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1

[Polycyclic aromatic hydrocarbons content in Antarctica soils as exemplified by the Russian polar stations].  

PubMed

The comprehensive study of the qualitative and quantitative composition of polycyclic aromatic hydrocarbons (PAHs) in soils of Antarctica (reference landscapes--mountains Hudson, Haswell Archipelago contaminated soil--Mirny, Druznaya-4, Bellingshausen--and imported soils) was performed with the use of HPLC in a gradient mode. A characteristic feature of the studied PAHs content of soils is the predominance of low-molecular polyarenes in them. Due to anthropogenic pollution the quantitative accumulation of both light and heavy PAHs occurs under the qualitative increase in the proportion of heavy polyarenes. Polyarenes pool in the studied soils is represented mainly by light PAHs: naphthalene, phenanthrene, fluoranthene, pyrene, etc. The content of benzo(a)pyrene does not exceed the MCL (adopted in the Russian Federation) for this ecotoxicant. Performed primary factual and statistical analysis of data permitted to reveal that heavy PAH pollution of Antarctica soils is in the most initial stage, there is no sustained and statistically significant accumulation of PAHs in soils of maritime as well as continental Antarctica. There are established the levels of the actual content of various PAHs in soils of different regions of the Antarctica, which is the basic data for further comparative analysis of data of geochemical studies. PMID:24749277

Abakumov, E V; Lodygin, E D; Gabov, D A; Krylenkov, V A

2014-01-01

2

Polycyclic Aromatic Hydrocarbons  

NSDL National Science Digital Library

The featured molecules for the month of February are a number of polycyclic aromatic hydrocarbons (PAHs) discussed in the article "Fluorescence, Absorption, and Excitation Spectra of Polycyclic Aromatic Hydrocarbons as a Tool for Quantitative Analysis". PAHs are ubiquitous in air, soils, and water as a result of both direct and indirect emissions. PAHs are discharged into environments as byproducts of the combusion of fossil fuels used for transportation and generation of electricity. Other sources of PAH emissions include industrial processes, biomass burning, waste incineration, oil spills, and cigarette smoke.

3

Influence of Agricultural Land Use and Management on the Contents of Polycyclic Aromatic Hydrocarbons in Selected Silty Soils  

Microsoft Academic Search

The aim of the present study was the influence of various methods of long-term soil utilisation on the content of polycyclic\\u000a aromatic hydrocarbons (PAH) in selected silty soils. Four soils were selected for the present studies, i.e.: Eutric Fluvisol originating from silty formations, Haplic Phaeozem developed from loess, Haplic Luvisol (non-uniform) developed from silt, Haplic Luvisol developed from loess. Five

Patryk Oleszczuk; Jacek Pranagal

2007-01-01

4

[Content analysis and assessment of polycyclic aromatic hydrocarbons in surface sediments from Beijiang River, China].  

PubMed

In the present study, 16 polycyclic aromatic hydrocarbons (PAHs) in the surface sediment from Beijiang River in China were quantitatively determined by GC/MS. The concentration of PAHs varied from 38.2 to 6470 ng x g(-1) dry weight, with average 1071 ng x g(-1), which was in moderate level compared with other rivers in Pear River Basin. The PAHs distribution in Bejiang River was obviously affected by point source emissions. The high PAHs concentrations of 6470 ng x g(-1) and 4 470 ng x g(-1) were found at the outfalls of Shaoye and the Shakou town, respectively, where PAHs probably derived from local mining/smelting and related industrial actives. The ecological risk of surface sediment in Beijiang River was assessed with the methods of sediment quality guidelines (SQGs), sediment quality standards (SQSs) and contamination factors (CFs) . The result shows that the adverse biological toxicity effect might occasionally happen in more than half of sampling stations. By comparison with the background area, the contamination degrees of PAHs in 20 sampling stations were at very high level, which should arrest the local governments' attentions. The highest ecological risk areas occurred at the outfalls of Shaoye and the Shakou town in which the ecological risks derived from PAHs were within between probable effect level (PEL) and frequent effect level (FEL). The future research was suggested mainly focusing on the status of benthos, sources of pollutants and ways to control pollution in high-risk areas. PMID:20063739

Xu, Jing; Ren, Ming-Zhong; Du, Gou-Yong; Zhang, Su-Kun; Xu, Zhen-Cheng

2009-11-01

5

AROMATIC HYDROCARBON DEGRADATION: A MOLECULAR APPROACH  

EPA Science Inventory

Aromatic hydrocarbons have a ubiquitous distribution in nature. he majority of these compounds are formed through the pyrolysis of organic matter. yrolysis at high temperatures leads to the information of unsubstituted polycyclic aromatic hydrocarbons (1). yrolysis at low tempera...

6

PHOTOREACTIVITY OF SELECTED AROMATIC HYDROCARBONS IN WATER  

EPA Science Inventory

Quantitative data concerning photoreactions of aromatic hydrocarbons were obtained in distilled water and several natural water samples. The reactions were studied at concentrations lower than the solubility limits of the aromatics, which in some cases were less than 1 microgram ...

7

Aromatic excimers: evidence for polynuclear aromatic hydrocarbon condensation in flames  

Microsoft Academic Search

A new assignment for the broad band visible laser induced fluorescence observed in rich hydrocarbon flames is offered. It is postulated that emission from aromatic excimers is observed when exciting aromatic aggregates in flames. Because this emission will only occur when the aromatic molecular units are near one another, this assignment would provide evidence for agglomeration of modestly sized polynuclear

J. Houston Miller

2005-01-01

8

Polycyclic aromatic hydrocarbons in foundries.  

PubMed

Air and dust samples from iron foundries were analyzed for polycyclic aromatic hydrocarbons (PAH) by glass capillary gas chromatography, mass spectrometry, and thin-layer chromatography. Fifty compounds were identified as PAH, among them known carcinogens and cocarcinogens. Benzo[a]pyrene (B[a]P) was measured quantitatively. The results were grouped according to the types of organic additives in the molding sand. The B[a]P concentrations were highest in foundries using coal tar pitch and in the work phases of shake-out, casting, and molding. In the Ames assay the dust samples showed mutagenic activity, but in most cases lower than that calculated from the concentration of B[a]P. It is suggested that B[a]P can be used as a hygienic marker in branches of industry with PAH problems. PMID:7463509

Schimberg, R W; Pfäffli, P; Tossavainen, A

1980-01-01

9

Infrared Spectra of Polycyclic Aromatic Hydrocarbons (PAHs)  

NASA Technical Reports Server (NTRS)

We have computed the synthetic infrared spectra of some polycyclic aromatic hydrocarbons containing up to 54 carbon atoms. The species studied include ovalene, circumcoronene, dicoronylene, and hexabenzocoronene. We report spectra for anions, neutrals, cations, and multiply charged cations.

Bauschlicher, Charles W., Jr.; Bakes, E. L. O.

2000-01-01

10

Liquid electrostatic developers containing aromatic hydrocarbons  

SciTech Connect

A liquid electrostatic developer is described having improved charging characteristics consisting essentially of nonpolar liquid having a Kauri-butanol value of less than 30, thermoplastic resin particles substantially nonsoluble in nonpolar liquid and aromatic hydrocarbon at ambient temperature and having an average by area particle size of less than 10 is contained inm, nonpolar liquid soluble ionic or zwitterionic compound, and aromatic hydrocarbon having a Kauri-butanol value of greater than 30.

Mitchell, R.D.

1987-05-05

11

Mutagenicity (micronucleus test in Vicia faba root tips), polycyclic aromatic hydrocarbons and heavy metal content of sediments collected in Tiber river and its tributaries within the urban area of Rome  

Microsoft Academic Search

Sediments collected in Tiber river and in its main tributary water courses within the urban area of Rome were tested for mutagenicity by means of Vicia faba root tips micronucleus (MN) test. Representative samples were scored for micronucleus generating events (chromosome\\/chromatid loss and fragments) too. Sediments were assayed for content of the thirteen most important chemicals of polycyclic aromatic hydrocarbon

Sandra Minissi; Daniela Caccese; Fabio Passafiume; Angiolina Grella; Eleonora Ciccotti; Marco Rizzoni

1998-01-01

12

OBSERVATION OF INDIGENOUS POLYCYCLIC AROMATIC HYDROCARBONS IN `GIANT' CARBONACEOUS ANTARCTIC  

E-print Network

. No evidence of contamination whilst in the Antarctic environment could be found. The dramatic variationOBSERVATION OF INDIGENOUS POLYCYCLIC AROMATIC HYDROCARBONS IN `GIANT' CARBONACEOUS ANTARCTIC aromatic hydrocarbons (PAHs) in fragments of fifteen `giant' (200 m) carbonaceous Antarctic micrometeorites

Zare, Richard N.

13

Decreased Mitochondrial DNA Content in Association with Exposure to Polycyclic Aromatic Hydrocarbons in House Dust during Wintertime: From a Population Enquiry to Cell Culture  

PubMed Central

Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental pollutants that are formed in combustion processes. At the cellular level, exposure to PAHs causes oxidative stress and/or some of it congeners bind to DNA, which may interact with mitochondrial function. However, the influence of these pollutants on mitochondrial DNA (mtDNA) content remains largely unknown. We determined whether indoor exposure to PAHs is associated with mitochondrial damage as represented by blood mtDNA content. Blood mtDNA content (ratio mitochondrial/nuclear DNA copy number) was determined by real-time qPCR in 46 persons, both in winter and summer. Indoor PAH exposure was estimated by measuring PAHs in sedimented house dust, including 6 volatile PAHs and 8 non-volatile PAHs. Biomarkers of oxidative stress at the level of DNA and lipid peroxidation were measured. In addition to the epidemiologic enquiry, we exposed human TK6 cells during 24 h at various concentrations (range: 0 to 500 µM) of benzo(a)pyrene and determined mtDNA content. Mean blood mtDNA content averaged (±SD) 0.95±0.185. The median PAH content amounted 554.1 ng/g dust (25th–75th percentile: 390.7–767.3) and 1385ng/g dust (25th–75th percentile: 1000–1980) in winter for volatile and non-volatile PAHs respectively. Independent for gender, age, BMI and the consumption of grilled meat or fish, blood mtDNA content decreased by 9.85% (95% CI: ?15.16 to ?4.2; p?=?0.002) for each doubling of non-volatile PAH content in the house dust in winter. The corresponding estimate for volatile PAHs was ?7.3% (95% CI: ?13.71 to ?0.42; p?=?0.04). Measurements of oxidative stress were not correlated with PAH exposure. During summer months no association was found between mtDNA content and PAH concentration. The ability of benzo(a)pyrene (range 0 µM to 500 µM) to lower mtDNA content was confirmed in vitro in human TK6 cells. Based on these findings, mtDNA content can be a target of PAH toxicity in humans. PMID:23658810

Pieters, Nicky; Koppen, Gudrun; Smeets, Karen; Napierska, Dorota; Plusquin, Michelle; De Prins, Sofie; Van De Weghe, Hendrik; Nelen, Vera; Cox, Bianca; Cuypers, Ann; Hoet, Peter; Schoeters, Greet; Nawrot, Tim S.

2013-01-01

14

Polycyclic Aromatic Hydrocarbon Biodegradation Rates: A  

E-print Network

-15). Several studies of PAHs in crude oils have shown similar trends; degradation rates structure in determining the biodegradation rates of polycyclic aromatic hydrocarbons (PAHs). Laboratory-chemical processes. An aerobic mixed culture was used, which had been enriched on a broad range of PAHs. The 22 PAHs

Peters, Catherine A.

15

IMMUNOCHEMICAL DETECTION OF POLYCYCLIC AROMATIC HYDROCARBONS (PAHs)  

Microsoft Academic Search

This review gives a short introduction in the origin, occurrence and detection of polycyclic aromatic hydrocarbons (PAHs). Emphasis lies on immunochemical detection methods for PAH compounds, such as ELISA, RIA, fluoroimmunosensors, QCM immunosensors and electrochemical immunosensors, but also on immunosorbents and commercial immunoassay kits for PAHs. Possibilities and limitations of these methods compared to standard methods, such as HPLC and

Karsten A. Fähnrich; Miloslav Pravda; George G. Guilbault

2002-01-01

16

Dihydrodiol dehydrogenase and polycyclic aromatic hydrocarbon metabolism  

SciTech Connect

Carcinogenic activation of polycyclic aromatic hydrocarbons by microsomal monoxygenases proceeds through trans-dihydrodiol metabolites to diol-epoxide ultimate carcinogens. This thesis directly investigated the role of dihydrodiol dehydrogenase, a cytosolic NAD(P)-linked oxidoreductase, in the detoxification of polycyclic aromatic trans-dihydrodiols. A wide variety of non-K-region trans-dihydrodiols were synthesized and shown to be substrates for the homogeneous rat liver dehydrogenase, including several potent proximate carcinogens derived from 7,12-dimethylbenz(a)anthracene, 5-methylchrysene, and benzo(a)pyrene. Since microsomal activation of polycyclic aromatic hydrocarbons is highly stereospecific, the stereochemical course of enzymatic trans-dihydrodiol oxidation was monitored using circular dichroism spectropolarimetry. The major product formed from the dehydrogenase-catalyzed oxidation of the trans-1,2-dihydrodiol of naphthalene was characterized using UV, IR, NMR, and mass spectroscopy, and appears to be 4-hydroxy-1,2-naphthoquinone. Mass spectral analysis suggests that an analogous hydroxylated o-quinone is formed as the major product of benzo(a)pyrene-7,8-dihydrodiol oxidation. Enzymatic oxidation of trans-dihydrodiols was shown to be potently inhibited by all of the major classes of the nonsteroidal antiinflammatory drugs. Enhancement of trans-dihydrodiol proximate carcinogen oxidation may protect against possible adverse effects of the aspirin-like drugs, and help maintain the balance between activation and detoxification of polycyclic aromatic hydrocarbons.

Smithgall, T.E.

1986-01-01

17

Arenium acid catalyzed deuteration of aromatic hydrocarbons.  

PubMed

The arenium acid [mesitylene-H](+) has been shown to be an extraordinarily active H/D exchange catalyst for the perdeuteration of polycyclic aromatic hydrocarbons. The reactions take place under ambient conditions in C6D6 as an inexpensive deuterium source. High isolated yields and excellent degrees of deuterium incorporation were achieved using the substrates p-terphenyl, fluoranthene, pyrene, triphenylene, and corannulene. PMID:23163918

Duttwyler, Simon; Butterfield, Anna M; Siegel, Jay S

2013-03-01

18

Black tattoo inks induce reactive oxygen species production correlating with aggregation of pigment nanoparticles and product brand but not with the polycyclic aromatic hydrocarbon content.  

PubMed

Black tattoo inks are composed of carbon nanoparticles, additives and water and may contain polycyclic aromatic hydrocarbons (PAHs). We aimed to clarify whether reactive oxygen species (ROS) induced by black inks in vitro is related to pigment chemistry, physico-chemical properties of the ink particles and the content of chemical additives and contaminants including PAHs. The study included nine brands of tattoo inks of six colours each (black, red, yellow, blue, green and white) and two additional black inks of different brands (n = 56). The ROS formation potential was determined by the dichlorofluorescein (DCFH) assay. A semiquantitative method was developed for screening extractable organic compounds in tattoo ink based on gas chromatography-mass spectrometry (GC-MS) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Two black inks produced high amounts of ROS. Peroxyl radicals accounted for up to 72% of the free radicals generated, whereas hydroxyl radicals and H?O? accounted for <14% and 16%, respectively. The same two inks aggregated strongly in water in contrast to the other black inks. They did not exhibit any shared pattern in PAHs and other organic substances. Aggregation was exclusively shared by all ink colours belonging to the same two brands. Ten of 11 black inks had PAH concentrations exceeding the European Council's recommended level, and all 11 exceeded the recommended level for benzo(a)pyrene. It is a new finding that aggregation of tattoo pigment particles correlates with ROS production and brand, independently of chemical composition including PAHs. ROS is hypothesized to be implicated in minor clinical symptoms. PMID:23800057

Høgsberg, Trine; Jacobsen, Nicklas Raun; Clausen, Per Axel; Serup, Jørgen

2013-07-01

19

QUANTITATIVE ANALYSIS OF POLYNUCLEAR AROMATIC HYDROCARBONS IN LIQUID FUELS  

EPA Science Inventory

Polynuclear aromatic hydrocarbons (PNAs), formed in combustion processes with liquid hydrocarbon fuels, contribute to mobile source exhaust emissions. Because correlation between PNA levels in automobile exhaust and pre-existent PNAs in fuel has been demonstrated in previous work...

20

TRACE ANALYSIS FOR AROMATIC HYDROCARBONS IN NATURAL WATERS  

EPA Science Inventory

A method of trace analysis of volatile aromatic hydrocarbons in natural water is described. The method is based on sparging water samples with nitrogen, adsorption of hydrocarbons on activated charcoal, followed by desorption into carbon disulfide and gas chromatographic analysis...

21

THE UPTAKE OF AROMATIC AND BRANCHED CHAIN HYDROCARBONS BY YEAST  

EPA Science Inventory

Studies of the hydrocarbon utilizing yeasts, Candida maltosa and C. lipolytica, have shown that both were capable of reducing recoverable amounts of branched chain and aromatic hydrocarbons in a mixture of naphthalene, tetradecane, hexadecane, pristane (tetra-methylpentadecane). ...

22

AROMATIC AND POLYCYCLIC AROMATIC HYDROCARBON FORMATION IN A LAMINAR PREMIXED N-BUTANE FLAME. (R825412)  

EPA Science Inventory

Abstract Experimental and detailed chemical kinetic modeling work has been performed to investigate aromatic and polycyclic aromatic hydrocarbon (PAH) formation pathways in a premixed, rich, sooting, n -butane¯oxygen¯argon burner s...

23

POLYCYCLIC AROMATIC HYDROCARBONS IN STORMWATER RUNOFF FROM SEALCOATED  

E-print Network

POLYCYCLIC AROMATIC HYDROCARBONS IN STORMWATER RUNOFF FROM SEALCOATED PAVEMENTS Alison W. Watts-based (asphalt resin, ball clay, silica) · Coal tar-based (coal tar, ball clay) #12;Why do we care? Coal tar;Polycyclic Aromatic Hydrocarbons (PAHs) EPA Priority pollutants Very commonly associated with impaired

24

Polycyclic aromatic hydrocarbons in bovine lens.  

PubMed

A study was performed to detect the presence of polycyclic aromatic hydrocarbons (PAHs) in bovine eyes. Twenty fresh bovine eyes were used to detect the presence of PAHs in lens, vitreous and aqueous by HPLC and spectrofluorometer. In lenticular tissue the mean amount of PAHs was 0.0271 microgram/g and the mean level of PAH in each lens was 0.059 microgram. Five types of PAHs (pyrene, fluoranthene, triphenylene, 1.2-benzanthracene and chrysene) were found in the lenses but none in vitreous and aqueous. These data indicate that PAHs are present only in the lens of the bovine eye. The source of these substances in mammalian clear lens is unclear. PMID:9211470

Gallenga, P E; Morgante, A; Ciancaglini, M; Petti, L; Costagliola, C; Carpineto, P; Mastropasqua, L

1997-01-01

25

Polycyclic aromatic hydrocarbons and cancer in man  

SciTech Connect

Various substances and industrial processes, surrogates of exposure to polycyclic aromatic hydrocarbons (PAHs), are currently classified as human carcinogens. This paper reviews recent epidemiological studies reporting direct evidence of the carcinogenic effects of PAHs in occupationally exposed subjects. Risks of lung and bladder cancer were dose dependent when PAHs were measured quantitatively and truly nonexposed groups were chosen for comparison. These new findings suggest that the current threshold limit value of 0.2 mg/m{sup 3} of benzene soluble matter (which indicates PAH exposure) is unacceptable because, after 40 years of exposure, it involves a relative risk of 1.2-1.4 for lung cancer and 2.2 for bladder cancer. 33 refs., 2 tabs.

Mastrangelo, G.; Marzia, V. [Univ. of Padova (Italy); Fadda, E. [Consorzio Padova Ricerche (Italy)

1996-11-01

26

Aliphatic and aromatic hydrocarbons in coastal Caspian Sea sediments.  

PubMed

This investigation represents the first extensive study of the spatial distribution and sources of aliphatic (n-alkanes and unresolved complex mixture of fossil hydrocarbons) and polycyclic aromatic hydrocarbons (PAHs) in coastal sediments from the Caspian Sea. PAH concentrations, n-alkanes and biomarker profiles all suggested that there was limited petrogenic contamination in the shallow North Caspian Sea sediments, which are coarse with a low total organic carbon content. In contrast, moderate to high petrogenic contamination was found in the South Caspian Sea, in particular in the offshore oil fields near Baku, Azerbaijan. Contaminant patterns indicated that the PAHs were mainly from fossil sources, with higher contributions of pyrolytic only near industrialized and urban areas. A high contribution of perylene, a geochemically derived PAH, to the total PAHs was found in the west and south at sites influenced by the Kura, Safid Rud, Terek, Sulak and Samur Rivers. PMID:14725875

Tolosa, Imma; de Mora, Stephen; Sheikholeslami, Mohammad Reza; Villeneuve, Jean Pierre; Bartocci, Jean; Cattini, Chantal

2004-01-01

27

Saturated and aromatic mineral oil hydrocarbons from paperboard food packaging: estimation of long-term migration from contents in the paperboard and data on boxes from the market.  

PubMed

In the absence of a functional barrier, mineral oil hydrocarbons from printing inks and recycled fibres tend to migrate from paper-based food-packaging materials through the gas phase into dry food. Concentrations easily far exceed the limit derived from the acceptable daily intake (ADI) of the Joint FAO/WHO Expert Committee on Food Additives (JECFA). Since the estimation of long-term migration into the food by testing at 40°C for 10 days is difficult, it seems preferable (and easier) to use the mineral oil content in the paperboard. Evaporation experiments showed that hydrocarbons eluted up to about n-C?? are sufficiently volatile for relevant migration into dry food: in worst-case situations, about 80% migrate into the packed food. The extraction of the paperboard was optimised to give good recovery of the relevant hydrocarbons, but to discriminate against those of high molecular mass which tend to disturb gas chromatographic analysis in on-line coupled normal phase HPLC-GC-FID. Even though some of the relevant hydrocarbons had already evaporated, the average concentration of < C?? mineral oil saturated hydrocarbons (MOSH) in the paperboard boxes of 102 products from the Swiss and Italian market was 626 mg kg?¹. Nearly 15% of investigated boxes still contained more than 1000 mg kg?¹ < C?? MOSH up to over 3000 mg kg?¹ (maximum = 3500 mg kg?¹). This amount of MOSH in the board have the potential of contaminating the packed food at a level exceeding the limit, derived from the JECFA ADI, hundreds of times. PMID:20967663

Lorenzini, R; Fiselier, K; Biedermann, M; Barbanera, M; Braschi, I; Grob, K

2010-12-01

28

POLYCYCLIC AROMATIC HYDROCARBON (PAH) EXPOSURE OF 257 PRESCHOOL CHILDREN  

EPA Science Inventory

We investigated the polycyclic aromatic hydrocarbon (PAH) exposure of 257 preschool children and their adult caregivers in their everyday environments. Participants were recruited randomly from eligible homes and daycare centers within six North Carolina (NC) and six Ohio (OH) c...

29

DETERMINATION OF POLYNUCLEAR AROMATIC HYDROCARBONS IN INDUSTRIAL AND MUNICIPAL WASTEWATERS  

EPA Science Inventory

A method for the determination of 16 polynuclear aromatic hydrocarbons (PAH) in wastewater was developed. This method, based on the use of high performance liquid chromatography with ultraviolet and fluorescence detection, is readily suited for detection of condensed ring aromati...

30

Modeling the biodegradability and physicochemical properties of polycyclic aromatic hydrocarbons  

E-print Network

The biodegradability and physicochemical properties of unsubstituted and methylated polycyclic aromatic hydrocarbons (PAHs) were investigated. The focus was on the development of models expressing the influence of molecular structure and properties...

Dimitriou-Christidis, Petros

2006-10-30

31

POLYNUCLEAR AROMATIC HYDROCARBONS IN ESTUARINE AND NEARSHORE ENVIRONMENTS  

EPA Science Inventory

Polynuclear aromatic hydrocarbons (PNAH) are ubiquitous and are found in waters, soil, and bottom sediments throughout the world, although the concentrations are higher in industrialized locations. Interest in these compounds is generated by their carcinogenic and mutagenic prope...

32

CONSTRUCTING MICROBIAL STRAINS FOR DEGRADATION OF HALOGENATED AROMATIC HYDROCARBONS  

EPA Science Inventory

The book chapter examines methods that have been used to isolate and to construct bacteria capable of growing aerobically with chlorinated aromatic compounds, including chlorinated hydrocarbons. It also describes some recent work in this area of research....

33

ADSORPTION OF POLYCYCLIC AROMATIC HYDROCARBONS IN AGED HARBOR SEDIMENTS  

EPA Science Inventory

Polycyclic aromatic hydrocarbons (PAHs) are a group of hydrophobic organic contaminants which have low aqueous solubilities and are common pollutants in harbor sediments. Adsorption and desorption isotherms for PAHs are conducted to study the abiotic sorption of PAHs in uncontami...

34

Study of the Adsorption of Aromatic Hydrocarbons by Marine Sediments.  

National Technical Information Service (NTIS)

Three aromatic hydrocarbons--benzene, naphthalene, and phenanthrene--were rapidly and strongly adsorbed by intertidal sediments from Jakolof Bay, lower Cook Inlet. Adsorption of phenanthrene was more than twice that of naphthalene and benzene. Adsorption ...

S. M. Henrichs, M. Luoma, S. Smith

1997-01-01

35

Photoacoustic spectroscopic studies of polycyclic aromatic hydrocarbons  

NASA Astrophysics Data System (ADS)

Because of their involvement in environmental pollutants, in carcinogenic activity, plastics, pharmaceuticals, synthesis of some laser dyes and presence in interstellar space etc., Polycyclic aromatic hydrocarbons (PAHs) are important. As their structure and properties can be varied systematically, they form a beautiful class of molecules for experimental and quantum chemical investigations. These molecules are being studied for last several years by using conventional spectroscopy. In recent years, Photoacoustic (PA) spectroscopy has emerged as a new non-destructive technique with unique capability and sensitivity. The PA effect is the process of generation of acoustic waves in a sample resulting from the absorption of photons. This technique not only reveals non- radiative transitions but also provides information about forbidden singlet-triplet transitions which are not observed normally by the conventional spectroscopy. The present paper deals with the spectroscopic studies of some PAH molecules by PA spectroscopy in the region 250 - 400 nm. The CNDO/S-CI method is used to calculate the electronic transitions with the optimized geometries. A good agreement is found between the experimental and calculated results.

Zaidi, Zahid H.; Kumar, Pardeep; Garg, R. K.

1999-02-01

36

Polynuclear aromatic hydrocarbons in the water environment*  

PubMed Central

Many polynuclear aromatic hydrocarbons (PAH) are known to be carcinogenic to animals and probably to man. This review is concerned with carcinogenic and non-carcinogenic PAH in the water environment, with emphasis on 3,4-benzpyrene (BP) because it is ubiquitous, is one of the most potent of the carcinogenic PAH and has been widely studied. Although PAH are formed in combustion and other high-temperature processes, there is also evidence for their endogenous formation in plants, which may explain their ubiquity therein. Although the solubility of these compounds in pure water is very low, they may be solubilized by such materials as detergents, or they may otherwise occur in aqueous solution associated with or adsorbed on to a variety of colloidal materials or biota, and thereby be transported through the water environment. A notable characteristic of PAH is their sensitivity to light. PAH have been found in industrial and municipal waste effluents, and occur in soils, ground waters and surface waters, and their sediments and biota. With the exception of filtration or sorption by activated carbon, conventional water treatment processes do not efficiently remove them, and they have been found in domestic water supplies. Because of the ubiquity of PAH in the environment, it is impossible to prevent completely man's exposure to them; nevertheless their surveillance should be continued and their concentrations in the environment should be reduced where practicable. PMID:4100719

Andelman, Julian B.; Suess, Michael J.

1970-01-01

37

Ultrasonic degradation of polycyclic aromatic hydrocarbons  

SciTech Connect

Trace amounts of the polycyclic aromatic hydrocarbons (PAHs) present in the environment are of concern due to their hazardous nature. Conventional processes for degrading PAH are time consuming and inefficient, and they require costly equipment; furthermore, they contribute to other problems. Ultrasound can provide the highly energetic hydrogen atom and hydroxyl radicals, whose reactivity accounts for the destruction of organic solutes, in a very short time. The degradation mechanisms and the degradation efficiency for 1-methylnaphthalene, anthracene, phenanthrene, pyrene, 1,12-benzoperylene, and coronene, in dilute organic solvent-water solutions, were studied under ultrasound on a laboratory scale. The extent of degradation is followed by ultraviolet (UV)-visible spectrometry. The effects of additional agents, such as hydrogen peroxide, sodium borohydride, and dissolved gas, were investigated. The catalytic effects of ferrous chloride and nickel chloride were investigated. A total of 70 to 83% of PAH was degraded as a result of the additional agents and 2 hours of ultrasound. The higher percentage of degradation was caused by the greater abundance of free radicals, especially hydroxyl, for cleavage. However, with the catalysts, the added PAH degradation efficiency was not significant.

Park, J.K.; Yen, T.F. [Univ. of Southern California, Los Angeles, CA (United States). Dept. of Civil and Environmental Engineering

1995-12-31

38

Double photoionization of pyrene and other aromatic hydrocarbons  

NASA Astrophysics Data System (ADS)

We have measured the ratio of doubly to singly charged parent ions of pyrene, an aromatic hydrocarbon, for photon energies ranging from threshold to the carbon K edge. Monochromatized synchrotron radiation of the Synchrotron Radiation Center has been used in combination with an ion time-of-flight spectrometer for this investigation. We compared these results with our previous measurements on benzene, coronene and pyrrole. We will discuss differences and similarities in the double photoionization for these aromatic hydrocarbons.

Wehlitz, R.; Hartman, T.

2014-04-01

39

Aliphatic and aromatic hydrocarbons in coastal caspian Sea sediments  

Microsoft Academic Search

This investigation represents the first extensive study of the spatial distribution and sources of aliphatic (n-alkanes and unresolved complex mixture of fossil hydrocarbons) and polycyclic aromatic hydrocarbons (PAHs) in coastal sediments from the Caspian Sea. PAH concentrations, n-alkanes and biomarker profiles all suggested that there was limited petrogenic contamination in the shallow North Caspian Sea sediments, which are coarse with

Imma Tolosa; Stephen de Mora; Mohammad Reza Sheikholeslami; Jean-Pierre Villeneuve; Jean Bartocci; Chantal Cattini

2004-01-01

40

Distributions of polycyclic aromatic hydrocarbons and alkylated polycyclic aromatic hydrocarbons in Osaka Bay, Japan.  

PubMed

Contaminations in sediments by polycyclic aromatic hydrocarbons (PAHs) and alkylated PAHs were investigated at 44 sites in Osaka Bay, Japan. Concentrations of total PAHs and alkylated PAHs were in the range 6.40-7800 ng/g dry weights and 13.7-1700 ng/g dry weights, respectively. The PAH concentrations tended to be higher along the shoreline in the vicinities of big ports, industrialized areas, and densely populated regions such as the cities of Osaka and Kobe. The major sources appeared to be pyrogenic or both pyrogenic and petrogenic at most of the sites. PAH concentrations were remarkably high at a site near Kobe, where the concentrations of dibenzo(a,h)anthracene and benzo(g,h,i)perylene exceeded the effects-range-medium concentration and eight PAHs were above the corresponding effects-range-low concentrations. Those PAHs may have been derived from the great fire associated with the large earthquake in 1995. PMID:24775067

Miki, Shizuho; Uno, Seiichi; Ito, Kazuki; Koyama, Jiro; Tanaka, Hiroyuki

2014-08-30

41

Manufacture of aromatic hydrocarbons from coal hydrogenation products  

SciTech Connect

The manufacture of aromatic hydrocarbons from coal distillates was experimentally studied. A flow chart for the production of benzene, ethylbenzene, toluene, and xylenes was designed, which comprised the hydrogen treatment of the total wide-cut (or preliminarily dephenolized) fraction with FBP 425{sup o}C; fractional distillation of the hydrotreated products into IBP-60, 60-180, 180-300, and 300-425{sup o}C fractions; the hydro-cracking of middle fractions for increasing the yield of gasoline fractions whenever necessary; the catalytic reform of the fractions with bp up to 180{sup o}C; and the extraction of aromatic hydrocarbons.

A.S. Maloletnev; M.A. Gyul'malieva [Institute for Fossil Fuels, Moscow (Russian Federation)

2007-08-15

42

Determination of low concentrations of aromatic hydrocarbons in multicomponent mixtures with iso-octane and n-heptane  

NASA Astrophysics Data System (ADS)

We have experimentally studied the absorption spectra of hydrocarbon mixtures based on n-heptane and isooctane with small (1%-2%) additions of aromatic hydrocarbons (benzene, toluene, xylene). The study was conducted in the region of the first overtones of the vibrational spectra for the hydrocarbon groups CH3, CH2, CH. We show that four-component modeling of the absorption spectrum of the hydrocarbon mixture and minimization of the deviation of the model spectrum from the experimental spectrum allow us to separately determine the content of the aromatic additives for concentrations from 1%.

Vesnin, V. L.; Muradov, V. G.

2011-11-01

43

Aromaticity of Polycyclic Conjugated Hydrocarbons Milan Randic*  

E-print Network

Heisenberg). Supek introduced him to the book by Linus Pauling, The Nature of the Chemical Bond for Benzenoid Hydrocarbons 3490 1. Pauling-Wheland Valence Bond Approach 3490 2. Pauling-Wheland Resonance

Ferreira, Márcia M. C.

44

40 CFR Table 2c to Subpart E of... - Reactivity Factors for Aromatic Hydrocarbon Solvent Mixtures  

Code of Federal Regulations, 2010 CFR

...false Reactivity Factors for Aromatic Hydrocarbon Solvent Mixtures 2C Table 2C to Subpart E of Part 59 Protection of Environment...Part 59—Reactivity Factors for Aromatic Hydrocarbon Solvent Mixtures Bin Boiling range (degrees F) Criteria...

2010-07-01

45

40 CFR Table 2c to Subpart E of... - Reactivity Factors for Aromatic Hydrocarbon Solvent Mixtures  

Code of Federal Regulations, 2013 CFR

...false Reactivity Factors for Aromatic Hydrocarbon Solvent Mixtures 2C Table 2C to Subpart E of Part 59 Protection of Environment...Part 59—Reactivity Factors for Aromatic Hydrocarbon Solvent Mixtures Bin Boiling range(degrees F) Criteria...

2013-07-01

46

40 CFR Table 2c to Subpart E of... - Reactivity Factors for Aromatic Hydrocarbon Solvent Mixtures  

Code of Federal Regulations, 2012 CFR

...false Reactivity Factors for Aromatic Hydrocarbon Solvent Mixtures 2C Table 2C to Subpart E of Part 59 Protection of Environment...Part 59—Reactivity Factors for Aromatic Hydrocarbon Solvent Mixtures Bin Boiling range(degrees F) Criteria...

2012-07-01

47

40 CFR Table 2c to Subpart E of... - Reactivity Factors for Aromatic Hydrocarbon Solvent Mixtures  

Code of Federal Regulations, 2011 CFR

...false Reactivity Factors for Aromatic Hydrocarbon Solvent Mixtures 2C Table 2C to Subpart E of Part 59 Protection of Environment...Part 59—Reactivity Factors for Aromatic Hydrocarbon Solvent Mixtures Bin Boiling range (degrees F) Criteria...

2011-07-01

48

Experimental and modeling investigation of aromatic and polycyclic aromatic hydrocarbon formation in a premixed ethylene flame  

SciTech Connect

Experimental and detailed chemical kinetic modeling has been performed to investigate aromatic and polyaromatic hydrocarbon formation pathways in a rich, sooting, ethylene-oxygen-argon premixed flame. An atmospheric pressure, laminar flat flame operated at an equivalence ratio of 2.5 was used to acquire experimental data for model validation. Gas composition analysis was conducted by an on-line gas chromatograph/mass spectrometer (GC/MS) technique. Measurements were made in the flame and post-flame zone for a number of low molecular weight species, aliphatics, aromatics and polycyclic aromatic hydrocarbons (PAHs) ranging from two to five-aromatic fused rings. The modeling results show the key reaction sequences leading to aromatic and polycyclic aromatic hydrocarbon growth involve the combination of resonantly stabilized radicals. In particular, propargyl and 1-methylallenyl combination reactions lead to benzene and methyl substituted benzene formation, while polycyclic aromatics are formed from cyclopentadienyl radicals and fused rings that have a shared C{sub 5} side structure. Naphthalene production through the reaction step of cyclopentadienyl self-combination and phenanthrene formation from indenyl and cyclopentadienyl combination were shown to be important in the flame modeling study. The removal of phenyl by O{sub 2} leading to cyclopentadienyl formation is expected to play a pivotal role in the PAH or soot precursor growth process under fuel-rich oxidation conditions.

Castaldi, M.J.; Marinov, N.M.; Melius, C.F. [and others

1996-02-01

49

Polycyclic aromatic hydrocarbons and mutagens in ambient air particles  

Microsoft Academic Search

The presence of mutagenic compounds in ambient air particles has led to a reassessment of the role of polycyclic aromatic hydrocarbons (PAH) in air pollution research. Besides PAH, other air pollutants were associated with carcinogenicity, although by means of an effect which indirectly and preliminarily indicates carcinogenicity. While PAH themselves are mutagens, they only marginally contribute to the mutagenicity of

W. K. de Raat

1988-01-01

50

Sources of polycyclic aromatic hydrocarbons to the Hudson River Airshed  

Microsoft Academic Search

Sources of polycyclic aromatic hydrocarbons (PAHs) to the Hudson River Estuary Airshed were investigated using positive matrix factorization (PMF). A three-city dataset was used to obtain common factor profiles. The contributions of each factor on each sampling day and site were then determined, and a sensitivity analysis was conducted. A stable eight-factor solution was identified. PMF was able to identify

Jong Hoon Lee; Cari L. Gigliotti; John H. Offenberg; Steven J. Eisenreich; Barbara J. Turpin

2004-01-01

51

CHILDREN'S AGGREGATE EXPOSURE TO POLYCYCLIC AROMATIC HYDROCARBONS (PAHS)  

EPA Science Inventory

Polycyclic aromatic hydrocarbons (PAHs) have been frequently detected at children's homes and day care centers and may pose health concerns due to their carcinogenicity. Most PAHs have been persistent indoors and outdoors, therefore, children may be exposed to chronic low level...

52

Sorption of polycyclic aromatic hydrocarbons (PAHs) on glass surfaces  

Microsoft Academic Search

Sorption of polycyclic aromatic hydrocarbons (PAHs) to glass commonly used in laboratories was studied. Sorption coefficients (Kd) of five selected PAHs to borosilicate glass surfaces were measured using column chromatography. A linear relationship between log Kd and the corresponding water solubility of the subcooled liquid (logSw) of the investigated PAHs was observed. Based on the determined sorption coefficients our data

Yuan Qian; Tjorben Posch; Torsten C. Schmidt

2011-01-01

53

ENVIRONMENTAL CARCINOGENIC POLYCYCLIC AROMATIC HYDROCARBONS: PHOTOCHEMISTRY AND PHOTOTOXICITY  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs) are a class of environmental contaminants that has long been of interest in the fields of organic chemistry, theoretical chemistry, physical chemistry, environmental science, toxicology, cancer research, and energy sciences. Concerning environmental science and cancer research, majority of the research has focused on the occurrence, environmental fate, degradation\\/remediation, chemical transformation, genotoxicity, metabolism and metabolic activation, DNA

Hongtao Yu

2002-01-01

54

Formation mechanism for polycyclic aromatic hydrocarbons in methane flames  

E-print Network

of the flame. The yellow color shows the presence of soot particles in the flame as they radiate due to PlanckFormation mechanism for polycyclic aromatic hydrocarbons in methane flames K. Siegmanna) Swiss 96822 Received 24 August 1999; accepted 13 October 1999 A laminar diffusion flame of methane

Sattler, Klaus

55

Biodegradation aspects of Polycyclic Aromatic Hydrocarbons (PAHs): A review  

Microsoft Academic Search

PAHs are aromatic hydrocarbons with two or more fused benzene rings with natural as well as anthropogenic sources. They are widely distributed environmental contaminants that have detrimental biological effects, toxicity, mutagenecity and carcinogenicity. Due to their ubiquitous occurrence, recalcitrance, bioaccumulation potential and carcinogenic activity, the PAHs have gathered significant environmental concern. Although PAH may undergo adsorption, volatilization, photolysis, and chemical

A. K. Haritash; C. P. Kaushik

2009-01-01

56

Polycyclic Aromatic Hydrocarbon Degrading Microorganisms in Great Lakes Sediments  

Microsoft Academic Search

Biodegradation is a chemical transformation process that may result in the decontamination of sediments. A criterion for the potential success of biode gradation is the ability of indigenous microorganisms to catabolize contaminants, such as polycyclic aromatic hydrocarbons (PAHs). The number of microorganisms displaying this ability may be influenced by the extent of their exposure to PAHs. In this study, microorganisms

Dan L. McNally; James R. Mihelcic; Donald R. Lueking

1998-01-01

57

COHERENT ANTI-STOKES RAMAN SPECTROSCOPY OF POLYCYCLIC AROMATIC HYDROCARBONS  

EPA Science Inventory

Coherent anti-Stokes Raman spectroscopy (CARS) was used to obtain Raman spectra of thirteen polycyclic aromatic hydrocarbons (PAHs) composed of between three and seven fused rings. The compounds were pumped in the resonance and preresonance regions to obtain the sensitivity neces...

58

Microbial Degradation of Polycyclic Aromatic Hydrocarbons and Characterization of Bacteria  

NASA Astrophysics Data System (ADS)

Biodegradation of polycyclic aromatic hydrocarbons was studied. Naphthalene was used as a model compound to represent these compounds. Low initial concentrations of naphthalene in a range of 30-60 mg/L were completely degraded after incubation for 15 hrs by consortia from a landfill soil while consortia from minewater took more that 29 hrs to reach complete degradation.

Tikilili, P. V.; Chirwa, E. M. N.

2010-01-01

59

Biodegradation of aromatic hydrocarbons by aquifer microorganisms under denitrifying conditions  

Microsoft Academic Search

A series of laboratory tests were conducted to evaluate whether denitrification would be a suitable alternative for biorestoration of an aquifer contaminated with JP-4 jet fuel. Microcosms were prepared from both uncontaminated and contaminated aquifer material from the site, in an anaerobic glovebox, amended with nitrate, nutrients, and aromatic hydrocarbons, and incubated under a nitrogen atmosphere at 12C. With uncontaminated

Stephen R. Hutchins; Guy W. Sewell; David A. Kovacs

1991-01-01

60

THE RATES OF POLYCYCLIC AROMATIC HYDROCARBON EMISSIONS FROM INCENSE BURNING  

EPA Science Inventory

The paper presents the results of experiments performed to determine the amounts of gas- and particle-phase polycyclic aromatic hydrocarbons (PAHS) in incense smoke. Ten brands of incense, 3 of stick, 2 of joss stick, and one each of cone, smudge bundle, rope, powder, and rock, w...

61

Consensus sediment quality guidelines for polycyclic aromatic hydrocarbon mixtures  

Microsoft Academic Search

Sediment quality guidelines (SQGs) for polycyclic aromatic hydrocarbons (PAHs) have been derived from a variety of laboratory, field, and theoretical foundations. They include the screening level concentration, effects ranges-low and -median, equilibrium partitioning concentrations, apparent effects threshold, ΣPAH model, and threshold and probable effects levels. The resolution of controversial differences among the PAH SQGs lies in an understanding of the

Richard C. Swartz

1999-01-01

62

Hot-melt adhesive properties of EVA\\/aromatic hydrocarbon resin blend  

Microsoft Academic Search

A series of ethylene vinyl acetate copolymers (EVAs) were blended with aromatic hydrocarbon resins for use as hot-melt adhesives. The glass transition temperature, viscoelastic properties, melt viscosity, crystallinity and adhesion properties of the EVA\\/aromatic hydrocarbon resin system were determined as a function of the softening point of the aromatic hydrocarbon resin, the blend ratio of the two components and the

Young-Jun Park; Hyun-Joong Kim

2003-01-01

63

Black carbon and polycyclic aromatic hydrocarbons (PAHs) in surface sediments of China’s marginal seas  

Microsoft Academic Search

This study investigates the distribution of black carbon (BC) and its correlation with total polycyclic aromatic hydrocarbons\\u000a (?PAH) in the surface sediments of China’s marginal seas. BC content ranges from <0.10 to 2.45 mg\\/g dw (grams dry weight)\\u000a in the sediments studied, and varied among the different coastal regions. The Bohai Bay sediments had the highest BC contents\\u000a (average 2.18

Yanju Kang; Xuchen Wang; Minhan Dai; Huan Feng; Anchun Li; Qian Song

2009-01-01

64

Accumulation and release of petroleum-derived aromatic hydrocarbons by four species of marine animals  

Microsoft Academic Search

When exposed to oil-contaminated seawater, marine animals accumulate a wide variety of petroleum hydrocarbons in their tissues. Generally, the aromatic hydrocarbons are accumulated to a greater extent and are retained longer than the alkanes. In all species tested, accumulation of aromatic hydrocarbons appears to be dependent primarily on a partitioning of the hydrocarbons between the exposure water and the tissue

J. M. Neff; B. A. Cox; D. Dixit; J. W. Anderson

1976-01-01

65

Mutagenicity (micronucleus test in Vicia faba root tips), polycyclic aromatic hydrocarbons and heavy metal content of sediments collected in Tiber river and its tributaries within the urban area of Rome.  

PubMed

Sediments collected in Tiber river and in its main tributary water courses within the urban area of Rome were tested for mutagenicity by means of Vicia faba root tips micronucleus (MN) test. Representative samples were scored for micronucleus generating events (chromosome/chromatid loss and fragments) too. Sediments were assayed for content of the thirteen most important chemicals of polycyclic aromatic hydrocarbon (PAH) group and for some heavy metal ions (Cd, Cr, Cu, Ni, Pb, Zn). Samples were collected in four tributary rivers (Prima Porta, Acqua Traversa, Aniene and Magliana) just before their confluence with Tiber river and at different stations along the Tiber river itself upstream and downstream the sites of confluence of the sampled tributaries. All samples were collected in July 1992. An alarming level of mutagenicity was reached in most of the tested stations, with an effect comparable to an X-rays exposure up to 0.4 Gy. Chemical analysis showed that the total amount of identified PAHs ranged from 4.5 to 625.2 ng/g of dry matrix in the different stations and the total amount of heavy metals ranged from 130 to 570 ppm. Tiber mutagenicity is likely to be mainly due to local factors such as the confluence of a small polluted tributary rather than to large scale effect due to an upstream-downstream relationship. PMID:9838054

Minissi, S; Caccese, D; Passafiume, F; Grella, A; Eleonora, C; Rizzoni, M

1998-12-01

66

Occupational exposure to Polycyclic Aromatic Hydrocarbons in wood dust  

NASA Astrophysics Data System (ADS)

Sino-nasal cancer (SNC) represents approximately 3% of Oto-Rhino-Laryngology (ORL) cancers. Adenocarcinoma SNC is an acknowledged occupational disease affecting certain specialized workers such as joiners and cabinetmakers. The high proportion of woodworkers contracting a SNC, subjected to an estimated risk 50 to 100 times higher than that affecting the general population, has suggested various study paths to possible causes such as tannin in hardwood, formaldehyde in plywood and benzo(a)pyrene produced by wood when overheated by cutting tools. It is acknowledged that tannin does not cause cancer to workers exposed to tea dust. Apart from being an irritant, formaldehyde is also classified as carcinogenic. The path involving carcinogenic Polycyclic Aromatic Hydrocarbons (PAHs) emitted by overheated wood is attractive. In this study, we measured the particle size and PAHs content in dust emitted by the processing of wood in an experimental chamber, and in field situation. Quantification of 16 PAHs is carried out by capillary GC-ion trap Mass Spectrometric analysis (GC-MS). The materials tested are rough fir tree, oak, impregnated polyurethane (PU) oak. The wood dust contains carcinogenic PAHs at the level of ?g.g-1 or ppm. During sanding operations, the PU varnish-impregnated wood produces 100 times more PAHs in dust than the unfinished wood.

Huynh, C. K.; Schüpfer, P.; Boiteux, P.

2009-02-01

67

Polycyclic aromatic hydrocarbon biodegradation by a mixed bacterial culture  

SciTech Connect

Biodegradation of polycyclic aromatic hydrocarbons (PAHs), which are a complex mixture of organic compounds, was demonstrated using a bacterial mixed culture selected from a contaminated site by the BIOPRACT GmbH. The investigations were carried out in a laboratory fermenter using emulsified tar oil as the substrate to determine the following: (1) concentration of the single PAH and of the sum of PAHs relative to fermentation time, (2) carbon dioxide (CO{sub 2}) and oxygen (O{sub 2}) content in the outflowing air during fermentation, (3) chemical oxygen demand (COD) of the broth, and (4) toxicity of the broth before and after fermentation according to the bioluminescence test (DIN 38412, part 34/1). The results of this model experiment indicated that the investigated mixed culture is able to effectively metabolize the PAHs contained in tar oil, including the higher condensed compounds such as benzo(a)pyrene. In the first 8 days of fermentation, the PAH sum decreased to below 5% of the starting concentration connected with a five-fold reduction of the toxic effect on Vibrio fischeri. The PAH degradation rate correlated with the rate of COD decrease, the rate of evolving CO{sub 2}, and the consumption of O{sub 2}.

Dreyer, G.; Koenig, J.; Ringpfeil, M. [BIOPRACT GmbH, Berlin (Germany)

1995-12-31

68

Phototransformation of polycyclic aromatic hydrocarbons into stable, mutagenic components  

SciTech Connect

This report compares the mutagenicity of photochemical products produced by exposure of the polycyclic aromatic hydrocarbons benzo(a)pyrene and 9,10-dimethylanthracene or the aromatic amines 2-aminofluorene, 2-aminoanthracene and 2-aminonaphthalene to sunlight or to ultraviolet light (UVA). 2-Aminofluorene, giving the most active products, was further investigated with respect to the mechanism of photoactivation and the chemical identity of the photochemical products. Screening of HPLC resolved photochemical products demonstrated that the majority of the mutagenicity was localized to one peak - which co-chromatographed with 2-nitrofluorene.

Okinaka, R.T.; Nickols, J.W.; Whaley, T.W.; Strniste, G.F.

1983-01-01

69

Sequential extraction of polycyclic aromatic hydrocarbons using subcritical water  

Microsoft Academic Search

A rapid sequential subcritical (superheated) water extraction method for polycyclic aromatic hydrocarbons (PAHs) in contaminated soil and sediment is presented. Decreasing the polarity of water by successive increase of the extraction temperature from 50°C to 200°C at the moderate pressure (10.3MPa) enabled selective, non-exhaustive extractions to be performed. Concurrent with increasing temperatures to 150°C there was an increase in PAH

Agnieszka E. Latawiec; Brian J. Reid

2010-01-01

70

Oxidation of Polycyclic Aromatic Hydrocarbons under Sulfate-Reducing Conditions  

PubMed Central

[(sup14)C]naphthalene and phenanthrene were oxidized to (sup14)CO(inf2) without a detectable lag under strict anaerobic conditions in sediments from San Diego Bay, San Diego, Calif., that were heavily contaminated with polycyclic aromatic hydrocarbons (PAHs) but not in less contaminated sediments. Sulfate reduction was necessary for PAH oxidation. These results suggest that the self-purification capacity of PAH-contaminated sulfate-reducing environments may be greater than previously recognized. PMID:16535261

Coates, J. D.; Anderson, R. T.; Lovley, D. R.

1996-01-01

71

Photolysis of polycyclic aromatic hydrocarbons adsorbed on simulated atmospheric particulates  

Microsoft Academic Search

Fifteen polycyclic aromatic hydrocarbons (PAH) adsorbed on silica gel, alumina, fly ash, and carbon black were photolyzed in order to study their atmospheric fate. Photolytic half-lives for these particle-bound PAH were found to be highly dependent on the substrate to which they were adsorbed. On silica gel and alumina, PAH showed a wide range of photolytic half-lives, indicating a relationship

Thomas D. Behymer; Ronald A. Hites

1985-01-01

72

Polycyclic Aromatic Hydrocarbons Residues in Sandstorm Depositions in Beijing, China  

Microsoft Academic Search

This study was conducted to determine the concentration of 16 polycyclic aromatic hydrocarbons (PAHs) in sandstorm depositions\\u000a in Beijing, China. The PAH concentrations in 13 samples collected in Beijing ranged from 0.18 to 3.52 ?g g?1. Analysis of the sources of contamination revealed that the PAHs were derived from a coal combustion source, although various\\u000a effects of traffic emissions were also observed.

S. Fu; K. Li; X. J. Xia; X. B. Xu

2009-01-01

73

THE INFRARED SPECTROSCOPY OF NEUTRAL POLYCYCLIC AROMATIC HYDROCARBON CLUSTERS  

SciTech Connect

The mid-infrared spectra of neutral homogeneous polycyclic aromatic hydrocarbon (PAH) clusters have been computed using density functional theory including an empirical correction for dispersion. The C-H out-of-plane bending modes are redshifted for all the clusters considered in this work. The magnitude of the redshift and the peak broadening are dependent on PAH size, shape, and on the PAH arrangement in the cluster.

Ricca, Alessandra [Carl Sagan Center, SETI Institute, 189 Bernardo Avenue, Suite 100, Mountain View, CA 94043 (United States); Bauschlicher, Charles W. Jr. [Entry Systems and Technology Division, Mail Stop 230-3, NASA Ames Research Center, Moffett Field, CA 94035 (United States); Allamandola, Louis J., E-mail: Alessandra.Ricca-1@nasa.gov, E-mail: Charles.W.Bauschlicher@nasa.gov [Space Science Division, Mail Stop 245-6, NASA Ames Research Center, Moffett Field, CA 94035 (United States)

2013-10-10

74

Polycyclic Aromatic Hydrocarbon (PAH) Degradation Coupled to Methanogenesis  

Microsoft Academic Search

Baltimore Harbor (Baltimore, MD) sediments were utilized to initiate anaerobic enrichment cultures with polycyclic aromatic\\u000a hydrocarbons (PAHs) in the absence of supplementary electron acceptors. Cultures amended with naphthalene and phenanthrene\\u000a exhibited sustained, transferable degradation of the PAHs. Bromoethanesulfonic acid, a selective inhibitor of methanogenesis,\\u000a inhibited the degradation of 200 ?m naphthalene and phenanthrene; molecular characterization based on 16S rRNA sequences confirmed

Wook Chang; Youngsoon Um; Tracey R. Pulliam Holoman

2006-01-01

75

Anaerobic biodegradation of polycyclic aromatic hydrocarbon in soil  

Microsoft Academic Search

Known concentrations of phenanthrene, pyrene, anthracene, fluorene and acenapthene were added to soil samples to investigate the anaerobic degradation potential of polycyclic aromatic hydrocarbon (PAH). Consortia-treated river sediments taken from known sites of long-term pollution were added as inoculum. Mixtures of soil, consortia, and PAH (individually or combined) were amended with nutrients and batch incubated. High-to-low degradation rates for both

B. V Chang; L. C Shiung; S. Y Yuan

2002-01-01

76

Biomarkers in humans exposed to polycyclic aromatic hydrocarbons  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAH) have been identified as a major source of carcinogenic risk in the coke-oven industry. This study evaluates following markers: personal exposure to PAH, DNA adducts, chromosomal aberrations and sister chromatid exchanges (SCE), glutathione S-transferase M1 (GSTM1) and N-acetyltransferase 2 (NAT2) polymorphisms. 23 top side coke-oven workers and 13 unexposed workers employed in the same plant at

B. Binkova; J. Topinka; G. Mrackova

1997-01-01

77

Ozonation of Polycyclic Aromatic Hydrocarbons in Water Solution  

Microsoft Academic Search

The degradation of three polycyclic aromatic hydrocarbons (PAHs): benzo[a]pyrene (BAP), chrysene (CHR), and fluorene (FLU) in aqueous solution using ozone was investigated. The influence of pH of the reaction mixture, ozone concentration, and the presence of a radical scavenger on the reaction rate was determined. The highest rate of PAHs disappearance was achieved in acidic solutions. The radical scavenger, tert-butanol,

Jacek S. Miller; Dorota Olejnik

2004-01-01

78

Dermal exposure to polycyclic aromatic hydrocarbons in asphalt workers  

Microsoft Academic Search

ObjectivesTo assess dermal exposure to 16 polycyclic aromatic hydrocarbons (PAHs) in asphalt workers by applying polypropylene pads to six body sites (neck, shoulder, upper arm, wrist, groin, ankle), to identify the compounds and exposure sites most representative, and to integrate dermal exposure results with environmental and biological data.MethodsTwenty-four asphalt workers were recruited. Dermal exposure was assessed during a single work

Silvia Fustinoni; Laura Campo; Piero E Cirla; Irene Martinotti; Marina Buratti; Omar Longhi; Vito Foà; PierAlberto Bertazzi

2009-01-01

79

[Distribution of various polycyclic aromatic hydrocarbons in reservoir water of Estonia].  

PubMed

The paper presents experimental data on different polycyclic aromatic hydrocarbons (PAH) in water, bottom sediments and algae as well as evidence available in literature on their content in exhausts of automobiles, oil shale industry and power station. Attempts are made to reveal differences in sources of the environment pollution with allowance for different PAH/benzo(a)pyrene percentage ratio, but as the PAH ratios are relatively similar in different pollution sources this attempt was a failure. PMID:4006850

Veldre, I A; Itra, A R; Paal'me, L P; Urbas, E R

1985-01-01

80

Aerosol formation and growth in atmospheric aromatic hydrocarbon photooxidation  

SciTech Connect

An experimental study of aerosol formation in aromatic hydrocarbonNO/sub x/ systems has been conducted in an outdoor smog chamber. Aerosol size distributions were measured as a function of time in toluene, m-xylene, ethylbenzene, or 1,3,5-trimethylbenzene photooxidations to determine the rates of new particle formation and the effects of initial particles on aerosol formation and growth. Aerosol yields from the aromatic gas-phase photooxidations were found to be approximately 2-5% by mass of the starting aromatic species. Simulations of the aerosol behavior in these experiments have been carried out using an integral model that includes a vapor source, homogeneous nucleation, condensational growth, and particle loss by deposition. Predictions from the model are in relatively good agreement with the experimental observations. Results indicate that the nucleation mechanism in these systems is still not completely understood. 36 references, 9 figures, 1 table.

Stern, J.E.; Flagan, R.C.; Grosjean, D.; Seinfeld, J.H.

1987-12-01

81

MODELING GALACTIC EXTINCTION WITH DUST AND 'REAL' POLYCYCLIC AROMATIC HYDROCARBONS  

SciTech Connect

We investigate the remarkable apparent variety of galactic extinction curves by modeling extinction profiles with core-mantle grains and a collection of single polycyclic aromatic hydrocarbons. Our aim is to translate a synthetic description of dust into physically well-grounded building blocks through the analysis of a statistically relevant sample of different extinction curves. All different flavors of observed extinction curves, ranging from the average galactic extinction curve to virtually 'bumpless' profiles, can be described by the present model. We prove that a mixture of a relatively small number (54 species in 4 charge states each) of polycyclic aromatic hydrocarbons can reproduce the features of the extinction curve in the ultraviolet, dismissing an old objection to the contribution of polycyclic aromatic hydrocarbons to the interstellar extinction curve. Despite the large number of free parameters (at most the 54 Multiplication-Sign 4 column densities of each species in each ionization state included in the molecular ensemble plus the 9 parameters defining the physical properties of classical particles), we can strongly constrain some physically relevant properties such as the total number of C atoms in all species and the mean charge of the mixture. Such properties are found to be largely independent of the adopted dust model whose variation provides effects that are orthogonal to those brought about by the molecular component. Finally, the fitting procedure, together with some physical sense, suggests (but does not require) the presence of an additional component of chemically different very small carbonaceous grains.

Mulas, Giacomo; Casu, Silvia; Cecchi-Pestellini, Cesare [INAF-Osservatorio Astronomico di Cagliari, Strada n.54, Loc. Poggio dei Pini, I-09012 Capoterra (Italy); Zonca, Alberto, E-mail: gmulas@oa-cagliari.inaf.it, E-mail: silvia@oa-cagliari.inaf.it, E-mail: ccp@oa-cagliari.inaf.it, E-mail: azonca@oa-cagliari.inaf.it [Dipartimento di Fisica, Universita di Cagliari, Strada Prov.le Monserrato-Sestu Km 0.700, I-09042 Monserrato (Italy)

2013-07-01

82

Photolysis of polycyclic aromatic hydrocarbons adsorbed on fly ash  

SciTech Connect

Polycyclic aromatic hydrocarbons (PAH) are formed by the combustion of almost any fuel under oxygen-deficient conditions. Previous laboratory studies have found that many PAH degrade with lifetimes as short as a few hours; however, studies of marine and lacustrine sediments, the ultimate sinks of PAH, have shown relative abundances of PAH which are similar to those in combustion sources; this suggests that PAH are stable in the atmosphere. Eighteen PAH adsorbed on carbon black and fifteen coal fly ashes of varying physical and chemical composition were photolyzed in order to study their atmospheric fate. Photolytic half-lives for these particle-bound PAH were found to be highly dependent on the substrate onto which they were adsorbed. On low-carbon fly ash, PAH showed a wide range of half-lives, indicating a relationship between PAH structure and photochemical reactivity. However, PAH on carbon black and fly ashes with a high-carbon content, show similar half-lives for most PAH including reactive PAH such as anthracene and benzo(a)pyrene. This indicates a photolytic process that is independent of structure and dependent on the physical and chemical nature of the fly ash. Surprisingly, no other parameter accounts for observed PAH reactivity. Substrate characteristics such as surface area, porosity, particle size, surface pH, and iron content have all been suggested to influence the rate of PAH degradation. However, these parameters, measured for substrates studied in this thesis, do not correlate with PAH reactivity. Because carbon black and high-carbon fly ashes stabilize reactive PAH, it is these substrates which would facilitate the transport of PAH from combustion sources through the atmosphere to ultimate sinks.

Behymer, T.D.

1987-01-01

83

The distribution of aromatic hydrocarbons in western Lake Erie  

SciTech Connect

In order to determine whether biota in western Lake Erie are exposed to elevated concentrations of aromatic hydrocarbons, the authors collected biota along a corridor extending from Peche Island in the Detroit River to Pelee Island in western Lake Erie and determined concentrations of polynuclear aromatic hydrocarbons (PAHs) in zebra mussels, and levels of fluorescent aromatic compounds (FACs) in the bile of freshwater drum and gizzard shad. In addition, they deployed semi-permeable membrane devices (SPMDs) at various locations along this corridor to monitor for PAHs in water. PAHs were elevated in SPMDs and zebra mussels from the Detroit River, and PAH concentrations declined from west to east in Lake Erie. There were elevated levels of bile FACs in drum and gizzard shad from highly contaminated regions of the Detroit River. These data are consistent with the Detroit River being a significant source of PAH contamination in western Lake Erie. Since the ratios of concentrations of PAHs and PCBs in zebra mussels did not vary throughout the study area, it appears that both classes of aromatic contaminants are distributed by similar mechanisms throughout western Lake Erie.

Metcalfe, C.D.; Metcalfe, T.L.; Koenig, B.G. [Trent Univ., Peterborough, Ontario (Canada). Environmental and Resource Studies Program; Haffner, G.D. [Univ. of Windsor, Ontario (Canada). Great Lakes Inst.

1995-12-31

84

Fog processing of polycyclic aromatic hydrocarbons (PAH)  

NASA Astrophysics Data System (ADS)

Polyaromatic hydrocarbons (PAHs) are a class of organic species of concern for environmental and human health. The present work will present initial finding of a comprehensive study on the fate of PAHs in multiphase fog/cloud systems and across consecutive fog/smog cycles. Field observations were conducted in Fresno, CA in Winter 2010. Simultaneous measurements of gas phase, aerosol and fog PAH allowed to gain insights on the partitioning of PAH in a multiphase fog system. Partitioning results as well as temporal evolution of PAH concentrations across different phases will be discussed. Select known degradation products (oxy-PAH) from the processing of PAHs were also analyzed in the fog systems, although frequently their concentrations were close to or below detection limits, even in the polluted urban study setting. The field observations are complemented by laboratory investigations on the reactivity of PAH in fog systems, both heterogeneously and in the aqueous phase. Heterogeneously a novel reactor design is being tested to simulate fog systems and allow for repeat fog/smog cycles. A separate series of measurements investigated the processing of PAH in the aqueous phase in a solar simulator set-up.

Wang, Y.; Khadapkar, K.; Ehrenhauser, F. S.; Hutchings, J. W.; Wornat, M. J.; Valsaraj, K. T.; Herckes, P.

2010-07-01

85

The origin of the polycyclic aromatic hydrocarbons in meteorites  

NASA Astrophysics Data System (ADS)

Polycyclic aromatic hydrocarbons (PAHs) in C1 and C2 Carbonaceous Chondrites appear to be the product of a high-temperature synthesis. This observation counters a prevailing view that PAHs in meteorites are a thermal alternation product of preexisting aliphatic compounds, which in turn required the presence of low-temperature mineral phases such as magnetite and hydrated phyllosilicates for their formation. Such a process would necessarily lead to a more low-temperature assemblage of PAHs, as many low-temperature minerals and compounds are extant in meteorites. Ivuna, a C1 carbonaceous chondrite, has been shown to contain abundant amounts of the three-ring PAHs phenanthrene/anthracene, but no detectable levels of the two- and four-ring PAHs naphthalene and pyrene/fluoranthene. Ivuna and other C1 carbonaceous chondrites are known to have been extensively altered by water. The aqueous solubities of PAHs indicate that some PAHs would have been mobilized during the aqueous alteration phase in meteorite parent bodies. Model geochromatography experiments using crushed serpentine or beach sand as the solid phase and water for elution suggest that the complete separation of two, three, and four-ring PAHs could be expected to occur in the parent body of C1 carbonaceous chondrites. It is proposed that aqueous fluids driven by heat in the parent body of Ivuna migrated from the interior to the surface, in the process transporting, separating and concentrating PAHs at various zones in the parent body. The presence of indigenous PAHs and absence of indigenous amino acids in the H4 ordinary chondrite Forest Vale provides support for the contention that different processes and environments contributed to the synthesis of the organic matter in the solar system.

Wing, Michael R.; Bada, Jeffrey L.

1991-09-01

86

Atmospheric chlorinated polycyclic aromatic hydrocarbons in East Asia.  

PubMed

This study estimates atmospheric concentrations of chlorinated polycyclic aromatic hydrocarbons (ClPAHs) and polycyclic aromatic hydrocarbons (PAHs) in East Asia using a Gas Chromatograph with High Resolution Mass Spectrometer (GC-HRMS). ClPAHs are ubiquitously generated from PAHs through substitution, and some ClPAHs show higher aryl hydrocarbon receptor (AhR)-mediated activities than their parent PAHs. Atmospheric particles were collected using a high-volume air sampler equipped with a quartz-fiber filter. We determined the ClPAH concentrations of atmospheric particles collected in Japan (Sapporo, Sagamihara, Kanazawa, and Kitakyushu), Korea (Busan), and China (Beijing). The concentrations of ClPAHs were highest in the winter Beijing sample, where the total mean concentration was approximately 15-70 times higher than in the winter samples from Japan and Korea. The concentrations of ?19ClPAHs and ?9PAHs were significantly correlated in the Kanazawa and the Busan samples. This indicates that within those cities ClPAHs and PAHs share the same origin, implying direct chlorination of parent PAHs. Toxic equivalent concentrations (TEQs) of the total ClPAHs and PAHs were lowest in Kanazawa in the summer, reaching 1.18 and 2610fg-TEQm(-3) respectively, and highest in Beijing in the winter, reaching 627 and 4240000fg-TEQm(-3) respectively. PMID:24997898

Kakimoto, Kensaku; Nagayoshi, Haruna; Konishi, Yoshimasa; Kajimura, Keiji; Ohura, Takeshi; Hayakawa, Kazuichi; Toriba, Akira

2014-09-01

87

Lymphocyte aromatic hydrocarbon responsiveness in acute leukemia of childhood  

SciTech Connect

Aryl hydrocarbon hydroxylase (AHH) activity and inducibility were examined in mitogen-stimulated cultured lymphocytes from children with acute leukemia in remission, with nonleukemic malignancies, and with no family or personal history of malignant disease. Neither morphological differences nor differences in mitogen responsivelness were observed among the three sources of cells studied. Levels of constitutive and dibenzanthracene-induced AHH activity were found to be similar among the three groups by analysis of variance. However, when results were analyzed in terms of inducibility ratios, it was found that cells from leukemic children were significantly less inducible (p < 0.005) than cells from unaffected children or children with nonleukemic malignancies. The reason for this difference became apparent when statistical criteria were employed for the phenotypic separation of individuals who were highly aromatic hydrocarbon responsive and minimally responsive. A significantly larger proportion (p < 0.001) of leukemic children than unaffected children or children with nonleukemic malignancy were found to be minimally aromatic hydrocarbon responsive. Moreover, in patients with acute lymphoblastic leukemia relapsing while on therapy, longer durations of the first remission were correlated (r = 0.63, p < 0.05) with the highly inducible AHH phenotype.

Blumer, J.L. (Rainbow Babies and Children's Hospital, Cleveland, OH); Dunn, R.; Esterhay, M.D.; Yamashita, T.S.; Gross, S.

1981-12-01

88

The high-temperature oxidation of aromatic hydrocarbons  

NASA Technical Reports Server (NTRS)

Chemical mechanisms of the atmospheric pressure, high-temperature (875-1500 K) gas-phase oxidation of benzene, toluene, ethylbenzene, and propylbenzene are described and discussed. Oxidation trends evident from turbulent flow reactor experiments serve as the basis for the mechanisms of the oxidation of benzene and alkylated aromatics. The potential effects of very high temperatures and pressures on the chemistry of oxidation of aromatics are described. The oxidation of benzene and phenyl radical has been found to proceed in a stepwise C6-C5-C4 sequence. Species profiles obtained from flow-reactor experiments suggest that the oxidation of benzene and phenyl radical follows the generalized route via phenoxy, cyclopentadienyl and butadienyl radical. The oxidation of the C4 species branches into multiple pathways that yield copious amounts of ethylene and acetylene. Certain major trends are evident: the alkylated aromatics on initial attack either form styrene, benzyl radical or benzene. The styrene reacts further to produce a benzyl radical or benzene. The oxidation of an alkylated aromatic hydrocarbon appears eventually to reduce to the oxidation of either phenyl radical or benzene.

Brezinsky, K.

1986-01-01

89

Application of Nonionic Surfactant for the Bioremediation of Polycyclic Aromatic Hydrocarbons.  

E-print Network

??The effectiveness of nonionic surfactant addition on the bioremediation of polycyclic aromatic hydrocarbons was studied. Specifically, biological responses to synthetic surfactant addition and the surfactant… (more)

SEO, YOUNGWOO

2008-01-01

90

Differential mechanisms of cell death induced by nitro-polycyclic aromatic hydrocarbons.  

E-print Network

??Polycyclic aromatic hydrocarbons (PAHs) and nitro-PAHs are environmental pollutants formed during incomplete combustion of organic material, found attached to particulate matter (PM) in ambient air.… (more)

Asare, Nana Y. O.

2009-01-01

91

Composition, distribution, and characterization of polycyclic aromatic hydrocarbons in soil in Linfen, China  

SciTech Connect

A total of 10 surface soil samples representing the entire area of Linfen City were collected and analyzed for the presence of 16 polycyclic aromatic hydrocarbons. The total polycyclic aromatic hydrocarbon concentration ranged from 1.1 to 63.7 {mu} g g{sup -1}. Analysis of the sources of contamination revealed that polycyclic aromatic hydrocarbons in the soil were derived from combustion sources. Specifically, the primary source of polycyclic aromatic hydrocarbons was coal combustion, but the samples were also effected to varying degrees by traffic emissions. Furthermore, increased levels of contamination were observed in northeast Linfen due to the distribution of industrial plants.

Fu, S.; Cheng, H.X.; Liu, Y.H.; Xia, X.J.; Xu, X.B. [Chinese Academy of Sciences, Beijing (China)

2009-02-15

92

Polycyclic Aromatic Hydrocarbons (PAHs): Degradation and Fungal Biomass (Ergosterol) in Sediment with added Nitrogen.  

E-print Network

??White rot fungi, Pleurotus ostreatus, is capable of degrading a wide range of organic contaminants including PAHs. Bioremediating polycyclic aromatic hydrocarbons (PAH) contaminated river sediment… (more)

Osama, Mohammad

2009-01-01

93

Synthesis of polycyclic aromatic hydrocarbons in He nanodroplets  

NASA Astrophysics Data System (ADS)

Here we report the first mass spectrometric study of the synthesis of larger polycyclic aromatic hydrocarbon molecules (PAHs) out of weakly bound triphenylene agglomerates in cold helium droplets upon electron ionization. A highly abundant single reaction product is observed which indicates an extremely efficient and selective process. We propose that the synthesis of large molecules like fullerenes in interstellar clouds may proceed via similar reactions. Future work on different PAHs like benz[a]anthracene or chrysene will give more insight into this fascinating synthesis process.

Gschliesser, D.; Ferreira da Silva, F.; Bartl, P.; Denifl, S.; Scheier, P.

2012-11-01

94

Polycyclic aromatic hydrocarbons residues in sandstorm depositions in Beijing, China  

SciTech Connect

This study was conducted to determine the concentration of 16 polycyclic aromatic hydrocarbons (PAHs) in sandstorm depositions in Beijing, China. The PAH concentrations in 13 samples collected in Beijing ranged from 0.18 to 3.52 {mu} g g{sup -1}. Analysis of the sources of contamination revealed that the PAHs were derived from a coal combustion source, although various effects of traffic emissions were also observed. Furthermore, the PAH levels in Beijing tended to be higher in the southeast. Finally, the Nemerow composite index revealed that the degree of pollution in the sandstorm depositions varied widely among sampling sites.

Fu, S.; Li, K.; Xia, X.J.; Xu, X.B. [Chinese Academy of Sciences, Beijing (China)

2009-02-15

95

Photo-double-ionization mechanisms in aromatic hydrocarbons  

NASA Astrophysics Data System (ADS)

We have measured the ratios of doubly to singly charged molecular parent ions of benzene (partially deuterated), naphthalene, anthracene, pentacene, pyrrole, furan, selenophene, and coronene for photon energies ranging from threshold to the carbon K shell. The photon-energy dependence of the ratio curves has been analyzed and compared to each other for the above molecules. We conclude that two—and in some cases three—different photo-double-ionization mechanisms exist for aromatic hydrocarbons. One of the mechanisms is the formation of a two-electron pseudoparticle. This finding may be useful in the quest for understanding high-temperature superconductivity.

Hartman, T.; Jurani?, P. N.; Collins, K.; Reilly, B.; Makoutz, E.; Appathurai, N.; Wehlitz, R.

2013-06-01

96

Solubility of polycyclic aromatic hydrocarbons in supercritical carbon dioxide  

SciTech Connect

The equilibrium solubilities of three solid polycyclic aromatic hydrocarbons (acenaphthene, fluoranthene, and triphenylene) were determined at temperatures ranging from 308 K to 348 K and pressures from 121.6 to 354.6 bar in supercritical CO{sub 2}. The data were obtained by using a simple static sampling apparatus which was tested by measuring the solubility of naphthalene in compressed CO{sub 2}. The measured solubilities were correlated using a semiempirical model. The calculated results show satisfactory agreement with the experimental data.

Yamini, Y.; Bahramifar, N.

2000-02-01

97

Effects of co-occurring aromatic hydrocarbons on degradation of individual polycyclic aromatic hydrocarbons in marine sediment slurries  

SciTech Connect

Rates of polycyclic aromatic hydrocarbon (PAH) degradation and mineralization were influenced by preexposure to alternate PAHs and a monoaromatic hydrocarbon at relatively high (100 ppm) concentrations in organic-rich aerobic marine sediments. Prior exposure to three PAHs and benzene resulted in enhanced (/sup 14/C)naphthalene mineralization, while (/sup 14/C)anthracene mineralization was stimulated only by benzene and anthracene preexposure. Preexposure of sediment slurries to phenanthrene stimulated the initial degradation of anthracene. Prior exposure to naphthalene stimulated the initial degradation of phenanthrene but had no effect on either the initial degradation of mineralization of anthracene. For those compounds which stimulated (/sup 14/C)anthracene of (/sup 14/C)naphthalene mineralization, longer preexposures (2 weeks) to alternative aromatic hydrocarbons resulted in an even greater stimulation response. Enrichment with individual PAHs followed by subsequent incubation with one or two PAHs showed no alteration in degradation patterns due to the simultaneous presence of PAHs. The evidence suggests that exposure of marine sediments to a particular PAH or benzene results in the enhanced ability of these sediments to subsequently degrade that PAH as well as certain other PAHs. The enhanced degradation of a particular PAH after sediments have been exposed to it may result from the selection and proliferation of specific microbial populations capable of degrading it.

Bauer, J.E.; Capone, D.G.

1988-07-01

98

The effect of aromatization on the isotopic compositions of hydrocarbons during early diagenesis  

NASA Technical Reports Server (NTRS)

Polycyclic aromatic hydrocarbons with varying degrees of aromatization were isolated from the Eocene Messel Shale (Rheingraben, Germany). The high abundances of these compounds and their structural resemblances to cyclic triterpenoid lipids are consistent with derivation from microbial rather than thermal processes. Compounds structurally related to oleanane contain from five to nine double bonds; those within a series of aromatized hopanoids contain from three to nine. All are products of diagenetic reactions that remove hydrogen or methyl groups, and, in several cases, break carbon-carbon bonds to open rings. Aromatized products are on average depleted in 13C relative to possible precursors by l.2% (range: l.5% enrichment to 4% depletion, n = 9). The dependence of 13C content on the number of double bonds is not, however, statistically significant and it must be concluded that there is no strong evidence for isotopic fractionation accompanying diagenetic aromatization. Isotopic differences between series (structures related to ursane, des-A-ursane, des-A-lupane, des-A-arborane, and possibly, des-A-gammacerane are present) are much greater, indicating that 13C contents are controlled primarily by source effects. Fractionations due to chromatographic isotope effects during HPLC ranged from 0.1 to 2.8%.

Freeman, K. H.; Boreham, C. J.; Summons, R. E.; Hayes, J. M.

1994-01-01

99

Determination of polycyclic aromatic hydrocarbons in unfractionated solid solvent-refined coal by matrix isolation fluorescence spectrometry  

SciTech Connect

An untreated solid solvent-refined coal sample yields matrix isolation fluorescence spectra suitable for identification and determination of polycyclic aromatic hydrocarbons. Selective excitation of fluorescence in Shpol'skii matrices and background suppression using the time resolution capabilities of a dye-laser spectrometer permit the unambiguous identification of PAHs including benzo(a)pyrene. Determination of four polycyclic aromatic hydrocarbons (benzo(a)pyrene, perylene, benz(a)anthracene, and benzo(b)fluorene) in Solvent Refined Coal I is reported, as is the determination, by identical spectrometric technique, of the benzo(a)pyrene content of a NBS shale oil standard reference material. 5 figures, 2 tables.

Perry, M.B.; Wehry, E.L.; Mamantov, G.

1983-10-01

100

Polynuclear aromatic hydrocarbons in oyster tissue around three coastal marinas  

SciTech Connect

Marinas present the potential for introduction of various pollutants into the surrounding waters such as coliform bacteria, primary pathogens, heavy metals, and petroleum hydrocarbons. Little data have been presented specifically addressing the effects of recreational marinas on petroleum hydrocarbon levels or, for that matter, other constituent levels in oysters near those marinas. In order to obtain such data, a comprehensive assessment of water and oyster quality around three coastal marinas was conducted by the South Carolina Department of Health and Environmental control (SCDHEC) during 1983. Polynuclear aromatic hydrocarbons (PAH) were selected as the petroleum hydrocarbon fraction of interest since they are mainly of pyrogenic origin; have been shown to be the most toxic/carcinogenic fraction of oil; have been shown to affect the respiration and heart rates of mussels; and have been shown to be linked to neoplasia in clams and proliferative disorders in mussels. C. virginica was chosen as the mollusc of interest because of its widespread distribution in the estuaries of South Carolina, its importance as an economic and recreational resource, and its suitability as a sentinel organism for monitoring coastal pollution.

Marcus, J.M.; Stokes, T.P.

1985-12-01

101

MTBE and aromatic hydrocarbons in North Carolina stormwater runoff.  

PubMed

A total of 249 stormwater samples were collected from 46 different sampling locations in North Carolina over an approximate 1-year period and analyzed to identify land use types where fuel oxygenates and aromatic hydrocarbons may be present in higher concentrations and at greater frequency. Samples were analyzed by gas chromatography-mass spectrometry in ion selective mode to achieve a quantitation limit of 0.05 microg/l. m-,p-Xylene and toluene were detected in over half of all samples analyzed, followed by MTBE: o-xylene: 1,3,5-trimethylbenzene: ethylbenzene; and 1,2,4-trimethylbenzene. Benzene, DIPE, TAME and 1,2,3-trimethylbenzene were detected in < 10% of the samples analyzed. Median contaminant concentrations (when detected) varied from 0.07 microg/l for ethylbenzene to 0.11 microg/l for toluene. All of the locations with significantly higher contaminant concentrations were associated with direct runoff from a gas station or discharge of contaminated groundwater from a former leaking underground storage tank. For all of the aromatic hydrocarbons, the maximum observed contaminant concentrations were over an order of magnitude lower than current drinking water standards. PMID:11996377

Borden, Robert C; Black, David C; McBlief, Kathleen V

2002-01-01

102

Consensus sediment quality guidelines for polycyclic aromatic hydrocarbon mixtures  

SciTech Connect

Sediment quality guidelines (SQGs) for polycyclic aromatic hydrocarbons (PAHs) have been derived from a variety of laboratory, field, and theoretical foundations. They include the screening level concentration, effects ranges-low and -median, equilibrium partitioning concentrations, apparent effects threshold, {Sigma}PAH model, and threshold and probable effects levels. The resolution of controversial differences among the PAH SQGs lies in an understanding of the effects of mixtures. Polycyclic aromatic hydrocarbons virtually always occur in field-collected sediment as a complex mixture of covarying compounds. When expressed as a mixture concentration, that is, total PAH (TPAH), the guidelines form three clusters that were intended in their original derivations to represent threshold (TEC = 290 {micro}g/g organic carbon [OC]), median (MEC = 1,800 {micro}g/g OC), and extreme (EEC = 10,000 {micro}g/g OC) effects concentrations. The TEC/MEC/EEC consensus guidelines provide a unifying synthesis of other SQGs, reflect causal rather than correlative effects, account for mixtures, and predict sediment toxicity and benthic community perturbations at sites of PAH contamination. The TEC offers the most useful SQG because PAH mixtures are unlikely to cause adverse effects on benthic ecosystems below the TEC.

Swartz, R.C. [Environmental Protection Agency, Newport, OR (United States)

1999-04-01

103

Polycyclic aromatic hydrocarbons in clams Ruditapes decussatus (Linnaeus, 1758).  

PubMed

The concentration of sixteen individual polycyclic aromatic hydrocarbons (PAHs) was measured in the clam Ruditapes decussatus whole soft tissues from several places of the Ria Formosa lagoon (Portugal). Total PAH (tPAH) concentrations were higher in the summer (August) and winter (January) than in the other months and the distribution pattern of the individual PAHs was generally dominated by the 4 aromatic ring PAHs, followed by the 2 + 3 aromatic rings PAHs. Benzo[a]anthracene and acenaphthene were the most representative PAHs of the two fractions. Principal components analysis (PCA) revealed that, in the Ria Formosa, seasonal variations are more important than spatial variations, due to changes in PAH source. These sources ranged from petrogenic to pyrolytic or a mixture of both. The origin of clam PAHs was also assessed by partial least squares (PLS) analysis using nineteen different PAH signatures, taken from the literature. It was possible to identify boat traffic, especially in the summer, as one of the most relevant PAH sources to the Ria Formosa. The influence of boat traffic was revealed by several signatures including diesel soot, oil and weathered oil and a mixture of different individual PAHs usually found in harbour sediments. Other relevant sources included combustion of organic matter such as forest fires and diverse domestic activities, occurring mainly in the summer. Most of the clams were considered safe for human consumption, except for some point samples, which presented unusually high PAH concentrations, suggesting the need for a regular survey of PAHs in clam tissues. PMID:17285162

Barreira, Luísa A; Mudge, Stephen M; Bebianno, Maria J

2007-02-01

104

UV Resonance Raman Characterization of Polycyclic Aromatic Hydrocarbons in Coal Liquid Distillates*  

E-print Network

-950°F) was collected from the plant and subsequently vacuum distilled at the Pittsburgh EnergyUV Resonance Raman Characterization of Polycyclic Aromatic Hydrocarbons in Coal Liquid Distillates used to characterize the polycyclic aromatic hydrocarbon composition of a series of distillates of coal

Asher, Sanford A.

105

Inversion and rotation processes involving non-planar aromatic compounds catalyzed by extended polycyclic aromatic hydrocarbons  

NASA Astrophysics Data System (ADS)

Using accurate quantum chemical calculations, we show that extended planar polycyclic aromatic hydrocarbons (PAHs) can efficiently catalyze a range of chemical processes involving non-planar aromatic systems. These include (i) bowl-to-bowl inversion of curved PAHs (e.g. corannulene and sumanene), (ii) ‘flip-flop' inversion of helicenes (e.g. benzo[c]phenanthrene), and (iii) rotation about the Phsbnd Ph bond in biphenyls. Non-covalent ?-? interactions between the planar catalyst and the substrate stabilize the planar transition structures to a greater extent than they stabilize the non-planar reactants. These result in surprisingly large catalytic enhancements (namely, the reaction barrier heights are reduced by 21-63% of the uncatalyzed reaction barriers).

Karton, Amir

2014-10-01

106

CHEMICAL INDUCTION OF TUMORS IN OYSTERS BY A MIXTURE OF AROMATIC AND CHLORINATED HYDROCARBONS, AMINES, AND METALS  

EPA Science Inventory

Tumors were induced in eastern oysters (Crassotrea virginica) by a mixture f aromatic hydrocarbons, an aromatic amine, polychlori-nated biphenyls, chlorinated hydrocarbons, a nitrosoamine and heavy metals. idney and nteric tumors developed in oysters following exposure to a mixtu...

107

[Extraction characteristics of sequential accelerated solvent extraction for polycyclic aromatic hydrocarbons in environmental mediums].  

PubMed

Polycyclic aromatic hydrocarbons (PAHs) in two soils, two sediments and an shale from the Pearl River Delta were extracted by sequential accelerated solvent extraction (ASE) with each of four different organic solvents for three times. PAHs in the first extract accounts for more than half of their total contents, and toluene displays the best extraction performance among the four employed solvents. For a given sample the source diagnostic ratios of PAHs in sequential ASE with each solvent are very similar, suggesting the validity of those ratios in source judgement by different extraction methods. PMID:20187409

Ma, Xiao-xuan; Ran, Yong

2009-12-01

108

Aliphatic hydrocarbon and polycyclic aromatic hydrocarbon geochemistry of twelve major rivers in the Northwest Territories  

SciTech Connect

Suspended sediment and water samples collected from twelve major rivers in the Northwest Territories were analyzed for aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) to assess the sources and transport of hydrocarbons entering the Arctic Ocean. Three stations on the Mackenzie River and one station near the mouth of eleven other northern rivers were selected for sampling. Samples were collected on the Mackenzie River on four occasions to characterize spring, summer and fall flow conditions and once on the remaining eleven rivers during high flow conditions. The Mackenzie River is distinctively different then the other eleven rivers. Naturally occurring hydrocarbons predominate in the river. These hydrocarbons include biogenic alkanes, diagenic PAHs, petrogenic alkanes, and PAHs from oil seeps and/or bitumens. Anthropogenic inputs of PAHs are low as indicated by low concentrations of combustion PAHs. Alkyl PAH distributions indicate that a significant component of the lower molecular weight PAH fraction is petrogenic. The majority of the high molecular weight PAHs, together with the petrogenic PAHs have a principal source in the Mackenzie River.

Backus, S. [Backus Consulting, Stoney Creek, Ontario (Canada); Swyripa, M.; Peddle, J. [Department of Indian and Northern Development, Yellowknife, Northwest Territories (Canada); Jeffries, D.S. [National Water Research Inst., Burlington, Ontario (Canada)

1995-12-31

109

Aromatic hydrocarbons, diamonds, and fullerenes in interstellar space: puzzles to be solved by laboratory and theoretical astrochemistry  

Microsoft Academic Search

New research is presented, and previous research is reviewed, on the emission and absorption of interstellar aromatic hydrocarbons. Emission from aromatic hydrocarbons dominates the mid-infrared emission of many galaxies, including our own Milky Way galaxy. Only recently have aromatic hydrocarbons been observed in absorption in the interstellar medium, along lines of sight with high column densities of interstellar gas and

Kristen Sellgren

2001-01-01

110

Emission of polycyclic aromatic hydrocarbons in China by county  

SciTech Connect

Quantitative relationships among social, economic, and climate parameters, and energy consumption for Chinese provinces, provide data for regression models' estimated rates of energy consumption and emission of polycyclic aromatic hydrocarbons (PAHs) by county. A nonlinear model was used for domestic coal combustion with total population and annual mean temperature as independent variables. Linear regression models were utilized for all other types of fuel consumption. Monte Carlo simulation demonstrated that emission factors, rather than the regression modeling, constitute the main source of uncertainty in prediction. Models were validated using available energy data of several northern and southern counties of China from the literature. The total PAHs produced by each county is approximately equivalent to the sum of the total emission from energy, coke, and aluminum production. 25 refs., 8 figs.

Yanxu Zhang; Shu Tao; Jun Cao; Raymond M. Coveney III [Peking University, Beijing (China). Laboratory for Earth Surface Processes, College of Environmental Sciences

2007-02-15

111

Relative decay index and sources of polycyclic aromatic hydrocarbons  

NASA Astrophysics Data System (ADS)

An optimized method for the analysis of polycyclic aromatic hydrocarbons (PAH) in atmospheric aerosols with short sampling times (1h) has been used to determine the daily variations of PAH in the atmosphere. Of the various physicochemical parameters controlling the disappearance of PAH, the most important seem to be the thermic dependence and the chemical reactions with gaseous pollutants ( NOx, O 3, HNO 3, OH). The RDI is used to identify the different sources of urban pollution: domestic heating, vehicle traffic (petrol and diesel), refineries, foundries, incinerators and power stations (coal, gas and oil) and to quantify the results for standard conditions. The characteristic concentration ratios from each source are often different from those in the literature, where the data are based on long sampling times and are affected by PAH reactivity differences. The results obtained are parameters for setting up a mathematical model for calculating concentrations of PAH at any receptor site.

Masclet, P.; Mouvier, G.; Nikolaou, K.

112

Sequential extraction of polycyclic aromatic hydrocarbons using subcritical water.  

PubMed

A rapid sequential subcritical (superheated) water extraction method for polycyclic aromatic hydrocarbons (PAHs) in contaminated soil and sediment is presented. Decreasing the polarity of water by successive increase of the extraction temperature from 50 degrees C to 200 degrees C at the moderate pressure (10.3MPa) enabled selective, non-exhaustive extractions to be performed. Concurrent with increasing temperatures to 150 degrees C there was an increase in PAH extraction efficiencies. For the majority of determinations no significant differences between extractions at 150 degrees C and 200 degrees C were observed. Varied extraction efficiencies of PAHs at the same extraction conditions reflected dissimilarities between environmental matrices investigated. Selective subcritical water extraction of PAHs was proportional to their octanol-water partition coefficients. This technique may be applicable in evaluation of risks associated with PAH contaminated sites and in assessments of their bioremediation potential. PMID:20018343

Latawiec, Agnieszka E; Reid, Brian J

2010-02-01

113

Halogenated persistent organic pollutants and polycyclic aromatic hydrocarbons in food.  

PubMed

During recent years, mass spectrometry (MS) and hyphenated chromatographic instrumentation and techniques have been a subject of dramatic developments, resulting in the introduction of various useful tools for the analysis of halogenated persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAHs) in food and environmental matrices. This chapter describes state-of-the-art in the field of MS as a primary detection tool for the halogenated POPs and PAHs previously separated using either gas chromatography (GC) or liquid chromatography (LC). Since sample preparation practice plays a crucial role for obtaining optimal performance characteristics of a particular analytical method, a brief overview of sample extraction and clean-up procedures in the POPs/PAHs analysis is also briefly outlined. PMID:21643916

Cajka, Tomas; Hajslova, Jana

2011-01-01

114

Mutagenicity of nitrated polycyclic aromatic hydrocarbons: a QSAR investigation.  

PubMed

Quantitative structure-activity relationship studies were performed to describe and predict the mutagenic activity of a set of 48 nitrated polycyclic aromatic hydrocarbons. From a larger pool of molecular descriptors (topological indices) we arrived at much a smaller set consisting of three correlating parameters. Such a variable selection is made using ncss software in that successive regressions were attempted using maximum-R(2) method. The results are critically discussed using a variety of statistical parameters. Our results have shown that connectivity and shape type indices together with the distance-based Wiener index (W) play a dominating role in modelling of mutagenicity (logTA100). The predictive ability of the models is discussed on the basis of cross-validated parameters. PMID:18248351

Singh, Jyoti; Singh, Shalini; Shaik, Basheerulla; Deeb, Omar; Sohani, Neena; Agrawal, Vijay K; Khadikar, Padmakar V

2008-03-01

115

NMR shifts for polycyclic aromatic hydrocarbons from first-principles  

SciTech Connect

We present first-principles, density-functional theory calculations of the NMR chemical shifts for polycyclic aromatic hydrocarbons, starting with benzene and increasing sizes up to the one- and two-dimensional infinite limits of graphene ribbons and sheets. Our calculations are performed using a combination of the recently developed theory of orbital magnetization in solids, and a novel approach to NMR calculations where chemical shifts are obtained from the derivative of the orbital magnetization with respect to a microscopic, localized magnetic dipole. Using these methods we study on equal footing the 1H and 13C shifts in benzene, pyrene, coronene, in naphthalene, anthracene, naphthacene, and pentacene, and finally in graphene, graphite, and an infinite graphene ribbon. Our results show very good agreement with experiments and allow us to characterize the trends for the chemical shifts as a function of system size.

Thonhauser, Timo; Ceresoli, Davide; Marzari, Nicola N.

2009-09-03

116

Simulated transport of polycyclic aromatic hydrocarbons in artificial streams  

SciTech Connect

A model was constructed to predict the pattern of flow and accumulation of three polycyclic aromatic hydrocarbons (PAH) (anthracene, naphthalene, and benzo(a)pyrene) in artificial streams located on the Savannah River Plant near Aiken, South Carolina. Predictions were based upon the premise that the fundamental chemistry of individual PAH contains useful information for predictive purposes. Model processes included volatilization, photolysis, sorption to sediments and particulates, and net accumulation by biota. Simulations of anthracene transport were compared to results of an experiment conducted in the streams. The model realistically predicted the concentration of dissolved anthracene through time and space. Photolytic degradation appeared to be a major pathway of anthracene flux from the streams.

Bartell, S.M.; Landrum, P.F.; Giesy, J.P.; Leversee, G.J.

1981-01-01

117

Accumulation of polycyclic aromatic hydrocarbons in acid sensitive lakes  

SciTech Connect

Polycyclic aromatic hydrocarbon concentrations and fluxes were measured in {sup 210}Pb dated sediment cores taken from nine lakes in four regions identified as susceptible to acidification. Calculated PAH accumulations were compared with historic S emissions, accumulation of sedimentary S, and anthropogenic metal accumulations to determine if PAH could be used as an indicator of combustion-derived sulfate deposition. Comparisons between regions indicated that the Adirondacks have a significantly higher burden of PAH than do northern New England, the northern Great Lakes States, and northern Florida. This difference likely results from significant upwind PAH sources to the Adirondack lakes. Detailed investigation of the largest lake in the study set, Big Moose Lake, indicates that PAH may serve as conservative, combustion indicators in large lakes. In this lake, PAH fluxes and concentrations were significantly correlated with historical S emission rates. These data suggest that PAH measured in sediment cores from large lakes can serve as indicators of past combustion production deposition.

Furlong, E.T.; Cessar, L.R.; Hites, R.A. (Indiana Univ., Bloomington (USA))

1987-11-01

118

Metabolism of polycyclic aromatic hydrocarbons in the aquatic environment  

SciTech Connect

During the past decade, knowledge of polycyclic aromatic hydrocarbons (PAH) in the aquatic environment has advanced substantially to encompass studies of bioavailability, metabolism, subsequent toxic effects, and their ecological consequences. In this book, recent advances in the areas of PAH biogeochemistry and bioaccumulation, microbial degradation, enzymes of activation and detoxication, metabolism of PAH, and laboratory and field studies on carcinogenic/toxic effects, are presented. Additionally, important similarities and differences in metabolism of PAH by aquatic and terrestrial organisms are discussed. These chapters also illustrate that although considerable progress has been made in certain areas of PAH metabolism in the aquatic environment, the field is relatively unexplored and many exciting possibilities exist for future investigations. Separate abstracts are included for 9 chapters in this book for inclusion in the appropriate data bases.

Varanasi, U. (ed.)

1989-01-01

119

Polycyclic Aromatic Hydrocarbons and the Diffuse Interstellar Bands: a Survey  

NASA Technical Reports Server (NTRS)

We discuss the proposal relating the origin of some of the diffuse interstellar bands (DIBs) to neutral and ionized polycyclic aromatic hydrocarbons (PAHs) present in interstellar clouds. Laboratory spectra of several PAHs, isolated at low temperature in inert gas matrices, are compared with an extensive set of astronomical spectra of reddened, early type stars. From this comparison, it is concluded that PAN ions are good candidates to explain some of the DIBs. Unambiguous assignments are difficult, however, due to the shift in wavelengths and the band broadening induced in the laboratory spectra by the solid matrix. Definitive band assignments and, ultimately, the test of the of the proposal that PAH ions carry some of the DIB must await the availability of gas-phase measurements in the laboratory. The present assessment offers a guideline for future laboratory experiments by allowing the preselection of promising PAH molecules to be studied in jet expansions.

Salama, F.; Galazutdinov, G. A.; Krelowski, J.; Allamandola, L. J.; Musaev, F. A.; DeVincenzi, Donald L. (Technical Monitor)

1999-01-01

120

Polycyclic Aromatic Hydrocarbons in Electrocautery Smoke during Peritonectomy Procedures  

PubMed Central

Objective. This study identified and quantified polycyclic aromatic hydrocarbons (PAHs) in electrocautery smoke during 40 peritonectomy procedures and investigated any correlations and/or differences between levels of PAHs and perioperative variables. Methods. PAHs were measured in personal and stationary sampling by 40?mm Millipore cassettes, for adsorption of both gaseous and particle-bound PAHs. Results. All 16 USEPA priority pollutant PAHs were detected during peritonectomy procedures, naphthalene being the most abundant. For the only two PAHs with Swedish occupational exposure limits (OELs), benzo[a]pyrene and naphthalene, limits were never exceeded. Amount of bleeding was the only perioperative variable that correlated with levels of PAHs. Conclusions. Low levels of PAHs were detected in electrocautery smoke during peritonectomy procedures, and an increased amount of bleeding correlated with higher levels of PAHs. For evaluation of long-term health effects, more studies are needed. PMID:22685482

Naslund Andreasson, Sara; Mahteme, Haile; Sahlberg, Bo; Anundi, Helena

2012-01-01

121

Heterogeneous catalyzed benzylic acetoxylation of methylated aromatic hydrocarbons  

SciTech Connect

The palladium-catalyzed acetoxylation of toluene to benzyl acetate is highly dependent on particle size. The rate of reaction is highest with 30--35 [Angstrom] particles corresponding to a 0.33 dispersion. Catalysts prepared and reduced by controlled methods before being contacted with the reaction medium, ex situ catalysts, were found to yield lower reaction rates than catalysts prepared in the reaction medium, in situ. Potassium ion-encapsulation in palladium during in situ preparation is a possible explanation for this result. Tin is required to reduce Pd[sup 2+] to Pd[sup 0] in the in situ system, but is not required for the ex situ catalyst. The improvement in activity of the ex situ catalyst in the presence of tin may be due to the reducibility of Sn[sup 4+] to Sn[sup 2+] during oxygen-poor regimes. Results obtained with diverse methylated aromatic hydrocarbons indicate that the aromatic ring interactions with the palladium surface via [pi]-donation before oxidation occurs. 37 refs., 7 figs., 5 tabs.

Benazzi, E.; Mimoun, H.; Cameron, C.J. (Institut Francais du Petrole, Rueil-Malmaison (France))

1993-04-01

122

Alkyl polycyclic aromatic hydrocarbons emissions in diesel/biodiesel exhaust  

NASA Astrophysics Data System (ADS)

Polycyclic aromatic hydrocarbons (PAHs) are widely studied in environmental matrices, such as air, water, soil and sediment, because of their toxicity, mutagenicity and carcinogenicity. Because of these properties, the environmental agencies of developed countries have listed sixteen PAHs as priority pollutants. Few countries have limits for these compounds for ambient air, but they only limit emissions from stationary and mobile sources and occupational areas. There are several studies to specifically address the 16 priority PAHs and very little for the alkyl PAHs. These compounds are more abundant, more persistent and frequently more toxic than the non-alkylated PAHs, and the toxicity increases with the number of alkyl substitutions on the aromatic ring. In this study, a method was developed for the analysis of PAHs and alkyl PAHs by using a GC-MS and large injection volume injection coupled with program temperature vaporisation, which allows for limits of detection below 1.0 ng ?L-1. Several variables were tested, such as the injection volume, injection velocity, injector initial temperature, duration of the solvent split and others. This method was evaluated in samples from particulate matter from the emissions of engines employing standard diesel, commercial diesel and biodiesel B20. Samples were collected on a dynamometer bench for a diesel engine cycle and the results ranged from 0.5 to 96.9 ng mL-1, indicating that diesel/biodiesel makes a significant contribution to the formation of PAHs and alkyl PAHs.

Casal, Carina S.; Arbilla, Graciela; Corrêa, Sergio M.

2014-10-01

123

LARGE ABUNDANCES OF POLYCYCLIC AROMATIC HYDROCARBONS IN TITAN'S UPPER ATMOSPHERE  

SciTech Connect

In this paper, we analyze the strong unidentified emission near 3.28 {mu}m in Titan's upper daytime atmosphere recently discovered by Dinelli et al. We have studied it by using the NASA Ames PAH IR Spectroscopic Database. The polycyclic aromatic hydrocarbons (PAHs), after absorbing UV solar radiation, are able to emit strongly near 3.3 {mu}m. By using current models for the redistribution of the absorbed UV energy, we have explained the observed spectral feature and have derived the vertical distribution of PAH abundances in Titan's upper atmosphere. PAHs have been found to be present in large concentrations, about (2-3) Multiplication-Sign 10{sup 4} particles cm{sup -3}. The identified PAHs have 9-96 carbons, with a concentration-weighted average of 34 carbons. The mean mass is {approx}430 u; the mean area is about 0.53 nm{sup 2}; they are formed by 10-11 rings on average, and about one-third of them contain nitrogen atoms. Recently, benzene together with light aromatic species as well as small concentrations of heavy positive and negative ions have been detected in Titan's upper atmosphere. We suggest that the large concentrations of PAHs found here are the neutral counterpart of those positive and negative ions, which hence supports the theory that the origin of Titan main haze layer is located in the upper atmosphere.

Lopez-Puertas, M.; Funke, B.; Garcia-Comas, M. [Instituto de Astrofisica de Andalucia (CSIC), E-18080 Granada (Spain); Dinelli, B. M. [ISAC-CNR, I-40129 Bologna (Italy); Adriani, A.; D'Aversa, E. [IAPS-INAF, I-00133 Rome (Italy); Moriconi, M. L. [ISAC-CNR, I-00133 Rome (Italy); Boersma, C.; Allamandola, L. J., E-mail: puertas@iaa.es [NASA Ames Research Center, Moffett Field, CA 94035-1000 (United States)

2013-06-20

124

Biodegradation of aromatic hydrocarbons by aquifer microorganisms under denitrifying conditions  

SciTech Connect

Laboratory tests were conducted to evaluate whether denitrification would be a suitable alternative for biorestoration of an aquifer contaminated with JP-4 jet fuel. Microcosms were prepared from uncontaminated and contaminated aquifer material, amended with nitrate, nutrients, and aromatic hydrocarbons, and incubated under a nitrogen atmosphere at 12 C. With uncontaminated core material, there was no observable lag period prior to removal of toluene whereas 30 days was required before biodegradation commenced for xylenes, ethylbenzene, and 1,2,4-trimethylbenzene. An identical test with contaminated aquifer material exhibited not only much longer lag periods but decreased rates of biodegradation; benzene, ethylbenzene, and o-xylene were not significantly degraded within the 6-month time period even though active denitrification occurred at this time. First-order biodegradation rate constants ranged from 0.016 to 0.38/day for uncontaminated core material and from 0.022 to 0.067/day for contaminated core material. Tests with individual compounds in uncontaminated core indicated that benzene and m-xylene inhibited the basal rate of denitrification. These data demonstrate that several aromatic compounds are degraded under denitrifying conditions, but rates of biodegradation may be lower in material contaminated with JP-4 jet fuel.

Hutchins, S.R.; Sewell, G.W.; Kovacs, D.A.; Smith, G.A.

1991-01-01

125

Biodegradation of aromatic hydrocarbons by aquifer microorganisms under denitrifying conditions  

SciTech Connect

A series of laboratory tests were conducted to evaluate whether denitrification would be a suitable alternative for biorestoration of an aquifer contaminated with JP-4 jet fuel. Microcosms were prepared from both uncontaminated and contaminated aquifer material from the site, in an anaerobic glovebox, amended with nitrate, nutrients, and aromatic hydrocarbons, and incubated under a nitrogen atmosphere at 12C. With uncontaminated core material, there was no observable lag period prior to removal of toluene whereas 30 days was required before biodegradation commenced for xylenes, ethylbenzene, and 1,2,4-trimethylbenzene. An identical test with contaminated aquifer material exhibited not only much longer lag periods but decreased rates of biodegradation; benzene, ethylbenzene, and o-xylene were not significantly degraded within the 6-month time period even though active denitrification occurred at this time. First-order biodegradation rate constants ranged from 0.016 to 0.38 day{sup {minus}1} for uncontaminated core material and from 0.022 to 0.067 day{sup {minus}1} for contaminated core material. Tests with individual compounds in uncontaminated core indicated that benzene and m-xylene inhibited the basal rate of denitrification. These data demonstrate that several aromatic compounds can be degraded under denitrifying conditions, but rates of biodegradation may be lower in material contaminated with JP-4 jet fuel.

Hutchins, S.R.; Sewell, G.W.; Smith, G.A. (Environmental Protection Agency, Ada, OK (USA)); Kovacs, D.A. (NSI Technology Services, Ada, OK (USA))

1991-01-01

126

Inhibitory effects of polycyclic aromatic hydrocarbons (PAHs) on photosynthetic performance are not related to their aromaticity.  

PubMed

Polycyclic aromatic hydrocarbons (PAHs) are very toxic and highly persistent environmental pollutants which accumulate in soil and affect growth of the plants adversely. This study aims to investigate inhibitory effects of 3 major PAH particularly on photosynthetic processes in Arabidopsis thaliana grown in soil treated with PAH. The 3 PAH chosen differ from each other in aromaticity (number of rings) comprising their structure (2 rings: naphthalene, 3 rings: anthracene and 4 rings: pyrene). Several growth parameters and Chlorophyll a fluorescence was monitored in PAH treated plants. BN-PAGe analysis was done in order to get information about change in the protein conformation. PAH treatment led to increased value of Fo which collaborated with increase in the amount of free LHC as seen through BN-Page analysis. Thus PAH were found to inhibit PS II photochemistry and caused distinct change in pigment composition. However the results led us to infer that 3-ring anthracence is more inhibitory as compared to 2-ring naphthalene and 4-ring pyrene. This indicates that aromaticity of PAH is unrelated to their response on photosynthetic processes. PMID:24793324

Jajoo, Anjana; Mekala, Nageswara Rao; Tomar, Rupal Singh; Grieco, Michele; Tikkanen, Mikko; Aro, Eva-Mari

2014-08-01

127

Autothermal reforming of aliphatic and aromatic hydrocarbon liquids  

NASA Technical Reports Server (NTRS)

Results are presented from a study of the autothermal reforming of paraffins and aromatics over nickel catalysts. The trials were performed to examine the carbon products that appear when steam is passed over hydrocarbon liquids to form H2-rich gases, i.e., the autothermal process (ATR). Attention was given to n-hexane, n-tetradecane, benzene, and benzene solutions of naphthalene with reactant preheat to 1000-1150 F. The carbon-formation limit was sought as a function of the steam-to-carbon and oxygen to carbon molar ratios at constant pressure and the preheat temperatures. The catalyst bed was examined after each trial to identify the locations and types of carbon formed using SEM, thermal gravimetric analysis, and X ray diffraction techniques. The hydrocarbon fuels each had a separate temperature and reaction profile, as well as carbon formation characteristics. No carbon formation was observed in the upper layer of the reactor bed, while both gas phase and surface-grown deposits were present in the lower part. The results are concluded of use in the study of No. 2 fuel oil for ATR feedstock.

Flytzani-Stephanopoulos, M.; Voecks, G. E.

1983-01-01

128

Effect of bioremediation on polycyclic aromatic hydrocarbon residues in soil  

SciTech Connect

Soil contamination (60 mg/g of soil) by a diesel oil (DO) spill was simulated in outdoor lysimeter units and the effect of bioremediation treatment consisting of liming, fertilization, and tilling on the persistence of polycyclic aromatic hydrocarbon (PAH) components of DO was measured. After solvent extraction from soil and class separation on silica gel, PAH components were identified and partially quantified by GC-ITD analysis. Residual mutagenicity and acute toxicity of the contaminated soil was also assessed by Ames and Microtox tests. Bioremediation treatment, while increasing the rate of total hydrocarbon degradation, had an even greater effect on PAH persistence, almost completely eliminating these compounds in 12 weeks. Without bioremediation, 12.5-32.5% of the higher molecular weight PAH were still present at 12 weeks. Mutagenicity and toxicity tests corroborated the above results. After substantial initial mutagenicity and toxicity, the contaminated soil approached the background level of uncontaminated soil after 12 weeks of bioremediation. Detoxification was complete in 20 weeks.

Wang, Xiaoping; Yu, Xiaobing; Bartha, R. (Rutgers, The State Univ. of New Jersey, New Brunswick (USA))

1990-07-01

129

Diversity of metabolic capacities among strains degrading polycyclic aromatic hydrocarbons  

SciTech Connect

Strains of Pseudomonas and Rhodococcus genera were isolated for their capacity to use, as a sole carbon and energy source, one of the following polycyclic aromatic hydrocarbons (PAHs): naphthalene (NAP), fluorene (FLU), phenanthrene (PHE), anthracene (ANT), fluoranthene (FLT), and pyrene (PYR). The range of PAHs supporting growth of these pure strains was usually restricted, but several other hydrocarbons were used by Rhodococcus sp. All strains could grow on simple organic acids. Maximal specific growth rates ({mu}{sub max}) of all strains on their PAH growth substrates were determined by respirometry. No clear relationships between {mu}{sub max} values and the molecular weight or water solubility of PAHs were apparent, but Pseudomonas sp. exhibited the highest {mu}{sub max} values. Carbon balances for PAH biodegradation were established. Differences between strains were observed, but high mineralization rates and low production of soluble metabolites were obtained for all PAHs. Bacterial biomass represented 16% to 35% of the carbon consumed. Strain diversity was also apparent in the interactions observed in the degradation of a mixture of two PAHs by individual strains, which often involved inhibition of PAH substrate degradation, with or without cometabolization of the second PAH.

Bouchez, M.; Besnaienou, B. [Commissariat a l`Energie Atomique, Saint Paul Lez Durance (France). Centre de Cadarache; Blanchet, D.; Vandecasteele, J.P. [Inst. Francais du Petrole, Rueil-Malmaison (France)

1995-12-31

130

Effects of sulfur and aromatic contents in gasoline on motorcycle emissions  

NASA Astrophysics Data System (ADS)

By investigating the effect of sulfur and aromatic contents in gasoline on the criteria pollutant emissions [CO, total hydrocarbons (THCs), and NO x] and on air toxics in the exhaust from a non-catalyst four-stroke motorcycle engine, inferences can be made concerning the effect of fuel composition on motorcycle emissions. The fuels were blended with different contents of sulfur (40 and 150 ppmw) and aromatics (20 and 30 vol%). The data indicate that the sulfur content does not correlate with the emissions of the criteria pollutants from the catalyst free engine. Instead, lowering aromatic content in gasoline reduced the THC emission by over 30%, especially in the cruising test. The NO x emission, however, showed an inverse correlation with the aromatic content in gasoline. While a reduction of aromatic content in gasoline may decrease emissions of benzene and toluene, it will increase the emission of aldehyde. Since the percentage changes of emission factor of THC and air toxics in the motorcycle were larger than those in passenger cars, the benefit of emission reduction due to fuel composition changes in motorcycles may have significant impacts in health risk analysis.

Yao, Yung-Chen; Tsai, Jiun-Horng; Chang, An-Lin; Jeng, Fu-Tien

131

AMENDMENT OF SEDIMENTS WITH A CARBONACEOUS RESIN REDUCES BIOAVAILABILITY OF POLYCYCLIC AROMATIC HYDROCARBONS  

EPA Science Inventory

A series of laboratory and field test studies were conducted to evaluate the effectiveness of Ambersorb, a carbonaceous resin, in reducing bioavailability of polycyclic aromatic hydrocarbons (PAHs) in contaminated sediments collected from the field. Amending contaminated sediment...

132

QSARS FOR PREDICTING REDUCTIVE TRANSFORMATION RATE CONSTANTS OF HALOGENATED AROMATIC HYDROCARBONS IN ANOXIC SEDIMENT SYSTEMS  

EPA Science Inventory

Quantitative structure-activity relationships (QSARs) are developed relating initial and final pseudo-first-order disappearance rate constants of 45 halogenated aromatic hydrocarbons in anoxic sediments to four readily available molecular descriptors: the carbon-halogen bond stre...

133

COMPUTATIONAL METHODS FOR STUDYING THE INTERACTION BETWEEN POLYCYCLIC AROMATIC HYDROCARBONS AND BIOLOGICAL MACROMOLECULES  

EPA Science Inventory

Computational Methods for Studying the Interaction between Polycyclic Aromatic Hydrocarbons and Biological Macromolecules . The mechanisms for the processes that result in significant biological activity of PAHs depend on the interaction of these molecules or their metabol...

134

Black carbon in marine sediments : quantification and implications for the sorption of polycyclic aromatic hydrocarbons  

E-print Network

Sorption is a key factor in determining the fate of polycyclic aromatic hydrocarbons (PAHs) in the environment. Here, PAH sorption is proposed as the sum of two mechanisms: absorption into a biogenic, organic carbon (OC) ...

Accardi-Dey, AmyMarie, 1976-

2003-01-01

135

STUDIES ON BIOREMEDIATION OF POLYCYCLIC AROMATIC HYDROCARBON-CONTAMINATED SEDIMENTS: BIOAVAILABILITY, BIODEGRADABILITY, AND TOXICITY ISSUES  

EPA Science Inventory

The widespread contamination of aquatic sediments by polycyclic aromatic hydrocarbons (PAHs) has created a need for cost-effective bioremediation processes, on which the bioavailability and the toxicity of PAHs often have a significant impact. This research investigated the biode...

136

ASSAYING PARTICLE-BOUND POLYCYCLIC AROMATIC HYDROCARBONS (PAH) FROM ARCHIVED PM2.5 FILTERS  

EPA Science Inventory

Airborne particulate matter contains numerous organic species, including several polycyclic aromatic hydrocarbons (PAHs) that are known or suspected carcinogens. Existing methods for measuring airborne PAHs are complex and costly, primarily because they are designed to collect...

137

Metabolism of mixtures of polycyclic aromatic hydrocarbons (PAHs) by Cunninghamella elegans  

E-print Network

Polycyclic aromatic hydrocarbons (PAHs) are environmentally significant compounds due to the toxicity of some members. They are ubiquitous and are persistent bioaccumulative toxins(PBTs). The toxicity of PAHs represents a risk to human health...

Olatubi, Oluwaseun Alfred

2007-04-25

138

Bacterial mutagenicity of polycyclic aromatic hydrocarbons in reconstituted mixtures and crude coal tar extracts and fractions  

E-print Network

Although polycyclic aromatic hydrocarbons (PAHS) are one of the most ubiquitous carcinogens in the environment, little is known regarding their potential mutagenic interactions. Risk assessment of complex PAH mixtures utilizes toxic equivalency...

Onufrock, Amy Mildred

2012-06-07

139

EPA (ENVIONMENTAL PROTECTION AGENCY) METHOD STUDY 20, METHOD 610--PNA'S (POLYNUCLEAR AROMATIC HYDROCARBONS)  

EPA Science Inventory

Sixteen laboratories participated in an interlaboratory study conducted to provide precision and accuracy statements for the proposed EPA Method 610 for 16 selected polynuclear aromatic hydrocarbons(PNA's) which may be present in municipal and industrial aqueous discharges. Metho...

140

Physico-Chemical Speciation and Ocean Fluxes of Polycyclic Aromatic Hydrocarbons.  

National Technical Information Service (NTIS)

Partitioning of ecotoxicologically significant polycyclic aromatic hydrocarbons (PAHs) to non-aqueous, particularly colloidal and soot, phases results in a decrease in their, directly bioavailable, dissolved fractions. Functionally distinguishing colloida...

O. Gustafsson

1997-01-01

141

DIGESTIVE BIOAVAILABILITY TO A DEPOSIT FEDDER (ARENICOLA MARINA) OF POLYCYCLIC AROMATIC HYDROCARBONS ASSOCIATED WITH ANTHRPOGENIC PARTICLES  

EPA Science Inventory

Marine sediments around urban areas serve as catch basins for anthropogenic particles containing polycyclic aromatic hydrocarbons (PAHs). Using incubations with gut fluids extracted from a deposit-feeding polychaete (Arenicola marina), we determined the digestive bioavailability ...

142

Public Health Impacts of Secondary Particulate Formation from Aromatic Hydrocarbons in Gasoline  

EPA Science Inventory

Background: Aromatic hydrocarbons emitted from gasoline-powered vehicles contribute to the formation of secondary organic aerosol (SOA), which increases the atmospheric mass concentration of fine particles (PM2.5). Here we estimate the public health burden associated w...

143

Magnetic Beads-based Bioelectrochemical Immunoassay of Polycyclic Aromatic Hydrocarbons  

SciTech Connect

A simple, rapid, and sensitive bioelectrochemical immunoassay method based on magnetic beads (MBs) has been developed to detect polycyclic aromatic hydrocarbons (PAHs). The principle of this bioassay is based on a direct competitive enzyme-linked immunosorbent assay using PAH-antibody-coated MBs and horseradish peroxidase (HRP)-labeled PAH (HRP-PAH). A magnetic process platform was used to mix and shake the samples during the immunoreactions and to separate free and unbound reagents after the liquid-phase competitive immunoreaction among PAH-antibody-coated MBs, PAH analyte, and HRP-PAH. After a complete immunoassay, the HRP tracers attached to MBs were transferred to a substrate solution containing 3, 3´, 5, 5´- tetramethylbenzidine (TMB) and hydrogen peroxide (H2O2) for electrochemical detection. The voltammetric characteristics of the substrate were investigated, and the reduction peak current of TMB was used to quantify the concentration of PAH. The different parameters, including the amount of HRP-PAH conjugates, the enzyme catalytic reaction time, and the pH of the supporting electrolyte that governs the analytical performance of the immunoassay have been studied in detail and optimized. The detection limit of 50 pg mL-1 was obtained under optimum experimental conditions. The performance of this bioelectrochemical magnetic immunoassay was successfully evaluated with tap water spiked with PAHs, indicating that this convenient and sensitive technique offers great promise for decentralized environmental applications.

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

2007-07-01

144

Infrared Spectroscopy of Matrix-Isolated Polycyclic Aromatic Hydrocarbon Cations  

NASA Technical Reports Server (NTRS)

Gaseous, ionized polycyclic aromatic hydrocarbons (PAHs) are thought to be responsible for a very common family of interstellar infrared emission bands. Here the near- and mid-infrared spectra of the cations of the five most thermodynamically favored PAHs up to coronene: phenanthrene, pyrene, benzo(e)pyrene, benzo-(ghi)perylene, and coronene, are presented to test this hypothesis. For those molecules that have been studied previously (pyrene, pyrene-d(sub 10), and coronene), band positions and relative intensities are in agreement. In all of these cases we report additional features. Absolute integrated absorbance values are given for the phenanthrene, perdeuteriophenanthrene, pyrene, benzo(ghi]perylene, and coronene cations. With the exception of coronene, the cation bands corresponding to the CC modes are typically 2-5 times more intense than those of the CH out-of-plane bending vibrations. For the cations, the CC stretching and CH in-plane bending modes give rise to bands that are an order of magnitude stronger than those of the neutral species, and the CH out-of-plane bends produce bands that are 5-20 times weaker than those of the neutral species. This behavior is similar to that found in most other PAH cations studied to date. The astronomical implications of these PAH cation spectra are also discussed.

Hudgins, D. M.; Allamandola, L. J.

1995-01-01

145

Polycyclic aromatic hydrocarbons and fatal ischemic heart disease  

SciTech Connect

Several toxicologic and epidemiologic studies have produced evidence that occupational exposure to polycyclic aromatic hydrocarbons (PAH) is a risk factor for ischemic heart disease (IHD). However, a clear exposure-response relation has not been demonstrated. We studied a relation between exposure to PAH and mortality from IHD (418 cases) in a cohort of 12,367 male asphalt workers from Denmark, Finland, France, Germany, Israel, The Netherlands and Norway. Exposures to benzo(a)pyrene were assessed quantitatively using measurement-driven exposure models. Exposure to coal tar was assessed in a semiquantitative manner on the basis of information supplied by company representatives. We carried out sensitivity analyses to assess potential confounding by tobacco smoking. Both cumulative and average exposure indices for benzo(a)pyrene were positively associated with mortality from IHD. The highest relative risk for fatal IHD was observed for average benzo(a)pyrene exposures of 273 ng/m{sup 3} or higher, for which the relative risk was 1.64(95% confidence interval = 1.13-2.38). Similar results were obtained for coal tar exposure. Sensitivity analysis indicated that even in a realistic scenario of confounding by smoking, we would observe approximately 20% to 40% excess risk in IHD in the highest PAH-exposure categories. Our results lend support to the hypothesis that occupational PAH exposure causes fatal IHD and demonstrate a consistent exposure-response relation for this association.

Burstyn, I.; Kromhout, H.; Partanen, T.; Svane, O.; Langard, S.; Ahrens, W.; Kauppinen, T.; Stucker, I.; Shaham, J.; Heederik, D.; Ferro, G.; Heikkila, P.; Hooiveld, M.; Johansen, C.; Randem, B.G.; Boffetta, P. [International Agency for Research on Cancer, Lyon (France)

2005-11-01

146

Polycyclic Aromatic Hydrocarbons in drinking water of Tehran, Iran  

PubMed Central

Distribution and seasonal variation of sixteen priority polycyclic aromatic hydrocarbons (PAHs) were investigated in the drinking water of Tehran, the capital of Iran. Detected single and total PAHs concentrations were in the range of 2.01-38.96 and 32.45-733.10 ng/L, respectively, which were quite high compared to the values recorded in other areas of the world. The average occurrence of PAHs with high molecular weights was 79.55%; for example, chrysene occurred in 60.6% of the samples, with a maximum concentration of 438.96 ng/L. In addition, mean carcinogen to non-carcinogen PAHs ratio was 63.84. Although the concentration of benzo[a]pyrene, as an indicator of water pollution to PAHs, was lower than the guideline value proposed by World Health Organization (WHO) as well as that of Iranian National Drinking Water Standards for all of the samples, the obtained results indicated that carcinogen PAHs present in the drinking water of Tehran can cause threats to human health. PMID:24499505

2013-01-01

147

Carbonyl atmospheric reaction products of aromatic hydrocarbons in ambient air  

NASA Astrophysics Data System (ADS)

To convert gaseous carbonyls to oximes during sampling, an XAD-4 resin denuder system pre-coated with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine and followed by analysis with methane positive chemical ionization gas chromatography/mass spectrometry was used to measure carbonyls in ambient air samples in Riverside, CA. In conjunction with similar analyses of environmental chamber OH radical-initiated reactions of o- and p-xylene, 1,2,4-trimethylbenzene, ethylbenzene, 4-hydroxy-2-butanone and 1,4-butanediol, we identified benzaldehyde, o-, m- and p-tolualdehyde and acetophenone and the dicarbonyls glyoxal, methylglyoxal, biacetyl, ethylglyoxal, 1,4-butenedial, 3-hexene-2,5-dione, 3-oxo-butanal, 1,4-butanedial and malonaldehyde in the ambient air samples. As discussed, these carbonyls and dicarbonyls can be formed from the OH radical-initiated reactions of aromatic hydrocarbons and other volatile organic compounds emitted into the atmosphere, and we conclude that in situ atmospheric formation is a major source of these carbonyls in our Riverside, CA, ambient air samples.

Obermeyer, Genevieve; Aschmann, Sara M.; Atkinson, Roger; Arey, Janet

148

Polycyclic aromatic hydrocarbons in household dust near diesel transport routes.  

PubMed

A river-dredging project has been undertaken in Nantou, Taiwan. A large number of diesel vehicles carrying gravel and sand shuttle back and forth on the main roads. Ten stations along major thoroughfares were selected as the exposure sites for testing, while a small village located about 9 km from a main traffic route was selected as the control site. Levels of household dust loading at the exposure sites (60.3 mg/m(2)) were significantly higher than those at the control site (38.2 mg/m(2)). The loading (?g/m(2)) of t-PAHs (total polycyclic aromatic hydrocarbons) in the household dust at the exposure sites was significantly higher (P < 0.05) than was the case at the control site. The diagnostic ratios of PAHs showed that diesel emissions were the dominant source of PAHs at the exposure sites. The lack of a significant correlation between the concentrations of Fe and t-PAHs suggested that the t-PAHs in household dust might come from diverse sources. However, a significant correlation (P = 0.003) between the concentrations of Mo and t-PAHs implied that the most of the t-PAHs in the household dust might have resulted from diesel emissions. The lifetime cancer risks of BaP(eq) from household dust exposure were markedly higher than those resulting from inhalation exposure. PMID:21603995

Kuo, Chung-Yih; Chen, Heng-Chun; Cheng, Fang-Ching; Huang, Li-Ru; Chien, Po-Shan; Wang, Jing-Ya

2012-02-01

149

Remediation of Polycyclic Aromatic Hydrocarbons in Soil Using Cosolvent Flushing  

NASA Astrophysics Data System (ADS)

The ability of cosolvents to increase the solubility of hydrophobic organic contaminants has been well documented in the literature; however, few studies have examined its effectiveness with respect to field contaminated media. In this work, we examine the use of methanol flushing as a possible in-situ remediation technology using an aged, tar-contaminated field soil from a former manufactured gas plant containing polycyclic aromatic hydrocarbons (PAHs). For 15 PAHs, batch experiments were used to determine the change in the equilibrium partitioning coefficient with cosolvent fraction based on a log-linear cosolvency model. Column experiments were conducted to examine the removal of PAHs using methanol solutions as a function of pore volumes flushed. Experiments were conducted in a 25-cm long glass column. Effluent concentrations were determined for PAHs. Methanol concentrations in effluent samples were also determined. A numerical model with coupled flow and transport equations was used to predict effluent concentrations of methanol and PAHs. During cosolvent flushing with 95% methanol solutions, approximately 80% of the total PAH mass was removed in the first four pore volumes. The remaining mass in the column appeared to be mass transfer limited, particularly for the low molecular weight PAHs.

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

2010-12-01

150

Biodegradation of polycyclic aromatic hydrocarbons in rhizosphere soil  

SciTech Connect

Increased contaminant biodegradation in soil in the presence of plants has been demonstrated for several classes of organic compounds. Although enhanced dissipation of polycyclic aromatic hydrocarbons (PAHs) was observed previously in the rhizosphere of several plant species, the mechanism of this effect has not been assessed. A laboratory experiment was conducted to test the importance of cometabolism and the presence of common rhizosphere organic acids on the loss of PAHs (pyrene and phenanthrene) from soil. The role of cometabolism in the mineralization of pyrene was tested by observing the impact of adding phenanthrene to soil containing {sup 14}C-pyrene and observing the effects on {sup 14}CO{sub 2} generation. Adding phenanthrene apparently induced cometabolism of pyrene, particularly in the presence of organic acids. In a subsequent experiment, mineralization of pyrene to {sup 14}CO{sub 2} was significantly greater in soil from the rhizospheres of warm-season grasses, sorghum (Sorghum bicolor L.) and bermuda grass (Cynodon dactylon L.), compared to soil from alfalfa (Medicago sativa L.), which did not differ from sterilized control soil. A highly branched, fine root system appears to be more effective in enhancing biodegradation than taproots, and the presence of organic acids increases rates of PAH mineralization.

Schwab, A.P.; Banks, M.K.; Arunachalam, M. [Kansas State Univ., Manhattan, KS (United States)

1995-12-31

151

Aromatized arborane/fernane hydrocarbons as biomarkers for cordaites  

NASA Astrophysics Data System (ADS)

Previous palaeobotanical and palynological studies on coals from Euramerican Pennsylvanian (? Late Carboniferous) coal basins indicate a major change in coal-swamp floras, especially at the Westphalian Stephanian (?Kasimovian Gzhelian, according to Geological Time Scale 2004) boundary. A flora dominated by arborescent lycophytes was replaced by a vegetation dominated by marattialean tree ferns in various Euramerican coal basins. Earlier combined palynological and organic geochemical studies on Westphalian/Stephanian coals and shales from the Saar-Nahe Basin (Germany) revealed that the distribution of aromatized arborane/fernane hydrocarbons in solvent extracts reflects the increasing importance of seed plants, especially cordaites (extinct group of gymnosperms), conifers and pteridosperms. However, the biological source of the precursor molecules could not be specified. To clarify if the arborane/fernane derivatives MATH, MAPH, DAPH 1, and DAPH 2 in Westphalian/Stephanian coals can be assigned to one of the three potential source plant groups, we analyzed coals, sediments and fossil plant remains from different Euramerican locations with respect to their biomarker composition and stable carbon isotopic composition. Thereby, stable carbon isotopic ratios showed only insignificant variations between Westphalian and Stephanian samples and proved to be an unsuitable tool to describe floral changes during the Westphalian/Stephanian of the Saar-Nahe Basin. In contrast, we were able to show for the first time that MATH, MAPH, DAPH 1 and DAPH 2 are prominent constituents only in extracts of cordaitean macrofossils and can therefore be regarded as biomarkers for this group of gymnosperms.

Auras, Stefan; Wilde, Volker; Scheffler, Kay; Hoernes, Stephan; Kerp, Hans; Püttmann, Wilhelm

2006-12-01

152

Bioavailability of polycyclic aromatic hydrocarbons in the North Sea  

SciTech Connect

Semipermeable membrane devices (SPMDs) and blue mussels (Mytilus edulis) were used to determine the bioavailable fraction of polycyclic aromatic hydrocarbons (PAHs) from oil field produced water in the North Sea. The SPMDs and mussels were deployed at 5, 10, and 50 m depth; 100 and 300 m downstream the discharge point; and at a reference site 16 km away. In both SPMDs and mussels, the concentration of PAHs increased significantly toward the discharge point, with the strongest contribution from the lower molecular weight compounds (naphthalene, phenanthrene, dibenzothiophene, and their C1-C3 alkyl homologues). The relative increase in PAH concentration from the reference site to the site at 100 m was higher for mussels than for the SPMDs. The SPMDs reflect the water-soluble fraction of the PAHs, which is probably the most important route of exposure for organisms at lower trophic levels and presumably also the fraction available for uptake by a respiratory route. Residues in the mussels represent both the water-soluble and particle-bound fraction and give information about bioavailability of the PAHs for organisms at higher trophic levels. The results of this study suggest that both techniques give important information about the bioavailability of PAHs to marine organisms.

Utvik, T.I.R. (Norsk Hydro E and P Operations, Bergen (Norway). Environmental Section); Johnsen, S. (Statoil R and D Centre, Trondheim (Norway))

1999-06-15

153

Solubilization of polycyclic aromatic hydrocarbons in micellar nonionic surfactant solutions  

SciTech Connect

Experimental data are presented on the enhanced apparent solubilities of naphthalene, phenanthrene, and pyrene resulting from solubilization in aqueous solutions of four commercial, nonionic surfactants: an alkyl polyoxyethylene (POE) type, two octylphenol POE types, and a nonylphenol POE type. Apparent solubilities of the polycyclic aromatic hydrocarbon (PAH) compounds in surfactant solutions were determined by radiolabeled techniques. Solubilization of each PAH compound commenced at the surfactant critical micelle concentration and was proportional to the concentration of surfactant in micelle form. The partitioning of organic compounds between surfactant micelles and aqueous solution is characterized by a mole fraction micelle-phase/aqueous-phase partition coefficient, K{sub m}. Values of log K{sub m} for PAH compounds in surfactant solutions of this study range from 4.57 to 6.53. Log K{sub m} appears to be a linear function of log K{sub ow} for a given surfactant solution. A knowledge of partitioning in aqueous surfactant systems is a prerequisite to understanding mechanisms affecting the behavior of hydrophobic organic compounds in soil-water systems in which surfactants play a role in contaminant remediation or facilitated transport.

Edwards, D.A.; Luthy, R.G.; Liu, Zhongbao (Carnegie Mellon Univ., Pittsburgh, PA (USA))

1991-01-01

154

Secondary organic aerosol from photooxidation of polycyclic aromatic hydrocarbons.  

PubMed

Secondary organic aerosol (SOA) formation from the photooxidation of five polycyclic aromatic hydrocarbons (PAHs, naphthalene, 1- and 2-methylnaphthalene, acenaphthylene, and acenaphthene) was investigated in a 9-m(3) chamber in the presence of nitrogen oxides and the absence of seed aerosols. Aerosol size distributions and PAH decay were monitored by a scanning mobility particle sizer and a gas chromatograph with a flame ionization detector. Over a wide range of conditions, the aerosol yields for the investigated PAHs were observed to be in the range of 2-22%. The observed evolution of aerosol and PAH decay indicate that light and oxidant sources influence the time required to form aerosol and the required threshold reacted concentration of the PAHs. The SOA yields also were related to this induction period and the hydroxyl radical concentrations, particularly for smaller aerosol loadings (

Shakya, Kabindra M; Griffin, Robert J

2010-11-01

155

Bioaccessibility of polycyclic aromatic hydrocarbons: relevance to toxicity and carcinogenesis  

PubMed Central

Introduction Bioaccessibility is a growing area of research in the field of risk assessment. As polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants, they are the toxicants of focus to establish cancer risks in humans. Orally ingested PAHs also cause toxicity and even affect the pharmacokinetic behavior of some therapeutic agents. Toward this end, bioaccessibility is being used as a tool to assess the risk of PAHs via dietary exposures. Areas covered This review covers some in vitro bioaccessibility models for PAHs that have been used for the past one-and-a-half decade. This review also considers the factors that influence bioaccessibility and debates the merits and limitations of using a bioaccessibility concept for estimating risk from ingestion of PAH-contaminated soil and food. Finally, the authors discuss the implications of bioaccessibility for PAH-induced toxicity and cancers in the context of risk assessment. Expert opinion So far, much of the focus on PAH bioaccessibility is centered on soil as a preferential matrix. However, ingestion of PAHs through diet far exceeds the amount accidentally ingested through soil. Therefore, bioaccessibility could be exploited as a tool to assess the relative risk of various dietary ingredients tainted with PAHs. While bioaccessibility is a promising approach for assessing PAH risk arising from various types of contaminated soils, none of the models proposed appears to be valid. Bioaccessibility values, derived from in vitro studies, still require validation from in vivo studies. PMID:23898780

Harris, Kelly L; Banks, Leah D; Mantey, Jane A; Huderson, Ashley C; Ramesh, Aramandla

2014-01-01

156

Cardiac Autonomic Dysfunction from Occupational Exposure to Polycyclic Aromatic Hydrocarbons  

PubMed Central

Objectives Polycyclic aromatic hydrocarbons (PAHs) exposures have been associated with cardiopulmonary mortality and cardiovascular events. This study investigated the association between a biological marker of PAHs exposure, assessed by urinary 1-hydroxypyrene (1-OHP), and heart rate variability (HRV) in an occupational cohort of boilermakers. Methods Continuous 24-hour monitoring of the ambulatory electrocardiogram (ECG) and pre and post shift urinary 1-OHP were repeated over extended periods of the work week. Mixed effects models were fit for the 5-minute standard deviation of normal-to-normal intervals (SDNN) in relation to urinary 1-OHP levels pre and post workshift on the day they wore the monitor, controlling for potential confounders. Results We found a significant decrease in 5-min SDNN during work of ?13.6% (95% confidence interval, ?17.2% to ?9.8%) for every standard deviation (0.53 microgram/gram [?g/g] creatinine) increase in the next-morning pre-shift 1-OHP levels. The magnitude of reduction in 5-min SDNN were largest during the late night period after work and increased with every standard deviation (0.46 ?g/g creatinine) increase in post-shift 1-OHP levels. Conclusion This is the first report providing evidence that occupational exposure to PAHs is associated with altered cardiac autonomic function. Acute exposure to PAHs may be an important predictor of cardiovascular disease risk in the work environment. PMID:21172795

Lee, Mi-Sun; Magari, Shannon; Christiani, David C.

2013-01-01

157

Engineered Antibodies for Monitoring of Polynuclear Aromatic Hydrocarbons  

SciTech Connect

Polynuclear aromatic hydrocarbons (PAHs) are a large class of structurally similar pollutants. Rapid, inexpensive, and high-throughput methods to identify and monitor PAHs are needed in several DOE focus areas, including human and ecosystem health effects, risk and exposure assessment, decontamination and decommissioning, and remediation. DOE has sponsored and participated in several demonstration projects in which commercial immunoassay kits proved useful and cost-effective for detection of PAHs and other pollutants. The emerging generation of sensors and residue recovery methods will require panels of antibodies with relatively subtle differences in cross-reactivity. This project is based on the premise that genetic engineering should be much more successful than conventional polyclonal and monoclonal antibody methods for developing these antibody panels. One objective of this project has been to define the structural basis and mechanisms by which antibodies bind and cross-react with various PAHs. A second objective has been to use this information to produce recombinant antibodies with improved performance in analytical procedures that DOE can use. A third objective has been development of PAH residue recovery and cleanup methods that will be compatible with immunoassays, and make instrumental analysis faster, more accurate, and less expensive.

Karu; Alexander E.; Roberts, Victoria A.; Li, Qing X.

2000-03-06

158

Stochastic atomistic simulation of polycyclic aromatic hydrocarbon growth in combustion.  

PubMed

Nanoparticles formed in gas phase environments, such as combustion, have an important impact on society both as engineering components and hazardous pollutants. A new software package, the Stochastic Nanoparticle Simulator (SNAPS) was developed, applying a stochastic chemical kinetics methodology, to computationally investigate the growth of nanoparticle precursors through trajectories of chemical reactions. SNAPS was applied to characterize the growth of polycyclic aromatic hydrocarbons (PAHs), important precursors of carbonaceous nanoparticles and soot, in a premixed laminar benzene flame, using a concurrently developed PAH growth chemical reaction mechanism, as well as an existing benzene oxidation mechanism. Simulations of PAH ensembles successfully predicted existing experimentally measured data and provided novel insight into chemical composition and reaction pathways. The most commonly observed PAH isomers in simulations showed the importance of 5-membered rings, which contrasts with traditionally assumed compositions involving primarily pericondensed 6-membered rings. In addition, the chemical growth of PAHs involved complex sequences of highly reversible reactions, rather than relatively direct routes of additions and ring closures. Furthermore, the most common reactions involved 5-membered rings, suggesting their importance to PAH growth. The framework developed in this work will facilitate future investigation of particle inception and soot formation and will benefit engineering of novel combustion technologies to mitigate harmful emissions. PMID:24647536

Lai, Jason Y W; Elvati, Paolo; Violi, Angela

2014-05-01

159

Molecular Spectroscopy in Astrophysics: The Case of Polycyclic Aromatic Hydrocarbons  

NASA Technical Reports Server (NTRS)

The role of molecular spectroscopy in astrophysics and astrochemistry is discussed in the context of the study of large, complex, carbon-bearing molecules, namely, Polycyclic Aromatic Hydrocarbons or PAHs. These molecular species are now thought to be widespread in the interstellar medium in their neutral and ionized forms. Identifying the carriers responsible for unidentified interstellar spectral bands will allow to derive important information on cosmic elemental abundances as well as information on the physical conditions (density, temperature) reigning in specific interstellar environments. These, in turn, are key elements for a correct understanding of the energetic mechanisms that govern the origin and the evolution of the interstellar medium. A multidisciplinary approach - combining astronomical observations with laboratory simulations and theoretical modeling - is required to address these complex issues. Laboratory spectra of several PAHs, isolated at low temperature in inert gas matrices or seeded in a supersonic jet expansion, are discussed here and compared to the astronomical spectra of reddened, early type, stars. The electronic spectroscopy of PAHs in the ultraviolet, visible, and near-infrared domains is reviewed and an assessment of the potential contribution of PAHs to the interstellar extinction in the ultraviolet and in the visible is discussed.

Salama, Farid; DeVincent, Donald L. (Technical Monitor)

2000-01-01

160

Polycyclic Aromatic Hydrocarbon Ionization Energy Lowering in Water Ices  

NASA Technical Reports Server (NTRS)

In studying various interstellar and solar system ice analogs, we have recently found that upon vacuum ultraviolet photolysis, polycyclic aromatic hydrocarbons (PAHs) frozen in water ice at low temperatures are easily ionized and indefinitely stabilized as trapped ions (Gudipati; Gudipati & Allamandola). Here we report the first experimental study that shows that PAH ionization energy is significantly lowered in PAH/H2O ices, in agreement with recent theoretical work (Woon & Park). The ionization energy (IE) of the PAH studied here, quaterrylene (C40H20, IE = 6.11 eV), is lowered by up to 2.11 eV in water ice. PAH ionization energy reduction in low-temperature water ice substantially expands the astronomical regions in which trapped ions and electrons may be important. This reduction in ionization energy should also hold for other types of trapped species in waterrich interstellar, circumstellar, and solar system ices. Subject headings: ISM: clouds - methods: laboratory - molecular processes - radiation mechanisms: nonthermal -ultraviolet: ISM - ultraviolet: solar system

Gudipati, Murthy S.; Allamandola, Louis J.

2004-01-01

161

Enhancement of polycyclic aromatic hydrocarbon biodegradation in the rhizosphere  

SciTech Connect

Polycyclic aromatic hydrocarbons (PAHs) are a class of potentially hazardous chemicals that exhibit toxic, mutagenic or carcinogenic properties. Microbial degradation is the major route through which PAHs are removed from contaminated environments although other mechanisms such as volatilization, leaching and photodegradation may also be effective. The rhizosphere contains a diversity of microorganisms that contribute to plant health and soil homeostasis. Recent studies indicate that microorganisms in the rhizosphere can degrade toxicants of concern to human health and the environment. The increased density and diversity of rhizosphere microflora may be an important factor for enhanced microbial degradation of PAHs. The objective of this study is to evaluate degradation of a number of different PAHs in rhizosphere and non-rhizosphere soil. It has been shown that the biodegradation rates of PAHs increase as the number of PAH rings decrease, but there is little information about the biodegradation in rhizosphere soil. The study will provide results from a microcosm experiment designed to evaluate degradation of PAHs in rhizosphere and non-rhizosphere. Also, kinetic models will be developed to represent data collected.

Kim, S.C.; Banks, M.K.; Schwab, A.P. [Kansas State Univ., Manhattan, KS (United States)

1994-12-31

162

Cyclodextrin-modified solvent extraction for polynuclear aromatic hydrocarbons  

SciTech Connect

The extraction efficiencies of several polynuclear aromatic hydrocarbons (PAHs) between isopropyl ether/water and between isopropyl ether:1-butanol (1:4)/water are measured in the presence of an aqueous ..gamma..-cyclodextrin (CDx) modifier at room temperature. The distribution of certain PAHs into the aqueous phase is increased by the presence of 10/sup -2/ M ..gamma..-CDx. For compounds such as perylene and coronene, which show the most marked effects, the extraction efficiencies into the aqueous phase from pure isopropyl ether are 95.1% and 93.7%, respectively, when the CDx modifier is used. In the mixed solvent system with 1-butanol, these values are 63.4% and 98.1%, respectively. In both systems, the increased distribution into water is based in part on the size relationship between the PAH and the CDx cavity. In the case of relatively small molecules like anthracene, little or no extraction is observed in the presence of the CDx modifier. This type of extraction system may be useful for selective extraction of large PAHs from mixtures. Extraction results for a variety of PAHs are presented and discussed.

Blyshak, L.A.; Rossi, T.M.; Patonay, G.; Warner, I.M.

1988-10-01

163

Atmospheric transport and outflow of polycyclic aromatic hydrocarbons from China.  

PubMed

A potential receptor influence function (PRIF) model, based on air mass forward trajectory calculations, was applied to simulate the atmospheric transport and outflow of polycyclic aromatic hydrocarbons (PAHs) emitted from China. With a 10 day atmospheric transport time, most neighboring countries and regions, as well as remote regions, were influenced by PAH emissions from China. Of the total annual PAH emission of 114 Gg, 92.7% remained within the boundary of mainland China. The geographic distribution of PRIFs within China was similar to the geographic distribution of the source regions, with high values in the North China Plain, Sichuan Basin, Shanxi, and Guizhou province. The Tarim basin and Sichuan basin had unfavorable meteorological conditions for PAH outflow. Of the PAH outflow from China (8092 tons or 7.1% of the total annual PAH emission), approximately 69.9% (5655 tons) reached no further than the offshore environment of mainland China and the South China Sea. Approximate 227, 71, 746, and 131 tons PAHs reached North Korea, South Korea, Russia-Mongolia region, and Japan, respectively, 2-4 days after the emission. Only 1.4 tons PAHs reached North America after more than 9 days. Interannual variation in the eastward PAH outflow was positively correlated to cold episodes of El Niño/Southern Oscillation. However, trans-Pacific atmospheric transport of PAHs from China was correlated to Pacific North America index (PNA) which is associated with the strength and position of westerly winds. PMID:18754369

Lang, Chang; Tao, Shu; Liu, Wenxin; Zhang, Yanxu; Simonich, Staci

2008-07-15

164

Superconductivity in an Alkali Doped Polycyclic Aromatic Hydrocarbon, Picene  

NASA Astrophysics Data System (ADS)

The effect of carrier doping into polycyclic aromatic hydrocarbons, including perylene and pentacene, has been extensively studied.[1] As a result of halogen or alkali metal doping, a drastic increase in electrical conductivity was observed. However, superconductivity has not been reported except the one by Sch"on et al.[2] Recently, Kubozono reported that one of them, i.e. picene (C22H14) showed superconductivity at 20 K by doping with potassium.[3] We anticipate that it will lead to surprising findings of hidden organic molecular superconductors. In this presentation, we will report on the characterization of superconducting properties of alkali doped picene. Instead of ordinary vapor phase alkali metal doping, we employ thermal decomposition of alkali azides, i.e. AN3 where A = K, Rb. We followed the doping procedure of thermal decomposition applied to fullerene C60.[4] A systematic variation of the superconducting transition temperature and fraction are studied as a function of alkali metal composition. [1] H. Akamatu, H. Inokuchi, and Y. Matsunaga, Nature 173 (1954) 168. [2] J. H. Sch"on, Ch. Kloc & B. Batlogg, Nature 406 (2000) 702; retraction, Nature 422 (2003) 93. [3] R. Mitsuhashi, Y. Kubozono et al.: private communication. [4] M. Tokumoto, et al. , J. Phys. Chem. Solids, 54 (1993) 1667.

Tokumoto, Madoka; Shimizu, Fumihiko; Hata, Yoshiaki; Sawai, Shinya; Han, Jing; Inoue, Katsuya

2010-03-01

165

Some carcinogenic polycyclic aromatic hydrocarbons by photoacoustic spectroscopy  

NASA Astrophysics Data System (ADS)

Polycyclic aromatic hydrocarbons (PAHs) have attracted spectroscopists, astrophysicts and environmentalist because of their importance in our day to day life. It is well known that epoxides are produced during the metabolism of PAHs and have the requisite chemical reactivity to qualify them for the role as an ultimate carcinogenic form of PAHs. Several carcinogenic PAHs such as 3.4-benzopyrene, 1.2,3.4-dibenzopyrene, 3.4,9.10- dibenzopyrene etc. are found to be present in tobacco smoke and among air pollutants. Although PAH molecules are being studied for last several years by using conventional spectroscopy but no systematic attempt has been made to study non-radiative transitions. In our laboratory, we have studied many PAH molecules by a non-destructive technique with unique capability and sensitivity, known as Photoacoustic (PA) spectroscopy. PA spectroscopy is an analytical and research tool to get information about non-radiative transitions and singlet-triplet electronic transitions, where the conventional spectroscopic technique fails. The study of electronic transitions of some carcinogenic molecules are reported using PA and optical absorption spectra in boric acid glass in the region 250 - 400 nm. The electronic transitions of these molecules observed experimentally, have been interpreted using the optimized geometries and CNDO/S-CI method. A good agreement is found between the experimental and calculated results. Assignments of observed electronic transitions are made on the basis of singlet-triplet electronic transitions. Vibrations attached to these electronic transitions are attributed to the ground state vibrational modes.

Garg, R. K.; Kumar, Pardeep; Ram, R. S.; Zaidi, Zahid H.

1999-12-01

166

Coupled oxidation of aromatic hydrocarbons by horseradish peroxidase and hydrogen peroxide  

Microsoft Academic Search

The oxidation capability of horseradish peroxidase (HRP) and hydrogen peroxide (H2O2) coupled oxidation of aromatic hydrocarbons (o-xylene-d10 and naphthalene-d8) was investigated. Batch experiments were conducted using horseradish peroxidase prepared in potassium phosphate buffer in the presence of H2O2. The oxidation of aromatic hydrocarbon was tested as a function of HRP at a fixed concentration of H2O2, and as a function

Jiasong Fang; Michael J Barcelona

2003-01-01

167

Characterization of the Aromatic Hydrocarbon Receptor Gene and Its Expression in Atlantic Tomcod  

Microsoft Academic Search

Cytochrome P4501A1 (CYP1A1) mRNA is not inducible in Atlantic tomcod from the Hudson River that are treated with halogenated aromatic hydrocarbons (HAHs). In contrast, CYP1A1 mRNA is inducible in Hudson River tomcod that are treated with polycyclic aromatic hydrocarbons (PAHs) and in tomcod that are collected from cleaner rivers and treated with HAHs or PAHs. We hypothesize that CYP1A1 transcription

Nirmal K. Roy; Isaac Wirgin

1997-01-01

168

Aromatic hydrocarbons of the tar from the thermal decomposition of peat  

Microsoft Academic Search

An investigation of the aromatic hydrocarbons of the tar obtained in the low temperature carbonization of high-moor pine-cottongrass peat and a distillate of it (150-350°C) has been carried out by chemical and physicochemical methods. It has been established that the initial tar contained 22.2%, and its distillate 10.2%, of aromatic hydrocarbons. In both cases, these consisted of alklyated monocyclic compounds

S. V. Zubko; S. V. Drozdovskaya; E. A. Yurkevich

1984-01-01

169

Sequential accelerated solvent extraction of polycyclic aromatic hydrocarbons with different solvents: performance and implication.  

PubMed

Sixteen USEPA priority polycyclic aromatic hydrocarbons (PAHs) extracted by Soxhlet extraction (S-PAHs) with dichloromethane and routine accelerated solvent extraction (A-PAHs) with 1:1 toluene/methanol, respectively, were investigated in 24 soil samples from two cities in the center of the Pearl River Delta, South China. Polycyclic aromatic hydrocarbons, methylphenanthrene and perylene, in two soils, two sediments, and an immature oil shale were also sequentially extracted by accelerated solvent extraction (ASE) with each of four different organic solvents for three times. The A-PAHs' concentrations are 2.41 times the S-PAHs' concentrations. For sequential three ASEs, PAHs in the first extract account for 56 to 67% of their total concentrations in the sequential three extractions and toluene displays the best extraction performance among the four solvents. Diagnostic ratios of PAHs in Soxhlet extraction, routine ASE, and sequential ASE with each solvent for a given sample are very similar, suggesting their identical petrogenic and pyrogenic sources in the soils and sediments. But the PAH ratios for the shale have an obvious petrogenic origin. The perylene/5-ring PAH ratios indicate a diagenetic source, especially in the shale and sediments. The correlation analysis shows that A-PAHs/S-PAHs is better associated with the contents of total organic carbon (TOC) than those of black carbon (BC). The above results indicate the significant petrogenic origin of PAHs and the important effect of organic matter on their extraction and distribution in the investigated field soils/sediments. PMID:21284305

Ma, Xiaoxuan; Ran, Yong; Gong, Jian; Chen, Diyun

2010-01-01

170

Polycyclic aromatic hydrocarbon exhaust emissions from different reformulated diesel fuels and engine operating conditions  

NASA Astrophysics Data System (ADS)

The study of light-duty diesel engine exhaust emissions is important due to their impact on atmospheric chemistry and air pollution. In this study, both the gas and the particulate phase of fuel exhaust were analyzed to investigate the effects of diesel reformulation and engine operating parameters. The research was focused on polycyclic aromatic hydrocarbon (PAH) compounds on particulate phase due to their high toxicity. These were analyzed using a gas chromatography-mass spectrometry (GC-MS) methodology. Although PAH profiles changed for diesel fuels with low-sulfur content and different percentages of aromatic hydrocarbons (5-25%), no significant differences for total PAH concentrations were detected. However, rape oil methyl ester biodiesel showed a greater number of PAH compounds, but in lower concentrations (close to 50%) than the reformulated diesel fuels. In addition, four engine operating conditions were evaluated, and the results showed that, during cold start, higher concentrations were observed for high molecular weight PAHs than during idling cycle and that the acceleration cycles provided higher concentrations than the steady-state conditions. Correlations between particulate PAHs and gas phase products were also observed. The emission of PAH compounds from the incomplete combustion of diesel fuel depended greatly on the source of the fuel and the driving patterns.

Borrás, Esther; Tortajada-Genaro, Luis A.; Vázquez, Monica; Zielinska, Barbara

2009-12-01

171

Method of upgrading oils containing hydroxyaromatic hydrocarbon compounds to highly aromatic gasoline  

DOEpatents

The present invention is a multi-stepped method of converting an oil which is produced by various biomass and coal conversion processes and contains primarily single and multiple ring hydroxyaromatic hydrocarbon compounds to highly aromatic gasoline. The single and multiple ring hydroxyaromatic hydrocarbon compounds in a raw oil material are first deoxygenated to produce a deoxygenated oil material containing single and multiple ring aromatic compounds. Then, water is removed from the deoxygenated oil material. The next step is distillation to remove the single ring aromatic compounds as gasoline. In the third step, the multiple ring aromatics remaining in the deoxygenated oil material are cracked in the presence of hydrogen to produce a cracked oil material containing single ring aromatic compounds. Finally, the cracked oil material is then distilled to remove the single ring aromatics as gasoline.

Baker, E.G.; Elliott, D.C.

1993-01-19

172

Atmospheric concentrations of saturated and aromatic hydrocarbons around a Greek oil refinery  

Microsoft Academic Search

Petroleum refineries are large industrial installations that are responsible for the emission of several pollutants into the atmosphere. Hydrocarbons are among the most important air pollutants that are emitted by petroleum refineries, since they are involved in almost every refinery process. The ambient air concentrations of many saturated and aromatic hydrocarbons were measured in several sites around an oil refinery,

P. D. Kalabokas; J. Hatzianestis; J. G. Bartzis; P. Papagiannakopoulos

2001-01-01

173

Natural background and anthropogenic inputs of polycyclic aromatic hydrocarbons (PAH) in sediments of South-Western Barents Sea.  

PubMed

Polycyclic aromatic hydrocarbons (PAH) were measured in sediment cores from 13 locations in South-Western Barents Sea as part of a detailed study of the Norwegian seabed under the MAREANO program. The generally low PAH levels found, an average around 200 ng g(-1) dry weight for sum PAH, indicate low inputs of petroleum hydrocarbons to the marine environment in the area. Differences in PAH composition and various PAH ratios indicate a natural, mostly petrogenic origin of PAH in sediments from the open sea locations, while the fjord locations show higher pyrogenic PAH contents with an increase towards upper sediment layers, indicating low inputs from human activities. Petrogenic PAH levels increase in deeper sediments at open sea locations, also when normalised to total organic carbon (TOC) contents, suggesting natural leakages of oil-related hydrocarbons in the area. PMID:19643470

Boitsov, Stepan; Jensen, H K B; Klungsøyr, Jarle

2009-12-01

174

Vapor pressures and enthalpies of sublimation of polycyclic aromatic hydrocarbons and their derivatives  

SciTech Connect

The vapor pressures of a series of polycyclic aromatic hydrocarbons (PAH) and heteroatom-containing PAH have been measured using the Knudsen effusion technique. Aromatic hydrocarbons examined included anthracene, phenanthrene, pyrene, 2,3-benzofluorene, naphthacene, perylene, pentacene, and coronene. Heteroatomic aromatic species examined included phenanthridine, perinaphthenone, 3-hydroxy-1-phenalen-1-one, benz[g]isoquinoline-5,10-dione, 1,2-benzodiphenylene sulfide, 1-hydroxypyrene, and 6,11-dihydroxy-5,12-naphthacenedione. The measurements were all made in the solid sublimation regime, and enthalpies of sublimation were calculated from the Clausius-Clapeyron equation.

Oja, V.; Suuberg, E.M. [Brown Univ., Providence, RI (United States). Div. of Engineering] [Brown Univ., Providence, RI (United States). Div. of Engineering

1998-05-01

175

UV irradiation of polycyclic aromatic hydrocarbons in ices: production of alcohols, quinones, and ethers  

NASA Technical Reports Server (NTRS)

Polycyclic aromatic hydrocarbons (PAHs) in water ice were exposed to ultraviolet (UV) radiation under astrophysical conditions, and the products were analyzed by infrared spectroscopy and mass spectrometry. Peripheral carbon atoms were oxidized, producing aromatic alcohols, ketones, and ethers, and reduced, producing partially hydrogenated aromatic hydrocarbons, molecules that account for the interstellar 3.4-micrometer emission feature. These classes of compounds are all present in carbonaceous meteorites. Hydrogen and deuterium atoms exchange readily between the PAHs and the ice, which may explain the deuterium enrichments found in certain meteoritic molecules. This work has important implications for extraterrestrial organics in biogenesis.

Bernstein, M. P.; Sandford, S. A.; Allamandola, L. J.; Gillette, J. S.; Clemett, S. J.; Zare, R. N.

1999-01-01

176

Bacterial degradation of high molecular-weight polynuclear aromatic hydrocarbons  

SciTech Connect

The ability of Pseudomonas paucimobilis, strain EPA 505 (a soil bacterium capable of utilizing fluoranthene as the sole source of carbon and energy for growth) to metabolize a variety of high molecular-weight polynuclear aromatic hydrocarbons (PAHs) was investigated. After 16 hours of incubation with 10 ppm of a PAH, a resting cell suspension (1 mg wet cells/ml) of P. paucimobilis grown on fluoranthene degraded 80.0, 72.9, 31.5, 33.3, 12.5, and 7.8% of pyrene, benz[a]anthracene (B[a]A), chrysene, benzo[a]pyrene (B[a]P), benzo[b]fluoranthene (B[b]F), and dibenz[a,h]anthracene (DB[a,h]A), respectively. No degradation of dibenz[a,1]pyrene was detected under these conditions. Studies with [7-{sup 14}C]B[a]P and [5,6,11,12-{sup 14}C]chrysene showed that after 48 hours of incubation, the cells degraded nearly 28 and 42% of {sup 14}C-B[a]P and {sup 14}C-chrysene to {sup 14} C0{sub 2}, respectively, suggesting that the bacterium is able to metabolize B[a]P and chrysene via ring cleavage. No evolution of {sup 14}CO{sub 2} was detected from cultures incubated with [4,5,9,10{sup 14}C]pyrene or [1,2,3,4,4a,4bU-{sup 14}C]dibenz[a,1]pyrene. The degradation of B[a]P with P. paucimobilis significantly reduced the mutagenic activity associated with the hydrocarbon. The addition of 5 ppm of B[a]A, chrysene, fluoranthene, or DB[a,h]A to the incubation medium containing 5 ppm B[a]P had no effect on the degradation of B[a]P by P. paucimobilis. The data suggest that P. paucimobilis, strain EPA 505 may be useful for remediation of PAH-contaminated sites.

Ye, D.; Siddiqi, A.; Kumar, S.; Sikka, H.C. [State Univ. of New York, Buffalo, NY (United States)

1995-12-31

177

Analysis of pyrolysis products from light hydrocarbons and kinetic modeling for growth of polycyclic aromatic hydrocarbons with detailed chemistry  

Microsoft Academic Search

Alternative chemical reaction pathways leading to polycyclic aromatic hydrocarbons (PAHs) in the pyrolysis of unsaturated light hydrocarbons were investigated to extend the previously proposed chemical kinetic model [K. Norinaga, O. Deutschmann, Ind. Eng. Chem. Res. 46 (2007) 3547–3557]. Although the previous model provided a reasonably good description of the pyrolysis behaviors observed in flow reactor experiments at 1073–1373K, the concentration

Koyo Norinaga; Olaf Deutschmann; Naomichi Saegusa; Jun-ichiro Hayashi

2009-01-01

178

Polycyclic Aromatic Hydrocarbons in Residential Dust: Sources of Variability  

PubMed Central

Background: There is interest in using residential dust to estimate human exposure to environmental contaminants. Objectives: We aimed to characterize the sources of variability for polycyclic aromatic hydrocarbons (PAHs) in residential dust and provide guidance for investigators who plan to use residential dust to assess exposure to PAHs. Methods: We collected repeat dust samples from 293 households in the Northern California Childhood Leukemia Study during two sampling rounds (from 2001 through 2007 and during 2010) using household vacuum cleaners, and measured 12 PAHs using gas chromatography–mass spectrometry. We used a random- and a mixed-effects model for each PAH to apportion observed variance into four components and to identify sources of variability. Results: Median concentrations for individual PAHs ranged from 10 to 190 ng/g of dust. For each PAH, total variance was apportioned into regional variability (1–9%), intraregional between-household variability (24–48%), within-household variability over time (41–57%), and within-sample analytical variability (2–33%). Regional differences in PAH dust levels were associated with estimated ambient air concentrations of PAH. Intraregional differences between households were associated with the residential construction date and the smoking habits of residents. For some PAHs, a decreasing time trend explained a modest fraction of the within-household variability; however, most of the within-household variability was unaccounted for by our mixed-effects models. Within-household differences between sampling rounds were largest when the interval between dust sample collections was at least 6 years in duration. Conclusions: Our findings indicate that it may be feasible to use residential dust for retrospective assessment of PAH exposures in studies of health effects. PMID:23461863

Metayer, Catherine; Petreas, Myrto; Does, Monique; Buffler, Patricia A.; Rappaport, Stephen M.

2013-01-01

179

Engineered antibodies for monitoring of polynuclear aromatic hydrocarbons  

SciTech Connect

'The long-term goal of this project is to develop antibodies and antibody-based methods for detection and recovery of polynuclear aromatic hydrocarbons (PAHs) and PAH adducts that are potential biomarkers in environmental and biological samples. The inherent cross-reactivity will be exploited by pattern recognition methods. Dr. Karu''s laboratory uses new haptens representing key PAHs to derive recombinant Fab (rFab) and single-chain Fv (scFv) antibodies from hybridoma lines and combinatorial phage display libraries. Computational models of the haptens and combining sites made by Dr. Roberts''s group are used to guide antibody engineering by mutagenesis. Dr. Li''s laboratory develops enzyme immunoassays (EIAs), sensors, and immunoaffinity methods that make use of the novel haptens and antibodies for practical analytical applications in support of DOE''s mission. This report summarizes work completed in one and one-half years of a 3-year project, with close collaboration between the three research groups. Dr. Alexander Karu''s laboratory: the authors proceeded with the two strategies described in the original proposal. Site-directed mutagenesis was used to correct differences in the rFab N-terminal amino acids that were introduced by the degenerate PCR primers used for gene amplification. The binding constants of the rFabs with the corrected sequences will be compared with those of the parent MAbs, and should be very similar. The 4D5 and 10C10 heavy and light chain sequences are being moved to the pCOMB3H phagemid vector to facilitate selection of new engineered mutants.'

Karu, A.E. [Univ. of California, Berkeley, CA (US); Roberts, V.A. [Scripps Research Inst., La Jolla, CA (US); Li, Q.X. [Univ. of Hawaii, Honolulu, HI (US)

1998-06-01

180

Human Colon Microbiota Transform Polycyclic Aromatic Hydrocarbons to Estrogenic Metabolites  

PubMed Central

Ingestion is an important exposure route for polycyclic aromatic hydrocarbons (PAHs) to enter the human body. Although the formation of hazardous PAH metabolites by human biotransformation enzymes is well documented, nothing is known about the PAH transformation potency of human intestinal microbiota. Using a gastrointestinal simulator, we show that human intestinal microbiota can also bioactivate PAHs, more in particular to estrogenic metabolites. PAH compounds are not estrogenic, and indeed, stomach and small intestine digestions of 62.5 nmol naphthalene, phenanthrene, pyrene, and benzo(a)pyrene showed no estrogenic effects in the human estrogen receptor bioassay. In contrast, colon digests of these PAH compounds displayed estrogenicity, equivalent to 0.31, 2.14, 2.70, and 1.48 nmol 17?-ethynylestradiol (EE2), respectively. Inactivating the colon microbiota eliminated these estrogenic effects. Liquid chromatography–mass spectrometry analysis confirmed the microbial PAH transformation by the detection of PAH metabolites 1-hydroxypyrene and 7-hydroxybenzo(a)pyrene in colon digests of pyrene and benzo(a)pyrene. Furthermore, we show that colon digests of a PAH-contaminated soil (simulated ingestion dose of 5 g/day) displayed estrogenic activity equivalent to 0.58 nmol EE2, whereas stomach or small intestine digests did not. Although the matrix in which PAHs are ingested may result in lower exposure concentrations in the gut, our results imply that the PAH bioactivation potency of colon microbiota is not eliminated by the presence of soil. Moreover, because PAH toxicity is also linked to estrogenicity of the compounds, the PAH bioactivation potency of colon microbiota suggests that current risk assessment may underestimate the risk from ingested PAHs. PMID:15626640

Van de Wiele, Tom; Vanhaecke, Lynn; Boeckaert, Charlotte; Peru, Kerry; Headley, John; Verstraete, Willy; Siciliano, Steven

2005-01-01

181

Polycyclic aromatic hydrocarbons and digestive tract cancers: a perspective.  

PubMed

Cancers of the colon are most common in the Western world. In majority of these cases, there is no familial history and sporadic gene damage seems to play an important role in the development of tumors in the colon. Studies have shown that environmental factors, especially diet, play an important role in susceptibility to gastrointestinal (GI) tract cancers. Consequently, environmental chemicals that contaminate food or diet during preparation become important in the development of GI cancers. Polycyclic aromatic hydrocarbons (PAHs) are one such family of ubiquitous environmental toxicants. These pollutants enter the human body through consumption of contaminated food, drinking water, inhalation of cigarette smoke, automobile exhausts, and contaminated air from occupational settings. Among these pathways, dietary intake of PAHs constitutes a major source of exposure in humans. Although many reviews and books on PAHs and their ability to cause toxicity and breast or lung cancer have been published, aspects on contribution of diet, smoking and other factors toward development of digestive tract cancers, and strategies to assess risk from exposure to PAHs have received much less attention. This review, therefore, focuses on dietary intake of PAHs in humans, animal models, and cell cultures used for GI cancer studies along with epidemiological findings. Bioavailability and biotransformation processes, which influence the disposition of PAHs in body and the underlying causative mechanisms of GI cancers, are also discussed. The existing data gaps and scope for future studies is also emphasized. This information is expected to stimulate research on mechanisms of sporadic GI cancers caused by exposure to environmental carcinogens. PMID:22107166

Diggs, Deacqunita L; Huderson, Ashley C; Harris, Kelly L; Myers, Jeremy N; Banks, Leah D; Rekhadevi, Perumalla V; Niaz, Mohammad S; Ramesh, Aramandla

2011-10-01

182

Human colon microbiota transform polycyclic aromatic hydrocarbons to estrogenic metabolites.  

PubMed

Ingestion is an important exposure route for polycyclic aromatic hydrocarbons (PAHs) to enter the human body. Although the formation of hazardous PAH metabolites by human biotransformation enzymes is well documented, nothing is known about the PAH transformation potency of human intestinal microbiota. Using a gastrointestinal simulator, we show that human intestinal microbiota can also bioactivate PAHs, more in particular to estrogenic metabolites. PAH compounds are not estrogenic, and indeed, stomach and small intestine digestions of 62.5 nmol naphthalene, phenanthrene, pyrene, and benzo(a)pyrene showed no estrogenic effects in the human estrogen receptor bioassay. In contrast, colon digests of these PAH compounds displayed estrogenicity, equivalent to 0.31, 2.14, 2.70, and 1.48 nmol 17alpha-ethynylestradiol (EE2), respectively. Inactivating the colon microbiota eliminated these estrogenic effects. Liquid chromatography-mass spectrometry analysis confirmed the microbial PAH transformation by the detection of PAH metabolites 1-hydroxypyrene and 7-hydroxybenzo(a)pyrene in colon digests of pyrene and benzo(a)pyrene. Furthermore, we show that colon digests of a PAH-contaminated soil (simulated ingestion dose of 5 g/day) displayed estrogenic activity equivalent to 0.58 nmol EE2, whereas stomach or small intestine digests did not. Although the matrix in which PAHs are ingested may result in lower exposure concentrations in the gut, our results imply that the PAH bioactivation potency of colon microbiota is not eliminated by the presence of soil. Moreover, because PAH toxicity is also linked to estrogenicity of the compounds, the PAH bioactivation potency of colon microbiota suggests that current risk assessment may underestimate the risk from ingested PAHs. PMID:15626640

Van de Wiele, Tom; Vanhaecke, Lynn; Boeckaert, Charlotte; Peru, Kerry; Headley, John; Verstraete, Willy; Siciliano, Steven

2005-01-01

183

Polycyclic aromatic hydrocarbons in surface sediments of the Jialu River.  

PubMed

The Jialu River, an important branch of the Huaihe River in China, was seriously polluted because of rapid economic growth and urbanization. In order to evaluate the potential for serious environmental consequences as a result of anthropogenic contamination, the distribution of polycyclic aromatic hydrocarbons (PAHs) has been investigated in surface sediment samples collected in connection with field surveys of 19 sites along the Jialu River. The total concentration of the 16 USEPA priority PAHs ranged from 466.0 to 2605.6 ng/g dry weight with a mean concentration of 1363.2 ng/g. Sediment samples with the highest PAH concentrations were from the upper reaches of the river, where Zhengzhou City is located; the PAH levels in the middle and lower reaches were relatively low. According to the observed molecular indices, PAHs originated largely from the high-temperature pyrolytic process. According to the numerical effect-based sediment quality guidelines (SQGs) of the United States, the levels of PAHs in the Jialu River should not exert adverse biological effects. The total benzo[a]pyrene toxicity equivalent (TEQ) values calculated for samples varied from 50.4 to 312.8 ng/g dry weight with an average of 167.4 ng/g. The relationships between PAHs and environmental factors, including chemical properties of sediments, water quality, aquatic organisms, hydrological conditions, and anthropogenic activities, are also discussed. PAHs exerted a potential negative impact on the benthos. Settlement percentage, population density and industrial GDP per capita had a significant influence on the distribution of PAHs. PMID:21451950

Fu, Jie; Sheng, Sheng; Wen, Teng; Zhang, Zhi-Ming; Wang, Qing; Hu, Qiu-Xiang; Li, Qing-Shan; An, Shu-Qing; Zhu, Hai-Liang

2011-07-01

184

Hydrogen chemisorption on polycyclic aromatic hydrocarbons via tunnelling  

NASA Astrophysics Data System (ADS)

The chemisorption of hydrogen atoms on polycyclic aromatic hydrocarbons (PAHs) is studied at low temperatures via quantum mechanical tunnelling through reaction barriers. PAHs are ubiquitous in the interstellar medium and may exist in various charge states as well as hydrogenation states. PAHs have been suggested to catalyze H2 formation in photon-dominated regions via chemisorbed hydrogen atoms. Hydrogenated PAHs are also implicated by the relative strengths of the infrared bands in protoplanetary nebulae, reflection nebulae and H II regions. The activation barrier for the chemisorption of hydrogen atoms to graphite is prohibitively high (˜5000 K) at low to moderate temperatures for this reaction to occur classically. On PAHs, however, edge sites are more flexible and can accommodate the incoming hydrogen atom more easily, resulting in a lower barrier. Combined with a further rate enhancement via tunnelling, hydrogen chemisorption on PAH edges may become feasible in various regions in the interstellar medium. We present harmonic quantum transition state theory calculations, which incorporate tunnelling, on pyrene as a model PAH system. Indeed the relatively low (˜2000 K) classical activation barriers for hydrogen atom chemisorption on edge sites combined with strong tunnelling give rise to non-negligible rates of the order of 10-16-10-18 cm3 site-1 s-1 at temperatures as low as 40 K, with a large kinetic isotope effect kH/kD? 64, characteristic for tunnelling. At this temperature, chemisorption on the core of a PAH is orders of magnitude slower, ˜10-22.5 cm3 site-1 s-1 even for the lightest H isotope. The addition of H atoms to PAH edge sites via tunnelling could be efficient enough to contribute H-PAH formation, although other processes may be more important.

Goumans, T. P. M.

2011-08-01

185

Degradation and transformation of polycyclic aromatic hydrocarbons in soil systems  

SciTech Connect

Biodegradation of fourteen polycyclic aromatic hydrocarbon (PAH) compounds in two soils was studied by measuring parent compound disappearance and volatilization emission losses of these compounds from soil samples. Degradation kinetic rates using a first-order model were calculated as half-lives. Mean degradation half-lives corrected for volatilization varied from two days for two-ring PHAs to 59 days for three-ring PHAs to more than 300 days for PHAs with more than three rings. Volatilization corrected degradation of two-and three-ring PAH compounds in soil samples poisoned by 2% HgCl/sub 2/ was small but significant (p < 0.05). No significant degradation from poisoned soil was found for the PAH compound with more than three rings. RITZE (the Enhanced Regulatory and Investigative Treatment Zone) model was used to evaluate the treatment and leaching potential of PAH compounds in soil systems. All 12 PAH compounds evaluated were significantly assimilated in the soil system and no significant leaching of these compounds to ground water was predicted. Transformation of 7,12-dimethylbenz(a)anthracene was studied in a nonacclimated sandy loam soil at low and neutral pH soil conditions. Soil extracts containing transformation products were separated into three fractions based on HPLC retention time (polarity). Highly polar transformation products of 7,12-dimethylbenz(a)anthracene demonstrated a negative mutagenic response with the Ames mutagenicity assay, strain TA-100, for both low and neutral pH soils. Moderate and low polar fractions, however, induced mutagenicity for both soil samples with mutagenic ratios similar to those of the parent compound. Mutagenic responses for the metabolites formed from low and neutral pH soil were not different. Similar microbial distributions in the two pH soils contributed to this result.

Park, K.

1987-01-01

186

THE EFFECTS OF EQUIVALENCE RATIO ON THE FORMATION OF POLYCYCLIC AROMATIC HYDROCARBONS AND SOOT IN PREMIXED ETHANE FLAMES. (R825412)  

EPA Science Inventory

Abstract The formation of polycyclic aromatic hydrocarbons (PAH) and soot has been investigated in atmospheric-pressure, laminar, ethane/oxygen/argon premixed flames as a function of mixture equivalence ratio. Mole fraction profiles of major products, trace aromatics, ...

187

Occurrence of polycyclic aromatic hydrocarbons throughout the processing stages of erva-mate (Ilex paraguariensis).  

PubMed

The presence of polycyclic aromatic hydrocarbons (PAHs) in mate (Ilex paraguariensis) is believed to be due to the degradation of mate compounds and the burning of wood during the "sapeco" (rapid drying process) and the final drying steps, which are the most important processing stages in mate production. Due to the high toxicity of these compounds, studies on their presence in mate are extremely important. The aim of this study was to evaluate PAH levels in mate throughout the processing stages of its production. The PAHs were measured in samples collected at different stages of mate processing. Total PAHs content ranged widely (443-9001 microg/kg) in the samples, with the highest PAHs levels recorded during the mate drying step. The results indicate that the processing method currently used in mate production may lead to an increase in PAHs levels in the final product. PMID:20349373

Vieira, Manoela Alano; Maraschin, Marcelo; Rovaris, Angela Angeloni; Amboni, Renata Dias de Mello Castanho; Pagliosa, Cristiane Manfé; Xavier, José Júnior Mendonca; Amante, Edna Regina

2010-06-01

188

Polycyclic aromatic hydrocarbon (PAH) in four fish species from different trophic levels in the Persian Gulf.  

PubMed

Concentration of ten polycyclic aromatic hydrocarbon (PAH) compounds were determined in liver of four fish species from different trophic levels (Aurigequula fasciata, omnivore; Alepes djedaba, carnivore; Liza abu and Sardinella albella, phytoplanktivores). In all the species, similar distributions were observed in which pyrene predominated and followed by naphthalene and acenaphthylene. L. abu accumulated the highest concentration of ?PAH, followed by S. albella, A. fasciata, and A. djedaba. No correlation between PAH content in fish liver and fish size has been found at the level of individual compounds, except for benzo[a]pyrene (p?

Rahmanpour, Shirin; Farzaneh Ghorghani, Nasrin; Lotfi Ashtiyani, Seyede Masoumeh

2014-11-01

189

Nitrated polycyclic aromatic hydrocarbons and azaarenes induce cytochrome P4501A in a fish hepatoma cell line  

Microsoft Academic Search

Nitrated polycyclic aromatic hydrocarbons (NPAH) and N-heterocyclic aromatic hydrocarbons (azaarenes) are as ubiquitous in the environment as their parent polycyclic aromatic hydrocarbon (PAH) compounds, although concentrations are commonly lower. Some of the NPAH and azaarenes are carcinogenic in mammals. Little is known, however, about their carcinogenicity and cytochrome P4501A (CYP1A) induction potency in fish. In this study, CYP1A induction potencies,

K. Fent; D. K. J. Jung

2000-01-01

190

Distribution of aliphatic hydrocarbons, polycyclic aromatic hydrocarbons and organochlorinated pollutants in deep-sea sediments of the Southern Cretan margin, Eastern Mediterranean Sea: a baseline assessment.  

PubMed

Deep sediments from the southern Cretan margin were analyzed to establish baseline levels for various types of organic pollutants before the anticipated intensification of anthropogenic activities. The total concentration of aliphatic hydrocarbons (?AH:326-3758ngg(-1), dry weight) was similar to those reported for deep sediments of the western Mediterranean Sea, while considerably lower levels were measured for polycyclic aromatic hydrocarbons (?PAH:9-60ngg(-1)). Source-diagnostic ratios suggested that the aliphatic hydrocarbons in sediments were mainly of terrestrial biogenic origin, while polycyclic aromatic hydrocarbons stemmed from the deposition of long-range transported combustion aerosols. Among the organochlorinated compounds analyzed, ?-hexachlorocyclohexane (?-HCH:222-7052pgg(-1)), 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (p,p'-DDT:37-2236pgg(-1)) and polychlorinated biphenyls (?PCB:38-1182pgg(-1)) showed the highest abundance in sediments. The presence of HCHs and PCBs was attributed to historical inputs that have undergone extensive weathering, whereas an ongoing fresh input was suggested for p,p'-DDT. Multiple linear regression analysis revealed that the levels of the various pollutants in sediments were controlled by different factors, but with organic carbon content playing a prominent role in most cases. PMID:24447909

Mandalakis, Manolis; Polymenakou, Paraskevi N; Tselepides, Anastasios; Lampadariou, Nikolaos

2014-07-01

191

Microbial Community Structure by Fatty Acid Analysis during Polycyclic Aromatic Hydrocarbon Degradation in River Sediment Augmented with Pleurotus ostreatus.  

E-print Network

??This research was conducted to determine changes in the microbial community in contaminated sediment during fungal remediation of polycyclic aromatic hydrocarbon (PAH) contaminated Mahoning River… (more)

Sajja, Sarala Kumari

2008-01-01

192

Trace level determination of polycyclic aromatic hydrocarbons in river water with automated pretreatment HPLC.  

PubMed

A novel on-line pretreatment pump-injection HPLC system for polycyclic aromatic hydrocarbons is proposed. We report novel pump-injection HPLC-based on-line SPE with a specially designed pretreatment column for the determination of trace amounts of chemical substances in surface water. Polycyclic aromatic hydrocarbons are well known for strong carcinogenicity and thus a severe concentration control is required for drinking water and/or river water, which is the main resource of tap water. We found it possible to detect ng/L levels of polycyclic aromatic hydrocarbons by using pump-injection column switching HPLC with fluorescence detection. To avoid the phenomenon, in which polycyclic aromatic hydrocarbons can be often adsorbed on the surface of flow lines of HPLC by their highly hydrophobicity especially resin-made parts in sample delivery pump, we employed "autodilution" device that provides reliable recovery and repeatability. Additionally, real water samples were collected and then the spiked polycyclic aromatic hydrocarbons were determined at ng/L levels. PMID:23427143

Watabe, Yoshiyuki; Kubo, Takuya; Tanigawa, Tetsuya; Hayakawa, Yoshihiro; Otsuka, Koji; Hosoya, Ken

2013-03-01

193

Intermediates in the Formation of Aromatics in Hydrocarbon Combustion  

NASA Technical Reports Server (NTRS)

The formation of the first benzene ring is believed to be the rate limiting step in soot formation. Two different mechanisms have been proposed for formation of cyclic C6 species. The first involves the reaction of two acetylenes to give CH2CHCCH (vinyl acetylene), the loss of a H to give CHCHCCH (n-C41-13) or CH2CCCH (iso-C4H3), and addition of another acetylene to n-C4H3, followed by ring closure to give phenyl radical. Miller and Melius argue that only n-C4H3 leads to phenyl radical and since iso-C4H3 is more stable than n-C4H3 this mechanism is unlikely. An alternative mechanism proposed by them is formation of benzene from the dimerization of two CH2CCH (propargyl) radicals (formed by the reaction of singlet methylene with C2H2). We report reaction pathways and accurate energetics (from CASSCF/internally contracted CI calculations) for the reactions of CH(pi-2) and CH2-1 with acetylene, the reaction of vinylidene with acetylene, and the reaction of n-C4H3 and iso-C4H3 with acetylene. These calculations identify two new reactive intermediates CHCHCH ( a A"-2 ground state in Cs symmetry; spin coupling is a doublet from three singly occupied orbitals) and CHCCH (B-3 ground state in C2 symmetry) from the reaction of CH with acetylene. These species dimerize with no barrier to form benzene and para-benzyne, respectively. CHCCH is proposed as a reactive intermediate which can add to benzene to give higher polynuclear aromatic hydrocarbons or fullerenes. The addition of a C3H2 unit releases two C-C bond energies and thus the resulting addition product contains sufficient energy to break several CH bonds leading to a reduction in the H to C ratio as the cluster size increases. It is found that iso-C4H3 adds to acetylene to initially give a fulvene radical but that this species rearranges to phenyl radical. Thus, the reaction of acetylene with iso-C4H3 does lead to phenyl radical and the cyclization pathway may also contribute to formation of the initial benzene ring.

Walch, Stephen P.; Langhoff, S. R. (Technical Monitor)

1994-01-01

194

Mitochondrial DNA Copy Number and Exposure to Polycyclic Aromatic Hydrocarbons  

PubMed Central

Background Increased mitochondrial DNA copy number (mtDNAcn) is a biological response to mtDNA damage and dysfunction predictive of lung cancer risk. Polycyclic aromatic hydrocarbons (PAHs) are established lung carcinogens and may cause mitochondrial toxicity. Whether PAH exposure and PAH-related nuclear DNA (nDNA) genotoxic effects are linked with increased mtDNAcn has never been evaluated. Methods We investigated the effect of chronic exposure to PAHs on mtDNAcn in peripheral blood lymphocytes (PBLs) of 46 Polish male non-current smoking cokeoven workers and 44 matched controls, who were part of a group of 94 study individuals examined in our previous work. Subjects PAH exposure and genetic alterations were characterized through measures of internal dose (urinary 1-pyrenol), target dose [anti-benzo[a]pyrene diolepoxide (anti-BPDE)-DNA adduct], genetic instability (micronuclei, MN and telomere length [TL]) and DNA methylation [p53 promoter] in PBLs. mtDNAcn (MT/S) was measured using a validated real-time PCR method. Results Workers with PAH exposure above the median value (>3 µmol 1-pyrenol/mol creatinine) showed higher mtDNAcn [geometric means (GM) of 1.06 (unadjusted) and 1.07 (age-adjusted)] compared to controls [GM 0.89 (unadjusted); 0.89 (age-adjusted)] (p=0.029 and 0.016), as well as higher levels of genetic and chromosomal [i.e. anti-BPDE-DNA adducts (p<0.001), MN (p<0.001) and TL (p=0.053)] and epigenetic [i.e., p53 gene-specific promoter methylation (p<0.001)] alterations in the nDNA. In the whole study population, unadjusted and age-adjusted mtDNAcn was positively correlated with 1-pyrenol (p=0.043 and 0.032) and anti-BPDE-DNA adducts (p=0.046 and 0.049). Conclusions PAH exposure and PAH-related nDNA genotoxicity are associated with increased mtDNAcn. Impact The present study is suggestive of potential roles of mtDNAcn in PAH-induced carcinogenesis. PMID:23885040

Pavanello, Sofia; Dioni, Laura; Hoxha, Mirjam; Fedeli, Ugo; Mielzynska-Svach, Danuta; Baccarelli, Andrea A.

2013-01-01

195

Biotransformation of polycyclic aromatic hydrocarbons in marine polychaetes.  

PubMed

Deposit-feeding polychaetes constitute the dominant macrofauna in marine environments that tend to be depositional centers for organic matter and contaminants. Polychaetes are known to accumulate polycyclic aromatic hydrocarbons (PAHs) from both particulate and dissolved phases but less is known about the mechanisms underlying elimination of accumulated PAHs. An important pathway of elimination is through biotransformation which results in increased aqueous solubility of the otherwise hydrophobic PAHs. Biotransformation in marine polychaetes proceeds in a two phased process similar to those well studied in vertebrates, phase I enzymes belonging to the Cytochrome P450 (CYP) enzyme family, along with a few phase II enzymes have been identified in marine polychaetes. In this review we aim at highlighting advances in the mechanistic understanding of PAH biotransformation in marine polychaetes by including data obtained using analytical chemistry and molecular techniques. In marine polychaetes induction of CYP enzyme activity after exposure to PAHs and the mechanism behind this is currently not well established. Conflicting results regarding the inducibility of CYP enzymes from polychaetes have led to the suggestion that induction in polychaetes is mediated through a different mechanistic pathway, which is corroborated by the apparent lack of an AhR homologous in marine polychaetes. Also, none of the currently identified CYP genes from marine polychaetes are isoforms of those regulated by the AhR in vertebrates. Relatively few studies of phase II enzymes in marine polychaetes are currently available and most of these studies have not measured the activity of specific phase II enzymes and identified phase II metabolites but used an extraction technique only allowing determination of the overall amount of phase II metabolites. Studies in insects and various marine invertebrates suggest that in invertebrates, enzymes in the important phase II enzyme family, UDP-glucuronosyl transferases primarily use glucoside as co-substrate as opposed to the vertebrate cosubstrate glucuronic acid. Recent studies in marine polychaetes have however identified glucuronidation of PAHs indicating no mechanistic difference in co-substrate preference among UDP-glucuronosyl transferases between vertebrates and marine polychaetes but it might suggest a mechanistic difference between marine polychaetes and insects. PMID:18023473

Jørgensen, Anne; Giessing, Anders M B; Rasmussen, Lene Juel; Andersen, Ole

2008-03-01

196

Biomarkers in humans exposed to polycyclic aromatic hydrocarbons  

SciTech Connect

Polycyclic aromatic hydrocarbons (PAH) have been identified as a major source of carcinogenic risk in the coke-oven industry. This study evaluates following markers: personal exposure to PAH, DNA adducts, chromosomal aberrations and sister chromatid exchanges (SCE), glutathione S-transferase M1 (GSTM1) and N-acetyltransferase 2 (NAT2) polymorphisms. 23 top side coke-oven workers and 13 unexposed workers employed in the same plant at Kosice, Slovakia were studied. Personal monitors were used to measure carcinogenic PAH exposure during 8 h of working shift prior the collection of blood and urine samples. Personal exposure to eight carcinogenic PAHs ranged from 0.6 to 632 {mu}g/m{sup 3} and from 0.07 to 0.62 {mu}g/m{sup 3} for exposed and control groups, respectively. Based on the values of individual persons, the positive significant correlations were found between DNA adducts detected in WBC and LYM (Spearman r=0.451, p=0.044), between DNA adducts and SCE (r=0.363, p=0.034) and between AB.C. and SCE-H (SCE evaluated as the index of heterogeneity H-variance/mean: r=0.381, p=0.024). Using individual PAH exposure data the following significant correlations between exposure and biomarkers were found: WBC-DNA adducts (r=0.325;p=0.058);SCE-H (r=0.467, p=0.007). Groupwise comparison of the exposed and control groups (Mann-Whitney U-test) showed significantly increased values of SCE (6.71{+-}1.20 vs. 5.20 {+-}1.16, respectively) and DNA adducts in WBC and LYM (2.70{+-}0.74 vs 1.94{+-}0.51 adducts/10{sup 8} nucleotides; 2.46{+-}0.83 vs. 1.60{+-}0.32 adducts/10{sup 8}nucleotides, respectively). No influence of the smoking habits on the biomarkers was detectable in exposed or unexposed individuals. Multifactor analysis of variance taking into account confounding factors such as GSTM1, NAT2, diet and adjusting the data for age and smoking clearly showed the effect of exposure on DNA adducts, AB.C and SCE-H.

Binkova, B.; Topinka, J.; Mrackova, G. [Institute of Hygiene of Central Bohemia and Institute of Experimental Medicine, Prague (Czechoslovakia)] [and others

1997-10-01

197

Ecotoxicity of a polycyclic aromatic hydrocarbon (PAH)-contaminated soil.  

PubMed

Soil samples from a former cokery site polluted with polycyclic aromatic hydrocarbons (PAHs) were assessed for their toxicity to terrestrial and aquatic organisms and for their mutagenicity. The total concentration of the 16 PAHs listed as priority pollutants by the US Environmental Protection Agency (US-EPA) was 2634+/-241 mg/kgdw in soil samples. The toxicity of water-extractable pollutants from the contaminated soil samples was evaluated using acute (Vibrio fischeri; Microtox test, Daphnia magna) and chronic (Pseudokirchneriella subcapitata, Ceriodaphnia dubia) bioassays and the EC values were expressed as percentage water extract in the test media (v/v). Algal growth (EC50-3d=2.4+/-0.2% of the water extracts) and reproduction of C. dubia (EC50-7d=4.3+/-0.6%) were the most severely affected, compared to bacterial luminescence (EC50-30 min=12+/-3%) and daphnid viability (EC50-48 h=30+/-3%). The Ames and Mutatox tests indicated mutagenicity of water extracts, while no response was found with the umu test. The toxicity of the soil samples was assessed on the survival and reproduction of earthworms (Eisenia fetida) and collembolae (Folsomia candida), and on the germination and growth of higher plants (Lactuca sativa L.: lettuce and Brassica chinensis J.: Chinese cabbage). The EC50 values were expressed as percentage contaminated soil in ISO soil test medium (weight per weight-w/w) and indicated severe effects on reproduction of the collembola F. candida (EC50-28 d=5.7%) and the earthworm E. fetida (EC50-28 d=18% and EC50-56 d=8%, based on cocoon and juvenile production, respectively). Survival of collembolae was already affected at a low concentration of the contaminated soil (EC50-28 d=11%). The viability of juvenile earthworms was inhibited at much lower concentrations of the cokery soil (EC50-14 d=28%) than the viability of adults (EC50-14 d=74%). Only plant growth was inhibited (EC50-17d=26%) while germination was not. Chemical analyses of water extracts allowed us to identify inorganic water-extractable pollutants as responsible for toxicity on aquatic species, especially copper for effects on D. magna and C. dubia. The soil toxicity on collembolae and earthworms could be explained by 4 PAH congeners-fluorene, phenanthrene, pyrene, and fluoranthene. Yet, toxicity of the cokery soil as a whole was much lower than toxicity that could be deduced from the concentration of each congener in spiked soils, indicating that pollutants in the soil became less bioavailable with ageing. PMID:17382389

Eom, I C; Rast, C; Veber, A M; Vasseur, P

2007-06-01

198

Aromatic hydrocarbons in the atmospheric environment. Part III: personal monitoring  

NASA Astrophysics Data System (ADS)

As part of a larger study, personal sampling of the aromatic hydrocarbons benzene, toluene, ethylbenzene and the isomeric xylenes (BTEX) was carried out by 55 nonsmoking volunteers for a period of 14 days. Thirty-nine persons lived in a rural area near Hannover (Germany) with hardly any traffic at all, while 16 persons lived in a high-traffic city street in Hannover. The personal exposure level of the persons in the rural area (some commuting to Hannover) was: 2.9, 24.8, 2.4 and 7.7 ?g m -3 for benzene, toluene, ethylbenzene and the sum of xylenes, respectively, while the corresponding data for the high traffic city streets were 4.0, 22.2, 2.8 and 9.7 ?g m -3 (geometric means). Four microenvironments have been monitored which contribute to the total exposure to BTEX, i.e. the home, the outdoor air, the workplace and the car cabin. The most important microenvironment for non-working persons is the private home. The concentration of most BTEX in the private home is almost equal to the personal exposure level, demonstrating that the indoor pollution in the home makes by far the highest contribution to the total exposure. For working people (mostly office workers), the workplace is the second most important microenvironment contributing to the total BTEX exposure. Taking all working persons into consideration (independent of the location of their private home) the personal exposure level is higher by a factor of 1.2-1.4 than that of the workplace (for toluene this factor is 2.2). As already found by others, very high BTEX concentrations may be found in car cabins, in particular, if the engine is gasoline-driven. In the cabin of 44 cars in the rural/urban area average benzene concentrations (geometric mean) of 12/14 ?g m -3 and a maximum value of ˜550 ?g m -3 were found. On average, the participating volunteers drove their car for 45 min day -1 (i.e. 3% of the day). Nevertheless, the car cabin constitutes about 10% of the total benzene exposure. Refueling of the car during the 14-day sampling period has only a small effect on the personal exposure level.

Ilgen, E.; Levsen, K.; Angerer, J.; Schneider, P.; Heinrich, J.; Wichmann, H.-E.

199

Applications of electrochemically-modulated liquid chromatography (EMLC): Separations of aromatic amino acids and polycyclic aromatic hydrocarbons  

SciTech Connect

The research in this thesis explores the separation capabilities of a new technique termed electrochemically-modulated liquid chromatography (EMLC). The thesis begins with a general introduction section which provides a literature review of this technique as well as a brief background discussion of the two research projects in each of the next two chapters. The two papers which follow investigate the application of EMLC to the separation of a mixture of aromatic amino acids and of a mixture of polycyclic aromatic hydrocarbons (PAHs). The last section presents general conclusions and summarizes the thesis. References are compiled in the reference section of each chapter. The two papers have been removed for separate processing.

Deng, L.

1998-03-27

200

Combined ozonation and biodegradation for remediation of mixtures of polycyclic aromatic hydrocarbons in soil.  

PubMed

A study was conducted to investigate the feasibility of a combined treatment (i.e., ozonation and biodegradation) to overcome the inherent bacterial bioavailability limitation, and hence bioremediation limitation, of polycyclic aromatic hydrocarbons in soil. Ozonation was very efficient in the removal of naphthalene, fluorene, phenanthrene, and anthracene, but not for pyrene, chrysene, and benzo(a)pyrene from soil freshly spiked with the hydrocarbons. A similar result was obtained from coal tar-contaminated soil. Elimination of polycyclic aromatic hydrocarbons increased appreciably in sand containing 0.03% organic carbon, indicating the adverse effect of organic carbon on the efficiency of ozone treatment. In spiked and coal tar-contaminated soils, ozonation followed by biodegradation significantly increased the degradation of various polycyclic aromatic hydrocarbons including chrysene and benzo(a)pyrene which were not degraded by the test bacterial consortium alone. In particular, the effect of the combined treatment was more pronounced in coal tar-contaminated soil than in sterile soil spiked with hydrocarbons, probably due to the augmented biological activity of the introduced consortium. The results suggest that a combined treatment including ozonation and biodegradation may be a promising bioremediation technology in soil contaminated with mixtures of polycyclic aromatic hydrocarbons such as former manufactured gas plant sites. PMID:11194968

Nam, K; Kukor, J J

2000-01-01

201

Draft Genome Sequence of Marinomonas sp. Strain D104, a Polycyclic Aromatic Hydrocarbon-Degrading Bacterium from the Deep-Sea Sediment of the Arctic Ocean.  

PubMed

Marinomonas sp. strain D104 was isolated from a polycyclic aromatic hydrocarbon-degrading consortium enriched from deep-sea sediment from the Arctic Ocean. The draft genome sequence of D104 (approximately 3.83 Mbp) contains 62 contigs and 3,576 protein-encoding genes, with a G+C content of 44.8%. PMID:24459272

Dong, Chunming; Bai, Xiuhua; Lai, Qiliang; Xie, Yanrong; Chen, Xin; Shao, Zongze

2014-01-01

202

Polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and chlorinated pesticides in background air in central Europe - investigating parameters affecting wet scavenging of polycyclic aromatic hydrocarbons  

NASA Astrophysics Data System (ADS)

Concentrations of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and chlorinated pesticides (CPs) were measured in air and precipitation at a background site in central Europe. ? PAH concentrations in air and rainwater ranged from 0.7 to 327.9 ng m-3 and below analytical method detection limit (< MDL) to 2.1 × 103 ng L-1. The concentrations of PCBs and CPs in rainwater were < MDL. ? PCB and ? CP concentrations in air ranged from < MDL to 44.6 and < MDL to 351.7 pg m-3, respectively. The potential relationships between PAH wet scavenging and particulate matter and rainwater properties were investigated. The concentrations of ionic species in particulate matter and rainwater were significantly correlated, highlighting the importance of particle scavenging process. Overall, higher scavenging efficiencies were found for relatively less volatile PAHs, underlining the effect of analyte gas-particle partitioning on scavenging process. The PAH wet scavenging was more effective when the concentrations of ionic species were high. In addition, the elemental and organic carbon contents of the particulate matter were found to influence the PAH scavenging.

Shahpoury, P.; Lammel, G.; Holubová Šmejkalová, A.; Klánová, J.; P?ibylová, P.; Vá?a, M.

2014-10-01

203

Polycyclic aromatic hydrocarbon emission from straw burning and the influence of combustion parameters  

NASA Astrophysics Data System (ADS)

A simulated burning experiment was conducted in a tubular furnace system to examine the emission of polycyclic aromatic hydrocarbons (PAHs) from the burning of rice and bean straw, and the influence of combustion parameters was investigated. Total emission amounts of 16 PAHs (?PAHs) from the burning of rice and bean straw ranged from 9.29 to 23.6 ?g g -1 and from 3.13 to 49.9 ?g g -1, respectively, which increased with the increase of temperatures from 200 to 700 °C. The contribution of combustion to individual PAH yields was about 80.6-100%, which was generally increased with the increase of burning temperature. Moisture content in straw had a negative effect on PAH formation, especially on PAHs with low molecular weight. ?PAHs emission amounts decreased by 78.2% for bean straw with a moisture content of 30% in comparison with that for dried straw. In addition, PAH emission amounts increased with the increase of O 2 content in supplied air and then decreased, which showed a maximum emission at O 2 content of 40%. The source fingerprint of PAHs in emission from straw burning was established, which showed that naphthalene accounted for 35.0 ± 7.4% of ?PAHs. Based on the experimental data, emission amounts of ?PAHs from the burning of rice and bean straw were estimated to be 320-357 and 32.5-76.0 tons to ambient air per year in China, respectively.

Lu, Hao; Zhu, Lizhong; Zhu, Nali

204

Influence of the bioaccessible fraction of polycyclic aromatic hydrocarbons on the ecotoxicity of historically contaminated soils.  

PubMed

Sequential supercritical fluid extraction together with a two-site desorption model were employed to estimate the bioaccessible fraction of polycyclic aromatic hydrocarbons (PAHs) in four historically contaminated soils. The ecotoxicity of the soils was assayed by four different contact tests. The same soils were exposed to exhaustive extraction and the extracts were returned to the soils to ensure total 100% bioaccessibility of the pollutants. Then the soils were assayed again. Statistical evaluation revealed that the predicted bioaccessible PAHs generally correlated with the ecotoxicity responses of the tests. The estimated bioaccessible fractions varied from 10 to 98%. This value increased for PAHs with higher lipophilicity and showed no correlation with the organic carbon content in the soils. The ecotoxicity tests in the study indicated different sensitivity toward PAHs and the tests employing Heterocypris incongruens and Eisenia fetida were found to be more suitable than Lemna minor and Vibrio fischeri. Mortality and growth inhibition of ostracods correlated with all the types of PAHs and earthworm growth inhibition and mortality were preferentially sensitive to PAHs with only 3-4 aromatic rings. Determination of the biota-soil accumulation factors indicated that the earthworm growth inhibition corresponded to increased accumulation of PAHs in the earthworm tissue. PMID:23611796

?van?arová, Monika; K?esinová, Zdena; Cajthaml, Tomáš

2013-06-15

205

The bioaccumulation of polynuclear aromatic hydrocarbons by benthic invertebrates in an intertidal marsh  

SciTech Connect

Biota-sediment accumulation factors (BSAF; concentration in organism lipid/concentration in sediment on an organic carbon basis) of polyaromatic hydrocarbons varied with season and along an intertidal gradient in a coastal marsh in San Francisco Bay. The BSAFs were lowest during the local rainy season. During the dry season, BSAFs were lowest in the high intertidal zone closest to shore. Significant differences among species groups were also observed; BSAFs were lowest in polychaetes and highest in the Asian clam (Potamocorbula amurensis), varying over almost three orders of magnitude. The BSAFs decreased with increasing percent fines in the sediments and with PAH concentrations on an organic carbon basis. The authors suggest that a determining variable is the content of highly aromatic soot particles, which increases during periods of surface runoff and which is expected in the dry season to be highest in the high intertidal zone where these finer particles preferentially accumulate. Correlations of BSAFs with the ratio of the logarithm of the activity coefficients in porewaters to those in sediments were generally stronger than with log K{sub ow}, indicating a limitation of octanol as a surrogate for sediment organic carbon or organism lipid. These observations qualify but also strengthen the concept of equilibrium partitioning as the determining factor in bioaccumulation by benthic organisms of nonpolar organic compounds for sediments; the assumption that organic carbon can be considered in generic terms without allowance for aromaticity and probably other factors as well, must, however, be reconsidered.

Maruya, K.A.; Risebrough, R.W.; Horne, A.J. [Univ. of California, Berkeley, CA (United States). Dept. of Civil and Environmental Engineering

1997-06-01

206

Anomalously high efficiencies for electronic energy transfer from saturated to aromatic hydrocarbons at low aromatic concentrations  

SciTech Connect

The absolute efficiency of electric energy transfer from cis-decalin excited at 161 nm to 2,5-diphenyloxazole (PPO) has been measured over a PPO concentration range from 1.0 [times] 10[sup [minus]2] to 2.0 [times] 10[sup [minus]5] M via measurements of both the cis-decalin and the PPO fluorescence. At concentrations above ca. 10[sup [minus]3] M, the normal fluorescing state of cis-decalin plays the dominant role in the energy transfer. At lower concentrations, however, there appears to be an important contribution from some other nonfluorescing state of cis-decalin. The fraction of PPO fluorescence generated by this dark state rises from ca.10% at 0.01 M to ca. 70% at 2 [times] 10[sup [minus]5] M. The effects of addition of O[sub 2] of dilution with isooctane, and of cooling to [minus]35[degrees]C on the quantum yield of this process are reported. The results obtained here confirm earlier results with other saturated hydrocarbon donor + aromatic acceptor systems that have suggested the existence of a dark donor state that dominates the transfer process at low acceptor concentrations via some anomalously efficient mechanism. For the system cis-decalin + PPO at 21[degrees]C, the transfer probability for this process at the lowest concentration studied of 2 [times] 10[sup [minus]5] M is 2.5 [times] 10[sup [minus]3] per photon absorbed and 0.060 per dark state produced. 34 refs., 13 figs., 6 tabs.

Yiming Wang; Johnston, D.B.; Lipsky, S. (Univ. of Minnesota, Minneapolis (United States))

1993-01-14

207

Detection of mid-infrared Aromatic Hydrocarbon Emission Features from the Small Magellanic Cloud  

E-print Network

The mid-infrared (5-16 micron) spectral energy distribution for an individual quiescent molecular cloud in the Small Magellanic Cloud (SMC) was observed using ISOCAM. The spectrum is dominated by broad emission bands at 6.2, 7.7, and 11.3 microns, with weaker bands at 8.6 and 12.7 microns. As these are the same bands, with similar shape and relative strengths, as observed in the ISM of our Galaxy, the same carriers must exist in both galaxies. The carriers are widely consider to be large molecules or clusters of aromatic hydrocarbons, which absorb ultraviolet and visible photons and emit mid-infrared photons during high-temperature pulses. Based on the brightness of the mid-infrared emission and the estimated strength of the radiation field in the SMC, the absorption by aromatic hydrocarbons is of order 10% of total dust absorption, comparable to the case for Galactic dust. Ultraviolet observations of extinction of most SMC stars have shown that dust in the SMC does not absorb in the 2175 Angstrom feature that is so prominent in Milky Way extinction. If aromatic hydrocarbons and featureless extinction curves were ubiquitous in the SMC, then we would conclude that aromatic hydrocarbons are not the carriers of the 2175 Angstrom feature. However, SMC extinction curve measurements are biased toward hot, luminous stars, where aromatic hydrocarbons are destroyed, so that the absence of the 2175 Angstrom bump may not be typical of SMC dust. The presence of aromatic hydrocarbons in the SMC further demonstrate that these molecules exist even in an interstellar medium with an order-of-magnitude lower metallicity than in the disk of the Milky Way.

William T. Reach; Francois Boulanger; Alessandra Contursi; James Lequeux

2000-07-25

208

Early-Life Exposure to Polycyclic Aromatic Hydrocarbons and ADHD Behavior Problems  

PubMed Central

Importance Polycyclic aromatic hydrocarbons are widespread urban air pollutants from combustion of fossil fuel and other organic material shown previously to be neurotoxic. Objective In a prospective cohort study, we evaluated the relationship between Attention Deficit Hyperactivity Disorder behavior problems and prenatal polycyclic aromatic hydrocarbon exposure, adjusting for postnatal exposure. Materials and Methods Children of nonsmoking African-American and Dominican women in New York City were followed from in utero to 9 years. Prenatal polycyclic aromatic hydrocarbon exposure was estimated by levels of polycyclic aromatic hydrocarbon- DNA adducts in maternal and cord blood collected at delivery. Postnatal exposure was estimated by the concentration of urinary polycyclic aromatic hydrocarbon metabolites at ages 3 or 5. Attention Deficit Hyperactivity Disorder behavior problems were assessed using the Child Behavior Checklist and the Conners Parent Rating Scale- Revised. Results High prenatal adduct exposure, measured by elevated maternal adducts was significantly associated with all Conners Parent Rating Scale-Revised subscales when the raw scores were analyzed continuously (N?=?233). After dichotomizing at the threshold for moderately to markedly atypical symptoms, high maternal adducts were significantly associated with the Conners Parent Rating Scale-Revised DSM-IV Inattentive (OR?=?5.06, 95% CI [1.43, 17.93]) and DSM-IV Total (OR?=?3.37, 95% CI [1.10, 10.34]) subscales. High maternal adducts were positivity associated with the DSM-oriented Attention Deficit/Hyperactivity Problems scale on the Child Behavior Checklist, albeit not significant. In the smaller sample with cord adducts, the associations between outcomes and high cord adduct exposure were not statistically significant (N?=?162). Conclusion The results suggest that exposure to polycyclic aromatic hydrocarbons encountered in New York City air may play a role in childhood Attention Deficit Hyperactivity Disorder behavior problems. PMID:25372862

Perera, Frederica P.; Chang, Hsin-wen; Tang, Deliang; Roen, Emily L.; Herbstman, Julie; Margolis, Amy; Huang, Tzu-Jung; Miller, Rachel L.; Wang, Shuang; Rauh, Virginia

2014-01-01

209

Degradation of polycyclic aromatic hydrocarbons with three to seven aromatic rings by higher fungi in sterile and unsterile soils  

Microsoft Academic Search

Seven commercial 3- to 7-ring (R) polycyclic aromatic hydrocarbons (PAH) as well as PAH derived from lignite tar were spiked into 3 soils (0.8 to 9.7% of organic carbon). The disappearance of the original PAH was determined for the freshly spiked soils, for soils incubated for up to 287 d with their indigenous microflora, and for autoclaved, unsterile and pasteurized

Gerhard Gramss; Klaus-Dieter Voigt; Brigitta Kirsche

1999-01-01

210

Genomic analysis of polycyclic aromatic hydrocarbon degradation in Mycobacterium vanbaalenii PYR-1  

Microsoft Academic Search

Mycobacterium vanbaalenii PYR-1 is well known for its ability to degrade a wide range of high-molecular-weight (HMW) polycyclic aromatic hydrocarbons\\u000a (PAHs). The genome of this bacterium has recently been sequenced, allowing us to gain insights into the molecular basis for\\u000a the degradation of PAHs. The 6.5 Mb genome of PYR-1 contains 194 chromosomally encoded genes likely associated with degradation\\u000a of aromatic

Seong-Jae Kim; Ohgew Kweon; Richard C. Jones; Ricky D. Edmondson; Carl E. Cerniglia

2008-01-01

211

Polycyclic Aromatic Hydrocarbons and n-alkanes in sediments of the Upper Scheldt River Basin: contamination levels and source apportionment  

E-print Network

Polycyclic Aromatic Hydrocarbons and n-alkanes in sediments of the Upper Scheldt River Basin River at Wervik and the Espierre Canal), were analysed for n-alkanes and polycyclic aromatic hydrocarbons (PAHs). Total n-alkane and PAH concentrations in all the sampled cores ranged from 2.8 to 29 mg kg

Boyer, Edmond

212

The aromatic hydrocarbon resins with various hydrogenation degrees Part 1. The phase behavior and miscibility with polybutadiene and with polystyrene  

Microsoft Academic Search

The miscibility of hydrogenated aromatic hydrocarbon resin (HR) with polybutadiene (PB) and polystyrene (PS) was investigated using turbidity measurement. Hereafter, the aromatic hydrocarbon resin having nine carbon atoms per monomer is referred to as C-9 resin. We found that C-9 resin, which has only a limited (or partial) miscibility with PB, became completely miscible with PB as the degree of

Jin Kon Kim; Du Yeol Ryu; Kyung-Hee Lee

2000-01-01

213

Characterization of a naphthalene dioxygenase endowed with an exceptionally broad1 substrate specificity towards polycyclic aromatic hydrocarbons2  

E-print Network

and might inhibit PAH degradation. In single turnover13 reactions, ht-PhnI alone catalyzed PAH hydroxylation, isopropyl--D-thiogalactopyranoside;7 PAH; polycyclic aromatic hydrocarbon;8 RedB356, reductase component is responsible for the2 initial attack of a range of polycyclic aromatic hydrocarbons (PAHs) composed of up

Paris-Sud XI, Université de

214

Polycyclic aromatic hydrocarbons (PAH) and phenolic substances in meat products smoked with different types of wood and smoking spices.  

PubMed

The contents of polycyclic aromatic hydrocarbons (15+1 EU PAH) and phenolic substances (guaiacol, 4-methylguaiacol, syringol, eugenol, and trans-isoeugenol) were investigated in smouldering-smoked Frankfurters and mini-salamis. For the 51 smoking experiments wood chips of oak, poplar, hickory, spruce, fir, alder, beech, and beech with an apple-smoking spice mix, cherry-smoking spice mix, and a mix of juniper berries and bay leaves were tested. The use of poplar and hickory led to a decrease in the PAH contents in the range of 35-55% compared to the commonly used beech wood. Higher PAH contents by using softwood were not observed. The use of the rapidly growing poplar seems to be a reasonable approach for reducing the PAH contents in smoked meat products. Furthermore, the sum contents of the five phenolic substances in sausages smoked with poplar were higher, or only slightly lower, when compared to the use of beech. PMID:23561196

Hitzel, Alexander; Pöhlmann, Margarete; Schwägele, Fredi; Speer, Karl; Jira, Wolfgang

2013-08-15

215

High-resolution electron spectroscopy, preferential metal-binding sites, and thermochemistry of lithium complexes of polycyclic aromatic hydrocarbons  

NASA Astrophysics Data System (ADS)

Polycyclic aromatic hydrocarbons are model systems for studying the mechanisms of lithium storage in carbonaceous materials. In this work, Li complexes of naphthalene, pyrene, perylene, and coronene were synthesized in a supersonic metal-cluster beam source and studied by zero-electron-kinetic-energy (ZEKE) electron spectroscopy and density functional theory calculations. The adiabatic ionization energies of the neutral complexes and frequencies of up to nine vibrational modes in the singly charged cations were determined from the ZEKE spectra. The metal-ligand bond energies of the neutral complexes were obtained from a thermodynamic cycle. Preferred Li/Li+ binding sites with the aromatic molecules were determined by comparing the measured spectra with theoretical calculations. Li and Li+ prefer the ring-over binding to the benzene ring with a higher ?-electron content and aromaticity. Although the ionization energies of the Li complexes show no clear correlation with the size of the aromatic molecules, the metal-ligand bond energies increase with the extension of the ?-electron network up to perylene, then decrease from perylene to coronene. The trends in the ionization and metal-ligand bond dissociation energies of the complexes are discussed in terms of the orbital energies, local quadrupole moments, and polarizabilities of the free ligands and the charge transfer between the metal atom and aromatic molecules.

Lee, Jung Sup; Krasnokutski, Serge A.; Yang, Dong-Sheng

2011-01-01

216

THE EFFECT OF ROUTE OF ADMINISTRATION OF POLYCYCLIC AROMATIC HYDROCARBONS ON DNA ADDUCTION AND CYTOGENETIC DAMAGE IN PERIPHERAL BLOOD LYMPHOCYTES OF MICE AND RATS  

EPA Science Inventory

The effect of route of administration of polycyclic aromatic hydrocarbons on DNA adduction and cytogenetic damage in peripheral blood lymphocytes of mice and rats Experiments were designed to investigate how the route of exposure to polycyclic aromatic hydrocarbons (PA...

217

New SERS Substrates For Polycyclic Aromatic Hydrocarbon (PAH) Detection: Towards Quantitative SERS Sensors For Environmental Analysis  

SciTech Connect

In the investigation of chemical pollutions, such as PAHs (Polycyclic Aromatic Hydrocarbons) at low concentration in aqueous medium, surface-enhanced Raman scattering (SERS) stands for an alternative to the inherent low cross-section of normal Raman scattering. Indeed, SERS is a very sensitive spectroscopic technique due to the excitation of the surface plasmon modes of the nanostructured metallic film.

Peron, O. [Service Interfaces et Capteurs, Departement Recherches et Developpements Technologiques, IFREMER, BP70, 29280 Plouzane (France); Laboratoire de Nanotechnologie et d'instrumentation Optique, Institut Charles Delaunay, FRE 2848, Universite de technologie de Troyes, 12 rue Marie Curie, 10010 Troyes (France); Rinnert, E.; Compere, C. [Service Interfaces et Capteurs, Departement Recherches et Developpements Technologiques, IFREMER, BP70, 29280 Plouzane (France); Toury, T. [Laboratoire de Nanotechnologie et d'instrumentation Optique, Institut Charles Delaunay, FRE 2848, Universite de technologie de Troyes, 12 rue Marie Curie, 10010 Troyes (France); Lamy de la Chapelle, M. [Laboratoire CSPBAT (FRE 3043), UFR SMBH, Universite Paris XIII, 74 rue Marcel Cachin, 93017 Bobigny (France)

2010-08-06

218

Application of aqueous saponin on the remediation of polycyclic aromatic hydrocarbons-contaminated soil  

Microsoft Academic Search

The aim of this research was to evaluate the feasibility of aqueous saponin for the removal and biodegradation of polycyclic aromatic hydrocarbons (PAHs) from contaminated soil. Dissolution test confirmed the ability of saponin to increase the apparent solubility of the tested 3–5 rings PAH above the critical micelle concentration (approximately 1000 mg\\/L). Microbial test with pure culture of Sphingomonas sp.

Takayuki Kobayashi; Hirohisa Kaminaga; Ronald R. Navarro; Yosuke Iimura

2012-01-01

219

1 Solvent-Extractable Polycyclic Aromatic Hydrocarbons in Biochar: 2 Influence of Pyrolysis Temperature and Feedstock  

E-print Network

1 Solvent-Extractable Polycyclic Aromatic Hydrocarbons in Biochar: 2 Influence of Pyrolysis, it is not known how variations in pyrolysis temperature and feedstock type 13 affect concentration and composition of phenanthrene and 16 anthracene in grass and wood chars produced in 100 °C increments across a temperature 17

220

Toxicity of polycyclic aromatic hydrocarbons. (Latest citations from Pollution abstracts). Published Search  

SciTech Connect

The bibliography contains citations concerning the toxicity and biochemical effects of aromatic polycyclic hydrocarbons. Citations discuss air, water, soil, and sediment pollution and control. Topics include vehicle emissions and control, pollutant pathways, carcinogens and mutagenic activity, and photoinduced toxicity. Food contamination, environmental monitoring, and soil contamination along highways are examined. (Contains 50-250 citations and includes a subject term index and title list.)

NONE

1995-07-01

221

Toxicity of aromatic polycyclic hydrocarbons. (Latest citations from the Life Sciences Collection data base). Published Search  

SciTech Connect

The bibliography contains citations concerning the toxicity and biochemical effects of aromatic polycyclic hydrocarbons. Topics include effects on metabolism and liver activity, cellular responses, binding characteristics, and the occurrence and path of the compounds in food chains. Bioaccumulation studies in specific areas, and isolation and detection techniques are also considered. (Contains 250 citations and includes a subject term index and title list.)

Not Available

1992-05-01

222

Toxicity of aromatic polycyclic hydrocarbons. (Latest citations from the Life Sciences Collection database). Published Search  

SciTech Connect

The bibliography contains citations concerning the toxicity and biochemical effects of aromatic polycyclic hydrocarbons. Topics include effects on metabolism and liver activity, cellular responses, binding characteristics, and the occurrence and path of the compounds in food chains. Bioaccumulation studies in specific areas, and isolation and detection techniques are also considered. (Contains 250 citations and includes a subject term index and title list.)

Not Available

1993-11-01

223

Method for Measuring the Temperature Dependence of the Henry's Law Constant of Selected Polycyclic Aromatic Hydrocarbons  

Microsoft Academic Search

The Henry's Law Constant (HLC) is an important thermodynamic constant needed to model air-water exchange of contaminants such as polycyclic aromatic hydrocarbons (PAHs). However, few direct HLC measurements have been reported for PAHs. A gas-stripping apparatus was constructed to allow gaseous and dissolved phase PAH concentrations to be measured over time. HLC was calculated by two methods: measuring PAH loss

Holly A. Bamford; Dianne L. Poster; Joel E. Baker

1999-01-01

224

Polycyclic aromatic hydrocarbons and polychlorinated biphenyls in urban soils from Kathmandu, Nepal  

Microsoft Academic Search

Kathmandu, the capital of Nepal, faces increasing environmental problems such as heavy air pollution and lack of proper waste management. The aim of this study was to examine if the soils are also affected by pollution, with the focus on polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). The sum of 20 PAHs in surface soils ranged between 184 and

B. Aichner; B. Glaser; W. Zech

2007-01-01

225

Risk of polycyclic aromatic hydrocarbon (PAH) exposure from ingested food: The Azerbaijan case study  

Microsoft Academic Search

Risks due to polycyclic aromatic hydrocarbons (PAHs) exposure from food consumption for the population of Azerbaijan were determined using deterministic and probabilistic methods. The guidelines and methods described and presented in the United States Environmental Protection Agency (U.S. EPA) Risk Assessment Guidance for Superfund (RAGS) Part A was used in performing the risk assessments. The current study utilized concentration data

Oke C. Nwaneshiudu; Robin L. Autenrieth; Thomas J. McDonald; Kirby C. Donnelly; Erica D. Degollado; Afraa A. Abusalih

2007-01-01

226

REDUCTIVE TRANSFORMATIONS OF HALOGENATED AROMATIC HYDROCARBONS IN ANAEROBIC SEDIMENT-WATER SYSTEMS: KINETICS, MECHANISMS, AND PRODUCTS  

EPA Science Inventory

The degradation of several classes of halogenated aromatic hydrocarbons in methanogenic sediment-water systems was examined in laboratory studies. everal transformation processes were shown to occur, leading to formation of a variety of products. n the study, a clear distinction ...

227

A UV spectroscopic method for monitoring aromatic hydrocarbons dissolved in water  

Microsoft Academic Search

An enhanced UV spectrometric method is applied to trace measurements of aromatic hydrocarbons dissolved in water. This approach gains selectivity and sensitivity by the use of optically generated first and second derivatives of transmission spectra. The augmented spectroscopic technique is combined with chemometric algorithms like principal component regression or partial least squares which are used for calibration of the spectrometer

F. Vogt; M. Tacke; M. Jakusch; B. Mizaikoff

2000-01-01

228

Effects of Polycyclic Aromatic Hydrocarbons in Northern Bobwhite Quail (Colinus virginianus)  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAH) are ubiquitous contaminants of aquatic and terrestrial ecosystems, and are known to induce biochemical alterations in exposed organisms. Aside from a variety of adverse physiological effects associated with exposure to petroleum products, oils, and oil sludges, little is known about the effects of individual PAH on birds. Acute toxicity of naphthalene, pyrene, and benz[a]anthracene (BAA) was

John M. Brausch; Brett R. Blackwell; Blake N. Beall; Cynthia Caudillo; Venkata Kolli; Céline Godard-Codding; Stephen B. Cox; George Cobb; Philip N. Smith

2010-01-01

229

Anaerobic Degradation of Polycyclic Aromatic Hydrocarbons and Alkanes in Petroleum-Contaminated Marine Harbor Sediments  

Microsoft Academic Search

Although polycyclic aromatic hydrocarbons (PAHs) have usually been found to persist under strict anaer- obic conditions, in a previous study an unusual site was found in San Diego Bay in which two PAHs, naphthalene and phenanthrene, were oxidized to carbon dioxide under sulfate-reducing conditions. Further investigations with these sediments revealed that methylnaphthalene, fluorene, and fluoranthene were also anaerobically oxidized to

JOHN D. COATES; JOAN WOODWARD; JON ALLEN; PAUL PHILP; DEREK R. LOVLEY

1997-01-01

230

Surfactants and Bacterial Bioremediation of Polycyclic Aromatic Hydrocarbon Contaminated Soil—Unlocking the Targets  

Microsoft Academic Search

The activities of man produce significant levels of toxic polycyclic aromatic hydrocarbon compounds (PAHs), which have been identified as excellent candidates for biodegradative removal from contaminated sites. PAHs strongly sorb to soil particles and can also partition into a nonaqueous phase, often limiting bioavailability. In this context, synthetic surfactants and biosurfactants will be discussed as a means to mobilize and

Roy Elliot; Naresh Singhal; Simon Swift

2010-01-01

231

Polycyclic aromatic hydrocarbons in soil and plant samples from the vicinity of an oil refinery  

Microsoft Academic Search

Soil samples, and samples of leaves of Plantago major (great plantain) and grass (mixed species) were collected from the vicinity of an oil refinery in Zelzate, Belgium, and analysed for seven polycyclic aromatic hydrocarbons (PAHs). The samples from the site adjacent to the refinery (site 1) contained very high total PAH-concentrations: namely 300, 8 and 2 ?g\\/g dry wt. for

Martine I. Bakker; Berta Casado; Judith W. Koerselman; Johannes Tolls; Chris Kollöffel

2000-01-01

232

Probabilistic Risk Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in Produced Water  

Microsoft Academic Search

The produced water extracted during oil and gas production includes formation water, injected water, small volumes of condensed water, and any chemical added during the oil\\/water separation process. Produced water contains both organic and inorganic constituents, and several studies have been conducted in the past to assess their risk. The toxicity and persistence of polycyclic aromatic hydrocarbons (PAHs) in produced

Khaled H. Chowdhury; Tahir Husain; Brian Veitch; Kelly Hawboldt

2009-01-01

233

Polycyclic Aromatic Hydrocarbons in Louisiana Rivers and Coastal Environments: Source Fingerprinting and Forensic Analysis  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs), many of which are toxic and recalcitrant compounds, are ubiquitous in rivers and coastal environments. Anthropogenic introduction of these chemicals into the environment compromises the assessment of cleanup responsibility and environmental damage liability. Natural background and anthropogenic PAHs in Louisiana coast and major rivers were differentiated based on PAH profiles in samples selected from a pool

Javed Iqbal; Edward B. Overton; David Gisclair

2008-01-01

234

Catalytic cracking of aromatic hydrocarbons. Final report, October 1984March 1986  

Microsoft Academic Search

Iron containing minerals and chars were screened as cracking catalysts for aromatic hydrocarbons (AHC) in simulated gasifier effluents. Catalytic activities of six minerals and two chars were measured and used to infer fundamental hetereogeneous rate constants using measured properties of the pore structure of the solids. Measurements were made for 200 ppM and 2000 ppM benzene cracking over the temperature

G. A. Simons; D. O. Ham; G. A. Moniz

1986-01-01

235

CHARACTERIZATION OF EMISSIONS OF PAH'S (POLYNUCLEAR AROMATIC HYDROCARBON) FROM RESIDENTIAL COAL-FIRED SPACE HEATERS  

EPA Science Inventory

The paper gives results of a joint emissions testing and analysis program--the U.S. EPA and the State of Vermont--to determine polynuclear aromatic hydrocarbon (PAH), particulate, sulfur dioxide (SO2), and carbon monoxide (CO) emissions from two coal-fired residential space heate...

236

Polycyclic aromatic hydrocarbons in soils of an industrial area of China: multivariate analyses and geostatistics  

Microsoft Academic Search

Tianjin Bin Hai New Area (BHNA) is the third largest economic zone in China. This is an older industrial area that has been developing rapidly but with many historic sources of contamination. The concentrations of 16 individual polycyclic aromatic hydrocarbons (PAHs) listed for priority control by the US EPA were quantified in 105 surface soil samples by the use of

Jing Li; Yonglong Lu; Wentao Jiao; Tieyu Wang; Wei Luo; John P. Giesy

2010-01-01

237

Spectrochemical Evaluation of Diisopropylamine as a Selective Fluorescence Quenching Agent of Polycyclic Aromatic Hydrocarbons in Acetonitrile  

Microsoft Academic Search

The ability of diisopropylamine to selectively quench the fluorescence intensity of nonalternant as opposed to alternant polycyclic aromatic hydrocarbons (PAHs) dissolved in acetonitrile was investigated. Sixteen alternant PAHs and 14 nonalternant PAHs were examined. Five PAHs, which contain a fixed double bond in the cyclopenta ring, were also included in this study. The experimental results indicated, with few exceptions, that

Chunfeng Mao; Charlotte L. Larson; Sheryl A. Tucker

2002-01-01

238

EPOXIDE RING OPENING AND RELATED REACTIVITIES OF CYCLOPENTAL POLYCYCLIC AROMATIC HYDROCARBONS: QUANTUM MECHANICAL STUDIES  

EPA Science Inventory

For a series of cyclopenta-polynuclear aromatic hydrocarbons, epoxidated in the cyclopenta ring, semi-empirical AM1 calculations, and single point ab initio calculations using the 3-21g split valence basis set, have been performed for the each carbocation that might be formed by ...

239

ELECTRON AFFINITIES OF POLYNUCLEAR AROMATIC HYDROCARBONS AND NEGATIVE ION CHEMICAL IONIZATION SENSITIVITIES  

EPA Science Inventory

Negative-ion chemical-ionization mass spectrometry (NICI MS) has the potential to be a very useful technique in identifying various polycyclic aromatic hydrocarbons (PAHs) in soil and sediment samples. Some PAHs give much stronger signals under NICI MS conditions than others. On ...

240

COMPARISON OF QUANTUM MECHANICAL METHODS TO COMPUTE THE BIOLOGICALLY RELEVANT REACTIVITIES OF CYCLOPENTA POLYCYCLIC AROMATIC HYDROCARBONS  

EPA Science Inventory

In computational studies to understand the interaction of polycyclic aromatic hydrocarbons (PAHS) with biomolecular systems, the semi-empirical method AM1 has been used to determine the geometry of the PAH, its metabolites and relevant intermediates. umber of studies have shown t...

241

COMPARATIVE STUDIES OF THE EFFECT OF POLYCYCLIC AROMATIC HYDROCARBON GEOMETRY ON THE HYDROLYSIS OF DIOL EPOXIDES  

EPA Science Inventory

Comparative studies of the effect of polycyclic aromatic hydrocarbon geometry on the hydrolysis of diol epoxides The interaction of the diol epoxides (DEs) of both planar and non-planar PAHs with water have been examined using quantum mechanical and molecular dynamics. Th...

242

Influence of Traffic Emissions on the Carcinogenic Polycyclic Aromatic Hydrocarbons in Outdoor Breathable Particles  

Microsoft Academic Search

Because polycyclic aromatic hydrocarbons (PAHs) have been proven to be toxic, mutagenic, and\\/or carcinogenic, there is widespread interest in analyzing and evaluating exposure to PAHs in atmospheric environments influenced by different emission sources. Because traffic emissions are one of the biggest sources of fine particles, more information on carcinogenic PAHs associated with fine particles needs to be provided. Aiming to

Klara Slezakova; Dionísia Castro; Maria C. Pereira; Simone Morais; Cristina Delerue-Matos; Maria C. Alvim-Ferraz; Walter Nakaema; Wellington Jesus; Maria Jorge; Rauda Mariani; Catherine Barton; Charles Zarzecki; Mark Russell; Marjaleena Aatamila; Pia Verkasalo; Maarit Korhonen; Marja Viluksela; Kari Pasanen; Pekka Tiittanen; Aino Nevalainen; Li Rong; Peter Nielsen; Guoqiang Zhang; Yi-Ming Kuo; Juu-En Chang; Kun-Yu Chang; Chih-C. Chao; Yeu-Juin Tuan; Guo-Ping Chang-Chien; Yongping Li; Guohe Huang; Arhontoula Chatzilazarou; Evangelos Katsoyannos; Olga Gortzi; Stavros Lalas; Yiannis Paraskevopoulos; Euthalia Dourtoglou; John Tsaknis; Tarek Abichou; Jeremy Clark; Sze Tan; Jeffery Chanton; Gary Hater; Roger Green; Doug Goldsmith; Morton Barlaz; Nathan Swan; Gang Sun; Huiqing Guo; Jonathan Peterson; Zhengmin Qian; Hung-Mo Lin; Walter Stewart; Nirav Shah; Linli Kong; Fen Xu; Denjin Zhou; Zhicao Zhu; Qingci He; Shengwen Liang; Weiqing Chen; Chungsying Lu; Hsunling Bai; Fengsheng Su; Wenfa Chen; Jyh Hwang; Hsiu-Hsia Lee; Judith Chow; John Watson; Douglas Lowenthal; Lung-Wen Chen; Nehzat Motallebi

2010-01-01

243

CHEMICAL CHARACTERIZATION OF POLYNUCLEAR AROMATIC HYDROCARBON DEGRADATION PRODUCTS FROM SAMPLING ARTIFACTS  

EPA Science Inventory

The objective of the study was to characterize the polar components, mainly polynuclear aromatic hydrocarbon (PAH) derivatives, in air samples and to determine whether these compounds are from sampling artifacts or from the sampled air. A literature survey was conducted to review...

244

POLYHALOGENATED AROMATIC HYDROCARBONS AND METABOLITES: RELATION TO CIRCULATING THYROID HORMONE AND RETINOL IN NESTLING BALD EAGLES  

E-print Network

POLYHALOGENATED AROMATIC HYDROCARBONS AND METABOLITES: RELATION TO CIRCULATING THYROID HORMONE metabolites or analogues and relationships with circulating thyroid hormones and retinols in plasma from was congruent with results from nine of 14 other published avian laboratory and field studies. Free thyroid

245

Atmospheric inputs of selected polycyclic aromatic hydrocarbons and polychlorinated biphenyls to southern Chesapeake Bay  

Microsoft Academic Search

Atmospheric and precipitation levels of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) were measured at a rural site in southern Chesapeake Bay throughout 1991. Wet depositional inputs of PAHs and PCBs to the lower Bay were directly determined from the data; dry deposition and gas exchange fluxes were also estimated for PAHs. Notable seasonal variability in the atmospheric concentrations

Rebecca M. Dickhut; Kurt E. Gustafson

1995-01-01

246

Polynuclear aromatic hydrocarbons (PAHs) mediate cadmium toxicity to an emergent wetland species  

Microsoft Academic Search

Growth and pollutant removal by emergent wetland plants may be influenced by interactions among mixed pollutants in constructed wetlands. A glasshouse experiment was conducted to investigate interactive effects of cadmium (Cd)×polynuclear aromatic hydrocarbons (PAHs)×plant treatments on growth of Juncus subsecundus, Cd and PAH removal from soil and the total number of microorganisms in soil. Growth and biomass of J. subsecundus

Zhenhua Zhang; Zed Rengel; Kathy Meney; Ljiljana Pantelic; Radmila Tomanovic

2011-01-01

247

Characterization of polycyclic aromatic hydrocarbons in motor vehicle fuels and exhaust emissions  

Microsoft Academic Search

Motor vehicles are a significant source of polycyclic aromatic hydrocarbon (PAH) emissions. Improved understanding of the relationship between fuel composition and PAH emissions is needed to determine whether fuel reformulation is a viable approach for reducing PAH emissions. PAH concentrations were quantified in gasoline and diesel fuel samples collected in summer 1997 in northern California. Naphthalene was the predominant PAH

Linsey C. Marr; Thomas W. Kirchstetter; Robert A. Harley; S. K. Hammond; A. H. Miguel

1999-01-01

248

23. Method development for the determination of polycyclic aromatic hydrocarbons (PAHs) in environmental matrices  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs) and some of their derivatives represent a class of important environmental pollutants possessing a high mutagenic and carcinogenic potential as proven by in vitro experiments with various animal species using different modes of application and in vitro experiments using tissue homogenates, cells in culture and subcellular fractions as well [1,2].PAHs are ubiquitous in the environment, although

J. Jacob

1995-01-01

249

Binding of polycyclic aromatic hydrocarbons by humic acids formed during composting  

Microsoft Academic Search

Binding of two model polycyclic aromatic hydrocarbons (PAHs), phenanthrene and pyrene, by humic acids (HAs) isolated from an organic substrate at different stages of composting and a soil was investigated using a batch fluorescence quenching method and the modified Freundlich model. With respect to soil HA, the organic substrate HA fractions were characterized by larger binding affinities for both phenanthrene

César Plaza; Baoshan Xing; José M. Fernández; Nicola Senesi; Alfredo Polo

2009-01-01

250

Phototoxicity of individual polycyclic aromatic hydrocarbons and petroleum to marine invertebrate larvae and juveniles  

Microsoft Academic Search

Phototoxicity resulting from photoactivated polycyclic aromatic hydrocarbons (PAHs) has been reported in the literature for a variety of freshwater organisms. The magnitude of increase in PAH toxicity often exceeds a factor of 100. In the marine environment phototoxicity to marine organisms has not been reported for individual or complex mixtures of PAHs. In this study, larvae and juveniles of the

Marguerite C. Pelletier; Robert M. Burgess; Kay T. Ho; Anne Kuhn; Richard A. McKinney; Stephan A. Ryba

1997-01-01

251

Characterization of polycyclic aromatic compounds in diesel exhaust particulate extract responsible for aryl hydrocarbon receptor activity  

Microsoft Academic Search

Chemical fractions of a model diesel exhaust particulate extract, notably the fraction containing polycyclic aromatic hydrocarbons (PAH) (Fraction II), mono-nitro PAH (Fraction III), and dinitro-PAH (Fraction IV) have been shown to displace binding of 2,3,7,8-tetrachloro[1,6-[3H

Carol D. Soontjens; Kristina Holmberg; Roger N. Westerholm; Joseph J. Rafter

1997-01-01

252

Photoinduced Mechanism of Formation and Growth of Polycyclic Aromatic Hydrocarbons in Low-Temperature  

E-print Network

Photoinduced Mechanism of Formation and Growth of Polycyclic Aromatic Hydrocarbons in Low by a barrierless addition of a cyano (CN) radical, this newly proposed mechanism can even lead to the formation processes of fossil fuels.1-5 Because of the harmful environmental effects attributed to PAHs, which have

Kaiser, Ralf I.

253

Polycyclic Aromatic Hydrocarbons in Agricultural Soils of the Southern Subtropics, China  

Microsoft Academic Search

The contributions of persistent organic pollutants (POPs) from the subtropical regions of China to pollution of the global environment have been paid great attention; however, little is known about the state of POPs in agricultural ecosystems within these regions of China. This study primarily revealed the state of the contamination and distribution of polycyclic aromatic hydrocarbons (PAH) in agricultural soils

Rong HAO; Hong-Fu WAN; Yan-Tun SONG; Hong JIANG; Shao-Lin PENG

2007-01-01

254

Polycyclic Aromatic Hydrocarbon-Induced Cytotoxicity in Cultured Rat Sertoli Cells Involves Differential Apoptotic Response  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous and persistent environmental contami- nants. Some PAHs are carcinogens and may affect the male reproductive system. Therefore, we exposed cultured rat Sertoli cells to a variety of PAHs to determine possible direct toxic effects on the cells of the seminiferous epithelium. Sertoli cells were chosen because they support germ cell development and maintain spermatogenesis.

Samir S. Raychoudhury; Dana Kubinski

2002-01-01

255

Immunological disorders associated with polychlorinated biphenyls and related halogenated aromatic hydrocarbon compounds  

USGS Publications Warehouse

This review characterizes immunological disorders in fish associated with the widespread environmental contaminants, polychlorinated biphenyls (PCBs), and related halogenated aromatic hydrocarbons (HAHs). Special attention is devoted to comparing the sensitivity of fish species, identifying sensitive immunological endpoints and postulating mechanisms of action.

Noguchi, G.E.

1998-01-01

256

SOLAR RADIATION DOSE AND PHOTOTOXICITY OF POLYCYCLIC AROMATIC HYDROCARBONS: A CASE STUDY  

EPA Science Inventory

The toxicity of polycyclic aromatic hydrocarbons increases by as much as three orders of magnitude in the presence of solar radiation. The risk of this photoactive toxicity is thus based on both tissue concentrations of potentially photo activated compounds and the levels of subs...

257

FATES AND BIOLOGICAL EFFECTS OF POLYCYCLIC AROMATIC HYDROCARBONS IN AQUATIC SYSTEMS  

EPA Science Inventory

This research project was conducted to test the hypothesis that fates of polycyclic aromatic hydrocarbons (PAH) in ecosystems can be predicted by mechanistic simulation models based on easily measured properties of the compounds in this homologous series. To accomplish this goal ...

258

Diversity of ndo Genes in Mangrove Sediments Exposed to Different Sources of Polycyclic Aromatic Hydrocarbon Pollution  

Microsoft Academic Search

Polycyclic aromatic hydrocarbon (PAH) pollutants originating from oil spills and wood and fuel combustion are pollutants which are among the major threats to mangrove ecosystems. In this study, the composition and relative abundance in the sediment bacterial communities of naphthalene dioxygenase (ndo) genes which are important for bacterial adaptation to environmental PAH contamination were investigated. Three urban mangrove sites which

Newton C. Marcial Gomes; Ludmila R. Borges; Rodolfo Paranhos; Fernando N. Pinto; Ellen Krogerrecklenfort; Leda C. S. Mendonca-Hagler; Kornelia Smalla

2007-01-01

259

EXTRACTION AND DETERMINATION OF SELECTED POLYCYCLIC AROMATIC HYDROCARBONS IN PLANT TISSUES  

EPA Science Inventory

A procedure has been developed for analysis of plant material for polycyclic aromatic hydrocarbons (PAHs). Sonication is used to extract the PAHs from homogenized plant material into acetonitrile and then the PAHs are partitioned into pentane. The pentane extract is fractionated ...

260

Polycyclic Aromatic Hydrocarbons Present in Cigarette Smoke Cause Bone Loss in an Ovariectomized Rat Model  

E-print Network

Polycyclic Aromatic Hydrocarbons Present in Cigarette Smoke Cause Bone Loss in an Ovariectomized of epidemiological studies have suggested that cigarette smoking is a risk factor for osteoporosis. Benzo- (a in the tar fraction of cigarette smoke, as well as in car exhaust and furnace gases. We hypothesized that Ba

Waldman, Stephen D.

261

Role of nutrients in the utilization of polycyclic aromatic hydrocarbons by halotolerant bacterial strain  

Microsoft Academic Search

A halotolerant bacterial strain VA1 isolated from marine environment was studied for its ability to utilize polycylic aromatic hydrocarbons (PAHs) under saline condition. Anthracene and pyrene were used as representatives for the utilization of PAH by the bacterial strain. Glucose and sodium citrate were used as additional carbon sources to enhance the PAH utilization. The strain VA1 was able to

Pugazhendi Arulazhagan; Namsivayam Vasudevan

2011-01-01

262

Polycyclic aromatic hydrocarbon hazards to fish, wildlife, and invertebrates: a synoptic review  

Microsoft Academic Search

The report synthesizes technical literature on ecological and toxicological aspects of polycyclic aromatic hydrocarbons (PAH) in the environment, with special reference to fisheries and wildlife resources. Subtopics include: chemical properties, sources, and fate; background concentrations in biological and nonbiological samples; toxic and sublethal effects of PAH to flora and fauna; proposed criteria and research needs for the protection of sensitive,

Ronald Eisler

1987-01-01

263

HIGH PURITY PNA HYDROCARBONS AND OTHER AROMATIC COMPOUNDS. SYNTHESIS AND PURIFICATION  

EPA Science Inventory

The synthesis and/or purification of a group of polynuclear aromatic (PNA) hydrocarbons, commonly found as pollutants in the environment, are described. The steps used in a given synthesis, the experiments carried out, and a presentation of some instrumental data obtained in esta...

264

Characterization of subsurface polycyclic aromatic hydrocarbons at the Deepwater Horizon site  

Microsoft Academic Search

Here, we report the initial observations of distributions of polycyclic aromatic hydrocarbons (PAH) in subsurface waters near the Deepwater Horizon oil well site (also referred to as the Macondo, Mississippi Canyon Block 252 or MC252 well). Profiles of in situ fluorescence and beam attenuation conducted during 9-16 May 2010 were characterized by distinct peaks at depths greater than 1000 m,

Arne-R. Diercks; Raymond C. Highsmith; Vernon L. Asper; DongJoo Joung; Zhengzhen Zhou; Laodong Guo; Alan M. Shiller; Samantha B. Joye; Andreas P. Teske; Norman Guinasso; Terry L. Wade; Steven E. Lohrenz

2010-01-01

265

REMOVAL OF POLYNUCLEAR AROMATIC HYDROCARBONS FROM PRIMARY ALUMINUM AIR POLLUTION CONTROL SCRUBBER WASTEWATER  

EPA Science Inventory

A pilot-scale study was conducted at a primary aluminum plant to evaluate the removal of benzo(a)pyrene and other polynuclear aromatic hydrocarbons (PAH's) from potline scrubber wastewater. Specific objectives included determining the need for granular activated carbon to remove ...

266

POLYCYCLIC AROMATIC HYDROCARBON FORMATION IN OPPOSED FLOW DIFFUSION FLAMES OF ETHANE. (R825412)  

EPA Science Inventory

Abstract The effect of fuel-side carbon density on the levels of polycyclic aromatic hydrocarbon (PAH) formation in atmospheric pressure, opposed flow, ethane diffusion flames has been studied using heated micro-probe sampling and gas chromatography/mass spectrometry (...

267

CALCULATION OF ELECTRON AFFINITIES OF POLYCYCLIC AROMATIC HYDROCARBONS AND SOVATION ENERGIES OF THEIR ANIONS  

EPA Science Inventory

Electron affinities (EAs) and free energies for electron attachment have been calculated for 42 polynuclear aromatic hydrocarbons and related molecules by a variety of theoretical models, including Koopmans' theorem methods and the L1E method from differences in energy between th...

268

EVALUATION OF SAMPLING AND ANALYTICAL METHODS FOR NICOTINE AND POLYNUCLEAR AROMATIC HYDROCARBON IN INDOOR AIR  

EPA Science Inventory

The objective of the project was to evaluate a potential collection medium, XAD-4 resin, for collecting nicotine and polynuclear aromatic hydrocarbon (PAH) and to determine whether one collection system and one analytical method will allow quantification of both compound classes ...

269

Occurrence of Polycyclic Aromatic Hydrocarbons in Artisanal Palmero Cheese Smoked with Two Types of Vegetable Matter  

Microsoft Academic Search

Palmero cheese is a fresh smoked cheese from the Isle of Palma (Canary Islands), manufactured with goat's milk. To guarantee its safety, the occurrence of polycy- clic aromatic hydrocarbons (PAH) in artisanal Palmero cheese smoked with 2 types of vegetable matter (almond shells and dry prickly pear) was studied. The determi- nation of PAH includes extraction and clean-up steps, followed

M. D. Guillén; G. Palencia; P. Sopelana; M. L. Ibargoitia

2007-01-01

270

Anaerobic degradation of five polycyclic aromatic hydrocarbons from river sediment in Taiwan  

Microsoft Academic Search

This study investigated the anaerobic degradation of five polycyclic aromatic hydrocarbons (PAHs) from Erren River sediment in southern Taiwan. The degradation rates of PAH were in the order: acenaphthene > fluorene > phenanthrene > anthracene > pyrene. The degradation rate was enhanced when the five compounds were present simultaneously in river sediment. Comparison of the PAH degradation rates under three

Shaw Y. Yuan; Bea V. Chang

2007-01-01

271

Contamination and potential biodegradation of polycyclic aromatic hydrocarbons in mangrove sediments of Xiamen, China  

Microsoft Academic Search

Five stations were established in the Fenglin mangrove area of Xiamen, China to determine the concentrations of polycyclic aromatic hydrocarbons (PAHs) and the numbers of PAH-degrading bacteria in surface sediments. Assessing the biodegradation potential of indigenous microorganisms and isolating the high molecule weight (HMW)–PAH degrading bacteria was also one of the aims of this work. The results showed that the

Yun Tian; Yuan-rong Luo; Tian-ling Zheng; Li-zhe Cai; Xiao-xing Cao; Chong-ling Yan

2008-01-01

272

Degradation of polycyclic aromatic hydrocarbons by a bacterial consortium enriched from mangrove sediments  

Microsoft Academic Search

The biodegradability of a polycyclic aromatic hydrocarbons (PAHs) mixture consisted of fluorene (Fl), phenanthrene (Phe) and pyrene (Pyr) by a bacterial consortium enriched from mangrove sediments under sediment-free and sediment slurry conditions was investigated. The enriched consortium made up of three bacterial strains, namely Rhodococcus sp., Acinetobacter sp. and Pseudomonas sp., had a good PAH degradation capability with 100% degradation

S. H. Yu; L. Ke; Y. S. Wong; N. F. Y. Tam

2005-01-01

273

Removal of polycyclic aromatic hydrocarbons (PAHs) from sewage sludge by anaerobic degradation  

E-print Network

Removal of polycyclic aromatic hydrocarbons (PAHs) from sewage sludge by anaerobic degradation N, terminate in the sludge, and can be released to the environment if land spreading is used. PAH degradation factors of anaerobic PAH degradation by evaluating thermodynamic feasibility of degradation, assessing

274

Enumeration and phylogenetic analysis of polycyclic aromatic hydrocarbon-degrading marine bacteria from Puget Sound sediments  

SciTech Connect

Polycyclic aromatic hydrocarbons (PAHs) are primarily released into the environment through anthropomorphic sources. PAH degradation has been known to occur in marine sediments. This paper describes the enumeration, isolation, and preliminary characterization of PAH-degrading strains from Puget Sound sediments. 38 refs., 3 figs., 3 tabs.

Geiselbrecht, A.D.; Herwig, R.P.; Deming, J.W.; Staley, J.T. [Univ. of Washington, Seattle, WA (United States)

1996-09-01

275

Sampling precautions for the measurement of nitrated polycyclic aromatic hydrocarbons in ambient air  

E-print Network

oxidant scrubber to prevent chemical degradation of PAHs and derivatives during their sampling. Moreover of polycyclic aromatic hydrocarbons (PAHs) and of their oxidation products, such as nitrated and oxygenated PAHs presents a comparison of particulate PAH, OPAH and NPAH concentrations determined with two different

Paris-Sud XI, Université de

276

Characterization of polycyclic aromatic compounds in diesel exhaust particulate extract responsible for aryl hydrocarbon receptor activity  

NASA Astrophysics Data System (ADS)

Chemical fractions of a model diesel exhaust particulate extract, notably the fraction containing polycyclic aromatic hydrocarbons (PAH) (Fraction II), mono-nitro PAH (Fraction III), and dinitro-PAH (Fraction IV) have been shown to displace binding of 2,3,7,8-tetrachloro[1,6-[ 3H

Soontjens, Carol D.; Holmberg, Kristina; Westerholm, Roger N.; Rafter, Joseph J.

277

Concentration of Polycyclic Aromatic Hydrocarbons (PAHs) in Moss (Hypnum cupressiforme) from Hungary  

Microsoft Academic Search

Mosses of the species Hypnum cupressiforme were collected from different parts of Hungary to investigate the air quality of the region. The concentrations of polycyclic aromatic hydrocarbons (PAHs) in species were determined. Low molecular weight PAHs (up to three ring compounds) contribute more than 99% to the concentrations of PAHs in Moss samples. The pattern of PAHs suggests local sources

Imre Olivér Kozák; Melinda Kozák; Jen? Fekete; Virender K. Sharma

2003-01-01

278

Prediction of Solid Polycyclic Aromatic Hydrocarbons Solubility in Water with the NRTL-PR Model  

E-print Network

Prediction of Solid Polycyclic Aromatic Hydrocarbons Solubility in Water with the NRTL-PR Model conditions. The aim of this work is to explore the capability of the NRTL-PR model to predict the solubility consider the prediction of the solid solubility of PAH in water, by fitting group parameters either only

Paris-Sud XI, Université de

279

Occurrence and Phylogenetic Diversity of Sphingomonas Strains in Soils Contaminated with Polycyclic Aromatic Hydrocarbons  

Microsoft Academic Search

Bacterial strains of the genus Sphingomonas are often isolated from contaminated soils for their ability to use polycyclic aromatic hydrocarbons (PAH) as the sole source of carbon and energy. The direct detection of Sphingomonas strains in contaminated soils, either indigenous or inoculated, is, as such, of interest for bioremediation purposes. In this study, a culture-independent PCR-based detection method using specific

Natalie M. E. J. Leys; Annemie Ryngaert; Leen Bastiaens; Willy Verstraete; Eva M. Top; Dirk Springael

2004-01-01

280

Theoretical reactivity (carcinogenicity) indices for selected aza?polycyclic aromatic hydrocarbons  

Microsoft Academic Search

Huckel molecular orbital calculations and application of Seybold?Smith reactivity theory suggests an explanation for the different carcinogenic potencies observed among selected aza?polycyclic aromatic hydrocarbons in terms of the tendencies of these compounds to undergo specific metabolic activating reactions. Theoretical reactivity indices representing these reactions correlate with the carcinogenic activities of these environmental pollutants and can be used as an estimate

David S. Soriano; Jon A. Draeger; Donald A. Robbins; Victoria Soriano

1989-01-01

281

Isomeric differentiation of polycyclic aromatic hydrocarbons using silver nitrate reactive desorption electrospray ionization  

E-print Network

Isomeric differentiation of polycyclic aromatic hydrocarbons using silver nitrate reactive industrial activities.[1] Because of their effect as carcinogens,[2] PAHs are included in the US the surface which become gas-phase ions upon desolvation.[4,5] Reactive DESI is a new development in DESI

Zare, Richard N.

282

Assessment of Exposure to Polycyclic Aromatic Hydrocarbons (PAH) in Italian Asphalt Workers  

Microsoft Academic Search

The purpose of the work was the assessment of exposure to Polycyclic Aromatic Hydrocarbons (PAH), a family of ubiquitous pollutants of which some are carcinogens, in 100 Italian asphalt workers (exposed to bitumen fumes and diesel exhausts) and in a reference group of 47 ground construction operators (exposed only to diesel exhausts, reference group). The protocol included interview via questionnaires,

Piero Emanuele Cirla; Irene Martinotti; Marina Buratti; Silvia Fustinoni; Laura Campo; Epifania Zito; Enzandrea Prandi; Omar Longhi; Domenico Cavallo; Vito Foà

2007-01-01

283

Increased Capacity for Polycyclic Aromatic Hydrocarbon Mineralization in Bioirrigated Coastal Marine Sediments  

Microsoft Academic Search

Bioirrigation of marine sediments by benthic infauna has the potential to increase both the rate and depth of bacterial mineralization of polycyclic aromatic hydrocarbons (PAHs) by recirculating oxygenated bottom water into sediment burrows. Rates of heterotrophic bacterial production and mineralization of PAHs (naphthalene, phenanthrene, and fluoranthene) were measured in sections of sediment cores sampled from stations in San Diego Bay.

Michael T. Montgomery; Christopher L. Osburn; Yoko Furukawa; Joris M. Gieskes

2008-01-01

284

Aliphatic/aromatic and chlorinated hydrocarbon emissions control with a fixed-bed catalytic oxidizer  

SciTech Connect

A fixed-bed catalytic oxidation system with caustic scrubbing was used to cost-effectively control emissions of aliphatic/aromatic and chlorinated hydrocarbons during soil remediation at McClellan Air Force Base (McAFB), Sacramento, California. Soil gas extracted by a soil vapor extraction (SVE) system contained trichloroethane (TCE), 1,1,1-trichloroethane (TCA), cis-1,2-dichloroethene (DCE), methylene chloride, and a variety of petroleum-based hydrocarbons. Catalytic oxidative treatment of these chlorinated hydrocarbons creates acid gases (hydrochloric acid [HCl] and hydrofluoric acid [HF]), which were removed in a caustic scrubber. Testing for hydrocarbon destruction and removal efficiency (DRE), acid gas scrubbing efficiency, dioxin/furan formation, and criteria pollutant emission rates (process byproducts) was conducted. Over 175,000 pounds of hydrocarbons have been treated/biodegraded in a nine-month operating period.

Singh, S. [URS Consultants, Inc., Sacramento, CA (United States); Brook, L. [URS Consultants, Inc., Denver, CO (United States); Shirley, R.

1996-12-31

285

[Distribution of polycyclic aromatic hydrocarbons in soil profiles in southeast suburb of Beijing wastewater irrigation area].  

PubMed

3 borehole profiles samples were collected using Eijkelkamp soil sampler from the wastewater irrigation area of Beijing Southeast suburb. The soil samples were collected from surface to 5.5 m underground every 0.5 m. Physical-chemical properties of the samples such as clay content, total amount of clay minerals, cation exchange capacity (CEC), total organic compounds (TOC), etc. were analyzed. 16 polycyclic aromatic hydrocarbons (PAHs) defined by the U.S. EPA were also analyzed with gas chromatography-mass spectrometry (GC-MS). Results show that 14 PAHs were detected in the surface soil samples. The concentrations of PAHs range from 4 microg/kg to 428 microg/kg. Under the surface,both species and concentrations of PAHs in soil samples drop very fast. Only 2 rings and 3 rings PAHs were detected, which were naphthalene,phenanthrene, fluorene, acenaphthylene, acenaphthene, and fluoranthene. Clay content, total amount of clay minerals, CEC and TOC have significant correlations at 0.05 level between each other. Under the surface, clay contents also have a relationship with low-rings PAHs concentration. Where the layers have higher clay contents,the PAHs have higher concentrations. The contents of PAHs changing along the profiles also show that, low-rings PAHs are easier to migrate than high-rings PAHs. The sequence of the migration capabilities of low-ring PAHs is acenaphthene > fluorene > naphthalene > phenanthrene > acenaphthylene > fluoranthene. However, high-ring PAHs were only detected in surface soil samples. That means low-rings PAHs can reach the deep layers of the vertical profiles under long-term wastewater irrigation. Therefore, the shallow groundwater has the possibility to be contaminated. PMID:19558087

He, Jiang-Tao; Jin, Ai-Fang; Chen, Su-Nuan; Wei, Yong-Xia

2009-05-15

286

Quantitative analysis of polynuclear aromatic hydrocarbons in liquid fuels. Final report Oct 76-Oct 78  

SciTech Connect

Polynuclear aromatic hydrocarbons (PNAs), formed in combustion processes with liquid hydrocarbon fuels, contribute to mobile source exhaust emissions. Because correlation between PNA levels in automobile exhaust and pre-existent PNAs in fuel has been demonstrated in previous work, a quantitative analysis of 12 individual polynuclear aromatic hydrocarbons present in various aircraft turbine, diesel, and gasoline test fuels was determined in this project. The PNAs included phenanthrene, anthracene, fluoranthene, pyrene, benzo(a)anthracene, chrysene, triphenylene, benzo(a)pyrene, benzo(e)pyrene, benzo(g,h,i)perylene, coronene and anthanthrene. The fuel samples were analyzed by combined gas chromatography/mass spectrometry (GC-MS) after a preliminary isolation/concentration scheme. Liquid crystal chromatographic columns were employed to resolve isomeric PNAs. The results indicated that anthanthrene and coronene were not detected in any of the samples analyzed.

Parr, J.L.

1980-04-01

287

Characterization of polycyclic aromatic hydrocarbons and metals in ashes released from a forest fire  

NASA Astrophysics Data System (ADS)

Wildfires have become a permanent source of environmental and societal concerns. Whilst the impacts of wildfire on hydrological and erosion processes are well documented, the stocks and export of polycyclic aromatic hydrocarbons (PAHs) and heavy metals have received considerably less research attention. The ashes produced by wildfires, which include polluting substances such as PAHs and metals, are subject to transport processes by wind and especially by overland flow and water infiltrating into the soil and possibly reaching ground water bodies. In the framework of the FIRECNUTS project, we are studying the stocks of PAHs and selected metals in recently burnt forest stands in north-central Portugal, and their subsequent export by overland flow. The present work, however, will focus on the stocks in the ashes, both immediately after wildfire and three months later. These ashes were collected at two burnt slopes with contrasting forest types, i.e. a eucalypt and a maritime pine stand, the two pre-dominant forest types in the study region. The sixteen PAHs identified by US EPA as priority contaminants were analysed by gas chromatograph, after extraction and column clean up. The contents of vanadium (V), chromium (Cr), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd) and lead (Pb) were analysed by inductively coupled plasma- mass spectrometry (ICP-MS), after an acid digestion, while mercury (Hg) was analysed by pyrolysis atomic absorption spectrometry with gold amalgamation. The total concentration of PAHs immediately after the wildfire ranged from 314 ng/g dry weight in the maritime pine stand to 597 ng/g dry weight in the eucalypt stand. Three months later, the total concentration has decreased with 33% in the pine stand but only half (16%) in the eucalypt stand. The composition the PAHs by ring size was dominated by three-rings PAHs. This was true for all samples. The concentrations of various metals differed for the two sampling occasions but not in straightforward manners. Some metals (Co, Ni, Cu, Zn, Cd, Pb and Hg) revealed higher contents immediately after the fire, whereas others (V, Cr and As) did three months later. The present results underline the importance of furthering the knowledge about contamination of soil and water by ashes from wildfires and the associated risks in terms of ecotoxicological effects, both in-situ and in downstream aquatic systems. Keywords: Polycyclic aromatic hydrocarbons (PAH); heavy metals; stocks; ash; wildfires

Campos, I.; Abrantes, N.; Pereira, P.; Vale, C.; Ferreira, A.; Keizer, J. J.

2012-04-01

288

HETEROGENEOUS PHOTOCATALYTIC DECOMPOSITION OF POLY- AROMATIC HYDROCARBONS OVER TITANIUM DIOXIDE  

EPA Science Inventory

The photocatalytic degradation of a mixture of 16 polyaromatic hydrocarbons (PAHs) was investigated in aqueous suspensions of high surface area TiO2 illuminated with 310?380 nm ultraviolet light. Triethylamine was utilized for extraction of PAH compounds from motor oil...

289

Aromatic Hydrocarbons, Diamonds, and Fullerenes in Interstellar Space Puzzles to be Solved by Laboratory and Theoretical Astrochemistry  

E-print Network

New research is presented, and previous research is reviewed, on the emission and absorption of interstellar aromatic hydrocarbons. Emission from aromatic hydrocarbons dominate the mid-infrared emission of many galaxies, including our own Milky Way galaxy. Only recently have aromatic hydrocarbons been observed in absorption in the interstellar medium, along lines of sight with high column densities of interstellar gas and dust. Much work on interstellar aromatics has been done, with astronomical observations and laboratory and theoretical astrochemistry. In many cases the predictions of laboratory and theoretical work are confirmed by astronomical observations, but in other cases clear discrepancies exist which provide problems to be solved by a combination of astronomical observations, laboratory studies, and theoretical studies. The emphasis of this paper will be on current outstanding puzzles concerning aromatic hydrocarbons which require further laboratory and theoretical astrochemistry to resolve. This p...

Sellgren, K

2000-01-01

290

Emissions of polycyclic aromatic hydrocarbons from thermal pre-treatment of waste hydrodesulfurization catalysts.  

PubMed

Despite increasing environmental concerns and stringent limitations on the sulfur content in fuels, many waste hydrodesulfurization (HDS) catalysts containing Co, Mo, Ni and V are generated in the petroleum refining process. To recover valuable metals in the waste HDS catalysts via hydrometallurgy, thermal treatment is usually performed first to remove contaminants (residual oil, carbon and sulfur) present on the surface of catalysts. In this study, the mass partitions of polycyclic aromatic hydrocarbons (PAHs) in different media (aqueous, particulate and gaseous) were quantified in order to determine the efficiency of three different air pollution control devices, cooling unit, filter and glass cartridge, on PAH removal. An afterburner and two furnace temperatures were used to observe the effect on the PAH contents of the treated residues. Results show that total-PAH content in treated residues decreased with the pyrolysis temperature of the primary furnace, while those generated in flue gases were destroyed by the afterburner at an efficiency of approximately 95%. In addition, the thermal process converts high molecular weight PAHs to low molecular weight PAHs, and the afterburner temperature involved (1200 degrees C) was high enough to prohibit the generation of high molecular weight PAHs (HM-PAHs), leading to the domination of low molecular weight PAHs (LM-PAHs) in flue gases, while treated residues were dominated by HM-PAHs. Finally, information on metal contents and their concentrations in the Toxicity Characteristic Leaching Procedure in waste HDS catalyst and thermal treated residues are examined as an index of the potential for metal recovery. PMID:17531290

Lai, Yi-Chieh; Lee, Wen-Jhy; Huang, Kuo-Lin; Huang, Hong-Hsin

2007-09-01

291

Aliphatic and polycyclic aromatic hydrocarbons in Black Sea sediments  

Microsoft Academic Search

Concentrations of aliphatic hydrocarbons (AHC) in sediments of the Black Sea ranged from 153,000 ng g?1 dw near the mouth of the Danube River to about 10,000 ng g?1 dw in abyssal plain sediments. Compound distributions were dominated by long-chain n-alkanes except at the Danube station where a significant petrogenic component with an unresolved complex mixture was also present. Polycyclic

Stuart G. Wakeham

1996-01-01

292

Metal-mediated making and breaking of carbon-carbon bonds in aromatic hydrocarbons  

SciTech Connect

Because of the thermodynamic stability of the aromatic sextet, the tendency of many unsaturated compounds, such as alkenes and alkynes, to form aromatic systems is readily comprehensible. Thus, the Reppe cyclotrimerization of alkynes to benzenes by agency of (Ph/sub 3/P)/sub 2/(CO)/sub 2/Ni is no cause for wonder. But the similar cyclotetramerization of certain alkynes to the non-aromatic cyclooctatetraenes by nickel(0) or nickel (II) cyanide must, in contrast, be astonishing. Yet a closer study of the behavior of both nickel(0) complexes and of alkali metals reveals that both metals are able to disrupt aromatic systems almost as readily as they can induce their formation. Basic both to the formation and the disruption of aromatics by low-valent metal reagents M/sup 0/ appears to be the possibility of electron transfer from the metal to a sufficiently low-lying antibonding molecular orbital of the reagent hydrocarbon. This paper analyzes the formation and chemical behavior of intermediates with examples drawn from reactions of lithium and of nickel. Emphasis is on the formation of new C-C sigma-bonds in aromatic systems with the preliminary disruption of C-C pi-bonds. Such processes will be shown to hold great promise for the rational construction of polycyclic aromatics.

Eisch, J.J.

1986-09-01

293

Historical changes in the concentrations of polycyclic aromatic hydrocarbons (PAHs) in Lake Peipsi sediments.  

PubMed

The distribution of 11 individual polycyclic aromatic hydrocarbons (PAHs) was analysed in a (210)Pb dated sediment core from the deepest area of Lake Peipsi and in four surface sediment samples taken from littoral areas. According to the concentrations in the core three groups of PAHs may be distinguished: (1) relatively stable concentrations of PAHs within the whole studied time interval; (2) very low concentrations in sediments accumulated before intensive anthropogenic impact (from 19th century up to the 1920s) following a slight increase and (3) an overall increase in PAH concentrations since the 1920s up to the present. Comprehensive analysis of PAHs in the core and monitoring data obtained in the 1980s together with the lithology of sediments show that an increase of anthropogenically induced PAHs correlates well with the history of fuel consumption in Estonia and speaks about atmospheric long-distance transport of PAHs. The continuous increase of PAH concentrations since the 1920s do not support the earlier hypothesis about the dominating impact of the oil shale fired power plants near the lake, because their emissions decreased significantly in the 1990s. The concentration of PAHs in the deep lake core sample correlates well with the content of organic matter, indicating absorption and co-precipitation with plankton in the sediment. PMID:18270801

Punning, Jaan-Mati; Terasmaa, Jaanus; Vaasma, Tiit; Kapanen, Galina

2008-09-01

294

Removal of polycyclic aromatic hydrocarbons (PAHs) from industrial sludges in the ambient air conditions: automotive industry.  

PubMed

Removal of polycyclic aromatic hydrocarbons (PAHs) existed in automotive industry treatment sludge was examined by considering the effects of temperature, UV, titanium dioxide (TiO2) and diethyl amine (DEA) in different dosages (i.e., 5% and 20%) in this study. Application of TiO2 and DEA to the sludge samples in ambient environment was studied. Ten PAH (?10 PAH) compounds were targeted and their average value in the sludge was found to be 4480 ± 1450 ng/g dry matter (DM). Total PAH content of the sludge was reduced by 25% in the ambient air environment. Meteorological conditions, atmospheric deposition, evaporation and sunlight irradiation played an effective role in the variations in PAH levels during the tests carried out in ambient air environment. Moreover, it was observed that when the ring numbers of PAHs increased, their removal rates also increased. Total PAH level did not change with the addition of 5% DEA and only 10% decreased with 5% TiO2 addition. PAH removal ratios were 8% and 32% when DEA (20%) and TiO2 (20%) were added, respectively. It was concluded that DEA was a weak photo-sensitizer yet TiO2 was effective only at 20% dosage. PMID:23485234

Karaca, Gizem; Tasdemir, Yucel

2013-01-01

295

Polycyclic aromatic hydrocarbons in wastewater, WWTPs effluents and in the recipient waters of Beijing, China.  

PubMed

In this study, surface water samples from the Wenyu River and the North Canal, effluent from major wastewater treatment plants (WWTPs) in Beijing, and wastewater from open sewers that discharge directly into the river system were collected and analyzed for 16 priority USEPA polycyclic aromatic hydrocarbons (PAHs). Concentrations of these 16 PAHs ranged from 193 to 1790 ng/L in river surface waters, 245 to 404 ng/L in WWTP effluents, and 431 to 2860 ng/L in the wastewater from the small sewers. The WWTP effluent was the main contributor of dissolved PAHs to the river, while wastewater from the small sewers contributed both dissolved and suspended particulate matter-associated PAH to the river as indicated by the high dissolved organic carbon and suspended particulate matter contents in the wastewater. Although the flow from each open sewer was small, a PAH discharge as high as 44 kg/year could occur into the river from these types of sewers. This amount was equivalent to about 22 % of the PAH loads discharged into the North Canal downstream from Beijing, whereas the remainder was mainly released by the major WWTPs in Beijing. PMID:23292225

Qi, Weixiao; Liu, Huijuan; Pernet-Coudrier, Benoît; Qu, Jiuhui

2013-06-01

296

Cancer risk assessments of Hong Kong soils contaminated by polycyclic aromatic hydrocarbons.  

PubMed

The aim of this study was to evaluate soils from 12 different land use types on human cancer risks, with the main focus being on human cancer risks related to polycyclic aromatic hydrocarbons (PAHs). Fifty-five locations were selected to represent 12 different types of land use (electronic waste dismantling workshop (EW (DW)); open burning site (OBS); car dismantling workshop (CDW) etc.). The total concentrations of 16 PAHs in terms of total burden and their bioaccessibility were analysed using GC/MS. The PAHs concentrations were subsequently used to establish cancer risks in humans via three exposure pathways, namely, accident ingestion of soil, dermal contact soil and inhalation of soil particles. When the 95th centile values of total PAH concentrations were used to derive ingestion and dermal cancer risk probabilities on humans, the CDW land use type indicated a moderate potential for cancerous development (244 × 10(-6) and 209 × 10(-6), respectively). Bioaccessible PAHs content in soil samples from CDW (3.60 × 10(-6)) were also classified as low cancer risk. CDW soil possessed a higher carcinogenic risk based on PAH concentrations. Bioremediation is recommended to treat the contaminated soil. PMID:23465409

Man, Yu Bon; Kang, Yuan; Wang, Hong Sheng; Lau, Winifred; Li, Hui; Sun, Xiao Lin; Giesy, John P; Chow, Ka Lai; Wong, Ming Hung

2013-10-15

297

Spatial Characterization of Polycyclic Aromatic Hydrocarbons in 2008 TC3 Samples  

NASA Astrophysics Data System (ADS)

Hassan Sabbah1, Amy L. Morrow1, Richard N. Zare1 and Petrus Jenniskens2 1Stanford University, Stanford, California 94305, 2 SETI Institute, Carl Sagan Center, 515 North Whisman Road, Mountain View, California 94043, USA. In October 2006 a small asteroid (2-3 meters) was observed in outer space. On October 7, 2008, it entered the Earth's atmosphere creating a fireball over Northern Sudan. Some 280 meteorites were collected by the University of Khartoum. In order to explore the existence of organic materials, specifically polycyclic aromatic hydrocarbons (PAHs), we applied two-step laser desorption laser ionization mass spectrometry (L2MS) to some selected fragments. This technique consists of desorbing with a pulsed infrared laser beam the solid materials into a gaseous phase with no fragmentation followed by resonance enhanced multiphoton ionization to analyze the PAH content. L2MS was already applied to an array of extraterrestrial objects including interplanetary dust particles IDPs, carbonaceous chondrites and comet coma particles. Moreover, spatial resolution of PAHs in 2008 TC3 samples was achieved to explore the heterogeneity within individual fragments. The results of these studies and their contribution to understanding the formation of this asteroid will be discussed.

Sabbah, Hassan; Morrow, A.; Zare, R. N.; Jenniskens, P.

2009-09-01

298

Rinodina sophodes (Ach.) Massal.: a bioaccumulator of polycyclic aromatic hydrocarbons (PAHs) in Kanpur City, India.  

PubMed

The aim of this study is to determine the possibility of using Rinodina sophodes (Ach.) Massal., a crustose lichen as polycyclic aromatic hydrocarbons (PAHs) bioaccumulator for evaluation of atmospheric pollution in tropical areas of India, where few species of lichens are able to grow. PAHs were identified, quantified and compared to evaluate the potential utility of R. sophodes. The limit of detection for different PAHs was found to be 0.008-0.050 ?g g(?-?1). The total PAHs in different sites were ranged between 0.189 ± 0.029 and 0.494 ± 0.105 ?g g(?-?1). The major sources of PAHs were combustion of organic materials, traffic and vehicular exhaust (diesel and gasoline engine). Significantly higher concentration of acenaphthylene and phenanthrene indicates road traffic as major source of PAH pollution in the city. Two-way ANOVA also confirms that all PAHs content showed significant differences between all sampling sites (P 1%). This study establishes the utility of R. sophodes in monitoring the PAHs accumulation potentiality for development of effective tool and explores the most potential traits resistant to the hazardous environmental conditions in the tropical regions of north India, where no such other effective way of biomonitoring is known so far. PMID:21465135

Satya; Upreti, Dalip K; Patel, D K

2012-01-01

299

Environmental tobacco smoke as a source of polycyclic aromatic hydrocarbons in settled household dust.  

PubMed

Environmental tobacco smoke is a major contributor to indoor air pollution. Dust and surfaces may remain contaminated long after active smoking has ceased (called 'thirdhand' smoke). Polycyclic aromatic hydrocarbons (PAHs) are known carcinogenic components of tobacco smoke found in settled house dust (SHD). We investigated whether tobacco smoke is a source of PAHs in SHD. House dust was collected from 132 homes in urban areas of Southern California. Total PAHs were significantly higher in smoker homes than nonsmoker homes (by concentration: 990 ng/g vs 756 ng/g, p = 0.025; by loading: 1650 ng/m(2) vs 796 ng/m(2), p = 0.012). We also found significant linear correlations between nicotine and total PAH levels in SHD (concentration, R(2) = 0.105; loading, R(2) = 0.385). Dust collected per square meter (g/m(2)) was significantly greater in smoker homes and might dilute PAH concentration in SHD inconsistently. Therefore, dust PAH loading (ng PAH/m(2)) is a better indicator of PAH content in SHD. House dust PAH loadings in the bedroom and living room in the same home were significantly correlated (R(2) = 0.468, p < 0.001) suggesting PAHs are distributed by tobacco smoke throughout a home. In conclusion, tobacco smoke is a source of PAHs in SHD, and tobacco smoke generated PAHs are a component of thirdhand smoke. PMID:22397504

Hoh, Eunha; Hunt, Richard N; Quintana, Penelope J E; Zakarian, Joy M; Chatfield, Dale A; Wittry, Beth C; Rodriguez, Edgar; Matt, Georg E

2012-04-01

300

Polycyclic aromatic hydrocarbons in commercial squids from different geographical origins: levels and risks for human consumption.  

PubMed

The concentrations of 18 polycyclic aromatic hydrocarbons (PAHs) were determined in five commercially valuable squid species from different geographical origins (Atlantic, Indic and Pacific Oceans). Out of the 18 quantified PAHs (the 16 PAHs considered by US EPA as priority pollutants, dibenzo(a,l)pyrene and benzo(j)fluoranthene) only dibenz(a,h)anthracene was not detected. The total concentrations of PAHs varied by a factor of more than 100-fold, from 0.22 (Loligo gahi) to 60.9 ?g/kg ww (Loligo reynaudii). Intra- and inter-specific variability of PAH levels was statistically assessed. Nine carcinogenic (probable/possible) PAHs accounted for 1% (L. reynaudii) to 26% (Loligo opalescens) of the total PAHs content being the main contributors naphthalene (in Loligo duvaucelii, L. reynaudii and Loligo vulgaris species), chrysene (in L. opalescens) and indeno(1,2,3-cd)pyrene (in L. gahi). PAHs source analysis indicated that four of the five zones of capture of the different squid species are significantly affected by both petrogenic and pyrolytic sources. Assessment of the target carcinogenic risks, established by the US EPA, suggested that L. gahi (Atlantic Ocean) and L. opalescens (from Pacific Ocean) may pose additional risks for consumers, if not eaten in moderation, derived from benzo(a)pyrene ingestion. PMID:23727335

Gomes, Filipa; Oliveira, Marta; Ramalhosa, Maria João; Delerue-Matos, Cristina; Morais, Simone

2013-09-01

301

Degradation and mineralization of the polycyclic aromatic hydrocarbons anthracene and naphthalene in intertidal marine sediments  

SciTech Connect

The degradation of the polynuclear aromatic hydrocarbons (PAHs) anthracene and naphthalene by the microbiota of intertidal sediments was investigated in laboratory studies. No mineralization of either PAH was observed in the absence of oxygen. Both rates and total amounts of PAH mineralization were strongly controlled by oxygen content and temperature of the incubations. Inorganic nitrogen and glucose amendments had minimal effects on PAH mineralization. The rates and total amounts of PAH mineralized were directly related to compound concentration, pre-exposure time, and concentration. Maximum mineralization was observed at the higher concentrations (5 to 100 ..mu..g/g (ppm)) of both PAHs. Optimal acclimation to anthracene and naphthalene (through pre-exposures to the compounds) occurred at the highest acclimation concentration (1,000 ppm). However, acclimation to a single concentration (100 ppm) resulted in initial relative mineralization rates over a range of re-exposure concentrations (1 to 1,000 ppm) being nearly identical. Maximum mineralization of both PAHs occurred after intermediate periods (1 to 2 weeks) of pre-exposure. The fraction of the total heterotrophic population capable of utilizing anthracene or naphthalene as sole carbon source was also greatest after 2 weeks.

Bauer, J.E.; Capone, D.G.

1985-07-01

302

Bioavailability and biotransformation of polycyclic aromatic hydrocarbons in the benthos of coastal Massachusetts  

SciTech Connect

To better understand the environmental factors controlling PAH fate in coastal sediments and to obtain more realistic estimates of biodegradation rates and removal of polycyclic aromatic hydrocarbons (PAHs) from coastal systems, the authors examined the effect of sediment organic matter concentration and previous contaminant loadings on bioavailability, biotransformation, and biodegradation of two model PAHs: phenanthrene (PHN) and benzanthracene (BA) in benthic microcosms. These processes were assessed in the presence and absence of two representative infaunal organisms, the deposit feeding polychaete Scolecolepides viridis and the suspension feeding bivalve Mya arenaria. Organic carbon content of the sediment does not appear to be the primary controlling factor for PAH accumulation or metabolism by macrofauna or metabolism and degradation by microbes. Susceptibility of an individual PAH to prokaryotic degradation differs from its susceptibility to metabolism by eukaryotes. S. viridis, accumulated more PHN and Ba than M.arenaria. In addition, worms rapidly metabolized PAH, with polar metabolites accounting for more than 50% of the total body burdens of PAH measured. Most, and in some cases almost all, material removed from the sediment reservoir had been transformed into polar metabolites or completely mineralized to CO{sub 2}. Efforts should be made to include metabolism in fate and transport models of PAH in nearshore benthic environments.

McElroy, A.E. [State Univ. of New York, Stony Brook, NY (United States); MacGillivray, A.R. [Weston Inc., Lionville, PA (United States); Shiaris, M.P. [Univ. of Massachusetts, Boston, MA (United States); Sisson, J.D. [Woods Hole Oceanographic Institution, MA (United States)

1994-12-31

303

Biological and abiotic losses of polynuclear aromatic hydrocarbons (PAHs) from soils freshly amended with sewage sludge  

SciTech Connect

Sewage sludge containing typical indigenous concentrations of polynuclear aromatic hydrocarbons (PAHs) was applied to several different soils in glass microcosms. Biologically active and sterilized soils were monitored for PAH content over a period of approximately 205 d. Agricultural soils with and without previous exposure to sewage sludge were tested, together with a forest soil and a soil from a major roadside. Loss of PAHs from a soil spike with a PAH standard solution was also investigated. Results indicate the PAH compounds with less than four benzene rings are susceptible to abiotic loss processes. However, losses by these mechanisms were insignificant for compounds with four or more benzene rings. Half-lives for the sludge-applied PAHs were derived and indicated a strong dependence of persistence on chemical structure. Half-lives for phenanthrene and benzo[ghi]perylene were between 83 and 193 d and 282 and 535 d, respectively. Mean half-lives correlate directly with log K[sub ow] and inversely with log water solubility. Behavior of PAHs was different in each soil, probably due to different soil characteristics and history of PAH exposure. The soil spiked with PAHs provided the lowest half-life values for most PAH compounds, suggesting a higher susceptibility of spiked PAHs to both abiotic and biological degradation.

Wild, S.R.; Jones, K.C. (Lancaster Univ. (United Kingdom))

1993-01-01

304

Aromatic hydrocarbons associated with brines from geopressured wells  

SciTech Connect

The measurement of basic physical chemical properties of the brine components produced in the US DOE geopressured wells it necessary to provide the fundamental data necessary for an understanding of the mechanisms by which constituents of petroleum migrate and are partitioned into different phases in various geologic strata. The cryocondensate materials, which we sample, are present in the geopressured brines of all the wells observed to date. These materials are a complex mixture of aromatic compounds ranging in complexity from benzene to alkyl substituted anthracenes. This progress report includes articles published in the open literature from the data and findings of this project. Topics include the solubility and thermodynamic distribution coefficients. To accomplish these measurements of solubility and distribution coefficients, new techniques and new equipment were developed and were also published as journal articles.

Keeley, D.F.; Meriwether, J.R.

1989-01-01

305

Characterization of subsurface polycyclic aromatic hydrocarbons at the Deepwater Horizon site  

NASA Astrophysics Data System (ADS)

Here, we report the initial observations of distributions of polycyclic aromatic hydrocarbons (PAH) in subsurface waters near the Deepwater Horizon oil well site (also referred to as the Macondo, Mississippi Canyon Block 252 or MC252 well). Profiles of in situ fluorescence and beam attenuation conducted during 9-16 May 2010 were characterized by distinct peaks at depths greater than 1000 m, with highest intensities close to the wellhead and decreasing intensities with increasing distance from the wellhead. Gas chromatography/mass spectrometry (GC/MS) analyses of water samples coinciding with the deep fluorescence and beam attenuation anomalies confirmed the presence of polycyclic aromatic hydrocarbons (PAH) at concentrations reaching 189 ?g L-1 (ppb). Subsurface exposure to PAH at levels considered to be toxic to marine organisms would have occurred in discrete depth layers between 1000 and 1400 m in the region southwest of the wellhead site and extending at least as far as 13 km.

Diercks, Arne-R.; Highsmith, Raymond C.; Asper, Vernon L.; Joung, DongJoo; Zhou, Zhengzhen; Guo, Laodong; Shiller, Alan M.; Joye, Samantha B.; Teske, Andreas P.; Guinasso, Norman; Wade, Terry L.; Lohrenz, Steven E.

2010-10-01

306

Remote detection of polynuclear aromatic hydrocarbons using laser-induced fluorescence. Interim report January 82-August 84  

SciTech Connect

This publication discusses the feasibility of remotely detecting gas-phase polynuclear aromatic hydrocarbons (PAHs) that might be produced during the combustion of propellant, explosive, and pyrotechnic (PEP) materials. Laboratory scale and remote laser-induced fluorescence measurements are presented.

Loda, R.T.

1985-01-01

307

BROMO- AND BROMOCHLORO-POLYNUCLEAR AROMATIC HYDROCARBONS, DIOXINS AND DIBENZOFURANS IN MUNICIPAL INCINERATOR FLY ASH (JOURNAL VERSION)  

EPA Science Inventory

A fly ash sample found to contain polychlorinated dioxins and dibenzofurans was analyzed for brominated analytes. Bromochloro-polynuclear aromatic hydrocarbons, dioxins and dibenzofurans, as well as bromo PAH were found in ppt to ppb concentrations. Analytical results were confir...

308

THE APPLICATION OF COMPUTATIONAL MOLECULAR METHODS TO UNDERSTAND THE HEALTH EFFECTS OF ENVIRONMENTAL CHEMICALS-POLYCYCLIC AROMATIC HYDROCARBONS  

EPA Science Inventory

In evaluating the risk posed by chemicals introduced into the environment, information about their molecular mechanism of action provides a basis for extrapolating from the laboratory to the environment. Polycyclic aromatic hydrocarbons (PAH) are a large class of...

309

Gas Chromatography/Matrix Isolation-Infrared Spectrometry for the Identification of Polycyclic Aromatic Hydrocarbons in Urban Air Particulate Matter.  

National Technical Information Service (NTIS)

The capabilities of gas chromatography/matrix isolation-infrared (GC/MI-IR) spectrometry for detecting and identifying polycyclic aromatic hydrocarbons (PAHs) in urban air particulate matter are demonstrated. The ability of GC/MI-IR to discriminate betwee...

J. W. Childers, N. K. Wilson, R. K. Barbour

1989-01-01

310

FORMATION OF POLYCYCLIC AROMATIC HYDROCARBONS AND THEIR GROWTH TO SOOT -A REVIEW OF CHEMICAL REACTION PATHWAYS. (R824970)  

EPA Science Inventory

The generation by combustion processes of airborne species of current health concern such as polycyclic aromatic hydrocarbons (PAH) and soot particles necessitates a detailed understanding of chemical reaction pathways responsible for their formation. The present review discus...

311

AVAILABILITY OF PCBS (POLYCHLORINATED BIPHENYLS) AND PAHS (POLYCYCLIC AROMATIC HYDROCARBONS) TO 'MYTILUJ EDULIS' FROM ARTIFICIALLY RESUSPENDED SEDIMENTS  

EPA Science Inventory

Estuarine sediment containing high levels of polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) was resuspended into a flowing seawater system. Analysis of the dissolved and particulate phases in the exposure tank indicated a release of some low molecula...

312

TRENDS OF POLYCYCLIC AROMATIC HYDROCARBON LEVELS AND MUTAGENICITY IN SANTIAGO'S INHALABLE AIRBORNE PARTICLES IN THE PERIOD 1992-1996.  

EPA Science Inventory

Abstract Trends of polycyclic aromatic hydrocarbons (PAHs) for 1992-1996 (cold season) and their mutagenic activity were investigated in organic extracts from the Santiago. Chile. inhalable particles (PM10). The highest PAH concentrations were observed in 1992 and decline...

313

CROSS-INDUCTION OF PYRENE AND PHENANTHRENE IN MYCOBACTERIUM SP. ISOLATED FROM POLYCYCLIC AROMATIC HYDROCARBON CONTAMINATED RIVER SEDIMENTS  

EPA Science Inventory

A polycyclic aromatic hydrocarbon (PAH)-degrading culture enriched from contaminated river sediments and a Mycobacterium sp. isolated from the enrichment were tested to investigate the possible synergistic and antagonistic interactions affecting the degradation of pyrene in the p...

314

Effectiveness of in site biodegradation for the remediation of polycyclic aromatic hydrocarbons at a contaminated oil refinery, Port Arthur, Texas  

E-print Network

The effectiveness of bioremediation for the removal of polycyclic aromatic hydrocarbons (PAHs) from sediments contaminated with highly weathered petroleum was evaluated at a contaminated oil refinery. The sediments were chronically contaminated...

Moffit, Alfred Edward

2012-06-07

315

PHOTOACTIVATED POLYCYCLIC AROMATIC HYDROCARBON TOXICITY IN MEDAKA (ORYZIAS LATIPES) EMBRYOS: RELEVANCE TO ENVIRONMENTAL RISK IN CONTAMINATED SITES  

EPA Science Inventory

The hazard for photoactivated toxicity of polycyclic aromatic hydrocarbons (PAHs) has been clearly demonstrated; however, to our knowledge, the risk in contaminated systems has not been characterized. To address this question, a median lethal dose (LD50) for fluoranthene photoa...

316

PILOT-SCALE SUBCRITICAL WATER REMEDIATION OF POLYCYCLIC AROMATIC HYDROCARBON- AND PESTICIDE-CONTAMINATED SOIL. (R825394)  

EPA Science Inventory

Subcritical water (hot water under enough pressure to maintain the liquid state) was used to remove polycyclic aromatic hydrocarbons (PAHs) and pesticides from highly contaminated soils. Laboratory-scale (8 g of soil) experiments were used to determine conditions f...

317

IMPORTANCE OF MATERNAL TRANSFER OF THE PHOTOREACTIVE POLYCYCLIC AROMATIC HYDROCARBON FLUORANTHENE FROM BENTHIC ADULT BIVALVES TO THEIR PELAGIC LARVAE  

EPA Science Inventory

Laboratory experiments were conducted to determine if maternal transfer of polycyclic aromatic hydrocarbons (PAHs) from benthic adult bivalves could result in phototoxicity to their pelagic larvae when exposed to ultraviolet light (UV). In these experiments, adult bivalves were e...

318

Long-Range Atmospheric Transport of Polycyclic Aromatic Hydrocarbons: A Global 3-D Model Analysis Including Evaluation of Arctic Sources  

E-print Network

We use the global 3-D chemical transport model GEOS-Chem to simulate long-range atmospheric transport of polycyclic aromatic hydrocarbons (PAHs). To evaluate the model’s ability to simulate PAHs with different volatilities, ...

Friedman, Carey

319

Polycyclic aromatic hydrocarbon distributions in Mississippi Fan sediments  

E-print Network

-diode array spectrophotometry (HPLC- DAS) was shown to be incapable of determining quantitative PAH distributions in this chemically complex system under several experimental conditions. TABLE OF CONTENTS Page ABSTRACT, TABLE OF CONTENTS LIST OF TABLES... EXPERIMENTAL PROCEDURE. 17 Sampling procedures Sample preparation, Sample analysis HPLC analysis 17 17 19 29 RESULTS 31 Lower fan site (Site 615) Middle fan site (Site 621). Fan margin (Site 616) Intraslope basins (Sites 618 and 619) General...

Sandberg, William Allan

2012-06-07

320

Solid Phase Extraction for Determination of Polycyclic Aromatic Hydrocarbons from Atmospheric Wet and Dry Deposition Samples  

Microsoft Academic Search

Solid phase extraction with C-18 sorbent tubes was employed for extraction and preconcentration of trace level (ng\\/l) of polycyclic aromatic hydrocarbons (PAHs) from water samples obtained by collecting wet and dry atmospheric deposition. Recoveries of spiked PAHs from 0.2 to 10.0 l water samples ranged from 60% to 90%. Five deuterated PAHs (naphthalene- d 8 , acenaphthene- d 10 ,

Pakorn Varanusupakul; Eugene F. Barry; George F. Fisher; Dan S. Golomb

2002-01-01

321

Laboratory studies of the remediation of polycyclic aromatic hydrocarbon contaminated soil by in-vessel composting  

Microsoft Academic Search

The biodegradation of 16 polycyclic aromatic hydrocarbons (PAHs), listed as priority pollutants by the USEPA, present in a coal-tar-contaminated soil from a former manufactured gas plant site was investigated using laboratory-scale in-vessel composting reactors to determine the suitability of this approach as a bioremediation technology. Preliminary investigations were conducted over 16 weeks to determine the optimum soil composting temperature (38,

Blanca Antizar-Ladislao; Joseph Lopez-Real; Angus J. Beck

2005-01-01

322

Polycyclic aromatic hydrocarbons (PAHs) in bio-crudes from induction-heating pyrolysis of biomass wastes  

Microsoft Academic Search

The aim of this work was to prepare the bio-crudes from agricultural wastes (i.e., rice straw, rice husk, sugarcane bagasse and coconut shell) by using induction-heating pyrolysis at specified conditions. The quantitative analysis of 21 priority pollutant polycyclic aromatic hydrocarbons (PAHs) in bio-crudes examined using gas chromatography\\/mass spectrometry (GC\\/MS) revealed that the PAHs in bio-crudes were primarily dominant in the

Wen-Tien Tsai; Hsiao-Hsuan Mi; Yuan-Ming Chang; Shyh-Yu Yang; Jeng-Hung Chang

2007-01-01

323

City centre concentrations of polycyclic aromatic hydrocarbons using supercritical fluid extraction  

Microsoft Academic Search

A method has been developed to allow routine quantitative analysis of polycyclic aromatic hydrocarbons (PAH) in urban dust particulates with a 12 h sampling time. Supercritical CO2 with polar modifier was used for extraction from sampling media and subsequent sample clean-up and analysis was performed using on-line HPLC-GC. Recoveries of PAH from a NIST certified urban dust sample SRM1649 were

Alastair C. Lewis; Dorota Kupiszewska; Keith D. Bartle; Michael J. Pilling

1995-01-01

324

Trimethylphenylammonium-Smectite as an Effective Adsorbent of Water Soluble Aromatic Hydrocarbons  

Microsoft Academic Search

Homoionic trimethylphenylammonium (TMPA)- and tetramethylammonium (TMA)-clays were prepared by Ion-exchange reactions using two smectite clays that differed in their cation exchange capacities and surface charge densities. These clays are referred to as a low-charge (SAC) and high-charge (SWa)-smectite. The organo-clays were evaluated as adsorbents of water soluble aromatic hydrocarbons including benzene, toluene, ethylbenzene, p-xylene, butylbenzene, and naphthalene. All of the

William F. Jaynes; Stephen A. Boyd

1990-01-01

325

Polycyclic Aromatic Hydrocarbons (PAHs) in Sediments of the White Sea, Russia  

Microsoft Academic Search

The extent of environmental contamination and sources of polycyclic aromatic hydrocarbon (PAH) compounds to sediments of the White Sea are evaluated and compared with previously published results for adjacent Arctic Sea areas. Concentrations of two- to six-ring PAHs of molecular mass 128–278 including perylene and sediment characteristics are considered in this investigation. Mean ?PAH concentration was 61±34 ng\\/g dw (n=11)

Vladimir M Savinov; Tatiana N Savinova; JoLynn Carroll; Gennady G Matishov; Salve Dahle; Kristoffer Næs

2000-01-01

326

Determination of polycyclic aromatic hydrocarbons in smoked meat products and smoke flavouring food additives  

Microsoft Academic Search

Formation, factors affecting concentrations, legal limits and occurrence of polycyclic aromatic hydrocarbons in smoked meat products and smoke flavour additives are briefly reviewed. The most used techniques such as thin-layer chromatography (TLC), gas chromatography (GC) and high-performance liquid chromatography (HPLC) are evaluated. Also, sample preparation, pre-separation procedures, separation and detection systems being used for determination are discussed with emphasis to

Peter Šimko

2002-01-01

327

Measurement of polycyclic aromatic hydrocarbons associated with size-segregated atmospheric aerosols in Massachusetts  

Microsoft Academic Search

Size-segregated atmospheric aerosols were collected from urban and rural locations in Massachusetts using a micro-orifice impactor. The samples were analyzed for polycyclic aromatic hydrocarbons (PAH) with molecular weight between 178 and 302, using gas chromatography\\/mass spectrometry. Fifteen PAH were quantified in the urban samples and nine in the rural samples. The quantification results are in good agreement with available ambient

Jonathan O. Allen; Nameeta M. Dookeran; Kenneth A. Smith; Adel F. Sarofim; Koli Taghizadeh; Arthur L. Lafleur

1996-01-01

328

Preparing an active cerium oxide catalyst for the catalytic incineration of aromatic hydrocarbons  

Microsoft Academic Search

We tested the efficacy of seven metal oxide catalysts in the catalytic incineration of aromatic hydrocarbons and found CeO2 to be the most active of the seven. With the use of CeO2, complete oxidation of toluene was achieved at 240°C. There was a similar outcome in the incineration of p-xylene, whereas benzene was more refractory. In preparation of the CeO2

Ching-Huei Wang; Shiow-Shyung Lin

2004-01-01

329

Complete Genome Sequence of the Polycyclic Aromatic Hydrocarbon-Degrading Bacterium Alteromonas sp. Strain SN2?  

PubMed Central

Alteromonas sp. strain SN2, able to metabolize polycyclic aromatic hydrocarbons, was isolated from a crude oil-contaminated sea-tidal flat. Here we report the complete 4.97-Mb genome sequence and annotation of strain SN2. These will advance the understanding of strain SN2's adaptation to the sea-tidal flat ecosystem and its pollutant metabolic versatility. PMID:21705606

Jin, Hyun Mi; Jeong, Haeyoung; Moon, Eun-Joung; Math, Renukaradhya K.; Lee, Kangseok; Kim, Hae-Jin; Jeon, Che Ok; Oh, Tae Kwang; Kim, Jihyun F.

2011-01-01

330

Optimization by factorial design of focused microwave assisted extraction of polycyclic aromatic hydrocarbons from marine sediment  

Microsoft Academic Search

The Focused Microwave (FMW) assisted extraction for organic contaminant analysis, such as polycyclic aromatic hydrocarbons\\u000a (PAHs), in environmental matrices, was studied and optimized using a factorial design. The effects and interactions of five\\u000a parameters on the extraction recovery were investigated in a few experiments with a good accuracy: irradiation power and time,\\u000a volume and nature of solvent, and percentage of

M. Letellier; H. Budzinski; L. Charrier; S. Capes; A. M. Dorthe

1999-01-01

331

Toxicity of polycyclic aromatic hydrocarbons. (Latest citations from Pollution abstracts). Published Search  

SciTech Connect

The bibliography contains citations concerning the toxicity and biochemical effects of aromatic polycyclic hydrocarbons. Topics include effects on metabolism and liver activity, cellular responses, binding characteristics, and the occurrence and path of the compounds in food chains. Bioaccumulation studies in specific areas, and isolation and detection techniques are also considered. (Contains a minimum of 242 citations and includes a subject term index and title list.)

Not Available

1994-06-01

332

Occurrence and distribution of polycyclic aromatic hydrocarbons in the Egyptian aquatic environment  

Microsoft Academic Search

Persistent organic pollutants (POPs) such as polycyclic aromatic hydrocarbons (PAHs) are of great concern due to their persistence, bioaccumulation and toxic effects. In this study, water samples were collected during 2007–2008 from two catchment areas that represent two different models of the aquatic environment in Egypt (Rosetta branch as fresh water and El-Moheet drain as untreated\\/treated waste water). The distribution

Hossam S. Jahin; Barsoum N. Barsoum; Tarik A. Tawfic; John V. Headley

2009-01-01

333

Occurrence and distribution of polycyclic aromatic hydrocarbons in reclaimed water and surface water of Tianjin, China  

Microsoft Academic Search

Persistent organic pollutants (POPs) such as polycyclic aromatic hydrocarbons (PAHs) are of great concern due to their persistence, bioaccumulation and toxic effects. In this work, 16 PAHs included in the US Environmental Protection Agency's (EPA) priority pollutant list were analyzed using solid-phase extraction–gas chromatography–mass spectrometry (SPE–GC–MS) with a selected ion monitoring (SIM) mode. Reclaimed water and surface water sampling was

Zhonghong Cao; Yuqiu Wang; Yongmin Ma; Ze Xu; Guoliang Shi; Yuanyi Zhuang; Tan Zhu

2005-01-01

334

Amino-acids, Aliphatic and Aromatic Hydrocarbons in the Murchison Meteorite  

Microsoft Academic Search

Two recently fallen carbonaceous chondrites have provided organic analytical results significantly different from those obtained with other carbonaceous chondrites1-3. The Allende meteorite, a type III carbonaceous chondrite which contains 0.27% carbon and 0.007% nitrogen4, was shown to have only traces of extractable organic compounds5. Small amounts of aliphatic and aromatic hydrocarbons were released by heating while no significant amounts of

J. Oró; J. Gibert; H. Lichtenstein; S. Wikstrom; D. A. Flory

1971-01-01

335

The Distribution of Polycyclic Aromatic Hydrocarbons in the Wetland Soil Irrigated by Pulp Waste Water  

Microsoft Academic Search

The distribution characteristics of eleven polycyclic aromatic hydrocarbons (PAHs) in the pulp waste water and in seashore wetland soil irrigated by the waste water were detected by GC-ECD. The result shows that the concentrations of PAHs in the gray water, bleached water, black liquid and integrated waste water ranged from 12.826 to 16.83 mu g-1. The total amount of PAHs

Cheng Ding; Wang Shihe; Yang Chunsheng

2006-01-01

336

Aromatic Hydrocarbons in Biota from the Detroit River and Western Lake Erie  

Microsoft Academic Search

Polynuclear aromatic hydrocarbons (PAHs) and PCBs in zebra mussels were elevated to concentrations greater than 5,000 ng\\/g lipid and 15,000 ng\\/g lipid, respectively, at the Ambassador Bridge in the Detroit River and concentrations gradually declined at downstream locations, which included three stations in the western basin of Lake Erie (Middle Sister Island, East Sister Island, Pelee Island). PCB concentrations in

Chris D. Metcalfel; Tracy L. Metcalfe; Geoffrey Riddle; G. Douglas Haffner

1997-01-01

337

A Study for the Proper Application of Urinary Naphthols, New Biomarkers for Airborne Polycyclic Aromatic Hydrocarbons  

Microsoft Academic Search

.   Urinary naphthols, 1- and 2-naphthol, recently have been suggested as route-specific biomarkers for exposure to airborne\\u000a polycyclic aromatic hydrocarbons. For the proper application of urinary naphthols as biomarkers, we studied effects of lifestyle\\u000a on urinary naphthols levels in 119 Japanese male workers. After improving the detection limit of urinary naphthols up to 0.27\\u000a ?g\\/L by high-resolution capillary gas chromatography\\/mass

M. Yang; M. Koga; T. Katoh; T. Kawamoto

1999-01-01

338

Chlorinated Polycyclic Aromatic Hydrocarbons in Sediments from Industrial Areas in Japan and the United States  

Microsoft Academic Search

Chlorinated polycyclic aromatic hydrocarbons (ClPAHs) are widespread environmental pollutants in the urban environment. Nevertheless,\\u000a there is little information available regarding the occurrence and profiles of ClPAHs in environmental matrices. In this study,\\u000a residual concentrations and profiles of 20 individual ClPAHs and 16 US EPA-priority PAHs were determined using high- resolution\\u000a gas chromatography–high-resolution mass spectrometry in sediments from water bodies near

Yuichi Horii; Takeshi Ohura; Nobuyoshi Yamashita; Kurunthachalam Kannan

2009-01-01

339

Toxicity of aromatic polycyclic hydrocarbons. (Latest citations from the Life Sciences Collection database). Published Search  

SciTech Connect

The bibliography contains citations concerning the toxicity and biochemical effects of aromatic polycyclic hydrocarbons. Topics include effects on metabolism and liver activity, cellular responses, binding characteristics, and the occurrence and path of the compounds in food chains. Bioaccumulation studies in specific areas, and isolation and detection techniques are also considered. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

NONE

1997-04-01

340

Rinodina sophodes (Ach.) Massal.: a bioaccumulator of polycyclic aromatic hydrocarbons (PAHs) in Kanpur City, India  

Microsoft Academic Search

The aim of this study is to determine the possibility of using Rinodina sophodes (Ach.) Massal., a crustose lichen as polycyclic aromatic hydrocarbons (PAHs) bioaccumulator for evaluation of atmospheric\\u000a pollution in tropical areas of India, where few species of lichens are able to grow. PAHs were identified, quantified and\\u000a compared to evaluate the potential utility of R. sophodes. The limit

Satya; Dalip K. Upreti; D. K. Patel

341

Screening filamentous fungi isolated from estuarine sediments for the ability to oxidize polycyclic aromatic hydrocarbons  

Microsoft Academic Search

Nineteen filamentous fungi, isolated from estuarine sediments in Brazil, were screened for degradation of polycyclic aromatic hydrocarbons (PAH). The fungal isolates were incubated with pyrene. The cultures were extracted and metabolites in the extracts were detected by high performance liquid chromatography (HPLC) and u.v. spectral analyses. Six fungi were selected for further studies using [4,5,9,10-14C]pyrene. Cyclothyrium sp., Penicillium simplicissimum, Psilocybe

Manuela da Silva; Carl E. Cerniglia; Jairaj V. Pothuluri; Vanderlei P. Canhos; Elisa Esposito

2003-01-01

342

Air Pollution from a Large Steel Factory: Polycyclic Aromatic Hydrocarbon Emissions from Coke-Oven Batteries  

Microsoft Academic Search

A systematic investigation of solid and gaseous atmospheric emissions from some coke-oven batteries of one of Europe’s largest integrated steel factory (Taranto, Italy) has been carried out. In air monitoring samples, polycyclic aromatic hydrocarbons (PAHs) were consistently detected at concentrations largely exceeding threshold limit values. By means of PAHs speciation profile and benzo (a)pyrene (BaP) equivalent dispersion modeling from diffuse

Lorenzo Liberti; Michele Notarnicola; Roberto Primerano; Paolo Zannetti

2006-01-01

343

Polycyclic aromatic hydrocarbons in sediments and associated benthos in Lake Erie  

SciTech Connect

Polycyclic aromatic hydrocarbons (PAH) were analyzed in surficial sediments and benthic organisms in southwestern Lake Erie near a large coal fired power plant. Sediment concentrations (530-770 ppb PAH) were relatively homogenous throughout most of the 150 km/sup 2/ area, although river and nearshore concentrations reached nearly 4 ppm. Oligochaete worms and chironomid midges were near equilibrium with local sediments except for enhanced concentrations in nearshore midges.

Eadie, B.J.; Faust, W.; Gardner, W.S.; Nalepa, T.

1982-01-01

344

QSAR Estimates of Excited States and Photoinduced Acute Toxicity of Polycyclic Aromatic Hydrocarbons  

Microsoft Academic Search

Direct calculation of the energy of excited states for polycyclic aromatic hydrocarbons using semi-empirical methods on a supercomputer were inadequate in explaning spectrosopic data or measured phototoxicity. The energy difference between frontier orbitals HOMO-LUMO gap of “average” excited state structures of the PAHs correlated with the measured excited state energies and their observed photoinduced toxicity. The multi-linear relationship between phototoxicity

O. G. Mekenyan; G. T. Ankley; G. D. Veith; D. J. Call

1994-01-01

345

Molecular models of benzene and selected polycyclic aromatic hydrocarbons in the aqueous and adsorbed states  

Microsoft Academic Search

Energy gaps between the highest-occupied molecular orbital and lowest-unoccupied molecular orbital (ÎE{sub HOMO-LUMO}) for a suite of common polycyclic aromatic hydrocarbons (PAHs) in the gas-phase were calculated with three different molecular modeling methods: semiempirical, ab initio Hartree-Fock, and density functional calculations. Results indicate that semiempirical, Hartree-Fock, and density functional calculations may provide useful relative HOMO-LUMO gap information, but these methods

J. D. Kubicki; G. A. Blake; S. E. Apitz

1999-01-01

346

Isomer discrimination of polycyclic aromatic hydrocarbons in the Murchison meteorite by resonant ionization  

Microsoft Academic Search

We have used two-color resonant two-photon ionization (2C-R2PI) mass spectrometry to discriminate between isomers of polycyclic aromatic hydrocarbons in the Murchison meteorite. We measured the 2C-R2PI spectra of chrysene and triphenylene seeded in a supersonic jet by laser desorption. Since each isomer differs in its R2PI spectrum, we can distinguish between isomers using wavelength dependent ionization and mass spectrometry. We

Michael P. Callahan; Ali Abo-Riziq; Bridgit Crews; Louis Grace; Mattanjah S. de Vries

2008-01-01

347

Polycyclic aromatic hydrocarbons, particulates, and defense mechanisms (VKC-BAB-145). Final report  

Microsoft Academic Search

The interaction of polycyclic aromatic hydrocarbons, represented by benzo(a)pyrene (BaP), and particulates in carcinogenesis was investigated. The systemic administration of BaP has been shown to significantly depress the whole animal interferon response to viral stimulation, suggesting this may be an early expression of immunotoxicity. BaP requires bioactivation to inhibit interferon induction. The research activities and significant findings and accomplishments germane

Hahon

1988-01-01

348

Occupational exposure to polycyclic aromatic hydrocarbons and lung cancer risk: a multicenter study in Europe  

Microsoft Academic Search

BackgroundLung cancer incidence in Central and Eastern Europe (CEE) is among the highest in the world, and the role of occupational exposures has not been adequately studied in these countries.ObjectivesTo investigate the contribution of occupational exposure to polycyclic aromatic hydrocarbons (PAH) to lung cancer in CEE.MethodsA case–control study was conducted in the Czech Republic, Hungary, Poland, Romania, Russia and Slovakia,

Ann C Olsson; Joelle Fevotte; Tony Fletcher; Adrian Cassidy; Andrea t Mannetje; David Zaridze; Neonila Szeszenia-Dabrowska; Peter Rudnai; Jolanta Lissowska; Eleonora Fabianova; Dana Mates; Vladimir Bencko; Lenka Foretova; Vladimir Janout; Paul Brennan; Paolo Boffetta

2009-01-01

349

Autecological properties of soil sphingomonads involved in the degradation of polycyclic aromatic hydrocarbons  

Microsoft Academic Search

Autecological properties that are thought to be important for polycyclic aromatic hydrocarbon (PAH)-degradation by bacteria in contaminated soils include the ability to utilize a broad range of carbon sources, efficient biofilm formation, cell-surface hydrophobicity, surfactant production, motility, and chemotaxis. Sphingomonas species are common PAH-degraders, and a selection of PAH-degrading sphingomonad strains isolated from contaminated soils was therefore characterized in terms

Michael Cunliffe; Michael A. Kertesz

2006-01-01

350

Polycyclic aromatic hydrocarbon (PAH) emissions from a coal-fired pilot FBC system  

Microsoft Academic Search

Due to the extensive amount of data suggesting the hazards of these compounds, 16 polycyclic aromatic hydrocarbons (PAHs) are on the Environmental Protection Agency (EPA) Priority Pollutant List. Emissions of these PAHs in the flue gas from the combustion of four coals were measured during four 1000h combustion runs using the 0.1MW heat-input (MWth) bench-scale fluidized bed combustor (FBC). An

Kunlei Liu; Wenjun Han; Wei-Ping Pan; John T. Riley

2001-01-01

351

Isolation and Characterization of Polycyclic Aromatic Hydrocarbon–Degrading Mycobacterium Isolates from Soil  

Microsoft Academic Search

Bioremediation of soils contaminated with wood preservatives containing polycyclic aromatic hydrocarbons (PAHs) is desired because of their toxic, mutagenic, and carcinogenic properties. Creosote wood preservative–contaminated soils at the Champion International Superfund Site in Libby, Montana currently undergo bioremediation in a prepared-bed land treatment unit (LTU) process. Microbes isolated from these LTU soils rapidly mineralized the 14C-labeled PAH pyrene in the

C. D. Miller; K. Hall; Y. N. Liang; K. Nieman; D. Sorensen; B. Issa; A. J. Anderson; R. C. Sims

2004-01-01

352

Polycyclic aromatic hydrocarbon biodegradation and extracellular enzyme secretion in agitated and stationary cultures of Phanerochaete chrysosporium  

Microsoft Academic Search

The extracellular enzyme secretion and biodegradation of polycyclic aromatic hydrocarbons (PAHs) were studied in agitated and shallow stationary liquid cultures of Phanerochaete chrysosporium. Veratryl alcohol and Tween80 were added to cultures as lignin peroxidase (LiP) and manganese peroxidase (MnP) inducer, respectively. Shallow stationary cultures were suitable for the production of enzyme, whereas agitated cultures enhanced overall biodegradation by facilitating interphase

Juan DING; Jun CONG; Juan ZHOU; Shixiang GAO

2008-01-01

353

Isolation of adherent polycyclic aromatic hydrocarbon (PAH)-degrading bacteria using PAH-sorbing carriers  

Microsoft Academic Search

Two different procedures were compared to isolate polycyclic aromatic hydrocarbon (PAH)-utilizing bacteria from PAH-contaminated soil and sludge samples, i.e., (i) shaken enrichment cultures in liquid mineral medium in which PAHs were supplied as crystals and (ii) a new method in which PAH degraders were enriched on and recovered from hydrophobic membranes containing sorbed PAHs. Both techniques were successful, but selected

LEEN BASTIAENS; DIRK SPRINGAEL; PIERRE WATTIAU; HAUKE HARMS; RUPERT DEWACHTER; HUBERT VERACHTERT; LUDO DIELS

2000-01-01

354

Chemotaxis in polycyclic aromatic hydrocarbon-degrading bacteria isolated from coaltar and oil-polluted rhizospheres  

Microsoft Academic Search

The limited mass transfer in polycyclic aromatic hydrocarbon (PAH)-contaminated soils during bioremediation treatments often impedes the achievement of regulatory decontamination end-points. Little is known about bioavailability of these hydrophobic pollutants in phytoremediation systems. This work attempts to evaluate, for the first time, chemotaxis as a bioavailability-promoting trait in PAH-degrading bacteria from the rhizosphere. For this aim, 20 motile strains capable

J. J. Ortega-Calvo; A. I. Marchenko; A. V. Vorobyov; R. V. Borovick

2003-01-01

355

PHENOTYPIC RESPONSES OF THE SOIL BACTERIAL COMMUNITY TO POLYCYCLIC AROMATIC HYDROCARBON CONTAMINATION IN SOILS  

Microsoft Academic Search

Five soils with different levels of polycyclic aromatic hydrocarbon (PAH) and metallic contamination were sampled from a former coke facility site located in the north of France. Among PAH-degrading microbiota, naphthalene-degraders were ubiquitous, whereas bacteria-degrading PAHs of more than two rings were present in only the polluted soils, in the range of 1% to 10% of the total microbiota. Phenotypic

C. Lors; J. R. Mossmann; P. Barbé

2004-01-01

356

Evaluation of bacterial strategies to promote the bioavailability of polycyclic aromatic hydrocarbons  

Microsoft Academic Search

Polycyclic aromatic hydrocarbon (PAHs)-degrading bacteria may enhance the bioavailability of PAHs by excreting biosurfactants, by production of extracellular polymeric substances, or by forming biofilms. We tested these hypotheses in pure cultures of PAHs-degrading bacterial strains. Most of the strains did not substantially reduce the surface tension when grown on PAHs in liquid shaken cultures. Thus, pseudo-solubilization of PAHs in biosurfactant

A. R. Johnsen; U. Karlson

2004-01-01

357

Kinetics of Polycyclic Aromatic Hydrocarbon (PAH) Degradation in Long-term Polluted Soils during Bioremediation  

Microsoft Academic Search

Bioremediation experiments with ten different soil samples from former industrial sites which were long-term polluted with\\u000a polycyclic aromatic hydrocarbons (PAHs) were carried out using outdoor pot trials. The degradation of 15 PAHs according to\\u000a the US EPA was investigated for 168 weeks through repeated soil sampling and determination of the total PAH concentration.\\u000a On average, degradation was largest for acenaphthene

S. Thiele-Bruhn; G. W. Brümmer

2005-01-01

358

Occurrence and community composition of fast-growing Mycobacterium in soils contaminated with polycyclic aromatic hydrocarbons  

Microsoft Academic Search

Fast-growing mycobacteria are considered essential members of the polycyclic aromatic hydrocarbons (PAH) degrading bacterial community in PAH-contaminated soils. To study the natural role and diversity of the Mycobacterium community in contaminated soils, a culture-independent fingerprinting method based on PCR combined with denaturing gradient gel electrophoresis (DGGE) was developed. New PCR primers were selected which specifically targeted the 16S rRNA genes

Natalie M. Leys; Annemie Ryngaert; Leen Bastiaens; Pierre Wattiau; Eva M. Top; Willy Verstraete; Dirk Springael

2005-01-01

359

Analyses of polycyclic aromatic hydrocarbon-degrading bacteria isolated from contaminated soils  

Microsoft Academic Search

Polycyclic aromatic hydrocarbon (PAH)-degrading bacteria isolated from PAH-contaminated soils were analyzed genotypically and phenotypically for their capacity for metabolism of naphthalene and other PAH substrates. The methods used for the analyses were DNA hybridization using NAH7-derived gene probes, PAH spray plate assays, 14C-PAH mineralization assays, and dioxygenase activity assays. The results of the analyses showed a dominant number of PAH-degrading

Yeonghee Ahn; John Sanseverino; Gary S. Sayler

1999-01-01

360

Bioaugmentation and composting of oil-field drill-cuttings containing polycyclic aromatic hydrocarbons (PAHs)  

Microsoft Academic Search

The potentials of bioaugmentation and composting as bioremediation technologies for the removal of polycyclic aromatic hydrocarbons (PAHs) from oil-field drill-cuttings have been compared. From a mud-pit close to a just-completed crude-oil well in the Niger Delta region of Nigeria, 4000 g of drill cuttings was obtained and homogenized with 667 g of top-soil (to serve as microbes carrier) in three

Josiah M. Ayotamuno; Reuben N. Okparanma; Peremelade P. Arak

2009-01-01

361

Atmospheric deposition of polycyclic aromatic hydrocarbons (PAHs) in mosses ( Hypnum cupressiforme) in Hungary  

Microsoft Academic Search

The atmospheric deposition of polycyclic aromatic hydrocarbons (PAHs) was investigated in Hungary by analyzing a moss (Hypnum cupressiforme) species as a bioindicator. In the autumn of 1997, samples were collected at 29 sites distributed across Hungary. The concentrations of total PAH at these sites were in the range of 0.1567–10.45×104 ?g kg?1 with a mean value of 1.87×104 ?g kg?1.

E. Ötvös; I. O. Kozák; J. Fekete; V. K. Sharma; Z. Tuba

2004-01-01

362

Biodegradation of polycyclic aromatic hydrocarbons by Sphingomonas strains isolated from the terrestrial subsurface  

Microsoft Academic Search

  Several strains of Sphingomonas isolated from deep Atlantic coastal plain aquifers at the US Department of Energy Savannah River Site (SRS) near Aiken, SC\\u000a were shown to degrade a variety of aromatic hydrocarbons in a liquid culture medium. Sphingomonas aromaticivorans strain B0695 was the most versatile of the five strains examined. This strain was able to degrade acenaphthene, anthracene,\\u000a phenanthrene,

T Shi; Jim K. Fredrickson; David L. Balkwill

2001-01-01

363

Physiological and Genetic Comparison of Two Aromatic Hydrocarbon-degrading Sphingomonas Strains  

Microsoft Academic Search

Sphingomonas yanoikuyae strain B1 is able to degrade a wider range of aromatic hydrocarbons than S. paucimobilis strain TNE12 can degrade. Various culture techniques were used to corroborate that B1 used m-xylene, biphenyl, toluene, naphthalene, and phenanthrene as sole carbon and energy sources. In contrast, TNE12 could not\\u000a mineralize m-xylene, biphenyl, toluene, or naphthalene. However, fluoranthene served as carbon and

Kay L. Shuttleworth; Junghee Sung; Eungbin Kim; Carl E. Cerniglia

2000-01-01

364

Correlation between biomarkers of polycyclic aromatic hydrocarbon exposure and electrophilic tissue burden in a rat model  

Microsoft Academic Search

This study was aimed at investigating the correlation between biomarkers of exposure to polycyclic aromatic hydrocarbons and, more specifically, at examining the role of urinary 1-hydroxypyrene (1-OHP) as a reliable measure of internal dose linked to the electrophilic tissue burden (ETB), assessed as covalent binding of the ultimate carcinogen benzo( a)pyrene diolepoxide (BaPDE) with cellular proteins in target organs. The

Adela Tzekova; Ross Thuot; Claude Viau

2004-01-01

365

Draft Genome Sequence of Sphingobium sp. Strain C100, a Polycyclic Aromatic Hydrocarbon-Degrading Bacterium from the Deep-Sea Sediment of the Arctic Ocean  

PubMed Central

Sphingobium sp. strain C100 was isolated from a polycyclic aromatic hydrocarbon (PAH)-degrading consortium from the deep-sea sediment of the Arctic Ocean. It can degrade two- to four-ring PAHs at 25°C. Here we present the draft genome sequence of this strain, which is 4,776,810 bp with a G+C content of 63.9%. PMID:24482512

Dong, Chunming; Bai, Xiuhua; Lai, Qiliang; Xie, Yanrong; Chen, Xin

2014-01-01

366

Draft Genome Sequence of Sphingobium sp. Strain C100, a Polycyclic Aromatic Hydrocarbon-Degrading Bacterium from the Deep-Sea Sediment of the Arctic Ocean.  

PubMed

Sphingobium sp. strain C100 was isolated from a polycyclic aromatic hydrocarbon (PAH)-degrading consortium from the deep-sea sediment of the Arctic Ocean. It can degrade two- to four-ring PAHs at 25°C. Here we present the draft genome sequence of this strain, which is 4,776,810 bp with a G+C content of 63.9%. PMID:24482512

Dong, Chunming; Bai, Xiuhua; Lai, Qiliang; Xie, Yanrong; Chen, Xin; Shao, Zongze

2014-01-01

367

Derivation of a chronic reference dose and reference concentration for trimethylbenzenes and C9 aromatic hydrocarbon solvents  

Microsoft Academic Search

Trimethylbenzenes (TMBs) and C9 aromatic hydrocarbon solvents are structurally similar and have similar toxicity. Based on a review of the entire TMB and C9 aromatic hydrocarbon solvents toxicology database, oral and inhalation studies were identified to serve as the basis for a Reference dose (RfD) and Reference concentrations (RfC). The RfD and RfC were derived using standard USEPA methods and

Michael J. Firth

2008-01-01

368

Deuterium Enrichment of Polycyclic Aromatic Hydrocarbons by Photochemically Induced Exchange with Deuterium-rich Cosmic Ices  

NASA Astrophysics Data System (ADS)

The polycyclic aromatic hydrocarbon (PAH) coronene (C24H12) frozen in D2O ice in a ratio of less than 1 part in 500 rapidly exchanges its hydrogen atoms with the deuterium in the ice at interstellar temperatures and pressures when exposed to ultraviolet radiation. Exchange occurs via three different chemical processes: D atom addition, D atom exchange at oxidized edge sites, and D atom exchange at aromatic edge sites. Observed exchange rates for coronene (C24H12)-D2O and d12-coronene (C24D12)-H2O isotopic substitution experiments show that PAHs in interstellar ices could easily attain the D/H levels observed in meteorites. These results may have important consequences for the abundance of deuterium observed in aromatic materials in the interstellar medium and in meteorites. These exchange mechanisms produce deuteration in characteristic molecular locations on the PAHs that may distinguish them from previously postulated processes for D enrichment of PAHs.

Sandford, Scott A.; Bernstein, Max P.; Allamandola, Louis J.; Gillette, J. Seb; Zare, Richard N.

2000-08-01

369

Polyphenol oxidase activity in subcellular fractions of tall fescue contaminated by polycyclic aromatic hydrocarbons.  

PubMed

Understanding enzyme responses to contamination with persistent organic pollutants (POPs) is a key step in the elucidation of POP metabolic mechanisms in plants. However, there is little information available on enzyme activity in subcellular fractions of POP-contaminated plants. To our knowledge, this is the first study to investigate the activities of polyphenol oxidase (PPO) in cell fractions of plants under contamination stress from polycyclic aromatic hydrocarbons (PAHs) using a greenhouse batch technique. Three parameters, E(cell), E(cell-n), and P(cell), denoting the amount of PPO activity, cell fraction content-normalized PPO activity, and proportion of PPO activity in each cell fraction, respectively, were used in this study. Contamination with phenanthrene, as a representative PAH, at a relatively high level (>0.23 mg L?¹) in culture solution generally stimulated PPO activity in tall fescue (Festuca arundinacea Schreb.) roots and shoots and their cellular fractions. The amount and distribution proportion of PPO activity in each cell fraction of phenanthrene-contaminated roots and shoots were (in descending order): cell solution > > cell wall > cell organelles. Cell solution was the dominant storage domain of PPO activity and contributed 84.0 and 82.8% of PPO activity in roots and shoots, respectively. The cell wall had the highest density of PPO activity in roots and shoots, based on the highest cell fraction content normalized PPO activity in this cell fraction. Our results provide new information on enzyme responses in plant intracellular fractions to xenobiotic POPs and fundamental information on within-plant POP metabolic mechanisms. PMID:22565262

Ling, Wanting; Lu, Xiaodan; Gao, Yanzheng; Liu, Juan; Sun, Yandi

2012-01-01

370

Bioavailability and potential carcinogenicity of polycyclic aromatic hydrocarbons from wood combustion particulate matter in vitro.  

PubMed

Due to increasing energy demand and limited fossil fuels, renewable energy sources have gained in importance. Particulate matter (PM) in general, but also PM from the combustion of wood is known to exert adverse health effects in human. These are often related to specific toxic compounds adsorbed to the PM surface, such as polycyclic aromatic hydrocarbons (PAH), of which some are known human carcinogens. This study focused on the bioavailability of PAHs and on the tumor initiation potential of wood combustion PM, using the PAH CALUX® reporter gene assay and the BALB/c 3T3 cell transformation assay, respectively. For this, both cell assays were exposed to PM and their respective organic extracts from varying degrees of combustion. The PAH CALUX® experiments demonstrated a concentration-response relationship matching the PAHs detected in the samples. Contrary to expectations, PM samples from complete (CC) and incomplete combustion (IC) provided for a stronger and weaker response, respectively, suggesting that PAH were more readily bioavailable in PM from CC. These findings were corroborated via PAH spiking experiments indicating that IC PM contains organic components that strongly adsorb PAH thereby reducing their bioavailability. The results obtained with organic extracts in the cell transformation assay presented the highest potential for carcinogenicity in samples with high PAH contents, albeit PM from CC also demonstrated a carcinogenic potential. In conclusion, the in vitro assays employed emphasize that CC produces PM with low PAH content however with a general higher bioavailability and thus with a nearly similar carcinogenic potential than IC PM. PMID:23796820

Gauggel-Lewandowski, Susanne; Heussner, Alexandra H; Steinberg, Pablo; Pieterse, Bart; van der Burg, Bart; Dietrich, Daniel R

2013-11-25

371

[Distribution of polycyclic aromatic hydrocarbons in water and sediment from Zhoushan coastal area, China].  

PubMed

The spatial and temporal distribution of 16 polycyclic aromatic hydrocarbons (PAHs) has been investigated in water and sediments of Zhoushan coastal area every two months in 2012. The concentrations of total PAHs ranged from 382.3 to 816.9 ng x L(-1), with the mean value of 552.5 ng x L(-1) in water; whereas it ranged from 1017.9 to 3047.1 ng x g(-1), with the mean value of 2 022.4 ng x g(-1) in sediment. Spatial distribution showed that Yangshan and Yanwoshan offshore area had the maximum and minimum of total PAHs contents in water, while the maximum and minimum occurred at Yangshan and Zhujiajian Nansha offshore area in sediment. Temporal distribution revealed that total PAHs contents in water reached the maximum and minimum values in October and June, however in sediments these values were found in August and June, respectively. The PAHs pollution was affected by oil emission, charcoal and coal combustion. Using the biological threshold and exceeded coefficient method to assess the ecological risk of PAHs in Zhoushan coastal area, the result showed that sigma PAHs had a lower probability of potential risk, while there was a higher probability of potential risk for acenaphthylene monomer, and there might be ecological risk for acenaphthene and fluorene. Distribution of PAHs between sediment and water showed that Zhoushan coastal sediment enriched a lot of PAHs, meanwhile the enrichment coefficient (K(d) value) of sediment in Daishan island was larger than that in Zhoushan main island. PMID:25244854

Jiang, Min; Tuan, Le Huy; Mei, Wei-Ping; Ruan, Hui-Hui; Wu, Hao

2014-07-01

372

Variations in the abundance and identity of class II aromatic ring-hydroxylating dioxygenase genes in groundwater at an aromatic hydrocarbon-contaminated site.  

PubMed

The abundance of genes encoding aromatic ring-hydroxylating dioxygenases (RHDs) in the groundwater at an aromatic hydrocarbon-contaminated landfill near Sydney, Australia, was determined by quantitative DNA-DNA hybridization using class II RHD genes as probes. There were marked differences in hybridization signal intensity against DNA extracted from the groundwater at seven different locations across this heterogeneous site. This was interpreted as indicating variation in RHD gene abundance. Clone libraries of polymerase chain reaction (PCR)-amplified RHD gene fragments were constructed from DNA from each of the groundwater samples. The libraries from the samples with greater RHD gene abundance were dominated by a group of bacterial class II RHD genes, designated the S-cluster, that has yet to be found in cultured isolates. These groundwater samples contained no detectable petroleum hydrocarbons. A second group of class II RHD gene sequences, designated the T-cluster, dominated RHD gene clone libraries prepared from groundwater samples that contained detectable levels of total petroleum and aromatic hydrocarbons but lower RHD gene abundance. The hosts and in situ expression of these novel genes, and the substrates of the enzymes they encode, remain unknown. The scarcity of genes from known aromatic hydrocarbon-degrading bacteria and the numerical dominance of the novel genes suggest that the hosts of these novel genes may play an important role in aromatic hydrocarbon degradation at this site. PMID:15643944

Taylor, Paul M; Janssen, Peter H

2005-01-01

373

The effect of strain rate on polycyclic aromatic hydrocarbon (PAH) formation in acetylene diffusion flames  

SciTech Connect

Acetylene is a ubiquitous combustion intermediate that is also believed to be the major precursor for aromatic, polycyclic aromatic hydrocarbon (PAH), and soot formation in both hydrocarbon and halogenated hydrocarbon flames. However, in spite of its important role as a flame intermediate, the detailed chemical structures of acetylene diffusion flames have not been studied in the past. Here the detailed chemical structures of counterflow diffusion flames of acetylene at strain rates of 37.7 and 50.3 s{sup -1} are presented. Both flames possessed the same carbon density of 0.37 g/L corresponding to an acetylene mole fraction of 0.375 in argon on the fuel side, and an oxygen mole fraction of 0.22 in argon on the oxidizer side. Concentration profiles of a large number of major, minor, and trace species, including a wide spectrum of aromatics and PAH, have been determined by direct sampling from flames using a heated quartz microprobe coupled to an online gas chromatograph/mass selective detector (GC/MSD). Temperature profiles were made using a thermocouple and the rapid insertion technique. Although the major species concentrations were nearly the same in the two flames, the mole fraction profiles of trace combustion by-products were significantly lower in the higher-strain-rate flame, by nearly two orders of magnitude for PAH. These comparative results provide new information on the trace chemistries of acetylene flames and should be useful for the development and validation of detailed chemical kinetic mechanisms describing the formation of toxic by-products in the combustion of hydrocarbons and halogenated hydrocarbons. (author)

Yamamoto, Manabu; Duan, Shici; Senkan, Selim [Department of Chemical Engineering, University of California, Los Angeles, CA 90095 (United States)

2007-11-15

374

Aromatic hydrocarbon emissions in the United States deduced from tall tower measurements  

NASA Astrophysics Data System (ADS)

Aromatic compounds including benzene (C6H6), toluene (C7H8), and xylenes (C8H10) are important anthropogenic precursors of secondary organic aerosol and ground-level ozone. In addition, benzene has been classified as a Group 1 carcinogen by the International Agency for Research on Cancer (IARC). However, their emissions remain poorly constrained. Here we present a full year (2011) of continuous aromatic hydrocarbon measurements by PTR-MS at the University of Minnesota tall tower Tracer Gas Observatory (KCMP tall tower, 244 m a.g.l, 44.689°N, 93.073°W). We interpret the tall tower data with a 0.5° ×0.667° GEOS-Chem nested grid simulation to constrain US sources of benzene, toluene, and xylenes. The tall tower observations reveal a clear high bias in the model, with model: measurement slopes of 1.8, 5.3, and 2.9 for benzene, toluene, and xylenes, respectively. The high bias reflects an overestimate of aromatic hydrocarbon emissions in the model, which are based on the RETRO emission Inventory. In this work, we employ a Bayesian inversion to interpret the KCMP tall tower measurements in terms of quantitative constraints on US aromatic sources and the importance of sectors such as on-road transportation, waste treatment and disposal, solvent use, etc. We discuss our findings relative to other emission estimates (e.g., the EPA NEI) and in terms of their implications for air quality modeling.

Hu, L.; Millet, D. B.; Griffis, T. J.; Tessum, C.; Travis, K.

2013-12-01

375

Does the concept of Clar's aromatic sextet work for dicationic forms of polycyclic aromatic hydrocarbons?--testing the model against charged systems in singlet and triplet states.  

PubMed

The concept of Clar's ?-electron aromatic sextet was tested against a set of polycyclic aromatic hydrocarbons in neutral and doubly charged forms. Systems containing different types of rings (in the context of Clar's concept) were chosen, including benzene, naphthalene, anthracene, phenanthrene and triphenylene. In the case of dicationic structures both singlet and triplet states were considered. It was found that for singlet state dicationic structures the concept of aromatic sextet could be applied and the local aromaticity could be discussed in the context of that model, whereas in the case of triplet state dicationic structures Clar's model rather failed. Different aromaticity indices based on various properties of molecular systems were applied for the purpose of the studies. The discussion about the interdependence between the values of different aromaticity indices applied to neutral and charged systems in singlet and triplet states is also included. PMID:21614377

Dominikowska, Justyna; Palusiak, Marcin

2011-07-01

376

Monocyclic aromatic hydrocarbon degradation by Rhodococcus sp. strain DK17.  

PubMed

Rhodococcus sp. strain DK17 was isolated from soil and analyzed for the ability to grow on o-xylene as the sole carbon and energy source. Although DK17 cannot grow on m- and p-xylene, it is capable of growth on benzene, phenol, toluene, ethylbenzene, isopropylbenzene, and other alkylbenzene isomers. One UV-generated mutant strain, DK176, simultaneously lost the ability to grow on o-xylene, ethylbenzene, isopropylbenzene, toluene, and benzene, although it could still grow on phenol. The mutant strain was also unable to oxidize indole to indigo following growth in the presence of o-xylene. This observation suggests the loss of an oxygenase that is involved in the initial oxidation of the (alkyl)benzenes tested. Another mutant strain, DK180, isolated for the inability to grow on o-xylene, retained the ability to grow on benzene but was unable to grow on alkylbenzenes due to loss of a meta-cleavage dioxygenase needed for metabolism of methyl-substituted catechols. Further experiments showed that DK180 as well as the wild-type strain DK17 have an ortho-cleavage pathway which is specifically induced by benzene but not by o-xylene. These results indicate that DK17 possesses two different ring-cleavage pathways for the degradation of aromatic compounds, although the initial oxidation reactions may be catalyzed by a common oxygenase. Gas chromatography-mass spectrometry and 300-MHz proton nuclear magnetic resonance spectrometry clearly show that DK180 accumulates 3,4-dimethylcatechol from o-xylene and both 3- and 4-methylcatechol from toluene. This means that there are two initial routes of oxidation of toluene by the strain. Pulsed-field gel electrophoresis analysis demonstrated the presence of two large megaplasmids in the wild-type strain DK17, one of which (pDK2) was lost in the mutant strain DK176. Since several other independently derived mutant strains unable to grow on alkylbenzenes are also missing pDK2, the genes encoding the initial steps in alkylbenzene metabolism (but not phenol metabolism) appear to be present on this approximately 330-kb plasmid. PMID:12089003

Kim, Dockyu; Kim, Young-Soo; Kim, Seong-Ki; Kim, Si Wouk; Zylstra, Gerben J; Kim, Young Min; Kim, Eungbin

2002-07-01

377

Sources, distribution, and water column processes of aliphatic and polycyclic aromatic hydrocarbons in the northwestern Black Sea water  

Microsoft Academic Search

Aliphatic and aromatic hydrocarbons have been determined in suspended particulate matter collected at subsurficial seawater and three vertical profiles in a transect from the continental shelf, slope, and deep basin of the western Black Sea. The dissolved phase was collected at subsurficial and in the redoxcline. The highest concentrations of hydrocarbons were detected in the Danube, Dnieper, and Dniester River

Cristina Maldonado; Josep M. Bayona; Laurent Bodineau

1999-01-01

378

Determination of petroleum hydrocarbons and polycyclic aromatic hydrocarbons in sludge from wastewater treatment basins.  

PubMed

Screening by gas chromatography with flame ionization detection and gas chromatography-mass spectrometry has been carried out on sludge extracts of wastewater treatment basins. Soxhlet extraction with trichlorotrifluoroethane was applied. The yields for petroleum hydrocarbons and PAH recovery were high, usually in excess of 90%. The proposed investigations permit a quick assessment of petroleum pollutants in the environment. PMID:12729275

Pavlova, A; Ivanova, R

2003-04-01

379

Sorption coefficients of polycyclic aromatic hydrocarbons for two lake sediments: Influence of the bactericide sodium azide  

SciTech Connect

Sorption coefficient s (K{sub p}s) of a series of polycyclic aromatic hydrocarbons (PAHs) were determined in two Dutch freshwater lake sediments to improve the insight into sorption in the aquatic environment. The influence of experimental factors, such as compound concentration, equilibration time, and influence of a bactericide on K{sub p}, was studied. No significant influence of compound concentration on K{sub p} was found. A contact time of 48 h was sufficient to reach equilibrium between PAHs in the sediment and water phase. In the absence of the bactericide, sodium azide, incomplete mass balances, and high K{sub p} of low molecular weight PAHs were found that were not caused by volatilization from, photodegradation in, or sorption by the test system. In the presence of sodium azide, however, high mass balances and lower K{sub p} were found for these compounds. This suggested that significant biodegradation of these compounds occurred in the water phase in the absence of sodium azide. The organic carbon-normalized sorption coefficients (K{sub oc}) of the PAHs in Lake Oostvaardersplassen were two to three times higher than those in Lake Ketelmeer sediment. Although K{sub oc} of the PAHs differed for the two sediments, a clear relationship was found between K{sub oc} and the octanol/water partition coefficient for both sediments and between the K{sub oc} of both sediments. In conclusion, the methodology to determine K{sub p} of biodegradable compounds should include the prevention of bacterial activity, e.g., by addition of sodium azide. Sorption of PAHs in the Dutch lake sediments is determined by the hydrophobicity of the PAH, the organic carbon content of the sediment, and one or more unspecified sediment-specific characteristics.

Maagd, P.G.J. de; Sinnige, T.L. [Utrecht Univ. (Netherlands). RITOX-Environmental Chemistry Group; Schrap, S.M. [RIZA, Lelystad (Netherlands). Inst. for Inland Water Management and Waste Water Treatment; Opperhuizen, A.; Sijm, D.T.H.M. [National Inst. for Public Health and Environment, Bilthoven (Netherlands)

1998-10-01

380

Residual indoor contamination from world trade center rubble fires as indicated by polycyclic aromatic hydrocarbon profiles.  

PubMed

The catastrophic destruction of the World Trade Center (WTC) on Sept. 11, 2001 (9/11) created an immense dust cloud followed by fires that emitted smoke and soot into the air of New York City (NYC) well into December. Outdoor pollutant levels in lower Manhattan returned to urban background levels after about 200 days as the fires were put out and the debris cleanup was completed. However, particulate matter (PM) from the original collapse and fires also penetrated into commercial and residential buildings. This has created public concern because WTC dust is thought to cause adverse pulmonary symptoms including "WTC cough" and reduced lung capacity. Additionally, some recent studies have suggested a possible link between exposure to WTC contamination and other adverse health effects. Distinguishing between normal urban pollutant infiltration and residual WTC dust remaining in interior spaces is difficult; efforts are underway to develop such discriminator methods. Some progress has been made in identifying WTC dust by the content of fibers believed to be associated with the initial building collapse. There are also contaminants created by the fires that burned for 100 days in the debris piles of the building rubble. Using WTC ambient air samples, we have developed indicators for fire related PM based on the relative amounts of specific particle bound polycyclic aromatic hydrocarbons (PAHs) and the mass fraction of PAHs per mass of PM. These two parameters are combined, and we show a graphical method for discriminating between fire sources and urban particulate sources as applied to samples of settled dusts. We found that our PAHs based discriminator method can distinguish fire source contributions to WTC related particulate matter and dusts. Other major building fires or large open burn events could have similar PAHs characteristics. We found that random samples collected approximately 3.5 years after the WTC event from occupied indoor spaces (primarily residential) in the New York area are not statistically distinguishable from contemporary city background. PMID:16572771

Pleil, Joachim D; Funk, William E; Rappaport, Stephen M

2006-02-15

381

Determination of polycyclic aromatic hydrocarbons in alcoholic drinks and the identification of their potential sources.  

PubMed

Some polycyclic aromatic hydrocarbons (PAHs), particularly those with a high molecular mass, have been classified as probably being carcinogenic to humans by the International Agency for Research on Cancer (IARC). The significance of the determination of PAHs is reflected by the special attention the European Union is paying to regulating their maximum allowed levels in various types of foodstuffs. Like tobacco and smoked meats, alcoholic drinks can also contain these carcinogenic chemicals, as the latter have been detected in the charred insides of barrels, some ingredients such as caramel or the smoke released during the drying of germinated barley in beer or whisky. This paper determined the contents of seven PAHs in alcoholic beverages of variable alcoholic strength that had been aged in charred barrels for different times (months, years). The aim was to elucidate the dependence of the formation of seven PAHs on the type of charring (traditional or convective) used and the charring intensity (light, medium or heavy). Based on the results, the way the tree raw material is toasted strongly influences PAH levels in alcoholic drinks; thus, traditional charring produces increased amounts of PAHs from the wood relative to convective toasting. The sum of the analysed PAH concentrations in the aged alcoholic beverages studied ranged from zero for a white wine to 172 ng l(-1) for a 'brandy de jerez solera'. The carcinogenic indicator benzo[a]pyrene was found at concentrations below 10 ng l(-1). These PAH concentrations in alcoholic beverages are very low relative to those in smoked and char-broiled foodstuffs. Any health hazards, however, can be minimized by using convective toasting to manufacture the barrels where the drinks are to be aged. PMID:16192065

García-Falcón, M S; Simal-Gándara, J

2005-09-01

382

Seasonal variation of polycyclic aromatic hydrocarbon exposure levels in Mexico City.  

PubMed

This work presents the results obtained when determining the priority polycyclic aromatic hydrocarbon (PAH) concentration contained in particulate matter 10 microm in aerodynamic diameter or less (PM10) and in the gas phase in Mexico City's atmosphere by means of a field study conducted during 2005. PM10 and vapor-phase PAHs were collected on prebaked quartz fiber filters and PUF-XAD-4 resin and quantified by gas chromatography (GC)-mass spectrometry. Vapor-phase PAHs comprised 86-97% of the total PAH mass, and naphthalene was the most abundant PAH determined, contributing 84-93% to the total mass. The benzo[a]pyrene content was on average 7% of the PAHs' particle phase and 0.2-1% of the gas phase. The PAH concentrations measured where large industrial areas are located were 2-8 times greater during the fall/winter months (dry-cold season), when winds bear north- northeasterly, than in spring and summer. In contrast, the largest partition gas/particle ratio occurred during the dry-warm season (March-May). The results of statistical analysis using multivariate techniques suggest that motor vehicles are the main PAH contributors. The toxicity equivalence factors (TEFs) related to the carcinogenic benzo[a]pyrene potency were used for the assessment of the carcinogenic potential risk because of the measured airborne PAHs. Benzo[a]pyrene equivalent (BAPeq) concentrations were determined through multiplication of the individual PAH concentrations by their corresponding TEF value. The estimated total BAPeq for the whole field study considering only PM10 PAHs was 1085 pg m(-3). However, when taking into account the PAHs in both phases, the estimated total BAPeq was 1250 pg m(-3); in either case, the values were greater than the 1000-pg m(-3) limit proposed by European countries. PMID:20480854

Mugica, Violeta; Hernández, Sara; Torres, Miguel; García, Rocio

2010-05-01

383

The phn Island: A New Genomic Island Encoding Catabolism of Polynuclear Aromatic Hydrocarbons  

PubMed Central

Bacteria are key in the biodegradation of polycyclic aromatic hydrocarbons (PAH), which are widespread environmental pollutants. At least six genotypes of PAH degraders are distinguishable via phylogenies of the ring-hydroxylating dioxygenase (RHD) that initiates bacterial PAH metabolism. A given RHD genotype can be possessed by a variety of bacterial genera, suggesting horizontal gene transfer (HGT) is an important process for dissemination of PAH-degrading genes. But, mechanisms of HGT for most RHD genotypes are unknown. Here, we report in silico and functional analyses of the phenanthrene-degrading bacterium Delftia sp. Cs1-4, a representative of the phnAFK2 RHD group. The phnAFK2 genotype predominates PAH degrader communities in some soils and sediments, but, until now, their genomic biology has not been explored. In the present study, genes for the entire phenanthrene catabolic pathway were discovered on a novel ca. 232?kb genomic island (GEI), now termed the phn island. This GEI had characteristics of an integrative and conjugative element with a mobilization/stabilization system similar to that of SXT/R391-type GEI. But, it could not be grouped with any known GEI, and was the first member of a new GEI class. The island also carried genes predicted to encode: synthesis of quorum sensing signal molecules, fatty acid/polyhydroxyalkanoate biosynthesis, a type IV secretory system, a PRTRC system, DNA mobilization functions and >50 hypothetical proteins. The 50% G?+?C content of the phn gene cluster differed significantly from the 66.7% G?+?C level of the island as a whole and the strain Cs1-4 chromosome, indicating a divergent phylogenetic origin for the phn genes. Collectively, these studies added new insights into the genetic elements affecting the PAH biodegradation capacity of microbial communities specifically, and the potential vehicles of HGT in general. PMID:22493593

Hickey, William J.; Chen, Shicheng; Zhao, Jiangchao

2012-01-01

384

Polycyclic aromatic hydrocarbons and nitropolycyclic aromatic hydrocarbons in urban air particulates and their relationship to emission sources in the Pan-Japan Sea countries  

NASA Astrophysics Data System (ADS)

Airborne particulates were collected in seven cities in the Pan-Japan Sea countries, Shenyang (China), Vladivostok (Russia), Seoul (South Korea), Kitakyushu, Kanazawa, Tokyo and Sapporo (Japan), in winter and summer from 1997 to 2002. In addition, particulates from domestic coal-burning heaters and diesel engine automobiles were collected in Shenyang and Kanazawa, respectively. Nine polycyclic aromatic hydrocarbons (PAHs) and four nitropolycyclic aromatic hydrocarbons (NPAHs) in the extracts from the particulates were analysed by HPLC with fluorescence and chemiluminescence detections, respectively. The PAHs were fluoranthene, pyrene (Pyr), benz[ a]anthracene, chrysene, benzo[ b]fluoranthene, benzo[ k]fluoranthene, benzo[ a]pyrene, benzo[ ghi]perylene and indeno[1,2,3- cd]pyrene, and NPAHs were 1,3-, 1,6-, 1,8-dinitropyrenes, and 1-nitropyrene (1-NP). Mean atmospheric concentrations of PAHs in Shenyang and Vladivostok were substantially higher than those in Seoul, Tokyo, Sapporo, Kitakyushu and Kanazawa. However, the mean atmospheric concentrations of NPAHs were at the same levels in all cities except Kitakyushu. The expected seasonal variations (greater PAH and NPAH concentrations in winter than in summer) were observed in all cities. In order to study the major contributors of atmospheric PAHs and NPAHs, both cluster analysis and factor analysis were used and three large clusters were identified. Furthermore, the concentration ratios of 1-NP to Pyr were significantly smaller in Shenyang, Vladivostok and Kitakyushu and the values were close to those observed in particulates from coal stove exhaust. By contrast, in Seoul, Kanazawa, Tokyo and Sapporo the [1-NP]/[Pyr] ratio reached values similar to those of particulates released from diesel-engine automobiles. The [1-NP]/[Pyr] concentration ratio seemed to be a suitable indicator of the contribution made by diesel-engine vehicles and coal combustion to urban air particulates.

Tang, Ning; Hattori, Tetsuyuki; Taga, Rina; Igarashi, Kazuhiko; Yang, Xiaoyang; Tamura, Kenji; Kakimoto, Hitoshi; Mishukov, Vasiliy F.; Toriba, Akira; Kizu, Ryoichi; Hayakawa, Kazuichi

385

Graphene etching on SiC grains as a path to interstellar polycyclic aromatic hydrocarbons formation.  

PubMed

Polycyclic aromatic hydrocarbons as well as other organic molecules appear among the most abundant observed species in interstellar space and are key molecules to understanding the prebiotic roots of life. However, their existence and abundance in space remain a puzzle. Here we present a new top-down route to form polycyclic aromatic hydrocarbons in large quantities in space. We show that aromatic species can be efficiently formed on the graphitized surface of the abundant silicon carbide stardust on exposure to atomic hydrogen under pressure and temperature conditions analogous to those of the interstellar medium. To this aim, we mimic the circumstellar environment using ultra-high vacuum chambers and investigate the SiC surface by in situ advanced characterization techniques combined with first-principles molecular dynamics calculations. These results suggest that top-down routes are crucial to astrochemistry to explain the abundance of organic species and to uncover the origin of unidentified infrared emission features from advanced observations. PMID:24448250

Merino, P; Švec, M; Martinez, J I; Jelinek, P; Lacovig, P; Dalmiglio, M; Lizzit, S; Soukiassian, P; Cernicharo, J; Martin-Gago, J A

2014-01-01

386

Leaching of polycyclic aromatic hydrocarbons from oil shale processing waste deposit: a long-term field study.  

PubMed

The leaching behavior of selected polycyclic aromatic hydrocarbons (PAHs) from an oil shale processing waste deposit was monitored during 2005-2009. Samples were collected from the deposit using a special device for leachate sampling at field conditions without disturbance of the upper layers. Contents of 16 priority PAHs in leachate samples collected from aged and fresh parts of the deposit were determined by GC-MS. The sum of the detected PAHs in leachates varied significantly throughout the study period: 19-315 ?g/l from aged spent shale, and 36-151 ?g/l from fresh spent shale. Among the studied PAHs the low-molecular weight compounds phenanthrene, naphthalene, acenaphthylene, and anthracene predominated. Among the high-molecular weight PAHs benzo[a]anthracene and pyrene leached in the highest concentrations. A spent shale deposit is a source of PAHs that could infiltrate into the surrounding environment for a long period of time. PMID:24631927

Jefimova, Jekaterina; Irha, Natalya; Reinik, Janek; Kirso, Uuve; Steinnes, Eiliv

2014-05-15

387

Persistence of polycyclic aromatic hydrocarbons in sediments in the deeper area of the Northern Adriatic Sea (Mediterranean Sea).  

PubMed

The Po Valley is the most important agricultural and industrial area of Adriatic basin. In this area there are several rivers which transport polycyclic aromatic hydrocarbons (PAHs) into the sea via suspended particulate matter. This study describes the persistence of PAHs in the deep and coastal sediments of the Northern Adriatic. Different environmental conditions were studied: salinity, temperature, sunlight, sediment particle size and organic matter in sediment. The average conditions in the deep areas of the Northern Adriatic are: salinity higher than 37, temperature lower than 11 °C, darkness and clayey sediments with a high organic matter content. These conditions increase the persistence of the PAHs in the deep area of the Northern Adriatic. PMID:23127723

Marini, Mauro; Frapiccini, Emanuela

2013-02-01

388

Polycyclic aromatic hydrocarbons in soils and lower-layer plants of the southern shrub tundra under technogenic conditions  

NASA Astrophysics Data System (ADS)

In soils and plants of the southern shrub tundra, 15 polycyclic aromatic hydrocarbons (PAHs) have been detected by high-performance liquid chromatography. Polyarenes in emissions, soil organic horizons, and plants mainly include low-molecular-weight PAHs: naphthalene, fluorine, and pyrene. The contents of the total PAHs in soils and plants exceed the background levels by 3-5 times. The distribution of polyarenes among the organs of the studied plants is nonuniform and depends on the plant species and technogenic load on the area. The studied plants include both hyperaccumulators of polyarenes ( Pleurozium schreberi) and indicators of PAHs in the soil ( Polytrichum commune). Pleurozium schreberi is the most abundant species in the areas under study, and it accumulates the largest mass fraction of PAHs. The differences in the accumulation of PAHs by the plants of the tundra and taiga zones have been revealed.

Yakovleva, E. V.; Gabov, D. N.; Beznosikov, V. A.; Kondratenok, B. M.

2014-06-01

389

Parameters describing nonequilibrium transport of polycyclic aromatic hydrocarbons through contaminated soil columns: Estimability analysis, correlation, and optimization  

NASA Astrophysics Data System (ADS)

The soil and groundwater at former industrial sites polluted by polycyclic aromatic hydrocarbons (PAHs) produce a very challenging environmental issue. The description of PAH transport by means of mathematical models is therefore needed for risk assessment and remediation strategies at these sites. Due to the complexity of release kinetics and transport behavior of the PAHs in the aged contaminated soils, their transport is usually evaluated at the laboratory scale. Transport parameters are then estimated from the experimental data via the inverse method. To better assess the uncertainty of optimized parameters, an estimability method was applied to firstly investigate the information content of experimental data and the possible correlations among parameters in the two-site sorption model. These works were based on the concentrations of three PAHs, Acenaphthene (ACE), Fluoranthene (FLA) and Pyrene (PYR), in the leaching solutions of the experiments under saturated and unsaturated flow conditions.

Ngo, Viet V.; Michel, Julien; Gujisaite, Valérie; Latifi, Abderrazak; Simonnot, Marie-Odile

2014-03-01

390

Immunosuppressive potential of several polycyclic aromatic hydrocarbons (PAHs) found at a Superfund site: new model used to evaluate additive interactions between benzo[ a]pyrene and TCDD  

Microsoft Academic Search

Exposure to environmental pollution is rarely limited to a single compound or even a single class of compounds. The Superfund site located in Massena, NY, is contaminated by both halogenated aromatic hydrocarbons (HAHs) and polycyclic aromatic hydrocarbons (PAHs). Since representatives of both HAHs and PAHs are capable of binding to the aromatic hydrocarbon receptor (AhR), two well-documented AhR-mediated effects, immunosuppression

J. B. Silkworth; T. Lipinskas; C. R. Stoner

1995-01-01

391

Reflectance spectroscopy (350-2500 nm) of solid-state polycyclic aromatic hydrocarbons (PAHs)  

NASA Astrophysics Data System (ADS)

Polycyclic aromatic hydrocarbons (PAHs) are organic compounds based on fused aromatic rings, and are formed in a variety of astrophysical, solar nebula and planetary processes. Polycyclic aromatic hydrocarbons are known or suspected to occur in a wide variety of planetary settings including icy satellites, Titan’s hazes, carbonaceous meteorites, comet nuclei, ring particles; and terrestrial organic-rich lithologies such as coals, asphaltites, and bituminous sands. Relatively few measurements of the visible and near-infrared spectra of PAHs exist, yet this wavelength region (350-2500 nm) is widely used for remote sensing. This study presents detailed analyses of the 350-2500 nm reflectance spectra of 47 fine-grained powders of different high-purity solid-state PAHs. Spectral properties of PAHs change with variations in the number and connectivity of linked aromatic rings and the presence and type of side-groups and heterocycles. PAH spectra are characterized by three strong features near ?880 nm, ?1145 nm, and ?1687 nm due to overtones of ?CH fundamental stretching vibrations. Some PAHs are amenable to remote detection due to the presence of diagnostic spectral features, including: Nsbnd H stretching overtones at 1490-1515 nm in NH- and NH2-bearing PAHs, aliphatic or saturated bond Csbnd H overtone vibrations at ?1180-1280 nm and ?1700-1860 nm; a broad asymmetric feature between ?1450 nm and ?1900 nm due to Osbnd H stretching overtones in aromatic alcohols, Csbnd H and Cdbnd O combinations near ?2000-2010 nm and ?2060-2270 nm in acetyl and carboxyl-bearing PAHs. Other substituents such as sulphonyl, thioether ether and carboxyl heterocycles, or cyano, nitrate, and aromatic side groups, do not produce well-resolved diagnostic spectral features but do cause shifts in the positions of the aromatic Csbnd H vibrational overtone features. Fluorescence is commonly suppressed by the presence of heterocycles, side-groups and in many non-alternant PAHs. The spectral characteristics of PAHs offer the potential, under suitable circumstances, for remote characterization of the classes of PAH present and in some cases, identification of particular heterocyclic or side-group substituents.

Izawa, M. R. M.; Applin, D. M.; Norman, L.; Cloutis, E. A.

2014-07-01

392

C-H and N-H bond dissociation energies of small aromatic hydrocarbons  

SciTech Connect

A survey of computational methods was undertaken to calculate the homolytic bond dissociation energies (BDEs) of the C-H and N-H bonds in monocyclic aromatic molecules that are representative of the functionalities present in coal. These include six-membered rings (benzene, pyridine, pyridazine, pyrimidine, pyrazine) and five-membered rings (furan, thiophene, pyrrole, oxazole). By comparison of the calculated C-H BDEs with the available experimental values for these aromatic molecules, the B3LYP/6-31G(d) level of theory was selected to calculate the BDEs of polycyclic aromatic hydrocarbons (PAHs), including carbonaceous PAHs (naphthalene, anthracene, pyrene, coronene) and heteroatomic PAHs (benzofuran, benzothiophene, indole, benzoxazole, quinoline, isoquinoline, dibenzofuran, carbazole). The cleavage of a C-H or a N-H bond generates a {sigma} radical that is, in general, localized at the site from which the hydrogen atom was removed. However, delocalization of the unpaired electron results in {approximately} 7 kcal {center{underscore}dot} mol{sup {minus}1} stabilization of the radical with respect to the formation of phenyl when the C-H bond is adjacent to a nitrogen atom in the azabenzenes. Radicals from five-membered rings are {approximately} 6 kcal {center{underscore}dot} mol{sup {minus}1} less stable than those formed from six-membered rings due to both localization of the spin density and geometric factors. The location of the heteroatoms in the aromatic ring affects the C-H bond strengths more significantly than does the size of the aromatic network. Therefore, in general, the monocyclic aromatic molecules can be used to predict the C-H BDE of the large PAHs within 1 kcal {center{underscore}dot} mol{sup {minus}1}.

Barckholtz, C.; Barckholtz, T.A.; Hadad, C.M.

1999-01-27

393

Simultaneous removal of sulfur dioxide and polycyclic aromatic hydrocarbons from incineration flue gas using activated carbon fibers.  

PubMed

Incineration flue gas contains polycyclic aromatic hydrocarbons (PAHs) and sulfur dioxide (SO2). The effects of SO2 concentration (0, 350, 750, and 1000 ppm), reaction temperature (160, 200, and 280 degrees C), and the type of activated carbon fibers (ACFs) on the removal of SO2 and PAHs by ACFs were examined in this study. A fluidized bed incinerator was used to simulate practical incineration flue gas. It was found that the presence of SO2 in the incineration flue gas could drastically decrease removal of PAHs because of competitive adsorption. The effect of rise in the reaction temperature from 160 to 280 degrees C on removal of PAHs was greater than that on SO2 removal at an SO2 concentration of 750 ppm. Among the three ACFs studied, ACF-B, with the highest microporous volume, highest O content, and the tightest structure, was the best adsorbent for removing SO2 and PAHs when these gases coexisted in the incineration flue gas. Implications: Simultaneous adsorption of sulfur dioxide (SO2) and polycyclic aromatic hydrocarbons (PAHs) emitted from incineration flue gas onto activated carbon fibers (ACFs) meant to devise a new technique showed that the presence of SO2 in the incineration flue gas leads to a drastic decrease in removal of PAHs because of competitive adsorption. Reaction temperature had a greater influence on PAHs removal than on SO2 removal. ACF-B, with the highest microporous volume, highest O content, and tightest structure among the three studied ACFs, was found to be the best adsorbent for removing SO2 and PAHs. PMID:25283001

Liu, Zhen-Shu; Li, Wen-Kai; Hung, Ming-Jui

2014-09-01

394

ORIGIN OF ORGANIC GLOBULES IN METEORITES: LABORATORY SIMULATION USING AROMATIC HYDROCARBONS  

SciTech Connect

Analogs of organic hollow globules, which have been found in carbonaceous chondrite meteorites and interplanetary dust particles, were synthesized in our laboratory from benzene and anthracene using plasma. Our results suggest that organic globules could be made from aromatic rings in circumstellar envelopes around evolved stars. The hollow interior could be formed by coagulation of vacancies, formed by electronic excitation and/or knock-out of carbon atoms following irradiation by plasma particles such as protons and He{sup +} ions. This experimental result suggests that organic globules are possibly the final products in the evolution of carbonaceous matter from acetylene and benzene to polycyclic aromatic hydrocarbons in ejecta gas from evolved stars.

Saito, Midori [Institute for Molecular Science, National Institutes of Natural Sciences, Okazaki, Aichi 444-8585 (Japan); Kimura, Yuki [Department of Earth and Planetary Materials Science, Graduate School of Science, Tohoku University, Sendai 980-8578 (Japan)

2009-10-01

395

Sorption of polycyclic aromatic hydrocarbons (PAHs) to lignin: effects of hydrophobicity and temperature.  

PubMed

The study of the sorption of contaminants to lignin is significant for understanding the migration of contaminants in the environment as well as developing low cost sorbent. In this study, sorption of three polycyclic aromatic hydrocarbons (PAHs), naphthalene, acenaphthene and phenanthrene, to lignin was investigated. Sorption isotherms were well described by both linear and Freundlich sorption models. Sorption coefficients of PAHs to lignin from water obtained from regression of both linear model (K d) and Freundlich model (K f) were highly positively correlated with hydrophobicity of PAHs. The amorphous structure of lignin provided sufficient sorption domain for partitioning of PAHs, and the attraction between PAHs molecules and aromatic fractions in lignin via ?-? electron-donor-acceptor (?-? EDA) interaction is hypothesized to provide a strong sorption force. Thermodynamic modeling revealed that sorption of PAHs to lignin was a spontaneous and exothermic process. PMID:24838935

Zhang, Ming; Ahmad, Mahtab; Lee, Sang Soo; Xu, Li Heng; Ok, Yong Sik

2014-07-01

396

Friction of iron lubricated with aliphatic and aromatic hydrocarbons and halogenated analogs  

NASA Technical Reports Server (NTRS)

The influence of oxygen and various organic molecules on the reduction of the friction of an iron (011) single crystal surface was investigated. A comparison was made between aliphatic and aromatic structures, all of which contained six carbon atoms, and among various halogen atoms. Results of the investigation indicate that hexane and benzene give similar friction coefficients over a range of loads except at very light loads. At light loads, the friction decreased with an increase in the load where the halogens fluorine and chlorine are incorporated into the benzene molecular structure; however, over the same load range when bromine and iodine were present, the friction was relatively unchanged. The aliphatic compound chlorohexane exhibited lower friction coefficients than the aromatic structure chlorobenzene at very light loads. With the brominated benzene structures, however, friction was essentially the same. Oxygen was more effective in reducing friction than were the simple hydrocarbons.

Buckley, D. H.

1976-01-01

397

Polycyclic Aromatic Hydrocarbons with Armchair Edges and the 12.7 ?m Band  

NASA Astrophysics Data System (ADS)

In this Letter, we report the results of density functional theory calculations on medium-sized neutral polycyclic aromatic hydrocarbon (PAH) molecules with armchair edges. These PAH molecules possess strong C-H stretching and bending modes around 3 ?m and in the fingerprint region (10-15 ?m), and also strong ring deformation modes around 12.7 ?m. Perusal of the entries in the NASA Ames PAHs Database shows that ring deformation modes of PAHs are common, although generally weak. Therefore, we propose that armchair PAHs with NC > 65 are responsible for the 12.7 ?m aromatic infrared band in H II regions and discuss the astrophysical implications in the context of the PAH life cycle.

Candian, A.; Sarre, P. J.; Tielens, A. G. G. M.

2014-08-01

398

Molecular and isotopic evidence for fossil fuel aromatic hydrocarbons in soils  

SciTech Connect

The origin of organic molecules occurring in complex media such as soils and sediments is still an enigma. In soils, for example, the occurrence of polycyclic aromatic hydrocarbons (PAH) is a major concern because these potentially toxic compounds may ultimately be transferred into food and drinking water. At present, two main hypotheses can be made for the origin of PAH in soils. PAH, or their precursors, can be synthesized by modem plants, within soil biomass and humic substance degradation. Alternatively, PAH may derive from fossil fuels and associated combustion products. In the present study, soils have been cultivated for 23 years with maize in order to label the organic matter with naturally {sup 13}C-enriched maize-derived carbon. {sup 13}C, {sup 14}C and molecular analysis of aromatic fractions from those soils show that the main part of PAH are ancient, most probably derived from fossil fuel and their combustion products.

Lichtfouse, E. [Pierre and Marie Curie Univ., Paris (France); Budzinski, F.H.; Garrigues, P. [Bordeaux Univ., Talence (France)] [and others

1996-10-01

399

Growth of a lower eukaryote in non-aromatic hydrocarbon media ?C 12 and its exobiological significance  

NASA Astrophysics Data System (ADS)

The fungus termed Fusarium alkanophyllum Palacios-Prü & V. Marcano is able to grow in and degrade several saturated hydrocarbons in the presence of UV radiation at 253.7 nm or 354.5 nm, H 2O 2, and CO 2, with little or no oxygen and with minimum water requirements showing several phenotypes and optimal growth. Further, this species is also able to produce important amounts of metabolic water from the substrate. Therefore, different simulation experiments were done to evaluate the biological, physiological and biochemistry responses taking into account conditions similar to solar and extrasolar environments having various CO 2 contents and occupying the habitable zone around the main sequence stars with spectral types in the F to mid-K range with L ( L/) ˜1. Solar and extrasolar environments similar to those of the jovian satellites and Titan were also considered. Accordingly, the growth of F. alkanophyllum was inhibited in < n-C 10 or aromatic hydrocarbons. The organism is proteolytic, since it grows in culture media of hydrocarbons containing albumin, glycoprotein and gammaglobulin as a source of carbon and nitrogen; however, in media containing other proteins that lack sulphur linkages, no growth was observed. Analysis by electron microscopy (EM) of F. alkanophyllum grown from germinated spores in heavy and light hydrocarbon media in the presence or absence of UV radiation and oxidizing or reducing gases revealed the absence of plasmalemma, nuclear membranes and other cytomembranes as an adaptative response. Aqueous extracts of secreted material from several hydrocarbon cultures analysed by FTIR spectroscopy revealed the presence of fatty acids and UV-protective indole pigments. An additional protection against UV radiation is offered by the hydrocarbon media which have substantial absorbances between 200 and 354 nm. The absence of lipidic membranes in F. alkanophyllum constitute an important finding in the cell biology of the terrestrial species that deserve careful evaluation. The results of this work allows to encourage exobiology experiments utilizing extremophile eukaryotes such as fungi in the International Space Station or on Mars. Moreover, the study of the physiological mechanisms involved in anhydrous conditions must be of interest in the exobiology of solar and extrasolar bodies having hydrocarbon potential niches because it offers an alternative vision related with the search for life in the universe.

Marcano, Vicente; Benitez, Pedro; Palacios-Prü, Ernesto

2002-06-01

400

Polycyclic aromatic hydrocarbons: are they a problem in processed oil shales. [254 references  

SciTech Connect

Organic residues from processed oil shales were characterized with specific attention to polycyclic aromatic hydrocarbons (PAH). Oil shale development in the White River Basin (Utah and Colorado) was projected and hydrological and geological parameters pertinent to estimations of polycyclic aromatic hydrocarbons (PAH) flux were focused. Oil shale samples from the Union B, Paraho, and Tosco II processes were extracted by using organic solvents in a soxhlet apparatus and by mixing shale samples with water (characterization of in situ shales, as mined shales and alluvial samples are also included). Literature reported organic chemistry isolation and identification regimes were summarized in a tabular format. Selected 3 through 6 ring aromatic hydrocarbons were also characterized in a tabular format. More than 100 organic compounds from processed oil shales were identified by gas chromatography coupled with mass spectrometry (GC/MS). Four and 5 ring PAH, i.e., fluoranthrene, pyrene, triphenylene, benz(a)anthracene, chrysene, benzo(e)pyrene, perylene, and benzo(a)pyrene, respectively were found to be benzene extractable from processed shales in concentrations ranging from <1 to >50 ppB (weight of each PAH/weight shale). These PAH were detected in water extracts at levels below their respective solubilities. Preliminary aqueous chlorination studies using selected 3 to 5 ring PAH resulted in reductions of more than 90 percent for anthracene and pyrene after 1 hour of mixing with >10 mg/l free available chlorine at a pH of 8.0 to 8.5. Reductions of phenanthrene, triphenylene, and benz(a)anthracene were only about 15 to 25 percent after 15 hours of mixing. As a best estimate, fluoranthrene and the study 5 ring PAH concentrations were only reduced by about 50 percent in 15 hours. 254 references, 16 figures, 34 tables.

Maase, D.L.; Adams, V.D.

1983-05-01

401

Genotoxicity of nitrated polycyclic aromatic hydrocarbons and related structures on Escherichia coli PQ37 (SOS chromotest)  

SciTech Connect

To determine the genotoxicity of nitrated polycyclic aromatic hydrocarbons and related molecules (nPAH) the authors examined 24 compounds representative of nitroanthracenes, nitrofluorenes, nitronaphthalenes, nitropyrenes, and nitroquinolines for genotoxicity in Escherichia coli PQ37 (SOS-chromotest). To enhance the sensitivity of the tester strain and optimize metabolic activation they used a modified test protocol and S9-mix composition. As expected from previously referred mutagenicity studies, the highest SOS inducing potencies (SOSIP) were exhibited by the dinitropyrenes, 4-nitroquinoline-N-oxide, and 3-nitrofluoranthese. The results were compared to those reported for the bacterial mutagenicity of these substances in Salmonella typhimurium TA98.

Mersch-Sundermann, V.; Kern, S.; Wintermann, F. (Univ. of Heidelberg, Mannheim (West Germany))

1991-01-01

402

Polycyclic aromatic hydrocarbons in ambient air particles in the city of Las Palmas de Gran Canaria  

Microsoft Academic Search

Concentration levels, seasonal variation and winter\\/summer ratios of 11 polycyclic aromatic hydrocarbons (PAHs) in the TSP of Las Palmas de Gran Canaria city were determined. The study area is under the influence of heavy traffic (80,000 vehicles\\/day). Pyr\\/BaA, Pyr\\/Flt, B(ghi)P\\/I(cd)P and B(b+k)F\\/B(ghi)P ratios were calculated; the values of these two last suggest a strong influence of diesel fuel burning. Levels

A. Vera Castellano; J. López Cancio; P. Santana Alemán; J. Santana Rodr??guez

2003-01-01

403

Measurement of particulate phase polycyclic aromatic hydrocarbon (PAHs) around a petroleum refinery.  

PubMed

A study on concentrations of ambient particulates viz. total suspended particulate matters (TSP), respirable suspended particulate matter (RSPM) and polycyclic aromatic hydrocarbons (PAH) were carried out at six sites around the Asia's largest, 12 MMTPA, petroleum refinery in west coast of India. PAH concentrations are correlated with each other in these sites, suggesting that they have related sources and sinks. The present article discusses the monitoring aspects such as sample collection, pretreatment and analytical methods and compares the monitored levels for assessing the source receptor distribution pattern. The main sources of RSPM and PAHs in urban air are automobile exhaust (CPCB, Polycyclic aromatic hydrocarbons (PAHs) in air and their effects on human health. " http://www.cpcb.nic.in/ph/ch21103.htm ", 2003; Manuel et al., Environmental Science and Technology, 13: 227-231, 2004) and industrial emissions like petroleum refinery (Vo-Dinh, Chemical analysis of polycyclic aromatic hydrocarbons, Wiley: New York, 1989; Wagrowaski and Hites, Environmental Science and Technology, 31: 279-282, 1997). Polycyclic aromatic hydrocarbons (PAH) are ubiquitous constituents of urban airborne particulate mostly generated by anthropogenic activities (Li et al., Environmental Science and Technology, 37:1958-2965, 2003; Thorsen et al., Environmental Science and Technology, 38: 2029-2037, 2004; Ohura et al., Environmental Science and Technology, 32: 450-455, 2004) and some of them are of major health concern mainly due to their well-known carcinogenic and mutagenic properties (Soclo et al., Marine Pollution Bulletin, 40: 387-396, 2000; Chen et al., Environment International, 28: 659-668, 2003; Larsen and Baker, Environmental Science and Technology, 32: 450-455, 2003). Limited information is available on PAHs contributions from refineries to ambient air. Hence this study would not only create a database but also provide necessary inputs towards dose-response relationship for fixing standards. Also, since it acts as precursor to green house gas, the data would be useful for climate change assessments. The objective of this article is to find out the concentration of PAHs in particulate matter around petroleum refinery and compare with their concentrations in major Indian urban centers. PMID:17562207

Rao, Padma S; Ansari, M Faiyaz; Pipalatkar, P; Kumar, A; Nema, P; Devotta, S

2008-02-01

404

Biodiversity amongst cultivable polycyclic aromatic hydrocarbon-transforming bacteria isolated from an abandoned industrial site.  

PubMed

The characterisation of a microbial community of a polycyclic aromatic hydrocarbons (PAHs) contaminated site (formerly Carbochimica, Trento, Italy) was carried out. A preliminary evaluation of the heterogeneity and the metabolic activity of the microbial community were attempted by denaturing gradient gel electrophoresis (DGGE) and reverse transcriptase-denaturing gel electrophoresis (RT-DGGE). The presence of a heterogeneous and metabolically active microbial community was found. To evaluate the PAH-transforming potential of the soil bacterial community, enrichment cultures were set up. Taxonomically diverse bacteria, showing different biochemical PAH-transforming pathways were obtained. Some of the isolates showed not nah-homologous PAH-transforming genotypes. PMID:15358423

Zocca, Chiara; Di Gregorio, Simona; Visentini, Filippo; Vallini, Giovanni

2004-09-15

405

Polycyclic aromatic hydrocarbons in food and beverages. Analytical methods and trends.  

PubMed

Polycyclic aromatic hydrocarbons (PAHs) are compounds widespread in the environment, many of them showing carcinogenic effects. These compounds can reach the food chain by different ways and, therefore, the analysis of PAHs in food is a matter of concern. This article reviews the extraction methodologies together with the separation and detection techniques which are currently applied in the determination of PAHs in food and beverages. Specific extraction conditions, performance characteristics, chromatographic and detection parameters are discussed. A review of the occurrence of these compounds in the matrixes under study is also provided. PMID:20828703

Plaza-Bolaños, Patricia; Frenich, Antonia Garrido; Vidal, José Luis Martínez

2010-10-01

406

Hypothetical Two-Step Initiation of Experimental Carcinogenesis by Polycyclic Aromatic Hydrocarbons and Aminoazo Dyes  

PubMed Central

A new hypothesis is discussed, which describes the initiation of the carcinogenesis through polycyclic aromatic hydrocarbons (PAHs) and aminoazo dyes (AZOs) as a two-step process: the oncogenic proteins of the ras or ras-like on-cogenes activated by mutation (“initiation A ”) co-operate with the complexes in the plasma membrane formed during the "initiation B " stage from the parent compounds of the PAHs or AZOs with cholesterol and apolipoprotein A-I. The final result of this co-operation, or the "complete initiation", is an irreversibly modified membrane architecture with negative consequences for growth control. PMID:22582097

Contag, Bodo

2012-01-01

407

Polycyclic aromatic hydrocarbons in soils: Sources, behavior, and indication significance (a review)  

NASA Astrophysics Data System (ADS)

The current ideas of polycyclic aromatic hydrocarbons (PAHs) in soils are reviewed. Their natural and anthropogenic sources are discussed, and the mechanisms of their arrival from other environmental components to soils are considered. The main processes typical for PAHs in soils are defined; the sorption, degradation, and translocation features of polyarenes in the soil profile are shown. Attention is paid to the geographical features of the PAH distribution in soils. The use of data on the PAHs in soils for the indication of different natural and technogenic processes is also discussed.

Tsibart, A. S.; Gennadiev, A. N.

2013-07-01

408

Palladium-Catalyzed Oxidative Carbonylation for the Synthesis of Polycyclic Aromatic Hydrocarbons (PAHs).  

PubMed

A direct and facile palladium-catalyzed C-H bond oxidative carbonylation reaction and oxidative cyclization for the synthesis of polycyclic aromatic hydrocarbons (PAHs) is reported herein. The intramolecular cyclocarbonylation, through C-H activation and C-C, C-O bond formations under mild conditions, proceeds smoothly with good functional group tolerance in high to excellent yields. The intramolecular palladium-catalyzed direct oxidative C-H bond functionalization for the C-O bond formation is also demonstrated, which provides an efficient approach for the construction of various PAHs. PMID:25353393

Ji, Fanghua; Li, Xianwei; Wu, Wanqing; Jiang, Huanfeng

2014-11-21

409

The Pollution Surveys and Analysis of Polycyclic Aromatic Hydrocarbons at Mineral Separation Plant  

Microsoft Academic Search

range from 1.03 ng\\/m 3 to 23.35 ng\\/m 3 (PM10) and 0.24 ng\\/m 3 to 18.75 ng\\/m 3 ( PM2.5), with an overall mean of 5.07 ( PM10) and 3.91 ( PM2.5). Indicate the serious pollution of ploycyclic aromatic hydrocarbons in the mineral separation plant, be harmful to health of workers and should be attached importance by corrective department.

Guanghua Ai; Yanqiong Tu; Xiuxiang Tao; Yong Wang

2011-01-01

410

Concentration of polycyclic aromatic hydrocarbons (PAHs) in moss (Hypnum cupressiforme) from Hungary.  

PubMed

Mosses of the species Hypnum cupressiforme were collected from different parts of Hungary to investigate the air quality of the region. The concentrations of polycyclic aromatic hydrocarbons (PAHs) in species were determined. Low molecular weight PAHs (up to three ring compounds) contribute more than 99% to the concentrations of PAHs in Moss samples. The pattern of PAHs suggests local sources rather than long-range transport of contamination in the air. Possible local sources are industrial, urban, and traffic activities. The results indicate incomplete combustion of fuel is largely responsible for the air quality of the area. PMID:14533926

Kozák, Imre Olivér; Kozák, Melinda; Fekete, Jeno; Sharma, Virender K

2003-01-01

411

Interrelationship of Pyrogenic Polycyclic Aromatic Hydrocarbon (PAH) Contamination in Different Environmental Media.  

PubMed

Interrelationships between pyrogenic polycyclic aromatic hydrocarbons (PAHs) were assessed in air, soil, water, sediment, and tree leaves by using multi-media monitoring data. Concurrent concentration measurements were taken bimonthly for a year for the multi-media at urban and suburban sites. PAH level correlations between air and other media were observed at the urban site but were less clear at the suburban site. Considering a closer PAHs distribution/fate characteristics to soil than suspended solids, contamination in sediment seemed to be governed primarily by that in soil. The partitioning of PAHs in waters could be better accounted for by sorption onto black carbon and dissolved organic carbon. PMID:22303141

Kim, Seung-Kyu; Lee, Dong Soo; Shim, Won Joon; Yim, Un Hyuk; Shin, Yong-Seung

2009-01-01

412

Trends and factors governing polycyclic aromatic hydrocarbon levels in Tokyo Bay sediments  

NASA Astrophysics Data System (ADS)

Polycyclic aromatic hydrocarbons (PAHs) in a dated sediment core from Tokyo Bay were determined by gas chromatography and GC/MS. These PAHs increase in concentration from the 1950's to the beginning of the 1970's and decrease after then. These changes, especially the decreasing trend, are discussed with respect to changes in the atmospheric paniculate concentration and fossil fuel consumption in Tokyo and districts. The results suggest that the increase in PAH concentrations was due to the increase in the fossil fuel consumption, and the decreasing trend was caused by the following factors: 1) less fuel oil consumption; 2) legal curbs on industrial and vehicular emissions of particulates and hydrocarbons; and 3) other factors such as a gradual decrease in consumption of heavy oil and a temporary drop in the use of asphalt.

Ohta, Keiichi; Handa, Nobuhiko; Matsumoto, Eiji

1983-09-01

413

Environmental and microbiological factors affecting the biodegradation and detoxification of polycyclic aromatic hydrocarbons  

SciTech Connect

The microbial degradation of polycyclic aromatic hydrocarbons (PAHs) were investigated in microcosms containing sediment and water from freshwater and estuarine ecosystems. A ranking of six PAHs by mineralization rates are as follows: naphthalene (2.4-4.4) > phenanthrene (4-18) > 2-methylnaphthalene (14-20) > pyrene (34 ..-->.. 90) greater than or equal to 3-methylcholanthrene (87 ..-->.. 200) greater than or equal to benzo(a)pyrene (200 ..-->.. 300). PAH residues persisted two- to four-times longer in a pristine ecosystem and mineralization of higher molecular weight PAHs (greater than or equal to four rings) totaled 0.2-6.5% after eight weeks. Relative differences in PAH mineralization were related to levels of PAH residues and elevated populations of hydrocarbon-degrading microorganisms. GC/MS analyses of organic extractable residues from microcosms exposed to naphthalene indicated that cis-1,2-naphthalene- dihydrodiol, 1-naphthol, salicyclic acid and catechol were metabolites of naphthalene.

Heitkamp, M.A.

1987-01-01

414

Degradation of polycyclic aromatic hydrocarbons in the presence of synthetic surfactants  

SciTech Connect

The biodegradation of polycyclic aromatic hydrocarbons (PAH) often is limited by low water solubility and dissolution rate. Nonionic surfactants and sodium dodecyl sulfate increased the concentration of PAH in the water phase because of solubilization. The degradation of PAH was inhibited by sodium dodecyl sulfate because this surfactant was preferred as a growth substrate. Growth of mixed cultures with phenanthrene and fluroanthrene solubilized by a nonionic surfactant prior to inoculation was exponential, indicating a high bioavailability of the solubilized hydrocarbons. Nonionic surfactants of the alkylethoxylate type and the alkylphenolethoxylate type with an average ethoxylate chain length of 9 to 12 monomers were toxic to a PAH-degrading Mycobacterium sp. and to several PAH-degrading mixed cultures. Toxicity of the surfactants decreased with increasing hydrophilicity, i.e., with increasing ethoxylate chain length. Nontoxic surfactants enhanced the degradation of fluorene, phenanthrene, anthracene, fluoranthene, and pyrene.

Tiehm, A. (Universitaet Karlsruhe (Germany))

1994-01-01

415

Porticoccus hydrocarbonoclasticus sp. nov., an aromatic hydrocarbon-degrading bacterium identified in laboratory cultures of marine phytoplankton.  

PubMed

A marine bacterium, designated strain MCTG13d, was isolated from a laboratory culture of the dinoflagellate Lingulodinium polyedrum CCAP1121/2 by enrichment with polycyclic aromatic hydrocarbons (PAHs) as the sole carbon source. Based on 16S rRNA gene sequence comparisons, the strain was most closely related to Porticoccus litoralis IMCC2115(T) (96.5%) and to members of the genera Microbulbifer (91.4 to 93.7%) and Marinimicrobium (90.4 to 92.0%). Phylogenetic trees showed that the strain clustered in a distinct phyletic line in the class Gammaproteobacteria for which P. litoralis is presently the sole cultured representative. The strain was strictly aerobic, rod shaped, Gram negative, and halophilic. Notably, it was able to utilize hydrocarbons as sole sources of carbon and energy, whereas sugars did not serve as growth substrates. The predominant isoprenoid quinone of strain MCTG13d was Q-8, and the dominant fatty acids were C(16:1?7c), C(18:1?7c), and C(16:0). DNA G+C content for the isolate was 54.9 ± 0.42 mol%. Quantitative PCR primers targeting the 16S rRNA gene of this strain showed that this organism was common in other laboratory cultures of marine phytoplankton. On the basis of phenotypic and genotypic characteristics, strain MCTG13d represents a novel species of Porticoccus, for which the name Porticoccus hydrocarbonoclasticus sp. nov. is proposed. The discovery of this highly specialized hydrocarbon-degrading bacterium living in association with marine phytoplankton suggests that phytoplankton represent a previously unrecognized biotope of novel bacterial taxa that degrade hydrocarbons in the ocean. PMID:22139001

Gutierrez, Tony; Nichols, Peter D; Whitman, William B; Aitken, Michael D

2012-02-01

416

Distribution of trace metals, aliphatic hydrocarbons and polycyclic aromatic hydrocarbons in sediment cores from the Sicily Channel and the Gulf of Tunis (south?western Mediterranean Sea)  

Microsoft Academic Search

Under the framework of the IAEA's Technical Co?operation project RAF7\\/004, international research cruises were carried out in 2004 to assess the distribution of radionuclides and micropollutants in the south?western Mediterranean Sea. Sediments samples had variable concentrations of total aliphatic hydrocarbons and polycyclic aromatic hydrocarbons ranging from 0.2 to 1.8 µg g and 26.9 to 364.4 ng g, respectively, in the

Nadia Mzoughi; Lassaad Chouba

2011-01-01

417

Aliphatic and polycyclic aromatic hydrocarbons in sediments of the Slovenian coastal area (Gulf of Trieste, northern Adriatic).  

PubMed

The distribution and sources of aliphatic and polycyclic aromatic hydrocarbons (PAH) were determined in sediments at seven sites around the Slovenian coastal area. The potential toxicological significance was also assessed using biological thresholds. The results of the analyses showed higher concentrations of hydrocarbons in the Port of Koper and in the Marina of Portoroz. The influence of pollution was also evident in rather higher concentrations of hydrocarbons in the surrounding area in the Bays of Koper and Piran. Concentrations of hydrocarbons decrease toward the central part of the Gulf of Trieste. The major component of the aliphatic fraction was the unresolved complex mixture. Concentrations of the total resolved aliphatic hydrocarbons were in a range from 689 to 3,164 ng g(-1). Concentrations of the total PAHs were between 330 and 1,173 ng g(-1). Polycyclic aromatic hydrocarbons are primarily of pyrolytic origin with some smaller contributions of the petrogenic, while the aliphatic are mostly of petrogenic origin with significant amounts of biogenic derived compounds of terrestrial and marine origin. Strong evidence of the diagenetic origin of perylene in the investigated area was also found. Quite a good linear relationship between PAH concentration and TOC and between aliphatic hydrocarbon concentrations and TOC was observed. The principal component analysis showed differences between the nearshore and offshore sites. In general, the investigated area is moderately contaminated by hydrocarbons. Concentrations of PAHs, hydrocarbons of high concern, are below the levels (effects range low and the effects range median) associated with adverse biological effects. PMID:22270593

Bajt, Oliver

2012-12-01

418

Sample preparation procedure for the determination of polycyclic aromatic hydrocarbons in petroleum vacuum residue and bitumen.  

PubMed

This paper describes a novel method of sample preparation for the determination of trace concentrations of polycyclic aromatic hydrocarbons (PAHs) in high-boiling petroleum products. Limits of quantitation of the investigated PAHs in materials of this type range from tens of nanograms per kilogram to <20 ?g/kg. The studies revealed that in order to separate most of interferences from the analytes without a significant loss of PAHs, it is necessary to use size exclusion chromatography as the first step of sample preparation, followed by adsorption using normal-phase liquid chromatography. The use of orthogonal separation procedure described in the paper allows the isolation of only a group of unsubstituted and substituted aromatic hydrocarbons with a specific range of molar mass. The lower the required limit of quantitation of PAHs, the larger is the scale of preparative liquid chromatography in both steps of sample preparation needed. The use of internal standard allows quantitative results to be corrected for the degree of recovery of PAHs during the sample preparation step. Final determination can be carried out using HPLC-FLD, GC-MS, or HPLC-UV-VIS/DAD. The last technique provides a degree of identification through the acquired UV-VIS spectra. PMID:21647802

Gilgenast, Ewelina; Boczkaj, Grzegorz; Przyjazny, Andrzej; Kami?ski, Marian

2011-08-01

419

Biodegradation of polycyclic aromatic hydrocarbons by Sphingomonas strains isolated from the terrestrial subsurface  

SciTech Connect

Several strains of Sphingomonas isolated from deep Atlantic coastal plain aquifers at the US Department of Energy Savannah River Site (SRS) near Aiken, SC were shown to degrade a variety of aromatic hydrocarbons in a liquid culture medium. Sphingomonas aromaticivorans strain B0695 was the most versatile of the five strains examined. This strain was able to degrade acenaphthene, anthracene, phenanthrene, 2,3-benzofluorene, 2-methyl naphthalene, 2,3-dimethylnaphthalene, and fluoranthene in the presence of 400 mg l(-1) Tween 80. Studies involving microcosms composed of aquifer sediments showed that S. aromaticivorans B0695 could degrade phenanthrene effectively in sterile sediment and could enhance the rate at which this compound was degraded in nonsterile sediment. These findings indicate that it may be feasible to carry out (or, at least, to enhance) in situ bioremediation of phenanthrene-contaminated soils and subsurface environments with S. aromaticivorans B0695. In contrast, stra in B0695 was unable to degrade fluoranthene in microcosms containing aquifer sediments, even though it readily degraded this polynuclear aromatic hydrocarbon (PAH) in a defined liquid growth medium.

Shi, T; Fredrickson, Jim K.; Balkwill, David L.

2001-05-01

420

Biomarker sensitivity for polynuclear and halogenated aromatic hydrocarbon contamination in fish species from Galveston Bay  

SciTech Connect

The Galveston Bay estuary exhibits a contamination gradient for polynuclear aromatic hydrocarbons (PAHs) and halogenated aromatic hydrocarbons, which is useful for comparing biomarker response sensitivity in fish taken from different bay locations. Two fish species, hardhead catfish (Arius felis) and Atlantic croaker (Micropogon undulatus), were collected from four stations where sediment total PAHs ranged from 68 to > 1,000 ng/g. Hardhead catfish showed no consistent CYP1A mediated responses (hepatic ethoxyresorufin-O-deethylase activity (EROD), CYP1A mRNA levels, or CYP1A immunoreactive protein) in the field collected fish or in fish dosed with up to 15 mg/kg benzo(a)pyrene (BaP). Significant differences were seen in field collected hardhead catfish in biliary concentrations of naphthalene, phenanthrene, and BaP metabolites. Conversely, in croakers taken from the same four Galveston Bay locations, there were significant elevations IN EROD and glutathione-S-transferase activities, CYP1A immunoreactive protein, and biliary PAH metabolites at the contaminated stations. These studies suggest that croaker is a good monitoring species especially with respect to induction of CYP1A mediated responses by PAHs. Biliary PAH metabolites and PAH-DNA adducts were sensitive to PAH contamination in both species.

Willett, K.; McDonald, S.; Steinberg, M.; Beatty, K.; Safe, S. [Texas A and M Univ., College Station, TX (United States)

1995-12-31

421

Semivolatile and particulate polycyclic aromatic hydrocarbons in environmental tobacco smoke. Cleanup, speciation, and emission factors  

SciTech Connect

Studies of phase distributions and emission factors for polycyclic aromatic hydrocarbons (PAH) in environmental tobacco smoke (ETS) require collection and analysis of very small samples. To achieve the necessary selectivity and sensitivity, a method has been devised and tested for extraction and cleanup of gas- and particulate-phase ETS samples. Gas-phase species were trapped by polymeric sorbents, and particles were trapped on filters. The samples were extracted with hot cyclohexane, concentrated, and passed through silica solid-phase extraction columns for cleanup. After solvent change, the PAH were determined by high-performance liquid chromatography with two programmed fluorescence detectors. PAH concentrations in 15-mg aliquots of National Institute of Standards and Technology Standard Reference Material (SRM) 1649 (urban dust/organics) agreed well with published values. Relative precision at the 95% confidence level was 8% for SRM 1649 and 20% for replicate samples (5-mg) of ETS particles. Emission factors have been measured for a range of gas- and particulate-phase polycyclic aromatic hydrocarbons in ETS. The emission factors per cigarette were 13.0 {+-} 0.5 mg of particulate matter, 11.2 + 0.9 {mu}g for gas-phase napthalene, and 74 {+-} 10 ng for particulate benzo[a]pyrene. 21 refs., 5 figs., 7 tabs.

Gundel, L.A.; Mahanama, K.R.R.; Daisey, J.M. [Lawrence Berkeley Lab., CA (United States)]|[Univ. of California, Berkeley, CA (United States)

1995-06-01

422

Aromatic hydrocarbons, diamonds, and fullerenes in interstellar space: puzzles to be solved by laboratory and theoretical astrochemistry.  

PubMed

New research is presented, and previous research is reviewed, on the emission and absorption of interstellar aromatic hydrocarbons. Emission from aromatic hydrocarbons dominates the mid-infrared emission of many galaxies, including our own Milky Way galaxy. Only recently have aromatic hydrocarbons been observed in absorption in the interstellar medium, along lines of sight with high column densities of interstellar gas and dust. Much work on interstellar aromatics has been carried out, with astronomical observations and laboratory and theoretical astrochemistry. In many cases, the predictions of laboratory and theoretical work are confirmed by astronomical observations but, in other cases, clear discrepancies exist that provide problems to be solved by a combination of astronomical observations, laboratory studies, and theoretical studies. The emphasis of this paper will be on current outstanding puzzles concerning aromatic hydrocarbons that require further laboratory and theoretical astrochemistry to resolve. This paper will also touch on related topics where laboratory and theoretical astrochemistry studies are needed to explain astrophysical observations, such as a possible absorption feature due to interstellar 'diamonds' and the search for fullerenes in space. PMID:11345243

Sellgren, K

2001-03-15

423

Aromatic Hydrocarbons, Diamonds, and Fullerenes in Interstellar Space: Puzzles to be Solved by Laboratory and Theoretical Astrochemistry  

E-print Network

New research is presented, and previous research is reviewed, on the emission and absorption of interstellar aromatic hydrocarbons. Emission from aromatic hydrocarbons dominate the mid-infrared emission of many galaxies, including our own Milky Way galaxy. Only recently have aromatic hydrocarbons been observed in absorption in the interstellar medium, along lines of sight with high column densities of interstellar gas and dust. Much work on interstellar aromatics has been done, with astronomical observations and laboratory and theoretical astrochemistry. In many cases the predictions of laboratory and theoretical work are confirmed by astronomical observations, but in other cases clear discrepancies exist which provide problems to be solved by a combination of astronomical observations, laboratory studies, and theoretical studies. The emphasis of this paper will be on current outstanding puzzles concerning aromatic hydrocarbons which require further laboratory and theoretical astrochemistry to resolve. This paper will also touch on related topics where laboratory and theoretical astrochemistry studies are needed to explain astrophysical observations, such as a possible absorption feature due to interstellar "diamonds" and the search for fullerenes in space.

K. Sellgren

2000-10-06

424

Polycyclic aromatic hydrocarbons inhibit the activity of acetylcholinesterase purified from electric eel.  

PubMed

Polycyclic aromatic hydrocarbons (PAHs) are formed during the incomplete combustion of fossil fuels, wood and municipal waste incineration, from internal combustion engines, and from various food cooking operations and are common environmental contaminants which have been detected in surface waters, sediments, soils, plants, and both rural and urban air. In this study, we have shown that, for the first time, in vitro addition of PAHs dose-dependently inhibited the activity of acetylcholinesterase purified from electric eel in a competitive manner. The PAHs containing 3 or higher aromatic rings showed the highest inhibitory effect with the IC50 values between 2 and 6 ppm. Among the PAHs tested, chrysene and pyrene exhibit the highest and lowest potency with IC50 values of 2. 40+/-0.04 and 5.22+/-0.38 ppm, respectively. PAHs with lower number of aromatic rings, such as naphthalene, acenaphthylene and fluorene, and oxygenated PAHs, such as anthraquinone and xanthone, showed no or slight inhibition of the acetylcholinesterase activity. PMID:9299514

Kang, J J; Fang, H W

1997-09-18

425

Determination of C6-C10 aromatic hydrocarbons in water by purge-and-trap capillary gas chromatography  

USGS Publications Warehouse

A method is described for the determination of the C6-C10 aromatic hydrocarbons in water based on purge-and-trap capillary gas chromatography with flame ionization and mass spectrometric detection. Retention time data and 70 eV mass spectra were obtained for benzene and all 35 C7-C10 aromatic hydrocarbons. With optimized chromatographic conditions and mass spectrometric detection, benzene and 33 of the 35 alkylbenzenes can be identified and measured in a 45-min run. Use of a flame ionization detector permits the simultaneous determination of benzene and 26 alkylbenzenes.

Eganhouse, R. P.; Dorsey, T. F.; Phinney, C. S.; Westcott, A. M.

1993-01-01

426

Analysis of the impregnation of ZnO:Mn2+ nanoparticles on cigarette filters for trapping polycyclic aromatic hydrocarbons (PAHs)  

NASA Astrophysics Data System (ADS)

Each cigarette can generate 1149 ng of a mixture of 14 polycyclic aromatic hydrocarbons, of which there are a lot of information about its harmful effects on the environment and human health, they are considered mutagenic, teratogenic and carcinogenic. In this paper we tested ZnO:Mn2+ nanoparticles, attached to the filters of cigarettes. The first results showed that the filtration system was able to catch the Benzo(a)pyrene contained in cigarette smoke; but more tests are needed to quantify the efficiency with greater accuracy over other polycyclic aromatic hydrocarbons.

Estrada-Izquierdo, Irma; Sánchez-Espindola, Esther; Uribe-Hernández, Raúl; Ramón-Gallegos, Eva

2012-10-01

427

Emissions of polycyclic aromatic hydrocarbons from batch hot mix asphalt plants.  

PubMed

This study was set out to assess the characteristics of polycyclic aromatic hydrocarbon (PAH) emissions from batch hot mix asphalt (HMA) plants and PAH removal efficiencies associated with their installed air pollution control devices. Field samplings were conducted on six randomly selected batch HMA plants. For each selected plant, stack flue gas samples were collected from both stacks of the batch mixer (n = 5) and the preheating boiler (n = 5), respectively. PAH samples were also collected from the field to assess PAHs that were directly emitted from the discharging chute (n = 3). To assess PAH removal efficiencies of the installed air pollution control devices, PAH contents in both cyclone fly ash (n=3) and bag filter fly ash (n = 3) were analyzed. Results show that the total PAH concentration (mean; RSD) in the stack flue gas of the batch mixer (354 microg/Nm3; 78.5%) was higher than that emitted from the discharging chute (107 microg/Nm3; 70.1%) and that in the stack flue gas of the preheating boiler (83.7 microg/Nm3; 77.6%). But the total BaPeq concentration of that emitted from the discharging chute (0.950 microg/Nm3; 84.4%) was higher than contained in the stack flue gas of the batch mixer (0.629 microg/Nm3; 86.8%) and the stack flue gas of the preheating boiler (= 0.112 microg/Nm3; 80.3%). The mean total PAH emission factor for all selected batch mix plants (= 139 mg/ton x product) was much higher than that reported by U.S. EPA for the drum mix asphalt plant (range = 11.8-79.0 mg/ton x product). We found the overall removal efficiency of the installed air pollution control devices (i.e., cyclone + bag filter) on total PAHs and total BaPeq were 22.1% and 93.7%, respectively. This implies that the installed air pollution control devices, although they have a very limited effect on the removal of total PAHs, do significantly reduce the carcinogenic potencies associated with PAH emissions from batch HMA plants. PMID:15543726

Lee, Wen-Jhy; Chao, Wen-Hui; Shih, Minliang; Tsai, Cheng-Hsien; Chen, Thomas Jeng-Ho; Tsai, Perng-Jy

2004-10-15

428

The influence of baking fuel on residues of polycyclic aromatic hydrocarbons and heavy metals in bread.  

PubMed

The influence of fuel type used to bake bread on the spectrum and concentrations of some polycyclic aromatic hydrocarbons and heavy metals in baked bread was assessed. Bread samples were collected from different bakeries operated by either electricity, solar, mazot or solid waste and their residue content of PAHs and heavy metals was assessed. The total concentration of PAHs detected in mazot, solar, solid waste and electricity operated bakeries had an average of 320.6, 158.4, 317.3 and 25.5 microgkg(-1), respectively. Samples collected from mazot, solar and solid waste operated bakeries have had a wide spectrum of PAHs, in comparison to that detected in bread samples collected from electricity operated bakeries. Lead had the highest concentrations in the four groups of bread samples, followed by nickel, while the concentrations of zinc and cadmium were the least. The concentration of lead detected in bread samples produced from mazot, solar, solid waste and electricity fueled bakeries were 1375.5, 1114, 1234, and 257.3 microgkg(-1), respectively. Estimated daily intake of PAHs based on bread consumption were 48.2, 28.5, 80. 1, and 4.8 microg per person per day for bread produced in bakeries using mazot, solar, solid waste and electricity, respectively. Meanwhile, the estimated daily intake of benzo (a) pyrene were 3.69, 2.65, 8.1, and 0.81 microg per person per day for bread sample baked with mazot, solar, solid waste and electricity, respectively. The daily intake of lead, based on bread consumption was 291, 200.5, 222, and 46.31 microg per person per day for bread sample baked with mazot, solar, solid waste and electricity, respectively. The present work has indicated the comparatively high level of daily intake of benzo (a) pyrene and lead in comparison to levels reported from many other countries and those recommended by international regulatory bodies. It is probable that residues detected in bread samples are partially cereal-borne but there is strong evidence that the process of baking and the gases emitted are responsible for most of the contamination load. PMID:11080564

Ahmed, M T; Abdel Hadi el-S; el-Samahy, S; Youssof, K

2000-12-30

429

Aliphatic and polycyclic aromatic hydrocarbons in Gulf of Trieste sediments (northern Adriatic): potential impacts of maritime traffic.  

PubMed

The Gulf of Trieste (northern Adriatic) is one of the most urbanized and industrialized areas in the northern Adriatic, with intense maritime traffic experienced at multiple ports. The impact of maritime traffic on contamination by hydrocarbons in this area was assessed. Concentrations of hydrocarbons were higher near the expected contamination sources and still elevated in the adjacent offshore areas. Aliphatic hydrocarbons were mainly of petrogenic origin, with some contribution of biogenic origin. A continuous contamination by aliphatic hydrocarbons and degradation processes were hypothesized. Concentrations of total polycyclic aromatic hydrocarbons (PAH) were generally greater near the contamination sources. Compared to the prevailing pyrolytic origin, the petrogenic PAH origin seemed to be less important, but not negligible. Results revealed that intensive maritime traffic is a probable source of contamination by hydrocarbons in the investigated area, which is largely limited to areas near the contamination sources. PMID:24997612

Bajt, Oliver

2014-09-01

430

Abundances of polycyclic aromatic hydrocarbons (PAHs) in 14 chinese and american coals and their relation to coal rank and weathering  

USGS Publications Warehouse

The abundances of 16 polycyclic aromatic hydrocarbons (PAHs) on the priority list of the United States Environmental Protection Agency (U.S. EPA) have been determined in 14 Chinese and American coals. The ranks of the samples range from lignite, bituminous coal, anthracite, to natural coke. Soxhlet extraction was conducted on each coal for 48 h. The extract was analyzed on a gas chromatograph-mass spectrometer (GC-MS). The results show that the total PAH content ranged from 0.31 to 57.6 ??g/g of coal (on a dry basis). It varied with coal rank and is highest in the maturity range of bituminous coal rank. High-molecular-weight (HMW) PAHs are predominant in low-rank coals, but low-molecular-weight (LMW) PAHs are predominant in high-rank coals. The low-sulfur coals have a higher PAH content than high-sulfur coals. It may be explained by an increasing connection between disulfide bonds and PAHs in high-sulfur coal. In addition, it leads us to conclude that the PAH content of coals may be related to the depositional environment. ?? 2010 American Chemical Society.

Wang, R.; Liu, G.; Zhang, J.; Chou, C.-L.; Liu, J.

2010-01-01

431

Near-critical and supercritical fluid extraction of polycyclic aromatic hydrocarbons from town gas soil  

SciTech Connect

The contamination of soil by hazardous and toxic organic pollutants is an ever-growing problem facing the global community. One particular family of contaminants that are of major importance are polycyclic aromatic hydrocarbons (PAHs). PAHs are the result of coal gasification and high-temperature processes. Sludges from these town gas operations were generally disposed of into unlined pits and left there for eventual biodegradation. However, the high levels of PAH contained in the pits prevented the occurrence of biodegradation. PAH contaminated soil is now considered hazardous and must be cleaned to environmentally acceptable standards. One method for the remediation is extraction with supercritical water. Water in or about its critical region exhibits enhanced solvating power toward most organic compounds. Contaminated soil containing 4% by mass of hydrocarbons was ultra-cleaned in a 300-cm{sup 3} semicontinuous system to an environmentally acceptable standard of less than 200 ppm residual hydrocarbon concentration. The effects of subcritical or supercritical extraction, solvent temperature, pressure, and density have been studied, and the discerning characteristics of this type of fluid have been identified. The efficiencies of subcritical and supercritical extraction have been discussed from a process engineering standpoint.

Kocher, B.S.; Azzam, F.O.; Cutright, T.J.; Lee, S. [Univ. of Akron, OH (United States). Dept. of Chemical Engineering

1995-03-01

432

Molecular Tracers of Saturated and Polycyclic Aromatic Hydrocarbon Inputs into Central Park Lake, New York City  

PubMed Central

Saturated hydrocarbons (SH) and polycyclic aromatic hydrocarbons (PAHs) have been quantified in a sediment core obtained from Central Park Lake, New York City. Radionuclides 210Pb and 137Cs were used to assign approximate dates to each individual section in the core. The dating profile based on 210Pb matches very well with the time constraints provided by 137Cs. Radionuclide-derived depositional dates are consistent with temporal information from the petroleum-indicator ratio U/R [the ratio of unresolved complex mixture (UCM) to saturated hydrocarbons in the aliphatic fraction] and the history of fuel use in the NYC area. Ratios of 1,7-dimethylphenanthrane (DMP) to 1,7-DMP plus 2,6-DMP [1,7/(1,7 + 2,6)-DMP], retene to retene plus chrysene [Ret/(Ret + Chy)], and fluoranthene to fluoranthene plus pyrene [Fl/(Fl + Py)] provide additional source discrimination throughout the core. Results show that the ratio U/R is sensitive to petroleum inputs and Ret/(Ret + Chy) is responsive to contributions from softwood combustion, whereas both Fl/(Fl + Py) and 1,7/(1,7 + 2,6)-DMP can be used to discriminate among wood, coal, and petroleum combustion sources. Combined use of these ratios suggests that in New York City, wood combustion dominated 100 years ago, with a shift to coal combustion occurring from the 1900s to the 1950s. Petroleum use began around the 1920s and has dominated since the 1940s. PMID:16201624

YAN, BEIZHAN; ABRAJANO, TEOFILO A.; BOPP, RICHARD F.; CHAKY, DAMON A.; BENEDICT, LUCILLE A.; CHILLRUD, STEVEN N.

2011-01-01

433

Atmospheric photochemistry of aromatic hydrocarbons: OH budgets during SAPHIR chamber experiments  

NASA Astrophysics Data System (ADS)

Current photochemical models developed to simulate the atmospheric degradation of aromatic hydrocarbons tend to underestimate OH radical concentrations. In order to analyse OH budgets, we performed experiments with benzene, toluene, p-xylene, and 1,3,5-trimethylbenzene in the atmosphere simulation chamber SAPHIR. Experiments were conducted under low-NO conditions (typically 0.1-0.2 ppb) and high-NO conditions (typically 7-8 ppb), and starting concentrations of 6-250 ppb of aromatics, dependent on OH rate constants. For the OH budget analysis a steady-state approach was applied where OH production and destruction rates (POH and DOH) have to be equal. The POH were determined from measurements of HO2, NO, HONO, and O3 concentrations, considering OH formation by photolysis and recycling from HO2. The DOH were calculated from measurements of the OH concentrations and total OH reactivities. The OH budgets were determined from DOH / POH ratios. The accuracy and reproducibility of the approach were assessed in several experiments using CO as a reference compound where an average ratio DOH / POH = 1.13 ± 0.19 was obtained. In experiments with aromatics, these ratios ranged within 1.1-1.6 under low-NO conditions and 0.9-1.2 under high-NO conditions. The results indicate that OH budgets during photo-oxidation experiments with aromatics are balanced within experimental accuracies. Inclusion of a further, recently proposed OH production via HO2 + RO2 reactions led to improvements under low-NO conditions but the differences were small and insignificant within the experimental errors.

Nehr, S.; Bohn, B.; Dorn, H.-P.; Fuchs, H.; Häseler, R.; Hofzumahaus, A.; Li, X.; Rohrer, F.; Tillmann, R.; Wahner, A.

2014-03-01

434

Atmospheric photochemistry of aromatic hydrocarbons: OH budgets during SAPHIR chamber experiments  

NASA Astrophysics Data System (ADS)

Current photochemical models developed to simulate the atmospheric degradation of aromatic hydrocarbons tend to underestimate OH radical concentrations. In order to analyse OH budgets, we performed experiments with benzene, toluene, p-xylene and 1,3,5-trimethylbenzene in the atmosphere simulation chamber SAPHIR. Experiments were conducted under low-NO conditions (typically 0.1-0.2 ppb) and high-NO conditions (typically 7-8 ppb), and starting concentrations of 6-250 ppb of aromatics, dependent on OH rate constants. For the OH budget analysis a steady-state approach was applied in which OH production and destruction rates (POH and DOH) have to be equal. The POH were determined from measurements of HO2, NO, HONO, and O3 concentrations, considering OH formation by photolysis and recycling from HO2. The DOH were calculated from measurements of the OH concentrations and total OH reactivities. The OH budgets were determined from DOH/POH ratios. The accuracy and reproducibility of the approach were assessed in several experiments using CO as a reference compound where an average ratio DOH/POH = 1.13 ± 0.19 was obtained. In experiments with aromatics, these ratios ranged within 1.1-1.6 under low-NO conditions and 0.9-1.2 under high-NO conditions. The results indicate that OH budgets during photo-oxidation experiments with aromatics are balanced within experimental accuracies. Inclusion of a further, recently proposed OH production via HO2 + RO2 reactions led to improvements under low-NO conditions but the differences were small and insignificant within the experimental errors.

Nehr, S.; Bohn, B.; Dorn, H.-P.; Fuchs, H.; Häseler, R.; Hofzumahaus, A.; Li, X.; Rohrer, F.; Tillmann, R.; Wahner, A.

2014-07-01

435

Aliphatic and polycyclic aromatic hydrocarbons characterisation of Coimbra and Oporto PM2.5 urban aerosol  

NASA Astrophysics Data System (ADS)

The concentration of organic pollutants in urban areas is mostly due to incomplete combustion from vehicles, industries and domestic heating. Some of these compounds, principally the aliphatic (ALIPH) and polycyclic aromatic hydrocarbons (PAHs) promote harmful effects in human health. The determination of the ALIPH and PAHs concentration levels and their possible emission sources are useful for air quality management and source apportionment studies. In order to estimate and compare the ambient concentrations and establish the main sources of these compounds, the fine fraction of the atmospheric particulate matter (PM2.5) was collected simultaneously in Oporto and Coimbra during summer and winter seasons using a high volume sampler. The organic compounds were extracted from the particulate matter, under reflux with dichloromethane and the total organic extract (TOE) was fractionated by flash chromatography using five different eluents with increasing polarity. The hydrocarbon fractions were analysed by gas chromatography/mass spectrometry (GC/MS). Here we present and discuss the qualitative and quantitative composition of the aliphatic and aromatic fractions present in PM2.5 samples from both cities. The homologous series of C14 to C34 n-alkanes, isoprenoid hydrocarbons (pristane and phytane), PAHs and some petroleum markers have been identified and quantified. With the purpose of identifying the possible sources, various molecular diagnostic ratios were calculated. The global carbon preference index (CPI) closer to the unity, the large concentration of the unresolved complex mixture (UCM) and the presence of PAHs indicate that motor vehicle exhaust was the main emission source of the aliphatic and polycyclic aromatic fractions of Oporto and Coimbra aerosol, especially in the first city. Also, the remarkable presence of petroleum biomarkers such, as hopanes, confirms the previous results. Concentration ratios between PAHs were calculated and used to assign emission sources. The abundance and the sources of these organic pollutants for the two cities are discussed and compared taking into account the local/regional characteristics. Acknowledgement: The authors would like to thank Fundação para a Ciência e Tecnologia (FCT) for the financial support through the project POCI/AMB/60267/2004 which provided funding for the work presented here.

Rocha, A. C.; Mirante, F.; Gonçalves, C.; Nunes, T.; Alves, C.; Evtyugina, M.; Kowacz, M.; Pio, C.; Rocha, C.; Vasconcelos, T.

2009-04-01

436

Microbial in situ degradation of aromatic hydrocarbons in a contaminated aquifer monitored by carbon isotope fractionation  

NASA Astrophysics Data System (ADS)

We present an approach for characterizing in situ microbial degradation using the 13C/ 12C isotope fractionation of contaminants as an indicator of biodegradation. The 13C/ 12C isotope fractionation of aromatic hydrocarbons was studied in anoxic laboratory soil percolation columns with toluene or o-xylene as the sole carbon and electron source, and sulfate as electron acceptor. After approximately 2 months' of incubation, the soil microbial community degraded 32 mg toluene l -1 and 44 mg o-xylene l -1 to less than 0.05 mg l -1, generating a stable concentration gradient in the column. The 13C/ 12C isotope ratio in the residual non-degraded fraction of toluene and o-xylene increased significantly, corresponding to isotope fractionation factors (?C) of 1.0015 and 1.0011, respectively. When the extent of biodegradation in the soil column was calculated based on the measured isotope ratios ( Rt) and an isotope fractionation factor (?C=1.0017) obtained from a sulfate-reducing batch culture the theoretical residual substrate concentrations ( Ct) matched the measured toluene concentrations in the column. This indicated that a calculation of biodegradation based on isotope fractionation could work in systems like soil columns. In a field study, a polluted, anoxic aquifer was analyzed for BTEX and PAH contaminants. These compounds were found to exhibit a significant concentration gradient along an 800-m groundwater flow path downstream of the source of contamination. A distinct increase in the carbon isotope ratio ( ?13C) was observed for the residual non-degraded toluene (7.2‰), o-xylene (8.1‰) and naphthalene fractions (1.2‰). Based on the isotope values and the laboratory-derived isotope fractionation factors for toluene and o-xylene, the extent to which the residual substrate fraction in the monitoring wells had been degraded by microorganisms was calculated. The results revealed significant biodegradation along the groundwater flow path. In the wells at the end of the plume, the bioavailable toluene and o-xylene fractions had been almost completely reduced by in situ microbial degradation. Although indane and indene showed decreasing concentrations downstream of the groundwater flow path, suggesting microbial degradation, their carbon isotope ratios remained constant. As the physical properties of these compounds are similar to those of BTEX compounds, the constant isotope values of indane and indene indicated that microbial degradation did not lead to isotope fractionation of all aromatic hydrocarbons. In addition, physical interaction with the aquifer material during the groundwater passage did not significantly alter the carbon isotope composition of aromatic hydrocarbons.

Richnow, Hans H.; Annweiler, Eva; Michaelis, Walter; Meckenstock, Rainer U.

2003-08-01

437

Study of the interaction between water and hydrogen sulfide with polycyclic aromatic hydrocarbons  

NASA Astrophysics Data System (ADS)

A computational study has been carried out for determining the characteristics of the interaction between one water and hydrogen sulfide molecule with a series of polycyclic aromatic hydrocarbons of increasing size, namely, benzene, anthracene, triphenylene, coronene, circumcoronene, and dicircumcoronene. Potential energy curves were calculated for structures where H2X (X=O,S) molecule is located over the central six-membered ring with its hydrogen atoms pointing toward to (mode A) or away from (mode B) the hydrocarbon. The accuracy of different methods has been tested against the results of coupled cluster calculations extrapolated to basis set limit for the smaller hydrocarbons. The spin component scaled MP2 (SCS-MP2) method and a density functional theory method empirically corrected for dispersion (DFT-D) reproduce fairly well the results of high level calculations and therefore were employed for studying the larger systems, though DFT-D seems to underestimate the interaction in hydrogen sulfide clusters. Water complexes in mode A have interaction energies that hardly change with the size of the hydrocarbon due to compensation between the increase in the correlation contribution to the interaction energy and the increase in the repulsive character of the Hartree-Fock energy. For all the other clusters studied, there is a continuous increase in the intensity of the interaction as the size of the hydrocarbon increases, suggesting already converged values for circumcoronene. The interaction energy for water clusters extrapolated to an infinite number of carbon atoms amounts to -13.0 and -15.8 kJ/mol with SCS-MP2 and DFT-D, respectively. Hydrogen sulfide interacts more strongly than water with the hydrocarbons studied, leading to a limiting value of -21.7 kJ/mol with the SCS-MP2 method. Also, complexes in mode B are less stable than the corresponding A structures, with interaction energies amounting to -8.2 and -18.2 kJ/mol for water and hydrogen sulfide, respectively. The DFT-D calculations give values of -16.2 and -9.3 kJ/mol for hydrogen sulfide complexes in modes A and B, less negative than those predicted by the SCS-MP2 method, probably indicating problems with sulfur dispersion parameters.

Cabaleiro-Lago, Enrique M.; Carrazana-García, Jorge A.; Rodríguez-Otero, Jesús

2009-06-01

438

Sedimentary record of polycyclic aromatic hydrocarbons in a sediment core from the Pearl River Estuary, South China  

Microsoft Academic Search

Owing to the hydrodynamic and sedimentation conditions, the western shoal of the Pearl River Estuary (PRE) is known to be an important sink of terrestrial substances including particle-associated pollutants from the Pearl River Delta (PRD) region. In this study, we report the sedimentary record of polycyclic aromatic hydrocarbons (PAHs) during the 20th century in a sediment core from the western

G. Q. Liu; G. Zhang; X. D. Li; J. Lia; X. Z. Peng; S. H. Qi

2005-01-01

439

The ‘soot line’: Destruction of presolar polycyclic aromatic hydrocarbons in the terrestrial planet-forming region of disks  

Microsoft Academic Search

Interstellar material is highly processed when subjected to the physical conditions that prevail in the inner regions of protoplanetary disks, the potential birthplace of habitable planets. Polycyclic aromatic hydrocarbons (PAHs) are abundant in the interstellar medium, and they have also been observed in the disks around young stars, with evidence for some modification in the latter. Using a chemical model

Monika E. Kress; Alexander G. G. M. Tielens; Michael Frenklach

2010-01-01

440

The `soot line': Destruction of presolar polycyclic aromatic hydrocarbons in the terrestrial planet-forming region of disks  

Microsoft Academic Search

Interstellar material is highly processed when subjected to the physical conditions that prevail in the inner regions of protoplanetary disks, the potential birthplace of habitable planets. Polycyclic aromatic hydrocarbons (PAHs) are abundant in the interstellar medium, and they have also been observed in the disks around young stars, with evidence for some modification in the latter. Using a chemical model

Monika E. Kress; Alexander G. G. M. Tielens; Michael Frenklach

2010-01-01

441

Development of a Relative Potency Factor (RPF) Approach for Polycyclic Aromatic Hydrocarbon (PAH) Mixtures (Interagency Science Consultation Draft)  

EPA Science Inventory

On February 26, 2010, the draft Development of a Relative Potency Factor (RPF) Approach for Polycyclic Aromatic Hydrocarbon (PAH) Mixtures document and the charge to external peer reviewers were released for external peer review and public comment. The draft document and t...

442

Distribution of polycyclic aromatic hydrocarbons in water, suspended particulate matter and sediment from Daliao River watershed, China  

Microsoft Academic Search

This study investigated the spatial distribution of polycyclic aromatic hydrocarbons (PAHs) in surface water, suspended particulate matter (SPM) and sediment of Daliao River watershed composed of the Hun River, Taizi River, and Daliao River. The sources of PAHs were evaluated employing ratios of specific PAHs compounds and principal component analysis (PCA). The total concentrations of PAHs ranged from 946.1 to

Wei Guo; Mengchang He; Zhifeng Yang; Chunye Lin; Xiangchun Quan; Haozheng Wang

2007-01-01

443

Composition and Origins of Polycyclic Aromatic Hydrocarbons in the Mackenzie River and on the Beaufort Sea Shelf  

Microsoft Academic Search

Polycyclic aromatic hydrocarbon (PAH) concentrations in suspended particulate samples from the Mackenzie River delta and shelf sediments from the Beaufort Sea are higher than expected for a pristine area. Low concentrations of combustion PAHs indicate that anthropogenic inputs are low. Alkyl PAH distributions indicate that a significant component of the lower molecular weight parent (unsubstituted) PAH fraction is petrogenic. The

MARK B. YUNKER; ROBIE W. MACDONALD

1995-01-01

444

Draft Genome Sequence of the Aromatic Hydrocarbon-Degrading Bacterium Sphingobium sp. Strain Ant17, Isolated from Antarctic Soil  

PubMed Central

Here, we present the draft genome sequence of Sphingobium sp. strain Ant17, an aromatic hydrocarbon-degrading bacterium that was isolated from Antarctic oil-contaminated soil. An analysis of this genome can lead to insights into the mechanisms of xenobiotic degradation processes at low temperatures and potentially aid in bioremediation applications. PMID:24723703

Guerrero, Leandro D.; Makhalanyane, Thulani P.; Aislabie, Jackie M.

2014-01-01

445

An experimental investigation into the formation of polycyclic-aromatic hydrocarbons (PAH) from pyrolysis of biomass materials  

Microsoft Academic Search

The formation of polycyclic-aromatic hydrocarbons (PAH) from the pyrolysis of cellulose, pectin, and chlorogenic acid was studied. The primary product, mostly primary volatile tar, was exposed to a higher thermal severity, i.e. high temperatures and long residence times. The reactor setup consisted of a quartz tube with two zones, zone I and II, each heated and controlled separately. Zone I

Thomas McGrath; Ramesh Sharma; Mohammad Hajaligol

2001-01-01

446

MEASUREMENT OF POLYCYCLIC AROMATIC HYDROCARBONS IN SOILS AND SEDIMENTS BY PARTICLE-BEAM/HIGH-PERFORMANCE/LIQUID CHROMATOGRAPHY/MASS SPECTROMETRY  

EPA Science Inventory

An analytical method was developed for the measurement of certain polycyclic aromatic hydrocarbons (PANs) in soils and sediments by particle beam liquid chromatography/mass spectrometry. he method applies to PANs with a molecular weight greater than 220. Samples are prepared by S...

447

PHOTO-INDUCED POLYCYCLIC AROMATIC HYDROCARBON TOXIC POTENTIALS OF NEAR SHORE LARVAL FISH HABITAT IN THE GREAT LAKES, USA  

EPA Science Inventory

Photo-induced toxicity (PIT) of polycyclic aromatic hydrocarbons (PAH) has been documented in laboratory studies for both invertebrate and vertebrate aquatic organisms. PIT has not been verified in field studies for larval fish to date. Filtered water samples and larval fish were...

448

Phototoxicity and Environmental Transformation of Polycyclic Aromatic Hydrocarbons (PAHs)—Light-Induced Reactive Oxygen Species, Lipid Peroxidation, and DNA Damage  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs) are a class of mutagenic and tumorigenic environmental contaminants. Although the mechanisms by which PAHs induce cancer in experimental animals have been extensively studied and the metabolic activation pathways have been determined, the environmental fate of PAHs and the phototoxicity exerted by PAHs, as well as their photoreaction products formed in the environment, have received much

Peter P. Fu; Qingsu Xia; Xin Sun; Hongtao Yu

2012-01-01

449

Origin and significance of aromatic hydrocarbons in giant iron ore deposits of the late Archean Hamersley Basin,  

E-print Network

Origin and significance of aromatic hydrocarbons in giant iron ore deposits of the late Archean for revision 18 November 2002) Abstract Late Archean to earliest Paleoproterozoic shales associated with two reserved. 1. Introduction Minimally metamorphosed (200­300 C) shales of the late Archean Hamersley

Brocks, Jochen J.

450

Stress responses to polycyclic aromatic hydrocarbons in Arabidopsis include growth inhibition and hypersensitive response-like symptoms  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs) are of global environmental concern because they cause many health problems including cancer and inflammation of tissue in humans. Plants are important in removing PAHs from the atmosphere; yet, information on the physiology, cell and molecular biology, and biochemis- try of PAH stress responses in plants is lacking. The PAH stress response was studied in Arabidopsis

Merianne Alkio; Tomoko M. Tabuchi; Xuchen Wang; Adan Colon-Carmona

2010-01-01

451

Polycyclic aromatic hydrocarbon contamination of American lobster, Homarus americanus , in the proximity of a coal-coking plant  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAH) are ubiquitous environmental contaminants resulting predominantly from anthropogenic pyrolytic and combustion processes (NRCC 1983). In addition to the usual methods of aerial and aqueous transport to the coastal marine environment substantial amounts of PAH are added through the use of products such as creosote, coal tar and coal tar pitch as preservative and antifouling agents in

J. F. Uthe; C. J. Musial

1986-01-01

452

Polycyclic aromatic hydrocarbons in olive fruits as a measure of air pollution in the valley of Florence (Italy)  

Microsoft Academic Search

Plants have often been used for monitoring air pollution, such as Tradescantia for detecting mutagenic chemicals, or mosses which are bio-accumulators of heavy metals. Mosses have also been used as indicators of pollution from hexachlorobenzene and polycyclic aromatic hydrocarbons. PAH are present in most crops, and are deposited on the foliar surface of plants exposed to polluted air. Plants grown

Giovanni Ignesti; Maura Lodovici; Piero Dolara; Pagliai Lucia; Daniele Grechi

1992-01-01

453

Solidphase microextraction for determining the distribution of sixteen US Environmental Protection Agency polycyclic aromatic hydrocarbons in water samples  

Microsoft Academic Search

A solid-phase microextraction (SPME) procedure has been developed for the determination of 16 US Environmental Protection Agency promulgated polycyclic aromatic hydrocarbons (PAHs). Five kinds of SPME fibers were used and compared in this study. The extracted sample was analyzed by gas chromatography with flame ionization detection or mass spectrometry. Parameters affecting the sorption of analyte into the fibers, including sampling

Ruey-an Doong; Sue-min Chang; Yuh-chang Sun

2000-01-01

454

Exposure to genotoxins present in ambient air in Bangkok, Thailand — particle associated polycyclic aromatic hydrocarbons and biomarkers  

Microsoft Academic Search

Exposure to genotoxic compounds in ambient air has been studied in Bangkok, Thailand, by analysis of polycyclic aromatic hydrocarbons (PAHs) associated with particles and using different biomarkers of exposure. Eighty-nine male, non-smoking Royal Thai police officers were investigated. The police officers were divided into a high exposure group (traffic police) and low exposure (office duty). Particulate matter was collected using

Mathuros Ruchirawat; Chulabhorn Mahidol; Chanthana Tangjarukij; Sittisak Pui-ock; Ole Jensen; Ormrat Kampeerawipakorn; Jantamas Tuntaviroon; Aurata