes of tar-containing asphalt is present in the public roads in Sweden. Used asphalt from rebuilding can be classified as hazardous waste according to the Swedish Waste Act. The cost of treating the material removed as hazardous waste can be very high due to the large amount that has to be treated, and the total environmental benefit is unclear. The transport of used asphalt to landfill or combustion will affect other environmental targets. The present project, based on three case studies of road projects in Sweden, evaluates the consequences of four scenarios for handling the material: reuse, landfill, biological treatment, and incineration. The results show that reuse of the coal tar-containing materials in new road construction is the most favorable alternative in terms of cost, material use, land use, energy consumption, and air emissions.

  3. 29 CFR 1910.1002 - Coal tar pitch volatiles; interpretation of term.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... distillation residues of coal, petroleum (excluding asphalt), wood, and other organic matter. Asphalt (CAS 8052-42-4, and CAS 64742-93-4) is not covered under the “coal tar pitch volatiles” standard....

  4. 29 CFR 1926.1102 - Coal tar pitch volatiles; interpretation of term.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 8 2012-07-01 2012-07-01 false Coal tar pitch volatiles; interpretation of term. 1926.1102 Section 1926.1102 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH... Hazardous Substances § 1926.1102 Coal tar pitch volatiles; interpretation of term. Note: The...

  5. 29 CFR 1915.1002 - Coal tar pitch volatiles; interpretation of term.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Coal tar pitch volatiles; interpretation of term. 1915.1002 Section 1915.1002 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH... Toxic and Hazardous Substances § 1915.1002 Coal tar pitch volatiles; interpretation of term. Note:...

  6. 29 CFR 1926.1102 - Coal tar pitch volatiles; interpretation of term.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 8 2014-07-01 2014-07-01 false Coal tar pitch volatiles; interpretation of term. 1926.1102 Section 1926.1102 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH... Hazardous Substances § 1926.1102 Coal tar pitch volatiles; interpretation of term. Note: The...

  7. 29 CFR 1915.1002 - Coal tar pitch volatiles; interpretation of term.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 7 2013-07-01 2013-07-01 false Coal tar pitch volatiles; interpretation of term. 1915.1002 Section 1915.1002 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH... Toxic and Hazardous Substances § 1915.1002 Coal tar pitch volatiles; interpretation of term. Note:...

  8. 29 CFR 1926.1102 - Coal tar pitch volatiles; interpretation of term.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Coal tar pitch volatiles; interpretation of term. 1926.1102 Section 1926.1102 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH... Hazardous Substances § 1926.1102 Coal tar pitch volatiles; interpretation of term. Note: The...

  9. 29 CFR 1926.1102 - Coal tar pitch volatiles; interpretation of term.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 8 2011-07-01 2011-07-01 false Coal tar pitch volatiles; interpretation of term. 1926.1102 Section 1926.1102 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH... Hazardous Substances § 1926.1102 Coal tar pitch volatiles; interpretation of term. Note: The...

  10. 29 CFR 1915.1002 - Coal tar pitch volatiles; interpretation of term.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 7 2012-07-01 2012-07-01 false Coal tar pitch volatiles; interpretation of term. 1915.1002 Section 1915.1002 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH... Toxic and Hazardous Substances § 1915.1002 Coal tar pitch volatiles; interpretation of term. Note:...

  11. 29 CFR 1915.1002 - Coal tar pitch volatiles; interpretation of term.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 7 2014-07-01 2014-07-01 false Coal tar pitch volatiles; interpretation of term. 1915.1002 Section 1915.1002 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH... Toxic and Hazardous Substances § 1915.1002 Coal tar pitch volatiles; interpretation of term. Note:...

  12. 29 CFR 1915.1002 - Coal tar pitch volatiles; interpretation of term.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false Coal tar pitch volatiles; interpretation of term. 1915.1002 Section 1915.1002 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH... Toxic and Hazardous Substances § 1915.1002 Coal tar pitch volatiles; interpretation of term. Note:...

  13. Cultivation of yeast on light-oil fractions of hard-coal tar

    SciTech Connect

    Kucher, R.V.; Dzumeozei, N.V.; Pavlyuk, M.I.; Tyrovskii, A.A.

    1982-01-01

    The results are given of experiments on the cultivation of the yeast Candida tropicalis on light-oil fractions of coal-tar. It has been shown that a light fraction can serve as the sole source of carbon and energy. Surface active agents stimulate the growth of the yeast on the light-oil fractions of hard-coal tar.

  14. Carbazole is a naturally occurring inhibitor of angiogenesis and inflammation isolated from antipsoriatic coal tar

    SciTech Connect

    Jack L. Arbiser; Baskaran Govindarajan; Traci E. Battle; Rebecca Lynch; David A. Frank; Masuko Ushio-Fukai; Betsy N. Perry; David F. Stern; G. Tim Bowden; Anquan Liu; Eva Klein; Pawel J. Kolodziejski; N. Tony Eissa; Chowdhury F. Hossain; Dale G. Nagle

    2006-06-15

    Coal tar is one of the oldest and an effective treatment for psoriasis. Coal tar has been directly applied to the skin, or used in combination with UV light as part of the Goeckerman treatment. The use of coal tar has caused long-term remissions in psoriasis, but has fallen out of favor because the treatment requires hospitalization and coal tar is poorly acceptable aesthetically to patients. Thus, determining the active antipsoriatic component of coal tar is of considerable therapeutic interest. We fractionated coal tar into its components, and tested them using the SVR angiogenesis inhibitor assay. Treatment of SVR endothelial cells with coal tar fractions resulted in the isolation of a single fraction with antiangiogenic activity. The active antiangiogenic compound in coal tar is carbazole. In addition to antiangiogenic activity, carbazole inhibited the production of inflammatory IL-15 by human mononuclear cells. IL-15 is elevated in psoriasis and is thought to contribute to psoriatic inflammation. Carbazole treatment also reduced activity of inducible nitric oxide synthase (iNOS), which is proinflammatory and elevated in psoriasis. The effect of carbazole on upstream pathways in human psoriasis was determined, and carbazole was shown to inhibit signal transducer and activator of transcription (stat)3-mediated transcription, which has been shown to be relevant in human psoriasis. IL-15, iNOS, and stat3 activation require the activation of the small GTPase rac for optimal activity. Carbazole was found to inhibit rac activation as a mechanism for its inhibition of downstream inflammatory and angiogenic pathways. Given its antiangiogenic and anti-inflammatory activities, carbazole is likely a major component of the antipsoriatic activity of coal tar. Carbazole and derivatives may be useful in the therapy of human psoriasis.

  15. Coal-tar-based pavement sealcoat—Potential concerns for human health and aquatic life

    USGS Publications Warehouse

    Mahler, Barbara J.; Woodside, Michael D.; Van Metre, Peter C.

    2016-01-01

    Aquatic Life Concerns—Runoff from coal-tar-sealcoated pavement, even runoff collected more than 3 months after sealcoat application, is acutely toxic to fathead minnows and water fleas, two species commonly used to assess toxicity to aquatic life. Exposure to even highly diluted runoff from coal-tar-sealcoated pavement can cause DNA damage and impair DNA repair. These findings demonstrate that coal-tar-sealcoat runoff can remain a risk to aquatic life for months after application.

  16. Kinetics of co-pyrolysis of sawdust, coal and tar.

    PubMed

    Montiano, M G; Díaz-Faes, E; Barriocanal, C

    2016-04-01

    Two coals, sawdust and coal tar were selected to prepare briquettes. Thermogravimetric analyses at three heating rates (i.e. 10, 20 and 30°C/min) and up to 1000°C were carried out with the briquette components. Four blends were prepared and the experimental decomposition profiles were compared with the calculated data taking into account the amount of each component in the blend. No interaction was found when comparing the experimental and calculated decomposition profiles of the blends. Isoconversional models OFW (Ozawa-Flynn-Wall) and KAS (Kissinger-Akahira-Sunose) were used to obtain the activation energies of the blend components. The activation energies obtained were introduced in the Coats-Redfern (CR) model to derive the pre-exponential factors. The thermal decomposition profiles calculated using the kinetic parameters were in good agreement with the experimental results in the case of the briquette components, but worse results were obtained in the case of the blends due to their greater complexity. PMID:26829530

  17. Coal tar, material used in soil improvement for use in road engineering

    NASA Astrophysics Data System (ADS)

    Ochoa Díaz, R.; Montañez, A.; Cuentas, J.

    2016-02-01

    Coal tar is a by-product of coal distillation in the absence of oxygen to obtain metallurgical coke; its colour varies from dark coffee to black, slightly viscous and its density is greater than that of water. Taking into account the previous characteristics, this document presents a study of the feasibility of using coal tar for the improvement of physical properties, mechanics and dynamics of materials used in road engineering. In this way, the origin, characteristics, and properties of tar are first described. Next, its combination with which granular-based material is evaluated through the CBR test procedure to determine its resistance and to compare it with the non-stabilized material. Finally, the behaviour of the material when subjected to dead loads by means of resistant modules found with the NAT (Nottingham Asphalt Tester) is explored. As a result, the option of using coal tar as a stabilizer was identified due to its use under specific conditions.

  18. Relation Between PAHs and Coal-Tar-Based Pavement Sealant in Urban Environments (Invited)

    NASA Astrophysics Data System (ADS)

    Mahler, B. J.; van Metre, P. C.

    2010-12-01

    Since 2003, coal-tar-based sealant products have come under increased scrutiny as a source of PAHs in urban environments. Sealant (or sealcoat) is the black, shiny substance often applied to asphalt pavement, in particular parking lots and driveways, for esthetic and maintenance purposes. Coal-tar-based sealant, one of the two primary pavement sealant types on the market, typically is 20-35 percent coal-tar pitch, a known carcinogen that is more than 50 percent polycyclic aromatic hydrocarbons (PAHs). The PAH content of the coal-tar-based sealant product is about 1,000 times that of a similar, asphalt-based product, on average. This difference is reflected in regional differences in sealant use and PAH concentrations in pavement dust. In the central and eastern U.S., where the coal-tar-based formulation is prevalent, ΣPAH in mobile particles from sealed pavement have been shown to be about 1,000 times higher than in the western U.S., where the asphalt-based formulation is prevalent (the median ΣPAH concentrations are 2,200 mg/kg in the central and eastern U.S. and 2.1 mg/kg in the western U.S.). Source apportionment modeling indicates that, in the central and eastern U.S., particles from sealed pavement are contributing the majority of the PAHs in recently deposited (post-1990) lake sediment, with implications for ecological health, and that coal-tar-based sealant is the primary cause of upward trends in PAHs in U.S. urban lakes. From the standpoint of human health, research indicates that mobile particles from parking lots with coal-tar-based sealant are tracked indoors, resulting in elevated PAH concentrations in house dust. Coal-tar-based sealcoat being applied to an asphalt parking lot at the University of Texas Pickle Research Center.

  19. [Effect of coal tar on cignolin erythema--1 hour treatment of psoriasis with high-dose cignolin with and without tar].

    PubMed

    Schauder, S; Mahrle, G

    1985-06-01

    Coal tar applied simultaneously showed a suppressive effect on anthralin erythema. This effect was demonstrated by an epicutaneous test 24 hours (27 patients) and 1 hour (46 patients) after application of various concentrations of anthralin combined with tar 3%. In a clinical study on 9 patients, anthralin 3% alone or combined with tar 10% were administered in a right and left comparison on symmetrical chronic psoriatic lesions for 1 hour daily. Anthralin plus tar exhibited a stronger anti-psoriatic effect than anthralin alone did. Tar reduced the anthralin erythema in the perilesional skin. These findings favor the combination of coal tar and anthralin in the 1-hour treatment schedule of psoriasis. PMID:3160177

  20. Biogeochemical characterisation of a coal tar distillate plume.

    PubMed

    Williams, G M; Pickup, R W; Thornton, S F; Lerner, D N; Mallinson, H E; Moore, Y; White, C

    2001-12-15

    The distillation of acidified coal tars for up to 50 years has given rise to a phenol plume approximately 500 m long, 50 m deep and containing up to 15 g l(-1) dissolved organic carbon (DOC) in the Triassic Sandstones aquifer. A conceptual biogeochemical model based on chemical and microbiological analysis of groundwater samples has been developed as a preliminary to more detailed studies of the controls on natural attenuation. While the development of redox zones and the production of methane and carbon dioxide provide evidence of natural attenuation, it appears that degradation is slow. The existence of sulphate in the plume indicates that this electron acceptor has not been depleted and that consequently methanogenesis is probably limited. Based on a simple estimate of sulphate input concentration, a half-life of about 15 years has been estimated for sulphate reduction. Geochemical modelling predicts that increased alkalinity within the plume has not led to carbonate precipitation, and thus within the limits of accuracy of the measurement, alkalinity may reflect the degree of biodegradation. This implies a loss of around 18% of the DOC over a 30-year period. Despite limited degradation, microbial studies show that there are diverse microbial communities in the aquifer with the potential for both anaerobic and aerobic biodegradation. Microbial activity was found to be greatest at the leading edge of the plume where DOC concentrations are 60 mg l(-1) or less, but activity could still be observed in more contaminated samples even though cells could not be cultured. The study suggests that degradation may be limited by the high phenol concentrations within the core of the plume, but that once diluted by dispersion, natural attenuation may proceed. More detailed studies to confirm these initial findings are identified and form the basis of associated papers. PMID:11820470

  1. A photographic method for estimating wear of coal tar sealcoat from parking lots

    SciTech Connect

    Mateo Scoggins; Tom Ennis; Nathan Parker; Chris Herrington

    2009-07-01

    Coal-tar-based sealcoat has been recognized as an important source of PAHs to the environment through wear and transport via stormwater runoff. Sealcoat removal rates have not been measured or even estimated in the literature due to the complex array of physical and chemical process involved. A photographic study was conducted that incorporates all sources of wear using 10 coal tar-sealed parking lots in Austin, Texas, with sealcoat age ranging from 0 to 5 years. Randomly located photographs from each parking lot were analyzed digitally to quantify black sealed areas versus lighter colored unsealed areas at the pixel level. The results indicate that coal tar sealcoat wears off of the driving areas of parking lots at a rate of approximately 4.7% per year, and from the parking areas of the lots at a rate of approximately 1.4% per year. The overall annual loss of sealcoat was calculated at 2.4%. This results in an annual delivery to the environment of 0.51 g of PAHs per m{sup 2} of coal tar-sealed parking lot. These values provide a more robust and much higher estimate of loading of PAHs from coal tar sealcoated parking lots when compared to other available measures. 20 refs., 6 figs.

  2. Field scale characterization and modeling of contaminant release from a coal tar source zone

    NASA Astrophysics Data System (ADS)

    D'Affonseca, Fernando M.; Blum, Philipp; Finkel, Michael; Melzer, Reiner; Grathwohl, Peter

    2008-11-01

    A coal tar contaminated site was characterized using traditional and innovative investigation methods. A careful interpretation of hydrogeological and hydrogeochemical data allowed for the conceptualization of the heterogeneous coal tar distribution in the subsurface. Past and future contaminant release from the source zone was calculated using a modeling framework consisting of a three-dimensional steady-state groundwater flow model (MODFLOW) and two hydrogeochemical models (MIN3P). Computational time of long-term simulations was reduced by simplifying the coal tar composition using 3 composite and 2 individual constituents and sequential application of a 2D centerline model (for calibration and predictions) and a 3D model (only for predictions). Predictions were carried out for a period of 1000 years. The results reveal that contaminant mass flux is governed by the geometry of zones containing residual coal tar, amount of coal tar, its composition and the physicochemical properties of the constituents. The long-term predictions made using the 2D model show that even after 1000 years, source depletion will be small with respect to phenanthrene, 89% of initial mass will be still available, and for the moderately and sparingly soluble composite constituents, 60% and 98%, respectively.

  3. Energy and environmental research emphasizing low-rank coal: Task 3.9 catalytic tar cracking

    SciTech Connect

    Timpe, R.C.

    1995-09-01

    Tar produced in the gasification of coal is deleterious to the operation of downstream equipment, including fuel cells, gas turbines, hot-gas stream cleanup filters, and pressure-swing absorption systems. Catalytic cracking of tars to smaller hydrocarbons can be an effective means of removing these tars from gas streams and, in the process, generating useful products, such as methane gas, which is crucial to operation of molten carbonate fuel cells. Aerosol tars are not readily removed from gas streams by conventional means and, as a consequence, often end up plugging filters or fouling fuel cells, turbines, or sorbents. Catalytic cracking of these tars to molecular moieties of C{sub 10} or smaller would prevent the problems commonly attributed to the tars. As an example, the moving Bourdon fixed-bed gasifier, by virtue of its efficient countercurrent heat exchange and widespread commercial use, may offer the lowest-cost integrated gasification combined-cycle (IGCC) system if tar generation and wastewater contamination can be minimized. We evaluate the potential of selected catalysts to minimize tar accumulation and maximize char conversion to useful liquid and/or gaseous products. Owing to the potential for production of extremely toxic nickel carbonyl gas, care must be exercised in the use of a NISMM catalyst for cracking tars at high temperatures in reducing atmospheres such as those produced by coal gasification. We observed a fifty percent or more of tar produced during steam gasification of Beulah lignite at temperatures of 400{degrees}-800+{degrees}C when cracked by either dolomite or zeolite maintained at a temperature of 50{degrees}C-100{degrees}C below that of the reactor.

  4. Analytical study on mesocarbon microbeads derived from coal tar pitch

    SciTech Connect

    Zhang, Y.; Murata, S.; Nomura, M.

    1999-07-01

    provide complete information about structures of pitches. Thus, the combination of different analytical techniques seems to be best for the characterization of such materials. The first objective of this paper is to give an insight into structural features of two kinds of mesocarbon microbeads (MCMB) derived from different coal tar pitches, by conducting butylation of MCMB with butyl iodide catalyzed by dibutylzinc and characterizing their butylated products according to conventional techniques. The second one is to differentiate two MCMB in terms of chemical structure based on IR, SEM and Raman spectroscopy. Most of this information is extracted from the authors' earlier and just completed papers, cited in the references.

  5. Effects of model coal tar components on adhesion strength of polyurethane coating on steel plate

    SciTech Connect

    Yokoyama, N.; Fujino, K.

    2005-04-15

    In order to study the effects of coal tar components on the adhesion strength of a heavy duty anticorrosive coating formed with tar-urethane resin oil on a steel plate, polyurethane coatings that were compounded with 15 kinds of polycyclic aromatic compounds as model coal tar components were prepared. In the model coal tar, components, naphthalene, quinoline, 2-naphthol, and phenanthrene showed good compatibility with polyurethane. To test their heavy duty anticorrosive properties, tensile adhesion strength of the cured coatings prepared with the compatible model coal tar components was measured, and the change in tensile adhesion strength as a function of time during salt-water spray treatment was measured. We found that the systems compounded with naphthalene, 2-naphthol, and phenanthrene showed good properties in an ordinary state for adhesion strength. However, only the system with 2-naphthol was found to have good properties in the change of tensile adhesion strength as a function or time during salt-water spray treatment. The curing time of the system with 2-naphthol was slower than that or the others, i.e., we found an inverse proportion between curing speed and adhesion durability. We also measured the dynamic viscoelasticity of cured coatings.

  6. Feasibility for the use of coal tar as a new material for road surfaces (pavement) construction

    NASA Astrophysics Data System (ADS)

    Romero Farfán, M. A.; Murillo Vega, H. E.; Trujillo Pinto, F. A.

    2016-02-01

    The stabilization products often used to improve the support of granular layers in the construction of road surfaces may be expensive and difficult to get. Therefore, it is necessary to test different materials, which are cheap and easy to obtain, and which will enhance the physical and mechanical properties of pavement layers. This document evaluates the use of coal tar, as a stabilizer for granular subbase. Initially, with a description of tar properties, determining the optimal conditions for the granular subbase material compaction, by means of modified proctor tests and the calculation of the resistance of the unaltered material by using CBR lab tests (California Bearing Ratio). Afterwards, with the design and development of granular material mixes with different percentages of coal tar and determining its CBR as comparative parameter with that of the unaltered material. Finally, by calculating the optimal coal tar percentage in order to stabilize the subbase granular, the results showed an improvement in the resistance of the granular material and a decrease in its expansion due to the use of coal tar.

  7. Vapor pressures and heats of vaporization of primary coal tars. Quarterly technical progress report, July 1--September 30, 1995

    SciTech Connect

    Suuberg, E.M.

    1995-12-31

    There is significant current interest in general area of coal pyrolysis, particularly because of the central role of pyrolysis in all thermally driven coal conversion processes-gasification, combustion, liquefaction, mild gasification, or thermal beneficiation. There remain several key data needs in these application areas. Among them is a need for more reliable correlation for prediction of vapor pressure of heavy, primary coal tars. The vapor pressure correlations that exist at present for coal tars are very crude and they are not considered reliable to even an order of magnitude when applied to tars. The present project seeks to address this important gap in the near term by direct measurement of vapor pressures of coal tar fractions, by application of well-established techniques and modifications thereof. The principal objectives of the program are to: (1) obtain data on the vapor pressures and heats of vaporization of tars from a range of ranks of coal, (2) develop correlations based on a minimum set of conveniently measurable characteristics of the tars, (3) develop equipment that would allow performing such measurements in a reliable, straightforward fashion. A significant amount of time has been devoted during this quarter to extending the work on measurements of vapor pressures of tars. For this purpose, cellulose tar and cellulose tar related compounds have been selected as model systems. Cellulose tar has a much narrower distribution of molecular weight than does coal tar, and it is much more homogeneous. Thus it is better to develop the methods to be used for coal tars on this simpler model system first.

  8. Coal tar phototoxicity: characteristics of the smarting reaction

    SciTech Connect

    Diette, K.M.; Gange, R.W.; Stern, R.S.; Arndt, K.A.; Parrish, J.A.

    1985-04-01

    The properties and ultraviolet exposure parameters of tar smarts were examined in an effort to elucidate the mechanisms involved. It was show that irradiation with 1 minimal smarting dose (MSD) of UVA immediately following tar removal lowered the MSD for 6 h, demonstrated by subsequent challenge with UVA. Following 3 MSDs this memory effect was demonstrable for 24 h. The smarting reaction was area dependent--smaller areas of exposure require higher doses of UVA to induce smarting. Smarting followed reciprocity over a 6-fold range of irradiances (2-12.5 mW/cm2) but higher irradiances required higher doses of UVA, perhaps due to a delay in the recognition and reporting of smarting. The smarting reaction and delayed erythema due to UVA and tar were equally blocked by sunscreen.

  9. Skin cancer in patients with psoriasis treated with coal tar. A 25-year follow-up study

    SciTech Connect

    Pittelkow, M.R.; Perry, H.O.; Muller, S.A.; Maughan, W.Z.; O'Brien, P.C.

    1981-08-01

    For many years, crude coal tar has been used for the treatment of psoriasis. The possible carcinogenic effect of crude coal tar and ultraviolet (UV) radiation (Goeckerman regimen), considered individually or in combination, has been of some concern to physicians. A 25-year follow-up study was completed on 280 patients with psoriasis who were hospitalized and treated with crude coal tar and UV radiation at the Mayo Clinic, Rochester, Minn, during the years 1950 through 1954. The results of this study suggest that the incidence of skin cancer is not appreciably increased above the expected incidence for the general population when patients are treated with coal tar ointments. It seems that the Goeckerman regimen (topical crude coal tar combined with UV radiation) can be used with minimal risk for skin cancer in the treatment of psoriasis.

  10. Coal-tar-based pavement sealcoat, polycyclic aromatic Hydrocarbons (PAHs), and environmental health

    USGS Publications Warehouse

    Mahler, B.J.; Van Metre, P.C.

    2011-01-01

    Studies by the U.S. Geological Survey (USGS) have identified coal-tar-based sealcoat-the black, viscous liquid sprayed or painted on asphalt pavement such as parking lots-as a major source of polycyclic aromatic hydrocarbon (PAH) contamination in urban areas for large parts of the Nation. Several PAHs are suspected human carcinogens and are toxic to aquatic life.

  11. PAHs underfoot: Contaminated dust from coal-tar sealcoated pavement is widespread in the United States

    USGS Publications Warehouse

    Van Metre, P.C.; Mahler, B.J.; Wilson, J.T.

    2009-01-01

    We reported in 2005 that runoff from parking lots treated with coal-tar-based sealcoat was a major source of polycyclic aromatic hydrocarbons (PAHs) to streams in Austin, Texas. Here we present new data from nine U. S. cities that show nationwide patterns in concentrations of PAHs associated with sealcoat Dust was swept from parking lots in six cities in the central and eastern U. S., where coal-tar-based sealcoat dominates use, and three cities in the western U. S., where asphalt-based sealcoat dominates use. For six central and eastern cities, median ?? PAH concentrations in dust from sealcoated and unsealcoated pavement are 2200 and 27 mg/kg, respectively. For three western cities, median ?? PAH concentrations in dust from sealcoated and unsealcoated pavement are similar and very low (2. 1 and 0. 8 mg/kg, respectively). Lakes in the central and eastern cities where pavement was sampled have bottom sediments with higher PAH concentrations than do those in the western cities relative to degree of urbanization. Bottom-sediment PAH assemblages are similar to those of sealcoated pavement dust regionally, implicating coal-tar-based sealcoat as a PAH source to the central and eastern lakes. Concentrations of benzo[a]pyrene in dust from coal-tar sealcoated pavement and adjacent soils greatly exceed generic soil screening levels, suggesting that research on human-health risk is warranted.

  12. 21 CFR 740.18 - Coal tar hair dyes posing a risk of cancer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 7 2012-04-01 2012-04-01 false Coal tar hair dyes posing a risk of cancer. 740.18... posing a risk of cancer. (a) The principal display panel of the label and any labeling accompanying a... your skin and has been determined to cause cancer in laboratory animals. (b) Hair dyes containing...

  13. 21 CFR 740.18 - Coal tar hair dyes posing a risk of cancer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 7 2013-04-01 2013-04-01 false Coal tar hair dyes posing a risk of cancer. 740.18... posing a risk of cancer. (a) The principal display panel of the label and any labeling accompanying a... your skin and has been determined to cause cancer in laboratory animals. (b) Hair dyes containing...

  14. 21 CFR 740.18 - Coal tar hair dyes posing a risk of cancer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 7 2011-04-01 2010-04-01 true Coal tar hair dyes posing a risk of cancer. 740.18... posing a risk of cancer. (a) The principal display panel of the label and any labeling accompanying a... your skin and has been determined to cause cancer in laboratory animals. (b) Hair dyes containing...

  15. 21 CFR 740.18 - Coal tar hair dyes posing a risk of cancer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Coal tar hair dyes posing a risk of cancer. 740.18... posing a risk of cancer. (a) The principal display panel of the label and any labeling accompanying a... your skin and has been determined to cause cancer in laboratory animals. (b) Hair dyes containing...

  16. 21 CFR 740.18 - Coal tar hair dyes posing a risk of cancer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 7 2014-04-01 2014-04-01 false Coal tar hair dyes posing a risk of cancer. 740.18... posing a risk of cancer. (a) The principal display panel of the label and any labeling accompanying a... your skin and has been determined to cause cancer in laboratory animals. (b) Hair dyes containing...

  17. Time scales of organic contaminant dissolution from complex source zones: coal tar pools vs. blobs

    NASA Astrophysics Data System (ADS)

    Eberhardt, Christina; Grathwohl, Peter

    2002-11-01

    Groundwater contamination due to complex organic mixtures such as coal tar, creosote and fuels is a widespread problem in industrialized regions. Although most compounds in these mixtures are biodegradable, the contaminant sources are very persistent for many decades after the contamination occurred (e.g., more than 100 years ago at gasworks sites). This limited bioavailability is due to slow dissolution processes. This study presents results from a large scale tank experiment (8 m long) on the long-term (354 days) dissolution kinetics of BTEX and PAHs from a 2.5 m long coal tar pool and 0.5 m long (smear) zone containing coal tar blobs distributed in a coarse sand. The results indicate (1) that Raoult's law holds for estimation of the saturation aqueous concentrations of the coal tar constituents, (2) that for the dissolution of smear zones longer than approximately 0.1 m and with more than 3-5% residual saturation, the local equilibrium assumption is valid and (3) that although very small (<0.1 mm), the transverse vertical dispersivity dominates the pool dissolution processes. Typical time scales for removal of the pollutants from the blob zone and the pool are in the order of a few weeks to more than 10,000 years, respectively.

  18. Time scales of organic contaminant dissolution from complex source zones: coal tar pools vs. blobs.

    PubMed

    Eberhardt, Christina; Grathwohl, Peter

    2002-11-01

    Groundwater contamination due to complex organic mixtures such as coal tar, creosote and fuels is a widespread problem in industrialized regions. Although most compounds in these mixtures are biodegradable, the contaminant sources are very persistent for many decades after the contamination occurred (e.g., more than 100 years ago at gasworks sites). This limited bioavailability is due to slow dissolution processes. This study presents results from a large scale tank experiment (8 m long) on the long-term (354 days) dissolution kinetics of BTEX and PAHs from a 2.5 m long coal tar pool and 0.5 m long (smear) zone containing coal tar blobs distributed in a coarse sand. The results inidicate (1) that Raoult's law holds for estimation of the saturation aqueous concentrations of the coal tar constituents, (2) that for the dissolution of smear zones longer than approximately 0.1 m and with more than 3-5% residual saturation, the local equilibrium assumption is valid and (3) that although very small (< 0.1 mm), the transverse vertical dispersivity dominates the pool dissolution processes. Typical time scales for removal of the pollutants from the blob zone and the pool are in the order of a few weeks to more than 10,000 years, respectively. PMID:12683639

  19. PAHs underfoot: contaminated dust from coal-tar sealcoated pavement is widespread in the United States

    SciTech Connect

    Peter C. Van Metre; Barbara J. Mahler; Jennifer T. Wilson

    2009-01-15

    We reported in 2005 that runoff from parking lots treated with coal-tar-based sealcoat was a major source of polycyclic aromatic hydrocarbons (PAHs) to streams in Austin, Texas. Here we present new data from nine U.S. cities that show nationwide patterns in concentrations of {Sigma}PAHs associated with sealcoat. Dust was swept from parking lots in six cities in the central and eastern U.S., where coal-tar-based sealcoat dominates use, and three cities in the western U.S., where asphalt-based sealcoat dominates use. For six central and eastern cities, median SPAH concentrations in dust from sealcoated and unsealcoated pavement are 2200 and 27 mg/kg, respectively. For three western cities, median SPAH concentrations in dust from sealcoated and unsealcoated pavement are similar and very low (2.1 and 0.8 mg/kg, respectively). Lakes in the central and eastern cities where pavement was sampled have bottom sediments with higher PAH concentrations than do those in the western cities relative to degree of urbanization. Bottom-sediment PAH assemblages are similar to those of sealcoated pavement dust regionally, implicating coal-tar-based sealcoat as a PAH source to the central and eastern lakes. Concentrations of benzo(a)pyrene in dust from coal-tar sealcoated pavement and adjacent soils greatly exceed generic soil screening levels, suggesting that research on human-health risk is warranted. 30 refs., 4 figs., 2 tabs.

  20. Implication of Coal Tar and Asphalt on Black Carbon Quantification in Urban Watersheds

    NASA Astrophysics Data System (ADS)

    Yang, Y.; Werth, C. J.; Ligouis, B.; Razzaque, M.

    2008-12-01

    Sorption to black carbon (BC) is an important process that controls the transport and fate of persistent organic pollutants in aquatic environments. Efforts have been made to measure BC in different environmental matrices including aerosols, soils, and sediments; however, few studies have attempted to evaluate BC in dust from urban streets or parking lots, which can be an important BC source in urban lake sediments. Methods to quantify BC in soils and sediments usually involve the removal of non-BC carbonaceous materials with chemical and/or thermal oxidation followed by elemental analysis. The presence of coal tar pitch and asphalt in urban pavement dust is hypothesized to potentially result in an overestimate of BC. The primary objectives of this research are to identify the distribution of BC in a small urban watershed and to investigate the potential interference from coal tar and asphalt on BC quantification by method intercomparison. Samples were collected from the Lake Como watershed in Fort Worth, Texas. They include dust from coal-tar-sealed and unsealed parking lots and residential streets, soils from residential and commercial areas, stream bed sediments, and lake sediment cores. After density separation, samples were subjected to sequential chemical treatments and thermal treatment. Commercial coal tar pitch and asphalt products were subjected to these same treatments for comparison. BC contents quantified with chemical treatment and chemo-thermal oxidation at 375°C (CTO-375) were compared with those characterized using organic petrography. The chemical treatment predicted greater BC contents than organic petrography in all samples, and the greatest difference is in the sealed parking lot dust. CTO-375 method also predicted greater BC content in this sample than organic petrography. Commercial coal tar pitch was resistant to thermal oxidation and both coal tar pitch and asphalt were resistant to the chemical treatment. These results indicate that

  1. Potential contributions of asphalt and coal tar to black carbon quantification in urban dust, soils, and sediments

    USGS Publications Warehouse

    Yang, Y.; Mahler, B.J.; Van Metre, P.C.; Ligouis, B.; Werth, C.J.

    2010-01-01

    Measurements of black carbon (BC) using either chemical or thermal oxidation methods are generally thought to indicate the amount of char and/or soot present in a sample. In urban environments, however, asphalt and coal-tar particles worn from pavement are ubiquitous and, because of their pyrogenic origin, could contribute to measurements of BC. Here we explored the effect of the presence of asphalt and coal-tar particles on the quantification of BC in a range of urban environmental sample types, and evaluated biases in the different methods used for quantifying BC. Samples evaluated were pavement dust, residential and commercial area soils, lake sediments from a small urban watershed, and reference materials of asphalt and coal tar. Total BC was quantified using chemical treatment through acid dichromate (Cr2O7) oxidation and chemo-thermal oxidation at 375??C (CTO-375). BC species, including soot and char/charcoal, asphalt, and coal tar, were quantified with organic petrographic analysis. Comparison of results by the two oxidation methods and organic petrography indicates that both coal tar and asphalt contribute to BC quantified by Cr2O7 oxidation, and that coal tar contributes to BC quantified by CTO-375. These results are supported by treatment of asphalt and coal-tar reference samples with Cr2O7 oxidation and CTO-375. The reference asphalt is resistant to Cr2O7 oxidation but not to CTO-375, and the reference coal tar is resistant to both Cr2O7 oxidation and CTO-375. These results indicate that coal tar and/or asphalt can contribute to BC measurements in samples from urban areas using Cr2O7 oxidation or CTO-375, and caution is advised when interpreting BC measurements made with these methods. ?? 2010 Elsevier Ltd.

  2. Allergies

    MedlinePlus

    ... up within a week. Learn More about Allergies Food Allergies: What You Need to Know Environmental Protection Agency ... Resources for You Allergy Relief for Your Child Food Allergies: Reducing the Risks Allergy Meds Could Affect Your ...

  3. Effect of the bioemulsifier emulsan on naphthalene mineralization from coal tar in aqueous systems

    SciTech Connect

    Skubal, K.L.; Luthy, R.G.

    1994-09-01

    Coal tar in aerobic aqueous systems was treated with purified emulsan, the anionic heteropolysaccharide bioemulsifier produced by Acinetobacter calcoaceticus RAG-1; with inocula of various concentrations of stationary phase RAG-1 cells; or with cell-free broth from stationary phase RAG-1 cultures. Naphthalene mineralization by a mixed PAH-degrading population was measured by recovering {sup 14}CO{sub 2} evolved during biotransformation of the [{sup 14}C]naphthalene-labeled coal tar. There was no evidence of naphthalene mineralization by RAG- 1 cells alone. The addition of emulsan, RAG-1 inocula, or cell-free broth to systems containing the PAH-degrading population did not significantly affect naphthalene mineralization in any of the systems tested. Coal tar in these experiments was present either as a free dense nonaqueous phase liquid (DNAPL), or as DNAPL imbibed into microporous silica particles. Emulsification of the tar was not observed in either case. The presence or absence of microporous silica did not affect the extent or rate of naphthalene mineralization, nor did the concentration of RAG-1 inocula or the amount of broth added. The addition of cell-free broth, emulsan, or RAG-1 cells late in the experiments did not yield significantly different results compared to initial addition of these substances. Thus, emulsan and related fractions from RAG-1 cultures were ineffective in altering naphthalene mineralization in this study.

  4. Vapor pressures and heats of vaporization of primary coal tars. Quarterly technical progress report, April 1--June 30, 1995

    SciTech Connect

    Suuberg, E.M.

    1995-10-01

    The vapor pressure correlations that exist at present for coal tars are very crude and they are not considered reliable to even an order of magnitude when applied to tars. The present project seeks to address this important gap in the near term by direct measurement of vapor pressures of coal tar fractions, by application of well-established techniques and modifications thereof. The principal objectives of the program are to: (1) obtain data on the vapor pressures and heats of vaporization of tars from a range of ranks of coal, (2) develop correlations based on a minimum set of conveniently measurable characteristics of the tars, (3) develop equipment that would allow performing such measurements in a reliable, straightforward fashion. Both the gas saturation method and the Knudsen effusion method are being used. Results are presented for anthracene, naphthacene, pentacene, and a mixture of anthracene and perylene obtained using the effusion method.

  5. Preparation of Organic Light-Emitting Diode Using Coal Tar Pitch, a Low-Cost Material, for Printable Devices

    PubMed Central

    Yamaoka, Miki; Asami, Shun-suke; Funaki, Nayuta; Kimura, Sho; Yingjie, Liao; Fukuda, Takeshi; Yamashita, Makoto

    2013-01-01

    We have identified coal tar pitch, a very cheap organic material made from coal during the iron-making process, as a source from which could be obtained emissive molecules for organic light-emitting diodes. Coal tar pitch was separated by simple dissolution in organic solvent, and subsequent separation by preparative thin-layer chromatography was used to obtain emissive organic molecules. The retardation factor of preparative thin-layer chromatography played a major role in deciding the emission characteristics of the solution as photoluminescence spectra and emission-excitation matrix spectra could be controlled by modifying the solution preparation method. In addition, the device characteristics could be improved by modifying the solution preparation method. Two rounds of preparative thin-layer chromatography separation could improve the luminance of organic light-emitting diodes with coal tar pitch, indicating that less polar components are favorable for enhancing the luminance and device performance. By appropriate choice of the solvent, the photoluminescence peak wavelength of separated coal tar pitch could be shifted from 429 nm (cyclohexane) to 550 nm (chloroform), and consequently, the optical properties of the coal tar pitch solution could be easily tuned. Hence, the use of such multicomponent materials is advantageous for fine-tuning the net properties at a low cost. Furthermore, an indium tin oxide/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/coal tar pitch/LiF/Al system, in which the emissive layer was formed by spin-coating a tetrahydrofuran solution of coal tar pitch on the substrate, showed a luminance of 176 cd/m2. In addition, the emission spectrum of coal tar pitch was narrowed after the preparative thin-layer chromatography process by removing the excess emissive molecules. PMID:23667539

  6. Ground-water contamination by organic bases derived from coal-tar wastes

    USGS Publications Warehouse

    Pereira, Wilfred E.; Rostad, Colleen E.; Garbarino, John R.; Hult, Marc F.

    1983-01-01

    A fluid sample from a shallow aquifer contaminated by coal-tar wastes was analyzed for organic bases. The sample consisted of a mixture of aqueous and oily-tar phases. The phases were separated by centrifugation and filtration. Organic bases were isolated from each phase by pH adjustment and solvent extraction. Organic bases in the oily-tar phase were further purified by neutral-alumina, micro-column adsorption chromatography. Separation and identification of the organic bases in each phase were achieved by using capillary gas chromatography-mass spectrometry-computer (GC-MS-COM) and probe distillation-high resolution mass spectrometry (PD-HRMS) techniques. Organic bases present in the aqueous phase included primary aromatic amines (such as aniline, alkylated anilines, and naphthylamines) as well as azaarenes (such as alkylated pyridines, quinolines, acridine, and benzoquinolines). The oily-tar phase contained acridine, benzacridines, dibenzacridines, and numerous other azaarenes, the elemental compositions of which were determined by PD-HRMS. Azaarenes in the oily-tar phase, varying in size from 6 to 12 rings, are reported for the first time. The origin and environmental significance of these compounds are discussed.

  7. Groundwater contamination by organic bases derived from coal-tar wastes

    USGS Publications Warehouse

    Pereira, W.E.; Rostad, C.E.; Garbarino, J.R.; Hult, M.F.

    1983-01-01

    A fluid sample from a shallow aquifer contaminated by coal-tar wastes was analyzed for organic bases. The sample consisted of a mixture of aqueous and oily-tar phases. The phases were separated by centrifugation and filtration. Organic bases were isolated from each phase by pH adjustment and solvent extraction. Organic bases in the oily-tar phase were further purified by neutral-alumina, micro-column adsorption chromatography. Separation and identification of the organic bases in each phase were achieved by using capillary gas chromatography-mass spectrometry-computer (GC-MS-COM) and probe distillation-high resolution mass spectrometry (PD-HRMS) techniques. Organic bases present in the aqueous phase included primary aromatic amines (such as aniline, alkylated anilines, and naphthylamines) as well as azaarenes (such as alkylated pyridines, quinolines, acridine, and benzoquinolines). The oily-tar phase contained acridine, benzacridines, dibenzacridines, and numerous other azaarenes, the elemental compositions of which were determined by PD-HRMS. Azaarenes in the oily-tar phase, varying in size from 6 to 12 rings, are reported for the first time. The origin and environmental significance of these compounds are discussed. ?? 1983.

  8. Mineralization of PAH's in a Coal-Tar Impacted Aquifer Sediments and Associated Microbial Community Structure Investigated with FISH

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The microbial community structure and mineralization of polycyclic aromatic hydrocarbons (PAHs) in a coal-tar contaminated aquifer were investigated spatially using fluorescence in situ hybridization and with laboratory-scale incubations. Microbial populations in the contaminated sediments were thr...

  9. Mineralization Of PAHs In Coal-Tar Impacted Aquifer Sediments And Associated Microbial Community Structure Investigated With FISH

    EPA Science Inventory

    The microbial community structure and mineralization of polycyclic aromatic hydrocarbons (PAHs) in a coal-tar contaminated aquifer were investigated spatially using fluorescence in situ hybridization (FISH) and in laboratory-scale incubations of the aquifer sediments. DAPI-detect...

  10. Effect of cavitation on the properties of coal-tar pitch as studied by gas-liquid chromatography

    SciTech Connect

    M.I. Baikenov; T.B. Omarbekov; S.K. Amerkhanova

    2008-02-15

    The applicability of the cavitation-wave effect to coal-tar pitch processing is considered. The results of the GLC analysis of the test material before and after rotor-pulsation cavitation treatment are given. The organic matter of coal-tar pitch was found to degrade upon cavitation; as a result of this, the yields of light and medium fractions considerably increased. 5 refs., 2 figs., 4 tabs.

  11. Coal-tar pavement sealants might substantially increase children's PAH exposures

    USGS Publications Warehouse

    Williams, E. Spencer; Mahler, Barbara J.; Van Metre, Peter C.

    2012-01-01

    Dietary ingestion has been identified repeatedly as the primary route of human exposure to polycyclic aromatic hydrocarbons (PAHs), seven of which are classified as probable human carcinogens (B2 PAHs) by the U.S. EPA. Humans are exposed to PAHs through ingestion of cooked and uncooked foods, incidental ingestion of soil and dust, inhalation of ambient air, and absorption through skin. Although PAH sources are ubiquitous in the environment, one recently identified PAH source stands out: Coal-tar-based pavement sealant—a product applied to many parking lots, driveways, and even playgrounds primarily in the central, southern, and eastern U.S.—has PAH concentrations 100–1000 times greater than most other PAH sources. It was reported recently that PAH concentrations in house dust in residences adjacent to parking lots with coal-tar-based sealant were 25 times higher than in residences adjacent to unsealed asphalt parking lots.

  12. Importance of heterocylic aromatic compounds in monitored natural attenuation for coal tar contaminated aquifers: A review.

    PubMed

    Blum, Philipp; Sagner, Anne; Tiehm, Andreas; Martus, Peter; Wendel, Thomas; Grathwohl, Peter

    2011-11-01

    NSO heterocycles (HET) are typical constituents of coal tars. However, HET are not yet routinely monitored, although HET are relatively toxic coal tar constituents. The main objectives of the study is therefore to review previous studies and to analyse HET at coal tar polluted sites in order to assess the relevance of HET as part of monitored natural attenuation (MNA) or any other long-term monitoring programme. Hence, natural attenuation of typical HET (indole, quinoline, carbazole, acridine, methylquinolines, thiophene, benzothiophene, dibenzothiophene, benzofuran, dibenzofuran, methylbenzofurans, dimethylbenzofurans and xanthene) were studied at three different field sites in Germany. Compound-specific plume lengths were determined for all main contaminant groups (BTEX, PAH and HET). The results show that the observed plume lengths are site-specific and are above 250m, but less than 1000m. The latter, i.e. the upper limit, however mainly depends on the level of investigation, the considered compound, the lowest measured concentration and/or the achieved compound-specific detection limit and therefore cannot be unequivocally defined. All downstream contaminant plumes exhibited HET concentrations above typical PAH concentrations indicating that some HET are generally persistent towards biodegradation compared to other coal tar constituents, which results in comparatively increased field-derived half-lives of HET. Additionally, this study provides a review on physicochemical and toxicological parameters of HET. For three well investigated sites in Germany, the biodegradation of HET is quantified using the centre line method (CLM) for the evaluation of bulk attenuation rate constants. The results of the present and previous studies suggest that implementation of a comprehensive monitoring programme for heterocyclic aromatic compounds is relevant at sites, if MNA is considered in risk assessment and for remediation. PMID:22115084

  13. Volatilization of polycyclic aromatic hydrocarbons from coal-tar-sealed pavement

    USGS Publications Warehouse

    Van Metre, Peter C.; Majewski, Michael S.; Mahler, Barbara J.; Foreman, William T.; Braun, Christopher L.; Wilson, Jennifer T.; Burbank, Teresa L.

    2012-01-01

    Coal-tar-based pavement sealants, a major source of PAHs to urban water bodies, are a potential source of volatile PAHs to the atmosphere. An initial assessment of volatilization of PAHs from coal-tar-sealed pavement is presented here in which we measured summertime gas-phase PAH concentrations 0.03 m and 1.28 m above the pavement surface of seven sealed (six with coal-tar-based sealant and one with asphalt-based sealant) and three unsealed (two asphalt and one concrete) parking lots in central Texas. PAHs also were measured in parking lot dust. The geometric mean concentration of the sum of eight frequently detected PAHs (ΣPAH8) in the 0.03-m samples above sealed lots (1320 ng m-3) during the hottest part of the day was 20 times greater than that above unsealed lots (66.5 ng m-3). The geometric mean concentration in the 1.28-m samples above sealed lots (138 ng m-3) was five times greater than above unsealed lots (26.0 ng m-3). Estimated PAH flux from the sealed lots was 60 times greater than that from unsealed lots (geometric means of 88 and 1.4 μg m-2 h-1, respectively). Although the data set presented here is small, the much higher estimated fluxes from sealed pavement than from unsealed pavement indicate that coal-tar-based sealants are emitting PAHs to urban air at high rates compared to other paved surfaces.

  14. Cancer risk from incidental ingestion exposures to PAHs associated with coal-tar-sealed pavement

    USGS Publications Warehouse

    Williams, E. Spencer; Mahler, Barbara J.; Van Metre, Peter C.

    2012-01-01

    Recent (2009-10) studies documented significantly higher concentrations of polycyclic aromatic hydrocarbons (PAHs) in settled house dust in living spaces and soil adjacent to parking lots sealed with coal-tar-based products. To date, no studies have examined the potential human health effects of PAHs from these products in dust and soil. Here we present the results of an analysis of potential cancer risk associated with incidental ingestion exposures to PAHs in settings near coal-tar-sealed pavement. Exposures to benzo[a]pyrene equivalents were characterized across five scenarios. The central tendency estimate of excess cancer risk resulting from lifetime exposures to soil and dust from nondietary ingestion in these settings exceeded 1 × 10–4, as determined using deterministic and probabilistic methods. Soil was the primary driver of risk, but according to probabilistic calculations, reasonable maximum exposure to affected house dust in the first 6 years of life was sufficient to generate an estimated excess lifetime cancer risk of 6 × 10–5. Our results indicate that the presence of coal-tar-based pavement sealants is associated with significant increases in estimated excess lifetime cancer risk for nearby residents. Much of this calculated excess risk arises from exposures to PAHs in early childhood (i.e., 0–6 years of age).

  15. Oil shale, tar sand, coal research, advanced exploratory process technology jointly sponsored research

    SciTech Connect

    Not Available

    1992-01-01

    Accomplishments for the quarter are presented for the following areas of research: oil shale, tar sand, coal, advanced exploratory process technology, and jointly sponsored research. Oil shale research includes; oil shale process studies, environmental base studies for oil shale, and miscellaneous basic concept studies. Tar sand research covers process development. Coal research includes; underground coal gasification, coal combustion, integrated coal processing concepts, and solid waste management. Advanced exploratory process technology includes; advanced process concepts, advanced mitigation concepts, and oil and gas technology. Jointly sponsored research includes: organic and inorganic hazardous waste stabilization; development and validation of a standard test method for sequential batch extraction fluid; operation and evaluation of the CO[sub 2] HUFF-N-PUFF Process; fly ash binder for unsurfaced road aggregates; solid state NMR analysis of Mesa Verde Group, Greater Green River Basin, tight gas sands; flow-loop testing of double-wall pipe for thermal applications; characterization of petroleum residue; shallow oil production using horizontal wells with enhanced recovery techniques; and menu driven access to the WDEQ Hydrologic Data Management Systems.

  16. Use of metal hydrous titanium oxide catalysts to enhance coal tar yield via hydropyrolysis

    SciTech Connect

    Klavetter, E.A.; Stephens, H.P.; Dosch, R.G.

    1990-01-01

    Catalytic hydropyrolysis experiments performed in this project on several US and UK coals have established that tar yields in excess of 70% (daf basis) and conversions (100%-char) in excess of 80% can be achieved from bituminous coals containing 80--84% dmmf carbon using hydrous titanium oxide (HTO) catalysts with low concentrations of active metals. Total conversion approaches the reactive maceral contents for these coals. Previously performed two-stage catalytic hydropyrolysis experiments have demonstrated that high yields of liquid products with high H/C ratios, low heteroatom contents, and a significant concentration of light naphtha can be achieved. The objectives of this research are to determine suitable methods for catalyzing the hydropyrolysis process and to investigate the reactions and mechanisms responsible for the high conversion of coal materials to distillable liquids via direct catalytic hydropyrolysis. Recently developed hydrous titanium oxide (HTO)-supported catalysts have received encouraging results in direct coal liquefaction applications. Results of hydropyrolysis experiment using Mo and Pd HTO catalysts coated directly onto the coal are presented here and compared with results from experiments using uncatalyzed coal samples and using a dispersed MoS{sub 2} catalyst. The effect of coal rank, active metals concentration, dispersion method, and metal type are discussed. 9 refs., 6 figs., 2 tabs.

  17. Oil shale, tar sand, coal research advanced exploratory process technology, jointly sponsored research

    SciTech Connect

    Speight, J.G.

    1992-01-01

    Accomplishments for the past quarter are presented for the following five tasks: oil shale; tar sand; coal; advanced exploratory process technology; and jointly sponsored research. Oil shale research covers oil shale process studies. Tar sand research is on process development of Recycle Oil Pyrolysis and Extraction (ROPE) Process. Coal research covers: coal combustion; integrated coal processing concepts; and solid waste management. Advanced exploratory process technology includes: advanced process concepts;advanced mitigation concepts; and oil and gas technology. Jointly sponsored research includes: organic and inorganic hazardous waste stabilization; CROW field demonstration with Bell Lumber and Pole; development and validation of a standard test method for sequential batch extraction fluid; PGI demonstration project; operation and evaluation of the CO[sub 2] HUFF-N-PUFF Process; fly ash binder for unsurfaced road aggregates; solid state NMR analysis of Mesaverde Group, Greater Green River Basin, tight gas sands; flow-loop testing of double-wall pipe for thermal applications; characterization of petroleum residue; shallow oil production using horizontal wells with enhanced oil recovery techniques; surface process study for oil recovery using a thermal extraction process; NMR analysis of samples from the ocean drilling program; in situ treatment of manufactured gas plant contaminated soils demonstration program; and solid state NMR analysis of naturally and artificially matured kerogens.

  18. Determination of the Forms of Nitrogen Released in Coal Tar During Rapid Devolatilization

    SciTech Connect

    Thomas H. Fletcher

    1998-05-30

    The primary objective of this work is to determine the forms of nitrogen in coal that lead to nitrogen release during devolatilization. Experiments are to be performed in two existing laminar flow reactors available at Brigham Young University, which are both capable of temperatures (up to 2000 K), particle heating rates (10 4 to 10 5 K/s), and residence times (up to 500 ms) relevant to conditions commonly encountered in industrial pulverized coal combustors. The forms of nitrogen in coal, char, and tar samples are analyzed using state-of-the-art techniques, including nuclear magnetic resonance (NMR), X-Ray photoelectron spectroscopy (XPS), and high resolution nitrogen-specific chromatography. These sophisticated analysis techniques are being performed in collaboration with other researchers at BYU, the University of Utah, and industrial organizations. Coals have been obtained as a function of rank, including eight coals from the University of Utah that are to be used in pilot scale tests in support of the DOE Coal-2000 HiPPS (High Performance Power Systems) and LEBS (Low-Emission Boiler Systems) programs. Anticipated results from the proposed research are (a) nitrogen release parameters during devolatilization for specific coals pertinent to the HiPPS and LEBS projects, (b) better fundamental understanding of the chemistry of nitrogen release, and (c) a nitrogen release submodel based on fundamental chemistry that may be more widely applicable than existing empirical relationships.

  19. DETERMINATION OF THE FORMS OF NITROGEN RELEASED IN COAL TAR DURING RAPID DEVOLATILIZATION

    SciTech Connect

    1998-10-30

    The primary objective of this work is to determine the forms of nitrogen in coal that lead to nitrogen release during devolatilization. Experiments are to be performed in two existing laminar flow reactors available at Brigham Young University, which are both capable of temperatures (up to 2000 K), particle heating rates (10 4 to 10 5 K/s), and residence times (up to 500 ms) relevant to conditions commonly encountered in industrial pulverized coal combustors. The forms of nitrogen in coal, char, and tar samples are analyzed using state-of-the-art techniques, including nuclear magnetic resonance (NMR), X-Ray photoelectron spectroscopy (XPS), and high resolution nitrogen-specific chromatography. These sophisticated analysis techniques are being performed in collaboration with other researchers at BYU, the University of Utah, and industrial organizations. Coals have been obtained as a function of rank, including eight coals from the University of Utah that are to be used in pilot scale tests in support of the DOE Coal-2000 HiPPS (High Performance Power Systems) and LEBS (Low-Emission Boiler Systems) programs. Results from the proposed research are (a) nitrogen release parameters during devolatilization for specific coals pertinent to the HiPPS and LEBS projects, (b) better fundamental understanding of the chemistry of nitrogen release, and (c) a nitrogen release submodel based on fundamental chemistry that may be more widely applicable than existing empirical relationships.

  20. Determination of the forms of nitrogen released in coal tar during rapid devolatilization

    SciTech Connect

    Fletcher, T.H.

    1996-10-31

    The primary objective of this work is determined the forms of nitrogen in coal that lead to nitrogen release during devolatilization. Experiments are to be performed in two existing laminar flow reactors available at Brigham Young University, which are both capable of temperatures (up to 2000 K), particle heating rates (10{sup 4} to 10{sup 5} K/s), and residence times (up to 500 ms) relevant to conditions commonly encountered in industrial pulverized coal combustors. the forms of nitrogen in coal, char, and tar samples will be analyzed using state-of-the-art techniques, including nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy (XPS), and high resolution nitrogen-specific chromatography. These sophisticated analysis techniques will be preformed in collaboration with other research at BYU, the University of Utah, and industrial organizations. Coals will be obtained as a function of rank, including eight coals from the University of Utah that are to be used in pilot scale tests in support of the DOE Coal-2000 HiPPS (high Performance Power Systems) and LEBS (Low-Emission Boiler Systems) program. Anticipated results from the proposed research will be (a) nitrogen release parameters during devolatilization for specific coals pertinent to the HiPPS and LEBS projects, (b) better fundamental understanding of the chemistry of nitrogen release, and (c) a nitrogen release submodel based on fundamental chemistry that may be more widely applicable than existing empirical relationships.

  1. Implications of Use of Coal-Tar-Based Pavement Sealcoat on Urban Water Quality

    NASA Astrophysics Data System (ADS)

    Van Metre, P. C.

    2015-12-01

    Coal-tar-based (CT) sealcoat is used to protect and improve the appearance of asphalt pavement of driveways and parking lots primarily in the central and eastern U.S. and in Canada. CT sealcoat typically is 20 to 35% crude coal tar or coal-tar pitch and contains from 50,000 to 100,000 mg/kg polycyclic aromatic hydrocarbons (PAH), about 1,000 times more than asphalt-based (AS) sealcoat or asphalt itself. Tires and snowplows abrade the friable sealcoat surface into fine particles—median total PAH concentrations in dust from CT-sealcoated pavement are 2,200 mg/kg compared to a median concentration of 11 mg/kg for dust from unsealed pavement. Use of CT sealcoat has several implications for urban streams and lakes. Source apportionment modeling has indicated that, in regions where CT sealcoat is prevalent, particles from sealcoated pavement are contributing the majority of the PAHs to recently deposited lake sediment, often resulting in sediment concentrations above toxicity thresholds based on effects-based sediment quality guidelines. Acute 2-day laboratory toxicity testing of simulated runoff from CT-sealcoated pavement to a cladoceran (Ceriodaphnia dubia) and fathead minnows (Pimephales promelas) demonstrated that toxicity continues for samples collected for weeks or months following sealcoat application and that toxicity is enhanced by exposure to UV light. Using the fish-liver cell line RTL-W1, runoff collected as much as 36 days following CT-sealcoat application has been demonstrated to cause DNA damage and impair DNA repair capacity. These results demonstrate that CT runoff is a potential hazard to aquatic ecosystems and that exposure to sunlight can enhance toxicity and genetic damage. Recent research has provided direct evidence that restricting use of CT sealcoat in a watershed can lead to a substantial reduction in PAH concentrations in receiving water bodies.

  2. PAH volatilization following application of coal-tar-based pavement sealant

    USGS Publications Warehouse

    Van Metre, Peter C.; Majewski, Michael S.; Mahler, Barbara J.; Foreman, William T.; Braun, Christopher L.; Wilson, Jennifer T.; Burbank, Teresa L.

    2012-01-01

    Coal-tar-based pavement sealants, a major source of PAHs to urban water bodies, have recently been identified as a source of volatile PAHs to the atmosphere. We tracked the volatilization of PAHs for 1 year after application of a coal-tar-based pavement sealant by measuring gas-phase PAH concentrations above the pavement surface and solid-phase PAH concentrations in sealant scraped from the surface. Gas-phase concentrations at two heights (0.03 and 1.28 m) and wind speed were used to estimate volatilization flux. The sum of the concentrations of eight frequently detected PAHs (ΣPAH8) in the 0.03-m sample 1.6 h after application (297,000 ng m-3) was about 5000 times greater than that previously reported for the same height above unsealed parking lots (66 ng m-3). Flux at 1.6 h after application was estimated at 45,000 μg m-2 h-1 and decreased rapidly during the 45 days after application to 160 μg m-2 h-1. Loss of PAHs from the adhered sealant also was rapid, with about a 50% decrease in solid-phase ΣPAH8 concentration over the 45 days after application. There was general agreement, given the uncertainties, in the estimated mass of ΣPAH8 lost to the atmosphere on the basis of air sampling (2–3 g m-2) and adhered sealant sampling (6 g m-2) during the first 16 days after application, translating to a loss to the atmosphere of one-quarter to one-half of the PAHs in the sealcoat product. Combining the estimated mass of ΣPAH8 released to the atmosphere with a national-use estimate of coal-tar-based sealant suggests that PAH emissions from new coal-tar-based sealcoat applications each year (~1000 Mg) are larger than annual vehicle emissions of PAHs for the United States.

  3. PAH volatilization following application of coal-tar-based pavement sealant

    NASA Astrophysics Data System (ADS)

    Van Metre, Peter C.; Majewski, Michael S.; Mahler, Barbara J.; Foreman, William T.; Braun, Christopher L.; Wilson, Jennifer T.; Burbank, Teresa L.

    2012-05-01

    Coal-tar-based pavement sealants, a major source of PAHs to urban water bodies, have recently been identified as a source of volatile PAHs to the atmosphere. We tracked the volatilization of PAHs for 1 year after application of a coal-tar-based pavement sealant by measuring gas-phase PAH concentrations above the pavement surface and solid-phase PAH concentrations in sealant scraped from the surface. Gas-phase concentrations at two heights (0.03 and 1.28 m) and wind speed were used to estimate volatilization flux. The sum of the concentrations of eight frequently detected PAHs (ΣPAH8) in the 0.03-m sample 1.6 h after application (297,000 ng m-3) was about 5000 times greater than that previously reported for the same height above unsealed parking lots (66 ng m-3). Flux at 1.6 h after application was estimated at 45,000 μg m-2 h-1 and decreased rapidly during the 45 days after application to 160 μg m-2 h-1. Loss of PAHs from the adhered sealant also was rapid, with about a 50% decrease in solid-phase ΣPAH8 concentration over the 45 days after application. There was general agreement, given the uncertainties, in the estimated mass of ΣPAH8 lost to the atmosphere on the basis of air sampling (2-3 g m-2) and adhered sealant sampling (6 g m-2) during the first 16 days after application, translating to a loss to the atmosphere of one-quarter to one-half of the PAHs in the sealcoat product. Combining the estimated mass of ΣPAH8 released to the atmosphere with a national-use estimate of coal-tar-based sealant suggests that PAH emissions from new coal-tar-based sealcoat applications each year (˜1000 Mg) are larger than annual vehicle emissions of PAHs for the United States.

  4. Phase-equilibria for design of coal-gasification processes: dew points of hot gases containing condensible tars. Final report

    SciTech Connect

    Prausnitz, J.M.

    1980-05-01

    This research is concerned with the fundamental physical chemistry and thermodynamics of condensation of tars (dew points) from the vapor phase at advanced temperatures and pressures. Fundamental quantitative understanding of dew points is important for rational design of heat exchangers to recover sensible heat from hot, tar-containing gases that are produced in coal gasification. This report includes essentially six contributions toward establishing the desired understanding: (1) Characterization of Coal Tars for Dew-Point Calculations; (2) Fugacity Coefficients for Dew-Point Calculations in Coal-Gasification Process Design; (3) Vapor Pressures of High-Molecular-Weight Hydrocarbons; (4) Estimation of Vapor Pressures of High-Boiling Fractions in Liquefied Fossil Fuels Containing Heteroatoms Nitrogen or Sulfur; and (5) Vapor Pressures of Heavy Liquid Hydrocarbons by a Group-Contribution Method.

  5. Epoxy-borax-coal tar composition for a radiation protective, burn resistant drum liner and centrifugal casting method

    DOEpatents

    Taylor, Robert S.; Boyer, Norman W.

    1980-01-01

    A boron containing burn resistant, low level radiation protection material useful, for example, as a liner for radioactive waste disposal and storage, a component for neutron absorber, and a shield for a neutron source. The material is basically composed of Borax in the range of 25-50%, coal tar in the range of 25-37.5%, with the remainder being an epoxy resin mix. A preferred composition is 50% Borax, 25% coal tar and 25% epoxy resin. The material is not susceptible to burning and is about 1/5 the cost of existing radiation protection material utilized in similar applications.

  6. Epoxy-borax-coal tar composition for a radiation protective, burn resistant drum liner and centrifugal casting method

    SciTech Connect

    Boyer, N.W.; Taylor, R.S.

    1980-10-28

    A boron containing burn resistant, low level radiation protection material useful, for example, as a liner for radioactive waste disposal and storage, a component for neutron absorber, and a shield for a neutron source. The material is basically composed of borax in the range of 25-50%, coal tar in the range of 25-37.5%, with the remainder being an epoxy resin mix. A preferred composition is 50% borax, 25% coal tar and 25% epoxy resin. The material is not susceptible to burning and is about 1/5 the cost of existing radiation protection material utilized in similar applications.

  7. Smoldering Remediation of Coal-Tar-Contaminated Soil: Pilot Field Tests of STAR.

    PubMed

    Scholes, Grant C; Gerhard, Jason I; Grant, Gavin P; Major, David W; Vidumsky, John E; Switzer, Christine; Torero, Jose L

    2015-12-15

    Self-sustaining treatment for active remediation (STAR) is an emerging, smoldering-based technology for nonaqueous-phase liquid (NAPL) remediation. This work presents the first in situ field evaluation of STAR. Pilot field tests were performed at 3.0 m (shallow test) and 7.9 m (deep test) below ground surface within distinct lithological units contaminated with coal tar at a former industrial facility. Self-sustained smoldering (i.e., after the in-well ignition heater was terminated) was demonstrated below the water table for the first time. The outward propagation of a NAPL smoldering front was mapped, and the NAPL destruction rate was quantified in real time. A total of 3700 kg of coal tar over 12 days in the shallow test and 860 kg over 11 days in the deep test was destroyed; less than 2% of total mass removed was volatilized. Self-sustaining propagation was relatively uniform radially outward in the deep test, achieving a radius of influence of 3.7 m; strong permeability contrasts and installed barriers influenced the front propagation geometry in the shallow test. Reductions in soil hydrocarbon concentrations of 99.3% and 97.3% were achieved in the shallow and deep tests, respectively. Overall, this provides the first field evaluation of STAR and demonstrates that it is effective in situ and under a variety of conditions and provides the information necessary for designing the full-scale site treatment. PMID:26523324

  8. Estrogen receptor- and aryl hydrocarbon receptor-mediated activities of a coal-tar creosote

    SciTech Connect

    Fielden, M.R.; Wu, Z.F.; Sinal, C.J.; Jury, H.H.; Bend, J.R.; Hammond, G.L.; Zacharewski, T.R.

    2000-05-01

    A coal-tar creosote was examined for estrogen receptor (ER)- and aryl hydrocarbon receptor (AhR)-mediated activity using a battery of mechanistically based assays. In vitro, creosote was found to bind to the mouse ER, bind to the human sex hormone-binding globulin, and elicit partial agonist activity in reporter gene assays in transiently transfected MCF-7 cells. Based on competitive binding to the mouse ER, creosote contains approximately 165 mg/L of estradiol-equivalents. Creosote effectively transformed the AhR in vitro and induced a Cyplal-regulated luciferase reporter gene in transiently transfected Hepa 1c1c7 cells. Based on dose-response curves, creosote contains approximately 730 mg/L of dioxin-equivalents. Creosote did not exhibit any AhR-mediated antiestrogenic activity in vitro. In vivo, creosote significantly induced liver pentoxyresorufin O-depentylation and ethoxyresorufin-O-deethylation (EROD) in a dose-dependent manner in ovariectomized (OVX) ICR mice, but did not increase uterine weight wet or vaginal cornification, due possibly to AhR-mediated antiestrogenic activity. In OVX DBA/2 mice, a strain less responsive to AhR ligands, creosote induced liver EROD to a lesser extent, but still did not show an increase in uterine wet weight or vaginal cornification. These results demonstrate that coal-tar creosote exhibits AhR- and ER-mediated activity in vitro, but its dioxinlike activity may suppress estrogenic responses in vivo.

  9. Coal-Tar-Based Parking Lot Sealcoat: An Unrecognized Source of PAH to Settled House Dust

    PubMed Central

    2010-01-01

    Despite much speculation, the principal factors controlling concentrations of polycyclic aromatic hydrocarbons (PAH) in settled house dust (SHD) have not yet been identified. In response to recent reports that dust from pavement with coal-tar-based sealcoat contains extremely high concentrations of PAH, we measured PAH in SHD from 23 apartments and in dust from their associated parking lots, one-half of which had coal-tar-based sealcoat (CT). The median concentration of total PAH (T-PAH) in dust from CT parking lots (4760 μg/g, n = 11) was 530 times higher than that from parking lots with other pavement surface types (asphalt-based sealcoat, unsealed asphalt, concrete [median 9.0 μg/g, n = 12]). T-PAH in SHD from apartments with CT parking lots (median 129 μg/g) was 25 times higher than that in SHD from apartments with parking lots with other pavement surface types (median 5.1 μg/g). Presence or absence of CT on a parking lot explained 48% of the variance in log-transformed T-PAH in SHD. Urban land-use intensity near the residence also had a significant but weaker relation to T-PAH. No other variables tested, including carpeting, frequency of vacuuming, and indoor burning, were significant. PMID:20063893

  10. Severe Coal Tar Sealcoat Runoff Toxicity to Fish Is Prevented by Bioretention Filtration.

    PubMed

    McIntyre, Jenifer K; Edmunds, Richard C; Anulacion, Bernadita F; Davis, Jay W; Incardona, John P; Stark, John D; Scholz, Nathaniel L

    2016-02-01

    Coal tar sealcoats applied to asphalt surfaces in North America, east of the Continental Divide, are enriched in petroleum-derived compounds, including polycyclic aromatic hydrocarbons (PAHs). The release of PAHs and other chemicals from sealcoat has the potential to contaminate nearby water bodies, reducing the resiliency of aquatic communities. Despite this, relatively little is known about the aquatic toxicology of sealcoat-derived contaminants. We assessed the impacts of stormwater runoff from sealcoated asphalt on juvenile coho salmon (Oncorhynchus kisutch) and embryo-larval zebrafish (Danio rerio). We furthermore evaluated the effectiveness of bioretention as a green stormwater method to remove PAHs and reduce lethal and sublethal toxicity in both species. We applied a coal tar sealcoat to conventional asphalt and collected runoff from simulated rainfall events up to 7 months postapplication. Whereas sealcoat runoff was more acutely lethal to salmon, a spectrum of cardiovascular abnormalities was consistently evident in early life stage zebrafish. Soil bioretention effectively reduced PAH concentrations by an order of magnitude, prevented mortality in juvenile salmon, and significantly reduced cardiotoxicity in zebrafish. Our findings show that inexpensive bioretention methods can markedly improve stormwater quality and protect fish health. PMID:26654684

  11. Coal-tar-based sealcoated pavement: a major PAH source to urban stream sediments.

    PubMed

    Witter, Amy E; Nguyen, Minh H; Baidar, Sunil; Sak, Peter B

    2014-02-01

    We used land-use analysis, PAH concentrations and assemblages, and multivariate statistics to identify sediment PAH sources in a small (~1303 km(2)) urbanizing watershed located in South-Central, Pennsylvania, USA. A geographic information system (GIS) was employed to quantify land-use features that may serve as PAH sources. Urban PAH concentrations were three times higher than rural levels, and were significantly and highly correlated with combined residential/commercial/industrial land use. Principal components analysis (PCA) was used to group sediments with similar PAH assemblages, and correlation analysis compared PAH sediment assemblages to common PAH sources. The strongest correlations were observed between rural sediments (n = 7) and coke-oven emissions sources (r = 0.69-0.78, n = 5), and between urban sediments (n = 22) and coal-tar-based sealcoat dust (r = 0.94, n = 47) suggesting that coal-tar-based sealcoat is an important urban PAH source in this watershed linked to residential and commercial/industrial land use. PMID:24215941

  12. Rebound of a coal tar creosote plume following partial source zone treatment with permanganate

    NASA Astrophysics Data System (ADS)

    Thomson, N. R.; Fraser, M. J.; Lamarche, C.; Barker, J. F.; Forsey, S. P.

    2008-11-01

    The long-term management of dissolved plumes originating from a coal tar creosote source is a technical challenge. For some sites stabilization of the source may be the best practical solution to decrease the contaminant mass loading to the plume and associated off-site migration. At the bench-scale, the deposition of manganese oxides, a permanganate reaction byproduct, has been shown to cause pore plugging and the formation of a manganese oxide layer adjacent to the non-aqueous phase liquid creosote which reduces post-treatment mass transfer and hence mass loading from the source. The objective of this study was to investigate the potential of partial permanganate treatment to reduce the ability of a coal tar creosote source zone to generate a multi-component plume at the pilot-scale over both the short-term (weeks to months) and the long-term (years) at a site where there is > 10 years of comprehensive synoptic plume baseline data available. A series of preliminary bench-scale experiments were conducted to support this pilot-scale investigation. The results from the bench-scale experiments indicated that if sufficient mass removal of the reactive compounds is achieved then the effective solubility, aqueous concentration and rate of mass removal of the more abundant non-reactive coal tar creosote compounds such as biphenyl and dibenzofuran can be increased. Manganese oxide formation and deposition caused an order-of-magnitude decrease in hydraulic conductivity. Approximately 125 kg of permanganate were delivered into the pilot-scale source zone over 35 days, and based on mass balance estimates < 10% of the initial reactive coal tar creosote mass in the source zone was oxidized. Mass discharge estimated at a down-gradient fence line indicated > 35% reduction for all monitored compounds except for biphenyl, dibenzofuran and fluoranthene 150 days after treatment, which is consistent with the bench-scale experimental results. Pre- and post-treatment soil core data

  13. Oil shale, tar sand, coal research, advanced exploratory process technology, jointly sponsored research

    SciTech Connect

    Not Available

    1992-01-01

    Progress made in five research programs is described. The subtasks in oil shale study include oil shale process studies and unconventional applications and markets for western oil shale.The tar sand study is on recycle oil pyrolysis and extraction (ROPE) process. Four tasks are described in coal research: underground coal gasification; coal combustion; integrated coal processing concepts; and sold waste management. Advanced exploratory process technology includes: advanced process concepts; advanced mitigation concepts; and oil and gas technology. Jointly sponsored research covers: organic and inorganic hazardous waste stabilization; CROW field demonstration with Bell Lumber and Pole; development and validation of a standard test method for sequential batch extraction fluid; PGI demonstration project; operation and evaluation of the CO[sub 2] HUFF-N-PUFF process; fly ash binder for unsurfaced road aggregates; solid state NMR analysis of Mesaverde group, Greater Green River Basin, tight gas sands; flow-loop testing of double-wall pipe for thermal applications; shallow oil production using horizontal wells with enhanced oil recovery techniques; NMR analysis of sample from the ocean drilling program; and menu driven access to the WDEQ hydrologic data management system.

  14. Evolution of dissolved organic matter during abiotic oxidation of coal tar--comparison with contaminated soils under natural attenuation.

    PubMed

    Hanser, Ogier; Biache, Coralie; Boulangé, Marine; Parant, Stéphane; Lorgeoux, Catherine; Billet, David; Michels, Raymond; Faure, Pierre

    2015-01-01

    In former coal transformation plants (coking and gas ones), the major organic contamination of soils is coal tar, mainly composed of polycyclic aromatic compounds (PACs). Air oxidation of a fresh coal tar was chosen to simulate the abiotic natural attenuation impact on PAC-contaminated soils. Water-leaching experiments were subsequently performed on fresh and oxidized coal tars to study the influence of oxidation on dissolved organic matter (DOM) quality and quantity. The characterization of the DOM was performed using a combination of molecular and spectroscopic techniques (high-performance liquid chromatography-size-exclusion chromatography (HPLC-SEC), 3D fluorescence, and gas chromatography coupled with mass spectrometry (GC-MS)) and compared with the DOM from contaminated soils sampled on the field exposed to natural attenuation for several decades. An increase in the oxygenated polycyclic aromatic compound concentrations was observed with abiotic oxidation both in the coal tar and the associated DOM. Polycyclic aromatic hydrocarbon concentrations in the leachates exceeded pure water solubility limits, suggesting that co-solvation with other soluble organic compounds occurred. Furthermore, emission excitation matrix analysis combined with synchronous fluorescence spectra interpretation and size-exclusion chromatography suggests that oxidation induced condensation reactions which were responsible for the formation of higher-molecular weight compounds and potentially mobilized by water. Thus, the current composition of the DOM in aged soils may at least partly result from (1) a depletion in lower-molecular weight compounds of the initial contamination stock and (2) an oxidative condensation leading to the formation of a higher-molecular weight fraction. Abiotic oxidation and water leaching may therefore be a significant combination contributing to the evolution of coal tar-contaminated soils under natural attenuation. PMID:25146121

  15. CARCINOGENIC EFFECTS IN A/J MICE OF PARTICULATE OF A COAL TAR PAINT USED IN POTABLE WATER SYSTEMS

    EPA Science Inventory

    Coal tar paints are among the products used as inside coatings for water pipes and storage tanks to retard corrosion in potable water supply systems. Four different formulations of these paints were tested in earlier work by this laboratory in the Ames mutagenesis and the mouse s...

  16. Possibilities of using the phenols of the light-medium tar from the high-speed pyrolysis of brown coal

    SciTech Connect

    Kazakov, E.I.; Markus, G.A.; Molchanova, I.V.; Razarenova, M.M.; Usachev, V.F.; Vilyanskaya, E.D.

    1983-01-01

    The light-medium tar from the high-speed pyrolysis of Irsha-Borodino coal contains, in addition to gasoline and oils, a large amount of valuable phenols consisting mainly of cresols and xylenols, and it may form a raw material for their production on industrial equipment already in use.

  17. Mass transfer and biodegradation of PAH compounds from coal tar. Quarterly technical report, April--June 1993

    SciTech Connect

    Ramaswami, A.; Ghoshal, S.; Luthy, R.G.

    1994-09-01

    This study, examines the role of physico-chemical mass transfer processes on the rate of biotransformation of polycyclic aromatic hydrocarbon (PAH) compounds released from non-aqueous phase liquid (NAPL) coal tar present at residual saturation within a microporous medium. A simplified coupled dissolution-degradation model is developed that describes the concurrent mass transfer and biokinetic processes occurring in the system. Model results indicate that a dimensionless Damkohler number can be utilized to distinguish between systems that are mass transfer limited, and those that are limited by biological phenomena. The Damkohler number is estimated from independent laboratory experiments that measure the rates of aqueous phase dissolution and biodegradation of naphthalene from coal tar. Experimental data for Stroudsburg coal tar imbibed within 236 {mu}m diameter silica particles yield Damkohler numbers smaller than unity, indicating, for the particular system under study, that the overall rate of biotransformation of naphthalene is not limited by the mass transfer of naphthalene from coal tar to the bulk aqueous phase. There is a need for investigation of mass transfer for larger particles and/or other PAH compounds, and study, of microbial rate-limiting phenomena including toxicity, inhibition and competitive substrate utilization.

  18. Coal-tar-based pavement sealcoat and PAHs: implications for the environment, human health, and stormwater management

    USGS Publications Warehouse

    Mahler, Barbara J.; Van Metre, Peter C.; Crane, Judy L.; Watts, Alison W.; Scoggins, Mateo; Williams, E. Spencer

    2012-01-01

    Coal-tar-based sealcoat products, widely used in the central and eastern U.S. on parking lots, driveways, and even playgrounds, are typically 20-35% coal-tar pitch, a known human carcinogen that contains about 200 polycyclic aromatic hydrocarbon (PAH) compounds. Research continues to identify environmental compartments—including stormwater runoff, lake sediment, soil, house dust, and most recently, air—contaminated by PAHs from coal-tar-based sealcoat and to demonstrate potential risks to biological communities and human health. In many cases, the levels of contamination associated with sealed pavement are striking relative to levels near unsealed pavement: PAH concentrations in air over pavement with freshly applied coal-tar-based sealcoat, for example, were hundreds to thousands of times higher than those in air over unsealed pavement. Even a small amount of sealcoated pavement can be the dominant source of PAHs to sediment in stormwater-retention ponds; proper disposal of such PAH-contaminated sediment can be extremely costly. Several local governments, the District of Columbia, and the State of Washington have banned use of these products, and several national and regional hardware and home-improvement retailers have voluntarily ceased selling them.

  19. Coal-Tar-Based Pavement Sealcoat and PAHs: Implications for the Environment, Human Health, and Stormwater Management

    PubMed Central

    2012-01-01

    Coal-tar-based sealcoat products, widely used in the central and eastern U.S. on parking lots, driveways, and even playgrounds, are typically 20−35% coal-tar pitch, a known human carcinogen that contains about 200 polycyclic aromatic hydrocarbon (PAH) compounds. Research continues to identify environmental compartments—including stormwater runoff, lake sediment, soil, house dust, and most recently, air—contaminated by PAHs from coal-tar-based sealcoat and to demonstrate potential risks to biological communities and human health. In many cases, the levels of contamination associated with sealed pavement are striking relative to levels near unsealed pavement: PAH concentrations in air over pavement with freshly applied coal-tar-based sealcoat, for example, were hundreds to thousands of times higher than those in air over unsealed pavement. Even a small amount of sealcoated pavement can be the dominant source of PAHs to sediment in stormwater-retention ponds; proper disposal of such PAH-contaminated sediment can be extremely costly. Several local governments, the District of Columbia, and the State of Washington have banned use of these products, and several national and regional hardware and home-improvement retailers have voluntarily ceased selling them. PMID:22296333

  20. Meta-analysis of lung cancer in asphalt roofing and paving workers with external adjustment for confounding by coal tar

    SciTech Connect

    Fayerweather, W.E.

    2007-07-01

    The study's objectives were to update Partanen's and Boffetta's 1994 meta-analysis of lung cancer among roofing and paving asphalt workers and explore the role of coal tar in explaining the statistical heterogeneity among these studies. Information retrieval strategies and eligibility criteria were defined for identifying the epidemiologic studies to be included in the analysis. The relative risk ratio (RR) for lung cancer was selected as the effect measure of interest. Coal tar bias factors were developed and used to externally adjust each eligible study's published RR for confounding by coal tar. The meta-Relative Risk (meta-RR) and its variance were estimated by general variance-based methods. Heterogeneity of the RRs was assessed by heterogeneity chi-square and I{sup 2} tests. The results from this update were similar to those in Partanen's and Boffetta's original meta-analysis. Although the meta-RRs for the roofers and the pavers were no longer statistically significantly different from one another, significant heterogeneity remained within each of the coal tar-adjusted sectors. Meta-analysis of non-experimental epidemiologic studies is subject to significant uncertainties as is externally correcting studies for confounding. Given these uncertainties, the specific quantitative estimates in this (or any similar) analysis must be viewed with caution. Nevertheless, this analysis provides support for the hypothesis proposed by several major reviewers that confounding by coal tar-related PAH exposures may explain most or all of the lung cancer risks found in the epidemiologic literature on asphalt roofing and paving workers.

  1. Partitioning studies of coal-tar constitutents in a two-phase contaminated ground-water system

    SciTech Connect

    Rostad, C.E.; Pereira, W.E.; Hult, M.F.

    1985-01-01

    Organic compounds derived from coal-tar wastes in a contaminated aquifer in St. Louis Park, Minnesota, were identified, and their partition coefficients between the tar phase and aqueous phase were determined and compared with the corresponding n-octanol/water partition coefficients. Coal tar contains numerous polycyclic aromatic compounds, many of which are suspected carcinogens or mutagens. Groundwater contamination by these toxic compounds may pose an environmental health hazard in nearby public water-supply wells. Fluid samples from this aquifer developed two phases upon settling: an upper aqueous phase, and a lower oily-tar phase. After separating the phases, polycyclic aromatic compounds in each phase were isolated using complexation with N-methyl-2-pyrrolidone and identified by fused-silica capillary gas chromatography/mass spectrometry. Thirty-one of the polycyclic aromatic compounds were chosen for further study from four different classes: 12 polycyclic aromatic hydrocarbons, 10 nitrogen heterocycles, 5 sulfur heterocycles, and 4 oxygen heterocycles. Within each compounds class, the tar/water partition coefficients of these compounds were reasonable comparable with the respective n-octanol/water partition coefficient.

  2. Partitioning studies of coal-tar constituents in a two-phase contaminated ground-water system

    USGS Publications Warehouse

    Rostad, C.E.; Pereira, W.E.; Hult, M.F.

    1985-01-01

    Organic compounds derived from coal-tar wastes in a contaminated aquifer in St. Louis Park, Minnesota, were identified, and their partition coefficients between the tar phase and aqueous phase were determined and compared with the corresponding n-octanol/water partition coefficients. Coal tar contains numerous polycyclic aromatic compounds, many of which are suspected carcinogens or mutagens. Groundwater contamination by these toxic compounds may pose an environmental health hazard in nearby public water-supply wells. Fluid samples from this aquifer developed two phases upon settling: an upper aqueous phase, and a lower oily-tar phase. After separating the phases, polycyclic aromatic compounds in each phase were isolated using complexation with N-methyl-2-pyrrolidone and identified by fused-silica capillary gas chromatography/mass spectrometry. Thirty-one of the polycyclic aromatic compounds were chosen for further study from four different classes: 12 polycyclic aromatic hydrocarbons, 10 nitrogen heterocycles, 5 sulfur heterocycles, and 4 oxygen heterocycles. Within each compound class, the tar/water partition coefficients of these compounds were reasonably comparable with the respective n-octanol/water partition coefficient.

  3. Natural selection of PAH-degrading bacterial guilds at coal-tar disposal sites

    SciTech Connect

    Ghiorse, W.C.; Herrick, J.B.; Sandoli, R.L.; Madsen, E.L.

    1995-06-01

    Microbial activity patterns at buried coal-tar disposal sites have been under investigation for several years to determine the response of naturally occurring microflora to polycyclic aromatic hydrocarbons (PAHs) at the sites. At one site in upstate New York, data have shown enrichment of PAH-degrading bacteria in subsurface contaminated zones but not in uncontaminated zones. Similar work at a Midwestern site showed that the same trends existed in a heterogeneous disposal site except that a borehole outside the plume showed some PAH-mineralization activity. Polymerase chain reaction amplification of DNA extracted from sediment samples from the New York site indicated the presence of naphthalene metabolism genes nahAc and nahR, similar to those found on the NAH7 plasmid of Pseudomonas putida G7. Significant sequence polymorphism was observed in amplified nahAc products, indicating that divergent homologs of nahAc were present in the native community. Protozoan numbers were elevated in sediment samples displaying relatively high PAH-degrading activity, suggesting that a food chain was established based on PAH-degrading bacteria. Removal of the coal-tar source at the site occurred in 1991. In 1992, sampling of three key borehole stations revealed that mixing and backfilling operations had introduced soil microorganisms into the source area and introduced 14C-PAH-mineralization activity into the previously inactive pristine area. Thus removal of the source of the contaminants and restoration at the site have altered the microbial activity patterns outside the contaminant plume as well as in the source area. 15 refs., 3 figs.

  4. The nature and molecular basis of cutaneous photosensitivity reactions to psoralens and coal tar

    SciTech Connect

    Pathak, M.A.; Joshi, P.C.

    1983-06-01

    The basic aspects of cutaneous photosensitization reactions and the mode of therapeutic effectiveness of psoralens and coal tar, the two groups of photosensitizing agents used extensively in the photochemotherapy of psoriasis, have been reviewed. Psoralen-induced skin photosensitization and the therapeutic action of psoralens involve two distinct types of reactions, and these two reactions occur independently of each other and concurrently when the psoralen-treated skin (oral or topical) is exposed to 320 to 400 nm of radiation. The first, type I, is an oxygen-independent reaction and primarily involves photoreaction with DNA; the second, type II, is a sensitized reaction dependent on oxygen and involves the formation of singlet oxygen (1O2). The photoreactive form of psoralen is its triplet state, and the sites of reaction are (1) the cell membrane of the epidermal, dermal, and endothelial cells; (2) the cytoplasmic constituents, such as enzymes, RNA, lysosomes, etc.; (3) the cell nuclei (DNA and chromatin); and (4) the sensitized production of 1O2, which is responsible for cell-membrane damage and vasodilation. The major damage would be initiated by a type I reaction and would be seen in the form of nuclear damage to DNA resulting from the interaction of psoralen with DNA and to a lesser extent with RNA. The skin photosensitization response (erythema, edema, membrane damage, etc.) would result from a type II reaction involving the generation of 1O2. Crude coal tar (CCT), widely used in the Goeckerman therapy for psoriasis, also produces type I and type II reactions. The therapeutic and photosensitizing actions of CCT are due to (1) the photoconjugation of the photoreactive ingredients of CCT with DNA, causing interstrand cross-links; and (2) the production of 1O2. CCT is an efficient producer of 1O2, more so than 8-methoxypsoralen, and is responsible for cell-membrane damage and cellular edema.

  5. [Experimental and clinical demonstration of the antiproliferative effect of a highly purified coal tar fraction in a special gel vehicle].

    PubMed

    Bernd, A; Wehrenberg, O; Hevert, F; Holzmann, H

    1988-04-01

    In this study a combination of clinical and experimental investigations demonstrates the antiproliferative effect of the coal tar-containing preparation Berniter. From a concentration of 70 micrograms/ml onwards (= 0.35 micrograms coal tar/ml) Berniter inhibits DNA synthesis of transformed human keratinocytes in vitro. The growth inhibiting effect is reversible up to the ED50 concentration (257 micrograms Berniter/ml = 1.3 micrograms coal tar/ml). The tar-free vehicle has no identifiable effect on the proliferation of the cells at a concentration of 260 micrograms/ml. However, at higher concentrations (ED50 = 1023 micrograms/ml) the vehicle also inhibits cell growth, this inhibition being irreversible. The effect of Berniter and the tar-free vehicle on amino acid metabolism corresponds with the reduced growth rate. The ED50 concentrations (331 micrograms/ml for Berniter and 1445 micrograms/ml for the tar-free vehicle) are higher than those in the investigation of the proliferation. The clinical trial was performed in two groups of 12 and 11 patients, respectively, suffering from Psoriasis capillitii. After 3 days' topical treatment of both groups with salicylic acid for scaling, one group was treated for 4 weeks with betamethasone-17-valerate (in the following briefly called Bet-17-v), as a commercial lotion. The other group received Bet-17-v initially for 3 days and was then treated for 4 weeks with Berniter. The 4 parameters used for evaluation (erythema, scaling, infiltration and itching) showed a more significant improvement in the Berniter group than in the Bet-17-v group. Subjectively, treatment with Berniter was assessed to be preferable.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3401273

  6. Vapor pressures and heats of vaporization of primary coal tars. Quarterly technical progress report, 1 October 1993--31 December 1993

    SciTech Connect

    Suuberg, E.M.

    1993-12-31

    The vapor pressure correlations that exist at present for coal tars are very crude and they are not considered reliable to even an order of magnitude when applied to tars. Sophisticated general correlative approaches are slowly being developed, based upon group contribution methods, or based upon some key functional features of the molecules. These are as yet difficult to apply to coal tars. The detailed group contribution methods, in which fairly precise structural information is needed, do not lend themselves well for application to very complex, poorly characterized coal tars. The methods based upon more global types of characterizations have not yet dealt much with the question of oxygenated functional groups. In short, only very limited correlations exist, and these are not considered reliable to even an order of magnitude when applied to tars. The present project seeks to address this important gap in the near term by direct measurement of vapor pressures of coal tar fractions, by application of well-established techniques and modifications thereof. The principal objectives of the program are to: (1) obtain data on the vapor pressures and heats of vaporization of tars from a range of ranks of coal, (2) develop correlations based on a minimum set of conveniently measurable characteristics of the tars, (3) develop equipment that would allow performing such measurements in a reliable, straightforward fashion.

  7. Using polymer solutions to enhance recovery of mobile coal tar and creosote DNAPLs.

    PubMed

    Giese, Steven W; Powers, Susan E

    2002-09-01

    Direct pumping and enhanced recovery of coal tar and creosote dense, non-aqueous phase liquids (DNAPLs) from the subsurface have had mixed results because these DNAPLs are viscous fluids that can potentially alter aquifer wettability. To improve the inefficiencies associated with waterflooding, the research presented here considered the use of a polymer solution that can be added to the injected flood solution to increase the viscosity and decrease the velocity of the flooding solution. Results from one-dimensional, vertically oriented laboratory column experiments that evaluate the recovery of coal-derived DNAPL with both water and polymer flooding solutions are presented. The final DNAPL saturation remaining in the column was assessed in water and oil-wet systems for three viscous DNAPLs. Adding polymer to increase the aqueous solution viscosity did not have a significant impact in water-wet systems. A final DNAPL saturation of approximately 19% was achieved for both water and polymer floods. In contrast, the addition of polymer significantly improved recovery in oil-wet systems. The final saturation was over 40% in oil-wet systems after waterflooding, but approximately 19% with a polymer flushing solution. Although the final saturation produced with polymer flooding was similar between the oil- and water-wet systems, differences in the relative permeability and distribution of DNAPL in the porous matrix caused the DNAPL recovery to be much slower in the oil-wet system. PMID:12236554

  8. Migration and natural fate of a coal tar creosote plume. 2. Mass balance and biodegradation indicators

    NASA Astrophysics Data System (ADS)

    King, Mark W. G.; Barker, James F.; Devlin, John F.; Butler, Barbara J.

    1999-10-01

    A source of coal tar creosote was emplaced below the water table at CFB Borden to investigate natural attenuation processes for complex biodegradable mixtures. A mass balance indicated that ongoing transformation occurred for seven study compounds. Phenol migrated as a discrete slug plume and almost completely disappeared after 2 years, after being completely leached from the source early in the study. The m-xylene plume migrated outward to a maximum distance at approximately 2 years, and then receded back towards the source as the rate of mass flux out of the source decreased to below the overall rate of plume transformation. Carbazole showed similar behaviour, although the reversal in plume development occurred more slowly. The dibenzofuran plume remained relatively constant in extent and mass over the last 2 years of monitoring, despite constant source input over this period, providing evidence that the dibenzofuran plume was at steady state. Meanwhile, the naphthalene and 1-methylnaphthalene plumes continued to advance and increase in mass over the observation period, although at a decreasing rate. The phenanthrene plume was also subject to transformation, although measurement of the rate was less conclusive due to the higher proportion of sorbed mass for this compound. Three lines of evidence are presented to evaluate whether the observed plume mass loss was due to microbial biodegradation. Measurement of redox-sensitive parameters in the vicinity of the plume showed the types of changes that would be expected to occur due to plume biodegradation: dissolved oxygen and SO 42- decreased in groundwater within the plume while significant increases were noted for Fe 2+, Mn 2+ and methane. Further evidence that plume mass loss was microbially-mediated was provided by the accumulation of aromatic acids within the plume. Measurements of phospholipid fatty acids (PLFA) in aquifer material indicated that microbial biomass and turnover rate were greater within the plume

  9. [Effect of various kinds of tar and tar concentrations on anthralin erythema].

    PubMed

    Wemmer, U; Schulze, H J; Mahrle, G; Steigleder, G K

    1986-06-15

    The effect of tar on anthralin-induced erythema was epicutaneously tested in ten patients. 3%, 5%, or 10% crude coal tar or coal tar solution was added to vaseline containing anthralin. A 5% or 10% tar preparation significantly suppressed the anthralin erythema induced by 0.5 to 1.0% anthralin having been applied for 24 hrs. In these concentrations, coal tar solution was at least as effective as coal tar itself. PMID:3751210

  10. Coal-gasification and tar-conversion reactions over calcium oxide. Annual progress report, August 1, 1981-October 31, 1982

    SciTech Connect

    Longwell, J.P.; Chang, C.S.; Peters, W.A.

    1983-01-01

    This research focusses on low temperature (723-1123 K) effects of calcium oxide on coal gasification and coal pyrolysis. The general objective of the present research is to investigate the chemistry and global kinetics of thermal reactions of freshly-formed tars in the presence of calcium oxide, and thereby assess the potential application for achieving improved overall gas yields and product quality in practical processes. Construction and debugging of the experimental system, designed to achieve this goal, have been completed. Preliminary runs showed that the system can be operated satisfactorily according to the design specifications. The extent of fresh tar cracking can be controlled by independently adjusting the major operating variables, such as reactor temperature, contact time (with active calcium oxide), and system pressure. The collection systems and the analytical techniques employed for characterizing the pyrolysis products have been identified. A standard procedure for reproducibly generating packed beds of active calcium oxide that exhibited minimal variation in stone surface area along their axis is under development. A 2-step calcination protocol shows promise for achieving this goal for well-defined experiments. Preliminary results of coal volatile generation and cracking experiments indicate that calcium oxide can drastically reduce the absolute yield of tars and significantly increase the production and yields of methane and ethylene gases. Overall material balances also appear to be satisfactory.

  11. Allergies

    MedlinePlus

    ... cause an anaphylactic reaction in some people. Airborne particles. Often called environmental allergens, these are the most common allergens. Examples of airborne particles that can cause allergies are dust mites (tiny ...

  12. Allergies

    MedlinePlus Videos and Cool Tools

    ... are white blood cells containing the chemical histamine. As more antibodies are produced, they cause the mast ... to release histamine. Histamine then produces allergy symptoms. A stuffy and runny nose, sneezing and watery eyes ...

  13. Allergy

    MedlinePlus

    ... not bother most other people. People who have allergies often are sensitive to more than one thing. Substances that often cause reactions are Pollen Dust mites Mold spores Pet dander Food Insect ...

  14. Allergies

    MedlinePlus

    ... make certain medical conditions, such as sinus problems, eczema , and asthma , worse. ... by allergies (such as asthma, hay fever, and eczema) may need other treatments. Medications that can be ...

  15. Coal-tar-based parking lot sealcoat: An unrecognized source of PAH to settled house dust

    USGS Publications Warehouse

    Mahler, B.J.; Van Metre, P.C.; Wilson, J.T.; Musgrove, M.; Burbank, T.L.; Ennis, T.E.; Bashara, T.J.

    2010-01-01

    Despite much speculation, the principal factors controlling concentrations of polycyclic aromatic hydrocarbons (PAH) in settled house dust (SHD) have not yet been identified. In response to recent reports that dust from pavement with coaltar-based sealcoat contains extremely high concentrations of PAH, we measured PAH in SHD from 23 apartments and in dust from their associated parking lots, one-half of which had coal-tar-based sealcoat (CT). The median concentration of total PAH (T-PAH) in dust from CT parking lots (4760 ??g/g, n = 11) was 530 times higher than that from parking lots with other pavement surface types (asphalt-based sealcoat, unsealed asphalt, concrete [median 9.0 ??g/g, n = 12]). T-PAH in SHD from apartments with CT parking lots (median 129 ??g/g) was 25 times higher than that in SHD from apartments with parking lots with other pavement surface types (median 5.1 ??g/g). Presence or absence of CT on a parking lot explained 48% of the variance in log-transformed T-PAH in SHD. Urban land-use intensity near the residence also had a significant but weaker relation to T-PAH. No other variables tested, including carpeting, frequency of vacuuming, and indoor burning, were significant. ?? 2010 American Chemical Society.

  16. Vapor pressures and heats of vaporization of primary coal tars. Quarterly technical progress report, 1 July 1993--30 September 1993

    SciTech Connect

    Suuberg, E.M.; Oja, V.; Lilly, W.D.

    1993-12-31

    There is significant current interest in general area of coal pyrolysis, particularly with respect to comprehensive models of this complicated phenomenon. This interest derives from the central role of pyrolysis in all thermally driven coal conversion processes -- gasification, combustion, liquefaction, mild gasification, or thermal benefication. There remain several key data needs in these application areas. Among them is a need for more reliable correlation for prediction of vapor pressure of heavy, primary coal tars. Such information is important in design of all coal conversion processes, in which the volatility of tarry products is of major concern. Only very limited correlations exist, and these are not considered reliable to even an order of magnitude when applied to tars. The present project seeks to address this important gap in the near term by direct measurement of vapor pressures of coal tar fractions, by application of well-established techniques and modifications thereof. The principal objectives of the program are to: (1) obtain data on the vapor pressures and heats of vaporization of tars from a range of ranks of coal, (2) develop correlations based on a minimum set of conveniently measurable characteristics of the tars, (3) develop equipment that would allow performing such measurements in a reliable, straightforward fashion. Results of the literature survey are compiled. The experimental tasks have been concerned with setup and calibration.

  17. Response of microbial activities and diversity to PAHs contamination at coal tar contaminated land

    NASA Astrophysics Data System (ADS)

    Zhao, Xiaohui; Sun, Yujiao; Ding, Aizhong; Zhang, Dan; Zhang, Dayi

    2015-04-01

    Coal tar is one of the most hazardous and concerned organic pollutants and the main hazards are polycyclic aromatic hydrocarbons (PAHs). The indigenous microorganisms in soils are capable to degrade PAHs, with essential roles in biochemical process for PAHs natural attenuation. This study investigated 48 soil samples (from 8 depths of 6 boreholes) in Beijing coking and chemistry plant (China) and revealed the correlation between PAHs contamination, soil enzyme activities and microbial community structure, by 16S rRNA denaturing gradient gel electrophoresis (DGGE). At the site, the key contaminants were identified as naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene and anthracene, and the total PAHs concentration ranged from 0.1 to 923.9 mg/kg dry soil. The total PAHs contamination level was positively correlated (p<0.05) with the bacteria count (0.9×107-14.2×107 CFU/mL), catalase activities (0.554-6.230 mL 0.02 M KMnO4/g•h) and dehydrogenase activities (1.9-30.4 TF μg/g•h soil), showing the significant response of microbial population and degrading functions to the organic contamination in soils. The PAHs contamination stimulated the PAHs degrading microbes and promoted their biochemical roles in situ. The positive relationship between bacteria count and dehydrogenase activities (p<0.05) suggested the dominancy of PAHs degrading bacteria in the microbial community. More interestingly, the microbial community deterioration was uncovered via the decline of microbial biodiversity (richness from 16S rRNA DGGE) against total PAHs concentration (p<0.05). Our research described the spatial profiles of PAHs contamination and soil microbial functions at the PAHs heavily contaminated sites, offering deeper understanding on the roles of indigenous microbial community in natural attenuation process.

  18. PAH concentrations in lake sediment decline following ban on coal-tar-based pavement sealants in Austin, Texas

    USGS Publications Warehouse

    Van Metre, Peter C.; Mahler, Barbara J.

    2013-01-01

    Recent studies have concluded that coal-tar-based pavement sealants are a major source of polycyclic aromatic hydrocarbons (PAHs) in urban settings in large parts of the United States. In 2006, Austin, TX, became the first jurisdiction in the U.S. to ban the use of coal-tar sealants. We evaluated the effect of Austin’s ban by analyzing PAHs in sediment cores and bottom-sediment samples collected in 1998, 2000, 2001, 2012, and 2014 from Lady Bird Lake, the principal receiving water body for Austin urban runoff. The sum concentration of the 16 EPA Priority Pollutant PAHs (∑PAH16) in dated core intervals and surficial bottom-sediment samples collected from sites in the lower lake declined about 44% from 1998–2005 to 2006–2014 (means of 7980 and 4500 μg kg–1, respectively), and by 2012–2014, the decline was about 58% (mean of 3320 μg kg–1). Concentrations of ∑PAH16 in bottom sediment from two of three mid-lake sites decreased by about 71 and 35% from 2001 to 2014. Concentrations at a third site increased by about 14% from 2001 to 2014. The decreases since 2006 reverse a 40-year (1959–1998) upward trend. Despite declines in PAH concentrations, PAH profiles and source-receptor modeling results indicate that coal-tar sealants remain the largest PAH source to the lake, implying that PAH concentrations likely will continue to decline as stocks of previously applied sealant gradually become depleted.

  19. Pyridine and other coal tar constituents as inhibitors of potato polyphenol oxidase: A non-animal model for neurochemical studies

    SciTech Connect

    Henderson, H.M.; Eskin, N.A.M.; Pinsky, C.; Bose, R.; Ashique, A.M. )

    1992-01-01

    Potato polyphenol oxidase activity was strongly and noncompetitively inhibited by the 'Perov mixture' of coal tar components and by pyridine alone, while phenol competitively inhibited the enzyme. These two inhibitors are structural components of the parkinsonogenic neurotoxin N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). By extension, dopamine and neuromelanin synthesis in the brain may be influenced by the inhibitory effects of such compounds upon the copper-dependent steps of tyrosine metabolism. The non-animal model used in this study may represent an alternative to the use of animal tissues in neurodegenerative disease research.

  20. Pyridine and other coal tar constituents as inhibitors of potato polyphenol oxidase: a non-animal model for neurochemical studies.

    PubMed

    Henderson, H M; Eskin, N A; Pinsky, C; Bose, R; Ashique, A M

    1992-01-01

    Potato polyphenol oxidase activity was strongly and noncompetitively inhibited by the "Perov mixture" of coal tar components and by pyridine alone, while phenol competitively inhibited the enzyme. These two inhibitors are structural components of the parkinsonogenic neurotoxin N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). By extension, dopamine and neuromelanin synthesis in the brain may be influenced by the inhibitory effects of such compounds upon the copper-dependent steps of tyrosine metabolism. The non-animal model used in this study may represent an alternative to the use of animal tissues in neurodegenerative disease research. PMID:1435072

  1. Airborne concentrations, skin contamination, and urinary metabolite excretion of polycyclic aromatic hydrocarbons among paving workers exposed to coal tar derived road tars

    SciTech Connect

    Jongeneelen, F.J.; Scheepers, P.T.; Groenendijk, A.; Van Aerts, L.A.; Anzion, R.B.; Bos, R.P.; Veenstra, S.J.

    1988-12-01

    The exposure of surface dressing workers to polycyclic aromatic hydrocarbons (PAH) was studied. Four different paving sites, at which coal tar-containing binders were applied, were selected as work sites with high exposure levels of PAH. Breathing zone airborne particulates, contamination of the skin with PAH, and 1-hydroxypyrene in urine of the workers involved in chip sealing were determined. Substantial concentrations of cyclohexane-soluble airborne particulate matter were found (GM = 0.2 mg/m3, n = 28). Skin contamination was determined using two different methods: with exposure pads and by hand washing. Pads were mounted on several parts of the body: wrist, elbow, neck, shoulder, and ankle. The pads located on the wrist appeared to be the most contaminated (pyrene: GM = 22 ng/1.77 cm2, n = 40). The end-of-shift hand washing showed that the hands of the workers were contaminated with PAH (pyrene: GM = 70 micrograms, n = 35). Preshift hand washing showed far lower, but detectable, quantities of PAH on workers' hands (pyrene: GM = 5 micrograms, n = 35). Enhanced levels of urinary 1-hydroxypyrene among the workers were found. The highest levels were found in the end-of-shift urine samples. Correlations between the pyrene exposure variables were studied. Significant positive correlations were found between pyrene on the wrist pad versus end-of-shift urinary 1-hydroxypyrene; between pyrene on the hands versus end-of-shift urinary 1-hydroxypyrene; and between the two different skin contamination variables.

  2. PAH Concentrations Decline Following 2006 Ban on Coal-Tar-Based Pavement Sealants in Austin, Texas

    NASA Astrophysics Data System (ADS)

    Van Metre, P. C.; Mahler, B. J.

    2013-12-01

    Recent studies have concluded that coal-tar-based pavement sealants (CT sealants) are a major source of polycyclic aromatic hydrocarbons (PAHs) in non-industrial urban settings in the United States. In 2006, Austin, TX, became the first jurisdiction in the U.S. to ban the use of CT sealants. We evaluated PAH concentrations following the ban by analyzing sediment cores collected from Lady Bird Lake in 2012; Lady Bird Lake impounds the Colorado River in central Austin and receives runoff from much of the greater Austin area. The mean sum concentration of the 16 U.S. Environmental Protection Agency Priority Pollutant PAHs (∑PAH16) in one of two 2012 sediment cores analyzed for PAHs declined 75% from before 2006 (mean of 4 samples=8,090 μg kg-1) to 2012 (mean of 2 samples=2,030 μg kg-1), reversing a 40-year (1959-1999) upward trend in PAH concentrations that was previously documented. The downward trend in PAH concentrations in the seven uppermost 1 cm sampling intervals in the first 2012 core was statistically significant (r=0.93, p-value=0.002). Post-2008 PAH trends in the second 2012 core were similar (significant downward trend in the six uppermost 1 cm sampling intervals and mean 2012 ∑PAH16 of 2,390 μg kg-1); however, pre-2007 sediment did not appear to have been preserved in this core likely because of the effects of flooding on sediment deposition and mixing at this site--the largest flood on the Colorado River in Austin in 20 years was in 2007. On the basis of a comparison of lake-sediment PAH profiles to 22 PAH source profiles, the PAH loading to lake sediment continues to be dominated by CT sealants. The continued dominance of proportional PAH loading by CT sealants in spite of decreased concentrations since 2006 might be because legacy CT sealant and contaminated soils and sediments continue to yield PAHs to runoff. A previous study using source-receptor modeling concluded that CT sealants were the largest PAH source to 40 urban lakes studied in the

  3. Influence of coal-tar sealcoat and other carbonaceous materials on polycyclic aromatic hydrocarbon loading in an urban watershed.

    PubMed

    Yang, Yaning; Van Metre, Peter C; Mahler, Barbara J; Wilson, Jennifer T; Ligouis, Bertrand; Razzaque, M D Muhit; Schaeffer, David J; Werth, Charles J

    2010-02-15

    Carbonaceous material (CM) particles are the principal vectors transporting polycyclic aromatic hydrocarbons (PAHs) into urban waters via runoff; however, characteristics of CM particles in urban watersheds and their relative contributions to PAH contamination remain unclear. Our objectives were to identify the sources and distribution of CM particles in an urban watershed and to determine the types of CMs that were the dominant sources of PAHs in the lake and stream sediments. Samples of soils, parking lot and street dust, and streambed and lake sediment were collected from the Lake Como watershed in Fort Worth, Texas. Characteristics of CM particles determined by organic petrography and a significant correlation between PAH concentrations and organic carbon in coal tar, asphalt, and soot indicate that these three CM particle types are the major sources and carriers of PAHs in the watershed. Estimates of the distribution of PAHs in CM particles indicate that coal-tar pitch, used in some pavement sealcoats, is a dominant source of PAHs in the watershed, and contributes as much as 99% of the PAHs in sealed parking lot dust, 92% in unsealed parking lot dust, 88% in commercial area soil, 71% in streambed sediment, and 84% in surficial lake sediment. PMID:20102236

  4. Fabrication method and microstructural characteristics of coal-tar-pitch-based 2D carbon/carbon composites

    NASA Astrophysics Data System (ADS)

    Esmaeeli, Mohammad; Khosravi, Hamed; Mirhabibi, Alireza

    2015-02-01

    The lignin-cellulosic texture of wood was used to produce two-dimensional (2D) carbon/carbon (C/C) composites using coal tar pitch. Ash content tests were conducted to select two samples among the different kinds of woods present in Iran, including walnut, white poplar, cherry, willow, buttonwood, apricots, berry, and blue wood. Walnut and white poplar with ash contents of 1.994wt% and 0.351wt%, respectively, were selected. The behavior of these woods during pyrolysis was investigated by differential thermal analysis (DTA) and thermo gravimetric (TG) analysis. The bulk density and open porosity were measured after carbonization and densification. The microstructural characteristics of samples were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared (FT-IR) spectroscopy. The results indicate that the density of both the walnut and white poplar is increased, and the open porosity is decreased with the increasing number of carbonization cycles. The XRD patterns of the wood charcoal change gradually with increasing pyrolysis temperature, possibly as a result of the ultra-structural changes in the charcoal or the presence of carbonized coal tar pitch in the composite's body.

  5. Preliminary evaluation of ground-water contamination by coal-tar derivatives, St. Louis Park area, Minnesota

    USGS Publications Warehouse

    Hult, Marc F.; Schoenberg, Michael

    1981-01-01

    Operation of a coal-tar distillation and wood preserving plant for 1918-72 in St. Louis Park, Minnesota, resulted in ground-water contamination. This report presents the results of the first year (1979) of an ongoing study. By 1932, water in the Prairie du Chien-Jordan aquifer, the region 's major source of ground water, was contaminated 3,500 feet from the plant. The hydraulic characteristics of the Prairie du Chien-Jordan aquifer , its long contamination history, and fluctuating pumpage combine to creat a complex distribution of coal-tar derivatives observed in the aquifer. The Prairie du Chien-Jordan aquifer underlies the area at depths of 250 to 500 feet and is overlain by two bedrock aquifers (Platteville and St. Peter), two confining beds (Glenwood and basal part of St. Peter), and 70 to 100 feet of glacial drift. Multiaquifer wells in the area have permitted contaminated water from near-surface aquifers to flow downward into the Prairie du Chien-Jordan aquifer. Flow rates of 20 to 150 gallons per minute from the shallower aquifers into the Prairie du Chien-Jordan aquifer were observed in five wells. In the drift, a hydrocarbon fluid phase is moving vertically downward relative to the aqueous phase. Dissolved constituents in the drift and Platteville aquifer, the uppermost bedrock unit over most of the area, have moved at least 4,000 feet. Low-molecular-weight compounds are moving preferentially through the drift and Platteville aquifer system. (USGS)

  6. Influence of coal-tar sealcoat and other carbonaceous materials on polycyclic aromatic hydrocarbon loading in an urban watershed

    USGS Publications Warehouse

    Yang, Y.; Van Metre, P.C.; Mahler, B.J.; Wilson, J.T.; Ligouis, B.; Razzaque, M.; Schaeffer, D.J.; Werth, C.J.

    2010-01-01

    Carbonaceous material (CM) particles are the principal vectors transporting polycyclic aromatic hydrocarbons (PAHs) into urban waters via runoff; however, characteristics of CM particles in urban watersheds and their relative contributions to PAH contamination remain unclear. Our objectives were to identify the sources and distribution of CM particles in an urban watershed and to determine the types of CMs that were the dominant sources of PAHs in the lake and stream sediments. Samples of soils, parking lot and street dust, and streambed and lake sediment were collected from the Lake Como watershed in Fort Worth, Texas. Characteristics of CM particles determined by organic petrography and a significant correlation between PAH concentrations and organic carbon in coal tar, asphalt, and soot indicate that these three CM particle types are the major sources and carriers of PAHs in the watershed. Estimates of the distribution of PAHs in CM particles indicate that coal-tar pitch, usedinsomepavementsealcoats, isadominant source of PAHs in the watershed, and contributes as much as 99% of the PAHs in sealed parking lot dust, 92% in unsealed parking lot dust, 88% in commercial area soil, 71% in streambed sediment, and 84% in surficial lake sediment. ?? 2010 American Chemical Society.

  7. Concentrations of polycyclic aromatic hydrocarbons (PAHs) and azaarenes in runoff from coal-tar- and asphalt-sealcoated pavement

    USGS Publications Warehouse

    Mahler, Barbara J.; Van Metre, Peter C.; Foreman, William T.

    2014-01-01

    Coal-tar-based sealcoat, used extensively on parking lots and driveways in North America, is a potent source of PAHs. We investigated how concentrations and assemblages of PAHs and azaarenes in runoff from pavement newly sealed with coal-tar-based (CT) or asphalt-based (AS) sealcoat changed over time. Samples of simulated runoff were collected from pavement 5 h to 111 d following application of AS or CT sealcoat. Concentrations of the sum of 16 PAHs (median concentrations of 328 and 35 μg/L for CT and AS runoff, respectively) in runoff varied relatively little, but rapid decreases in concentrations of azaarenes and low molecular weight PAHs were offset by increases in high molecular weight PAHs. The results demonstrate that runoff from CT-sealcoated pavement, in particular, continues to contain elevated concentrations of PAHs long after a 24-h curing time, with implications for the fate, transport, and ecotoxicological effects of contaminants in runoff from CT-sealcoated pavement.

  8. Mineralization of PAHs in coal-tar impacted aquifer sediments and associated microbial community structure investigated with FISH.

    PubMed

    Rogers, Shane W; Ong, Say Kee; Moorman, Thomas B

    2007-11-01

    The microbial community structure and mineralization of polycyclic aromatic hydrocarbons (PAHs) in a coal-tar contaminated aquifer were investigated spatially using fluorescence in situ hybridization (FISH) and in laboratory-scale incubations of the aquifer sediments. DAPI-detected microbial populations in the contaminated sediments were three orders of magnitude greater than nearby uncontaminated sediments, suggesting growth on coal-tar constituents in situ. Actinobacteria, beta- and gamma-Proteobacteria, and Flavobacteria dominated the in situ aerobic (>1 mg l(-1) dissolved oxygen) microbial community, whereas sulfate-reducing bacteria comprised 37% of the microbial community in the sulfidogenic region of the aquifer. Rapid mineralization of naphthalene and phenanthrene were observed in aerobic laboratory microcosms and resulted in significant enrichment of beta- and gamma-Proteobacteria potentially explaining their elevated presence in situ. Firmicutes, Flavobacteria, alpha-Proteobacteria, and Actinobacteria were also enriched in the mineralization assays, but to a lesser degree. Nitrate- and sulfate-limited mineralization of naphthalene in laboratory microcosms occurred to a small degree in aquifer sediments from locations where groundwater chemistry indicated nitrate- and sulfate-reduction, respectively. Some iron-limited mineralization of naphthalene and phenanthrene was also observed in sediments originating near groundwater measurements of elevated ferrous iron. The results of this study suggest that FISH may be a useful tool for providing a much needed link between laboratory microcosms and groundwater measurements made in situ necessary to better demonstrate the potential for natural attenuation at complex PAH contaminated sites. PMID:17617439

  9. Oral exposure to commercially available coal tar-based pavement sealcoat induces murine genetic damage and mutations.

    PubMed

    Long, Alexandra S; Watson, Margaret; Arlt, Volker M; White, Paul A

    2016-08-01

    Coal tar (CT) is a thick black liquid produced as a by-product of coal carbonization to produce coke or manufactured gas. It is comprised a complex mixture of polycyclic aromatic compounds, including a wide range of polycyclic aromatic hydrocarbons (PAHs), many of which are genotoxic and carcinogenic. CT is used in some pavement sealants (also known as sealcoat), which are applied to pavement in order to seal and beautify the surface. Human exposure is known to occur not only during application, but also as a result of the weathering process, as elevated levels of PAHs have been found in settled house dust in residences adjacent to CT-sealed surfaces. In this study we examined the genotoxicity of an extract of a commercially available CT-based sealcoat in the transgenic Muta™Mouse model. Mice were orally exposed to 3 doses of sealcoat extract daily for 28 days. We evaluated genotoxicity by examining: (1) stable DNA adducts and (2) lacZ mutations in bone marrow, liver, lung, small intestine, and glandular stomach, as well as (3) micronucleated red blood cells. Significant increases were seen for each endpoint and in all tissues. The potency of the response differed across tissues, with the highest frequency of adducts occurring in liver and lung, and the highest frequency of mutations occurring in small intestine. The results of this study are the first demonstration of mammalian genotoxicity following exposure to CT-containing pavement sealcoat. This work provides in vivo evidence to support the contention that there may be adverse health effects in mammals, and potentially in humans, from exposure to coal tar. Environ. Mol. Mutagen. 57:535-545, 2016. © 2016 Her Majesty the Queen in Right of Canada. PMID:27473530

  10. Mortality among workers exposed to coal tar pitch volatiles and welding emissions: an exercise in epidemiologic triage.

    PubMed

    Silverstein, M; Maizlish, N; Park, R; Mirer, F

    1985-11-01

    The United Automobile Workers International Union has established a system of epidemiologic triage to evaluate patterns of mortality among groups of union members. In response to worker concerns, the Union examined mortality at a metal stamping plant, using a method which linked pension records with the State of Michigan computerized death registry. The observed proportion of malignant neoplasms was nearly twice that expected (95% Confidence Limits 1.36, 2.62). Two- to five-fold excess proportional mortality from cancer of the digestive organs, lung cancer, and leukemia accounted for most of the overall excess. Strong associations were found between lung and digestive organ cancer and employment as maintenance welders or millwrights in the plant (odds ratios greater than 10). High levels of six polycyclic aromatic hydrocarbons with mutagenic and carcinogenic properties were found during hot coal tar application to wood block floors, work conducted by the high-risk groups. These levels were substantially reduced following the purchase of new tar pots. The example demonstrates that epidemiologic tools can play a valuable role in occupational health decision making, but care must be taken to avoid mechanical reliance on quantitative testing and to acknowledge the important role of social and political value judgments in the establishment of responsible public policy. PMID:4051064

  11. Preliminary evaluation of ground-water contamination by coal-tar derivatives, St. Louis Park area, Minnesota

    USGS Publications Warehouse

    Hult, Marc F.; Schoenberg, Michael E.

    1984-01-01

    Drift materials on and south of the site have been contaminated by surface spills and by infiltration of contaminated process water. Near the contamination source, a hydrocarbon fluid phase is moving vertically downward relative to movement of the aqueous phase. Fluid pumped from an observation well in this area contained 6,000 milligrams per liter total organic carbon. Dissolved coal-tar constituents in the drift and the uppermost bedrock unit over most of the area, the Platteville aquifer, have moved at least 4,000 feet downgradient to a drift-filled bedrock valley. At the valley, it seems that the Platteville aquifer and the Glenwood confining bed have been removed by erosion and that contaminants with a concentration of approximately 2 milligrams per liter dissolved organic carbon are entering the underlying St. Peter aquifer. Chemical analyses of fluid pumped from observation wells suggest that soluble, low-molecular-weight compounds are moving preferentially through the drift and the Platteville aquifer.

  12. Method and apparatus for effectively eliminating tar-forming fractions and light oils from gases produced by coal gasification. [US patent

    SciTech Connect

    Bissett, L.A.

    1981-01-09

    The present invention is directed to a coal-gasification system in which tar-forming fractions and light oil-forming fractions in the combustible gases formed in the gasification chamber are eliminated in such a manner so that the sensible heat realized in the gasification operation can be retained for recovery. In the present system preheated air is introduced together with the tar-laden-producer gas into an afterburner chamber where partial combustion of the producer gas occurs and increases the temperature of the gases in the afterburner to a temperature sufficient to thermally decompose the tar-forming fractions to provide a tar-free product gas and soot which is easily separated from the gas stream. While the heating value of the producer gas is slightly reduced by this afterburning operation, the volume of producer gas is increased by the addition thereto of gases provided by the reduction of the light oil- and tar-forming fractions. Further, the sensible heat in the gas from the gasification operation and that provided by this additional combustion operation is easily recovered so as to provide a tar-removing system considerably more efficient than previously available.

  13. Using a battery of bioassays, benthic phytoplankton and the AUSRIVAS method to monitor long-term coal tar contaminated sediment in the Cache la Poudre River, Colorado.

    PubMed

    Oberholster, P J; Botha, A-M; Cloete, T E

    2005-12-01

    This survey provides information on sediment toxicity and structural characteristics of the macroinvertebrates and benthic phytoplankton at 10 locations in the Cache la Poudre River after long-term exposure to coal tar residue. The application of the Australian river bioassessment system (AUSRIVAS) as well as a biotest battery was used to evaluate the river 'health' condition. Coal tar is a dense nonaqueous-phase liquid of significant environmental concern due to its toxicity and persistence in the subsurface. Organisms like Selenastrum capricornutum, Daphnia magna and Chironomus tentans, representing different complexities in the biosphere, were selected as test systems for ecotoxicological studies. The results obtained in this study indicate that a biotest battery, macroinvertebrate and benthic phytoplankton communities are in principle suitable biological tools for evaluation of toxic oil and coal-derived substances in long-term contaminated river sediment. PMID:16289670

  14. Characterisation of dense non-aqueous phase liquids of coal tar using comprehensive two-dimensional gas chromatography coupled with time of flight mass spectrometry.

    NASA Astrophysics Data System (ADS)

    Gauchotte-Lindsay, Caroline; McGregor, Laura; Richards, Phil; Kerr, Stephanie; Glenn, Aliyssa; Thomas, Russell; Kalin, Robert

    2013-04-01

    Comprehensive two-dimensional gas chromatography (GCxGC) is a recently developed analytical technique in which two capillary columns with different stationary phases are placed in series enabling planar resolution of the analytes. The resolution power of GCxGC is one order of magnitude higher than that of one dimension gas chromatography. Because of its high resolution capacity, the use of GCxGC for complex environmental samples such as crude oils, petroleum derivatives and polychlorinated biphenyls mixtures has rapidly grown in recent years. We developed a one-step method for the forensic analysis of coal tar dense non-aqueous phase liquids (DNAPLs) from former manufactured gas plant (FMGP) sites. Coal tar is the by-product of the gasification of coal for heating and lighting and it is composed of thousands of organic and inorganic compounds. Before the boom of natural gases and oils, most towns and cities had one or several manufactured gas plants that have, in many cases, left a devastating environmental print due to coal tar contamination. The fate of coal tar DNAPLs, which can persist in the environment for more than a hundred years, is therefore of crucial interest. The presented analytical method consists of a unique clean-up/ extraction stage by pressurized liquid extraction and a single analysis of its organic chemical composition using GCxGC coupled with time of flight mass spectrometry (TOFMS). The chemical fingerprinting is further improved by derivatisation by N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) of the tar compounds containing -OH functions such as alcohols and carboxylic acids. We present here how, using the logical order of elution in GCxGC-TOFMS system, 1) the identification of never before observed -OH containing compounds is possible and 2) the isomeric selectivity of an oxidation reaction on a DNAPL sample can be revealed. Using samples collected at various FMGP sites, we demonstrate how this GCxGC method enables the simultaneous

  15. Contribution of PAHs from coal-tar pavement sealcoat and other sources to 40 U.S. lakes

    USGS Publications Warehouse

    Van Metre, Peter C.; Mahler, Barbara J.

    2010-01-01

    Contamination of urban lakes and streams by polycyclic aromatic hydrocarbons (PAHs) has increased in the United States during the past 40 years. We evaluated sources of PAHs in post-1990 sediments in cores from 40 lakes in urban areas across the United States using a contaminant mass-balance receptor model and including as a potential source coal-tar-based (CT) sealcoat, a recently recognized source of urban PAH. Other PAH sources considered included several coal- and vehicle-related sources, wood combustion, and fuel-oil combustion. The four best modeling scenarios all indicate CT sealcoat is the largest PAH source when averaged across all 40 lakes, contributing about one-half of PAH in sediment, followed by vehicle-related sources and coal combustion. PAH concentrations in the lakes were highly correlated with PAH loading from CT sealcoat (Spearman's rho=0.98), and the mean proportional PAH profile for the 40 lakes was highly correlated with the PAH profile for dust from CT-sealed pavement (r=0.95). PAH concentrations and mass and fractional loading from CT sealcoat were significantly greater in the central and eastern United States than in the western United States, reflecting regional differences in use of different sealcoat product types. The model was used to calculate temporal trends in PAH source contributions during the last 40 to 100 years to eight of the 40 lakes. In seven of the lakes, CT sealcoat has been the largest source of PAHs since the 1960s, and in six of those lakes PAH trends are upward. Traffic is the largest source to the eighth lake, located in southern California where use of CT sealcoat is rare.

  16. Task 1.15 - Enhanced Bioremediation of Coal Tar-Contaminated Soil

    SciTech Connect

    John R. Gallagher

    1998-02-01

    The remediation of sites where soils have been contaminated with hydrophobic organic compounds is a major problem. This is especially true for manufactured gas plants (MGP) and similar industries. Gasification of fossil fuels has resulted in the production of tars that contain polyaromatic hydrocarbons (PAHs). PAHs are of concern because they are persistent in the environment and because many of them are carcinogenic. When soils contain very high concentrations of PAHs and other tar components, it is generally most feasible to use a chemical-physical remediation technique such as incineration. However, when the contaminant concentrations are medium to low, the most inexpensive technology is generally biological treatment. Biological treatment is an environmentally acceptable method of remediation that is relatively low-cost for many organic contaminants. PAHs and similar hydrophobic compounds, however, present major challenges to the microbial methods. These problems can be broken down into two related areas: mass transfer and bioavailability. The water volubility of most PAW is very small, and they have very low vapor pressures. As a result the diffkion of the sorbed PAHs to a location where a biodegrading microorganism can encounter it is often limiting. Complicating this is that especially in aged samples, the PAHs are bound so strongly to soil components, they are not available for the microorganisms. These two phenomena can be better understood by examination of a typical biodegradation curve, such as might be observed for mixed PAHs. In Figure 1, there are three phases of the biodegradation process plotted with respect to time. In the first phase, concentrations are changing only slowly as the microbes adapt to the conditions, grow to a larger population, and begin to biodegrade the PAHs. The second phase is the phase of rapid, often logarithmic, biodegradation. The third and last phase is that period when available concentrations of PAHs are dropping so that

  17. Correlation of mutagenic potencies of various petroleum oils and oil coal tar mixtures with DNA adduct levels in vitro.

    PubMed

    Reddy, M V; Blackburn, G R; Schreiner, C A; Mackerer, C R

    1997-08-01

    An in vitro system was utilized to measure DNA adduct-forming ability of petroleum oils and oil coal tar mixtures to define correlations between DNA adduct levels and their mutagenic potencies. The system consisted of reaction of dimethyl sulfoxide extracts of oils with calf thymus DNA in the presence of Aroclor-induced hamster liver microsomes for 30 min. Following DNA extraction, DNA adducts were measured by the nuclease P1-enhanced postlabeling assay coupled with two-dimensional polyethyleneimine (PEI)-cellulose TLC. Thin layer plates showed putative aromatic DNA adducts, with levels ranging from 60 to 1400 adducts per 10(9) DNA nucleotides. TLC mobilities suggested adducts to be aromatic compounds containing 4 or more rings. A good correlation (coefficient of correlation = 0.91) was observed between DNA adduct levels and Salmonella mutagenicity for 19 oils. All 19 samples tested produced DNA adducts. To expedite the TLC procedure, adducts were resolved by one-dimensional TLC and the radioactivity measured using a mechanical scanner. Results were comparable to those obtained by two-dimensional TLC and quantification after scraping. Our data show that the in vitro incubation system coupled with the postlabeling adduct assay is a useful screening method to identify mutagenic and potentially carcinogenic oils. PMID:9288888

  18. A pilot study for the selection of a bioreactor for remediation of groundwater from a coal tar contaminated site.

    PubMed

    Guerin, Turlough F

    2002-01-28

    Coal tars in soil at a gasworks site in South Eastern Australia led to groundwater contamination with polycyclic aromatic hydrocarbons (PAHs), mono-aromatic compounds (BTEX) and phenols. The scope of the study included testwork in laboratory scale bioreactors and evaluation of available commercial groundwater treatment units. Two bioreactor configurations, a submerged fixed film reactor (SFFR) and a fluidized bed bioreactor (FBR) were effective, with high efficiencies of contaminant removal (typically >90%) over a range of hydraulic retention times (HRT) (3-29 h). Specifically, concentrations of total PAH, naphthalene, pyrene and total phenols in the feedstock and effluent of the SFFR were 123, 60, 51, 1.38 and 0.004, 0.001, 0.004, 0.1mg/l, respectively. The FBR was only marginally less effective than the SFFR for the same groundwater contaminants. Discharge to sewer was the most appropriate end use for the effluent. SFFRs are regarded as being simpler in design and operation, and a commercially available unit has been identified which would be suitable for treating small volumes (<10 m(3) per day) of contaminated water collected at an interception trench at the site. PMID:11744208

  19. Oil shale, tar sand, coal research, advanced exploratory process technology jointly sponsored research. Quarterly technical progress report, April--June 1992

    SciTech Connect

    Not Available

    1992-12-01

    Accomplishments for the quarter are presented for the following areas of research: oil shale, tar sand, coal, advanced exploratory process technology, and jointly sponsored research. Oil shale research includes; oil shale process studies, environmental base studies for oil shale, and miscellaneous basic concept studies. Tar sand research covers process development. Coal research includes; underground coal gasification, coal combustion, integrated coal processing concepts, and solid waste management. Advanced exploratory process technology includes; advanced process concepts, advanced mitigation concepts, and oil and gas technology. Jointly sponsored research includes: organic and inorganic hazardous waste stabilization; development and validation of a standard test method for sequential batch extraction fluid; operation and evaluation of the CO{sub 2} HUFF-N-PUFF Process; fly ash binder for unsurfaced road aggregates; solid state NMR analysis of Mesa Verde Group, Greater Green River Basin, tight gas sands; flow-loop testing of double-wall pipe for thermal applications; characterization of petroleum residue; shallow oil production using horizontal wells with enhanced recovery techniques; and menu driven access to the WDEQ Hydrologic Data Management Systems.

  20. Topical tar: Back to the future

    SciTech Connect

    Paghdal, K.V.; Schwartz, R.A.

    2009-08-15

    The use of medicinal tar for dermatologic disorders dates back to the ancient times. Although coal tar is utilized more frequently in modern dermatology, wood tars have also been widely employed. Tar is used mainly in the treatment of chronic stable plaque psoriasis, scalp psoriasis, atopic dermatitis, and seborrheic dermatitis, either alone or in combination therapy with other medications, phototherapy, or both. Many modifications have been made to tar preparations to increase their acceptability, as some dislike its odor, messy application, and staining of clothing. One should consider a tried and true treatment with tar that has led to clearing of lesions and prolonged remission times. Occupational studies have demonstrated the carcinogenicity of tar; however, epidemiologic studies do not confirm similar outcomes when used topically. This article will review the pharmacology, formulations, efficacy, and adverse effects of crude coal tar and other tars in the treatment of selected dermatologic conditions.

  1. Oil shale, tar sand, coal research advanced exploratory process technology, jointly sponsored research. Quarterly technical progress report, October--December 1992

    SciTech Connect

    Speight, J.G.

    1992-12-31

    Accomplishments for the past quarter are presented for the following five tasks: oil shale; tar sand; coal; advanced exploratory process technology; and jointly sponsored research. Oil shale research covers oil shale process studies. Tar sand research is on process development of Recycle Oil Pyrolysis and Extraction (ROPE) Process. Coal research covers: coal combustion; integrated coal processing concepts; and solid waste management. Advanced exploratory process technology includes: advanced process concepts;advanced mitigation concepts; and oil and gas technology. Jointly sponsored research includes: organic and inorganic hazardous waste stabilization; CROW field demonstration with Bell Lumber and Pole; development and validation of a standard test method for sequential batch extraction fluid; PGI demonstration project; operation and evaluation of the CO{sub 2} HUFF-N-PUFF Process; fly ash binder for unsurfaced road aggregates; solid state NMR analysis of Mesaverde Group, Greater Green River Basin, tight gas sands; flow-loop testing of double-wall pipe for thermal applications; characterization of petroleum residue; shallow oil production using horizontal wells with enhanced oil recovery techniques; surface process study for oil recovery using a thermal extraction process; NMR analysis of samples from the ocean drilling program; in situ treatment of manufactured gas plant contaminated soils demonstration program; and solid state NMR analysis of naturally and artificially matured kerogens.

  2. Oil shale, tar sand, coal research, advanced exploratory process technology, jointly sponsored research. Quarterly technical progress report, January--March 1993

    SciTech Connect

    Not Available

    1993-09-01

    Accomplishments for the past quarter are briefly described for the following areas of research: oil shale; tar sand; coal; advanced exploratory process technology; and jointly sponsored research. Oil shale and tar sand researches cover processing studies. Coal research includes: coal combustion; integrated coal processing concepts; and solid waste management. Advanced exploratory process technology covers: advanced process concepts; advanced mitigation concepts; and oil and gas technology. Jointly sponsored research includes: organic and inorganic hazardous waste stabilization; CROW{sup TM} field demonstration with Bell Lumber and Pole; development and validation of a standard test method for sequential batch extraction fluid; operation and evaluation of the CO{sub 2} HUFF-N-PUFF Process; fly ash binder for unsurfaced road aggregates; solid-state NMR analysis of Mesaverde Group, Greater Green River Basin tight gas sands; characterization of petroleum residue; shallow oil production using horizontal wells with enhanced oil recovery techniques; surface process study for oil recovery using a thermal extraction process; oil field waste cleanup using tank bottom recovery process; remote chemical sensor development; in situ treatment of manufactured gas plant contaminated soils demonstration program; solid-state NMR analysis of naturally and artificially matured kerogens; and development of an effective method for the clean-up of natural gas.

  3. Speciation of nitrogen-containing compounds in an unfractionated coal tar sample by comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry.

    PubMed

    da Silva, Juliana M; Machado, Maria Elisabete; Maciel, Gabriela P S; Dal Molin, Daniela; Caramão, Elina B

    2014-12-19

    Comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC/TOFMS) has shown great skill in analyzing complex mixtures such as fossil fuels, especially for compounds at low concentrations. The analysis of N-polyaromatic compounds (NPAC) in coal and crude oil is a great challenge for analytical chemistry due to its environmental and technological importance, and also its diversity of concentration in the matrix. This study is the first report in the applicability of GC×GC/TOFMS for detection of NPAC in a coal tar sample with no fractionation. Normally these compounds are analyzed after sample treatment, making the process expensive and time consuming. However, the higher separation power of GC×GC/TOFMS, compared to 1D-GC, produces cleaner mass spectra in complex samples, which helps in identification of analytes with no pre-fractionation. In this paper, the main objectives were to demonstrate the applicability of GC×GC/TOFMS in the speciation and separation between basic and neutral NPAC from coal tar sample derived from fast pyrolysis, without prior sample fractionation. The methodology used here consisted of chromatographic injection of the diluted sample using a conventional columns set and data analysis by ChromaTOF/Excel™ software. Some basic compounds (pyridines and quinolines) and neutral ones (carbazoles and indoles) were detected with good chromatographic separation and spectral similarity. Tools like spectral deconvolution, extracted ion chromatogram (EIC) and dispersion graphics allowed greater security on the identification and separation of NPAC in this complex sample of coal tar, with no pre-treatment. PMID:25464993

  4. Determination of the Forms of Nitrogen Released in Coal Tar During Rapid Devolatilization. Semi-annual report, May 1-October 31, 1997

    SciTech Connect

    Fletcher, T.H., Goldberg, P.

    1997-10-31

    The primary objective of this work is to determine the forms of nitrogen in coal that lead to nitrogen release during devolatilization. Experiments are to be performed in two existing laminar flow reactors available at Brigham Young University, which are both capable of temperatures (up to 2000 K), particle heating rates (104 to 105 K/s), and residence times (up to 500 ms) relevant to conditions commonly encountered in industrial pulverized coal combustors. The forms of nitrogen in coal, char, and tar samples are analyzed using state-of-the-art techniques, including nuclear magnetic resonance (NMR), X-Ray photoelectron spectroscopy (XPS), and high resolution nitrogen-specific chromatography. These sophisticated analysis techniques are being performed in collaboration with other researchers at BYU, the University of Utah, and industrial organizations. Coals have been obtained as a function of rank, including eight coals from the University of Utah that are to be used in pilot scale tests in support of the DOE Coal-2000 HIPPS (High Performance Power Systems) and LEBS (Low- Emission Boiler Systems) programs. Anticipated results from the proposed research are (a) nitrogen release parameters during devolatilization for specific coals pertinent to the HIPPS and LEBS projects, (b) better fundamental understanding of the chemistry of nitrogen release, and (c) a nitrogen release submodel based on fundamental chemistry that may be more widely applicable than existing empirical relationships.

  5. Dandruff, seborrheic dermatitis, and psoriasis drug products containing coal tar and menthol for over-the-counter human use; amendment to the monograph. Final rule

    SciTech Connect

    2006-03-15

    The Food and Drug Administration (FDA) is issuing a final rule amending the final monograph (FM) for over-the-counter (OTC) dandruff, seborrheic dermatitis, and psoriasis drug products to include the combination of 1.8 percent coal tar solution and 1.5 percent menthol in a shampoo drug product to control dandruff. FDA did not receive any comments or data in response to its previously proposed rule to include this combination. This final rule is part of FDA's ongoing review of OTC drug products.

  6. Natural horizontal transfer of a naphthalene dioxygenase gene between bacteria native to a coal tar-contaminated field site.

    PubMed Central

    Herrick, J B; Stuart-Keil, K G; Ghiorse, W C; Madsen, E L

    1997-01-01

    Horizontal transfer of genes responsible for pollutant biodegradation may play a key role in the evolution of bacterial populations and the adaptation of microbial communities to environmental contaminants. However, field evidence for horizontal gene transfer between microorganisms has traditionally been very difficult to obtain. In this study, the sequences of the 16S rRNA and naphthalene dioxygenase iron-sulfur protein (nahAc) genes of nine naphthalene-degrading bacteria isolated from a coal tar waste-contaminated site, as well as a naphthalene-degrading bacterium from a contaminated site in Washington state and two archetypal naphthalene-degrading strains, were compared. Seven strains from the study site had a single nahAc allele, whereas the 16S rRNA gene sequences of the strains differed by as much as 7.9%. No nahAc alleles from the site were identical to those of the archetypal strains, although the predominant allele was closely related to that of Pseudomonas putida NCIB 9816-4, isolated in the British Isles. However, one site-derived nahAc allele was identical to that of the Washington state strain. Lack of phylogenetic congruence of the nahAc and 16S rRNA genes indicates that relatively recent in situ horizontal transfer of the nahAc gene has occurred, possibly as a direct or indirect consequence of pollutant contamination. Alkaline lysis plasmid preparations and pulsed-field gel electrophoresis have revealed the presence of plasmids ranging in size from 70 to 88 kb in all site isolates. Southern hybridizations with a 407-bp nahAc probe have suggested that the nahAc gene is plasmid borne in all the site isolates but one, a strain isolated from subsurface sediment 400 m upstream from the source of the other site isolates. In this strain and in the naphthalene-degrading strain from Washington state, nahAc appears to be chromosomally located. In addition, one site isolate may carry nahAc on both chromosome and plasmid. Within the group of bacteria with

  7. Single event-driven export of polycyclic aromatic hydrocarbons and suspended matter from coal tar-contaminated soil

    SciTech Connect

    Totsche, K.U.; Jann, S.; Kogel-Knabner, I.

    2007-05-15

    Mobile colloidal and suspended matter is likely to affect the mobility of polycyclic aromatic hydrocarbons (PAHs) in the unsaturated soil zone at contaminated sites. We studied the release of mobile particles and dissolved organic matter as a function of variable climatic boundary conditions, and their effect on the export of PAHs at a coal tar-contaminated site using zero-tension lysimeters. Seepage water samples were analyzed for dissolved organic carbon (DOC), pH, electrical conductivity, turbidity, and particles larger than 0.7 {mu}m. The 16 Environmental Protection Agency PAHs were analyzed in the filtrate < 0.7 m and in the particle fraction. Our results show that extended no-flow periods that are followed by high-intensity rain events, such as thunderstorms, promote the mobilization of particles in the size 0.7 to 200 m. Mobilization is enforced by extended drying during summer. High particle concentrations are also associated with freezing and thawing cycles followed by either rain or snowmelt events. The export of PAHs is strongly connected to the release of particles in the 0.7- to 200-{mu}m size fraction. During the 2-yr monitoring period, up to 0.418 {mu}g kg{sup -1} PAHs were mobilized in the. ltrate (< 0.7 m) while the eightfold mass, 3.36 {mu}g kg{sup -1}, was exported with the retentate (0.7-200 {mu}m). Equilibrium dissolution of PAHs and transport in the dissolved phase seem to be of minor importance for the materials studied. Extreme singular-release events occurred in January 2003 and January 2004, when up to 55 {mu}g L{sup -1} PAHs per one single seepage event were observed within the retentate. Freezing and thawing cycles affect the PAH source materials, that is, the remnants of the nonaqueous phase liquid (NAPL). High mechanical strain during freezing results in the formation of particles. At the onset of the thawing and following rain or snowmelt events, PAHs associated with these particles are then exported from the lysimeter.

  8. An assessment of high and low temperature tars in Psoriasis.

    PubMed

    Chapman, R S; Finn, O A

    1976-01-01

    Comparison of the efficacy of crude coal tar from high and low temperature sources in the treatment of patients suffering from chronic psoriasis showed the tars to be equally effective. High temperature tar was then compared with standard refined tar. Again, an equal therapeutic response was achieved. Crude coal tars obtained by the carbonization of coal in coke ovens and in smokeless fuel manufacture can be employed in dermatological therapy in place of the dwindling supplies of crude tar of gasworks origin. PMID:1252342

  9. Food Allergy

    MedlinePlus

    ... navigation Home ▸ Conditions & Treatments ▸ Allergies ▸ Food Allergy Share | Food Allergy Overview Symptoms & Diagnosis Treatment & Management Food Allergy Overview If you have a food allergy, ...

  10. Ground-water flow in the Prairie du Chien-Jordan aquifer related to contamination by coal-tar derivatives, St Louis Park, Minnesota

    USGS Publications Warehouse

    Stark, J.R.; Hult, M.F.

    1985-01-01

    A Three-dimensional, finite-difference, groundwater flow model of the Prairie du Chien-Jordan aquifer was developed to assess the movement of coal-tar derivatives from a coal-tar distillation and wood-preserving plant in St. Louis Park, Minnesota. The model was calibrated for steady-state and transient conditions. Sensitivity testing indicated that leakage to the upper model layer and the vertical hydraulic conductivity of the basal confining unit of the St. Peter were the most sensitive model hydrologic properties. Model simulations indicated that water introduced into the aquifer through wells open to several aquifers would raise the potentiometric surface of the Prairie du Chien-Jordan by as much as 3 ft in the area of the former plant. Other simulations suggested that withdrawal from certain upgradient wells may have altered local hydraulic gradients. These factors contributed to the potential for movement of contaminants from the area of the former plant to wells. Simulations of a proposed gradient-control plan indicate that the actions would be effective in limiting the expansion of the contaminated volume. These simulations also show, however, that control of discharge from all wells in the area will be important to the overall effectiveness of the plan. (USGS)

  11. Implication of cytochrome P-450 1A isoforms and the AH receptor in the genotoxicity of coal-tar fume condensate and bitumen fume condensates.

    PubMed

    Genevois, C; Pfohl-Leszkowicz, A; Boillot, K; Brandt, H; Castegnaro, M

    1998-06-01

    During the hot application of bitumen- or coal-tar-containing materials, fumes are emitted that contain polycyclic aromatic compounds. Although workers' exposure to these fumes is low, it might lead to health problems. No study has reported the metabolic pathways involved in the genotoxicity of coal tar or bitumen fume condensates (CTFC, BFCs). We have therefore studied the DNA adducts formed by incubation of CTFC or BFCs with liver microsomes from several type of mice and with yeast microsomes expressing individual human CYP enzymes. Our results demonstrates that: (1) the aryl hydrocarbon receptor (AHR) plays an important role in the biotransformation of BFCs and to a lesser extent of CTFC; (2) for CTFC, both cytochrome P450 (CYP) 1A isoforms are involved in the formation of genotoxic compounds, and the reactive metabolites formed via CYP 1A1, are substrates for epoxide hydrolase (mEH); (3) for BFCs, the genotoxicity is partially dependent upon CYP 1A1 and the reactive metabolites are not substrates for mEH; (4) CYP 1A isoforms are not exclusively responsible for the genotoxicity of the CTFC and BFCs as other CYPs and also enzymes of the [AH] gene battery, may play an important role. PMID:21781875

  12. Oil shale, tar sand, coal research, advanced exploratory process technology, jointly sponsored research. Quarterly technical progress report, July--September 1992

    SciTech Connect

    Not Available

    1992-12-31

    Progress made in five research programs is described. The subtasks in oil shale study include oil shale process studies and unconventional applications and markets for western oil shale.The tar sand study is on recycle oil pyrolysis and extraction (ROPE) process. Four tasks are described in coal research: underground coal gasification; coal combustion; integrated coal processing concepts; and sold waste management. Advanced exploratory process technology includes: advanced process concepts; advanced mitigation concepts; and oil and gas technology. Jointly sponsored research covers: organic and inorganic hazardous waste stabilization; CROW field demonstration with Bell Lumber and Pole; development and validation of a standard test method for sequential batch extraction fluid; PGI demonstration project; operation and evaluation of the CO{sub 2} HUFF-N-PUFF process; fly ash binder for unsurfaced road aggregates; solid state NMR analysis of Mesaverde group, Greater Green River Basin, tight gas sands; flow-loop testing of double-wall pipe for thermal applications; shallow oil production using horizontal wells with enhanced oil recovery techniques; NMR analysis of sample from the ocean drilling program; and menu driven access to the WDEQ hydrologic data management system.

  13. Determination of the forms of nitrogen released in coal tar during rapid devolatilization. Semi-annual report, November 1, 1995--April 30, 1996

    SciTech Connect

    Fletcher, T.H.

    1996-04-30

    Control of emissions of nitrogen oxides (NO{sub x}) from coal combustion systems is becoming a major design and retrofit consideration. Most NO{sub x} in coal combustion systems comes from nitrogen in the fuel, rather than from nitrogen in the air. Practical emission control strategies include burner design strategies (e.g., low NO{sub x} burners), overfire air, reburning, selective non-catalytic reduction (SNCR) using reduction agents such as NH{sub 3} or urea, and selective catalytic reduction (SCR). The order listed also reflects the order of increasing costs for implementation. It is therefore most economically desirable to perform burner modifications to reduce NO{sub x} emissions rather than other control measures. Low-NO{sub x} burners work on the principle that devolatilized nitrogen species will form N{sub 2} rather than NO{sub x} under locally fuel-rich conditions with sufficient residence time at appropriate temperatures. The amount and form of nitrogen released during devolatilization influence the degree of NO{sub x} reduction attainable using burner design strategies for a given coal. Nitrogen in the char following devolatilization is released by heterogeneous oxidation, and may not be controlled by aerodynamic burner modifications. The objectives of this work are to perform detailed chemical measurements of the nitrogen in coal, tar, and char.

  14. Research investigations in oil shale, tar sand, coal research, advanced exploratory process technology, and advanced fuels research: Volume 1 -- Base program. Final report, October 1986--September 1993

    SciTech Connect

    Smith, V.E.

    1994-05-01

    Numerous studies have been conducted in five principal areas: oil shale, tar sand, underground coal gasification, advanced process technology, and advanced fuels research. In subsequent years, underground coal gasification was broadened to be coal research, under which several research activities were conducted that related to coal processing. The most significant change occurred in 1989 when the agreement was redefined as a Base Program and a Jointly Sponsored Research Program (JSRP). Investigations were conducted under the Base Program to determine the physical and chemical properties of materials suitable for conversion to liquid and gaseous fuels, to test and evaluate processes and innovative concepts for such conversions, to monitor and determine environmental impacts related to development of commercial-sized operations, and to evaluate methods for mitigation of potential environmental impacts. This report is divided into two volumes: Volume 1 consists of 28 summaries that describe the principal research efforts conducted under the Base Program in five topic areas. Volume 2 describes tasks performed within the JSRP. Research conducted under this agreement has resulted in technology transfer of a variety of energy-related research information. A listing of related publications and presentations is given at the end of each research topic summary. More specific and detailed information is provided in the topical reports referenced in the related publications listings.

  15. Optimization of {sup 1}H and {sup 13}C NMR methods for structural characterization of acetone and pyridine soluble/insoluble fractions of a coal tar pitch

    SciTech Connect

    Trevor J. Morgan; Anthe George; David B. Davis; Alan A. Herod; Rafael Kandiyoti

    2008-05-15

    {sup 1}H and {sup 13}C high-resolution liquid-state NMR methods were used for the quantitative characterization of different molecular weight fractions of a coal tar pitch (CTP). Three fractions were studied: pitch acetone solubles (PAS), pitch pyridine soluble-acetone insolubles (PPS), and pitch pyridine insolubles (PPI). Standard liquid-state NMR methods were modified and calibrated for use with undeuterated quinoline or undeuterated 1-methyl-2-pyrrolidinone (NMP) as the solvent. This made it possible to calculate the average structural parameters for the higher molecular weight (MW) fractions of the coal tar pitch. Quantitative comparisons of structural differences between the solubility-separated fractions of the pitch are reported. The aromaticity and the average number of aromatic rings per polynuclear aromatic structure were both found to decrease with increasing solubility. Similarly, pericondensed and all other quaternary carbon species were found to decrease with increasing solubility. This suggests that 'continental' type structures become more dominant as the solvent solubility of these coal derived fractions diminishes. The estimated average number of aromatic rings ranged from 1 to 2 rings in the PAS fraction, 4 to 21 rings in the PPS fraction, and 11 to 210 rings in the PPI fraction. These ring-numbers were directly related to the number average molecular mass (M{sub n}) assigned to the particular fraction in the average structural parameter (ASP) calculations. The lower-limit of the M{sub n} values was derived from the ASP calculations as 200, 450, and 6200 u for the PAS, PPS, and PPI fractions, respectively. 66 refs., 7 figs., 15 tabs.

  16. Process for hydrogenation of hydrocarbon tars

    DOEpatents

    Dolbear, Geoffrey E.

    1978-07-18

    Hydrocarbon tars of high asphaltene content such as tars obtained from pyrolysis of coal are dissolved in a solvent formed from the hydrogenation of the coal tars, and the resultant mixture hydrogenated in the presence of a catalyst at a pressure from about 1500 to 5000 psig at a temperature from about 500.degree. F to about the critical temperature of the solvent to form a light hydrocarbon as a solvent for the tars. Hydrogen content is at least three times the amount of hydrogen consumed.

  17. Allergy Capitals

    MedlinePlus

    ... Allergy Capitals Anaphylaxis in America Extreme Allergies and Climate Change Access to Pseudoephedrine Consensus Study on Food Allergies ... Allergy Capitals Anaphylaxis in America Extreme Allergies and Climate Change Access to Pseudoephedrine Consensus Study on Food Allergies ...

  18. Mold Allergy

    MedlinePlus

    ... the Allergist Health Professionals Partners Media Donate Allergies Mold Allergy What Is a Mold Allergy? If you have an allergy that occurs ... or basement. What Are the Symptoms of a Mold Allergy? The symptoms of mold allergy are very ...

  19. Oil shale, tar sand, coal research, advanced exploratory process technology, jointly sponsored research. Quarterly technical progress report, April--June 1993

    SciTech Connect

    Not Available

    1993-09-01

    Progress made in five areas of research is described briefly. The subtask in oil shale research is on oil shale process studies. For tar sand the subtask reported is on process development. Coal research includes the following subtasks: Coal combustion; integrated coal processing concepts; and solid waste management. Advanced exploratory process technology includes the following: Advanced process concepts; advanced mitigation concepts; oil and gas technology. Jointly sponsored research includes: Organic and inorganic hazardous waste stabilization; CROW{sup TM} field demonstration with Bell Lumber and Pole; development and validation of a standard test method for sequential batch extraction fluid; operation and evaluation of the CO{sup 2} HUFF-N-PUFF Process; fly ash binder for unsurfaced road aggregates; solid-state NMR analysis of Mesaverde Group, Greater Green River Basin, tight gas sands; characterization of petroleum residua; shallow oil production using horizontal wells with enhanced oil recovery techniques; surface process study for oil recovery using a thermal extraction process;NMR analysis of samples from the ocean drilling program; oil field waste cleanup using tank bottom recovery process; remote chemical sensor development; in situ treatment of manufactured gas plant contaminated soils demonstration program; solid-state NMR analysis of Mowry formation shale from different sedimentary basins; solid-state NMR analysis of naturally and artificially matured kerogens; and development of effective method for the clean-up of natural gas.

  20. An Open Label Prospective Randomized Trial to Compare the Efficacy of Coal Tar-Salicylic Acid Ointment Versus Calcipotriol/Betamethasone Dipropionate Ointment in the Treatment of Limited Chronic Plaque Psoriasis

    PubMed Central

    Khandpur, Sujay; Sahni, Kanika

    2014-01-01

    Background: Chronic plaque psoriasis is a common papulosquamous skin disorder, for which a number of topical agents are being used including coal tar, topical steroids and more recently topical calcipotriol/betamethasone dipropionate. There is no study comparing purified coal tar preparation with calcipotriol/betamethasone dipropionate ointment in limited chronic plaque psoriasis. Aims and Objectives: A prospective randomized open label controlled trial to compare the efficacy and safety of topical application of coal tar-salicylic acid ointment with calcipotriol/betamethasone dipropionate ointment applied once at night for 12 weeks for the treatment of limited chronic plaque psoriasis. Materials and Methods: A total of 62 patients of limited chronic plaque psoriasis (body surface area <10%) were randomized into two treatment groups: Group A received topical application of 6% coal tar with 3% salicylic acid ointment and Group B received calcipotriol/betamethasone dipropionate, once at night for 12 weeks. Results were assessed based on psoriasis area severity index (PASI) scores and patient global assessment (PGA) at each visit. Results: Mean PASI was significantly lower at week 2 (P = 0.01) and week 4 follow-up (P = 0.05) and the mean reduction in PASI was significantly higher at week 2 (P = 0.02) with calcipotriol/betamethasone than coal tar-salicylic acid, but this difference was not sustained at subsequent follow-up visits. Similarly, PGA scores at weeks 2 and 4 were significantly lower with calcipotriol/betamethasone dipropionate ointment (P = 0.003 and P = 0.007 respectively). There was no significant difference in any parameter during subsequent follow-up visits or at the end of the treatment phase (12 weeks). Conclusion: Topical nightly application of calcipotriol/betamethasone dipropionate ointment leads to an initial, more rapid reduction in disease severity, but the overall outcome parameters are comparable in the two treatment groups. PMID:25484388

  1. Mutagenic activity and polycyclic aromatic hydrocarbon levels in urine of workers exposed to coal tar pitch volatiles in an anode plant

    SciTech Connect

    Venier, P.; Clonfero, E.; Cottica, D.; Gava, C.; Zordan, M.; Pozzoli, L.; Levis, A.G.

    1985-05-01

    The mutagenicity of urinary extracts and the excretion of PAH from workers occupationally exposed to coal tar pitch volatiles in an anode plant were analyzed. Mutagenicity of the urinary extracts was measured by means of the plate test using S. typhimurium strain TA 98. After concentration, hydrolysis and reduction of the urine samples, PAH levels were measured by high resolution gas chromatography/mass spectrometry. No significant difference was found in the mutagenicity of the urinary extracts of non-smokers occupationally exposed to PAH as compared with the controls. Low PAH concentrations were found in the urine of the exposed subjects, which lends further support to the negative results obtained with the Ames test. The increase of urinary PAH excretion, in relation to occupational exposure, was mainly due to the less mutagenic, low molecular weight compounds.

  2. Exposure to runoff from coal-tar-sealed pavement induces genotoxicity and impairment of DNA repair capacity in the RTL-W1 fish liver cell line.

    PubMed

    Kienzler, Aude; Mahler, Barbara J; Van Metre, Peter C; Schweigert, Nathalie; Devaux, Alain; Bony, Sylvie

    2015-07-01

    Coal-tar-based (CTB) sealcoat, frequently applied to parking lots and driveways in North America, contains elevated concentrations of polycyclic aromatic hydrocarbons (PAHs) and related compounds. The RTL-W1 fish liver cell line was used to investigate two endpoints (genotoxicity and DNA-repair-capacity impairment) associated with exposure to runoff from asphalt pavement with CTB sealcoat or with an asphalt-based sealcoat hypothesized to contain about 7% CTB sealcoat (AS-blend). Genotoxic potential was assessed by the Formamido pyrimidine glycosylase (Fpg)-modified comet assay for 1:10 and 1:100 dilutions of runoff samples collected from 5 h to 36 d following sealcoat application. DNA-repair capacity was assessed by the base excision repair comet assay for 1:10 dilution of samples collected 26 h and 36 d following application. Both assays were run with and without co-exposure to ultraviolet-A radiation (UVA). With co-exposure to UVA, genotoxic effects were significant for both dilutions of CTB runoff for three of four sample times, and for some samples of AS-blend runoff. Base excision repair was significantly impaired for CTB runoff both with and without UVA exposure, and for AS-blend runoff only in the absence of UVA. This study is the first to investigate the effects of exposure to the complex mixture of chemicals in coal tar on DNA repair capacity. The results indicate that co-exposure to runoff from CT-sealcoated pavement and UVA as much as a month after sealcoat application has the potential to cause genotoxicity and impair DNA repair capacity. PMID:25795989

  3. Exposure to runoff from coal-tar-sealed pavement induces genotoxicity and impairment of DNA repair capacity in the RTL-W1 fish liver cell line

    USGS Publications Warehouse

    Kienzler, Aude; Mahler, Barbara J.; Van Metre, Peter C.; Schweigert, Nathalie; Devaux, Alain; Bony, Sylvie

    2015-01-01

    Coal-tar-based (CTB) sealcoat, frequently applied to parking lots and driveways in North America, contains elevated concentrations of polycyclic aromatic hydrocarbons (PAHs) and related compounds. The RTL-W1 fish liver cell line was used to investigate two endpoints (genotoxicity and DNA-repair-capacity impairment) associated with exposure to runoff from asphalt pavement with CTB sealcoat or with an asphalt-based sealcoat hypothesized to contain about 7% CTB sealcoat (AS-blend). Genotoxic potential was assessed by the Formamido pyrimidine glycosylase (Fpg)-modified comet assay for 1:10 and 1:100 dilutions of runoff samples collected from 5 h to 36 d following sealcoat application. DNA-repair capacity was assessed by the base excision repair comet assay for 1:10 dilution of samples collected 26 h and 36 d following application. Both assays were run with and without co-exposure to ultraviolet-A radiation (UVA). With co-exposure to UVA, genotoxic effects were significant for both dilutions of CTB runoff for three of four sample times, and for some samples of AS-blend runoff. Base excision repair was significantly impaired for CTB runoff both with and without UVA exposure, and for AS-blend runoff only in the absence of UVA. This study is the first to investigate the effects of exposure to the complex mixture of chemicals in coal tar on DNA repair capacity. The results indicate that co-exposure to runoff from CT-sealcoated pavement and UVA as much as a month after sealcoat application has the potential to cause genotoxicity and impair DNA repair capacity.

  4. Mold Allergy

    MedlinePlus

    ... navigation Home ▸ Conditions & Treatments ▸ Allergies ▸ Mold Allergy Share | Mold Allergy Overview Symptoms & Diagnosis Treatment & Management Mold Allergy Overview Molds are tiny fungi whose spores ...

  5. Estimating release of polycyclic aromatic hydrocarbons from coal-tar contaminated soil at manufactured gas plant sites. Final report

    SciTech Connect

    Lee, L.S.

    1998-04-01

    One of EPRI`s goals regarding the environmental behavior of organic substances consists of developing information and predictive tools to estimate the release potential of polycyclic aromatic hydrocarbons (PAHs) from contaminated soils at manufactured gas (MGP) plant sites. A proper assessment of the distribution of contaminants under equilibrium conditions and the potential for mass-transfer constraints is essential in evaluating the environmental risks of contaminants in the subsurface at MGP sites and for selecting remediation options. The results of this research provide insights into estimating maximum release concentrations of PAHs from MGP soils that have been contaminated by direct contact with the tar or through years of contact with contaminated groundwater. Attention is also given to evaluating the use of water-miscible cosolvents for estimating aqueous phase concentrations, and assessing the role of mass-transfer constraints in the release of PAHs from MGP site soils.

  6. Cockroach Allergy

    MedlinePlus

    ... regularly. Avoid leaving pet food out in a bowl. Clean the bowl regularly, like other dirty dishes. Fix leaky pipes ... Medical Review October 2015. Insect Allergies Cockroach Allergy Dust Mite Allergy Types of Allergies Drug Allergy Food ...

  7. Mortality and cancer experience of Quebec aluminum reduction plant workers. Part I: The reduction plants and coal tar pitch volatile (CTPV) exposure assessment

    SciTech Connect

    Lavoue, J.; Gerin, M.; Cote, J.; Lapointe, R.

    2007-09-15

    This paper presents the exposure assessment and job-exposure matrix (JEM) used to estimate coal tar pitch volatile (CTPV) exposure for a study of mortality and cancer incidence in aluminum smelter workers in Quebec, Canada. Historical CTPV exposure was assessed by estimating benzene-soluble material (BSM) and benzo(a)pyrene (B(a)P) levels for combinations of job and time period. Estimates were derived by using several procedures including averaging measurement data, a deterministic mathematical model using process-related correction factors, and expert-based extrapolation. The JEM comprised 28,910 jobs, covering 7 facilities from 1916 to 1999. Estimated exposures ranged from 0.01 {mu} g/m{sup 3} to 68.08 {mu} g/m{sup 3} (B(a)P) and 0.01 mg/m{sup 3} to 3.64 mg/m{sup 3} (BSW) and were lowest before 1940 and after 1980. This methodology constitutes an improvement compared with methods used for previous studies of the Quebec cohort.

  8. Assessment of intrinsic bioremediation of a coal-tar-affected aquifer using two-dimensional reactive transport and biogeochemical mass balance approaches

    SciTech Connect

    Rogers, S.W.; Ong, S.K.; Stenback, G.A.; Golchin, J.; Kjartanson, B.H.

    2007-01-15

    Expedited site characterization and groundwater monitoring using direct-push technology and conventional monitoring wells were conducted at a former manufactured gas plant site. Biogeochemical data and heterotrophic plate counts support the presence of microbially mediated remediation. By superimposing solutions of a two-dimensional reactive transport analytical model, first-order degradation rate coefficients (day{sup -1}) of various compounds for the dissolved-phase plume were estimated (i.e., benzene (0.0084), naphthalene (0.0058), and acenaphthene (0.0011)). The total mass transformed by aerobic respiration, nitrate reduction, and sulfate reduction around the free-phase coal-tar dense-nonaqueous-phase-liquid region and in the plume was estimated to be approximately 4.5 kg/y using a biogeochemical mass-balance approach. The total mass transformed using the degradation rate coefficients was estimated to be approximately 3.6 kg/y. Results showed that a simple two-dimensional analytical model and a biochemical mass balance with geochemical data from expedited site characterization can be useful for rapid estimation of mass-transformation rates.

  9. Laboratory differential simulation design method of pressure absorbers for carbonization of phenolate solution by carbon dioxide in coal-tar processing

    SciTech Connect

    Linek, V.; Sinkule, J.; Moucha, T.; Rejl, J.F.

    2009-01-15

    A laboratory differential simulation method is used for the design of carbonization columns at coal-tar processing in which phenols are regenerated from phenolate solution by carbon dioxide absorption. The design method is based on integration of local absorption rates of carbon dioxide along the column. The local absorption rates into industrial phenolate mixture are measured in a laboratory model contactor for various compositions of the gas and liquid phases under the conditions that ensure the absorption rates in the laboratory absorber simulate the local rates in the industrial column. On the bases of the calculations, two-step carbonization columns were designed for 30000 t/year of the phenolate solution treatment by carbon dioxide. The absorption proceeds at higher pressure of 500 kPa and temperatures from 50 to 65 C, pure carbon dioxide is used and toluene is added. These conditions have the following favourable effects: (I) significant size reduction of the columns, (ii) it is possible to process more concentrated solutions without danger of silting the columns by crystallization of NaHCO{sub 3} on the packing. (iii) small amount of inert gas is released, (iv) lower alkalinity and better separability of the organic phase (phenols with toluene) from water phase (soda or bicarbonate solution) in separators.

  10. Fish Allergy

    MedlinePlus

    ... Story" 5 Things to Know About Zika & Pregnancy Fish Allergy KidsHealth > For Parents > Fish Allergy Print A ... From Home en español Alergia al pescado About Fish Allergy A fish allergy is not exactly the ...

  11. Food Allergies

    MedlinePlus

    ... Got Homework? Here's Help White House Lunch Recipes Food Allergies KidsHealth > For Kids > Food Allergies Print A ... cow's milk eggs soy wheat What Is a Food Allergy? Food allergies happen when the immune system ...

  12. Milk Allergy

    MedlinePlus

    ... How Can I Help a Friend Who Cuts? Milk Allergy KidsHealth > For Teens > Milk Allergy Print A ... on to find out. What Happens With a Milk Allergy? Food allergies involve the body's immune system, ...

  13. Tar sands

    SciTech Connect

    Wennekers, J.H.N.

    1981-10-01

    The four largest oil sand deposits contain over 90% of the world's known heavy oil. The total heavy oil and bitumen in place, estimated at nearly 6 trillion barrels is almost entirely concentrated in western Canada, principally Alberta, and eastern Venezuela. The known tar sand resource in the United States consists of about 550 occurrences located in 22 states. The total oil in place in 39 of these occurrences is estimated to be between 23.7 billion and 32.7 billion barrels. At least 90% of this resource is located in Utah. Other significant deposits are in Texas, New Mexico, California, and Kentucky. Bituminous sand deposits and petroleum-impregnated rocks are found in Malagasy, Albania, Rumania, the USSR, and Trinidad. 4 figures, 2 tables. (DP)

  14. Characterization and organic electric-double-layer-capacitor application of KOH activated coal-tar-pitch-based carbons: Effect of carbonization temperature

    NASA Astrophysics Data System (ADS)

    Choi, Poo Reum; Lee, Eunji; Kwon, Soon Hyung; Jung, Ji Chul; Kim, Myung-Soo

    2015-12-01

    The present study reports the influence of pre-carbonization on the properties of KOH-activated coal tar pitch (CTP). The change of crystallinity and pore structure of pre-carbonized CTPs as well as their activated carbons (ACs) as function of pre-carbonization temperature are investigated. The crystallinity of pre-carbonized CTPs increases with increasing the carbonization temperature up to 600 °C, but a disorder occurs during the carbonization around 700 °C and an order happens gradually with increasing the carbonization temperatures in range of 800-1000 °C. The CTPs pre-carbonized at high temperatures are more difficult to be activated with KOH than those pre-carbonized at low temperatures due to the increase of micro-crystalline size and the decrease of surface functional groups. The micro-pores and meso-pores are well developed at around 1.0 nm and 2.4 nm, respectively, as the ACs are pre-carbonized at temperatures of 500-600 °C, exhibiting high specific capacitances as electrode materials for electric double layer capacitor (EDLC). Although the specific surface area (SSA) and pore volume of ACs pre-carbonized at temperatures of 900-1000 °C are extraordinary low (non-porous) as compared to those of AC pre-carbonized at 600 °C, their specific capacitances are comparable to each other. The large specific capacitances with low SSA ACs can be attributed to the structural change resulting from the electrochemical activation during the 1st charge above 2.0 V.

  15. Competitive inhibition of carcinogen-activating CYP1A1 and CYP1B1 enzymes by a standardized complex mixture of PAH extracted from coal tar

    SciTech Connect

    Mahadevan, B.; Marston, C.P.; Luch, A.; Dashwood, W.M.; Brooks, E.; Pereira, C.; Doehmer, J.; Baird, W.M.

    2007-03-15

    A complex mixture of polycyclic aromatic hydrocarbons (PAH) extracted from coal tar, the Standard Reference Material (SRM) 1597, was recently shown to decrease the levels of DNA binding of the 2 strong carcinogens benzo(a)pyrene (BP) and dibenzo(a,l)pyrene (DBP) in the human mammary carcinoma-derived cell line MCF-7. The present study was designed to further elucidate the biochemical mechanisms involved in this inhibition process. We examined the effects of SRM 1597 on the metabolic activation of BP and DBP toward DNA-binding derivatives in Chinese hamster cells expressing either human cytochrome P450 (CYP) 1A1 or CYP1B1. The data obtained from biochemical experiments revealed that SRM 1597 competitively inhibited the activity of both human enzymes as analyzed by 7-ethoxyresorufin O-deethylation assays. While the Michaelis-Menten constant (K-M) was {lt} 0.4 {mu}M in the absence of SRM 1597, this value increased up to 1.12 (CYP1A1) or 4.45 {mu}M (CYP1B1) in the presence of 0.1 {mu} g/ml SRM 1597. Hence the inhibitory effects of the complex mixture on human CYP1B1 were much stronger when compared to human CYP1A1 Taken together, the decreases in PAH-DNA adduct formation on co-treatment with SRM 1597 revealed inhibitory effects on the CYP enzymes that convert carcinogenic PAH into DNA-binding metabolites. The implications for the tumorigenicity of complex environmental PAR mixtures are discussed.

  16. Abundance of Dioxygenase Genes Similar to Ralstonia sp. Strain U2 nagAc Is Correlated with Naphthalene Concentrations in Coal Tar-Contaminated Freshwater Sediments

    PubMed Central

    Dionisi, Hebe M.; Chewning, Christopher S.; Morgan, Katherine H.; Menn, Fu-Min; Easter, James P.; Sayler, Gary S.

    2004-01-01

    We designed a real-time PCR assay able to recognize dioxygenase large-subunit gene sequences with more than 90% similarity to the Ralstonia sp. strain U2 nagAc gene (nagAc-like gene sequences) in order to study the importance of organisms carrying these genes in the biodegradation of naphthalene. Sequencing of PCR products indicated that this real-time PCR assay was specific and able to detect a variety of nagAc-like gene sequences. One to 100 ng of contaminated-sediment total DNA in 25-μl reaction mixtures produced an amplification efficiency of 0.97 without evident PCR inhibition. The assay was applied to surficial freshwater sediment samples obtained in or in close proximity to a coal tar-contaminated Superfund site. Naphthalene concentrations in the analyzed samples varied between 0.18 and 106 mg/kg of dry weight sediment. The assay for nagAc-like sequences indicated the presence of (4.1 ± 0.7) × 103 to (2.9 ± 0.3) × 105 copies of nagAc-like dioxygenase genes per μg of DNA extracted from sediment samples. These values corresponded to (1.2 ± 0.6) × 105 to (5.4 ± 0.4) × 107 copies of this target per g of dry weight sediment when losses of DNA during extraction were taken into account. There was a positive correlation between naphthalene concentrations and nagAc-like gene copies per microgram of DNA (r = 0.89) and per gram of dry weight sediment (r = 0.77). These results provide evidence of the ecological significance of organisms carrying nagAc-like genes in the biodegradation of naphthalene. PMID:15240274

  17. Macrophages Facilitate Coal Tar Pitch Extract-Induced Tumorigenic Transformation of Human Bronchial Epithelial Cells Mediated by NF-κB

    PubMed Central

    Feng, Feifei; Wu, Yiming; Zhang, Shaofeng; Liu, Yu; Qin, Lijuan; Wu, Yongjun; Yan, Zhen; Wu, Weidong

    2012-01-01

    Objective Chronic respiratory inflammation has been associated with lung cancer. Tumor-associated macrophages (TAMs) play a critical role in the formation of inflammation microenvironment. We sought to characterize the role of TAMs in coal tar pitch extract (CTPE)-induced tumorigenic transformation of human bronchial epithelial cells and the underlying mechanisms. Methods The expression of TAMs-specific CD68 in lung cancer tissues and paired adjacent tissues from cancer patients was determined using immunostaining. Co-culture of human bronchial epithelial cells (BEAS-2B) and macrophage-like THP-1 cells were conducted to evaluate the promotive effect of macrophages on CTPE-induced tumorigenic transformation of BEAS-2B cells. BEAS-2B cells were first treated with 2.4 µg/mL CTPE for 72 hours. After removal of CTPE, the cells were continuously cultured either with or without THP-1 cells and passaged using trypsin-EDTA. Alterations of cell cycle, karyotype, colony formation in soft agar and tumor xenograft growth in nude mice of BEAS-2B cells at passages 10, 20 and 30, indicative of tumorigenecity, were determined, respectively. In addition, mRNA and protein levels of NF-κB in BEAS-2B cells were measured with RT-PCR and western blot, respectively. B(a)P was used as the positive control. Results The over-expression of TAMs-specific CD68 around lung tumor tissues was detected and associated with lung cancer progression. The tumorigenic alterations of BEAS-2B cells including increase in cell growth rate, number of cells with aneuploidy, clonogenicity in soft agar, and tumor size in nude mice in vivo occurred at passage 10, becoming significant at passages 20 and 30 of the co-culture following CTPE removal in compared to BEAS-2B cells alone. In addition, the expression levels of NF-κB in BEAS-2B cells were positively correlated to the malignancy of BEAS-2B cells under different conditions of treatment. Conclusion The presence of macrophages facilitated CTPE

  18. Coal-Tar-Sealcoated Parking Lots: "Hot spots" of PAHs and N-heterocycles to Urban Streams and Lakes Result in "Hot Moments" of Toxicity

    NASA Astrophysics Data System (ADS)

    Mahler, B. J.; Van Metre, P. C.; Ingersoll, C.; Kunz, J. L.

    2014-12-01

    Coal-tar (CT) sealcoat, a potent source of polycyclic aromatic hydrocarbons (PAHs) and N-heterocycles, is applied to asphalt pavement of parking lots and driveways in many parts of the U.S. and Canada every 1 to 5 years. We measured the chemistry and toxicity of unfiltered runoff resulting from rain events simulated from 5 hours to 111 days after application of CT or asphalt (AS) sealcoat. PAHs and N-heterocycles were measured by GC/EIMS. Toxicity tests were done with Ceriodaphnia dubia and Pimephales promelas exposed 48 hours to undiluted and diluted (1 part runoff 9 parts control water) runoff under ambient lighting. Organisms were then transferred to fresh control water and subjected to a 4-hour pulse of ultraviolet radiation (UVR). Concentrations of 2- and 3-ringed PAHs and N-heterocycles in CT runoff, initially high (sum of 6 PAHs, 220 μg/L; sum of 7 N-heterocycles, 904 μg/L), decreased rapidly, whereas concentrations of 4-, 5- and 6-ringed PAHs more than doubled by 7 days after application (sum of 9 PAHs, 378 μg/L) and remained elevated 111 days after application (sum of 9 PAHs, 283 μg/L). Concentrations of PAHs and N-heterocycles in AS sealcoated runoff followed a similar pattern, but were ~10 times lower than those in CT runoff; concentrations in a sample of runoff from unsealed asphalt pavement were near or less than the detection limit. Organisms exposed to samples of undiluted CT-runoff collected during the 36 days following CT sealcoat application (no UVR exposure) experienced 100% mortality. Mortality (as much as 100%) of organisms exposed to the 10% dilution of CT runoff or to undiluted AS runoff occurred only with UVR; mortality of organisms exposed to the 10% solution of AS runoff and UVR was minimal. Results demonstrate that freshly CT-sealed parking lots and driveways are "hot spots" of PAH and N-heterocycle contamination and that prolonged "hot moments" of toxicity follow CT sealcoat application.

  19. Egg Allergy

    MedlinePlus

    ... Story" 5 Things to Know About Zika & Pregnancy Egg Allergy KidsHealth > For Parents > Egg Allergy Print A ... labels carefully. It's work, but it's important. About Egg Allergy Eggs in themselves aren't bad, but ...

  20. Egg Allergy

    MedlinePlus

    ... Got Homework? Here's Help White House Lunch Recipes Egg Allergy KidsHealth > For Kids > Egg Allergy Print A ... with no problem after that. What Is an Egg Allergy? You probably know that some people are ...

  1. Food Allergies

    MedlinePlus

    ... of food, most food allergies are caused by tree nuts, peanuts, milk, eggs, soy, wheat, fish and ... all do. People rarely outgrow allergies to peanuts, tree nuts, fish and shellfish Other Organizations Food Allergy ...

  2. Oxidative Damage to Nucleic Acids and Benzo(a)pyrene-7,8-diol-9,10-epoxide-DNA Adducts and Chromosomal Aberration in Children with Psoriasis Repeatedly Exposed to Crude Coal Tar Ointment and UV Radiation

    PubMed Central

    Andrys, Ctirad; Palicka, Vladimir; Chmelarova, Marcela; Hamakova, Kvetoslava

    2014-01-01

    The paper presents a prospective cohort study. Observed group was formed of children with plaque psoriasis (n=19) treated by Goeckerman therapy (GT). The study describes adverse (side) effects associated with application of GT (combined exposure of 3% crude coal tar ointment and UV radiation). After GT we found significantly increased markers of oxidative stress (8-hydroxy-2′-deoxyguanosine, 8-hydroxyguanosine, and 8-hydroxyguanine), significantly increased levels of benzo[a]pyrene-7,8-diol-9,10-epoxide (BPDE) DNA adducts (BPDE-DNA), and significantly increased levels of total number of chromosomal aberrations in peripheral lymphocytes. We found significant relationship between (1) time of UV exposure and total number of aberrated cells and (2) daily topical application of 3% crude coal tar ointment (% of body surface) and level of BPDE-DNA adducts. The findings indicated increased hazard of oxidative stress and genotoxic effects related to the treatment. However, it must be noted that the oxidized guanine species and BPDE-DNA adducts also reflect individual variations in metabolic enzyme activity (different extent of bioactivation of benzo[a]pyrene to BPDE) and overall efficiency of DNA/RNA repair system. The study confirmed good effectiveness of the GT (significantly decreased PASI score). PMID:25197429

  3. Allergy Testing

    MedlinePlus

    American Academy of Allergy Asthma & Immunology Menu Search Main navigation Skip to content Conditions & Treatments Allergies Asthma Primary Immunodeficiency Disease Related Conditions Drug Guide Conditions Dictionary Just ...

  4. Process for detoxifying coal tars

    DOEpatents

    Longwell, John P.; Peters, William A.

    1983-01-01

    A process for treating liquid hydrocarbons to remove toxic, mutagenic and/or carcinogenic aromatic hydrocarbons comprises feeding the hydrocarbons into a reactor where vapors are thermally treated in contact with a catalyst consisting essentially of calcium oxide or a calcium oxide containing mineral. Thermally treating liquid hydrocarbons in contact with calcium oxide preferentially increases the cracking of aromatics thus producing a product having a reduced amount of aromatic compounds.

  5. Research investigations in oil shale, tar sand, coal research, advanced exploratory process technology, and advanced fuels research: Volume 2 -- Jointly sponsored research program. Final report, October 1986--September 1993

    SciTech Connect

    Smith, V.E.

    1994-09-01

    Numerous studies have been conducted in five principal areas: oil shale, tar sand, underground coal gasification, advanced process technology, and advanced fuels research. In subsequent years, underground coal gasification was broadened to be coal research, under which several research activities were conducted that related to coal processing. The most significant change occurred in 1989 when the agreement was redefined as a Base Program and a Jointly Sponsored Research Program (JSRP). Investigations were conducted under the Base Program to determine the physical and chemical properties of materials suitable for conversion to liquid and gaseous fuels, to test and evaluate processes and innovative concepts for such conversions, to monitor and determine environmental impacts related to development of commercial-sized operations, and to evaluate methods for mitigation of potential environmental impacts. This report is divided into two volumes: Volume 1 consists of 28 summaries that describe the principal research efforts conducted under the Base Program in five topic areas. Volume 2 describes tasks performed within the JSRP. Research conducted under this agreement has resulted in technology transfer of a variety of energy-related research information. A listing of related publications and presentations is given at the end of each research topic summary. More specific and detailed information is provided in the topical reports referenced in the related publications listings.

  6. A coke oven model including thermal decomposition kinetics of tar

    SciTech Connect

    Munekane, Fuminori; Yamaguchi, Yukio; Tanioka, Seiichi

    1997-12-31

    A new one-dimensional coke oven model has been developed for simulating the amount and the characteristics of by-products such as tar and gas as well as coke. This model consists of both heat transfer and chemical kinetics including thermal decomposition of coal and tar. The chemical kinetics constants are obtained by estimation based on the results of experiments conducted to investigate the thermal decomposition of both coal and tar. The calculation results using the new model are in good agreement with experimental ones.

  7. Comparative anti-dandruff efficacy between a tar and a non-tar shampoo.

    PubMed

    Piérard-Franchimont, C; Piérard, G E; Vroome, V; Lin, G C; Appa, Y

    2000-01-01

    A randomized double-blind clinical study was conducted on two groups of 30 volunteers using either a non-tar shampoo (2% salicylic acid, 0.75% piroctone olamine and 0.5% elubiol) or a 0.5% coal tar shampoo. Subjects were diagnosed as having moderate to marked dandruff. The study consisted of a 3-week washout, followed by a 4-week treatment and a 4-week posttreatment regression phase. The clinical evaluations and subject self-assessments showed that the non-tar shampoo was as effective as the tar shampoo. Both received high approval ratings (> or =70%). Biometrological methods proved to be more sensitive than clinical evaluations to assess the efficacy of the shampoos. The non-tar shampoo yielded a significantly better reduction of Malassezia spp. counts (p<0.02) during the treatment phase and reduced the spontaneous increase in squamometry values (p< 0.01) during the posttreatment phase. It is concluded that a formulation associating salicylic acid, piroctone olamine and elubiol exhibited increased beneficial effects compared to the coal tar shampoo. PMID:10773717

  8. In vitro studies of the genotoxic effects of bitumen and coal-tar fume condensates: comparison of data obtained by mutagenicity testing and DNA adduct analysis by 32P-postlabelling.

    PubMed

    De Méo, M; Genevois, C; Brandt, H; Laget, M; Bartsch, H; Castegnaro, M

    1996-08-14

    Bitumens contain traces of polycyclic aromatic compounds (PACs), a part of which will end up in the fumes emitted during hot handling of bitumen-containing products, e.g. during roadpaving. Although exposure of workers to these fumes is low, it might lead to health problems. Studies on bitumen fume condensates (BFCs) showed weak to moderate mutagenic activities, but studies on DNA adduct formation have not been reported. Therefore, a study was initiated in which fumes were generated from two road grade bitumens, in such a way that they were representative of the fumes produced in the field. The combined vapour/particulates were tested in vitro for their ability to produce DNA adducts and in modified Ames mutation assays, using a number of different strains. An attempt was made to relate the results to chemical data, such as the content of a number of individual polycyclic aromatic hydrocarbons (PAHs) and with a measure for the total PAC content. As a reference material fume condensate from coal-tar (coal-tar pitch volatiles; CTPV) were subjected to the same tests. All fume condensates tested were mutagenic to all strains and induced the formation of DNA adducts. The patterns of DNA adducts, obtained by 32P-postlabelling, arising from the BFCs were qualitatively different from the patterns of adducts obtained from the CTPVs, implying qualitative differences in the nature of the compounds responsible for the formation of these adducts. This is corroborated by the observation that for BFCs quantitative adduct levels are higher than would be expected based on the PAH content. These data thus indicate that the PAHs analysed are not the sole components responsible for adduct formation from BFCs, but that an important contribution comes from other (hetero- and/or substituted-) PACs. PMID:8760390

  9. Food Allergy

    MedlinePlus

    Food allergy is an abnormal response to a food triggered by your body's immune system. In adults, the foods ... a severe reaction called anaphylaxis. Symptoms of food allergy include Itching or swelling in your mouth Vomiting, ...

  10. Allergies - overview

    MedlinePlus

    ... an infection. Skin testing is the most common method of allergy testing: The prick test involves placing ... Chiriac AM, Bousquet J, Demoly P. In vivo methods for the study and diagnosis of allergy. In: ...

  11. Environmental Allergies

    MedlinePlus

    ... system to a normally harmless substance called an allergen. A variety of environmental allergens, such as pollen and animal dander, can trigger ... allergies. Understanding Environmental Allergies Cause Symptoms Diagnosis Treatments Immunotherapy Last Updated April 22, 2015 CONNECT WITH NIAID ...

  12. Environmental stability of PAH source indices in pyrogenic tars

    SciTech Connect

    Uhler, A.D.; Emsbo-Mattingly, S.D.

    2006-04-15

    Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental contaminants found in soil, sediments, and airborne particulates. The majority of PAHs found in modern soils and sediments arise from myriad anthropogenic petrogenic and pyrogenic sources. Tars and tar products such as creosote produced from the industrial pyrolysis of coal or oil at former manufactured gas plants (MGPs) or in coking retorts are viscous, oily substances that contain significant concentrations of PAH, usually in excess of 30% w/w. Pyrogenic tars and tar products have unique PAH patterns (source signatures) that are a function of their industrial production. Among pyrogenic materials, certain diagnostic ratios of environmentally recalcitrant 4-, 5- and 6-ring PAHs have been identified as useful environmental markers for tracking the signature of tars and petroleum in the environment. The use of selected PAH source ratios is based on the concept that PAHs with similar properties (i.e., molecular weight, partial pressure, solubility, partition coefficients, and biotic/abiotic degradation) will weather at similar rates in the environment thereby yielding stable ratios. The stability of more than 30 high molecular weight PAH ratios is evaluated during controlled studies of tar evaporation and aerobic biodegradation. The starting materials in these experiments consisted of relatively unweathered tars derived from coal and petroleum, respectively. The PAH ratios from these laboratory studies are compared to those measured in PAH residues found in tar-contaminated soils at a former MGP that operated with a carburetted water gas process.

  13. [Food allergies].

    PubMed

    Fuchs, M

    1998-09-21

    Food allergy must have an immunological background. Till recently it was restricted only to the IgE mechanism, today we include also non-atopical reactions (in particular type III and IV according to Coombs and Gell). We speak of probable and possible food allergies. By differential diagnosis we must differentiate food allergies from food intolerance (e.g. enzyme deficiencies), food aversions (psychic factor) as well as toxic and pharmacological effects. There are more than 10% undesirable reactions in humans after ingestion of food but only every fifth (some 2% of the population have food allergies. The diagnosis is based above all on the case-history, subsequent elimination and exposure tests and examination by allergological tests, or examination of specific immunoglobulins E (IgE). The diagnosis is not always unequivocal--it is influenced among others by a different specificity and sensitivity of food antigens (allergens). The manifestations of food allergy are found at the site of action (mouth, GIT) or are systemic (respiration, cardiovascular system, skin etc.). A special type of food allergy is the oral alimentary syndrome, i.e. food allergy crossed with pollen hypersensitivity, described in the great majority of subjects sensitive to pollen. Food allergy has its specific age-conditioned and geographical features. In childhood sensitivity to the protein of cows milk, egg white but also soya or flour predominates, with advancing age allergies to nuts, fruit, vegetables, spices, cheese, sea foods increase. Food allergy can be a very early allergy (manifested already in infant age) but it is one of the few allergies which can also recede (incl. laboratory tests). Treatment is dietetic, the period of dietetic treatment depends on the type of food and the patient's age, not infrequently it must be lifelong. If diet does not suffice, preventive medication is used (sodium cromoglycate) or symptomatic (antihistamine preparations, corticosteroids, external agents

  14. Food Allergies.

    PubMed

    Grief, Samuel N

    2016-09-01

    Food allergies are common and seem to be increasing in prevalence. Preventive measures have become far more evident in the public arena (schools, camps, sports venues, and so forth). Evaluation and management of food allergies has evolved such that primary care practitioners may choose to provide initial diagnostic and treatment care or refer to allergists for similar care. Food allergies, once considered incurable, are now being diminished in intensity by new strategies. PMID:27545729

  15. Plasmids Responsible for Horizontal Transfer of Naphthalene Catabolism Genes between Bacteria at a Coal Tar-Contaminated Site Are Homologous to pDTG1 from Pseudomonas putida NCIB 9816-4

    PubMed Central

    Stuart-Keil, K. G.; Hohnstock, A. M.; Drees, K. P.; Herrick, J. B.; Madsen, E. L.

    1998-01-01

    The presence of a highly conserved nahAc allele among phylogenetically diverse bacteria carrying naphthalene-catabolic plasmids provided evidence for in situ horizontal gene transfer at a coal tar-contaminated site (J. B. Herrick, K. G. Stuart-Keil, W. C. Ghiorse, and E. L. Madsen, Appl. Environ. Microbiol. 63:2330–2337, 1997). The objective of the present study was to identify and characterize the different-sized naphthalene-catabolic plasmids in order to determine the probable mechanism of horizontal transfer of the nahAc gene in situ. Filter matings between naphthalene-degrading bacterial isolates and their cured progeny revealed that the naphthalene-catabolic plasmids were self-transmissible. Limited interstrain transfer was also found. Analysis of the restriction fragment length polymorphism (RFLP) patterns indicated that catabolic plasmids from 12 site-derived isolates were closely related to each other and to the naphthalene-catabolic plasmid (pDTG1) of Pseudomonas putida NCIB 9816-4, which was isolated decades ago in Bangor, Wales. The similarity among all site-derived naphthalene-catabolic plasmids and pDTG1 was confirmed by using the entire pDTG1 plasmid as a probe in Southern hybridizations. Two distinct but similar naphthalene-catabolic plasmids were retrieved directly from the microbial community indigenous to the contaminated site in a filter mating by using a cured, rifampin-resistant site-derived isolate as the recipient. RFLP patterns and Southern hybridization showed that both of these newly retrieved plasmids, like the isolate-derived plasmids, were closely related to pDTG1. These data indicate that a pDTG1-like plasmid is the mobile genetic element responsible for transferring naphthalene-catabolic genes among bacteria in situ. The pervasiveness and persistence of this naphthalene-catabolic plasmid suggest that it may have played a role in the adaptation of this microbial community to the coal tar contamination at our study site. PMID:9758778

  16. Food Allergy.

    PubMed

    Sathe, Shridhar K; Liu, Changqi; Zaffran, Valerie D

    2016-01-01

    Food allergy is receiving increased attention in recent years. Because there is currently no known cure for food allergy, avoiding the offending food is the best defense for sensitive individuals. Type I food allergy is mediated by food proteins, and thus, theoretically, any food protein is a potential allergen. Variability of an individual's immune system further complicates attempts to understand allergen-antibody interaction. In this article, we briefly review food allergy occurrence, prevalence, mechanisms, and detection. Efforts aimed at reducing/eliminating allergens through food processing are discussed. Future research needs are addressed. PMID:26934173

  17. Drug allergies

    MedlinePlus

    Allergic reaction - drug (medication); Drug hypersensitivity; Medication hypersensitivity ... A drug allergy involves an immune response in the body that produces an allergic reaction to a medicine. The ...

  18. Coal: Its Structure and Some of Its Uses.

    ERIC Educational Resources Information Center

    Phillips, P. S.

    1981-01-01

    Describes the formation, chemical structure, and several uses of coal. The history of coal usage, production processes, coal tar products, and production of petroleum and other hydrocarbons from coal are also described. (DS)

  19. Upgrading method of low-rank coal

    SciTech Connect

    Yokoyama, H.; Kuge, T.; Nakamura, Y.; Nogita, Sh.

    1984-07-24

    A coal is finely pulverized. The finely pulverized coal is subjected to dry distillation. A tar obtained by the dry distillation is added to an aqueous slurry together with the dry-distilled coal to effect the submerged granulation.

  20. Egg Allergy

    MedlinePlus

    ... out. If it's not treated, anaphylaxis can be life threatening. Egg allergy usually first shows up when kids are very young. Most kids outgrow an egg allergy by the time they're 5 years old, but some people stay allergic. The viruses for the flu vaccine are grown in chicken ...

  1. 29 CFR 779.357 - May qualify as exempt 13(a)(2) establishments; classification of coal sales.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... principal raw material, such as sales of coal for the production of coke, coal gas, coal tar, or electricity... production of coke, coal gas, coal tar, or electricity. This is distinguished from sales of coal for use in...; classification of coal sales. 779.357 Section 779.357 Labor Regulations Relating to Labor (Continued) WAGE......

  2. 29 CFR 779.357 - May qualify as exempt 13(a)(2) establishments; classification of coal sales.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... principal raw material, such as sales of coal for the production of coke, coal gas, coal tar, or electricity... production of coke, coal gas, coal tar, or electricity. This is distinguished from sales of coal for use in...; classification of coal sales. 779.357 Section 779.357 Labor Regulations Relating to Labor (Continued) WAGE......

  3. 29 CFR 779.357 - May qualify as exempt 13(a)(2) establishments; classification of coal sales.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... principal raw material, such as sales of coal for the production of coke, coal gas, coal tar, or electricity... production of coke, coal gas, coal tar, or electricity. This is distinguished from sales of coal for use in...; classification of coal sales. 779.357 Section 779.357 Labor Regulations Relating to Labor (Continued) WAGE......

  4. 29 CFR 779.357 - May qualify as exempt 13(a)(2) establishments; classification of coal sales.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... principal raw material, such as sales of coal for the production of coke, coal gas, coal tar, or electricity... production of coke, coal gas, coal tar, or electricity. This is distinguished from sales of coal for use in...; classification of coal sales. 779.357 Section 779.357 Labor Regulations Relating to Labor (Continued) WAGE......

  5. Extracting Oil From Tar Sands

    NASA Technical Reports Server (NTRS)

    Ford, L. B.; Daly, D.

    1984-01-01

    Recovery of oil from tar sands possible by batch process, using steam produced by solar heater. In extraction process, solar heater provides steam for heating solvent boiler. Boiling solvent removes oil from tar sands in Soxhlet extractor.

  6. Drug Allergy.

    PubMed

    Waheed, Abdul; Hill, Tiffany; Dhawan, Nidhi

    2016-09-01

    An adverse drug reaction relates to an undesired response to administration of a drug. Type A reactions are common and are predictable to administration, dose response, or interaction with other medications. Type B reactions are uncommon with occurrences that are not predictable. Appropriate diagnosis, classification, and entry into the chart are important to avoid future problems. The diagnosis is made with careful history, physical examination, and possibly allergy testing. It is recommended that help from allergy immunology specialists should be sought where necessary and that routine prescription of Epi pen should be given to patients with multiple allergy syndromes. PMID:27545730

  7. Allergy Testing.

    PubMed

    Tourlas, Konstantinos; Burman, Deepa

    2016-09-01

    Allergic diseases are common in outpatient primary care. Allergy testing can guide management to determine allergy as a cause of symptoms and target therapeutic interventions. This article provides a review of common methods of allergy testing available so that physicians may counsel and refer patients appropriately. Immediate-type hypersensitivity skin tests can be used for airborne allergens, foods, insect stings, and penicillin. Radioallergosorbent testing can be used to evaluate immediate-type hypersensitivity. Delayed-type hypersensitivity or patch-type skin tests are used in patients with suspected contact dermatitis. PMID:27545728

  8. Utilization of acid tars

    SciTech Connect

    Frolov, A.F.; Denisova, T.L.; Aminov, A.N.

    1987-01-01

    Freshly produced acid tar (FPAT), obtained as refinery waste in treating petroleum oils with sulfuric acid and oleum, contains 80% or more sulfuric acid. Of such tars, pond acid tars, which contain up to 80% neutral petroleum products and sulfonated resins, are more stable, and have found applications in the production of binders for paving materials. In this article the authors are presenting results obtained in a study of the composition and reactivity of FPAT and its stability in storage in blends with asphalts obtained in deasphalting operations, and the possibility of using the FPAT in road construction has been examined. In this work, wastes were used which were obtained in treating the oils T-750, KhF-12, I-8A, and MS-14. Data on the change in group chemical composition of FPAT are shown, and the acidity, viscosity, needle penetration, and softening point of acid tars obtained from different grades of oils are plotted as functions of the storage time. It is also shown that the fresh and hardened FPATs differ in their solubilities in various solvents.

  9. Soy Allergy

    MedlinePlus

    ... the word “Soy” on the label. Read all product labels carefully before purchasing and consuming any item. Ingredients ... Getting Started Newly Diagnosed Emergency Care Plan Food Labels Mislabeled Products Tips for Managing Food Allergies Resources For... Most ...

  10. Wheat Allergy

    MedlinePlus

    ... the word “Wheat” on the label. Read all product labels carefully before purchasing and consuming any item. Ingredients ... Getting Started Newly Diagnosed Emergency Care Plan Food Labels Mislabeled Products Tips for Managing Food Allergies Resources For... Most ...

  11. Peanut Allergy

    MedlinePlus

    ... the word “Peanut” on the label. Read all product labels carefully before purchasing and consuming any item. Ingredients ... Getting Started Newly Diagnosed Emergency Care Plan Food Labels Mislabeled Products Tips for Managing Food Allergies Resources For... Most ...

  12. Fish Allergy

    MedlinePlus

    ... specific fish used on the label. Read all product labels carefully before purchasing and consuming any item. Ingredients ... Getting Started Newly Diagnosed Emergency Care Plan Food Labels Mislabeled Products Tips for Managing Food Allergies Resources For... Most ...

  13. Allergy shots

    MedlinePlus

    ... include: Mold spores Dust mites Animal dander Pollen Insect venom A health care provider gives you the ... that allergies make worse Allergic rhinitis, allergic conjunctivitis Insect bite sensitivity Eczema , a skin condition that a ...

  14. Food allergy

    MedlinePlus

    ... people of all ages) Soy (mostly in children) Tree nuts (people of all ages) Wheat (people of ... food when they are young. Allergies to peanuts, tree nuts, and shellfish tend to last a lifetime. ...

  15. Eye Allergies

    MedlinePlus

    ... MD Mar. 01, 2015 Eye allergies, called allergic conjunctivitis , are a common condition that occurs when the ... with tearing and burning. Unlike bacterial or viral conjunctivitis, allergic conjunctivitis is not spread from person to ...

  16. Shellfish Allergy

    MedlinePlus

    ... The two different types of shellfish allergy are: crustaceans (like shrimp, crab, or lobster) mollusks (like clams, ... of the top eight most common allergens, including crustacean shellfish. The label should list "shellfish" in the ...

  17. Shellfish Allergy

    MedlinePlus

    ... fish allergy. Shellfish fall into two different groups: crustaceans (like shrimp, crab, or lobster) and mollusks (like ... shellfish on food labels, they are referring to crustacean shellfish. If you are allergic to mollusks, then ...

  18. Latex allergy.

    PubMed

    Pollart, Susan M; Warniment, Christa; Mori, Takahiro

    2009-12-15

    The prevalence of latex allergy in the general population is low; however, the risk of developing latex allergy is higher in persons with increased latex exposure, such as health care workers or persons who work in the rubber industry. Children with spina bifida and others who undergo multiple surgeries or procedures, particularly within the first year of life, are also at greater risk of latex allergy. Reactions to latex allergy can range from type IV delayed hypersensitivity (e.g., contact dermatitis) to type I immediate hypersensitivity (e.g., urticaria, bronchospasm, anaphylaxis). Latex allergy can be diagnosed with clinical history, skin prick testing, latex-specific serum immunoglobulin E testing, and glove provocation testing. The main goals of latex allergy management are avoidance of exposure to latex allergens and appropriate treatment of allergic reactions. The use of nonlatex products from birth may prevent potentially serious allergic reactions. Widespread adoption of nonlatex or low-latex gloves has decreased the incidence of latex sensitization in health care workers. PMID:20000303

  19. Allergy testing - skin

    MedlinePlus

    Patch tests - allergy; Scratch tests - allergy; Skin tests - allergy; RAST test ... There are three common methods of allergy skin testing. The skin prick test involves: Placing a small amount of substances that may be causing your symptoms on the skin, ...

  20. Asthma and allergy - resources

    MedlinePlus

    Resources - asthma and allergy ... The following organizations are good resources for information on asthma and allergies : Allergy and Asthma Network Mothers of Asthmatics -- www.aanma.org American Academy of Allergy, Asthma ...

  1. Identification and quantification of seven fused aromatic rings C26H14peri-condensed benzenoid polycyclic aromatic hydrocarbons in a complex mixture of polycyclic aromatic hydrocarbons from coal tar.

    PubMed

    Oña-Ruales, Jorge O; Ruiz-Morales, Yosadara; Wise, Stephen A

    2016-04-15

    A methodology for the characterization of groups of polycyclic aromatic hydrocarbons (PAHs) using a combination of normal phase liquid chromatography with ultraviolet-visible spectroscopy (NPLC/UV-vis) and gas chromatography with mass spectrometry (GC/MS) was used for the identification and quantification of seven fused aromatic rings C26H14peri-condensed benzenoid polycyclic aromatic hydrocarbons, PAHs, in standard reference material (SRM) 1597a, complex mixture of PAHs from coal tar. The NPLC/UV-vis isolated the fractions based on the number of aromatic carbons and the GC/MS allowed the identification and quantification of five of the nine C26H14 PAH isomers; naphtho[1,2,3,4-ghi]perylene, dibenzo[b,ghi]perylene, dibenzo[b,pqr]perylene, naphtho[8,1,2-bcd]perylene, and dibenzo[cd,lm]perylene using a retention time comparison with authentic reference standards. For the other four benzenoid isomers with no available reference standards the following two approaches were used. First, the annellation theory was used to achieve the potential identification of benzo[qr]naphtho[3,2,1,8-defg]chrysene, and second, the elution distribution in the GC fractions was used to support the potential identification of benzo[qr]naphtho[3,2,1,8-defg]chrysene and to reach the tentative identifications of dibenzo[a,ghi]perylene, naphtho[7,8,1,2,3-pqrst]pentaphene, and anthra[2,1,9,8-opqra]naphthacene. It is the first time that naphtho[1,2,3,4-ghi]perylene, dibenzo[b,ghi]perylene, dibenzo[b,pqr]perylene, naphtho[8,1,2-bcd]perylene, and dibenzo[cd,lm]perylene are quantified, and the first time that benzo[qr]naphtho[3,2,1,8-defg]chrysene is potentially identified, in any sample, in any context. PMID:26976350

  2. [Implant allergies].

    PubMed

    Thomas, P; Thomsen, M

    2010-03-01

    An increasing number of patients receive and benefit from osteosynthesis materials or artificial joint replacement. The most common complications are mechanical problems or infection. Metals like nickel, chromium and cobalt as well as bone cement components like acrylates and gentamicin are potential contact allergens which can cause intolerance reactions to implants. Eczema, delayed wound/bone healing, recurrent effusions, pain and implant loosening all have been described as manifestation of implant allergy. In contrast to the high incidence of cutaneous metal allergy, allergies associated with implants are rare. Diagnosis of metal implant allergy is still difficult. Thus differential diagnoses--in particular infection--have to be excluded and a combined approach of allergologic diagnostics by patch test and histopathology of peri-implant tissue is recommended. It is still unknown which conditions induce allergic sensitization to implants or trigger peri-implant allergic reactions in the case of preexisting cutaneous metal allergy. Despite the risk of developing complications being unclear, titanium based osteosynthesis materials are recommended for metal allergic patients and the use of metal-metal couplings in arthroplasty is not recommended for such patients. If the regular CoCr-polyethylene articulation is employed, the patient should give informed written consent. PMID:20204719

  3. Coal.

    ERIC Educational Resources Information Center

    Brant, Russell A.; Glass, Gary B.

    1983-01-01

    Principle work of 23 state geological surveys is summarized. Work includes mapping/estimating coal resources, centralizing data in National Coal Resources Data System through cooperative programs, exploration drilling, and others. Comments on U.S. Geological Survey activities, coal-related conferences/meetings, and industry research activities are…

  4. Pollen Allergy

    MedlinePlus

    ... pollen count, which is often reported by local weather broadcasts or allergy websites, is a measure of how much pollen is in the air. Pollen counts tend to be highest early in the morning on warm, dry, breezy days and lowest during chilly, wet periods. ...

  5. Food Allergy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The incidence of food allergy appears to be increasing, as is our understanding of the underlying mechanisms, treatment options, identifying, and characterizing allergenic proteins within food sources. The aim of this book is to translate how this vast array of information may fit into development o...

  6. Cytochrome P450 1b1 in polycyclic aromatic hydrocarbon (PAH)-induced skin carcinogenesis: Tumorigenicity of individual PAHs and coal-tar extract, DNA adduction and expression of select genes in the Cyp1b1 knockout mouse.

    PubMed

    Siddens, Lisbeth K; Bunde, Kristi L; Harper, Tod A; McQuistan, Tammie J; Löhr, Christiane V; Bramer, Lisa M; Waters, Katrina M; Tilton, Susan C; Krueger, Sharon K; Williams, David E; Baird, William M

    2015-09-01

    FVB/N mice wild-type, heterozygous or null for Cyp 1b1 were used in a two-stage skin tumor study comparing PAH, benzo[a]pyrene (BaP), dibenzo[def,p]chrysene (DBC), and coal tar extract (CTE, SRM 1597a). Following 20 weeks of promotion with TPA the Cyp 1b1 null mice, initiated with DBC, exhibited reductions in incidence, multiplicity, and progression. None of these effects were observed with BaP or CTE. The mechanism of Cyp 1b1-dependent alteration of DBC skin carcinogenesis was further investigated by determining expression of select genes in skin from DBC-treated mice 2, 4 and 8h post-initiation. A significant reduction in levels of Cyp 1a1, Nqo1 at 8h and Akr 1c14 mRNA was observed in Cyp 1b1 null (but not wt or het) mice, whereas no impact was observed in Gst a1, Nqo 1 at 2 and 4h or Akr 1c19 at any time point. Cyp 1b1 mRNA was not elevated by DBC. The major covalent DNA adducts, dibenzo[def,p]chrysene-(±)-11,12-dihydrodiol-cis and trans-13,14-epoxide-deoxyadenosine (DBCDE-dA) were quantified by UHPLC-MS/MS 8h post-initiation. Loss of Cyp1 b1 expression reduced DBCDE-dA adducts in the skin but not to a statistically significant degree. The ratio of cis- to trans-DBCDE-dA adducts was higher in the skin than other target tissues such as the spleen, lung and liver (oral dosing). These results document that Cyp 1b1 plays a significant role in bioactivation and carcinogenesis of DBC in a two-stage mouse skin tumor model and that loss of Cyp 1b1 has little impact on tumor response with BaP or CTE as initiators. PMID:26049101

  7. Cytochrome P450 1b1 in polycyclic aromatic hydrocarbon (PAH)-induced skin carcinogenesis: Tumorigenicity of individual PAHs and coal-tar extract, DNA adduction and expression of select genes in the Cyp1b1 knockout mouse

    SciTech Connect

    Siddens, Lisbeth K.; Bunde, Kristi L.; Harper, Tod A.; McQuistan, Tammie J.; Löhr, Christiane V.; Bramer, Lisa M.; Waters, Katrina M.; Tilton, Susan C.; Krueger, Sharon K.; and others

    2015-09-01

    FVB/N mice wild-type, heterozygous or null for Cyp 1b1 were used in a two-stage skin tumor study comparing PAH, benzo[a]pyrene (BaP), dibenzo[def,p]chrysene (DBC), and coal tar extract (CTE, SRM 1597a). Following 20 weeks of promotion with TPA the Cyp 1b1 null mice, initiated with DBC, exhibited reductions in incidence, multiplicity, and progression. None of these effects were observed with BaP or CTE. The mechanism of Cyp 1b1-dependent alteration of DBC skin carcinogenesis was further investigated by determining expression of select genes in skin from DBC-treated mice 2, 4 and 8 h post-initiation. A significant reduction in levels of Cyp 1a1, Nqo1 at 8 h and Akr 1c14 mRNA was observed in Cyp 1b1 null (but not wt or het) mice, whereas no impact was observed in Gst a1, Nqo 1 at 2 and 4 h or Akr 1c19 at any time point. Cyp 1b1 mRNA was not elevated by DBC. The major covalent DNA adducts, dibenzo[def,p]chrysene-(±)-11,12-dihydrodiol-cis and trans-13,14-epoxide-deoxyadenosine (DBCDE-dA) were quantified by UHPLC-MS/MS 8 h post-initiation. Loss of Cyp1 b1 expression reduced DBCDE-dA adducts in the skin but not to a statistically significant degree. The ratio of cis- to trans-DBCDE-dA adducts was higher in the skin than other target tissues such as the spleen, lung and liver (oral dosing). These results document that Cyp 1b1 plays a significant role in bioactivation and carcinogenesis of DBC in a two-stage mouse skin tumor model and that loss of Cyp 1b1 has little impact on tumor response with BaP or CTE as initiators. - Highlights: • Cyp1b1 null mice exhibit lower skin cancer sensitivity to DBC but not BaP or CTE. • Cyp1b1 expression impacts expression of other PAH metabolizing enzymes. • cis/trans-DBCDE-dA ratio significantly higher in the skin than the spleen, lung or liver • Potency of DBC and CTE in mouse skin is higher than predicted by RPFs.

  8. Allergy-Friendly Gardening

    MedlinePlus

    ... Allergy Library ▸ Allergy-friendly gardening Share | Allergy-Friendly Gardening This article has been reviewed by Thanai Pongdee, ... of pollen spores that you breathe in. Leave gardening tools and clothing (such as gloves and shoes) ...

  9. Allergies, asthma, and dust

    MedlinePlus

    Allergic rhinitis - dust ... make allergies or asthma worse are called triggers. Dust is a common trigger. When your asthma or allergies become worse due to dust, you are said to have a dust allergy. ...

  10. Allergy testing - skin

    MedlinePlus

    ... if you are allergic to bee venom or penicillin. Or it may be used if the skin ... sore, or swollen after contact with the substance Penicillin allergy Venom allergy Allergies to penicillin and closely ...

  11. Allergies, asthma, and molds

    MedlinePlus

    Allergic rhinitis - mold ... make allergies or asthma worse are called triggers. Mold is a common trigger. When your asthma or allergies become worse due to mold, you are said to have a mold allergy. ...

  12. [Latex allergy].

    PubMed

    Bayrou, Olivier

    2006-02-15

    Immediate hypersensitivity to natural rubber latex has increased since the early 1980s. High prevalence of latex sensitization and allergy are observed among healthcare workers, atopic individuals and children who had undergone multiple surgical operations (spina bifida, congenital anomalies). Presenting symptoms are polymorphous: contact urticaria, rhinitis, conjunctivitis, asthma, and anaphylaxis. Corn-starch-latex particles released in the air after powdered gloves manipulation may be inhaled and lead to occupational asthma. The diagnosis may be made by a focused clinical history, prick-test, detection of specific IgE antibody and challenge test. Almost half of patients allergic to natural rubber latex show an associated fruit allergy: avocado, banana, kiwi, chestnut. Most of cutaneous delayed reactions (eczema) to rubber are caused by rubber additives (accelerators of vulcanization, anti-oxidants). PMID:16583955

  13. Latex allergies - for hospital patients

    MedlinePlus

    ... Allergy Association; American College of Allergy, Asthma and Immunology. Latex Cross-reactive Foods Fact Sheet. Updated October ... Allergy Association; American College of Allergy, Asthma and Immunology. Guidelines for the Management of Latex Allergies. Updated ...

  14. Managing latex allergies at home

    MedlinePlus

    ... Allergy Association; American College of Allergy, Asthma and Immunology. Latex Cross-reactive Foods Fact Sheet. Updated October ... Allergy Association; American College of Allergy, Asthma and Immunology. Guidelines for the Management of Latex Allergies. Updated ...

  15. Physical allergies.

    PubMed

    Horan, R F; Sheffer, A L; Briner, W W

    1992-08-01

    Allergic responses that occur as a result of exposure to physical stimuli are discussed. Most of these conditions are mediated by vasoactive substances, resulting in urticaria and/or angioedema. Susceptible individuals who engage in athletic activities may place themselves at particular risk for these problems. The physical allergies include cholinergic urticaria, exercise-induced anaphylaxis, cold urticaria, dermatographism, solar urticaria, and aquagenic urticaria. Management of these conditions includes patient education, selective avoidance, antihistamines, and, in some cases, induction of tolerance. PMID:1406166

  16. [Latex allergy].

    PubMed

    Richter, J; Susický, P

    2000-04-01

    The authors describe a case of an allergic affection in a patient with occupational exposure to latex allergens with a history of anaphylactic reaction to poppy seed and reaction to the antigens of apples, oranges, tangerines, peanuts and bananas, revealed by the method CAP Phadiatop. A marked reaction was initiated after the use of a shampoo containing volatile banana oil. The authors emphasize the high incidence of latex allergy, the manifestations of which may be encountered also in clinical ophthalmology. PMID:10874793

  17. Egg allergy.

    PubMed

    Kemp, Andrew S

    2007-12-01

    Egg allergy is one of the most common food allergies in infants and young children. The great majority is not life-threatening and management involves exclusion of egg from the diet and regular review with the expectation that the majority of children will outgrow the allergy by school age. Judgment is required as to when the dietary elimination of egg is no longer required. This decision may be helped by demonstrating loss of sensitivity by skin prick or specific IgE testing and in some cases a supervised food challenge. Particular issues in management arise with more severe, potentially life-threatening reactions, with immunization with vaccines prepared in eggs, with the diagnosis of egg hypersensitivity as a cause of delayed exacerbations of eczema which can be non-IgE mediated, and in deciding whether a child can be allowed to ingest small amounts of cooked egg through egg-containing foods while continuing to avoid raw egg or larger amounts of whole egg. Cases which illustrate these issues are presented. PMID:18078424

  18. Skin Allergy Quiz

    MedlinePlus

    American Academy of Allergy Asthma & Immunology Menu Search Main navigation Skip to content Conditions & Treatments Allergies Asthma Primary Immunodeficiency Disease Related Conditions Drug Guide Conditions Dictionary Just ...

  19. Task 3.9 -- Catalytic tar cracking. Semi-annual report, January 1--June 30, 1995

    SciTech Connect

    Young, B.C.; Timpe, R.C.

    1995-12-31

    Tar produced in the gasification of coal is deleterious to the operation of downstream equipment including fuel cells, gas turbines, hot-gas stream cleanup filters, and pressure swing adsorption systems. Catalytic cracking of tars to smaller hydrocarbons can be an effective means to remove these tars from gas streams and, in the process, generate useful products, e.g., methane gas, which is crucial to the operation of molten carbonate fuel cells. The objectives of this project are to investigate whether gasification tars can be cracked by synthetic nickel-substituted micamontmorillonite, zeolite, or dolomite material; and whether the tars can be cracked selectively by these catalysts to produce a desired liquid and/or gas stream. Results to date are presented in the cited papers.

  20. Drying low rank coal and retarding spontaneous ignition

    SciTech Connect

    Bellow, E.J. Jr.; Bixel, J.C.; Heaney, W.F.; Yan, T.Y.

    1989-05-09

    A method is described of passivating and cooling heated dried coal comprising: (a) heating particulate coal to a temperature between about 190 and about 230/sup 0/F to dry to the desired level: and (b) coating the resulting heated particulate coal with an aqueous emulsion of a hydrocarbon selected from the group consisting of petroleum resid, light cycle oil, heavy cycle oil, clarified slurry oil, durene, asphaltenes, coal tar and coal tar pitch.

  1. Relationship Between the Composition and Interfacial Tension of Former Manufactured Gas Plant Tars

    NASA Astrophysics Data System (ADS)

    Hauswirth, S.; Birak, P. S.; Miller, C. T.

    2011-12-01

    Former manufactured gas plant (FMGP) tars pose significant environmental hazards and present a challenge to regulators and industry professionals. The tars, which were produced as a byproduct of the gas manufacturing process, were frequently released into the environment through improper disposal or leaks in plant infrastructure. The interfacial tension (IFT) is a primary factor controlling the mobility of tars in porous media, and is therefore important to understand for both predicting the migration of tars and designing remediation strategies. In this study, we characterized nine field-collected FMGP tars and a commercially available coal tar by means of chemical extractions (asphaltenes, resins, acids, and bases), gas chromatography-mass spectrometry (GC-MS), and Fourier transform infrared (FTIR) spectroscopy. Additionally, the IFT and contact angle of each tar was determined for a pH range of 3-11. The IFT was found to be similar for all tars at pH 5 and 7 regardless of composition. Slight decreases in IFT at lower pH were correlated with higher concentrations of extractable bases, which consisted primarily of nitrogen-containing heterocyclic aromatic compounds. Much greater reductions of IFT were observed at high pH. These reductions were found to be associated with the presence of carbonyl or carboxyl groups in the asphaltenes. It is likely that the larger size of the asphaltene molecules (as compared to the extractable compounds) resulted in species with greater surface activity when ionized.

  2. Plant response to aqueous effluents derived from in-situ fossil-fuel processing. Part III. Three grass species and their response to Omega 9 and to five produced retort waters: oil shale, tar sands and underground coal gasification. [Basin wildrye; western wheatgrass; alkali sacaton

    SciTech Connect

    Skinner, Q.D.

    1981-12-01

    In situ produced waters collected from retorting oil shale and tar sands to produce oil and in-situ coal gasification to produce gas were tested for their effect on plant growth. Three native grass plant species were utilized for monitoring growth response. Root weight, shoot weight, total dry weight, leaf area, root/shoot ratio and shoot/leaf area ratio were parameters measured. All experiments were conducted under greenhouse conditions using hydroponic techniques and commercial grade perlite as support systems. Measurements were collected after a 10-week growth period. The hypothesis tested was, there is a difference between produced waters diluted by ground water and those where dilution is non-existent and their effect on plant growth. Results indicated that retort water diluted by ground water has a less toxic effect on plant species tested.

  3. Plant response to aqueous effluents derived from in-situ fossil-fuel processing. Part II. Five grass plant species and their response to five produced retort waters: oil shale, tar sands, and underground coal gasification. [Wildrye; wheatgrass; alkali sacaton; alkaligrass

    SciTech Connect

    Skinner, Q.D.

    1981-11-01

    In situ produced waters collected from retorting oil shale and tar sands to produce oil and in-situ coal gasification to produce gas were tested for their effect on plant growth. Five native grass plant species were utilized for monitoring growth response. Root weight, shoot weight, total dry weight, leaf area, root/shoot ratio and shoot/leaf area ratio were parameters measured. All experiments were conducted under greenhouse conditions using hydroponic techniques and commercial grade perlite as support systems. Measurements were collected after a 10 week growth period. Hypotheses tested were: (a) there is a difference between in situ produced waters, and (b) plant species respond differently to various retort waters. Results indicated that the stated hypotheses were true.

  4. Allergy prevention.

    PubMed

    Muche-Borowski, Cathleen; Kopp, Matthias; Reese, Imke; Sitter, Helmut; Werfel, Thomas; Schäfer, Torsten

    2010-09-01

    The further increase of allergies in industrialized countries demands evidence-based measures of primary prevention. The recommendations as published in the guideline of 2004 were updated and consented on the basis of a systematic literature search. Evidence from the period February 2003-May 2008 was searched in the electronic databases Cochrane and MEDLINE as well as in reference lists of recent reviews and by contacting experts. The retrieved citations were screened for relevance first by title and abstract and in a second step as full paper. Levels of evidence were assigned to each included study and the methodological quality of the studies was assessed as high or low. Finally the revised recommendations were formally consented (nominal group process) by representatives of relevant societies and organizations including a self-help group. Of originally 4556 hits, 217 studies (4 Cochrane Reviews, 14 meta-analyses, 19 randomized controlled trials, 135 cohort and 45 case-control studies) were included and critically appraised. Grossly unchanged remained the recommendations on avoiding environmental tobacco smoke, breast-feeding over 4 months (alternatively hypoallergenic formulas for children at risk), avoiding a mold-promoting indoor climate, vaccination according to current recommendations, and avoidance of furry pets (especially cats) in children at risk. The recommendation on reducing the house dust mite allergen exposure as a measure of primary prevention was omitted and the impact of a delayed introduction of supplementary food was reduced. New recommendations were adopted concerning fish consumption (during pregnancy / breast-feeding and as supplementary food in the first year), avoidance of overweight, and reducing the exposure to indoor and outdoor air pollutants. The revision of this guideline on a profound evidence basis led to (1) a confirmation of existing recommendations, (2) substantial revisions, and (3) new recommendations. Thereby it is possible

  5. Spectroscopic characterization of visbreaking tars

    SciTech Connect

    Scotti, R.; Clericuzio, M.; Pirovano, C.

    1995-12-31

    The stability of visbreaking tars (VB-tar) constitutes a limit for converting petroleum residues into distillates. Depending on the severity of the process (temperature and/or residence time), a progressive thermal dealkylation of asphaltene molecules occurs, resulting in an increase of aromaticity. As a consequence asphaltenes are hardly maintained in stable suspensions and tend to separate. In the present work VB-tars (350{degrees}C+ and 500{degrees}C+) with different degrees of stability were produced in a continuous bench-scale plant under isothermal conditions (442{degrees}C) with different residence times. The VB-tars were investigated by: (1) NIR and FT-IR to detect the functional groups, (2) UV-VIS and Fluorescence spectroscopies to follow the evolution of aromatic components of the ters, (3) {sup 1}H- and {sup 13}C-NMR to quantify the aromatic content, the degree of substitution of aromatic carbons and the main length of the aliphatic side chains, (4) EPR to study the nature and the amount of radicals. The results of structural investigation and their relations to VB-tar stability will be critically discussed.

  6. Allergies and Headache

    MedlinePlus

    ... vasoactive or neuroactive amino acids such as tyramine , dopamine, phenylethylamine or monosodium glutamate that can trigger a ... Headache Fact Sheets Tags: allergy , allergy and headache , dopamine , headache , migraine , sinus headache , tyramine More Posts ← Tension- ...

  7. Managing Allergies, Asthma 101

    MedlinePlus

    ... gov/medlineplus/news/fullstory_158635.html Managing Allergies, Asthma 101 Doctor offers advice to students who will ... 3, 2016 (HealthDay News) -- Teens with allergies or asthma who are heading for college later this year ...

  8. Vaccines for allergy

    PubMed Central

    Linhart, Birgit; Valenta, Rudolf

    2012-01-01

    Vaccines aim to establish or strengthen immune responses but are also effective for the treatment of allergy. The latter is surprising because allergy represents a hyper-immune response based on immunoglobulin E production against harmless environmental antigens, i.e., allergens. Nevertheless, vaccination with allergens, termed allergen-specific immunotherapy is the only disease-modifying therapy of allergy with long-lasting effects. New forms of allergy diagnosis and allergy vaccines based on recombinant allergen-derivatives, peptides and allergen genes have emerged through molecular allergen characterization. The molecular allergy vaccines allow sophisticated targeting of the immune system and may eliminate side effects which so far have limited the use of traditional allergen extract-based vaccines. Successful clinical trials performed with the new vaccines indicate that broad allergy vaccination is on the horizon and may help to control the allergy pandemic. PMID:22521141

  9. Kids with Food Allergies

    MedlinePlus

    ... Diagnosed Real Families Faces of Food Allergies Rising Stars Gracie's Silver Linings Daniel's Confidence Ciara Builds a ... all recall alerts See all recent news Rising Stars Life As a Tween with Food Allergies MEET ...

  10. Learning about Allergies

    MedlinePlus

    ... Well, you and your dad may have allergies. Chain Reaction An allergy (say: al -ur-jee) is your immune system's reaction to certain plants, animals, foods, insect bites , or other things. Your immune system ...