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1

Polycyclic aromatic hydrocarbons in dust from computers : one possible indoor source of human exposure  

NASA Astrophysics Data System (ADS)

Computer is an important part of our usual life and work. The harmful exposure to the radiation of computers has been paid attention broadly. However, chemical pollution related to computers is rarely reported. Here we investigated the levels and sources of EPA 16 priority polycyclic aromatic hydrocarbons (PAHs) in dust samples collected from components and internal walls of computers' boxes (in-computers) in Shanghai, China. Dust samples were collected from 27 computers in different indoor environment: offices, laboratories, and one net bar. The levels of PAHs in dust samples were from 8.22 ?g g -1 to 42.04 ?g g -1. BbF, BgP, DbA, Chry and BaP were the most abundant PAHs. The levels of PAHs in computers in smoking rooms (mainly in the net bar) were usually 1.35-2.87 times higher than those in nonsmoking rooms, indicating that the indoor environment of different rooms affected the loading of dust PAHs significantly. To study the source of PAHs in computers, six dust samples were collected from windowsills (out-computers) in the corresponding rooms. The results indicated that most PAHs from in-computers were greater than those from out-computers, which indicated that parts of PAHs in computers may be emitted from the heated plastic material out of chips in computers when they are running, and be adsorbed on dust deposited on these components. The potential exposure of PAHs from computers was also evaluated, and our results showed that people maybe exposure particle-phase PAHs up to 2.99 ng m -3 which are just sprayed out with dust from computers.

Ren, Yu; Cheng, Tiantao; Chen, Jianmin

2

Emission of oxygenated polycyclic aromatic hydrocarbons from indoor solid fuel combustion.  

PubMed

Indoor solid fuel combustion is a dominant source of polycyclic aromatic hydrocarbons (PAHs) and oxygenated PAHs (OPAHs) and the latter are believed to be more toxic than the former. However, there is limited quantitative information on the emissions of OPAHs from solid fuel combustion. In this study, emission factors of OPAHs (EF(OPAH)) for nine commonly used crop residues and five coals burnt in typical residential stoves widely used in rural China were measured under simulated kitchen conditions. The total EF(OPAH) ranged from 2.8 ± 0.2 to 8.1 ± 2.2 mg/kg for tested crop residues and from 0.043 to 71 mg/kg for various coals and 9-fluorenone was the most abundant specie. The EF(OPAH) for indoor crop residue burning were 1-2 orders of magnitude higher than those from open burning, and they were affected by fuel properties and combustion conditions, like moisture and combustion efficiency. For both crop residues and coals, significantly positive correlations were found between EFs for the individual OPAHs and the parent PAHs. An oxygenation rate, R(o), was defined as the ratio of the EFs between the oxygenated and parent PAH species to describe the formation potential of OPAHs. For the studied OPAH/PAH pairs, mean R(o) values were 0.16-0.89 for crop residues and 0.03-0.25 for coals. R(o) for crop residues burned in the cooking stove were much higher than those for open burning and much lower than those in ambient air, indicating the influence of secondary formation of OPAH and loss of PAHs. In comparison with parent PAHs, OPAHs showed a higher tendency to be associated with particulate matter (PM), especially fine PM, and the dominate size ranges were 0.7-2.1 ?m for crop residues and high caking coals and <0.7 ?m for the tested low caking briquettes. PMID:21375317

Shen, Guofeng; Tao, Shu; Wang, Wei; Yang, Yifeng; Ding, Junnan; Xue, Miao; Min, Yujia; Zhu, Chen; Shen, Huizhong; Li, Wei; Wang, Bin; Wang, Rong; Wang, Wentao; Wang, Xilong; Russell, Armistead G

2011-04-15

3

Polycyclic aromatic hydrocarbons and their derivatives in indoor and outdoor air in an eight-home study  

NASA Astrophysics Data System (ADS)

A pilot field study was performed in Columbus, OH, during the winter of 1986/1987. The objectives were to determine the feasibility of the use of a newly developed quiet sampler in indoor air sampling for particles and semivolatile organic compounds (SVOC) and to measure the concentrations of polycyclic aromatic hydrocarbons (PAH), PAH derivatives, and nicotine in air in selected residences. Eight homes were chosen for sampling on the basis of these characteristics: electric/gas heating system, electric/gas cooking appliances, and the absence/presence of environmental tobacco smoke (ETS). The indoor sampler was equipped with a quartz-fiber filter to collect particles followed by XAD-4 resin to trap SVOC. A PS-1 sampler with a similar sampling module was used outdoors. The indoor air was sampled in the kitchen and living room areas over two consecutive 8-h periods. The outdoor air was sampled concurrently with the indoor samples over a 16-h period. Fifteen PAH, five nitro-PAH, five oxygenated PAH, and three nitrogen heterocyclic compounds were determined in these samples. The most abundant PAH found indoors was naphthalene. The indoor concentrations of PAH derivatives were lower than those of their parent compounds. Average concentrations of all but three target compounds (naphthalene dicarboxylic acid anhydride, pyrene dicarboxylic acid anhydride, and 2-nitrofluoranthene) were higher indoors than outdoors. Environmental tobacco smoke was the most significant influence on indoor pollutant levels. Homes with gas heating systems had higher indoor pollutant levels than homes with electric heating systems. However, the true effects of heating and cooking systems were not characterized as accurately as the effects of ETS because of the small sample sizes and the lack of statistical significance for most pollutant differences in the absence of ETS. The concentrations of PAH marker compounds (phenanthrene, fluoranthene, and pyrene) correlated well with the concentrations of other target compounds. Quinoline and isoquinoline can be used to indicate indoor levels of ETS.

Chuang, Jane C.; Mack, Gregory A.; Kuhlman, Michael R.; Wilson, Nancy K.

4

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

5

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 ...

6

Characterization of particulate and vapor phase polycyclic aromatic hydrocarbons in indoor and outdoor air of primary schools  

NASA Astrophysics Data System (ADS)

The indoor air of schools is considered as one of the most important factors affecting the health of children. The aim of the presented research was to characterize polycyclic aromatic hydrocarbons (PAHs) in indoor and outdoor air of schools. The sampling campaign was conducted during the heating season of 2011/2012. Five primary schools from various urban settings in the city of Kaunas, Lithuania. 150 daily samples of particulate and vapor phases were collected during the sampling period. The ultrasonic extractions followed by the gas chromatography and mass spectroscopy (GS/MS) analyses were used for the determination of PAHs. The concentration of total PAHs in the PM2.5 fraction ranged from 20.3 to 131.1 ng m-3, while total suspended particles (TSP) fraction contained from 19.9 to 80.3 ng m-3 of total PAHs. The vapor phase concentration of PAHs ranged from 67.2 to 372.5 ng m-3. The most abundant PAH in both phases was naphthalene. In order to define sources of indoor and outdoor PAHs several source apportionment methods were applied. The analysis revealed that emissions from motor vehicles and fuel burning for heating purposes were the major sources of PAHs in the city of Kaunas.

Krugly, Edvinas; Martuzevicius, Dainius; Sidaraviciute, Ruta; Ciuzas, Darius; Prasauskas, Tadas; Kauneliene, Violeta; Stasiulaitiene, Inga; Kliucininkas, Linas

2014-01-01

7

Emissions of parent, nitrated, and oxygenated polycyclic aromatic hydrocarbons from indoor corn straw burning in normal and controlled combustion conditions.  

PubMed

Emission factors (EFs) of parent polycyclic aromatic hydrocarbons (pPAHs), nitrated PAHs (nPAHs), and oxygenated PAHs (oPAHs) were measured for indoor corn straw burned in a brick cooking stove under different burning conditions. The EFs of total 28 pPAHs, 6 nPAHs and 4 oPAHs were (7.9 +/- 3.4), (6.5 +/- 1.6) x 10(-3), and (6.1 +/- 1.4) x 10(-1) mg/kg, respectively. Fuel charge size had insignificant influence on the pollutant emissions. Measured EFs increased significantly in a fast burning due to the oxygen deficient atmosphere formed in the stove chamber. In both restricted and enhanced air supply conditions, the EFs of pPAHs, nPAHs and oPAHs were significantly higher than those measured in normal burning conditions. Though EFs varied among different burning conditions, the composition profiles and calculated isomer ratios were similar, without significant differences. The results from the stepwise regression model showed that fuel burning rate, air supply amount, and modified combustion efficiency were the three most significant influencing factors, explaining 72%-85% of the total variations. PMID:24494494

Shen, Guofeng; Xue, Miao; Wei, Siye; Chen, Yuanchen; Wang, Bin; Wang, Rong; Lv, Yan; Shen, Huizhong; Li, Wei; Zhang, Yanyan; Huang, Ye; Chen, Han; Wei, Wen; Zhao, Qiuyue; Li, Bing; Wu, Haisuo; Tao, Shu

2013-10-01

8

Population inhalation exposure to polycyclic aromatic hydrocarbons and associated lung cancer risk in Beijing region: Contributions of indoor and outdoor sources and exposures  

NASA Astrophysics Data System (ADS)

Polycyclic aromatic hydrocarbons (PAHs) are among the most toxic air pollutants in China. Efforts in assessing population inhalation exposure to PAHs, and its contribution to lung cancer risk for Chinese residents, have been limited due to insufficient data on measured indoor concentrations. A mass-balance model to predict indoor PAH concentrations was developed, along with estimated exposures and attributable lung cancer risks for residents in the Beijing region in 2006, with a 2-stage Monte Carlo simulation framework. The exposures and risks were split into three parts, based on the sources and places of exposure, to estimate the contributions of indoor and outdoor PAH sources and exposures, in order to better understand the source and place pattern of PAH exposure. PAHs bring considerable lung cancer risk to the population of Beijing region. The population attributable fraction (PAF) of lung cancer for Beijing's overall population is 2.99% [95% confidence interval (CI): 1.71%-4.26%]. Median contribution of indoor exposure to outdoor-originated PAHs (OUT-in) is 78% (CI: 73%-81%) in the overall population, for 97% (CI: 94%-99%) of whom OUT-in is the largest contributor. Rural residents are facing considerable exposure to indoor-originated PAHs (IN-in), which dominates the total exposure in 12% (CI: 2%-24%) of the rural population. This model framework could be used in quantitative comparison of different interventions on exposure to PAHs as well as other airborne pollutants.

Zhou, Bin; Zhao, Bin

2012-12-01

9

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.

10

Assessment of Benzo(a)pyrene-equivalent Carcinogenicity and Mutagenicity of Residential Indoor versus Outdoor Polycyclic Aromatic Hydrocarbons Exposing Young Children in New York City  

PubMed Central

The application of benzo(a)pyrene (BaP)-toxic equivalent factor to polycyclic aromatic hydrocarbons (PAH) concentrations can provide a more accurate risk assessment from environmental exposure to PAH. We hypothesized that BaP-equivalent toxicity determined following residential air monitoring among young urban children may vary by season. Residential indoor and outdoor air levels of PAH measured over two-weeks in a cohort of 5–6 year old children (n = 260) in New York City were normalized to the cancer and mutagen potency equivalent factor of BaP (BaP = 1). Data are presented as carcinogenic equivalents (BaP-TEQ) and mutagenic equivalents (BaP-MEQ) for the sum of 8 PAH (?8PAH; MW ? 228) and individual PAH and compared across heating versus nonheating seasons. Results show that heating compared to nonheating season was associated significantly with higher (BaP-TEQ)?8PAH and (BaP-MEQ)?8PAH both indoors and outdoors (p < 0.001). Outdoor (BaP-TEQ)?8PAH and (BaP-MEQ)?8PAH were significantly higher than the corresponding indoor measures during the heating season (p < 0.01). These findings suggest that at levels encountered in New York City air, especially during the heating season, residential exposure to PAH may pose an increased risk of cancer and mutation. PMID:20622999

Jung, Kyung Hwa; Yan, Beizhan; Chillrud, Steven N.; Perera, Frederica P.; Whyatt, Robin; Camann, David; Kinney, Patrick L.; Miller, Rachel L.

2010-01-01

11

Participant-based monitoring of indoor and outdoor nitrogen dioxide, volatile organic compounds, and polycyclic aromatic hydrocarbons among MICA-Air households  

NASA Astrophysics Data System (ADS)

The Mechanistic Indicators of Childhood Asthma (MICA) study in Detroit, Michigan introduced a participant-based approach to reduce the resource burden associated with collection of indoor and outdoor residential air sampling data. A subset of participants designated as MICA-Air conducted indoor and outdoor residential sampling of nitrogen dioxide (NO 2), volatile organic compounds (VOCs), and polycyclic aromatic hydrocarbons (PAHs). This participant-based methodology was subsequently adapted for use in the Vanguard phase of the U.S. National Children's Study. The current paper examines residential indoor and outdoor concentrations of these pollutant species among health study participants in Detroit, Michigan. Pollutants measured under MICA-Air agreed well with other studies and continuous monitoring data collected in Detroit. For example, NO 2 and BTEX concentrations reported for other Detroit area monitoring were generally within 10-15% of indoor and outdoor concentrations measured in MICA-Air households. Outdoor NO 2 concentrations were typically higher than indoor NO 2 concentration among MICA-Air homes, with a median indoor/outdoor (I/O) ratio of 0.6 in homes that were not impacted by environmental tobacco smoke (ETS) during air sampling. Indoor concentrations generally exceeded outdoor concentrations for VOC and PAH species measured among non-ETS homes in the study. I/O ratios for BTEX species (benzene, toluene, ethylbenzene, and m/p- and o-xylene) ranged from 1.2 for benzene to 3.1 for toluene. Outdoor NO 2 concentrations were approximately 4.5 ppb higher on weekdays versus weekends. As expected, I/O ratios pollutants were generally higher for homes impacted by ETS. These findings suggest that participant-based air sampling can provide a cost-effective alternative to technician-based approaches for assessing indoor and outdoor residential air pollution in community health studies. We also introduced a technique for estimating daily concentrations at each home by weighting 2- and 7-day integrated concentrations using continuous measurements from regulatory monitoring sites. This approach may be applied to estimate short-term daily or hourly pollutant concentrations in future health studies.

Johnson, Markey M.; Williams, Ron; Fan, Zhihua; Lin, Lin; Hudgens, Edward; Gallagher, Jane; Vette, Alan; Neas, Lucas; Özkaynak, Halûk

2010-12-01

12

A wintertime study of polycyclic aromatic hydrocarbons (PAHs) in indoor and outdoor air in a big student residence in Algiers, Algeria.  

PubMed

The wintertime concentrations and diel cycles of n-alkanes and polycyclic aromatic hydrocarbons (PAHs) associated to atmospheric particulate matter with aerodynamic diameter lesser than 10 ?m were determined at the biggest student residence in Algeria located in Bab-Ezzouar, 15 km southeast from Algiers city area. Samplings were carried out from December 2009 to March 2010, and organic compounds were characterized using gas chromatography coupled with mass spectrometric detection. Volatile PAHs were also monitored inside some student residence rooms in order to evaluate the impact of indoor air pollution to student health. For the sake of comparison, aerial concentrations of n-alkanes and PAHs were determined in parallel in the Oued Smar industrial zone and two suburban areas, all located in Algiers. Total concentrations recorded in CUB1 student residence ranged from 101 to 204 ng?m(-3) for n-alkanes and from 8 to 87 ng?m(-3) for PAHs. Diel cycles have shown that, while concentrations of n-alkanes peaked at morning and afternoon-evening and dropped at night, those of PAHs exhibited higher levels at morning and night and lower levels at afternoon-evening, likely due to the reactivity of some PAHs. As expected, the indoor levels of PAHs were larger than in the outdoor of the student residence and were of serious health concern. Overall, the concentrations of n-alkanes and PAHs were as high as those observed in the industrial zone and higher than the two suburban sites. PMID:23314704

Khedidji, Sidali; Ladji, Riad; Yassaa, Noureddine

2013-07-01

13

Effects of Heating Season on Residential Indoor and Outdoor Polycyclic Aromatic Hydrocarbons, Black Carbon, and Particulate Matter in an Urban Birth Cohort  

PubMed Central

Exposure to air pollutants has been associated with adverse health effects. However, analyses of the effects of season and ambient parameters such as ozone have not been fully conducted. Residential indoor and outdoor air levels of polycyclic aromatic hydrocarbons (PAH), black carbon (measured as absorption coefficient [Abs]), and fine particulate matter <2.5 ?m (PM)2.5 were measured over two-weeks in a cohort of 5–6 year old children (n=334) living in New York City’s Northern Manhattan and the Bronx between October 2005 and April 2010. The objectives were to: 1) characterize seasonal changes in indoor and outdoor levels and indoor/outdoor (I/O) ratios of PAH (gas + particulate phase; dichotomized into ?8PAHsemivolatile (MW 178–206), and ?8PAHnonvolatile (MW 228–278)), Abs, and PM2.5; and 2) assess the relationship between PAH and ozone. Results showed that heating compared to nonheating season was associated with greater ?8PAHnonvolatile (p<0.001) and Abs (p<0.05), and lower levels of ?8PAHsemivolatile (p<0.001). In addition, the heating season was associated with lower I/O ratios of ?8PAHnonvolatile and higher I/O ratios of ?8PAHsemivolatile (p<0.001) compared to the nonheating season. In outdoor air, ?8PAHnonvolatile was correlated negatively with community-wide ozone concentration (p<0.001). Seasonal changes in emission sources, air exchanges, meteorological conditions and photochemical/chemical degradation reactions are discussed in relationship to the observed seasonal trends. PMID:20938487

Jung, Kyung Hwa; Patel, Molini M.; Moors, Kathleen; Kinney, Patrick L.; Chillrud, Steven N.; Whyatt, Robin; Hoepner, Lori; Garfinkel, Robin; Yan, Beizhan; Ross, James; Camann, David; Perera, Frederica P.; Miller, Rachel L.

2010-01-01

14

Evaluation of sampling and analytical methods for nicotine and polynuclear aromatic hydrocarbon in indoor air. Final report, 1 February 1987-30 March 1987  

SciTech Connect

The objective of this 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 in air. The extraction efficiency study was to determine the extraction method to quantitatively remove nicotine and PAH from XAD-4 resin. The results showed that a two-step Soxhlet extraction consisting of dichloromethane followed by ethyl acetate resulted in the best recoveries for both nicotine and PAH. In the sampling efficiency study, XAD-2 and XAD-4 resin were compared, in parallel, for collection of PAH and nicotine. Quartz fiber filters were placed upstream of both adsorbents to collect particles. Prior to sampling, both XAD-2 and XAD-4 traps were spiked with known amounts (2 microgram) of perdeuterated PAH and D3-nicotine. The experiments were performed with cigarette smoking and nonsmoking conditions. The spiked PAH were retained well in both adsorbents after exposure to more than 300 cu. m. of indoor air. The spiked XAD-4 resin gave higher recoveries for D3-nicotine than did the spiked XAD-2 resin. The collection efficiency for PAH for both adsorbents is very similar but higher levels of nicotine were collected on XAD-4 resin.

Chuang, J.C.; Kuhlman, M.R.; Hannan, S.W.; Bridges, C.

1987-11-01

15

POLYCYCLIC AROMATIC HYDROCARBONS AND THEIR DERIVATIVES IN INDOOR AND OUTDOOR AIR IN AND EIGHT-HOME STUDY  

EPA Science Inventory

A pilot field study was performed in Columbus, Ohio during the winter of 1986/1987. he objectives were to determine the feasibility of the use of a newly developed quiet sampler in indoor air sampling for particles and semivolatile organic compounds (SVOCs), and to estimate the r...

16

Indoor-outdoor levels of size segregated particulate matter and mono/polycyclic aromatic hydrocarbons among urban areas using solid fuels for heating  

NASA Astrophysics Data System (ADS)

Emissions from the fuel combustion in the energy production are causes of concern due to associated health risks, but little information is available on the impact of residential fuel burning on indoor air quality, where most of the human exposure occurs. In this complex study, concentrations of size-segregated particulate matter (PM), monocyclic and polycyclic aromatic compounds (MAHs and PAHs) at indoor and outdoor sites in six urban homes in the city of Kaunas, Lithuania, were determined over winter and summer sampling campaigns, specifically targeting the impact of the local fuel burning to the indoor air quality. PM levels observed in Kaunas during winter measurement campaign were higher compared to those in many other European settlements utilizing biomass for energy production. The particle size distribution analysis revealed that the major part of the PM mass in winter period consisted of fine particles (PM2.5). Both MAH and PAH levels were higher in winter. The indoor to outdoor ratios (I/O) of MAHs and PAHs revealed specific patterns depending on the presence of emissions sources indoors. Irrespectively of the season, I/O values were <1, suggesting that in case of the absence of an indoor pollution, the dominant source of organic compounds was from the outdoor environment. In homes with no PAH source inside, the I/O ratio equalled ranged from 0.05 to 0.36, suggesting the penetrated portion of outdoor combustion particles to the indoor air.

Kliucininkas, Linas; Krugly, Edvinas; Stasiulaitiene, Inga; Radziuniene, Inga; Prasauskas, Tadas; Jonusas, Arunas; Kauneliene, Violeta; Martuzevicius, Dainius

2014-11-01

17

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...

18

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...

19

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 ...

20

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

21

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

22

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

23

ANALYTICAL AND SAMPLING METHODOLOGY FOR CHARACTERIZATION OF POLYNUCLEAR AROMATIC COMPOUNDS IN INDOOR AIR  

EPA Science Inventory

Sampling and analysis methodology were developed for the collection and quantification of polynuclear aromatic hydrocarbons, their nitro derivatives, and their nitrogen heterocyclic analogs in indoor air. The methodology was evaluated in a study of air in ten homes. The study inc...

24

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

25

Polycyclic aromatic hydrocarbons in gas and particulate phases of indoor environments influenced by tobacco smoke: Levels, phase distributions, and health risks  

NASA Astrophysics Data System (ADS)

As polycyclic aromatic hydrocarbons (PAHs) have a negative impact on human health due to their mutagenic and/or carcinogenic properties, the objective of this work was to study the influence of tobacco smoke on levels and phase distribution of PAHs and to evaluate the associated health risks. The air samples were collected at two homes; 18 PAHs (the 16 PAHs considered by U.S. EPA as priority pollutants, dibenzo[a,l]pyrene and benzo[j]fluoranthene) were determined in gas phase and associated with thoracic (PM 10) and respirable (PM 2.5) particles. At home influenced by tobacco smoke the total concentrations of 18 PAHs in air ranged from 28.3 to 106 ng m -3 (mean of 66.7 ± 25.4 ng m -3), ? PAHs being 95% higher than at the non-smoking one where the values ranged from 17.9 to 62.0 ng m -3 (mean of 34.5 ± 16.5 ng m -3). On average 74% and 78% of ? PAHs were present in gas phase at the smoking and non-smoking homes, respectively, demonstrating that adequate assessment of PAHs in air requires evaluation of PAHs in both gas and particulate phases. When influenced by tobacco smoke the health risks values were 3.5-3.6 times higher due to the exposure of PM 10. The values of lifetime lung cancer risks were 4.1 × 10 -3 and 1.7 × 10 -3 for the smoking and non-smoking homes, considerably exceeding the health-based guideline level at both homes also due to the contribution of outdoor traffic emissions. The results showed that evaluation of benzo[a]pyrene alone would probably underestimate the carcinogenic potential of the studied PAH mixtures; in total ten carcinogenic PAHs represented 36% and 32% of the gaseous ? PAHs and in particulate phase they accounted for 75% and 71% of ? PAHs at the smoking and non-smoking homes, respectively.

Castro, Dionísia; Slezakova, Klara; Delerue-Matos, Cristina; Alvim-Ferraz, Maria da Conceição; Morais, Simone; Pereira, Maria do Carmo

2011-04-01

26

Participant-Based Monitoring of Indoor and Outdoor Nitrogen Dioxide, Volatile Organic Compounds, and Polycyclic Aromatic Hydrocarbons among MICA-Air Households  

EPA Science Inventory

The Mechanistic Indicators of Childhood Asthma (MICA) study in Detroit, Michigan introduced a participant-based approach to reduce the resource burden associated with collection of indoor and outdoor residential air sampling data. A subset of participants designated as MICA-Air c...

27

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.

28

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.

29

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

30

Polycyclic Aromatic Hydrocarbons in Indoor Air and EnvironmentalTobacco Smoke Measured with a New Integrated Organic Vapor-ParticleSampler  

SciTech Connect

Sampling details. The novel aspect of the sampling equipment is the use of ground XAD-4 resin as a coating for annular denuders. Figure 1 shows a schematic diagram of one sampling configuration used for field testing the IOVPS in indoor air and ETS. Commercially available, single-channel glass denuders, 22 cm long, with a 1 mm annulus (University Research Glass, Carrboro, NC, USA were used with a Teflon- ) lined aluminum cyclone (cutoff 2.5 microns at 10 L mine ) preceding the first denuder. Three XAD-4-coated denuders were connected in series between the cyclone and a Teflon filter pack which contained a pre-extracted and pre-weighed Teflon-coated glass-fiber filter. (The three-denuder configuration was used for determining breakthrough of naphthalene and its methyl derivatives as a function of flow rate.) In some experiments, a coated denuder followed the filter pack. The parallel sorbent bed sampler used an aluminum open-face filter holder with a Teflon-coated glass-fiber filter, followed by a glass tube packed with 2.5 g cleaned XAD-4 resin. Flow rates, measured with a dry gas test meter, were 5, 10 and 20 L min-1 for field testing; sampling times varied from 3 to 22 hours. Indoor air with no combustion sources was sampled in an unoccupied room. Diluted sidestream smoke was sampled as a surrogate for ETS in an unventilated 20 m3 chamber at 5 L rnin-l for hour-long periods while a single-port smoking machine smoked 3 cigarettes. Ambient temperature varied between 22 and 26 C.

Gundel, L.A.; Daisey, J.M.; Mahanama, K.R.R.; Lee, C.C.; Stevens,R.K.

1993-01-01

31

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

32

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

33

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...

34

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...

35

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). ...

36

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...

37

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

38

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

39

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

40

Assessing indoor air exposures using passive sampling with bioanalytical methods for estrogenicity and aryl hydrocarbon receptor activity  

PubMed Central

Passive air sampling was undertaken using polyurethane foam passive air samplers at three types of locations, including indoors (six offices) at buildings in the central business district (CBD) and at a private suburban home (indoor and outdoor) located 9 km from the CBD in Brisbane, Queensland, Australia. Estrogenic (E-SCREEN—MCF7-BOS) and aryl hydrocarbon receptor (AhR) (CAFLUX— H4G1.1c2) activity were assessed for samples collected from each of these locations. The samples were tested either as crude extracts (“untreated”) or were subjected to H2SO4 silica gel (“treated”) for each location in order to determine whether chemicals, which are not resistant to this treatment like polycyclic aromatic hydrocarbons, potentially account for the observed activity. In most cases, H2SO4 treatment resulted in a statistically significant reduction of potency for both endpoints, suggesting that chemicals less resistant to treatment may be responsible for much of the detected biological activity in these locations. Estrogenic potency measurements (<0.22–185 pg m?3) were highest in the indoor offices, followed by the indoor suburban home and finally the outdoor suburban home (which was not estrogenic). Total AhR activity for crude extracts (1.3–10 pg m?3) however was highest for the outdoor suburban home site. Levels of polycyclic aromatic hydrocarbons were monitored indoors and outdoors at the suburban home. At that location, polycyclic aromatic hydrocarbon air concentrations were on average approximately two times higher outdoor than indoor, while AhR potency was five times higher outdoor than indoor. No significant correlation was found between the estrogenic and AhR activity (P=0.88) for the sites in this study. PMID:19430962

Macova, Miroslava; Leusch, Frederic; Bartkow, Michael E.; Hawker, Darryl W.; Zhao, Bin; Denison, Michael S.; Mueller, Jochen F.

2010-01-01

41

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...

42

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...

43

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

44

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...

45

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....

46

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...

47

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

48

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

49

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

50

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

51

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

52

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

53

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

54

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

55

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.

56

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

57

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

58

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

59

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

60

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

61

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

62

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

63

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

64

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

65

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

66

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

67

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

68

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...

69

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

70

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

71

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...

72

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

73

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

74

SCREENING POLYNUCLEAR AROMATIC POLLUTANTS IN AMBIENT AND INDOOR AIR BY SYNCHRONOUS LUMINESCENCE  

EPA Science Inventory

Polynuclear aromatic (PNA) pollutants are of concern in indoor and outdoor air monitoring because many PNAs are carcinogenic in laboratory animal biotesting. For comprehensive exposure studies, which usually involve large population distributions and extended assessment periods (...

75

Screening Polynuclear Aromatic Pollutants in Ambient and Indoor Air by Synchronous Luminescence.  

National Technical Information Service (NTIS)

Polynuclear aromatic (PNA) pollutants are of concern in indoor and outdoor air monitoring because many PNAs are carcinogenic in laboratory animal biotesting. For comprehensive exposure studies, which usually involve large population distributions and exte...

T. Vo-Dinh, G. H. Miller, N. K. Wilson

1986-01-01

76

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

77

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

78

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.

79

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

80

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

81

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

82

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

83

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

84

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

85

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

86

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

87

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

88

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

89

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

90

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

91

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

92

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

93

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

94

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

95

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

96

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

97

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

98

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

99

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

100

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

101

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

102

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

103

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

104

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

105

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

106

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

107

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

108

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

109

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

110

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.

111

Exploratory study of particle-bound polycyclic aromatic hydrocarbons in different environments of Mexico City  

NASA Astrophysics Data System (ADS)

Several studies regarding particulate matter in air pollution have been performed in Mexico City, but none have focused on environment exposure to particle-bound polycyclic aromatic hydrocarbons (PPAH), which are related to the occurrence of cardiopulmonary diseases and mortality. On this account, this study presents measurements of personal exposure to PPAH in different outdoor and indoor environments, as well as along roadways in Mexico City. The measurements were done with portable sensors based on photoelectric charging and diffusion charging to determine the PPAH concentrations and the joint active surface of all particles, respectively. The use of these two sensors in parallel is a useful tool to qualitatively identify the major sources and to describe the physical and chemical characteristics of the particles. The highest exposures were found in ambient air near traffic sources, mainly at sites with great influence of diesel vehicles, such as urban transfer bus stations. Roadway measurements showed that Mexican PPAH pollution levels are between those in large cities in Europe and USA. For indoor environments such as residences, shopping centers, restaurants and hospitality venues, it was found that secondhand smoke is the major contributor, however badly calibrated pilot stoves, inefficient ventilation and faulty air-conditioning systems can be additional sources of PPAH.

Velasco, Erik; Siegmann, Philip; Siegmann, Hans C.

112

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

113

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...

114

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

115

Isolation and screening of black fungi as degraders of volatile aromatic hydrocarbons.  

PubMed

Black fungi reported as degraders of volatile aromatic compounds were isolated from hydrocarbon-polluted sites and indoor environments. Several of the species encountered are known opportunistic pathogens or are closely related to pathogenic species causing severe mycoses, among which are neurological infections in immunocompetent individuals. Given the scale of the problem of environmental pollution and the phylogenetic relation of aromate-degrading black fungi with pathogenic siblings, it is of great interest to select strains able to mineralize these substrates efficiently without any risk for public health. Fifty-six black strains were obtained from human-made environments rich in hydrocarbons (gasoline car tanks, washing machine soap dispensers) after enrichment with some phenolic intermediates of toluene and styrene fungal metabolism. Based on ITS sequencing identification, the majority of the obtained isolates were members of the genus Exophiala. Exophiala xenobiotica was found to be the dominant black yeast present in the car gasoline tanks. A higher biodiversity, with three Exophiala species, was found in soap dispensers of washing machines. Strains obtained were screened using a 2,6-dichlorophenol-indophenol (DCPIP) assay, optimized for black fungi, to assess their potential ability to degrade toluene. Seven out of twenty strains tested were able to use toluene as carbon source. PMID:23475324

Isola, Daniela; Selbmann, Laura; de Hoog, G Sybren; Fenice, Massimiliano; Onofri, Silvano; Prenafeta-Boldú, Francesc X; Zucconi, Laura

2013-06-01

116

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

117

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

118

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.

119

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

120

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

121

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

122

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

123

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

124

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

125

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

126

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

127

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

128

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

129

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

130

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

131

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

132

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

133

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

134

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

135

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

136

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

137

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...

138

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...

139

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...

140

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

141

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...

142

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...

143

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

144

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

145

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...

146

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

147

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 ...

148

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...

149

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

150

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

151

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

152

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

153

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

154

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

155

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

156

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

157

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

158

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

159

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

160

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

161

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

162

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

163

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

164

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

165

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

166

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

167

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

168

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

169

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

170

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

171

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

172

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

173

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

174

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

175

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

176

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

177

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

178

Direct determination of the phase distributions of semi-volatile polycyclic aromatic hydrocarbons using annular denuders  

NASA Astrophysics Data System (ADS)

An annular denuder-based sampler, here called the integrated organic vapor/particle sampler (IOVPS), has been developed for direct determination of both gaseous and particulate semi-volatile organic species. The IOVPS uses a cyclone inlet for removal of particles greater than 2.5 ?m (D 50) from the airstream, followed by two or three sandblasted glass annular denuders coated with ground particles of an adsorbent resin. The denuders trap the gas-phase species of interest before the airstream passes through a filter and a backup denuder. Extracts of the denuders and filters are analyzed for the semi-volatile species of interest. The IOVPS has been tested and validated for sampling semi-volatile polycyclic aromatic hydrocarbons (PAH) in indoor laboratory room air and environmental tobacco smoke (ETS). Ground XAD-4 was the adsorbent for these initial studies. Gas- and particulate-phase concentrations of semi-volatile PAH are presented for these two environments. The new sampler provides the means for directly determining phase distributions of PAH and other classes of semi-volatile organic species, rather than by difference or by techniques that are subject to large positive and negative artifacts.

Gundel, Lara A.; Lee, Victor C.; Mahanama, Kariyawasam R. R.; Stevens, Robert K.; Daisey, Joan M.

179

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

180

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

181

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

182

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

183

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

184

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

185

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

186

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

187

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

188

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

189

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

190

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

191

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

192

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

193

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

194

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

195

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, ...

196

Real-time monitoring of polycyclic aromatic hydrocarbons and respirable suspended particles from environmental tobacco smoke in a home  

SciTech Connect

Real-time measurement of polycyclic aromatic hydrocarbons (PAH) on fine particles was evaluated in a home with environmental tobacco smoke (ETS) as a source. Respirable suspended particles (RSP) were also monitored. Comparison of PAH and RSP concentrations from these experiments suggests: (1) the PAH concentrations for the two types of cigarettes--a regular Marlboro filter cigarette and a University of Kentucky reference cigarette No. 2R1--were similar, but the RSP concentrations were different; (2) concentrations from the real-time PAH monitor were linearly related to RSP concentrations; (3) the slopes of the regression lines between PAH and RSP differed for the two types of cigarettes. The real-time PAH monitor appears to be a useful tool for evaluating mathematical models to predict the concentration time series in indoor microenvironments.

Ott, W.; Wilson, N.K.; Klepeis, N.; Switzer, P.

1994-01-01

197

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

198

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

199

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

200

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

201

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

202

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

203

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

204

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

205

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

206

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

207

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

208

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

209

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

210

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

211

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

212

Predictors of personal polycyclic aromatic hydrocarbon exposures among pregnant minority women in New York City.  

PubMed Central

As part of a multiyear birth-cohort study examining the roles of pre- and postnatal environmental exposures on developmental deficits and asthma among children, we measured personal exposures to polycyclic aromatic hydrocarbons (PAHs) among 348 pregnant women in northern Manhattan and the South Bronx, New York. Nonsmoking African-American or Dominican women were identified and recruited into the study. During the third trimester of pregnancy, each subject wore a personal air monitor for 48 hr to determine exposure levels to nine PAH compounds. In this study, we examined levels of exposures to PAHs and tested for associations with potential predictor variables collected from questionnaires addressing socioeconomic factors and day-to-day activities during pregnancy as well as activities and environmental exposures during the 48-hr monitoring period. Reliable personal monitoring data for women who did not smoke during the monitoring period were available for 344 of 348 subjects. Mean PAH concentrations ranged from 0.06 ng/m3 for dibenz[a,h]anthracene to 4.1 ng/m3 for pyrene; mean benzo[a]pyrene concentration was 0.50 ng/m3. As found in previous studies, concentrations of most PAHs were higher in winter than in summer. Multiple linear regression analysis revealed associations between personal PAH exposures and several questionnaire variables, including time spent outdoors, residential heating, and indoor burning of incense. This is the largest study to date characterizing personal exposures to PAHs, a ubiquitous class of carcinogenic air contaminants in urban environments, and is unique in its focus on pregnant minority women. PMID:15121521

Tonne, Cathryn C; Whyatt, Robin M; Camann, David E; Perera, Frederica P; Kinney, Patrick L

2004-01-01

213

Analysis of intervention strategies for inhalation exposure to polycyclic aromatic hydrocarbons and associated lung cancer risk based on a Monte Carlo population exposure assessment model.  

PubMed

It is difficult to evaluate and compare interventions for reducing exposure to air pollutants, including polycyclic aromatic hydrocarbons (PAHs), a widely found air pollutant in both indoor and outdoor air. This study presents the first application of the Monte Carlo population exposure assessment model to quantify the effects of different intervention strategies on inhalation exposure to PAHs and the associated lung cancer risk. The method was applied to the population in Beijing, China, in the year 2006. Several intervention strategies were designed and studied, including atmospheric cleaning, smoking prohibition indoors, use of clean fuel for cooking, enhancing ventilation while cooking and use of indoor cleaners. Their performances were quantified by population attributable fraction (PAF) and potential impact fraction (PIF) of lung cancer risk, and the changes in indoor PAH concentrations and annual inhalation doses were also calculated and compared. The results showed that atmospheric cleaning and use of indoor cleaners were the two most effective interventions. The sensitivity analysis showed that several input parameters had major influence on the modeled PAH inhalation exposure and the rankings of different interventions. The ranking was reasonably robust for the remaining majority of parameters. The method itself can be extended to other pollutants and in different places. It enables the quantitative comparison of different intervention strategies and would benefit intervention design and relevant policy making. PMID:24416436

Zhou, Bin; Zhao, Bin

2014-01-01

214

Risk assessment of inhalation exposure to Particulate Polycyclic Aromatic Hydrocarbons in school children  

NASA Astrophysics Data System (ADS)

Polycyclic aromatic hydrocarbons (PAHs) associated with the inhalable fraction of particulate matter were determined for one year (2009-10) at an urban site located in proximity of industrial and heavy traffic roads in Delhi, India. PM10 (aerodynamic diameter ?10 ?m) levels were ~11.6 times the World Health Organization standard. Vehicular (59.5%) and coal combustion (40.5%) sources accounted for the high levels of PAHs (range 38.1 ng m-3 - 217.3 ng m-3) with four and five ring PAHs having ~80 % contribution. Atmospheric distribution of total PAHs were heavily influenced (~75%) by the carcinogenic species and the B[a]P equivalent concentrations, through both TEF and MEF approach, exhibited highest exposure risks during winter. Extremely high daily inhalation exposure of PAHs was observed during winter (439.43 ng day-1) followed by monsoon (232.59 ng day-1) and summer (171.08 ng day-1). Daily inhalation exposure of PAHs to school children during a day exhibited the trend: school hours>commuting to school>resting period, in all the seasons. Vehicular source contributions to daily PAH levels were significantly correlated (r=0.94, p<0.001) with the daily inhalation exposure level of school children. It is important to note that health hazards posed by vehicular pollution are born disproportionately by children attending certain schools based on the location of the school. Interestingly, since India is a tropical country, most of the buildings are naturally ventilated and their air exchange rates are higher than heating, ventilation, and air conditioning (HVAC)-equipped buildings, resulting into a significant impact of outdoor air on indoor air quality. In the apparent absence of any indoor PAH sources, outdoor concentrations and in turn air exchange rates (that are specific for infiltration and natural ventilation pathways) play a key role in assessing PAH exposure. A conservative estimate of ~11 excess cancer cases in children during childhood and ~ 652 cases for a lifetime inhalation exposure of PAHs at the observed concentration have been calculated in Delhi.

Jyethi, D. S.; Khillare, P. S.; Sarkar, S.

2013-12-01

215

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

216

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

217

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

218

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...

219

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

220

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

221

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

222

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

223

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

224

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

225

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

226

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

227

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

228

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 ...

229

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

230

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

231

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

232

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

233

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

234

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

235

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

236

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

237

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...

238

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

239

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

240

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 ...

241

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 ...

242

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...

243

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...

244

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

245

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...

246

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

247

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

248

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

249

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

250

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

251

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

252

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

253

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

254

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.

255

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

256

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

257

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

258

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...

259

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 ...

260

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

261

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 ...

262

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.

263

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

264

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

265

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...

266

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

267

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 ...

268

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 (...

269

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...

270

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

271

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

272

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

273

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

274

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

275

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

276

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

277

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.

278

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

279

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

280

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

281

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

282

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.

283

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

284

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

285

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

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

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...

288

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

289

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

290

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

291

Phase and size distributions of polycyclic aromatic hydrocarbons in environmental tobacco smoke  

SciTech Connect

Phase and size distributions of polycyclic aromatic hydrocarbons (PAH) influence lung dosimetry for environmental tobacco smoke (ETS). Gas-phase components of ETS, especially water-soluble species, deposit more efficiently than particles, but they deposit in the upper airways of the human respiratory system where they can be cleared quickly. Typical ETS particles of 0.1 to 0.5 {mu}m diameter are not deposited as efficiently as gases, but they penetrate deeply into the lung and are cleared more slowly than water-soluble gas-phase components. Although the dosimetry of organic compounds in the particulate phase depends on their particle-size distribution, very little data is available for specific chemical classes such as PAH in ETS. Even less is known about the dynamic behavior of the size distribution of PAH in ETS as the smoke is diluted and aged in indoor environments. Previous studies suggest that evaporation of compounds with high volatility will dry out sidestream cigarette smoke as it is diluted into a room, and this effect will decrease the PAH concentration in smaller particles more than the bigger particles. Larger particles may also accumulate PAH by condensation of species with higher boiling points. Two new tools have been developed recently to measure the phase and size distributions of PAH, and they have been used here to investigate the dynamic behavior of simulated ETS at two temperatures (18.3 and 25.1 {degrees}C). Phase distributions of PAH have been measured in simulated ETS (diluted sidestream smoke) using the new annular denuder-based Integrated Organic Vapor-Particle sampler (IOVPS). Simultaneously, the size distributions of particulate PAH have been determined with a new microslot impactor, the Size-Segregated Environmental Tobacco Smoke Sampler (SSETS) that has cutpoints at 0.10, 0.38, 0.48, 1.7 and 3.5 {mu}m. The IOVPS and SSETS operated in an environmental chamber (20 m{sup 3}) to sample PAH over two 45-min intervals.

Gundel, L.A.; Daisey, J.M. [Lawrence Berkeley Lab., CA (United States); Hering, S.V. [Aerosol Dynamics, Inc., Berkeley, CA (United States)

1995-12-31

292

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

293

[Reference values for indoor air: dearomatized hydrocarbon solvents (C(9)-C(14))].  

PubMed

To protect public health the German Joint Working Group on Indoor Guidelines of the Federal Environmental Protection Agency and the States' Departments of Health is issuing indoor air guideline values based on a fixed procedure published in 1996. Regarding dearomatized hydrocarbon solvents/white spirits (DAWS--CAS-No. 64742-47-8, 64742-48-9, 64742-88-7, 64741- 65-7) no human data are available. From animal studies, neurotoxicity, developmental toxicity and reproductive toxicity were identified as critical endpoints. For risk evaluation the Hass et al. (2001) study was used as the pivotal study. Based on effects at 4680 mg DAWS/m(3) for the endpoint developmental toxicity, the lowest adverse effect level for chronic exposure is assessed as 400 mg DAWS/m(3). By applying an interspecies factor of 10, an intraspecies factor of 10 and an additional factor 2 referring to the special physiology of children (higher breath rate compared to adults) a so-called health hazard value of 2 mg DAWS/m(3) indoor air and a so-called health prevention value of 0.2 mg DAWS/m(3) are obtained. PMID:16003576

Sagunski, H; Mangelsdorf, I

2005-07-01

294

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

295

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

296

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

297

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...

298

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...

299

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

300

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...

301

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...

302

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...

303

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...

304

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

305

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...

306

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...

307

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...

308

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

309

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

310

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

311

[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

312

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

313

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

314

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

315

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

316

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

317

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

318

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

319

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

320

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

321

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

322

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

323

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

324

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

325

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

326

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

327

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

328

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

329

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

330

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

331

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

332

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

333

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

334

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

335

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

336

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

337

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

338

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

339

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

340

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

341

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

342

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

343

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

344

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

345

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

346

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

347

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

348

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

349

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

350

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

351

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

352

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

353

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

354

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

355

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

356

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

357

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

358

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

359

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

360

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

361

[Study on degradation of polycyclic aromatic hydrocarbons (PAHs) with different additional carbon sources in aged contaminated soil].  

PubMed

This study was conducted with different additional carbon sources (such as: glucose, DL-malic acid, citrate, urea and ammonium acetate) to elucidate the degradation of polycyclic aromatic hydrocarbons (PAHs) in aged contaminated soil under an indoor simulation experiment. The results showed that the quantity of CO2 emission in different additional carbon sources treatments was obviously much more than that of check treatment in the first week, and the quantity of CO2 emission in DL-malic acid treatment was the largest. The average CO2 production decreased in an order urea > glucose approximately citrate approximately DL-malic acid approximately ammonium acetate > check. Meanwhile, the amount of volatized PAHs in applied carbon sources treatments was significantly less than that in check treatment. The amount of three volatized PAHs decreased in an order phenanthrene > fluoranthene > benzo(b)fluoranthene. Compared with the check treatment, the average degradation rates of the three PAHs were significantly augmented in the supplied carbon sources treatments, in which rates of the three PAHs were much higher in DL-malic acid and urea treatments than those in other treatments. The largest proportion of residual was benzo(b)fluoranthene (from 72% to 81%) among three PAHs compounds, followed by fluoranthene (from 53% to 70% ) and phenanthrene (from 27% to 44%). PMID:22509608

Yin, Chun-Qin; Jiang, Xin; Wang, Fang; Wang, Cong-Ying

2012-02-01

362

Evaluation of field methods for estimating exposure of children in low-income families to polycyclic aromatic hydrocarbons  

SciTech Connect

Children in low-income families may have higher exposures to polycyclic aromatic hydrocarbons (PAH) and related compounds than children in higher-income families. These higher exposures could result from the location of their homes, nearer to industrial sites and traffic; from poorer diet; from environmental tobacco smoke; or other causes. The study was designed to evaluate methods and estimate the range of total exposures of low-income children to PAH through various pathways. Nonsmoking participants with preschool children, incomes at or below the official US poverty level, and space heating in their homes were recruited. The PAH concentrations were measured in the household indoor and outdoor air, house dust, and yard soil, and in the diet of both an adult and a preschool child living in the home. An initial study in two homes and an additional study of nine homes, four urban and five rural, during the heating season were completed. The problems and successes encountered in the recruitment process and selected results of the heating season measurements are summarized in the paper.

Wilson, N.K.; Chuang, J.C.; Lyu, C.

1996-12-31

363

Polycyclic aromatic hydrocarbons in deposited bedroom dust collected from Xinxiang, a fast developing city in North China.  

PubMed

To investigate the contamination levels of polycyclic aromatic hydrocarbons (PAHs) in the indoor environment, 16 PAHs were measured in 20 deposited bedroom dust (DBD) samples collected from four residential areas in Xinxiang City. The total PAH concentrations (?PAHs, defined as the sum of 16 PAHs) in 20 DBD samples ranged from 1.47 to 21.8 ?g/g dry weight. PAH ratios indicated that main sources of PAHs in most DBD samples were coal, grasses, and wood combustion. Correlation analysis showed that there were no significant positive correlations between ?PAH concentrations in DBD and the number of family members or duration of residence. Analysis using the t test revealed that tobacco smoke was a source of PAHs in DBD and that an unattached kitchen may be a significant influencing factor related to PAHs in DBD collected from residential areas in Xinxiang City. Our results showed that the kitchen exhaust fan or hood had no significant influence on total PAHs in DBD, and there was no significant difference in ?PAH concentrations in DBD in homes which used liquefied petroleum gas and those which used natural gas. PMID:25404542

Yang, Zhong-Zhi; Li, Yong-Fang; Fan, Jing

2015-01-01

364

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

365

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

366

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

367

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

368

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

369

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

370

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

371

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

372

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

373

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

374

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

375

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

376

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

377

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

378

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

379

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

380

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

381

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

382

[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

383

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

384

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

385

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

386

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

387

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

388

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

389

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

390

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

391

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

392

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

393

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

394

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

395

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

396

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

397

FIELD EVALUATION OF SAMPLING AND ANALYSIS FOR ORGANIC POLLUTANTS IN INDOOR AIR  

EPA Science Inventory

The objectives of the study were to determine the feasibility of the use of newly developed indoor air samplers in residential indoor air sampling and to evaluate methodology for characterization of the concentrations of polynuclear aromatic hydrocarbons (PAH), PAH derivatives, a...

398

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

399

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

400

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

401

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

402

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

403

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

404

Children and elders exposure assessment to particle-bound polycyclic aromatic hydrocarbons (PAHs) in the city of Rome, Italy.  

PubMed

It has been amply demonstrated that exposure to fine particulate matter, containing polycyclic aromatic hydrocarbons (PAHs), may have adverse effects on human health, affecting especially the respiratory and cardiovascular systems. Among population, school-age children and elders present particular susceptibilities and unique exposures to environmental factors. The study presented in this paper belongs to the Project EXPAH, founded by the European (EU) LIFE+ instrument, and consists of the personal monitoring of five elementary school children and four elders during the spring and the summer/autumn of the year 2012 in the city of Rome, Italy. The average exposure, expressed as the sum of eight high-molecular-weight PAHs, resulted equal to 0.70 ng/m(3) (SD?=?0.37) for children and 0.59 ng/m(3) (SD?=?0.23) for the elderly people. The mean levels of gravimetric PM2.5 were equal to 23 ?g/m(3) (SD?=?10) and 15 ?g/m(3) (SD?=?4) for children and elders, respectively. During spring and summer seasons, personal BaPeq resulted well below the EU Air Quality reference value of 1 ng/m(3). The personal monitoring average values were in the same order of magnitude with available indoor and outdoor environmental data in Rome during the same periods, for both PAHs and PM2.5. The results suggest that, during non-heating seasons, the personal exposure to PAHs in the city of Rome can be mainly ascribed to the urban background, especially traffic emissions and road dust resuspension; secondhand cigarette smoke can be also considered another possible source of PAHs personal exposure. PMID:24374616

Gatto, Maria Pia; Gariazzo, Claudio; Gordiani, Andrea; L'Episcopo, Nunziata; Gherardi, Monica

2014-12-01

405

Urinary polycyclic aromatic hydrocarbons as a biomarker of exposure to PAHs in air: a pilot study among pregnant women.  

PubMed

Recent studies have linked increased polycyclic aromatic hydrocarbons (PAHs) in air and adverse fetal health outcomes. Urinary PAH metabolites are of interest for exposure assessment if they can predict PAHs in air. We investigated exposure to PAHs by collecting air and urine samples among pregnant women pre-selected as living in "high" (downtown and close to steel mills, n=9) and "low" (suburban, n=10) exposure areas. We analyzed first-morning urine voids from all 3 trimesters of pregnancy for urinary PAH metabolites and compared these to personal air PAH/PM(2.5)/NO(2)/NO(X) samples collected in the 3rd trimester. We also evaluated activities and home characteristics, geographic indicators and outdoor central site PM(2.5)/NO(2)/NO(X) (all trimesters). Personal air exposures to the lighter molecular weight (MW) PAHs were linked to indoor sources (candles and incense), whereas the heavier PAHs were related to outdoor sources. Geometric means of all personal air measurements were higher in the "high" exposure group. We suggest that centrally monitored heavier MW PAHs could be used to predict personal exposures for heavier PAHs only. Urine metabolites were only directly correlated with their parent air PAHs for phenanthrene (Pearson's r=0.31-0.45) and fluorene (r=0.37-0.58). Predictive models suggest that specific metabolites (3-hydroyxyfluorene and 3-hydroxyphenanthrene) may be related to their parent air PAH exposures. The metabolite 2-hydroxynaphthalene was linked to smoking and the metabolite 1-hydroxypyrene was linked to dietary exposures. For researchers interested in predicting exposure to airborne lighter MW PAHs using urinary PAH metabolites, we propose that hydroxyfluorene and hydroxyphenanthrene metabolites be considered. PMID:21915154

Nethery, Elizabeth; Wheeler, Amanda J; Fisher, Mandy; Sjödin, Andreas; Li, Zheng; Romanoff, Lovisa C; Foster, Warren; Arbuckle, Tye E

2012-01-01

406

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

407

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

408

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

409

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

410

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

411

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

412

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

413

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

414

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

415

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

416

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

417

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

418

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

419

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

420

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

421

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

422

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

423

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

424

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...

425

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

426

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

427

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

428

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

429

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...

430

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...

431

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

432

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.

433

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

434

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

435

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

436

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

437

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; Auratai Aramphongphan; Herman Autrup

2002-01-01

438

Thyroid hormone binding proteins as novel targets for hydroxylated polyhalogenated aromatic hydrocarbons (PHAHs): possible implications for toxicity  

Microsoft Academic Search

Some toxic effects caused by polyhalogenated aromatic hydrocarbons (PHAHs) develop through alterations in the reproductive and thyroid hormone regulatory systems, thereby affecting (brain) development, reproduction and behaviour of several species (Stone, 1995, Birnbaum, 1994, for review: Brouwer et al. , 1995, Peterson et al. , 1993). In this thesis we have focused on the effects of different classes of PHAHs,

M. C. Lans

1995-01-01

439

Increased Polycyclic Aromatic Hydrocarbon Toxicity Following Their Photomodification in Natural Sunlight: Impacts on the Duckweed Lemna gibba L. G-3  

Microsoft Academic Search

The authors previously demonstrated that simulated solar radiation (SSR), with a fluence rate of only 40 ?mol m?2 sec?1 increased polycyclic aromatic hydrocarbon (PAH) toxicity to the duckweed Lemna gibba and that PAHs photomodified in SSR (generally oxygenation of the ring system) are more toxic than the parent compounds (Huang et al., Environ. Toxicol. Chem, 1993, 12, 1067-1077). It is

X. D. Huang; D. G. Dixon; B. M. Greenberg

1995-01-01

440

Genome Sequence of Martelella sp. Strain AD-3, a Moderately Halophilic Polycyclic Aromatic Hydrocarbon-Degrading Bacterium  

PubMed Central

Martelella sp. strain AD-3, enriched from a petroleum-contaminated site with high salinity, can efficiently degrade polycyclic aromatic hydrocarbons. Here, we report the 4.75-Mb genome sequence of strain AD-3 with its genetic feature of helping to remediate environmental organic pollutants. PMID:24435873

Cui, Changzheng; Li, Pengpeng; Liu, Gao; Lin, Kuangfei; Luo, Qishi; Liu, Shanshan; Xu, Ping

2014-01-01

441

Draft Genome Sequence of Halotolerant Polycyclic Aromatic Hydrocarbon-Degrading Pseudomonas bauzanensis Strain W13Z2.  

PubMed

Pseudomonas bauzanensis W13Z2 is a halotolerant polycyclic aromatic hydrocarbon (PAH)-degrading bacterium isolated from petroleum-contaminated drill cuttings in the Bohai Sea. Here, we report the 8.6-Mb draft genome sequence of this strain, which will provide insights into the diversity of Pseudomonas and the mechanism of PAHs degradation in drill cuttings. PMID:25323719

Wang, Xinxin; Jin, Decai; Zhou, Lisha; Wu, Liang; Qi, Lin; Li, Chen; An, Wei; Chen, Yu

2014-01-01

442

MONITORING THE SUCCESS OF SEDIMENT REMEDIATION AT A SITE CONTAMINATED WITH CHLORINATED PESTICIDES, POLYNUCLEAR AROMATIC HYDROCARBONS AND ARSENIC  

EPA Science Inventory

Monitoring the Success of Sediment Remediation at a Site Contaminated with Chlorinated Pesticides, Polynuclear Aromatic Hydrocarbons and Arsenic (Baird & McGuire Superfund Site, Holbrook, MA) Contaminated sediment in the Cochato River adjacent to the Baird & McGuire Superfund Sit...

443

THE PENALIZED OPTIMAL EXPERIMENTAL DESIGN: THE PRECISE ESTIMATION OF AN INTERACTION THRESHOLD IN A MIXTURE OF EIGHTEEN POLYHALOGENATED AROMATIC HYDROCARBONS.  

EPA Science Inventory

Crofton et al. (EHP, 2005) conducted a study of 18 polyhalogenated aromatic hydrocarbons (PHAHs) on serum total thyroxine (T4). Young female Long-Evans rats were dosed with the 18 single agents or a fixed-ratio mixture, and serum total T4 was measured via radioimmunoassay. The i...

444

Ligand Activation of the Aromatic Hydrocarbon Receptor Transcription Factor Drives Bax-Dependent Apoptosis in Developing Fetal Ovarian Germ Cells  

Microsoft Academic Search

We recently reported that a targeted disruption of the gene encoding the aromatic hydrocarbon receptor (AHR) in mice reduces fetal oocyte apoptosis, leading to a 2-fold increase in the number of primordial follicles endowed at birth. Although the identity of the natural ligand(s) for the AHR remains to be unequivocally established, these findings indicate that the level of AHR function

TIINA M. MATIKAINEN; TOSHITAKE MORIYAMA; YUTAKA MORITA; GLORIA I. PEREZ; STANLEY J. KORSMEYER; DAVID H. SHERR; JONATHAN L. TILLY

2002-01-01

445

Application of Radiocarbon Analysis and Receptor Modeling to the Source Apportionment of Pahs (polycyclic Aromatic Hydrocarbons) in the Atmosphere  

Microsoft Academic Search

The radiocarbon tracer technique was used to demonstrate that polycyclic aromatic hydrocarbons (PAHs) can be used for quantitative receptor modeling of air pollution. Fine -particle samples were collected during December, 1985, in Albuquerque, NM. Motor vehicles (fossil) and residential wood combustion (\\

Ann Elizabeth Sheffield

1988-01-01

446

Cumulative Exposure Assessment for Trace-Level Polycyclic Aromatic Hydrocarbons (PAHs) using Human Blood and Plasma Analysis  

EPA Science Inventory

Humans experience chronic cumulative trace-level exposure to mixtures of volatile, semi-volatile, and non-volatile polycyclic aromatic hydrocarbons (PAHs) present in the environment as by-products of combustion processes. Certain PAHs are known or suspected human carcinogens and ...

447

Studies on the dissolution of polycyclic aromatic hydrocarbons from contaminated materials using a novel dialysis tubing experimental method  

Microsoft Academic Search

Assessment of risk and remediation strategies at contaminated sites requires that both the amounts of contaminants present and their potential for release from materials and soils be evaluated. The release, or dissolution, of polycyclic aromatic hydrocarbons (PAHs) from contaminated materials to water was therefore investigated. To facilitate investigations of PAH dissolution from physically disparate materials such as solid coal tars,

Paula J. Woolgar; Kevin C. Jones

1999-01-01

448

Bioremediation of an aged polycyclic aromatic hydrocarbons (PAHs)-contaminated soil by filamentous fungi isolated from the soil  

Microsoft Academic Search

Twenty-one filamentous fungi were isolated from the soil of an old polycyclic aromatic hydrocarbon (PAH)-contaminated gaswork site and tested in their native soil for PAH degradation. This degradation study was performed for each isolate with two inoculation treatments, by spore or mycelial inoculum. An improvement in the extent of total PAH degradation occurred with mycelial inoculum. The greatest degradation was

Olivier Potin; Catherine Rafin; Etienne Veignie

2004-01-01

449

Influence of the carbon\\/nitrogen\\/phosphorus ratio on polycyclic aromatic hydrocarbon degradation by Mycobacterium and Sphingomonas in soil  

Microsoft Academic Search

Biodegradation of polycyclic aromatic hydrocarbons (PAHs) in the environment is often limited due to unfavorable nutrient conditions for the bacteria that use these PAHs as sole source of carbon and energy. Mycobacterium and Sphingomonas are 2 PAH-degrading specialists commonly present in PAH-polluted soil, but not much is known about their specific nutrient requirements. By adding different inorganic supplements of nitrogen

Natalie M. Leys; Leen Bastiaens; Willy Verstraete; Dirk Springael

2005-01-01

450

Comparison of Plant Families in a Greenhouse Phytoremediation Study on an Aged Polycyclic Aromatic Hydrocarbon–Contaminated Soil  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous, recalcitrant, and potentially carcinogenic pollutants. Plants and their associated rhizosphere microbes can promote PAH dissipation, off ering an economic and ecologically attractive remediation technique. Th is study focused on the eff ects of diff erent types of vegetation on PAH removal and on the interaction between the plants and their associated microorganisms. Aged PAH-polluted

Paul E. Olson; Ana Castro; Mark Joern; Nancy M. DuTeau; Elizabeth A. H. Pilon-Smits; Kenneth F. Reardon

2007-01-01

451

Detection of Microbial Growth on Polycyclic Aromatic Hydrocarbons in Microtiter Plates by Using the Respiration Indicator WST1  

Microsoft Academic Search

We have developed a microtiter plate method for screening a large number of bacterial isolates for the ability to grow on different crystalline polycyclic aromatic hydrocarbons (PAHs). Growth on PAHs cannot easily be determined with standard growth assays because of the very low aqueous solubility and bioavailability of the PAHs. Our microtiter plate assay utilizes a new water-soluble respiration indicator,

Anders R. Johnsen; Karen Bendixen; Ulrich Karlson

2002-01-01

452

FISH BILIARY POLYCYCLIC AROMATIC HYDROCARBON METABOLITES ESTIMATED BY FIXED-WAVELENGTH FLUORESCENCE: COMPARISON WITH HPLC-FLUORESCENT DETECTION  

EPA Science Inventory

Fixed wavelength fluorescence (FF) was compared to high-performance liquid chromatography with fluorescence detection (HPLC-F) as an estimation of polycyclic aromatic hydrocarbon (PAH) exposure to fish. Two excitation/emission wavelength pairs were used to measure naphthalene- an...

453

Trace elements, organochlorines, polycyclic aromatic hydrocarbons, dioxins, and furans in lesser scaup wintering on the Indiana Harbor Canal  

Microsoft Academic Search

During the winter of 1993–94, male lesser scaup (Aythya affinis) were collected on the heavily polluted Indiana Harbor Canal (IHC), East Chicago, IN, USA, and examined for tissue contaminant levels. Lesser scaup collected on the IHC had higher concentrations of cadmium (Cd), mercury (Hg), selenium (Se), polychlorinated biphenyls (PCBs), selected organchlorine pesticides, polychlorinated dibenzodioxins, polychlorinated dibenzofurans, polycyclic aromatic hydrocarbons, and

T. W. Custer; C. M. Custer; R. K. Hines; D. W. Sparks

2000-01-01

454

Determination of Firefighter Exposure to Polycyclic Aromatic Hydrocarbons and Benzene During Fire Fighting Using Measurement of Biological Indicators  

Microsoft Academic Search

In accomplishing their duties, firefighters are potentially exposed to a vast array of toxic combustion and pyrolysis products such as benzene, carbon monoxide, acrolein, nitrogen dioxide, and polycyclic aromatic hydrocarbons. Exposure to PAH and benzene was assessed by means of urinary measurements of 1-hydroxypyrene and t,t -muconic acid, respectively. All urine samples were collected from 43 firefighters during a period

Chantal Caux; Cindy OBrien; Claude Viau

2002-01-01

455

Draft Genome Sequence of Halotolerant Polycyclic Aromatic Hydrocarbon-Degrading Pseudomonas bauzanensis Strain W13Z2  

PubMed Central

Pseudomonas bauzanensis W13Z2 is a halotolerant polycyclic aromatic hydrocarbon (PAH)-degrading bacterium isolated from petroleum-contaminated drill cuttings in the Bohai Sea. Here, we report the 8.6-Mb draft genome sequence of this strain, which will provide insights into the diversity of Pseudomonas and the mechanism of PAHs degradation in drill cuttings. PMID:25323719

Jin, Decai; Zhou, Lisha; Wu, Liang; Qi, Lin; Li, Chen; An, Wei; Chen, Yu

2014-01-01

456

Organocatalytic C–H/C–H' cross-biaryl coupling: C-selective arylation of sulfonanilides with aromatic hydrocarbons.  

PubMed

The hypervalent iodine-mediated C-C selective coupling of N-methanesulfonyl anilides with aromatic hydrocarbons has been developed. The first organocatalytic oxidative cross-biaryl-coupling was achieved by the catalyst control in defining specific 2,2'-diiodobiphenyls for the direct C-C bond formations. PMID:24028674

Ito, Motoki; Kubo, Hiroko; Itani, Itsuki; Morimoto, Koji; Dohi, Toshifumi; Kita, Yasuyuki

2013-09-25

457

Towards a Solution of the Polycyclic Aromatic Hydrocarbon - Diffuse Interstellar Band Hypothesis  

E-print Network

A novel theoretical method is developed to study the polycyclic aromatic hydrocarbon - diffuse interstellar band (PAH-DIB) hypothesis. In this method, a computer program is used to enumerate all PAH molecules with up to a specific number of fused benzene rings. Fast quantum chemical calculations are then employed to calculate the electronic transition energies, oscillator strengths, and rotational constants of these molecules. An electronic database of all PAHs with up to any specific number of benzene rings can be constructed this way. Comparison of the electronic transition energies, oscillator strengths, and rotational band contours of all PAHs in the database with astronomical spectra allows one to identify possible individual PAH carriers of some of the intense narrow DIBs. Using the current database containing up to 10 benzene rings we have selected 8 closed-shell PAHs as possible carriers of the intense lambda6614 DIB.

Xiaofeng Tan

2006-08-31

458

Variations of polychlorinated biphenyls and polycyclic aromatic hydrocarbons in southern Lake Michigan surface waters  

SciTech Connect

Surface water samples were collected near Chicago to determine if atmospheric contaminants in urban areas result in elevated water column concentrations. Samples taken in time series reveal seasonal variations in partitioning and surface water concentrations. Southwest winds passing over the Chicago metropolitan area caused an increase in surface water polychlorinated biphenyl (PCB) concentrations in near shore southern Lake Michigan. Furthermore, surface water PCB concentrations varied seasonally with higher concentrations during winter. Southwest winds passing over the Chicago metropolitan area did not cause an appreciable increase in surface water concentrations of polycyclic aromatic hydrocarbons (PAHs) in near shore Southern Lake Michigan surface waters. Only particle bound PAH concentrations varied seasonally with higher suspended particulate concentrations accounting for most of the increase.

Offenberg, J.H.; Baker, J.E. [Univ. of Maryland, Solomons, MD (United States); [Univ. of Maryland, College Park, MD (United States). Dept. of Chemistry and Biochemistry

1995-12-31

459

Uncertainty estimation related to analysis of volatile aromatic hydrocarbons by static headspace gas chromatography.  

PubMed

A study of the analysis of benzene, toluene, ethylbenzene and xylenes by static headspace gas chromatography illustrated the estimation of uncertainty associated with the influence of several parameters, such as preparation of the standard solutions, calibration of the instrument, recovery and limit of detection. The objective of the investigation was to indicate the contribution of each stage in the developed procedure on the uncertainty measurement of the determination of volatile aromatic hydrocarbons in surface and underground water. The uncertainty sources were identified and illustrated in an effect diagram. The data illustrated the evaluation of uncertainty by the quantification of the uncertainty arising separately from each source. It has been demonstrated that data can be used to estimate the uncertainty resulting from the combined effect of all sources. PMID:23885042

Pavlova, Antoaneta; Stoyanova, Olga; Ivanova, Pavlina; Dimova, Teodora

2014-08-01

460

[Experimental research on alcohols, aldehydes, aromatic hydrocarbons and olefins emissions from alcohols fuelled vehicles].  

PubMed

Using two vehicles fuelled with pure gasoline, M15, M30 and pure gasoline, E10, E20 separately, 25 degrees C normal temperature type I emission test, -7 degrees C low temperature type VI emission test and type IV evaporation emission test were carried out. FTIR, HPLC and GC-MS methods were utilized to measure alcohols, aldehydes, aromatic hydrocarbons and olefins emissions. The test results indicate that at the low as well as normal ambient temperature, as the alcohols proportion increasing in the fuel, unburned methanol, formaldehyde, acetaldehyde increase proportionally, benzene, toluene, ethylene, propylene, 1,3-butadiene and isobutene decrease slightly. The unregulated emissions at the low ambient temperature are significantly higher than those at the normal ambient temperature. The difference of HC emissions in the entire process of evaporative emission tests of E10, gasoline and M15 fuels is slight. There is a small difference of unregulated emissions in the diurnal test of three fuels. PMID:24027980

Zhang, Fan; Wang, Jian-Hai; Wang, Xiao-Cheng; Wang, Jian-Xin

2013-07-01

461

Cost of Developmental Delay from Prenatal Exposure to Airborne Polycyclic Aromatic Hydrocarbons  

PubMed Central

Early life exposure to ambient polycyclic aromatic hydrocarbons (PAHs) can result in developmental delay. The negative health effects of PAHs have been well-documented but the cost of developmental delay due to PAH exposure has not been studied. The Columbia Center for Children’s Environmental Health previously has reported the significant effect of prenatal exposure to ambient PAHs on delayed mental development at three years, using the Bayley Scales in a cohort of low-income women and children in New York City (NYC). Here we have used the cohort results to estimate the annual costs of preschool special education services for low-income NYC children with developmental delay due to PAH exposure using the Environmentally Attributable Fraction method. The estimated cost of PAH-exposure-related services is over $13.7 million per year for Medicaid births in NYC. This high cost supports policies to reduce level of PAHs in NYC air. PMID:21317525

Weiland, Katherine; Neidell, Matthew; Rauh, Virginia; Perera, Frederica

2013-01-01

462

Biological risk and pollution history of polycyclic aromatic hydrocarbons (PAHs) in Nansha mangrove, South China.  

PubMed

Chinese government has taken various measures to alleviate pollution caused by polycyclic aromatic hydrocarbons (PAHs) in the region of Pearl River Delta since the economic reform in 1978, but the effectiveness of these measures remains largely unknown. This study aimed to elucidate the biological risk and pollution history of PAHs by measuring the concentrations of 28 PAHs in the surface and core sediments, respectively, in Nansha mangrove. Results found that the biological risk of PAHs was low without obvious spatial variation. The PAH concentration along the depth gradient indicated that PAH pollution was stabilized since the early 1990s while the source of PAHs has gradually changed from combustion of coal to petroleum products. This implied that the mitigation measures taken by the Chinese government were effective. Compared to marine bottom sediment, we propose that using mangrove sediment can provide a more accurate and precise estimate of pollution history of PAHs. PMID:24981104

Wu, Qihang; Leung, Jonathan Y S; Tam, Nora F Y; Chen, Shejun; Mai, Bixian; Zhou, Xizhen; Xia, Lihua; Geng, Xinhua

2014-08-15

463

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 P