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1

Concentrations and sources of polycyclic aromatic hydrocarbons in indoor dust in China.  

PubMed

Indoor dust samples were collected across China in the winter of 2010 from 45 private domiciles and 36 public buildings. 16 polycyclic aromatic hydrocarbons (PAHs) were determined by GC-MS. Total concentrations of PAHs ranged from 1.00 ?g/g to 470 ?g/g with a mean value of 30.9 ?g/g. High-molecular weight (HMW) PAHs (4 to 6 rings) are the predominant PAHs found in indoor dust, accounting for 68% of the total PAH concentration in private domiciles, and 84.6% in public buildings. Traffic conditions and cooking methods were the two key factors controlling PAH levels, especially for coal combustion and vehicular traffic emission sources. A significant positive correlation was observed between PAH concentrations in indoor dust and based on location (latitude and longitude). The latitudinal distribution indicated a higher usage of coal for heating in Northern China than in Southern China. The longitudinal distribution indicated that the usage of oil and mineral fuels as well as economic development and population density increased from West China to East China. In addition, diagnostic ratios and principal component analysis (PCA) were used to explore source apportion, as indicated in both the pyrogenic and petrogenic sources of PAHs in indoor dust in China. Furthermore, the BaP equivalent was applied to assess the carcinogenic risk of PAHs, which also indicated that traffic emissions and coal combustion were the two major contributions to carcinogenic risk of PAHs in indoor dust in China. PMID:24602396

Qi, Hong; Li, Wen-Long; Zhu, Ning-Zheng; Ma, Wan-Li; Liu, Li-Yan; Zhang, Feng; Li, Yi-Fan

2014-09-01

2

Monitoring of indoor volatile organic compounds and polycyclic aromatic hydrocarbons arising from kerosene cooking fuel.  

PubMed

Air samples, representing indoor environments of a kitchen in which a kerosene stove was used were collected and analysed for volatile organic compounds (VOCs) viz., n-hexane, benzene, heptane, toluene, p- and o-xylene and n-decane using a cryogenic preconcentration system and a gas chromatograph with a flame-ionisation detector. Simultaneous outdoor samples were also collected to determine indoor to outdoor (I/O) ratios for each compound. Reversed phase high performance liquid chromatography (HPLC) with ultra violet absorption detection was optimised for separation and quantification of polycyclic aromatic hydrocarbons (PAHs) in air particulate matter. Concentration of total suspended particulate matter (TSPM), benzene soluble organics and the PAHs in air samples collected in indoor environment of some tenements at Trombay, Mumbai where kerosene is used as cooking fuel are discussed in relation to the concentration of the same in outdoor environment in vicinity of the tenement. VOCs and PAHs results from samples collected in kitchens in Trombay are discussed in relation to indoor air pollution. PMID:11712593

Pandit, G G; Srivastava, P K; Rao, A M

2001-11-12

3

IDENTIFICATION AND QUANTIFICATION OF NITROPOLYNUCLEAR AROMATIC HYDROCARBONS IN AMBIENT AND INDOOR AIR PARTICULATE SAMPLES  

EPA Science Inventory

Polynuclear aromatic hydrocarbons (PAH) and nitro-substituted polynuclear aromatic hydrocarbons (NO2-PAH) have been identified in organic extracts of ambient air particulate matter. Many of the identified PAH and NO2-PAH are potent carcinogens and/or mutagens. Therefore the deter...

4

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.

5

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

6

Analysis of industrial contaminants in indoor air: part 1. Volatile organic compounds, carbonyl compounds, polycyclic aromatic hydrocarbons and polychlorinated biphenyls.  

PubMed

This article reviews recent literature on the analysis of industrial contaminants in indoor air in the framework of the REACH project, which is mainly intended to improve protection of human health and the environment from the risks of more than 34 millions of chemical substances. Industrial pollutants that can be found in indoor air may be of very different types and origin, belonging to the volatile organic compounds (VOCs) and semivolatile organic compounds (SVOCs) categories. Several compounds have been classified into the priority organic pollutants (POPs) class such as polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and furans (PCDD/PCDFs) and related polychlorinated compounds, and polycyclic aromatic hydrocarbons (PAHs). Many of these compounds are partially associated to the air gas phase, but also to the suspended particulate matter. Furthermore, settled dust can act as a concentrator for the less volatile pollutants and has become a matrix of great concern for indoors contamination. Main literature considered in this review are papers from the last 10 years reporting analytical developments and applications regarding VOCs, aldehydes and other carbonyls, PCBs, PCDDs, PCDFs, and PAHs in the indoor environment. Sample collection and pretreatment, analyte extraction, clean-up procedures, determination techniques, performance results, as well as compound concentrations in indoor samples, are summarized and discussed. Emergent contaminants and pesticides related to the industrial development that can be found in indoor air are reviewed in a second part in this volume. PMID:19019381

Barro, Ruth; Regueiro, Jorge; Llompart, María; Garcia-Jares, Carmen

2009-01-16

7

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 ...

8

Source Attribution of Personal Exposure to Airborne Polycyclic Aromatic Hydrocarbon Mixture Using Concurrent Personal, Indoor, and Outdoor Measurements  

PubMed Central

Objectives Relative importance of multiple indoor and outdoor venues on personal exposure concentrations to pro-carcinogenic polycyclic aromatic hydrocarbons (c-PAHs) remains poorly understood. This is particularly challenging because many c-PAHs share sources and occur as a complex mixture. Accurate and precise apportionment of personal exposure according to exposure venues could aid in understanding of human health effects due to given source. Here, we partitioned indoor and personal exposure concentrations to seven c-PAHs and pyrene according to the indoor- and outdoor- origins. Methods A simultaneous, integrated monitoring of personal, indoor and outdoor concentrations of nine PAHs was conducted in 75 homes for a consecutive 48-hour period across a two-year period in Kraków, Poland. Due to few known indoor sources for chrysene, we used this PAH species as a tracer for infiltration of outdoor PAHs. Personal and indoor concentrations of seven c-PAHs and pyrene were apportioned to home indoor, non-home indoor and outdoor origin. Results Using Chrysenein / Chryseneout as proxy for an infiltration factor, Finf, infiltrated PAHs of outdoor origin are overall higher in concentration than those emitted from the indoor origin. Average contribution by the outdoor sources on B[a]A, B[b]F, and B[k]F were 92%, 79%, and 78% across all seasons. In contrast, in homes where a household members smoked, average contribution by the outdoor sources on B[ghi]P, B[a]P, D[ah]A, and IP were lower (i.e., 67%, 65%, 67%, and 66%, respectively). Season-averaged contribution by the outdoor sources on personal exposure to B[a]A, B[b]F, and B[k]F were 92%, 74%, and 77%, respectively. On the other hand, season-averaged home indoor source contribution on personal exposure to B[a]A, B[b]F, and B[k]F were estimated at 6%, 15%, and 19%, respectively. Similar contributions by season-averaged home indoor sources on personal exposure were estimated at 28% for B[ghi]P, 31% for B[a]P, 25% for D[ah]A, and 28% for IP. Conclusion Of the seven c-PAHs, B[a]A, B[b]F, and B[k]F are enriched in indoor and personal exposure concentrations from the outdoor coal-combustion. B[ghi]P, B[a]P, D[a,h]A, and IP, PAHs with some of the highest carcinogenic and mutagenic potencies, are considerably enriched by cigarette smoke in addition to the outdoor sources. PMID:24316321

Choi, Hyunok; Spengler, John

2014-01-01

9

Polycyclic Aromatic Hydrocarbons (PAHs) in Indoor Dusts of Guizhou, Southwest of China: Status, Sources and Potential Human Health Risk  

PubMed Central

Polycyclic aromatic hydrocarbons (PAHs) were analyzed for 136 indoor dust samples collected from Guizhou province, southwest of China. The ?18PAHs concentrations ranged from 2.18 ?g•g-1 to 14.20 ?g•g-1 with the mean value of 6.78 ?g•g-1. The highest ?18PAHs concentration was found in dust samples from orefields, followed by city, town and village. Moreover, the mean concentration of ?18PAHs in indoor dust was at least 10% higher than that of outdoors. The 4–6 rings PAHs, contributing more than 70% of ?18PAHs, were the dominant species. PAHs ratios, principal component analysis with multiple linear regression (PCA-MLR) and hierarchical clustering analysis (HCA) were applied to evaluate the possible sources. Two major origins of PAHs in indoor dust were identified as vehicle emissions and coal combustion. The mean incremental lifetime cancer risk (ILCR) due to human exposure to indoor dust PAHs in city, town, village and orefield of Guizhou province, China was 6.14×10?6, 5.00×10?6, 3.08×10?6, 6.02×10?6 for children and 5.92×10?6, 4.83×10?6, 2.97×10?6, 5.81×10?6 for adults, respectively. PMID:25719362

Li, Baizhan

2015-01-01

10

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

11

Evaluation of methods for simultaneous collection and determination of nicotine and polynuclear aromatic hydrocarbons in indoor air  

SciTech Connect

A study was performed to determine whether one sampling system and one analytical method can be used to collect and measure both polynuclear aromatic hydrocarbons (PAHs) and nicotine. PAH collection efficiencies for both XAD-2 and XAD-4 adsorbents were very similar, but nicotine collection efficiency was greater for XAD-4. Spiked perdeuterated PAHs were retained well in both adsorbents after exposure to more than 300 m{sup 3} of air. A two-step Soxhlet extraction, dichloromethane followed by ethyl acetate, was used to remove nicotine and PAHs from XAD-4. The extract was analyzed by positive chemical ionization or electron impact gas chromatography/mass spectrometry (GC/MS) to determine nicotine and PAHs. It is shown that one sampling system (quartz fiber filter and XAD-4 in series) and one analytical method (Soxhlet extraction and GC/MS) can be used for both nicotine and PAHs in indoor.

Chuang, J.C.; Kuhlman, M.R. (Battelle, Columbus, OH (USA)); Wilson, N.K. (Environmental Protection Agency, Research Triangle Park, NC (USA))

1990-05-01

12

Evaluation of methods for simultaneous collection and determination of nicotine and polynuclear aromatic hydrocarbons in indoor air  

SciTech Connect

A study was performed to determine whether one sampling system and one analytical method can be used to measure both polynuclear aromatic hydrocarbons (PAH) and nicotine. The PAH collection efficiencies for both XAD-2 and XAD-4 adsorbents are very similar, but the nicotine collection efficiency was greater for XAD-4. The spiked perdeuterated PAH were retained well in both adsorbents after exposure to more than 300 cu m of air. A two-step Soxhlet extraction, dichloromethane followed by ethylacetate, was used to remove nicotine and PAH from XAD-4. The extract was analyzed by positive chemical ionization or electron impact gas chromatography/mass spectrometry (GC/MS) to determine nicotine and PAH. It is shown that one sampling system (quartz fiber filter and XAD-4 in series) and one analytical method (Soxhlet extraction and GC/MS) can be used to measure both nicotine and PAH in indoor air.

Chuang, J.C.; Kuhlman, M.R.; Wilson, N.K.

1990-01-01

13

EVALUATION OF A METHOD FOR SAMPLING AND ANALYSIS OF NICOTINE AND POLYNUCLEAR AROMATIC HYDROCARBONS IN INDOOR AIR  

EPA Science Inventory

A study was performed to determine whether one sampling system and one analytical method can be used to measure both polynuclear aromatic hydrocarbons (PAH) and nicotine. he PAH collection efficiencies for both XAD-2 and XAD-4 adsorbents are very similar, but the nicotine collect...

14

Contribution of wood combustion to indoor air pollution as measured by mutagenicity in Salmonella and polycyclic aromatic hydrocarbon concentration  

Microsoft Academic Search

Samples of airborne particles have been collected in the same room when the room was heated by electricity and when heating was done by woodburning. These samples were compared with respect to mutagenic activity and concentration of polycyclic aromatic hydrocarbons (PAH). The effects of the various heating conditions were examined in the presence and absence of tobacco smoking. Whereas wood

Ingrid Alfheim; Thomas Ramdahl

1984-01-01

15

Particulate matter and particle-attached polycyclic aromatic hydrocarbons in the indoor and outdoor air of Tokyo measured with personal monitors.  

PubMed

Using two types of personal monitors for suspended particulate matter of diameter under 10 microm (PM-10) and for particles of diameter under 1 microm with attached polycyclic aromatic hydrocarbons (PPAH), we measured the PM-10 and PPAH concentrations in the indoor and outdoor air in various locations in the Tokyo area. The major findings were as follows. (1) The PPAH concentrations in a clean living room increased rapidly within several minutes after one cigarette was smoked. (2) Using the average indoor concentrations of PM-10 and PPAH in a department store as control concentrations, respectively, where the average indoor PM-10 concentration was closest to an annual average outdoor concentration in Japan, the mean value for indoor air concentrations of PM-10 by location ranged from 2.2 to 6.2 times the control concentration, and the mean value for indoor air concentrations of PPAH by location ranged from 1.0 to 32.2 times the control concentration. (3) Using the same control concentrations, the mean value of outdoor concentrations of PM-10 by location ranged from 1.6 to 8.5 times the control concentration, while the mean value of outdoor concentrations of PPAH by location were up to 353.7 times the control concentration. The major polluted places were main traffic roads, highways, and street tunnels. (4) The correlation coefficient between the PM and the PPAH concentrations in the total monitoring time was 0.014, which was not significant (P>0.05). PMID:12051787

Sakai, Ryoji; Siegmann, Hans C; Sato, Hajime; Voorhees, A Scott

2002-05-01

16

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

17

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.

18

Biodegradation of polycyclic aromatic hydrocarbons  

Microsoft Academic Search

The intent of this review is to provide an outline of the microbial degradation of polycyclic aromatic hydrocarbons. A catabolically diverse microbial community, consisting of bacteria, fungi and algae, metabolizes aromatic compounds. Molecular oxygen is essential for the initial hydroxylation of polycyclic aromatic hydrocarbons by microorganisms. In contrast to bacteria, filamentous fungi use hydroxylation as a prelude to detoxification rather

Carl E. Cerniglia

1992-01-01

19

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

20

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

PubMed Central

Emission factors (EFs) of parent polycyclic aromatic (pPAHs), nitrated PAHs (nPAHs), and oxygenated PAHs (oPAHs) were measured for indoor corn straw burned in a cooking brick stove in both normal and controlled burning conditions. EFs of total 28 pPAHs, 6 nPAHs and 4 oPAHs were 7.9±3.4, 6.5±1.6×10-3, and 6.1±1.4×10-1 mg/kg, respectively. By controlling the burning conditions, it was found that the influence of fuel charge size on EFs of the pPAHs and derivatives was insignificant. Measured EFs increased significantly in a fast burning mainly because of the oxygen deficient atmosphere formed in the stove chamber with a small volume. In both restricted and enhance air supply conditions, EFs of pPAHs, nPAHs and oPAHs were significantly higher than those measured in normal burning conditions. Though EFs varied in 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 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, Bin; Wu, Haisuo; Tao, Shu

2014-01-01

21

Polarography of Benzenoid Aromatic Hydrocarbons  

Microsoft Academic Search

This review summarises the results of the study of the reduction and oxidation in protogenic, aprotic, and strongly acidic solutions of benzenoid polynuclear aromatic hydrocarbons whose molecules do not contain electrochemically active substituents. The characteristic features of the adsorption of aromatic hydrocarbons on mercury and various other metals are noted. The bibliography contains 167 references.

Stepan I. Zhdanov

1969-01-01

22

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

23

Effects of Floor Level and Building Type on Residential Levels of Outdoor and Indoor Polycyclic Aromatic Hydrocarbons, Black Carbon, and Particulate Matter in New York City  

PubMed Central

Consideration of the relationship between residential floor level and concentration of traffic-related airborne pollutants may predict individual residential exposure among inner city dwellers more accurately. Our objective was to characterize the vertical gradient of residential levels of polycyclic aromatic hydrocarbons (PAH; dichotomized into ?8PAHsemivolatile (MW 178–206), and ?8PAHnonvolatile (MW 228–278), black carbon (BC), PM2.5 (particulate matter) by floor level (FL), season and building type. We hypothesize that PAH, BC and PM2.5 concentrations may decrease with higher FL and the vertical gradients of these compounds would be affected by heating season and building type. PAH, BC and PM2.5 were measured over a two-week period outdoor and indoor of the residences of a cohort of 5–6 year old children (n = 339) living in New York City’s Northern Manhattan and the Bronx. Airborne-pollutant levels were analyzed by three categorized FL groups (0–2nd, 3rd–5th, and 6th–32nd FL) and two building types (low-rise versus high-rise apartment building). Indoor ?8PAHnonvolatile and BC levels declined with increasing FL. During the nonheating season, the median outdoor ?8PAHnonvolatile, but not ?8PAHsemivolatile, level at 6th–2nd FL was 1.5–2 times lower than levels measured at lower FL. Similarly, outdoor and indoor BC concentrations at 6th–32nd FL were significantly lower than those at lower FL only during the nonheating season (p < 0.05). In addition, living in a low-rise building was associated significantly with higher levels of ?8PAHnonvolatile and BC. These results suggest that young inner city children may be exposed to varying levels of air pollutants depending on their FL, season, and building type. PMID:21886868

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

2011-01-01

24

Effects of heating season on residential indoor and outdoor polycyclic aromatic hydrocarbons, black carbon, and particulate matter in an urban birth cohort  

NASA Astrophysics Data System (ADS)

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 ? 8PAH semivolatile (MW 178-206), and ? 8PAH nonvolatile (MW 228-278)), Abs, and PM 2.5; and 2) assess the relationship between PAH and ozone. Results showed that heating compared to nonheating season was associated with greater ? 8PAH nonvolatile ( p < 0.001) and Abs ( p < 0.05), and lower levels of ? 8PAH semivolatile ( p < 0.001). In addition, the heating season was associated with lower I/O ratios of ? 8PAH nonvolatile and higher I/O ratios of ? 8PAH semivolatile ( p < 0.001) compared to the nonheating season. In outdoor air, ? 8PAH nonvolatile 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.

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.

2010-11-01

25

Personal and indoor exposure to PM?.? and polycyclic aromatic hydrocarbons in the southern highlands of Tanzania: a pilot-scale study.  

PubMed

Personal and indoor exposure to PM(2.5) and polycyclic aromatic hydrocarbons (PAHs) were measured in households in the Njombe district of Tanzania. Cooking is conducted indoors in this region due to its high elevation, cool climate, and heavy seasonal rainfall. Kitchens are often poorly ventilated, resulting in high exposures to combustion-related pollutants. Sampling sites were selected to represent typical cooking practices across regional socio-economic divisions. These include the use of open wood fires, charcoal, a mix of charcoal and kerosene, and liquid petroleum gas (LPG) for cooking fuels. PM(2.5) average personal exposure was 14 ?g/m(3) (±3, n = 3) for LPG, 88 ?g/m(3) (±42, n = 3) for kerosene/charcoal mix, 588 ?g/m(3) (±347, n?= 3) for charcoal alone, and 1574 ?g/m(3) (±287, n = 3) for open wood fires. Total PAH average personal exposures were less than 1 ng/m(3) (±1, n = 3) for LPG, 57 ng/m(3) (±16, n = 3) for kerosene/charcoal mix, 334 ng/m(3) (±57, n = 3) for charcoal alone, and 5040 ng/m(3) (±909, n = 3) for open wood fires. Benzo[a]pyrene equivalent exposures for US EPA's priority PAH pollutants were 0 for LPG, 8 ng/m(3) for kerosene/charcoal mix, 44 ng/m(3) for charcoal, and 767 ng/m(3) for open wood fire. Inhalable pollutants are present at unacceptably high levels, exceeding indoor air quality standards for all but LPG fuels. Relative results provide an exposure profile for rural East Africa and support the feasibility of conducting a larger scale smoke exposure campaign in the region. The use of "fuel efficient" wood stoves for the reduction of PM(2.5) and PAH exposure was measured in a local secondary school. Proper use of "fuel efficient" wood stoves reduced personal and indoor exposure to measured pollutants by more than 90%, supporting further investigation into the applicability of this technology to significantly improve indoor air quality. PMID:21136289

Titcombe, Mari E; Simcik, Matt

2011-09-01

26

Bioassay of polycyclic aromatic hydrocarbons  

SciTech Connect

A positive relationship was found between the photodynamic activity of 24 polycyclic aromatic hydrocarbons versus published results on the mutagenicity, carcinogenicity, and initiation of unscheduled DNA synthesis. Metabolic activation of benzo(a)pyrene resulted in detection of increased mutagenesis in Paramecium tetraurelia as found also in the Ames Salmonella assay. The utility of P. tetraurelia as a biological detector of hazardous polycyclic aromatic hydrocarbons is discussed.

Van Kirk, E.A.

1980-08-01

27

Estimating individual-level exposure to airborne polycyclic aromatic hydrocarbons throughout the gestational period based on personal, indoor, and outdoor monitoring  

SciTech Connect

Current understanding on health effects of long-term polycyclic aromatic hydrocarbon (PAH) exposure is limited by lack of data on time-varying nature of the pollutants at an individual level. In a cohort of pregnant women in Krakow, Poland, we examined the contribution of temporal, spatial, and behavioral factors to prenatal exposure to airborne PAHs within each trimester and developed a predictive model of PAH exposure over the entire gestational period. The observed personal, indoor, and outdoor B(a)P levels we observed in Krakow far exceed the recommended Swedish guideline value for B(a)P of 0.1 ng/m{sup 3}. Based on simultaneously monitored levels, the outdoor PAH level alone accounts for 93% of total variability in personal exposure during the heating season. Living near the Krakow bus depot, a crossroad, and the city, center and time spent outdoors or commuting were not associated with higher personal exposure. During the nonheating season only, a 1-hr increase in environmental tobacco smoke (ETS) exposure was associated with a 10-16% increase in personal exposure to the nine measured PAHs. A 1{degree}C decrease in ambient temperature was associated with a 3-5% increase in exposure to benz(a)anthracene, benzo(k)fluoranthene, and dibenz(a,h)anthracene, after accounting for the outdoor concentration. A random effects model demonstrated that mean personal exposure at a given gestational period depends on the season, residence location, and ETS. Considering that most women reported spending < 3 hr/day outdoors, most women in the study were exposed to outdoor-originating PAHs within the indoor setting. Cross-sectional, longitudinal monitoring supplemented with questionnaire data allowed development of a gestation-length model of individual-level exposure with high precision and validity.

Choi, H.; Perera, F.; Pac, A.; Wang, L.; Flak, E.; Mroz, E.; Jacek, R.; Chai-Onn, T.; Jedrychowski, W.; Masters, E.; Camann, D.; Spengler, J. [Columbia University, New York, NY (United States)

2008-11-15

28

Polycyclic aromatic hydrocarbon bioremediation design  

Microsoft Academic Search

Many polycyclic aromatic hydrocarbons (PAHs) are known to be mutagenic or carcinogenic, and their contamination in soil and aquifer is of great environmental concern. Limited numbers of microorganisms including mycobacteria, Sphingomonas and white rot fungi were found to be capable of degrading PAHs with four or more fused aromatic rings. In white rot fungi, lignin peroxidases are believed to be

Shigeaki Harayama

1997-01-01

29

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...

30

Quantification of Polycyclic Aromatic Hydrocarbons and Aliphatic Hydrocarbons in Air Particulate Samples in Homes  

Microsoft Academic Search

Quantifications of 10 polycyclic aromatic hydrocarbons (PAHs) and 13 aliphatic hydrocarbons (AHs) ranging from n-C20 to n-C32 were reported in 17 homes and their adjacent outdoor environment in Hong Kong. It was found that PAHs were predominantly associated with PM1.9, which contributed about 98 and 97% to the indoor and outdoor PM10 PAHs, respectively. Also, indoor PAH levels seemed to

Christopher Y. H. Chao; Lam-Lung Yeung; Patience S. H. Choi

2002-01-01

31

Quantification of Polycyclic Aromatic Hydrocarbons and Aliphatic Hydrocarbons in Air Particulate Samples in Homes  

Microsoft Academic Search

Quantifications of 10 polycyclic aromatic hydrocarbons (PAHs) and 13 aliphatic hydrocarbons (AHs) ranging from n-C20 to n-C32 were reported in 17 homes and their adjacent outdoor environment in Hong Kong. It was found that PAHs were predominantly associated with PM1.9, which contributed about 98 and 97% to the indoor and outdoor PM10 PAHs, respectively. Also, indoor PAH levels seemed to

Christopher Y. H. Chao; Lam-Lung Yeung; Patience S. H. Choi

2002-01-01

32

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

33

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...

34

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...

35

Polycyclic Aromatic Hydrocarbon Structure Index  

NSDL National Science Digital Library

The Polycyclic Aromatic Hydrocarbon (PAH) Index, a special publication from the National Institute of Standards and Technology, provides the structures of a large number of PAHs. In addition to the structure, the Index lists other names for the compound, CAS number, molecular weight, length-to-breadth ratio, width, length, and thickness. Users can search the PAH Index via compound name and molecular weight, browse alphabetically, or scan cover to cover. An introduction to the Index is available in [.pdf] format.

Sander, Lane C.

1997-01-01

36

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 ...

37

[Polycyclic aromatic hydrocarbons in air].  

PubMed

Polycyclic aromatic hydrocarbons (PAHs) are a large group of organic compounds consisting of two or more condense aromatic rings. They are products of incomplete combustion or pyrolysis of organic matter. Because some PAHs such as Benzo[a]pyrene (BaP) are proven carcinogens and mutagens, it is necessary to continuously monitor their concentrations in the air, water, and soil. PAHs with two or three aromatic rings are stable in the gas phase, while most PAHs with five or more aromatic rings bond to particles. Higher concentrations of PAHs are present in the atmosphere of urban areas, mostly in the winter, due to heating. In the summer, these concentrations drop because most PAHs are unstable at high temperatures and break down by oxidation and photooxidation. Measurements of PAHs in the air include sampling on the filter paper or solid adsorbent, extraction, and chromatographic analysis. This review presents the measurements of BaP in some locations in the world and compares them with the findings in Croatia. PMID:22202470

Jakovljevi?, Ivana; Zužul, Silva

2011-12-01

38

Birds and polycyclic aromatic hydrocarbons  

USGS Publications Warehouse

Polycyclic aromatic hydrocarbons (PAH) are present throughout the global environment and are produced naturally and by activities of humans. Effects of PAH on birds have been determined by studies employing egg injection, egg immersion, egg shell application, single and multiple oral doses, subcutaneous injection, and chemical analysis of field-collected eggs and tissue. The four-to six-ring aromatic compounds are the most toxic to embryos, young birds, and adult birds. For embryos, effects include death, developmental abnormalities, and a variety of cellular and biochemical responses. For adult and young birds, effects include reduced egg production and hatching, increased clutch or brood abandonment, reduced growth, increased organweights, and a variety of biochemical responses. Trophic level accumulation is unlikely. Environmental exposure to PAH in areas of high human population or habitats affected by recent petroleum spills might be sufficient to adversely affect reproduction. Evidence of long-term effects of elevated concentrations of environmental PAH on bird populations is very limited and the mechanisms of effect are unclear.

Albers, P.H.

2006-01-01

39

Polynuclear aromatic hydrocarbons for fullerene synthesis in flames  

DOEpatents

This invention provides improved methods for combustion synthesis of carbon nanomaterials, including fullerenes, employing multiple-ring aromatic hydrocarbon fuels selected for high carbon conversion to extractable fullerenes. The multiple-ring aromatic hydrocarbon fuels include those that contain polynuclear aromatic hydrocarbons. More specifically, multiple-ring aromatic hydrocarbon fuels contain a substantial amount of indene, methylnapthalenes or mixtures thereof. Coal tar and petroleum distillate fractions provide low cost hydrocarbon fuels containing polynuclear aromatic hydrocarbons, including without limitation, indene, methylnapthalenes or mixtures thereof.

Alford, J. Michael; Diener, Michael D.

2006-12-19

40

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

41

Infrared spectra of polycyclic aromatic hydrocarbons (PAHs)  

Microsoft Academic Search

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

C. W. Bauschlicher; E. L. O. Bakes

2000-01-01

42

Infrared spectra of polycyclic aromatic hydrocarbons (PAHs)  

NASA Astrophysics Data System (ADS)

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

Bauschlicher, C. W.; Bakes, E. L. O.

2000-12-01

43

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...

44

PROTONATED POLYCYCLIC AROMATIC HYDROCARBONS REVISITED  

SciTech Connect

We reconsider the contribution that singly protonated polycyclic aromatic hydrocarbons (PAHs; HPAH{sup +}s) might make to the Class A component of the 6.2 {mu}m interstellar emission feature in light of the recent experimental measurements of protonated naphthalene and coronene. Our calculations on the small HPAH{sup +}s have a band near 6.2 {mu}m, as found in experiment. While the larger HPAH{sup +}s still have emission near 6.2 {mu}m, the much larger intensity of the band near 6.3 {mu}m overwhelms the weaker band at 6.2 {mu}m, so that the 6.2 {mu}m band is barely visible. Since the large PAHs are more representative of those in the interstellar medium, our work suggests that large HPAH{sup +}s cannot be major contributors to the observed emission at 6.2 {mu}m (i.e., Class A species). Saturating large PAH cations with hydrogen atoms retains the 6.2 {mu}m Class A band position, but the rest of the spectrum is inconsistent with observed spectra.

Ricca, Alessandra [Carl Sagan Center, SETI Institute, 189 N. Bernardo Ave., 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)

2011-02-01

45

Polycyclic aromatic hydrocarbons: levels and phase distributions in preschool microenvironment.  

PubMed

This work aims to characterize levels and phase distribution of polycyclic aromatic hydrocarbons (PAHs) in indoor air of preschool environment and to assess the impact of outdoor PAH emissions to indoor environment. Gaseous and particulate (PM1 and PM2.5 ) PAHs (16 USEPA priority pollutants, plus dibenzo[a,l]pyrene, and benzo[j]fluoranthene) were concurrently sampled indoors and outdoors in one urban preschool located in north of Portugal for 35 days. The total concentration of 18 PAHs (?PAHs) in indoor air ranged from 19.5 to 82.0 ng/m(3) ; gaseous compounds (range of 14.1-66.1 ng/m(3) ) accounted for 85% ?PAHs. Particulate PAHs (range 0.7-15.9 ng/m(3) ) were predominantly associated with PM1 (76% particulate ?PAHs) with 5-ring PAHs being the most abundant. Mean indoor/outdoor ratios (I/O) of individual PAHs indicated that outdoor emissions significantly contributed to PAH indoors; emissions from motor vehicles and fuel burning were the major sources. PMID:25263282

Oliveira, M; Slezakova, K; Delerue-Matos, C; Pereira, M C; Morais, S

2014-09-29

46

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

47

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

E-print Network

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

Zare, Richard N.

48

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...

49

Polycyclic aromatic hydrocarbons: environmental pollution and bioremediation  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs) are widely distributed and relocated in the environment as a result of the incomplete combustion of organic matter. Many PAHs and their epoxides are highly toxic, mutagenic and\\/or carcinogenic to microorganisms as well as to higher systems including humans. Although various physicochemical methods have been used to remove these compounds from our environment, they have many

Sudip K Samanta; Om V Singh; Rakesh K Jain

2002-01-01

50

Multipathway Polycyclic Aromatic Hydrocarbon and Pyrene Exposure Among Children Living in Campania (Italy)  

Microsoft Academic Search

Multipathway exposure to Polycyclic aromatic hydrocarbons (PAHs) and Pyrene (Py) was studied among children ages 7–9 living in two areas of the Campania Region (South-Italy) classified as urban and rural. During five consecutive days PAHs and Py were detected in air samples from outdoors, indoors (school and home), individuals at inhalatory levels, and in food and beverages (defined as food)

TERESA CIRILLO; PAOLO MONTUORI; PIERANGELA MAINARDI; IMMA RUSSO; MARIA TRIASSI; RENATA AMODIO-COCCHIERI

2006-01-01

51

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

52

Monitoring of vapor phase polycyclic aromatic hydrocarbons  

DOEpatents

An apparatus for monitoring vapor phase polycyclic aromatic hydrocarbons in a high-temperature environment has an excitation source producing electromagnetic radiation, an optical path having an optical probe optically communicating the electromagnetic radiation received at a proximal end to a distal end, a spectrometer or polychromator, a detector, and a positioner coupled to the first optical path. The positioner can slidably move the distal end of the optical probe to maintain the distal end position with respect to an area of a material undergoing combustion. The emitted wavelength can be directed to a detector in a single optical probe 180.degree. backscattered configuration, in a dual optical probe 180.degree. backscattered configuration or in a dual optical probe 90.degree. side scattered configuration. The apparatus can be used to monitor an emitted wavelength of energy from a polycyclic aromatic hydrocarbon as it fluoresces in a high temperature environment.

Vo-Dinh, Tuan; Hajaligol, Mohammad R.

2004-06-01

53

Atmospheric polycyclic aromatic hydrocarbons in Seoul, Korea  

Microsoft Academic Search

Daily particulate- and vapor-phase polycyclic aromatic hydrocarbons (PAH) samples were collected at an urban site in Seoul, Korea, during five intensive sampling campaigns between October 1998 and December 1999. PAH samples collected on quartz fiber filters and PUF plugs were first extracted using dichloromethane with ultrasonication and supercritical fluid extraction methods, respectively, and then analyzed by GC\\/MSD\\/SIM. Seasonal trends in

Seung S. Park; Young J. Kim; Chang H. Kang

2002-01-01

54

Carbon fibers from aromatic hydrocarbons  

SciTech Connect

Carbon filter is widely used as a lightweight and high-strength material for composite structures. Its uses are expected to expand in the next century. Currently the best precursor for making these fibers is polyacrylonitrile (PAN). This is a relatively expensive feedstock. Carbon fibers also have been made starting with so-called mesophase pitch fractions derived from low-cost hydrocarbons such as petroleum residuum. But these fibers suffer from low mechanical strength. In the past few years, significant advances have been made in understanding the mechanism of formation of mesophase pitch, which may lead to improved performance for carbon fibers and other specialty carbons. This article introduces such advances, based principally on the authors` recent results.

Mochida, Isao; Yoon, S.H.; Korai, Yozo; Kanno, Koichi; Sakai, Yukio; Komatsu, Makoto [Kyushu Univ. (Japan)

1995-02-01

55

Extension of Electron Affinities and Ionization Potentials of Aromatic Hydrocarbons  

Microsoft Academic Search

The absolute molecular electronegativities for 14 aromatic hydrocarbons are reported. For the hydrocarbons considered, a linear relationship exists between the electron affinity and the energy of the 1La transition. The molecular electronegativity for some eight aromatic hydrocarbons is approximately constant. On this basis, it is possible to predict some ionization potentials which are in excellent agreement with recent experimental values.

Ralph S. Becker; Edward Chen

1966-01-01

56

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). ...

57

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...

58

Potency Equivalency Factors for Some Polycyclic Aromatic Hydrocarbons and Polycyclic Aromatic Hydrocarbon Derivatives  

Microsoft Academic Search

Potency equivalency factors (PEFs) for cancer induction relative to benzo[a]pyrene have been derived for 21 polycyclic aromatic hydrocarbons (PAHs) and PAH derivatives based on a data preference scheme. PEFs have been derived only for PAHs with demonstrated carcinogenicity in bioassays. Cancer potency values and inhalation unit risks are presented for four additional carcinogenic PAHs based on expedited risk assessments conducted

J. F. Collins; J. P. Brown; G. V. Alexeeff; A. G. Salmon

1998-01-01

59

Estimation of nitropolycyclic aromatic hydrocarbons in foods.  

PubMed

A method is described for the sample clean-up and estimation of nitropolycyclic aromatic hydrocarbons (nitro-PAH) in foods. The analysis involves the novel use of a coupled capillary gas chromatograph/thermal energy analyser and provides a detection limit for 1-nitropyrene of 12 pg (equivalent to 0.02 micrograms/kg for a 50-g sample). Only 3 out of 24 samples contained detectable quantities of nitro-PAHs; these were in the range 0.2-2.0 micrograms/kg. In contrast to the widespread occurrence of the parent PAHs in foodstuffs, the presence of nitro-derivatives appears to be minimal. PMID:6085686

Dennis, M J; Massey, R C; McWeeny, D J; Knowles, M E

1984-01-01

60

Degradation of mixtures of aromatic and chloroaliphatic hydrocarbons by aromatic hydrocarbon-degrading bacteria.  

PubMed

The well-characterized toluene-oxidizing bacteria Pseudomonas putida PaW1, P. putida F1, P. mendocina KR1, Burkholderia cepacia G4, B. cepacia JS150, and Ralstonia pickettii PKO1, as well as several strains of bacteria isolated from activated sludge, were examined for their ability to degrade mixtures of aromatic and chloroaliphatic hydrocarbons. Collectively, the strains tested were able to transform all of the 14 aromatic hydrocarbons included in the mixtures, with most strains degrading five or more. Few strains degraded trichloroethylene well under these conditions, only one degraded methylene chloride, and none were able to transform chloroform. G4, PKO1, KR1, F1, and JS150 exhibited generally broad but oxygenase-specific degradation profiles, with the three monooxygenase strains degrading significantly more o-xylene and trichloroethylene, and F1 and JS150 degrading greater quantities of isopropylbenzene and 1,4-dichlorobenzene. PaW1 degraded only the methylaromatic hydrocarbons and styrene. Sludge isolates enriched on benzene, toluene, styrene and the xylenes exhibited degradation profiles similar to F1 or PaW1, while the pattern of hydrocarbon degradation for the ethylbenzene, isopropylbenzene, 1,3,5-trimethylbenzene, and 1,3-dichlorobenzene isolates were distinct from the other strains and from each other. Overall, our results showed that many of the bacteria which utilize aromatic compounds are capable of degrading a diverse array of aromatic hydrocarbons in mixtures, but that chloroaliphatics such as methylene chloride and chloroform may be recalcitrant to co-oxidation in the presence of aromatics or trichloroethylene. PMID:19719688

Leahy, Joseph G; Tracy, Karen D; Eley, Michael H

2003-03-01

61

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...

62

.. Polycyclic aromatic hydrocarbons in nearshore marine sediments of Australia*  

E-print Network

143 . .. Polycyclic aromatic hydrocarbons in nearshore marine sediments of Australia* W.A. Maher and J. Aislabiet Water Research Centre, University of Canberra, PO Box /, Belconnen,ACT 26/6, Australia aromatic hydrocarbons (PAH) in nearshore marine sediments of Australia isdiscussed. Available information

Canberra, University of

63

Simplified determination of polycyclic aromatic hydrocarbons.  

PubMed

Accurate quantitative analysis for selected polycyclic aromatic hydrocarbons present on urban dust can be obtained by using a simple procedure consisting of sonic-probe extraction with cyclohexane; clean-up with Florisil((R))-XAD-4((R)), and measurement by high-resolution gas chromatography with flame-ionization detection (HRGC/FID). The analysis can be further simplified by eliminating the clean-up step if HRGC/electron-impact mass-spectrometry (MS) is available. Both the FID and MS methods give results consistent with those obtained by standard procedures. The direct HRGC/MS procedure, combined with chemical ionization, can also be applied to the determination of polycyclic organic materials present in solvent-refined coal, shale oil and crude oil. PMID:18963526

Avery, M J; Richard, J J; Junk, G A

1984-01-01

64

Coumarin, Naphthalene, and Additional Polycyclic Aromatic Hydrocarbons  

NSDL National Science Digital Library

The featured molecules this month are drawn from two papers. The first, "One-Pot Synthesis of 7-Hydroxy-3-carboxycoumarin in Water", is a Green Chemistry feature by Fringuelli, Piermatti, and Pizzo. The three-dimensional versions of the molecules in the synthesis of the coumarin derivative are directly tied to the reaction scheme included in the paper, opening the possibility of showing large numbers of complex synthetic pathways in this manner.The second paper is "Determining the Carbon-Carbon Distance in an Organic Molecule with a Ruler" by Simoni, Tubino, and Ricchi. This article describes an experiment to determine the size of a naphthalene molecule, using an extension of classic experiments for determining molecular size and Avogadro's number. While the structure of naphthalene will come as no surprise to most students, the molecule collection also includes additional polycyclic aromatic hydrocarbons (PAHs) that can be used to introduce students to the environmental and health issues related to these molecules.

65

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

66

Ions colliding with polycyclic aromatic hydrocarbon clusters  

NASA Astrophysics Data System (ADS)

We have measured the ionization and fragmentation of polycyclic aromatic hydrocarbon (PAH) molecules and their clusters. We find that PAH clusters containing up to roughly 100 individual molecules fragment strongly following collisions with keV ions in low or high charge states (q). For both types of collisions, singly charged PAH molecules are found to be the dominant products but for very different reasons. A high-q ion projectile charge leads to strong multiple ionization of the PAH clusters and subsequent Coulomb explosions. A low-q ion projectile charge often leads to single ionization but stronger internal heating and long evaporation sequences with a singly charged PAH monomer as the end product. We have developed a Monte Carlo method for collision-induced heating of PAH clusters and present an evaporation model where the clusters cool slowly as most of the internal energies are stored in intramolecular vibrations and not in molecule-molecule vibrations.

Gatchell, M.; Zettergren, H.; Seitz, F.; Chen, T.; Alexander, J. D.; Stockett, M. H.; Schmidt, H. T.; ?awicki, A.; Rangama, J.; Rousseau, P.; Capron, M.; Maclot, S.; Maisonny, R.; Domaracka, A.; Adoui, L.; Méry, A.; Chesnel, J.-Y.; Manil, B.; Huber, B. A.; Cederquist, H.

2013-09-01

67

The cytopathologic effects of specific aromatic hydrocarbons.  

PubMed Central

A heterogeneous mixture of the aromatic hydrocarbons benzene, toluene, and xylene is capable of inducing cellular lesions among selected organs of the fat-head minnow at the respective concentrations of 10.7, 7.4, and 2.7 mg/l. The gill, pseudobranch, liver, and nasal mucosa of experimental fish were exposed for a period of 6, 12, 24, or 48 hours to the hydrocarbons, whose source was the water-soluble fraction of jet aviation fuel JP-4. While many of the initial cellular changes appeared reversible, the extent and magnitude of injury increased as the exposure period progressed, with an apparent concomitant development of irreversible lesions. Manifestations of cytotoxicity among cells of the gill included multivesiculated blebs, distended mitochondria, intercellular spaces between surface and underlying epithelial layers, and evaginations of the endothelial lining associated with capillaries of secondary lamellae. Cells comprising the pseudobranch were characterized by a significant increase in lipidlike droplets, proliferation of cytoplasmic vacuoles, and disruption of the normally ordered association of mitochondria and tubules. The nasal mucosa was characterized by a loss of cilia and cellular necrosis within the underlying epithelial layers. Cytotoxicity among hepatocytes was evident in the forms of vesiculated endoplasmic reticulum and both swollen and condensed mitochondria. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18 Figure 19 Figure 20 Figure 21 Figure 22 PMID:3976842

Norton, W. N.; Mattie, D. R.; Kearns, C. L.

1985-01-01

68

Partially oxidized polycyclic aromatic hydrocarbons show an increased bioavailability and biodegradability  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons have a low water solubility and tend to adsorb on soil particles, which both result in slow bioremediation processes. Many microorganisms, known for their ability to degrade polycyclic aromatic hydrocarbons, only partially oxidize these compounds. White rot fungi, for instance, convert polycyclic aromatic hydrocarbons to more water soluble and bioavailable products. Polycyclic aromatic hydrocarbon metabolites were more

Rogier Meulenberg; Huub H. M Rijnaarts; Hans J Doddema; Jim A Field

1997-01-01

69

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...

70

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...

71

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...

72

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

73

Biodegradability of select polycyclic aromatic hydrocarbon (pah) mixtures  

E-print Network

Polycyclic aromatic hydrocarbons (PAHs) are environmentally significant because of their ubiquity and the toxicity of some. Their recalcitrance and persistence makes them problematic environmental contaminants. Microbial degradation is considered...

Desai, Anuradha M.

2007-04-25

74

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....

75

BIODEGRADATION OF POLYCYCLIC AROMATIC HYDROCARBONS BY PHANEROCHAETE CHRYSOSPORIUM  

EPA Science Inventory

The ability of the white rot fungus Phanerochaete chrysosporium to degrade polycyclic aromatic hydrocarbons (PAHS) that are present in anthracene oil (a distillation product obtained from coal tar) was demonstrated. nalysis by capillary gas chromatography and high-performance liq...

76

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...

77

PHOTOTOXICITY OF POLYCYCLIC AROMATIC HYDROCARBONS IN COASTAL GREAT LAKES WATERS  

EPA Science Inventory

Photoinduced toxicity is the exacerbated toxicity of environmental contaminants by UV radiation. Photoinduced toxicity of polycyclic aromatic hydrocarbons (PAHs) has been well established in the laboratory for numerous aquatic species including larval fish. The contaminants sub-p...

78

Polycyclic Aromatic Hydrocarbons in Interstellar Medium Dust  

NASA Astrophysics Data System (ADS)

We obtained spectra from the Spitzer Space Telescope Infrared Spectrometer (IRS) of lines of sight that probe large columns of diffuse interstellar medium (ISM) dust (PID 3616, J. Chiar). An absorption feature at 6.2 ?m, that we attribute to polycyclic aromatic hydrocarbons (PAHs) in the cold ISM, is detected in nine of our spectra. PAHs are normally observed in emission near an exciting source, rather than in the cold ISM dust, however, Schutte et al. (1998, A&A, 337, 261) found the 6.2 ?m absorption feature in spectra of WC-type Wolf-Rayet stars that probed moderate columns of diffuse ISM dust. However, it was later shown by Chiar et al. (2001, ApJ, 550, 207) that the feature could be attributed to circumstellar dust around these objects. A low limit was set on lack of detection in the diffuse ISM. Our new Spitzer spectra provide the first indisputable detections of the 6.2 ?m PAH absorption feature toward stars that are not associated with circumstellar dust. Based on our nine detections and twenty detection limits, a positive correlation is suggested between the optical depth of the 6.2 ?m absorption feature and visual extinction. If verified (with higher signal-to-noise data), this relationship would imply that PAHs are widespread components of cold ISM dust, similar to the well-known aliphatic hydrocarbons that peak at 3.4 ?m. Assuming an elemental carbon abundance of C/H=3.7 x 10-4, we estimate that 30 to 40% of the interstellar carbon can be tied up in PAH dust. Future high signal-to-noise observations with SOFIA and/or the James Webb Space Telescope will be crucial to verify the nature and distribution of PAHs in cold ISM dust. This material is based upon work supported by the National Science Foundation under Grant No. 0552751.

Malsberger, Rosalie; Chiar, J. E.; Tielens, A. G. G. M.; Sloan, G. C.

2009-01-01

79

Polycyclic aromatic hydrocarbons and childhood asthma.  

PubMed

Asthma is the most common chronic illness in children living in developed countries and the leading cause of childhood hospitalization and school absenteeism. Prevalence rates of asthma are increasing and show disparities across gender, geographic regions, and ethnic/racial groups. Common risk factors for developing childhood asthma include exposure to tobacco smoke, previous allergic reactions, a family history of asthma, allergic rhinitis or eczema, living in an urban environment, obesity and lack of physical exercise, severe lower respiratory tract infections, and male gender. Asthma exacerbation in children can be triggered by a variety of factors, including allergens (e.g., pollen, dust mites, and animal dander), viral and bacterial infections, exercise, and exposure to airway irritants. Recent studies have shown that exposure to polycyclic aromatic hydrocarbons (PAHs), a major component of fine particulate matter from combustion sources, is also associated with onset of asthma, and increasing asthmatic symptoms. In this paper, we review sources of childhood PAH exposure and the association between airborne PAH exposure and childhood asthma prevalence and exacerbation. PMID:25600297

Karimi, Parisa; Peters, Kamau O; Bidad, Katayoon; Strickland, Paul T

2015-02-01

80

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

81

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

82

Natural adsorbents for the purification of aromatic hydrocarbons  

Microsoft Academic Search

The adsorbents used in purifying aromatic hydrocarbons are clays that have been heattreated; these clays may be active in the natural state, or they may be activated by acid, caustic, or salt. The high activity of natural clays with respect to unsaturated hydrocarbons, along with their low cost, are factors favoring their extensive commercial use. The most promising clays for

M. M. Kuvaeva; R. V. Alekseeva; L. I. Kalinina; M. Sh. Sovozu

1984-01-01

83

Anaerobic degradation of non-substituted aromatic hydrocarbons.  

PubMed

Aromatic hydrocarbons are among the most prevalent organic pollutants in the environment. Their removal from contaminated systems is of great concern because of the high toxicity effect on living organisms including humans. Aerobic degradation of aromatic hydrocarbons has been intensively studied and is well understood. However, many aromatics end up in habitats devoid of molecular oxygen. Nevertheless, anaerobic degradation using alternative electron acceptors is much less investigated. Here, we review the recent literature and very early progress in the elucidation of anaerobic degradation of non-substituted monocyclic (i.e. benzene) and polycyclic aromatic hydrocarbons (PAH such as naphthalene and phenanthrene). A focus will be on benzene and naphthalene as model compounds. This review concerns the microbes involved, the biochemistry of the initial activation and subsequent enzyme reactions involved in the pathway. PMID:21398107

Meckenstock, Rainer U; Mouttaki, Housna

2011-06-01

84

In vitro toxicity of polycyclic aromatic hydrocarbons and halogenated aromatic hydrocarbons to cetacean cells and tissues  

SciTech Connect

Cetaceans bioaccumulate high aromatic hydrocarbon tissue residues, and elevated levels of PCB residues in tissues are proposed to have occurred concurrently with recent epizootic deaths of dolphins. The objectives of this study were: (1) to develop and characterize an epithelial cell line derived from dolphin tissues, (2) to investigate the effects of hydrocarbon pollutants on those cells, and (3) to analyze the toxicity of hydrocarbon pollutants on cetacean tissues in vitro. An epithelial cell line, Carvan dolphin kidney (CDK), isolated from a spontaneously aborted female bottlenose dolphin, Tursiops truncatus, grew rapidly. These cells were neither transformed nor immortal. Velocity sedimentation analysis showed CDK cells contained nuclear aryl hydrocarbon receptor, suggestive of cytochrome P450 inducibility. BaP inhibited mitosis in CDK cells in a dose-dependent manner. Data indicate that CDK cells metabolize BaP, that BaP metabolites bind to cellular DNA initiating unscheduled DNA synthesis, and that the inhibition of cytochrome P450 metabolism decrease the BaP-associated inhibition of mitosis in dolphin cells. The data also suggest that TCDD acts synergistically to increase the levels of DNA damage by the procarcinogen BaP. Cetacean liver microsomes was isolated and evaluated for the presence of cytochrome P450 proteins by SDS-PAGE, apparent minimum molecular weight determination, and immunoblot analysis. P450 activity was induced in cetacean tissue samples and CDK cells by exposure in vitro to one of several cytochrome P450-inducing chemicals. The data suggest that cetacean tissues and cells can be utilized to study the in vitro induction of cytochrome P450, resultant metabolism of xenobiotic contaminants, and the subsequent cellular and molecular responses. However, the identity of specific P450 isozymes involved in this process will remain undetermined until monoclonal antibodies that recognize cetacean P450s can be generated.

Carvan, M.J. III.

1993-01-01

85

Polycyclic Aromatic Hydrocarbon Far-infrared Spectroscopy  

NASA Astrophysics Data System (ADS)

The far-IR characteristics of astrophysically relevant polycyclic aromatic hydrocarbons (PAHs) averaging in size around 100 carbon atoms have been studied using the theoretical spectra in the NASA Ames PAH IR Spectroscopic Database. These spectra were calculated using density functional theory. Selections of PAH species are made, grouped together by common characteristics or trends, such as size, shape, charge, and composition, and their far-IR spectra compared. The out-of-plane modes involving the entire molecule are explored in detail, astronomical relevance is assessed, and an observing strategy is discussed. It is shown that PAHs produce richer far-IR spectra with increasing size. PAHs also produce richer far-IR spectra with increasing number of irregularities. However, series of irregular-shaped PAHs with the same compact core have common "Jumping-Jack" modes that "pile up" at specific frequencies in their average spectrum. For the PAHs studied here, around 100 carbon atoms in size, this band falls near 50 ?m. PAH charge and nitrogen inclusion affect band intensities but have little effect on far-IR band positions. Detailed analysis of the two-dimensional, out-of-plane bending "drumhead" modes in the coronene and pyrene "families" and the one-dimensional, out-of-plane bending "bar" modes in the acene "family" show that these molecular vibrations can be treated as classical vibrating sheets and bars of graphene, respectively. The analysis also shows that the peak position of these modes is very sensitive to the area of the emitting PAH and does not depend on the particular geometry. Thus, these longest wavelength PAH bands could provide a unique handle on the size of the largest species in the interstellar PAH family. However, these bands are weak. Observing highly excited regions showing the mid-IR bands in which the emission from classical dust peaks at short wavelengths offers the best chance of detecting PAH emission in the far-IR. For these regions sensitivity is not an issue, spectral contrast is maximized and the PAH population is only comprised of highly stable, compact symmetric PAHs, such as the members of the pyrene and coronene "families" discussed in detail here.

Boersma, C.; Bauschlicher, C. W., Jr.; Ricca, A.; Mattioda, A. L.; Peeters, E.; Tielens, A. G. G. M.; Allamandola, L. J.

2011-03-01

86

Closed-Shell Polycyclic Aromatic Hydrocarbon Cations: A New Category of Interstellar Polycyclic Aromatic Hydrocarbons  

NASA Technical Reports Server (NTRS)

Density functional theory has been employed to calculate the harmonic frequencies and intensities of a range of polycyclic aromatic hydrocarbon (PAH) cations that explore both size and electronic structure effects of the infrared spectroscopic properties of these species. The sample extends the size range of PAH species considered to more than 50 carbon atoms and includes several representatives from each of two heretofore unexplored categories of PAH cations: (1) fully benzenoid PAH cations whose carbon skeleton is composed of an odd number of carbon atoms (C(sub odd) PAHs); and (2) protonated PAH cations (HPAH+). Unlike the radical electronic structures of the PAH cations that have been the subject of previous theoretical and experimental work, the species in these two classes have a closed-shell electronic configuration. The calculated spectra of circumcoronene, C54H18 in both neutral and (radical) cationic form are also reported and compared with those of the other species. Overall, the C(sub odd) PAHs spectra are dominated by strong CC stretching modes near 1600 cm(exp -1) and display spectra that are remarkably insensitive to molecular size. The HPAH+ species evince a more complex spectrum consistent with the added contributions of aliphatic modes and their generally lower symmetry. Finally, for both classes of closed-shell cations, the intensity of the aromatic CH stretching modes is found to increase with molecular size far out of proportion with the number of CH groups, approaching a value more typical of neutral PAHs for the largest species studied.

Hudgins, Douglas M.; Bauschlicher, Charles W., Jr.; Allamandola, Louis J.; DeVincenzi, Donald (Technical Monitor)

2001-01-01

87

Exposure to polycyclic aromatic hydrocarbons among Dutch children.  

PubMed Central

We determined the urinary 1-hydroxypyrene (1-HP) concentration and the creatinine-adjusted 1-HP concentration in 644 randomly selected Dutch children, aged 1-6 years and living in five areas with roughly different levels of polycyclic aromatic hydrocarbons (PAHs) in soil and ambient air. The presence of other factors that might influence the exposure to PAHs was studied using a questionnaire. To evaluate the reliability of a single urinary 1-HP determination, measurements were repeated after 3 weeks for approximately 200 children. The mean urinary 1-HP content of the total study population was 2.06 nmol/l. This varied from 1.58 nmol/l in the reference area (Flevoland) to 2.71 nmol/l in the valley of the Geul. Only indoor sources of PAHs showed a small, positive association with urinary 1-HP. The urinary 1-HP concentrations of children from the valley of the Geul were higher (p < 0.01) and those of children from a suburb of Amsterdam were lower (p < 0.01) than those of children from the reference area. The possible ambient environment-related differences were probably too small to be detected in the variations of the intake of PAHs from the daily diet. The reliability of a single 1-HP measurement was low. Similar results were obtained with the creatinine-adjusted data. In one neighborhood built on coal-mine tailings, the urinary 1-HP content in children was weakly but positively associated with the PAH content in the upper soil layer of the garden of their homes. However, this association was not found for the children from the other neighborhood built on coal-mine tailings and with similar PAH levels in soil. PMID:8743441

van Wijnen, J H; Slob, R; Jongmans-Liedekerken, G; van de Weerdt, R H; Woudenberg, F

1996-01-01

88

75 FR 8937 - Development of a Relative Potency Factor (RPF) Approach for Polycyclic Aromatic Hydrocarbon (PAH...  

Federal Register 2010, 2011, 2012, 2013, 2014

...RPF) Approach for Polycyclic Aromatic Hydrocarbon (PAH) Mixtures'' (EPA/635/R-08...RPF) Approach for Polycyclic Aromatic Hydrocarbon (PAH) Mixtures'' is available primarily...consider your comment. Instructions: Direct your comments to Docket ID No....

2010-02-26

89

Polycyclic aromatic hydrocarbon and petroleum hydrocarbon contamination in sediment from the Newark Bay estuary, New Jersey  

Microsoft Academic Search

The presence of numerous industrial and municipal sources such as former creosote wood preserving facilities, petroleum storage and refinery facilities, paint and chemical manufacturers, combined sewer overflows, and sewage treatment facilities along the shores of Newark Bay, New Jersey and its major tributaries suggests the potential for widespread contamination by polycyclic aromatic hydrocarbons (PAHs) and petroleum hydrocarbons. In this study,

S. L. Huntley; N. L. Bonnevie; R. J. Wenning

1995-01-01

90

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

91

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.

92

Aust. J. Mar. Freshw. Res., 1984, 35, 119-28 Aromatic Hydrocarbons in Waters of  

E-print Network

of fossil fuels. Crude oils contain 7-35% (w/w) aromatic hydrocarbons (Gilchrist et al. 1972Aust. J. Mar. Freshw. Res., 1984, 35, 119-28 Aromatic Hydrocarbons in Waters of Port Phillip Bay of aromatic hydrocarbons in coastal waters, using solvent extraction and fluorescence emission analysis, shows

Canberra, University of

93

Development of a Fluorescence Polarization Immunoassay for Polycyclic Aromatic Hydrocarbons  

Microsoft Academic Search

A fluorescence polarization immunoassay for detection of polycyclic aromatic hydrocarbons (PAHs) was developed. Fluorescein?labeled tracers based on different PAHs were synthesized and studied in order to achieve a high sensitivity using both monoclonal and polyclonal antibodies. The application of different combinations of antibody tracer pairs allows to separately determine groups of small and large PAHs or to realize a class?specific

Irina Yu Goryacheva; Sergei A. Eremin; Ekaterina A. Shutaleva; Miloslav Suchanek; Reinhard Niessner; Dietmar Knopp

2007-01-01

94

Polycyclic aromatic hydrocarbons in San Francisco Estuary sediments  

E-print Network

Polycyclic aromatic hydrocarbons in San Francisco Estuary sediments Daniel R. Oros*, John R.M. Ross pair ratios as indicators showed that PAH are derived primarily from combustion of fossil fuels power plants) with combustion turbines that operate on petroleum distillate fuel and natural gas

95

Interactions of polyhalogeneted aromatic hydrocarbons with thyroid hormone metabolism  

Microsoft Academic Search

This thesis deals with the possible interactions of polyhalogenated aromatic hydrocarbons and\\/or their metabolites with thyroid hormone metabolism. This chapter summarizes firstly the effects of thyroid hormone on the induction of biotransformation enzymes by PHAHs. Secondly, the results on the inhibition of thyroid hormone sulfation by hydroxylated metabolites of PHAH are summarized. Some conclusions and remarks on the overall implications

A. G. Schuur

1998-01-01

96

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

97

Atmospheric transport and outflow of polycyclic aromatic hydrocarbons from China  

Microsoft Academic Search

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

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

2008-01-01

98

Polycyclic aromatic hydrocarbons in fuel-oil contaminated soils, Antarctica  

Microsoft Academic Search

Where fuel oil spills have occurred on Antarctic soils polycyclic aromatic hydrocarbons (PAH) may accumulate. Surface and subsurface soil samples were collected from fuel spill sites up to 30 years old, and from nearby control sites, and analysed for the 16 PAHs on the USEPA priority pollutants list, as well as for two methyl substituted naphthalenes, 1-methylnaphthalene and 2-methylnaphthalene. PAH

Jackie Aislabie; Megan Balks; Norma Astori; Gavin Stevenson; Robert Symons

1999-01-01

99

AGRONOMIC OPTIMIZATION FOR PHYTOREMEDIATION OF POLYCYCLIC AROMATIC HYDROCARBONS  

EPA Science Inventory

Phytoremediation is a low-cost method of using plants to degrade, volatilize or sequester organic and metal pollutants that has been used in efforts to remediate sites contaminated with polycyclic aromatic hydrocarbon (PAH) refinery wastes. Non-native plant species aggressivel...

100

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

101

Sampling of airborne polycyclic aromatic hydrocarbons with semipermeable membrane devices  

Microsoft Academic Search

Semipermeable membrane devices (SPMDs) are nowadays used as passive samplers of organic pollutants. The knowledge of the sampling rate values ( R S) of each substance trapped on membranes is necessary to calculate their average concentration. Here we calculate R S values for 16 polycyclic aromatic hydrocarbons using the comparison of active sampling method results and the amounts sequestered by

J. ?áslavský; P. Kotla?íková; K. Benešová

2004-01-01

102

Effect of bioremediation on polycyclic aromatic hydrocarbon residues in soil  

Microsoft Academic Search

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

Xiaoping Wang; Xiaobing Yu; Richard Bartha

1990-01-01

103

Solubilization of polycyclic aromatic hydrocarbons in micellar nonionic surfactant solutions  

Microsoft Academic Search

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

David A. Edwards; Richard G. Luthy; Zhongbao Liu

1991-01-01

104

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...

105

Enhanced Bioremediation of Polycyclic Aromatic Hydrocarbons by Environmentally Friendly Techniques  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs) are recognized as a worldwide environmental contamination problem because of their intrinsic chemical stability, high resistance to various transformation processes, and toxicity property. Because of the wide distribution of the PAHs in the environment, human exposure to the PAHs is likely to occur from dermal contact, ingestion of particles, inhalation of airborne dust, or bioaccumulation in

Huey-Min Hwang; Xiaoke Hu; Xueheng Zhao

2007-01-01

106

Ambient aromatic hydrocarbon measurements at Welgegund, South Africa  

NASA Astrophysics Data System (ADS)

Aromatic hydrocarbons are associated with direct adverse human health effects and can have negative impacts on ecosystems due to their toxicity, as well as indirect negative effects through the formation of tropospheric ozone and secondary organic aerosol, which affect human health, crop production and regional climate. Measurements of aromatic hydrocarbons were conducted at the Welgegund measurement station (South Africa), which is considered to be a regionally representative background site. However, the site is occasionally impacted by plumes from major anthropogenic source regions in the interior of South Africa, which include the western Bushveld Igneous Complex (e.g. platinum, base metal and ferrochrome smelters), the eastern Bushveld Igneous Complex (platinum and ferrochrome smelters), the Johannesburg-Pretoria metropolitan conurbation (> 10 million people), the Vaal Triangle (e.g. petrochemical and pyrometallurgical industries), the Mpumalanga Highveld (e.g. coal-fired power plants and petrochemical industry) and also a region of anticyclonic recirculation of air mass over the interior of South Africa. The aromatic hydrocarbon measurements were conducted with an automated sampler on Tenax-TA and Carbopack-B adsorbent tubes with heated inlet for 1 year. Samples were collected twice a week for 2 h during daytime and 2 h during night-time. A thermal desorption unit, connected to a gas chromatograph and a mass selective detector was used for sample preparation and analysis. Results indicated that the monthly median (mean) total aromatic hydrocarbon concentrations ranged between 0.01 (0.011) and 3.1 (3.2) ppb. Benzene levels did not exceed the local air quality standard limit, i.e. annual mean of 1.6 ppb. Toluene was the most abundant compound, with an annual median (mean) concentration of 0.63 (0.89) ppb. No statistically significant differences in the concentrations measured during daytime and night-time were found, and no distinct seasonal patterns were observed. Air mass back trajectory analysis indicated that the lack of seasonal cycles could be attributed to patterns determining the origin of the air masses sampled. Aromatic hydrocarbon concentrations were in general significantly higher in air masses that passed over anthropogenically impacted regions. Inter-compound correlations and ratios gave some indications of the possible sources of the different aromatic hydrocarbons in the source regions defined in the paper. The highest contribution of aromatic hydrocarbon concentrations to ozone formation potential was also observed in plumes passing over anthropogenically impacted regions.

Jaars, K.; Beukes, J. P.; van Zyl, P. G.; Venter, A. D.; Josipovic, M.; Pienaar, J. J.; Vakkari, V.; Aaltonen, H.; Laakso, H.; Kulmala, M.; Tiitta, P.; Guenther, A.; Hellén, H.; Laakso, L.; Hakola, H.

2014-07-01

107

Aromatic hydrocarbon "humps" in the marine environment: unrecognized toxins?  

PubMed

Gas chromatographic analysis of the hydrocarbons of environmental samples often reveals that unresolved complex mixtures (UCMs) or gas chromatographic "humps" of aliphatic and aromatic hydrocarbons are most abundant--yet little consideration seems to have been given to the possible toxicological impacts of hydrocarbon "humps". Here we show, using a well-accepted bioassay, that monoaromatic components of a UCM of hydrocarbons from a crude oil elicit a sublethal toxic response in a typical marine pollution indicator organism (the mussel, Mytilus edulis). Furthermore, coastal U.K. mussels shown previously to have unexplained impaired health contained high concentrations of UCMs, including monoaromatic UCMs. These findings may have important implications for our understanding of the toxicological sublethal effects of oil residues in the environment. Given the relatively resistant nature of UCM hydrocarbons, the effects of both acute oil spills and more chronic discharges may need further consideration. PMID:11452586

Rowland, S; Donkin, P; Smith, E; Wraige, E

2001-07-01

108

Biodegradation of aliphatic vs. aromatic hydrocarbons in fertilized arctic soils  

USGS Publications Warehouse

A study was carried out to test a simple bioremediation treatment strategy in the Arctic and analyze the influence of fertilization the degradation of aliphatic and aromatic hydrocarbons, e.g., pristine, n-tetradecane, n-pentadecane, 2-methylnaphthalene, naphthalene, and acenaphthalene. The site was a coarse sand pad that once supported fuel storage tanks. Diesel-range organics concentrations were 250-860 mg/kg soil at the beginning of the study. Replicate field plots treated with fertilizer yielded final concentrations of 0, 50, 100, or 200 mg N/kg soil. Soil pH and soil-water potentials decreased due to fertilizer application. The addition of fertilizer considerably increased soil respiration potentials, but not the populations of microorganisms measured. Fertilizer addition also led to ??? 50% loss of measured aliphatic and aromatic hydrocarbons in surface and subsurface soils. For fertilized plots, hydrocarbon loss was not associated with the quantity of fertilizer added. Losses of aliphatic hydrocarbons were ascribed to biotic processes, while losses of aromatic hydrocarbons were due to biotic and abiotic processes.

Braddock, J.F.

1999-01-01

109

Effect of fluorine substitution on the aromaticity of polycyclic hydrocarbons.  

PubMed

The effect of fluorine substitution on the aromaticity of polycyclic hydrocarbons (PAH) is investigated. Magnetically induced current densities, current pathways, and current strengths, which can be used to assess molecular aromaticity, are calculated using the gauge-including magnetically induced current method (GIMIC). The degree of aromaticity of the individual rings is compared to those obtained using calculated nucleus-independent chemical shifts at the ring centers (NICS(0) and NICS(0)(zz)). Calculations of explicitly integrated current strengths for selected bonds show that the aromatic character of the investigated polycyclic hydrocarbons is weakened upon fluorination. In contrast, the NICS(0) values for the fluorinated benzenes increase noteworthy upon fluorination, predicting a strong strengthening of the aromatic character of the arene rings. The integrated current strengths also yield explicit current pathways for the studied molecules. The current pathways of the investigated linear polyacenes, pyrene, anthanthrene, coronene, ovalene, and phenanthro-ovalene are not significantly affected by fluorination. NISC(0) and NICS(0)(zz) calculations provide contradictory degrees of aromaticity of the fused individual ring. Obtained NICS values do not correlate with the current strengths circling around the individual rings. PMID:22994485

Kaipio, Mikko; Patzschke, Michael; Fliegl, Heike; Pichierri, Fabio; Sundholm, Dage

2012-10-18

110

Conversion of light alkanes into aromatic hydrocarbons  

SciTech Connect

The aromatization of propane at 530[degrees]C on three MFI gallosilicates (Si/Ga = 30, 50 and 180) and on a MFI aluminosilicates (Si/Al = 30) was investigated. After pretreatment at 530[degrees]C under dry air flow, 30 Al MFI was seven times more active than 30 Ga MFI. This can be related to the greater strength of the acid sites of the aluminosilicate sample, which was shown by a calorimetric study of ammonia adsorption and by ammonia thermodesorption. Large differences were found in the catalytic product distribution, namely a lower initial cracking/dehydrogenation ration on 30 Ga MFI, greater selectivity to aromatics, and lower selectivity to alkanes (C[sub 1], C[sub 2], C[sub 4]) at high conversion, which can be explained by a dehydrogenating effect of gallium. The product distribution depended also on the Si/Ga ratio of the gallosilicate, a better selectivity to aromatics being found with 30 Ga MFI. The selectivity differences are mainly due to differences in the acid site density. The treatment of gallosilicates at 700-800[degrees]C under dry air flow caused a significant increase in their activity and in their selectivity for propane aromatization. This could be related to the formation of a small amount of extraframework gallium species, well dispersed in the crystallites and highly active for dehydrogenation of propane and of naphthene intermediates. On these catalysts propane aromatization occurred mainly through a bifunctional scheme and the formation of unwanted C[sub 1]C[sub 2] products, though acid cracking was very limited. The effect of the pretreatment temperature on the acid and dehydrogenating activity of the 30 Ga MFI sample showed that framework gallium species were much less active for dehydrogenation than extraframework species and indeed are probably inactive. 26 refs., 9 figs., 1 tab.

Giannetto, G. (Universidad Central de Venezuela, Los Chaguaramos, Caracas (Venezuela)); Montes, A. (Instituto Universitario de Technologia, Caracas (Venezuela)); Gnep, N.S.; Florentino, A.; Cartraud, P.; Guisnet, M. (Universite de Poitiers, Poitiers (France))

1994-01-01

111

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

112

SOLUBILITY BEHAVIOR OF THREE AROMATIC HYDROCARBONS IN DISTILLED WATER AND NATURAL SEAWATER  

EPA Science Inventory

The solubilities of three aromatic hydrocarbons were determined at 25 C. in natural seawater and distilled water. Saturation was achieved by equilibration of water and an excess of hydrocarbon by mechanical agitation. All three hydrocarbons, toluene, acenaphthene, and pyrene, wer...

113

Biodegradation of aromatic hydrocarbons in an extremely acidic environment  

SciTech Connect

The potential for biodegradation of aromatic hydrocarbons was evaluated in soil samples recovered along gradients of both contaminant levels and pH values existing downstream of a long-term coal pile storage basin. pH values for areas greatly impacted by runoff from the storage basin were 2.0. Even at such a reduced pH, the indigenous microbial community was metabolically active, showing the ability to oxidize more than 40% of the parent hydrocarbons, naphthalene and toluene, to carbon dioxide and water. Treatment of the soil samples with cycloheximide inhibited mineralization of the aromatic substrates. DNA hybridization analysis indicated that whole-community nucleic acids recovered from these samples did not hybridize with genes, such as nahA, nahG, nahH, todC1C2, and tomA, that encode common enzymes from neutrophilic bacteria. Since these data suggested that the degradation of aromatic compounds may involve a microbial consortium instead of individual acidophilic bacteria, experiments using microorganisms isolated from these samples were initiated. While no defined mixed cultures were able to evolve {sup 14}CO{sub 2} from labeled substrates in these mineralization experiments, an undefined mixed culture including a fungus, a yeast, and several bacteria successfully metabolized approximately 27% of supplied naphthalene after 1 week. This study shows that biodegradation of aromatic hydrocarbons can occur in environments with extremely low pH values.

Stapleton, R.D.; Savage, D.C.; Sayler, G.S.; Stacey, G. [Univ. of Tennessee, Knoxville, TN (United States)

1998-11-01

114

Biodegradation of Aromatic Hydrocarbons in an Extremely Acidic Environment  

PubMed Central

The potential for biodegradation of aromatic hydrocarbons was evaluated in soil samples recovered along gradients of both contaminant levels and pH values existing downstream of a long-term coal pile storage basin. pH values for areas greatly impacted by runoff from the storage basin were 2.0. Even at such a reduced pH, the indigenous microbial community was metabolically active, showing the ability to oxidize more than 40% of the parent hydrocarbons, naphthalene and toluene, to carbon dioxide and water. Treatment of the soil samples with cycloheximide inhibited mineralization of the aromatic substrates. DNA hybridization analysis indicated that whole-community nucleic acids recovered from these samples did not hybridize with genes, such as nahA, nahG, nahH, todC1C2, and tomA, that encode common enzymes from neutrophilic bacteria. Since these data suggested that the degradation of aromatic compounds may involve a microbial consortium instead of individual acidophilic bacteria, experiments using microorganisms isolated from these samples were initiated. While no defined mixed cultures were able to evolve 14CO2 from labeled substrates in these mineralization experiments, an undefined mixed culture including a fungus, a yeast, and several bacteria successfully metabolized approximately 27% of supplied naphthalene after 1 week. This study shows that biodegradation of aromatic hydrocarbons can occur in environments with extremely low pH values. PMID:9797263

Stapleton, Raymond D.; Savage, Dwayne C.; Sayler, Gary S.; Stacey, Gary

1998-01-01

115

Exciton properties of selected aromatic hydrocarbon systems  

NASA Astrophysics Data System (ADS)

We have examined the singlet excitons in two representatives of acene-type (tetracene and pentacene) and phenacene-type (chrysene and picene) molecular crystals, respectively, using electron energy-loss spectroscopy at low temperatures. We show that the excitation spectra of the two hydrocarbon families significantly differ. Moreover, close inspection of the data indicates that there is an increasing importance of charge-transfer excitons at lowest excitation energy with increasing length of the molecules.

Roth, Friedrich; Mahns, Benjamin; Hampel, Silke; Nohr, Markus; Berger, Helmuth; Büchner, Bernd; Knupfer, Martin

2013-02-01

116

Ambient aromatic hydrocarbon measurements at Welgegund, South Africa  

SciTech Connect

Aromatic hydrocarbons are associated with direct adverse human health effects and can have negative impacts on ecosystems due to their toxicity, as well as indirect negative effects through the formation of tropospheric ozone and secondary organic aerosol that affect human health, crop production and regional climate. Measurements were conducted at the Welgegund measurement station (South Africa) that is considered to be a regionally representative background site. However, the site is occasionally impacted by plumes from major anthropogenic source regions in the interior of South Africa, which include the western Bushveld Igneous Complex (e.g. platinum, base metal and ferrochrome smelters), the eastern Bushveld Igneous Complex (platinum and ferrochrome smelters), the Johannesburg-Pretoria metropolitan conurbation (>10 million people), the Vaal Triangle (e.g. petrochemical and industries), the Mpumalanga Highveld (e.g. coal-fired power plants and petrochemical industry) and also a region of anti-cyclonic recirculation of air mass over the interior of South Africa. The aromatic hydrocarbon measurements were conducted with an automated sampler on Tenax-TA and Carbopack-B adsorbent tubes with heated inlet for one year. Samples were collected twice a week for two hours during daytime and two hours 1 during night-time. A thermal desorption unit, connected to a gas chromatograph and a mass 2 selective detector was used for sample preparation and analysis. Results indicated that the 3 monthly median total aromatic hydrocarbon concentrations ranged between 0.01 to 3.1 ppb. 4 Benzene levels did not exceed local air quality standards. Toluene was the most abundant 5 species, with an annual median concentration of 0.63 ppb. No statistically significant 6 differences in the concentrations measured during daytime and night-time were found and no distinct seasonal patterns were observed. Air mass back trajectory analysis proved that the lack of seasonal cycles could be attributed to patterns determining the origin of the air masses sampled. Aromatic hydrocarbon concentrations were in general significantly higher in air masses that passed over anthropocentrically impacted regions. Interspecies correlations and ratios gave some indications of the possible sources for the different aromatic hydrocarbons in the source regions defined in the paper. The highest contribution of aromatic hydrocarbon concentrations to ozone formation potential was also observed in plumes passing over anthropocentrically impacted regions.

Jaars, K.; Beukes, J. P.; van Zyl, P. G.; Venter, A. D.; Josipovic, M.; Pienaar, J. J.; Vakkari, Ville; Aaltonen, H.; Laakso, H.; Kulmala, M.; Tiitta, P.; Guenther, Alex B.; Hellen, H.; Laakso, L.; Hakola, H.

2014-07-11

117

Ambient aromatic hydrocarbon measurements at Welgegund, South Africa  

NASA Astrophysics Data System (ADS)

Aromatic hydrocarbons are associated with direct adverse human health effects and can have negative impacts on ecosystems due to their toxicity, as well as indirect negative effects through the formation of tropospheric ozone and secondary organic aerosol that affect human health, crop production and regional climate. Measurements were conducted at the Welgegund measurement station (South Africa) that is considered to be a regionally representative background site. However, the site is occasionally impacted by plumes from major anthropogenic source regions in the interior of South Africa, which include the western Bushveld Igneous Complex (e.g. platinum, base metal and ferrochrome smelters), the eastern Bushveld Igneous Complex (platinum and ferrochrome smelters), the Johannesburg-Pretoria metropolitan conurbation (>10 million people), the Vaal Triangle (e.g. petrochemical and pyrometallurgical industries), the Mpumalanga Highveld (e.g. coal-fired power plants and petrochemical industry) and also a region of anti-cyclonic recirculation of air mass over the interior of South Africa. The aromatic hydrocarbon measurements were conducted with an automated sampler on Tenax-TA and Carbopack-B adsorbent tubes with heated inlet for one year. Samples were collected twice a week for two hours during daytime and two hours during night-time. A thermal desorption unit, connected to a gas chromatograph and a mass selective detector was used for sample preparation and analysis. Results indicated that the monthly median total aromatic hydrocarbon concentrations ranged between 0.01 to 3.1 ppb. Benzene levels did not exceed local air quality standards. Toluene was the most abundant species, with an annual median concentration of 0.63 ppb. No statistically significant differences in the concentrations measured during daytime and night-time were found and no distinct seasonal patterns were observed. Air mass back trajectory analysis proved that the lack of seasonal cycles could be attributed to patterns determining the origin of the air masses sampled. Aromatic hydrocarbon concentrations were in general significantly higher in air masses that passed over anthropocentrically impacted regions. Interspecies correlations and ratios gave some indications of the possible sources for the different aromatic hydrocarbons in the source regions defined in the paper. The highest contribution of aromatic hydrocarbon concentrations to ozone formation potential was also observed in plumes passing over anthropocentrically impacted regions.

Jaars, K.; Beukes, J. P.; van Zyl, P. G.; Venter, A. D.; Josipovic, M.; Pienaar, J. J.; Vakkari, V.; Aaltonen, H.; Laakso, H.; Kulmala, M.; Tiitta, P.; Guenther, A.; Hellén, H.; Laakso, L.; Hakola, H.

2014-02-01

118

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.

119

Phenalenyl-based open-shell polycyclic aromatic hydrocarbons.  

PubMed

The phenalenyl radical is a polycyclic aromatic hydrocarbon (PAH) radical. Owing to its widely distributed spin structure, phenalenyl is relatively stable compared to other hydrocarbon radicals and has been studied from the viewpoint of its application to electroconductive and magnetic materials. In addition, a strong intermolecular spin-spin coupling nature is another feature of phenalenyl. This account summarizes my studies so far into PAH radicals containing the phenalenyl scaffold in terms of their amphoteric redox properties and singlet biradical character, which strongly rely on the characteristic electronic structure, that is, non-bonding character and sixfold symmetry of a singly occupied molecular orbital of the phenalenyl radical. PMID:25345729

Kubo, Takashi

2015-02-01

120

The conformation of some nitro-polycyclic aromatic hydrocarbons  

NASA Astrophysics Data System (ADS)

The Raman spectra of some nitro-polycyclic aromatic hydrocarbons, including 2-nitroanthracene, 7-nitrobenz[a]anthracene, 6-nitrochrysene, 1-nitropyrene, 6-nitrobenzo[a]pyrene, and 6-nitro-7,8,9,10-tetrahydrobenzo[a]pyrene, have been recorded in the frequency region 1100-1700 cm -1. The stretching vibrational modes for the nitro group in each of these compounds were assigned based on group frequencies, the measured infrared and Raman spectra, the relative spectral intensities, and the Raman depolarization data. From the measured Raman depolarization data, the orientation of the nitro-substituent with respect to polycyclic aromatic hydrocarbon was determined for each of these compounds except 6-nitro-7,8,9,10-tetrahydrobenzo[a]pyrene. The results were correlated with the direct-acting mutagenicity of the nitro compounds according to the hypothesis suggested by P.P. Fu and his co-workers.

Li, Y. S.; Fu, P. P.; Church, J. S.

2000-09-01

121

Cardiac autonomic dysfunction from occupational exposure to polycyclic aromatic hydrocarbons  

Microsoft Academic Search

ObjectivesExposure to polycyclic aromatic hydrocarbons (PAHs) has been associated with cardiopulmonary mortality and cardiovascular events. This study investigated the association between a biological marker of PAH exposure, assessed by urinary 1-hydroxypyrene (1-OHP), and heart-rate variability in an occupational cohort of boilermakers.MethodsContinuous 24 h monitoring of the ambulatory electrocardiogram (ECG) and pre- and postshift urinary 1-OHP were repeated over extended periods

Mi-Sun Lee; Shannon Magari; David C Christiani

2010-01-01

122

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

123

Polycyclic aromatic hydrocarbon distributions in Mississippi Fan sediments  

E-print Network

. Sandberg, B. A. , University of Colorado Chairman of Advisory Committee: Dr. James M. Brooks Polycyclic aromatic hydrocarbon (PAH) distributions in Upper Pleistocene sediments of the Mississippi Fan and two intraslope basins in the Gulf of Mexico... of Mexico. PAH and alkane concentrations, and molecular level distributions within PAH homologous series generally covary at all sites. Based on statistical data, PAH distributions, and the geological setting, one possible explanation for the observed...

Sandberg, William Allan

1986-01-01

124

Polycyclic Aromatic Hydrocarbon Ecotoxicity Data for Developing Soil Quality Criteria  

Microsoft Academic Search

With the overall perspective of calculating soil quality criteria (SQC) for the group of polycyclic aromatic hydrocarbons\\u000a (PAHs), the existing ecotoxicity data for the soil compartment have been reviewed. The majority of data useful in the context\\u000a of deriving SQC are of recent origin. Soil quality criteria are considered valuable tools for assessing the environmental\\u000a risk of contamination, as they

John Jensen; Line E. Sverdrup

125

Screening of ectomycorrhizal fungi for degradation of polycyclic aromatic hydrocarbons  

Microsoft Academic Search

Ectomycorrhizal fungi belonging to 16 species (27 strains) were tested for their ability to degrade polycyclic aromatic hydrocarbons\\u000a (PAHs): phenanthrene, chrysene, pyrene and benzo[a]pyrene. Cultivated on a complex liquid medium, most of the fungi tested were able to metabolise these compounds. Approximately\\u000a 50% of the benzo[a]pyrene was removed by strains of Amanita excelsa, Leccinum versipelle, Suillus grevillei, S. luteus, and

A. Braun-Lüllemann; A. Hüttermann; A. Majcherczyk

1999-01-01

126

Polycyclic aromatic hydrocarbons in some grounded coffee brands.  

PubMed

Potentially toxic 16 priority polycyclic aromatic hydrocarbons (PAHs) were determined in four brands of grounded coffee. Four to 13 PAHs were detected. Concentrations of total PAHs in different brands of coffee samples were in the range of 831.7-1,589.7 ?g/kg. Benzo[a]pyrene (2A: probable human carcinogen) was found in Nescafe Premium whereas naphthalene (2B: possible human carcinogen) was found in all the samples of coffee. PMID:23242460

Grover, Inderpreet Singh; Sharma, Rashmi; Singh, Satnam; Pal, Bonamali

2013-08-01

127

Risk assessment of polycyclic aromatic hydrocarbons in aquatic ecosystems  

Microsoft Academic Search

A probability risk assessment of anthracene, benzo(a)pyrene, chrysene, fluorene, phenanthrene and pyrene was carried out to\\u000a examine the ecological risk of these six polycyclic aromatic hydrocarbons (PAHs) in aquatic ecosystems in China. The literature\\u000a on PAH concentrations in surface water in China was collected to evaluate the environmental exposure concentrations (EEC).\\u000a The 10th percentile of predicted no observed effect concentration

Bing WuRui; Rui Zhang; Shu-Pei Cheng; Timothy Ford; Ai-Min Li; Xu-Xiang Zhang

2011-01-01

128

Polycyclic aromatic hydrocarbon metabolic network in Mycobacterium vanbaalenii PYR-1.  

PubMed

This study investigated a metabolic network (MN) from Mycobacterium vanbaalenii PYR-1 for polycyclic aromatic hydrocarbons (PAHs) from the perspective of structure, behavior, and evolution, in which multilayer omics data are integrated. Initially, we utilized a high-throughput proteomic analysis to assess the protein expression response of M. vanbaalenii PYR-1 to seven different aromatic compounds. A total of 3,431 proteins (57.38% of the genome-predicted proteins) were identified, which included 160 proteins that seemed to be involved in the degradation of aromatic hydrocarbons. Based on the proteomic data and the previous metabolic, biochemical, physiological, and genomic information, we reconstructed an experiment-based system-level PAH-MN. The structure of PAH-MN, with 183 metabolic compounds and 224 chemical reactions, has a typical scale-free nature. The behavior and evolution of the PAH-MN reveals a hierarchical modularity with funnel effects in structure/function and intimate association with evolutionary modules of the functional modules, which are the ring cleavage process (RCP), side chain process (SCP), and central aromatic process (CAP). The 189 commonly upregulated proteins in all aromatic hydrocarbon treatments provide insights into the global adaptation to facilitate the PAH metabolism. Taken together, the findings of our study provide the hierarchical viewpoint from genes/proteins/metabolites to the network via functional modules of the PAH-MN equipped with the engineering-driven approaches of modularization and rationalization, which may expand our understanding of the metabolic potential of M. vanbaalenii PYR-1 for bioremediation applications. PMID:21725022

Kweon, Ohgew; Kim, Seong-Jae; Holland, Ricky D; Chen, Hongyan; Kim, Dae-Wi; Gao, Yuan; Yu, Li-Rong; Baek, Songjoon; Baek, Dong-Heon; Ahn, Hongsik; Cerniglia, Carl E

2011-09-01

129

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

130

Ambient air pollution by aromatic hydrocarbons in Algiers  

NASA Astrophysics Data System (ADS)

The analysis of the C 6-C 16 semi-volatile organic compounds reveals the presence of numerous aromatic hydrocarbons in the ambient air of Algiers. Three representative sites were chosen for sample collection at roadside, urban background and semi-rural areas. The following major monocyclic aromatic hydrocarbons were found: benzene, toluene, ethylbenzene, ( m, p)- and o-xylene, also referred to as BTEX. Near the road traffic, benzene and toluene mean concentrations were 27 and 39 ?g m -3, respectively, with benzene concentration values higher than 40 ?g m -3 often observed. At the urban site, the benzene concentration often exceeds the European regulatory limit of 10 ?g m -3 while the compositional ratios of toluene to benzene and ( m- p) xylene to ethylbenzene are within the typical range of values observed in urban atmospheres worldwide. The seasonal variation indicates a decrease in concentration during summer of the reactive o-xylene compound. It is suggested that Algiers' source of high-level air pollution by aromatic hydrocarbons is related to car traffic emissions.

Kerbachi, Rabah; Boughedaoui, Ménouèr; Bounoua, Lahouari; Keddam, Malika

131

Mutagenic and carcinogenic properties of polycyclic aromatic hydrocarbons.  

PubMed Central

The rapid development of the chemical industry, combustion of fossil fuels, and smoking of tobacco have resulted in contact of the general population with benzo(a)pyrene and other carcinogenic aromatic hydrocarbons. Persons especially at risk occupationally are those engaged in thermal processing of oil shale, coal, and heavy residual petroleum. It has been shown that polycyclic aromatic hydrocarbons require metabolic activation before they can act as mutagens or carcinogens. This metabolic activation results from interaction with microsomal enzymes present in many body cells, yielding reactive epoxides which react with DNA and produce mutations in the count frame shift or participate in covalent bounding. While opinions differ regarding the relative role of these processes in mutagenesis, considerable evidence exists which links mutagenesis and carcinogenesis. Metabolites of the polycyclic aromatic hydrocarbons which are carcinogenic are usually mutagenic, which supports the hypothesis that damage to chromosomes plays an important role in carcinogenesis. These facts open the possibility to monitoring the spread of carcinogenic substances in the biosphere by relatively simple tests whose endpoint is mutagenesis. PMID:446450

Pashin, Y V; Bakhitova, L M

1979-01-01

132

Mutagenic and carcinogenic properties of polycyclic aromatic hydrocarbons.  

PubMed

The rapid development of the chemical industry, combustion of fossil fuels, and smoking of tobacco have resulted in contact of the general population with benzo(a)pyrene and other carcinogenic aromatic hydrocarbons. Persons especially at risk occupationally are those engaged in thermal processing of oil shale, coal, and heavy residual petroleum. It has been shown that polycyclic aromatic hydrocarbons require metabolic activation before they can act as mutagens or carcinogens. This metabolic activation results from interaction with microsomal enzymes present in many body cells, yielding reactive epoxides which react with DNA and produce mutations in the count frame shift or participate in covalent bounding. While opinions differ regarding the relative role of these processes in mutagenesis, considerable evidence exists which links mutagenesis and carcinogenesis. Metabolites of the polycyclic aromatic hydrocarbons which are carcinogenic are usually mutagenic, which supports the hypothesis that damage to chromosomes plays an important role in carcinogenesis. These facts open the possibility to monitoring the spread of carcinogenic substances in the biosphere by relatively simple tests whose endpoint is mutagenesis. PMID:446450

Pashin, Y V; Bakhitova, L M

1979-06-01

133

Energy sources of polycyclic aromatic hydrocarbons. [Carcinogenicity of PAHs  

SciTech Connect

Combustion is the predominant end-process by which fossil fuels are converted to energy. Combustion, particularly when inefficient, is also the primary technological source of polycyclic aromatic hydrocarbons (PAHs) released into the environment. The need for liquid fuels to supply the transportation industry and for nonpolluting fuels for heat and power generation provide the incentive to commercialize processes to convert coal to substitute natural gas and oil. These processes represent a potentially massive new source of environmental PAHs. Insuring an adequate supply of energy with minimum impact on the environment and on health is one of the most important, urgent, and challenging goals currently facing science and technology. Polycyclic aromatic hydrocarbon related carcinogenesis is among the most important of possible occupational- and environmental-health impacts of much of the current and projected national energy base. An understanding of the relationship of polycyclic aromatic hydrocarbons (PAHs) to human cancer and a continued surveillance of energy sources for PAH content are necessary to minimize this impact.

Guerin, M. R.

1977-01-01

134

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

135

INDOOR AIR ASSESSMENT - INDOOR CONCENTRATIONS OF ENVIRONMENTAL CARCINOGENS  

EPA Science Inventory

In this report, indoor concentration data are presented for the following general categories of air pollutants: adon-222, environmental tobacco smoke (ETS), asbestos, gas phase organic compounds, formaldehyde, polycyclic aromatic hydrocarbons (PAN), pesticides, and inorganic comp...

136

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

EPA Science Inventory

The objective of this project was to develop a generic sampling and analytical methodology to characterize the polynuclear aromatic hydrocarbon (PAH) concentrations in air within various microenvironments. The following three studies were performed: evaluation of analytical metho...

137

Occurrence of chlorinated polynuclear aromatic hydrocarbons in tap water  

SciTech Connect

Organic compounds in tap waters were extracted by a modified continuous liquid-liquid extractor and analyzed by computerized gas chromatography/mass spectrometry using a fused silica capillary column. The results indicate the presence of monochlorinated derivatives of naphthalene, dibenzofuran, fluorene, fluorenone, phenanthrene, and fluoranthene and dichlorinated derivatives of naphthalene, phenanthrene, and fluoranthene. The parent polynuclear aromatic hydrocarbons (PAHs) and their oxygenated derivatives such as fluorenone and anthraquinone were also found. It was demonstrated that chlorinated PAHs (Cl-PAHs) were really present in tap waters at 10/sup -1/-10/sup -2/ ng/L levels.

Shiraishi, H.; Pilkington, N.H.; Otsuki, A.; Fuwa, K.

1985-07-01

138

Polycyclic aromatic hydrocarbon-DNA adduct formation in prostate carcinogenesis  

PubMed Central

The evidence for polycyclic aromatic hydrocarbons (PAH) playing a role in prostate carcinogenesis comes mainly from associations between reported PAH exposures and prostate cancer in epidemiologic studies. Associations between prostate cancer and DNA repair genotypes and phenotypes have also been reported, lending further credence to a PAH-induced carcinogenesis pathway in prostate cancer. Recent work that demonstrates the human prostate has metabolic enzyme activity necessary for PAH activation and will form DNA adducts upon exposure to PAH further supports PAH carcinogenesis. We have demonstrated the presence of PAH-DNA adducts in prostate cancer cases, but further validation of this biomarker as a carcinogenic agent in human prostate is needed. PMID:16154258

Rybicki, Benjamin A.; Nock, Nora L.; Savera, Adnan T.; Tang, Deliang; Rundle, Andrew

2006-01-01

139

Capillary and microchip electrophoretic analysis of polycyclic aromatic hydrocarbons.  

PubMed

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous contaminants which can reach the environment and food in different ways. Because of their high toxicity, two international regulatory institutions, the US Environmental Protection Agency and the European Food Safety Authority, have classified PAHs as priority pollutants, generating an important demand for the detection and identification of PAHs. Thus, sensitive, fast, and cheap methods for the analysis of PAHs in environmental and food samples are urgently needed. Within this context, electrophoresis, in capillary or microchip format, displays attractive features. This review presents and critically discusses the published literature on the different approaches to capillary and microchip electrophoresis analysis of PAHs. PMID:25542576

Ferey, Ludivine; Delaunay, Nathalie

2015-04-01

140

Reactivity of polycyclic aromatic hydrocarbons adsorbed on soot particles  

NASA Astrophysics Data System (ADS)

Polycyclic aromatic hydrocarbons (PAH) adsorbed on soot particles do not react significantly when exposed to ambient laboratory atmospheres for periods of up to 230 days or to air containing 5 ppm SO 2 for 99 days. Exposure to air containing 10 ppm NO x gave decreasing recoveries of PAH with time. It has been established that the reactivity of PAH under these conditions is anthanthrene > benzo(a)pyrene > benzo(ghi)perylene > benz(a)anthracene > pyrene > benzo(e)pyrene > chrysene > fluoranthene > phenanthrene ~ coronene. Evidence is presented which indicates that even in the absence of photolysis or ozone that PAH in ambient NO x polluted air can be converted to nitro derivatives. These nitration reactions will reduce the carcinogenic content of polluted air, as the 6-nitro-benzo(a)pyrene, 7-nitrobenz(a)anthracene and nitrochrysene derivatives that are formed, in contrast to the parent hydrocarbons, are non-carcinogenic.

Butler, J. D.; Crossley, P.

141

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

142

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

143

Polycyclic Aromatic Hydrocarbons as Plausible Prebiotic Membrane Components  

NASA Astrophysics Data System (ADS)

Aromatic molecules delivered to the young Earth during the heavy bombardment phase in the early history of our solar system were likely to be among the most abundant and stable organic compounds available. The Aromatic World hypothesis suggests that aromatic molecules might function as container elements, energy transduction elements and templating genetic components for early life forms. To investigate the possible role of aromatic molecules as container elements, we incorporated different polycyclic aromatic hydrocarbons (PAH) in the membranes of fatty acid vesicles. The goal was to determine whether PAH could function as a stabilizing agent, similar to the role that cholesterol plays in membranes today. We studied vesicle size distribution, critical vesicle concentration and permeability of the bilayers using C6-C10 fatty acids mixed with amphiphilic PAH derivatives such as 1-hydroxypyrene, 9-anthracene carboxylic acid and 1,4 chrysene quinone. Dynamic Light Scattering (DLS) spectroscopy was used to measure the size distribution of vesicles and incorporation of PAH species was established by phase-contrast and epifluorescence microscopy. We employed conductimetric titration to determine the minimal concentration at which fatty acids could form stable vesicles in the presence of PAHs. We found that oxidized PAH derivatives can be incorporated into decanoic acid (DA) vesicle bilayers in mole ratios up to 1:10 (PAH:DA). Vesicle size distribution and critical vesicle concentration were largely unaffected by PAH incorporation, but 1-hydroxypyrene and 9-anthracene carboxylic acid lowered the permeability of fatty acid bilayers to small solutes up to 4-fold. These data represent the first indication of a cholesterol-like stabilizing effect of oxidized PAH derivatives in a simulated prebiotic membrane.

Groen, Joost; Deamer, David W.; Kros, Alexander; Ehrenfreund, Pascale

2012-08-01

144

Activity of Arylsulphatase in Soil Contaminated with Polycyclic Aromatic Hydrocarbons.  

PubMed

An experiment has been performed to determine the activity of arylsulphatase in soil submitted to pressure of four polycyclic aromatic hydrocarbons: naphthalene, phenanthrene, anthracene, and pyrene, in the amount of: 0, 1,000, 2,000, and 4,000 mg kg(-1) dm of soil. Soil samples were also applied some organic substances, such as: cellulose, sucrose, and compost, in the amount of 0 and 9 g kg(-1) dm of soil. The experiment was run under laboratory conditions. It was established on soil which belonged to loamy sand. The soil resistance (RS) and resilience (RL) indices were computed. It has been discovered that the PAHs stimulated arylsulphatase activity, with anthracene raising the activity of the enzyme to the highest degree. The activity of arysulphatase depended significantly on the dose of a PAH, duration of pressure, and type of organic substances added to soil. The highest resistance (RS) was determined in soil exposed to phenanthrene, and the lowest one-in soil polluted with pyrene. Low values of the RL index prove that polycyclic aromatic hydrocarbons cause lasting disorders in the activity of arylsulphatase. PMID:25221368

Lipi?ska, Aneta; Kucharski, Jan; Wyszkowska, Jadwiga

2014-01-01

145

Polycyclic aromatic hydrocarbons (PAHs) in livers of California sea otters.  

PubMed

Concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were measured in livers of 81 adult female sea otters collected along the California coast in 1992-2002. Concentrations of summation operatorPAHs in livers of sea otters were in the range of 588-17400ng/g lipid wt (mean: 3880ng/g, lipid wt). On a wet weight basis, the concentrations ranged from 17 to 1430ng/g (mean: 146ng/g). Overall, di- and tri-cyclic aromatic hydrocarbons, namely, naphthalene, fluorene, phenanthrene/anthracene, and acenaphthylene, were the predominant compounds found in the livers. Although petroleum-related sources appear to be the major contributors to PAH exposure in sea otters, exposure sources varied by geographical sub-regions. Dibenz[a,h]anthracene was found to comprise a significant proportion of the summation operatorPAH concentrations in sea otters from the northern sub-region of the study area. No significant difference existed in the concentrations of summation operatorPAHs among sea otters that died from infectious diseases, emaciation, and noninfectious causes. Concentrations of summation operatorPAHs in livers of sea otters decreased significantly from 1992 to 2002. Because of the rapid metabolism of PAHs in marine mammals such as sea otters, further studies examining the association of PAHs with health effects should determine hydroxylated metabolites in livers. PMID:18177687

Kannan, Kurunthachalam; Perrotta, Emily

2008-03-01

146

Interstellar polycylic aromatic hydrocarbons: from space to the laboratory  

NASA Astrophysics Data System (ADS)

Polycyclic Aromatic Hydrocarbons (PAHs) are the most likely carriers proposed to account for the Aromatic Infrared Bands observed in emission between 3.3 and 12.7 ?m, fulfilling both the chemical (presence of CC and CH aromatic bonds) and excitation constraints. We explain here how the emission spectrum of such species in astronomical environments can be modelled, to obtain for each infrared band both its intensity and its detailed profile. The PAH model suffers from the lack of identification of individual species. Two strategies are described here that are currently being used to progress in this identification process. The first idea is that features in the far IR are much more specific to the exact molecular identity. Therefore their search with the coming Herschel Space Observatory will provide an unambiguous way to identify these molecules through their IR emission. Second, a reflection on where interstellar PAHs come from and how they evolve due to environmental conditions (UV irradiation, gas and dust interactions) is also necessary to get more insights into the nature of interstellar PAH candidates. In particular, recent studies have emphasized a chemical link between PAHs and very small grains in photodissociation regions. Finally, we illustrate in this paper how progress in this field can only be attained by a synergy between astronomical observations, fundamental studies, both theoretical and experimental, and models.

Joblin, C.; Mulas, G.

147

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.

148

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...

149

Polycyclic aromatic hydrocarbons and nitropolycyclic aromatic hydrocarbons in urban air particulates and their relationship to emission sources in the Pan–Japan Sea countries  

Microsoft Academic Search

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

Ning Tang; Tetsuyuki Hattori; Rina Taga; Kazuhiko Igarashi; Xiaoyang Yang; Kenji Tamura; Hitoshi Kakimoto; Vasiliy F. Mishukov; Akira Toriba; Ryoichi Kizu; Kazuichi Hayakawa

2005-01-01

150

Assessment of Total Aromatic Hydrocarbons, Aliphatic and Polycyclic Aromatic Hydrocarbons in Surface Sediment and Fish from the Gulf of Tunis (Tunisia)  

Microsoft Academic Search

This investigation represents the extensive study of the spatial distribution and sources of hydrocarbons in the Gulf of Tunis. Sediments and fish were sampled within the open sea of the Gulf of Tunis during August 2004. All samples were extracted with organic solvents, separated by silica\\/alumina column chromatography, and analyzed by spectrofluorometry for the determination of total aromatic hydrocarbons (TAH)

Nadia Mzoughi; Lassaad Chouba; Gaëtane Lespes

2010-01-01

151

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

152

Adsorption and STM imaging of polycyclic aromatic hydrocarbons on graphene  

NASA Astrophysics Data System (ADS)

The structural characterization of polycyclic aromatic hydrocarbon molecules adsorbed on graphene is of fundamental importance in view of the use of graphene or graphene nanoribbons for electronic applications. Before reaching this point, one has to determine the structure of the adsorbed molecules. Here, we study the case of benzene, coronene, and hexabenzocoronene on a graphene layer. First, the adsorption properties of single molecules are calculated using first-principles calculations at the level of density functional theory. We benefit from a recent scheme, particularly adapted for weakly adsorbed molecules, allowing us to precisely calculate the van der Waals contribution. Then, scanning tunneling microscopy (STM) is used to produce images of self-assembled molecules comparing different theoretical approaches to experimental observations. Finally, we consider the imaging of isolated molecules, and we show how the STM tip influences the molecule position by soft mechanical interaction during the scanning process.

Dappe, Y. J.; Andersen, M.; Balog, R.; Hornekær, L.; Bouju, X.

2015-01-01

153

Distribution of polycyclic aromatic hydrocarbons (PAH's) in marsh sediments, Iraq  

SciTech Connect

Recently there has been a growing concern in the release of harmful organics into the environment. Carcinogenic polycyclic aromatic hydrocarbons (PAH's) are a class of compounds of interset due to their possible harmful effects to man as well as organisms. Anthropogenic PAH's may reach aquatic environment as a result of both industrial and domestic effluents, deposition of airborne particles, surface runoff and oil spillage. Having a relatively low water solubility and high affinity to sorb to the suspended particulate matter, most of the PAH's introduced to the aquatic environment tend to accumulate in bottom sediments. Sedimentary PAH's may thus provide a record of the input and history of these pollutants. Consequently, the distribution of PAH's in aquatic sediments have received considerable attention. The purpose of the present work was to establish the distribution of PAH's in the sediments of the marsh region located in southern Iraq.

Al-Saad, H.T.; Al-Timari, A.A. (Univ. of Basrah (Iraq))

1989-12-01

154

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

155

REMPI detection of volatile aromatic hydrocarbons in ambient air  

NASA Astrophysics Data System (ADS)

Volatile aromatic hydrocarbons such as benzene, toluene, ethylbenzene, and xylenes (BTEX), and styrene, aniline, and phenol can be directly and sensitively detected in ambient air by resonance-enhanced multiphoton ionization (REMPI) spectroscopy. The REMPI spectra closely resemble conventional absorbance spectra, but the REMPI technique is far more sensitive. Detection limits for directly focused tunable laser light into the ionization cell are less than 10 ppbv for BTEX and less than 1 ppbv for styrene, aniline, and phenol. Benzene in aqueous solution was remotely detected down to concentrations at the (mu) g/L level by a headspace analysis in which light was delivered to the ionization cell over a 20-meter long optical fiber.

Swenson, Orven F.; Gillispie, Gregory D.

1996-11-01

156

Factors affecting airborne monocyclic aromatic hydrocarbon uptake by plants  

NASA Astrophysics Data System (ADS)

Three factors influencing foliar uptake of monocyclic aromatic hydrocarbons (MAHs; benzene, toluene, ethylbenzene, xylenes) in situ were investigated. The first factor, the plant species, was found to determine absorption pattern and concentrations. Secondly, time variation studies showed that response of leaf concentrations to small changes in air concentrations only occurs after several days or weeks, whereas adaptation to a much higher level of air pollution takes several months. Thirdly, MAH leaf concentrations were observed to be dependent on mean air pollution at the sampling site. Bioconcentration factors BCF vs (g m -3 of wet leaf/g m -3 of air) for MAHs in Pseudotsuga menziesii (Mirb.) Franco leaves were determined to range from 2.7 × 10 4 to 4.7 × 10 5.

Keymeulen, Regine; Schamp, Niceas; Van Langenhove, Herman

157

Amperometric Immunosensors for screening of Polycyclic Aromatic Hydrocarbons in water  

NASA Astrophysics Data System (ADS)

An amperometric immunosensor with low limit detection was developed for the screening of polycyclic aromatic hydrocarbons (PAHs) in water. The system was based on detecting the specific substance using an immunological reaction by measuring the chemical responses to specific antibodies. An integrated biochip with a three electrode system was fabricated. Gold was used as the working electrode with platinum was used as the counter electrode. A modified Ag/AgCl reference electrode was employed to enhance the stability of the immunosensors. Indirect competition enzyme-linked immunosorbent assay (ELISA) was carried out within the electrode using alkaline phosphatase (AP) as the labelled-enzyme. The system shows acceptable reproducibility and good stability. The immunosensor exhibited a wide linear response to PAHs. A limit of detection for this sensor was in the range of 1 to 10 ng ml-1 in aqueous sample.

Ahmad, A.; Paschero, A.; Moore, E.

2011-08-01

158

REMPI detection of volatile aromatic hydrocarbons in ambient air  

SciTech Connect

Volatile aromatic hydrocarbons such as benzene, toluene, ethylbenzene, and xylenes (BTEX), and styrene, aniline, and phenol can be directly and sensitively detected in ambient air by resonance-enhanced multiphoton ionization (REMPI) spectroscopy. The REMPI spectra closely resemble conventional absorbance spectra, but the REMPI technique is far more sensitive. Detection limits for directly focused tunable laser light into the ionization cell are less than 10 ppbv for BTEX and less than 1 ppbv for styrene, aniline, and phenol. Benzene in aqueous solution was remotely detected down to concentrations at the {micro}g/L level by a headspace analysis in which light was delivered to the ionization cell over a 20-meter long optical fiber.

Swenson, O.; Gillispie, G.D. [North Dakota State Univ., Fargo, ND (United States). Dept. of Chemistry

1996-12-31

159

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

160

Spectroscopic properties of some derivatives of polycyclic aromatic hydrocarbons.  

PubMed

The aim of this paper is to provide a general picture of the spectral characteristics of some polycyclic aromatic hydrocarbon (PAH) derivatives. A great deal of data concerning PAHs has been reported in the literature, but there is lack of comprehensiveness about important parameters in the same experimental conditions for their nitro (NO(2)) and amino (NH(2)) derivatives such as absorption and emission characteristics. Thus, important parameters such as the molar extinction coefficient, absorption maxima, fluorescence maxima, and fluorescence quantum yield are reported here. The efficiencies of the reduction of NO(2)-PAHs to their corresponding amino compounds were also verified by means of high-performance liquid chromatography (HPLC). This class of derivatives represents one of the most toxic groups of carcinogenic substances and therefore the data reported here should be useful for toxicological research. PMID:19007465

Catalfo, Alfio; Serrentino, Maria Elisabetta; Librando, Vito; Perrini, Giancarlo; de Guidi, Guido

2008-11-01

161

Polycyclic aromatic hydrocarbons in Chinese surface soil: occurrence and distribution.  

PubMed

In this study, 16 polycyclic aromatic hydrocarbons (PAHs) were analyzed in 157 concurrently collected soil samples in 2005 over China. Higher concentration of ?16PAHs was found in urban soil, followed by rural and background soil. The results indicated that PAHs in Chinese surface soil showed a primary distribution pattern, which was confirmed by the positive correlation with emission inventory. Based on the results of literature over the past 10 years (2004-2013) in China, the spatial distribution of PAHs in urban and rural soil was established. An obvious geographical distribution with PAH concentration was found, as higher in Eastern China and lower in Middle and Western China. Furthermore, PAH pollution in Chinese riverbank soil was summarized and showed higher levels, indicating their potential sources from polluted rivers. According to our knowledge, this is the first time to comprehensively study the PAH pollution status in Chinese surface soil on the national scale based on monitoring results. PMID:25277713

Ma, Wan-Li; Liu, Li-Yan; Tian, Chong-Guo; Qi, Hong; Jia, Hong-Liang; Song, Wei-Wei; Li, Yi-Fan

2015-03-01

162

Particulate polycyclic aromatic hydrocarbons and n-alkanes in recycled paper processing operations.  

PubMed

The aliphatic and polycyclic aromatic fractions of dust collected in the vicinity of recycled paper processing operations were analyzed using gas chromatography/mass spectrometry. Total measured dust concentration (up to 8.73+/-2.02 mg/m3) fluctuated substantially in the different steps of paper manufacture. This was attributed to the type of the operation such as, the release of fibers and particles during paper cutting and the use of reactive chemicals and excessive water under high temperature and pressure during the bleaching and the water rinsing/drying step. Particulate polycyclic aromatic hydrocarbons (PAHs) (from fluorene to benzo[ghi]perylene with mean concentrations from 3.8+/-0.5 to 41.4+/-0.4 ng/m3) and the unresolved mixture of branched, cyclic and unsaturated hydrocarbons (UCM) were measured in all samples while, n-alkanes from n-C20 to n-C27, were only observed in cutting and packaging areas (from 180.6+/-18.9 to 4297.9+/-794.9 ng/m3). The profile of occupational PAHs in bleaching and treatment of contaminated recycled raw paper was comparable to that observed for anthropogenic activities. The values of molecular diagnostic ratios indicated the contribution of oil residues and emissions from worklifts and other equipment used for pulp and paper handling. Total benzo[a]pyrene-equivalent (BaP) concentrations of particulate PAHs (varied from 323 up to 1104 pg/m3), provided evidence that workers were exposed to high quantities of PAHs as compared with exposures to urban air and other indoor settings, posing long-term threat to their health. PMID:16704897

Chalbot, Marie-Cecile; Vei, Ino; Lykoudis, Spyros; Kavouras, Ilias G

2006-09-21

163

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

164

Thermochemical Properties and Phase Behavior of Halogenated Polycyclic Aromatic Hydrocarbons  

PubMed Central

Knowledge of vapor pressure of organic pollutants is essential in predicting their fate and transport in the environment. In the present study, the vapor pressures of 12 halogenated polycyclic aromatic compounds (PACs), i.e. 9-chlorofluorene, 2,7-dichlorofluorene, 2-bromofluorene, 9-bromofluorene, 2,7-dibromofluorene, 2-bromoanthracene, 9-chlorophenanthrene, 9-bromophenanthrene, 9,10-dibromophenanthrene, 1-chloropyrene, 7-bromobenz[a]anthracene and 6,12-dibromochrysene, were measured using the Knudsen effusion method over the temperature range of 301 to 464 K. Enthalpies and entropies of sublimation of these compounds were determined via application of the Clausius–Clapeyron equation. The data were also compared with earlier published literature values to study the influence of halogen substitution on vapor pressure of PACs. As expected, the halogen substitution decreases vapor pressure compared to parent compounds, but does not necessarily increase the enthalpy of sublimation. Moreover, the decrease of vapor pressure also depends on the substitution position and the substituted halogen, and the di-substitution of chlorine and/or bromine decreases the vapor pressure compared to single halogen substituted polycyclic aromatic hydrocarbons. Additionally, the enthalpy of fusion and melting temperature of these 12 PACs were determined using differential scanning calorimetry and melting point analysis. PMID:22139714

Suuberg, Eric M.

2013-01-01

165

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

166

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

167

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

168

Large Abundances of Polycyclic Aromatic Hydrocarbons in Titan's Upper Atmosphere  

NASA Technical Reports Server (NTRS)

In this paper, we analyze the strong unidentified emission near 3.28 micron 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 micron. 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) × 10(exp 4) particles / cubic cm. 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 sq. nm; 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.; Dinelli, B. M.; Adriani, A.; Funke, B.; Garcia-Comas, M.; Moriconi, M. L.; D'Aversa, E.; Boersma, C.; Allamandola, L. J.

2013-01-01

169

Development of a groundwater biobarrier for the removal of polycyclic aromatic hydrocarbons, BTEX, and heterocyclic hydrocarbons.  

PubMed

A full scale funnel-and-gate biobarrier has been developed for the removal of tar oil pollutants at an abandoned tar factory site near the city of Offenbach, Germany. Laboratory and on-site column studies were done to determine the operation parameters for microbiological clean-up of the groundwater polluted with 12,000 microg/L mono- aromatic hydrocarbons such as benzene and the xylenes, 4,800 microg/L polycyclic aromatic hydrocarbons such as naphthalene and acenaphthene, and 4,700 microg/L heterocyclic aromatic hydrocarbons such as benzofuran and benzothiophene. In the laboratory study, a residence time of approx. 70 h proved to be sufficient for aerobic pollutant biodegradation. Up to 180 mg/L H(2)O(2) were added and did not lead to any toxic effects to the degrading bacteria. The feasibility of the concept was confirmed in an on-site pilot study performed with a sedimentation tank (removal of ferric iron) and two bioreactors. In the bioreactors, >99.3% of the pollutants were degraded. Biodegradation activity corresponded to a significant increase in numbers of pollutant degrading bacteria. In the bioreactors, a fast dissociation of H(2)O(2) was observed resulting in losses of oxygen and temporary gas clogging. Therefore, a repeated addition of moderate concentrations of H(2)O(2) proved to be more favourable than the addition of high concentrations at a single dosing port. The full scale biobarrier consists of three separated bioreactors thus enabling extended control and access to the reactors. The operation of the funnel-and-gate biobarrier started in April 2007, and represents the first biological permeable reactive barrier with extended control (EC-PRB) in Germany. PMID:18957746

Tiehm, A; Müller, A; Alt, S; Jacob, H; Schad, H; Weingran, C

2008-01-01

170

Reduction of Aromatic Hydrocarbons by Zero-Valent Iron and Palladium Catalyst  

SciTech Connect

Permeable reactive barrier (PRB) is an alternative technology for soil and groundwater remediation. Zero valent iron, which is the most popular PRB material, is only applicable to halogenated aliphatic organics and some heavy metals. The objective of this study was to investigate reductive dechlorination of halogenated compounds and reduction of non-halogenated aromatic hydrocarbons using zero valent metals (ZVMs) and catalysts as reactive materials for PRBs. A group of small aromatic hydrocarbons such as monochlorophenols, phenol and benzene were readily reduced with palladium catalyst and zero valent iron. Poly-aromatic hydrocarbons (PAHs) were also tested with the catalysts and zero valent metal combinations. The aromatic rings were reduced and partly reduced PAHs were found as the daughter compounds. The current study demonstrates reduction of aromatic compounds by ZVMs and modified catalysts and implicates that PRB is applicable not only for halogenated organic compounds but nonhalogenated aromatic compounds such as PAHs.

Kim, Young-Hun; Shin, Won Sik; Ko, Seok-Oh; Kim, Myung-Chul

2004-03-31

171

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

172

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

173

Emission of polycyclic aromatic hydrocarbons from gasohol and ethanol vehicles  

NASA Astrophysics Data System (ADS)

The exhaust emission of the polycyclic aromatic hydrocarbons (PAHs) considered toxic to human health were investigated on two spark ignition light duty vehicles, one being gasohol (Gasohol, in Brazil, is the generic denomination for mixtures of pure gasoline plus 20-25% of anhydrous ethyl alcohol fuel (AEAF).)-fuelled and the other a flexible-fuel vehicle fuelled with hydrated ethanol. The influence of fuel type and quality, aged lubricant oil type and use of fuel additives on the formation of these compounds was tested using standardized tests identical to US FTP-75 cycle. PAH sampling and chemical analysis followed the basic recommendations of method TO-13 (United States. Environmental Protection Agency, 1999. Compendium Method TO-13A - Determination of polycyclic Aromatic hydrocarbons (PAH) in Ambient Air Using Gas Chromatography/Mass Spectrometry (CG/MS). Center for environmental research information, Cincinnati, p. 78), with the necessary modification for this particular application. Results showed that the total PAH emission factor varied from 41.9 ?g km -1 to 612 ?g km -1 in the gasohol vehicle, and from 11.7 ?g km -1 to 27.4 ?g km -1 in the ethanol-fuelled vehicle, a significant difference in favor of the ethanol vehicle. Generally, emission of light molecular weight PAHs was predominant, while high molecular weights PAHs were not detected. In terms of benzo( a)pyrene toxicity equivalence, emission factors varied from 0.00984 ?g TEQ km -1 to 4.61 ?g TEQ km -1 for the gasohol vehicle and from 0.0117 ?g TEQ km -1 to 0.0218 ?g TEQ km -1 in the ethanol vehicle. For the gasohol vehicle, results showed that the use of fuel additive causes a significant increase in the emission of naphthalene and phenanthrene at a confidence level of 90% or higher; the use of rubber solvent on gasohol showed a reduction in the emission of naphthalene and phenanthrene at the same confidence level; the use of synthetic oil instead of mineral oil also contributed significantly to a decrease in the emission of naphthalene and fluorene. In relation to the ethanol vehicle, the same factors were tested and showed no statistically significant influence on PAH emission.

de Abrantes, Rui; Vicente de Assunção, João; Pesquero, Célia Regina; Bruns, Roy Edward; Nóbrega, Raimundo Paiva

174

COMPUTER AUTOMATED EVALUATION OF MUTAGENICITY AND CARCINOGENICITY OF SELECTED POLYCYCLIC AROMATIC HYDROCARBONS  

EPA Science Inventory

The mechanisms by which polycyclic aromatic hydrocarbons (PAHs) induce mutations and cancer have been the subject of considerable attention for several years. arious theoretical and experimental models have been advanced the effects of structural variations on mutagenicity and ca...

175

Molecular catalytic hydrogenation of aromatic hydrocarbons and hydrotreating of coal liquids.  

SciTech Connect

This report presents the results of research on the development of new catalytic pathways for the hydrogenation of multiring aromatic hydrocarbons and the hydrotreating of coal liquids at The University of Chicago under DOE Contract No. DE-AC22-91PC91056. The work, which is described in three parts, is primarily concerned with the research on the development of new catalytic systems for the hydrogenation of aromatic hydrocarbons and for the improvement of the quality of coal liquids by the addition of dihydrogen. Part A discusses the activation of dihydrogen by very basic molecular reagents to form adducts that can facilitate the reduction of multiring aromatic hydrocarbons. Part B examines the hydrotreating of coal liquids catalyzed by the same base-activated dihydrogen complexes. Part C concerns studies of molecular organometallic catalysts for the hydrogenation of monocyclic aromatic hydrocarbons under mild conditions.

Yang, Shiyong; Stock, L.M.

1996-05-01

176

Modeling the Role of Alkanes, Polycyclic Aromatic Hydrocarbons, and Their Oligomers in Secondary Organic Aerosol Formation  

EPA Science Inventory

A computationally efficient method to treat secondary organic aerosol (SOA) from various length and structure alkanes as well as SOA from polycyclic aromatic hydrocarbons (PAHs) is implemented in the Community Multiscale Air Quality (CMAQ) model to predict aerosol concentrations ...

177

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...

178

CHEMICAL ACTIVATION OF NON-MUTAGENIC NITRATED POLYCYCLIC AROMATIC HYDROCARBONS TO MUTAGENS  

EPA Science Inventory

Nitrated polycyclic aromatic hydrocarbons, including carcinogens, may be non-mutagenic in microorganisms because bacterial nitroreductases are unable to reduce their nitro function to proximate mutagenic hydroxylamines. The reduction of the nitro moiety can be accomplished chemic...

179

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...

180

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

181

METHODOLOGY FOR DETERMINATION OF POLYCYCLIC AROMATIC HYDROCARBONS AND OTHER SEMIVOLATILE ORGANIC COMPOUNDS IN HOUSE DUST  

EPA Science Inventory

Analytical methods were validated to determine polycyclic aromatic hydrocarbons (PAH) and other semivolatile organic compounds in house dust. e also examined the storage stability of three potential markers (solanesol, nicotine, and continine) for particulate-phase environmental ...

182

COMBINED CHEMICAL AND BIOLOGICAL OXIDATION OF SLURRY PHASE POLYCYCLIC AROMATIC HYDROCARBONS  

EPA Science Inventory

Bioslurry treatment of polycyclic aromatic hydrocarbon (PAH)-impacted soils was demonstrated under the Superfund Innovative Technologies Evaluation (SITE)/Emerging Technologies Program (ETD) as an extension of research previously funded by IT Corporation (IT) (Brown and Sanseveri...

183

ANALYSIS OF POLYNUCLEAR AROMATIC HYDROCARBONS IN PARTICULATE MATTER BY LUMINESCENCE TECHNIQUES  

EPA Science Inventory

Fluorescence, phosphorescence, and heavy-metal activated room temperature phosphorescence spectra were obtained for ten polycyclic aromatic hydrocarbon (PAH) reference compounds individually and in mixtures on quartz plates and particulate matter. The results indicate that multic...

184

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...

185

MULTISUBSTRATE BIODEGRADATION KINETICS FOR BINARY AND COMPLEX MIXTURES OF POLYCYCLIC AROMATIC HYDROCARBONS  

EPA Science Inventory

Biodegradation kinetics were studied for binary and complex mixtures of nine polycyclic aromatic hydrocarbons (PAHs): naphthalene, 1-methylnaphthalene, 2-methylnaphthalene, 2-ethylnaphthalene, phenanthrene, anthracene, pyrene, fluorene and fluoranthene. Discrepancies between the ...

186

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...

187

Polycyclic aromatic hydrocarbons and petroleum biomarkers in São Sebastião Channel, Brazil: Assessment of petroleum contamination  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs) and non-aromatic hydrocarbons (NAHs), including n-alkanes, isoprenoids and petroleum biomarkers (terpanes, hopanes, steranes and diasteranes), were quantified by gas chromatography with flame ionization and mass spectrometer detectors in sediment samples collected from the São Sebastião Channel (SSC), Brazil, where the largest Brazilian maritime petroleum terminal is located. The concentrations of total PAHs, total n-alkanes and petroleum

Denis A. M. da Silva; Márcia C. Bícego

2010-01-01

188

Microwave assisted extraction of polycyclic aromatic hydrocarbons from atmospheric particulate samples  

Microsoft Academic Search

For several years, microwave assisted extraction (MAE) was applied to extract organic compounds such as polycyclic aromatic\\u000a hydrocarbons (PAHs), polychlorinated biphenyls, etc., from soils, sediments and standard reference materials. Very few authors\\u000a applied this methodology for the extraction of PAHs from atmospheric particulate matter. In the present study, MAE of polycyclic\\u000a aromatic hydrocarbons with hexane\\/acetone (1?:?1) from real atmospheric particulate

M. Piñeiro-Iglesias; P. López-Mahía; E. Vázquez-Blanco; S. Muniategui-Lorenzo; D. Prada-Rodríguez; E. Fernández-Fernández

2000-01-01

189

Direct Determination of the Phase Distributions of Semi-VolatilePolycyclic Aromatic Hydrocarbons Using Annular Denuders  

SciTech Connect

An annular denuder-based sampler, here called the integrated organic vapor/particle sampler (IOVPS), has been developed for direct determination of both gas and particulate semi-volatile organic species. The IOVPS uses a cyclone inlet for removal of particles greater than 2.5 micrometers 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. For example, the results obtained with the IOVPS indicate that the volatilization artifact ('blow-off') from particulate PAH collected in indoor laboratory room air with a conventional filter-sorbent bed sampler at face velocity of 33 cm sec-1 led to three-fold underestimation of the particulate fractions of phenanthrene, pyrene and chrysene. Phase distributions for PAH in ETS are also reported here.

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

1994-06-01

190

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

191

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 compouns 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, Eddie G. (Richland, WA); Elliott, Douglas C. (Richland, WA)

1993-01-01

192

Atmospheric transport and outflow of polycyclic aromatic hydrocarbons from China  

SciTech Connect

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 Nino/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. 38 refs., 4 figs.

Chang Lang; Shu Tao; Wenxin Liu; Yanxu Zhang; Staci Simonich [Peking University, Beijing (China). Laboratory for Earth Surface Processes, College of Environmental Sciences

2008-07-15

193

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

194

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

195

Polycyclic aromatic hydrocarbon ions and the diffuse interstellar bands  

NASA Technical Reports Server (NTRS)

Neutral naphthalene (C10H8), phenanthrene (C14H10), and pyrene (C16H10) absorb strongly in the ultraviolet and may contribute to the extinction curve. High abundances are required to produce detectable structures. The cations of these Polycyclic Aromatic Hydrocarbons (PAHs) absorb in the visible. C10H8(+) has 12 discrete absorption bands which fall between 6800 and 5000 A. The strongest band at 6741 A falls close to the weak 6742 A diffuse interstellar band (DIB). Five other weaker bands also match DIBs. The possibility that C10H8(+) is responsible for some of the DIBs can be tested by searching for new DIBS at 6520, 6151, and 5965 A, other moderately strong naphthalene cation band positions. If C10H8(+) is indeed responsible for the 6742 A feature, it accounts for 0.3% of the cosmic carbon. The spectrum of C16H10(+) is dominated by a strong band at 4435 A in an Ar matrix and 4395 A in a Ne matrix, a position which falls very close to the strongest DIB, that at 4430 A. If C16H10(+), or a closely related pyrene-like ion is indeed responsible for the 4430 A feature, it accounts for 0.2% of the cosmic carbon. We also report an intense, very broad UV-to-visible continuum which is associated with both ions and could explain how PAHs convert interstellar UV and visible radiation into IR.

Salama, F.; Allamandola, L. J.

1995-01-01

196

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

197

Polycyclic aromatic hydrocarbons in Bangladeshi vegetables and fruits.  

PubMed

Polycyclic aromatic hydrocarbons (PAHs) occur as contaminants in different types of food predominantly from environmental pollution, food packaging and food processing and the levels found depend on the source of the contamination. PAHs emissions from automobile traffic and industry activities were shown to influence the PAHs levels and profiles in vegetables and fruits grown nearby. The present study was carried out to determine the levels of PAHs in samples of tomato, cabbage and apple, collected from six different places of urban and rural areas of plantation in Dhaka city. Eight PAHs listed in the priority pollutant of US Environment Protection Agency and regarded as carcinogens were analyzed in this study. The analytical method involved saponification with methanolic KOH, liquid-liquid extraction with cyclohexane, clean-up on silica gel column and determination by Gas chromatography and mass spectrometry. The mean levels of total PAHs were 9.50 ?g/kg in tomato, 8.86 ?g/kg in cabbage and 4.05 ?g/kg in apple. Of the carcinogenic PAHs, benzo(a)anthracene was the most representative, being found in 89% of all samples analysed. Chrysene was not detected in any sample. PMID:21056073

Hossain, M Amzad; Hoque, Mohammad Zahirul

2011-01-01

198

Fullerenes, fulleranes and polycyclic aromatic hydrocarbons in the Allende meteorite  

NASA Technical Reports Server (NTRS)

In this paper, we confirm our earlier observations of fullerenes (C60 and C70) in the Allende meteorite (Becker et al., 1994a, 1995). Fullerene C60 was also detected in two separate C-rich (approximately 0.5-1.0%) dark inclusions (Heymann et al., 1987) that were hand picked from the Allende sample. The amounts of C60 detected were approximately 5 and approximately 10 ppb, respectively, which is considerably less than what was detected in the Allende 15/21 sample (approximately 100 ppb; Becker et al., 1994a, 1995). This suggests that fullerenes are heterogeneously distributed in the meteorite. In addition, we present evidence for fulleranes, (C60Hx), detected in separate samples by laser desorption (reflectron) time-of-flight (TOF) mass spectrometry (LDMS). The LDMS spectra for the Allende extracts were remarkably similar to the spectra generated for the synthetic fullerane mixtures. Several fullerane products were synthesized using a Rh catalyst (Becker et al., 1993a) and separated using high-performance liquid chromatography (HPLC). Polycyclic aromatic hydrocarbons (PAHs) were also observed ppm levels) that included benzofluoranthene and corannulene, a cup-shaped molecule that has been proposed as a precursor molecule to the formation of fullerenes in the gas phase (Pope et al., 1993).

Becker, L.; Bunch, T. E.

1997-01-01

199

Measurement of polycyclic aromatic hydrocarbon (PAHs) in interplanetary dust particles  

NASA Technical Reports Server (NTRS)

We report here the first definitive measurements of specific organic molecules (polycyclic aromatic hydrocarbons (PAH's)) in interplanetary dust particles (IDP's). An improved version of the microbeam-two-step laser mass spectrometer was used for the analysis. Two IDP's gave similar mass spectra showing an abundance of PAH's. Control samples, including particles of probable terrestrial origin from the same stratospheric collector, gave either null results or quite different spectra. We conclude that the PAH's are probably indigenous to the IDP's and are not terrestrial contaminants. The instrument used to study the particles is a two-step laser mass spectrometer. Constituent neutral molecules of the sample are first desorbed with a pulsed infrared laser beam focussed to 40 micrometers. In the second step, PAH's in the desorbed plume are preferentially ionized by a pulsed UV laser beam. Resulting ions produced by resonant absorption are extracted into a reflectron time-of-flight mass spectrometer. This instrument has high spatial resolution, high ion transmission, unlimited mass range, and multichannel detection of all ion masses from a single laser shot.

Clemett, S. J.; Maechling, C. R.; Zare, R. N.; Swan, P. D.; Walker, R. M.

1993-01-01

200

Determination of selected nitropolycyclic aromatic hydrocarbons in water samples.  

PubMed

A new method for the analysis of selected nitropolycyclic aromatic hydrocarbons (NPAHs) at ultra-trace levels in water samples is proposed. Particulate NPAHs were collected on a GC glass fiber filter. Soluble NPAHs were collected on a C18 Empore disk. After simple clean-up and concentration of NPAHs in both phases, the NPAHs were analyzed using HPLC equipped with clean-up, reducer, concentration and chemiluminescence detection units. The proposed method showed good linear calibration curves with correlation coefficients (r(2)) ranging from 0.9954 to 0.9998. The limits of detection ranged from 0.013 to 0.15 nmol/L (soluble NPAHs) and from 0.01 to 0.13 nmol/L (particulate NPAHs) for 5 NPAHs [(9-nitroanthracene, 1-nitropyrene, 6-nitrochrysene (6-NC), 7-nitrobenz[a]anthracene and 6-nitrobenzo[a]pyrene] having 3 to 5 rings analyzed, when 1.5 L of water sample was used. The repeatability for soluble NPAHs ranged between 4.2 and 6.8% (n=5), while for particulate NPAHs, it varied between 2.2 and 2.8% (n=5). The proposed method successfully determined the above NPAHs expect 6-NC in river water samples, suggesting that this method is suitable for the ultra-trace analysis of NPAHs in water samples. PMID:24292788

Chondo, Yvonne; Li, Ying; Makino, Fumiya; Tang, Ning; Toriba, Akira; Kameda, Takayuki; Hayakawa, Kazuichi

2013-01-01

201

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

202

Evaluation of worker exposure to polycyclic aromatic hydrocarbons.  

PubMed

A sampling and analytical method was selected to determine the physical and chemical nature of worker exposure to polycyclic aromatic hydrocarbons (PAH). It consists of filter and sorbent tube sampling followed by benzene extraction and analysis of 12 different PAHs with a gas chromatograph connected to a mass spectrometer. This method has undergone extensive field trials. Sampling temperature, inorganic and organic interferences have an effect on the results as they do on the standard gravimetric method of benzene-solubles. A combination of the gravimetric method and the particulate and gaseous concentration profile of 12 PAHs is necessary to obtain an informative evaluation of worker exposure. This approach was used to demonstrate that workers in paving and roofing operations and on some worksites in the steel and silicon carbide industries show an exposure profile that suggests minimal health risk and is largely different from the exposure of workers in aluminum refineries, refractory brick laying and most other worksites in the silicon carbide industry. PMID:3687734

Lesage, J; Perrault, G; Durand, P

1987-09-01

203

DUSTY WINDS: EXTRAPLANAR POLYCYCLIC AROMATIC HYDROCARBON FEATURES OF NEARBY GALAXIES  

SciTech Connect

Recent observations have shown the presence of dust and molecular material in galactic winds, but relatively little is known about the distribution of these outflow components. To shed some light on this issue, we have used IRAC images from the Spitzer Space Telescope archive to investigate polycyclic aromatic hydrocarbon (PAH) emission from a sample of 16 local galaxies with known winds. Our focus on nearby sources (median distance 8.6 Mpc) has revealed detailed PAH structure in the winds and allowed us to measure extraplanar PAH emission. We have identified extraplanar PAH features on scales of {approx}0.8-6.0 kpc. We find a nearly linear correlation between the amount of extraplanar PAH emission and the total infrared flux, a proxy for star formation activity in the disk. Our results also indicate a correlation between the height of extraplanar PAH emission and star formation rate surface density, which supports the idea of a surface density threshold on the energy or momentum injection rate for producing detectable extraplanar wind material.

McCormick, Alexander; Veilleux, Sylvain [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Rupke, David S. N., E-mail: alexm@astro.umd.edu, E-mail: veilleux@astro.umd.edu, E-mail: rupked@rhodes.edu [Rhodes College, 2000 North Parkway, Memphis, TN 38112 (United States)

2013-09-10

204

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

205

Molecular simulation of polycyclic aromatic hydrocarbon sorption to black carbon.  

PubMed

Strong sorption of hydrophobic organic contaminants to soot or black carbon (BC) is an important environmental process limiting the bioremediation potential of contaminated soils and sediments. Reliable methods to predict BC sorption coefficients for organic contaminants are therefore required. A computer simulation based on molecular mechanics using force field methods has been applied in this study to calculate BC sorption coefficients of polycyclic aromatic hydrocarbons (PAHs). The free energy difference between PAHs dissolved in water and in water containing a model structure of BC was calculated by thermodynamic integration of Monte Carlo simulated energies of transfer. The free energies were calculated with a hypothetical reference state that has equal free energies in both phases and is therefore cancelled in the calculated free energy difference. The calculated sorption coefficient of phenanthrene (log K(BC) = 5.17 +/- 0.54 L/kg C), fluoranthene (6.33 +/- 0.64 L/kg C) and benzo[a]pyrene (7.38 +/- 0.36 L/kg C) corresponded very well to experimental values available in the literature. Furthermore, an average spacing distance of 3.73 A between PAHs and BC was determined that is only slightly lower than an experimentally determined value of 4.1 A. The method applied in this study enables the calculation of the extent of PAH sorption to a soot surface for which no experimental values are available nor data for related compounds as required in quantitative structure-activity relationships. PMID:19544190

Haftka, J J H; Parsons, J R; Govers, H A J

2009-01-01

206

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

207

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

208

Plant bioindicators for polycyclic aromatic hydrocarbon toxicity in aquatic microcosms  

SciTech Connect

Plant bioindicators are being developed to assess the effects of polycyclic aromatic hydrocarbons (PAHs) in experimental aquatic ecosystems. The approach is to develop and test biomarker assays that are specifically predictive of ecological events at the population and/or community levels of organization in artificial aquatic microcosms. PAH mixtures were introduced into a series of aquatic microcosms using the wood preservative creosote as a PAH source. The authors applied creosote at five dosage levels designed to simulate conductions observed at highly contaminated sites. The growth and biomass of phytoplankton, periphyton, and macrophytes were then measured throughout the growing season, and compared to one or more biomarker assays used to detect PAH contamination. Preliminary results using fluorescence induction on aquatic macrophytes suggest that PAHs can significantly inhibit photosynthesis at even modest concentrations 1--4 hours after exposure. This assay thus is not only a sensitive indicator of PAH exposure, but may also describe mechanisms of PAH toxicity that ultimately reduce biomass or population growth for aquatic plants in these microcosms.

Gensemer, R.W.; Solomon, K.R. [Univ. of Guelph, Ontario (Canada); Day, K.E.; Hodson, P.V.; Servos, M.R. [Canada Centre for Inland Waters, Burlington, Ontario (Canada); Greenberg, B.M. [Univ. of Waterloo, Ontario (Canada)

1994-12-31

209

Environmental exposure to polycyclic aromatic hydrocarbons in Czech Republic.  

PubMed

1 Objectives of this study were (1) to compare concentrations of individual polycyclic aromatic hydrocarbons (PAH) in air of polluted and nonpolluted area of Czech Republic during winter and summer periods and (2) to verify if urinary 1-hydroxypyrene (1-OHP), as supposed practical biological marker, permits the assessment of spacial and temporal variations in environmental PAH exposure. 2 The study population consisted of three groups: (1) a group of 22 physical exercise students who regularly train outside, from the university situated in a polluted town, spending 14 days in winter and 14 days in summer in 'non-polluted' mountains; (2) a control group of 22 residents from the town and (3) a control group of 18 residents from the mountains. 3 The total PAH concentrations (sum of 13 individual PAH) were 19.3 and 104.6 ng/m3 in town and in mountains, respectively, during summer and 86.6 and 261 ng/m3 during winter. 4 Median 1-OHP levels ranged between 0.03 and 0.13 mumol/mol creatinine for controls and between 0.04 and 0.12 mumol/mol creatinine for students. No relationship was found between pyrene levels in air and group means of urinary 1-OHP. Our results show that other factors (probably PAH in food) contribute in masking air pollution influence on urinary 1-OHP levels in subjects non-occupationally exposed to PAH. PMID:9363476

Vyskocil, A; Fiala, Z; Fialova, D; Krajak, V; Viau, C

1997-10-01

210

Photoinduced toxicity of sediment-bound polycyclic aromatic hydrocarbons  

SciTech Connect

Polycyclic aromatic hydrocarbons (PAHs) are known to be both mutagenic and toxic. Light, in particular UV irradiation, increases their toxicity. Since aquatic plants cannot avoid PAHs or light, they are at risk. However, the major loadings of PAHs are in sediment. In this study the authors examined the assimilation of both intact and photomodified labelled PAHs bound to a surrogate, sediment (sand) by the higher aquatic plant Lemna gibba L. G-3. They found that simulated solar radiation significantly promoted the release of PAHs from sand and their assimilation by Lemna, although assimilation from the solid phase was slower than for chemicals placed directly into the aqueous medium. Toxicity of PAHs bound to sand was then measured by exposing plants to the sand-chemical composite for 8 d. Plants were exposed to both visible and SSR light conditions during this period, and toxicity was measured as inhibition of growth, inhibition of photosynthesis (chlorophyll fluorescence induction) and chlorosis. All three endpoints indicated that PAHs bound to a sediment phase can express phototoxicity and that the effects are most strongly promoted by the UV region of the solar spectrum. The authors have now extended this work to probe the effects of UV-B and PAHs on chloroplast development, with the finding that both stresses inhibit development of the photosynthetic apparatus.

Greenberg, B.M.; Duxbury, C.L.; Marwood, C.A.; Huang, X.D.; Dixon, D.G. [Univ. of Waterloo, Ontario (Canada)

1994-12-31

211

Oxidation of polynuclear aromatic hydrocarbons in water. 1: Ozonation  

SciTech Connect

The oxidation of three polynuclear aromatic hydrocarbons (PAHs), fluorene, phenanthrene, and acenaphthene, in aqueous solution with ozone has been studied. The influence of hydroxyl radical inhibitors, pH, ozone partial pressure, and temperature was investigated. All the PAHs studied show high oxidation rates with ozone. The ozonation of fluorene seems to be due to both direct and hydroxyl radical reactions while for the rest of the PAHs the ozonation develops only through direct reactions with ozone. Rate constants for the direct reaction between these PAHs and ozone have also been calculated. The reactivity with ozone goes in the following order: fluorene < phenanthrene < acenaphthene. The contribution of radical reactions represents more than 90% in the ozonation of fluorene in most cases except in the presence of hydroxyl radical inhibitors. In a standard agitated reactor the kinetic regime of the absorption of ozone corresponds to a slow reaction in the case of fluorene and phenanthrene and to a fast reaction in the case of acenaphthene.

Beltran, F.J.; Encinar, J.M.; Rivas, J. [Univ. de Extremadura, Badajoz (Spain). Dept. de Ingenieria Quimica y Energetica; Ovejero, G. [Univ. Complutense, Madrid (Spain). Dept. de Ingenieria Quimica

1995-05-01

212

Role of iron catalyst on hydroconversion of aromatic hydrocarbons  

SciTech Connect

A symposium on iron-based catalysts for coal liquefaction was held at the 205th ACS National Meeting, and some of the papers have been published in Energy & Fuels. Reviews of the development of catalysts for coal liquefaction were also published in Journal of the Japan institute of Energy, and Ozaki reviewed the results of the studies of upgrading residual oils by means of thermal cracking and coking under reduced pressures, catalytic cracking over nickel ores and iron oxides, and hydrodesulfurization, as well as hydrodemetallization. We reported that catalysis of metallic iron and iron-sulfide catalysts were affected by the S/Fe ratio; the activity increased with pyrrhotite formation and the activity was accelerated by the presence of excess sulfur. Activity of pyrite FeS{sub 2} for phenanthrene hydrogenation and activity of natural ground pyrites for cow liquefaction decreased with storage under air. On the other hand, the NEDOL process for a coal liquefaction pilot plant of 150 t/d which is one of the national projects in Japan, will use pyrites as one of the catalysts for the first-stage because FeS{sub 2} has high activity and is low in price. In this paper, we describe in detail the role of iron catalysts in hydroconversion of aromatic hydrocarbons.

Ogata, E.; Horie, Kazuyuki [Univ. of Tokyo (Japan); Wei, Xain-Yong [National Institute of Materials and Chemical Research, Ibaraki (Japan)] [and others

1995-12-31

213

Particle-bound polycyclic aromatic hydrocarbon concentrations in transportation microenvironments  

NASA Astrophysics Data System (ADS)

This study is one of the first case studies to characterize the exposure of urban residents to traffic-related air pollution across locations and transportation microenvironments during everyday activities. Twenty-four adult residents of Boyle Heights, a neighborhood near downtown Los Angeles, carried a portable air pollution monitor and a Global Positioning Systems (GPS) tracking device for a total of 96 days. We found significant spatial and temporal variation in the particle-bound polycyclic aromatic hydrocarbon (pPAH) concentrations in transportation microenvironments. Average pPAH concentrations were higher while walking outdoors (190 ng m-3) compared to traveling in private passenger vehicles (138-155 ng m-3) or traveling in public transportation (61-124 ng m-3). Although travel comprised 5% of participant days, it was associated with 27% of overall daily pPAH exposure. Regression models explained 40-55% of the variation in daily average pPAH concentrations, and 40-44% of the variation in 1-min interval concentrations. Important factors included time spent traveling, travel speed, meteorological and nearby land use factors, time of day, and proximity to roadways. Although future research is needed to develop stronger predictive models, our study demonstrates portable tracking devices can provide a more complete, diurnal characterization of air pollution exposures for urban populations.

Houston, Douglas; Wu, Jun; Yang, Dongwoo; Jaimes, Guillermo

2013-06-01

214

Distribution of polycyclic aromatic hydrocarbons in lime spray dryer ash  

SciTech Connect

Four lime spray dryer (LSD) ash samples were collected from a spreader stoker boiler and measured for their concentrations of 16 U.S. EPA specified polycyclic aromatic hydrocarbons (PAHs). Results showed that the total measured PAH concentration correlated with the organic carbon content of the LSD ash. Each LSD ash sample was then separated using a 140 mesh sieve into two fractions: a carbon-enriched fraction ({gt}140 mesh) and a lime-enriched fraction ({lt}140 mesh). Unburned carbon was further separated from the carbon-enriched fraction with a lithiumheteropolytungstate (LST) solution. PAH measurements on these different fractions showed that unburned carbon had the highest PAH concentrations followed by the carbon-enriched fraction, indicating that PAHs were primarily associated with the carbonaceous material in LSD ash. However, detectable levels of PAHs were also found in the lime-enriched fraction, suggesting that the fine spray of slaked lime may sorb PAH compounds from the flue gas in the LSD process. 37 refs., 5 figs., 4 tabs.

Ping Sun; Panuwat Taerakul; Linda K. Weavers; Harold W. Walker [Ohio State University, Columbus, OH (United States). Department of Civil and Environmental Engineering and Geodetic Science

2005-10-01

215

Investigation of polycyclic aromatic hydrocarbons from coal gasification.  

PubMed

The hazardous organic pollutants generated from coal gasification, such as polycyclic aromatic hydrocarbons(PAHs), are highly mutagenic and carcinogenic. More researchers have paid particular attention to them. Using air and steam as gasification medium, the experiments of three kinds of coals were carried out in a bench-scale atmospheric fluidized bed gasifier. The contents of the 16 PAHs specified by US EPA in raw coal, slag, bag house coke, cyclone coke and gas were measured by HPLC to study the contents of PAHs in raw coal and the effects of the inherent characters of coals on the formation and release of PAHs in coal gasification. The experimental results showed that the distributions of PAHs in the gasified products are similar to raw coals and the total-PAHs content in coal gasification is higher than in raw coal(except Coal C). The total-PAHs contents increase and then decrease with the rise of fixed carbon and sulfur of coal while there has an opposite variation when volatile matters content increase. The quantities of PAHs reduce with the increase of ash content or the drop of heating value during coal gasification. PMID:15900777

Zhou, Hong-cang; Jin, Bao-sheng; Zhong, Zhao-ping; Huang, Ya-ji; Xiao, Rui; Li, Da-ji

2005-01-01

216

Absorption Spectroscopy of Polycyclic Aromatic Hydrocarbons under Interstellar Conditions  

NASA Technical Reports Server (NTRS)

The presence and importance of polycyclic aromatic hydrocarbons (PAHs, a large family of organic compounds containing carbon and hydrogen) in the interstellar medium has already been well established. The Astrochemistry Laboratory at NASA Ames Research Center (under the direction of Louis Allamandola and Scott Sandford) has been the center of pioneering work in performing spectroscopy on these molecules under simulated interstellar conditions, and consequently in the identification of these species in the interstellar medium by comparison to astronomically obtained spectra. My project this summer was twofold: (1) We planned on obtaining absorption spectra of a number of PAHs and their cations in cold (4K) Ne matrices. The purpose of these experiments was to increase the number of different PAHs for which laboratory spectra have been obtained under these simulated interstellar conditions; and (2) I was to continue the planning and design of a new laser facility that is being established in the Astrochemistry laboratory. The laser-based experimental set-up will greatly enhance our capability in examining this astrophysically important class of compounds.

Stone, Bradley M.

1996-01-01

217

Monitoring polynuclear aromatic hydrocarbons in sediment porewater by SPMD  

NASA Astrophysics Data System (ADS)

A new mimic biological Semi-permeable Membrane Device (SPMD) introduced for sampling organic pollutants yielded satisfactory results when it was first used as a passive sampler to concentrate and determine 16 kinds of polynuclear aromatic hydrocarbons (PAHs) by means of capillary GC on an HP 5890 GC-FID in coastal sediment porewater. The concentration of PAHs in sediment porewater for naphthalene(N), acenaphthlene(AL), acenaphthene(AE), fluorene(F), phenaphthene(P), anthracene(A), fluoranthene(FA), pyrene(Py), benzo[a]anthracene(B[a]A), chrysene(Chr), benzo[b] fluor- anthene(B[b]F), benzo[k]fluoranthene(B[k]F), benzo[a]pyrene(B[a]P), indeno[1,2,3,-cd]-Pyrene(1[123]P), dibenz[a, h]anthracene(D[ah]A) and benzo[g, h, i] perylene(B[ghi]P) were: 50.36, under detection limits(UD), 18.19, 8.41, 8.40, 1.44, UD, 8.01, 524.15, 168.47, 50.13, 123.66, 63.48, 27.40, 82.04 and 58,81 ng/L, respectively.

Zhu, Ya-Xian; Zhang, Yong; Zhang, Jie; Zhuang, Yi-Ting; Ka-Fai, Poon; Lam, Michael H. W.; Hong, Hua-Sheng; Wu, Rudolf S. S.

2001-12-01

218

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

219

Atmospheric concentrations of polycyclic aromatic hydrocarbons during chimney sweeping.  

PubMed

Air sampled from the breathing zone of chimney sweeps during "dirty work" and soot samples were analysed for polycyclic aromatic hydrocarbons (PAH). A total of 20 PAH were quantified by gas chromatography-mass spectrometry in 115 air samples and 18 soot samples. These included benzo(b)fluoranthene, benzo(a)pyrene (BaP), chrysene, dibenz(a,h)anthracene, and indeno (1,2,3-cd)pyrene, all of which are animal carcinogens. The summed atmospheric concentration of these compounds depended on the type of fuel used and averaged 2.27 micrograms/m3 for oil fuel. If a mixture of oil and solid fuel was used the concentration was 5.06 micrograms/m3; pure solid fuel heating yielded 5.08 micrograms/m3. The air concentrations of BaP were 0.36, 0.83, and 0.82 micrograms/m3 respectively. The soot samples recovered after using the three different fuel types were 10.50, 109.10, and 51.25 mg BaP/kg. The maximum total concentrations of the five carcinogenic PAH were 243.70, 691.06, and 213.94 mg/kg respectively. The time weighted, shift mean concentrations of 0.02 to 0.21 micrograms/m3 benzo(a)pyrene obtained on 11 days form the basis for the industrial medical estimation of risk. PMID:2765421

Knecht, U; Bolm-Audorff, U; Woitowitz, H J

1989-07-01

220

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

221

Polycylcic Aromatic Hydrocarbons (PAH's) in dense cloud chemistry  

E-print Network

Virtually all detailed gas-phase models of the chemistry of dense interstellar clouds exclude polycyclic aromatic hydrocarbons (PAH's). This omission is unfortunate because from the few studies that have been done on the subject, it is known that the inclusion of PAH's can affect the gas-phase chemistry strongly. We have added PAH's to our network to determine the role they play in the chemistry of cold dense cores. In the models presented here, we include radiative attachment to form PAH-, mutual neutralization between PAH anions and small positively-charged ions, and photodetachment. We also test the sensitivity of our results to changes in the size and abundance of the PAH's. Our results confirm that the inclusion of PAH's changes many of the calculated abundances of smaller species considerably. In TMC-1, the general agreement with observations is significantly improved contrary to L134N. This may indicate a difference in PAH properties between the two regions. With the inclusion of PAH's in dense cloud chemistry, high-metal elemental abundances give a satisfactory agreement with observations. As a result, we do not need to decrease the observed elemental abundances of all metals and we do not need to vary the elemental C/O ratio in order to produce large abundances of carbon species in TMC-1 (CP).

Valentine Wakelam; Eric Herbst

2008-02-26

222

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

223

Polycyclic aromatic hydrocarbons (PAHs) in the air of Chinese cities.  

PubMed

Polycyclic aromatic hydrocarbons (PAHs) were determined in the air of 37 cities and 3 rural locations across China during the winter, spring, summer and autumn of 2005, using polyurethane foam (PUF) disks as passive air samplers (PAS). Winter and autumn concentrations in cities exceeded spring and summer values. Concentrations were amongst the highest in the world; seasonally averaged autumn/winter values in some cities in the north and north-west of China exceeded proposed European Union air quality standards. Several factors, acting in combination, influenced air concentrations. A significant negative correlation was found between average annual city concentrations and the annual average temperature, while winter time PAH concentrations correlated with estimated coal consumption. The highest total PAH concentrations and loadings of high molecular weight compounds generally occurred in major cities located on higher land (500-2000 m), where relatively cold winters and higher coal consumption occurs. Lower values occurred in cities located in the south and east China and along the coastal regions. Molecular markers indicated incomplete combustion of fossil fuels dominated the urban air and gave evidence for photo-decomposition of selected compounds. PMID:17909643

Liu, Xiang; Zhang, Gan; Li, Jun; Cheng, Hai-Rong; Qi, Shi-Hua; Li, Xiang-Dong; Jones, Kevin C

2007-10-01

224

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

225

Genotoxicity of model and complex mixtures of polycyclic aromatic hydrocarbons  

SciTech Connect

Polycyclic aromatic hydrocarbons (PAHs) are one of the most ubiquitous classes of environmental carcinogens; however, limited information is available to describe their potential genotoxic interactions. This manuscript reports on the interactions of PAHs in complex mixtures as determined in microbial mutagenicity assays. Samples analyzed included separate 2-, 3-, and 4-ring PAH individual model fractions (IMFs) constructed to simulate the composition of a model coal tar. These were tested individually and in various combinations, including a reconstituted model fraction (RMF) composed of all three IMFs. A solvent extract of coal tar and a benzo(a)pyrene-amended extract of coal tar were also tested. The maximum mutagenic response of 1,089 revertants was induced by the RMF at a dose of 90 {micro}g/plate with metabolic activation. At the four lowest dose levels, the response observed in the RMF sample was increased when compared to the 4-ring-IMF sample alone. However, the response observed with the RMF sample at the highest dose tested was less than was observed in the 4-ring-IMF sample tested independently. When IMF samples were combined or mixed with individual chemicals, some inhibition was observed. These data indicate that mixtures of PAHs can exhibit a variety of mutagenic interactions controlled by both the metabolism of the PAHs and by their concentration in the mixture.

Donnelly, K.C.; Phillips, T.D.; Onufrock, A.M.; Collie, S.L.; Huebner, H.J.; Washburn, K.S. [Texas A and M Univ., College Station, TX (United States). Dept. of Veterinary Anatomy and Public Health

1996-12-31

226

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

227

An Evaluation of Polycyclic Aromatic Hydrocarbon Uptake into Polyethylene Samplers  

NASA Astrophysics Data System (ADS)

Polyethylene passive samplers (PEs) are simple reliable tools that have been widely used in the detection of hydrophobic organic compounds. Thick (>200?m or greater) PEs have important applications to specific sampling scenarios including biological assays, deployment on ships and aircraft (towing) and long term sampling, however little is known about their uptake kinetics. This study aimed to develop an accurate understanding of the uptake kinetics of these thick PEs. PE passive samplers of equal surface area, but differing thicknesses were co-deployed in the surface water and air of lower Narragansett Bay in 2013 to characterize differences in their uptake of polycyclic aromatic hydrocarbons (PAHs). PE samplers of approximately 50, 800, and 1600?m thicknesses were analyzed for 38 parent and alkylated PAHs, with replicate sampler reproducibility mostly within 25%. A number of smaller PAHs (typically those with a molecular weight less than 180) analyzed over a 4 week deployment equilibrated, while the larger molecules remained in the linear or curve linear uptake stages. Results from a second, 24 week deployment of 800?m and 1600?m samplers in surface waters suggest that all 38 compounds studied remained in the linear uptake stage. The PE-weight normalized concentration ratio of 1600?m to 800?m sampler fell below 1 for all analytes, implying equilibrium had not been established.

Martynowych, D. J.; McDonough, C.; Lohmann, R.

2013-12-01

228

Complete Genome Sequence of a Novel Bacterium within the Family Rhodocyclaceae That Degrades Polycyclic Aromatic Hydrocarbons  

PubMed Central

A polycyclic aromatic hydrocarbon-degrading bacterium designated strain Ca6, a member of the family Rhodocyclaceae and a representative of the uncharacterized pyrene group 1 (PG1), was isolated and its genome sequenced. The presence of several genes suspected to be associated with PG1 was confirmed, and additional genes for aromatic compound metabolism were detected.

Dickey, Allison N.; Scholl, Elizabeth H.; Wright, Fred A.; Aitken, Michael D.

2015-01-01

229

Biodegradation of High-Molecular-Weight Polycyclic Aromatic Hydrocarbons by Bacteria  

Microsoft Academic Search

Interest in the biodegradation mechanisms and environ- mental fate of polycyclic aromatic hydrocarbons (PAHs) is prompted by their ubiquitous distribution and their potentially deleterious effects on human health. PAHs constitute a large and diverse class of organic compounds and are generally de- scribed as molecules which consist of three or more fused aromatic rings in various structural configurations (5). The

ROBERT A. KANALY; SHIGEAKI HARAYAMA

2000-01-01

230

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

Code of Federal Regulations, 2013 CFR

...Subpt. E, Table 2C Table 2C to Subpart E of Part 59—Reactivity Factors for Aromatic Hydrocarbon Solvent Mixtures Bin Boiling range(degrees F) Criteria Reactivityfactor (g O3 /g VOC) 21 280-290 Aromatic Content (?98%)...

2013-07-01

231

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

232

Polycyclic Aromatic Hydrocarbon (PAH) Exposure and DNA Adduct Semi-Quantitation in Archived Human Tissues  

PubMed Central

Polycyclic aromatic hydrocarbons (PAHs) are combustion products of organic materials, mixtures of which contain multiple known and probable human carcinogens. PAHs occur in indoor and outdoor air, as well as in char-broiled meats and fish. Human exposure to PAHs occurs by inhalation, ingestion and topical absorption, and subsequently formed metabolites are either rendered hydrophilic and excreted, or bioactivated and bound to cellular macromolecules. The formation of PAH-DNA adducts (DNA binding products), considered a necessary step in PAH-initiated carcinogenesis, has been widely studied in experimental models and has been documented in human tissues. This review describes immunohistochemistry (IHC) studies, which reveal localization of PAH-DNA adducts in human tissues, and semi-quantify PAH-DNA adduct levels using the Automated Cellular Imaging System (ACIS). These studies have shown that PAH-DNA adducts concentrate in: basal and supra-basal epithelium of the esophagus, cervix and vulva; glandular epithelium of the prostate; and cytotrophoblast cells and syncitiotrophoblast knots of the placenta. The IHC photomicrographs reveal the ubiquitous nature of PAH-DNA adduct formation in human tissues as well as PAH-DNA adduct accumulation in specific, vulnerable, cell types. This semi-quantative method for PAH-DNA adduct measurement could potentially see widespread use in molecular epidemiology studies. PMID:21845152

Pratt, M. Margaret; John, Kaarthik; MacLean, Allan B.; Afework, Senait; Phillips, David H.; Poirier, Miriam C.

2011-01-01

233

Separation of {sup 32}P-postlabeled DNA adducts of polycyclic aromatic hydrocarbons and nitrated polycyclic aromatic hydrocarbons by HPLC  

SciTech Connect

The {sup 32}P-postlabeling assay, thin-layer chromatography, and reverse-phase high-pressure liquid chromatography (HPLC) were used to separate DNA adducts formed from 10 polycyclic aromatic hydrocarbons (PAHs) and 6 nitrated polycyclic aromatic hydrocarbons (NO{sub 2}-PAHs). The PAHs included benzo[j]fluoranthene, benzo[k]fluoranthene, indeno[1,2,3-cd]pyrene, benzo[a]pyrene, chrysene, 6-methylchrysene, 5-methylchrysene, and benz[a]anthracene. The NO{sub 2}-PAHs included 1-nitropyrene, 2-nitrofluoranthene, 3-nitrofluoranthene, 1,6-dinitropyrene, 1,3-dinitropyrene, and 1,8-dinitropyrene. Separation of seven of the major PAH-DNA adducts was achieved by an initial PAH HPLC gradient system. The major NO{sub 2}-PAH-DNA adducts were not all separated from each other using the initial PAH HPLC gradient but were clearly separated from the PAH-DNA adducts. A second NO{sub 2}-PAH HPLC gradient system was developed to separate NO{sub 2}-PAH-DNA adducts following one-dimensional TLC and HPLC analysis. HPLC profiles of NO{sub 2}-PAH-DNA adducts were compared using both adduct enhancement versions of the {sup 32}P-postlabeling assay to evaluate the use of this technique on HPLC to screen for the presence of NO{sub 2}-PAH-DNA adducts. To demonstrate the application of these separation methods to a complex mixture of DNA adducts, the chromatographic mobilities of the {sup 32}P-postlabeled DNA adduct standards (PAHs and NO{sub 2}-PAHs) were compared with those produced by a complex mixture of polycyclic organic matter (POM) extracted from diesel emission particles. The diesel-derived adducts did not elute with the identical retention time of any of the PAH or NO{sub 2}-PAH standards used in this study. HPLC analyses of the NO{sub 2}-PAH-derived adducts (butanol extracted) revealed the presence of multiple DNA adducts.

King, L.C.; Gallagher, J.E.; Lewtas, J. [Environmental Protection Agency, Research Triangle Park, NC (United States); George, M. [Integrated Lab. Systems, Research Triangle Park, NC (United States)

1994-07-01

234

Evaluation of sediment contamination by polycyclic aromatic hydrocarbons in the Gironde estuary  

Microsoft Academic Search

Surface sediments, collected in the Gironde estuary during February and October 1993, were analysed for polycyclic aromatic hydrocarbons (PAHs). The aromatic fractions were separated by liquid chromatography of the extracts and analysed by gas chromatography\\/mass spectrometry (GC\\/MS). Total PAH concentrations ranged among 1000 to 2000 ng\\/g of dry sediment. The resulting distributions and molecular ratios of specific aromatic compounds (phenanthrene,

H. Budzinski; I. Jones; J. Bellocq; C. Piérard; P. Garrigues

1997-01-01

235

Dissolved\\/dispersed Petroleum Aromatic Hydrocarbons in the São Sebastião Channel, São Paulo, Brazil  

Microsoft Academic Search

A monitoring programme at São Sebastião Channel, São Paulo, Brazil, was conducted in terms of dissolved\\/dispersed petroleum aromatic hydrocarbons (DDPAH) in water analysed by flourescence spectroscopy. The study was done in order to establish a baseline data for this area and verify the petroleum hydrocarbon influence from the oil terminal (DTCS) and other human activities over the channel. The DDPAH

Eliete Zanardi; Márcia Caruso B??cego; Rolf Roland Weber

1999-01-01

236

SAMPLING AND ANALYSIS OF POLYCYCLIC AROMATIC HYDROCARBONS (PAH) AND OXYGENATED PAH IN  

E-print Network

SAMPLING AND ANALYSIS OF POLYCYCLIC AROMATIC HYDROCARBONS (PAH) AND OXYGENATED PAH IN DIESEL Hydrocarbons (PAH) and their oxygenated derivatives occur in particles or in the vapour phase in the atmosphere that is the result of the incomplete combustion of diesel fuel and lubricants. In general 10 % to 40

Paris-Sud XI, Université de

237

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

E-print Network

with significant decreases in T4, suggesting a potential negative effect on the endocrine system of nestling bald--Polyhalogenated aromatic hydrocarbons are global contaminants that are often considered to be endocrine disruptors hydrocarbons (PHAHs), many of which are considered to be endocrine disruptors, has been well documented [1

238

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

239

Extended Y-rule method for the characterization of the aromatic sextets in cata-condensed polycyclic aromatic hydrocarbons.  

PubMed

The location, number, and migrating behavior of the sextets in the cata-condensed benzenoid polycyclic aromatic hydrocarbons with available bay regions have been determined by a new proposed topological methodology called the extended Y-rule. The precursor of this rule is the well-known Y-rule method for determining sextets in peri-condensed polycyclic aromatic hydrocarbons. The new methodology has been successfully validated by means of literature information and by theoretical nucleus independent chemical shift (NICS) calculations. Even though the families of polycyclic aromatic hydrocarbons analyzed here comprise the C14H10, C18H12, C22H14, and C26H16 isomers, the procedure can practically be extended to the families C(10+4x)H(8+2x), where x = 1, ..., ?. It is the first time that a straightforward procedure, easy to apply, has been proposed to obtain the sextets arrangement and behavior in the group of cata-condensed benzenoid polycyclic aromatic hydrocarbons. PMID:25455151

Oña-Ruales, Jorge O; Ruiz-Morales, Yosadara

2014-12-26

240

Aryl hydrocarbon receptor expression is associated with a family history of upper gastrointestinal tract cancer in a high-risk population exposed to aromatic hydrocarbons  

SciTech Connect

Polycyclic aromatic hydrocarbon (PAH) exposure is a risk factor for esophageal squamous cell carcinoma, and PAHs are ligands of the aryl hydrocarbon receptor (AhR). This study measured the expression of AhR and related genes in frozen esophageal cell samples from patients exposed to different levels of indoor air pollution, who did or did not have high-grade squamous dysplasia and who did or did not have a family history of upper gastrointestinal tract (UGI) cancer. 147 samples were evaluated, including 23 (16%) from patients with high-grade dysplasia and 48 (33%) from patients without dysplasia who heated their homes with coal, without a chimney (a 'high' indoor air pollution group), and 27 (18%) from patients with high-grade dysplasia and 49 (33%) from patients without dysplasia who did not heat their homes at all (a 'low' indoor air pollution group). Sixty-four (44%) had a family history of UGI cancer. RNA was extracted and quantitative PCR analysis was done. AhR gene expression was detectable in 85 (58%) of the samples and was >9-fold higher in those with a family history of UGI cancer (median expression (interquartile range), -1,964 (-18,000, -610) versus -18,000 (-18,000, -1036); P = 0.02, Wilcoxon rank-sum test). Heating status, dysplasia category, age, gender, and smoking were not associated with AhR expression (linear regression; all P values {ge} 0.1). AhR expression was higher in patients with a family history of UGI cancer. Such individuals may be more susceptible to the deleterious effects of PAH exposure, including PAH-induced cancer.

Roth, M.J.; Wei, W.Q.; Baer, J.; Abnet, C.C.; Wang, G.Q.; Sternberg, L.R.; Warner, A.C.; Johnson, L.L.; Lu, N.; Giffen, C.A.; Dawsey, S.M.; Qiao, Y.L.; Cherry, J. [NCI, Bethesda, MD (United States)

2009-09-15

241

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

242

Sanguinarine activates polycyclic aromatic hydrocarbon associated metabolic pathways in human oral keratinocytes and tissues  

Microsoft Academic Search

Sanguinarine's use in human clinical applications is currently controversial. While some studies have demonstrated sanguinarine's anti-inflammatory and anti-oxidant properties, other investigations reported sanguinarine's procarcinogenic effects. Like the tobacco-associated carcinogen, benzo(a)pyrene (B(a)P), sanguinarine is a polycyclic aromatic hydrocarbon (PAH). PAH exposure activates the aryl hydrocarbon transcription activating factor (AhR), resulting in nuclear translocation, binding to the aryl hydrocarbon nuclear translocator (ARNT),

Jeffrey M. Karp; Kapila A. Rodrigo; Ping Pei; Matthew D. Pavlick; Jeffrey D. Andersen; Dennis J. McTigue; Henry W. Fields; Susan R. Mallery

2005-01-01

243

Analysis and fate of aliphatic hydrocarbons, linear alkylbenzenes, polychlorinated biphenyls and polycyclic aromatic hydrocarbons in sewage sludge-amended soils  

Microsoft Academic Search

Different extraction and clean-up methods for the multi-residue determination of aliphatic hydrocarbons (AHCs), linear alkylbenzenes (LABs), polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) in sewage sludge-amended soil were investigated. Soxhlet extraction with dichloromethane and actived silica gel clean-up provided the best results. HRGC with FID detection, HRGC with ECD detection, and HPLC with a programmable fluorescence detection, performed accurate

E. Mangas; M. T. Vaquero; L. Comellas; F. Broto-Puig

1998-01-01

244

Assessment of population exposure to Polycyclic Aromatic Hydrocarbons (PAHs) using integrated models and evaluation of uncertainties  

NASA Astrophysics Data System (ADS)

Polycyclic Aromatic Hydrocarbons (PAHs) are considered among the most dangerous air pollutants due to their carcinogenic and mutagenic characteristics. Populations living in urban area are exposed to these pollutants because of their proximity to the emission sources. However, the spatial and temporal characteristics of PAHs concentrations in such areas are not well known. An integrated modeling approach is here presented to estimate exposure to PAHs content in PM2.5 of children and elderly people living in the city of Rome, Italy. It is based on a microenvironment approach in which exposure is estimated by accounting for PAHs concentrations experienced by the target population in the most visited living environments. The model uses data provided by the EU LIFE + EXPAH project: indoor/outdoor PAHs concentrations collected in homes, schools, cars, buses and offices to derive PAHs infiltration factors for the specific environments; time activity to identify daytime profiles of the target population and information on the prevailing living environments; ambient PAHs concentration fields. The latter have been obtained by integrating Chemical Transport Model (CTM) results with measurements collected by the EXPAH project. Uncertainties in the estimation of PAHs exposure has been evaluated by applying a Monte Carlo statistical approach using probability density function based on observed exposure parameters. Results were calculated for one year (June 2011-May 2012). The downtown area was found to be the most contaminated one with concentrations up to 2 ± 1 and 0.6 ± 0.2 ng/m3, on an annual basis, respectively for ?4PAHs (e.g. B[a]P, B[b]F, B[k]F and indeno(1,2,3-cd)pyrene) and B[a]P. Results do not exhibit significant differences on ?4PAHs exposure between children and elderly people, mainly due to the prevalence of indoor microenvironments in the time activity data, and to the little difference in the indoor/outdoor infiltration. Seasonality was identified as an important factor contributing to the overall exposure. The higher PAHs emissions during the heating period determine a greater exposure during winter. Homes have been identified as the microenvironments that most contribute to PAHs exposure followed by schools.

Gariazzo, Claudio; Lamberti, Mafalda; Hänninen, Otto; Silibello, Camillo; Pelliccioni, Armando; Porta, Daniela; Cecinato, Angelo; Gherardi, Monica; Forastiere, Francesco

2015-01-01

245

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, ...

246

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

247

Infrared Spectroscopy of Polycyclic Aromatic Hydrocarbon Cations. 3; The Members  

NASA Technical Reports Server (NTRS)

In spite of the fact that the infrared spectroscopic properties of only a few isolated ionized polycyclic aromatic hydrocarbons (PAHs) are known, gaseous, ionized PAHs are thought to be responsible for a very common family of infrared interstellar emission bands. In order to provide a data base to test this hypothesis and, if borne out, to use this emission band family as a probe of many different interstellar environments, we are carrying out a thorough study of the infrared spectroscopic properties of neutral and ionized PAHs in argon matrices. Here we present 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[ghilperylene, and coronene. The properties of naphthalene, the first member of the series, are given elsewhere. The spectra of perdeuterated phenanthrene and pyrene are also reported. For those molecules which have been previously studied (pyrene, d(10)-pyrene, and coronene), band positions and relative intensities are in agreement. In all cases we report additional features. Absolute integrated absorbance values are given for the phenanthrene, perdeutero-phenanthrene, 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 which are an order of magnitude stronger than for the neutral species, and the CH out-of-plane bends produce bands which are 5-20 times weaker than in 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.; Wittebon, Fred C. (Technical Monitor)

1994-01-01

248

Biodegradation of polycyclic aromatic hydrocarbons by a halophilic microbial consortium.  

PubMed

In this study we investigated the phenanthrene degradation by a halophilic consortium obtained from a saline soil sample. This consortium, named Qphe, could efficiently utilize phenanthrene in a wide range of NaCl concentrations, from 1% to 17% (w/v). Since none of the purified isolates could degrade phenanthrene, serial dilutions were performed and resulted in a simple polycyclic aromatic hydrocarbon (PAH)-degrading culture named Qphe-SubIV which was shown to contain one culturable Halomonas strain and one unculturable strain belonging to the genus Marinobacter. Qphe-SubIV was shown to grow on phenanthrene at salinities as high as 15% NaCl (w/v) and similarly to Qphe, at the optimal NaCl concentration of 5% (w/v), could degrade more than 90% of the amended phenanthrene in 6 days. The comparison of the substrate range of the two consortiums showed that the simplified culture had lost the ability to degrade chrysene but still could grow on other polyaromatic substrates utilized by Qphe. Metabolite analysis by HPLC and GC-MS showed that 2-hydroxy 1-naphthoic acid and 2-naphthol were among the major metabolites accumulated in the Qphe-SubIV culture media, indicating that an initial dioxygenation step might proceed at C1 and C2 positions. By investigating the growth ability on various substrates along with the detection of catechol dioxygenase gene, it was postulated that the uncultured Marinobacter strain had the central role in phenanthrene degradation and the Halomonas strain played an auxiliary role in the culture by utilizing phenanthrene metabolites whose accumulation in the media could be toxic. PMID:22086071

Dastgheib, Seyed Mohammad Mehdi; Amoozegar, Mohammad Ali; Khajeh, Khosro; Shavandi, Mahmoud; Ventosa, Antonio

2012-08-01

249

Microbial Dioxygenase Gene Population Shifts during Polycyclic Aromatic Hydrocarbon Biodegradation  

PubMed Central

The degradation of polycyclic aromatic hydrocarbons (PAHs) by bacteria has been widely studied. While many pure cultures have been isolated and characterized for their ability to grow on PAHs, limited information is available on the diversity of microbes involved in PAH degradation in the environment. We have designed generic PCR primers targeting the gene fragment encoding the Rieske iron sulfur center common to all PAH dioxygenase enzymes. These Rieske primers were employed to track dioxygenase gene population shifts in soil enrichment cultures following exposure to naphthalene, phenanthrene, or pyrene. PAH degradation was monitored by gas chromatograph with flame ionization detection. DNA was extracted from the enrichment cultures following PAH degradation. 16S rRNA and Rieske gene fragments were PCR amplified from DNA extracted from each enrichment culture and an unamended treatment. The PCR products were cloned and sequenced. Molecular monitoring of the enrichment cultures before and after PAH degradation using denaturing gradient gel electrophoresis and 16S rRNA gene libraries suggests that specific phylotypes of bacteria were associated with the degradation of each PAH. Sequencing of the cloned Rieske gene fragments showed that different suites of genes were present in soil microbe populations under each enrichment culture condition. Many of the Rieske gene fragment sequences fell into clades which are distinct from the reference dioxygenase gene sequences used to design the PCR primers. The ability to profile not only the bacterial community but also the dioxygenases which they encode provides a powerful tool for both assessing bioremediation potential in the environment and for the discovery of novel dioxygenase genes. PMID:16751518

Ní Chadhain, Sinéad M.; Norman, R. Sean; Pesce, Karen V.; Kukor, Jerome J.; Zylstra, Gerben J.

2006-01-01

250

Sorption characteristics of polycyclic aromatic hydrocarbons in aluminum smelter residues.  

PubMed

High temperature carbon oxidation in primary aluminum smelters results in the release of polycyclic aromatic hydrocarbons (PAH) into the environment. The main source of PAH are the anodes, which are composed of petroleum coke (black carbon, BC) and coal tar pitch. To elucidate the dominant carbonaceous phase controlling the environmental fate of PAH in aluminum smelter residues (coke BC and/or coal tar), the sorptive behavior of PAHs has been determined, using passive samplers and infinitesink desorption methods. Samples directly from the wet scrubber were studied as well as ones from an adjacent 20-year old storage lagoon and roof dust from the smelter. Carbon-normalized distribution coefficients of native PAHs were 2 orders of magnitude higher than expected based on amorphous organic carbon (AOC)/water partitioning, which is in the same order of magnitude as reported literature values for soots and charcoals. Sorption isotherms of laboratory-spiked deuterated phenanthrene showed strong (-100 times stronger than AOC) but nonetheless linear sorption in both fresh and aged aluminum smelter residues. The absence of nonlinear behavior typical for adsorption to BC indicates that PAH sorption in aluminum smelter residues is dominated by absorption into the semi-solid coal tar pitch matrix. Desorption experiments using Tenax showed that fresh smelter residues had a relatively large rapidly desorbing fraction of PAH (35-50%), whereas this fraction was strongly reduced (11-16%) in the lagoon and roof dust material. Weathering of the coal tar residue and/or redistribution of PAH between coal tar and BC phases could explain the reduced availability in aged samples. PMID:17438813

Breedveld, Gijs D; Pelletier, Emilien; St Louis, Richard; Cornelissen, Gerard

2007-04-01

251

Polycyclic Aromatic Hydrocarbons and the Diffuse Interstellar Bands: A Survey  

NASA Astrophysics Data System (ADS)

We discuss the proposal of relating the origin of some of the diffuse interstellar absorption bands (DIBs) to neutral polycyclic aromatic hydrocarbons (PAHs) present in translucent interstellar clouds. An assessment of ionized PAHs will be examined in a future report. The spectra of several cold, isolated gas-phase PAHs have been measured in the laboratory under experimental conditions that mimic the interstellar conditions and are compared with an extensive set of astronomical spectra of reddened, early-type stars. This comparison provides—for the first time—accurate upper limits for the abundances of specific PAH molecules along specific lines of sight, something not attainable from IR observations alone. The comparison of these unique laboratory data with high-resolution, high signal-to-noise ratio spectra leads to two major findings: (1) a finding specific to the individual molecules that were probed in this study and, which leads to the clear and unambiguous conclusion that the abundance of these specific neutral PAHs must be very low in the individual translucent interstellar clouds that were probed in this survey (PAH features remain below the level of detection) and, (2) a general finding that neutral PAHs exhibit intrinsic band profiles that are similar to the profile of the narrow DIBs indicating that the carriers of the narrow DIBs must have close molecular structure and characteristics. This study is the first quantitative survey of neutral PAHs in the optical range and it opens the way for unambiguous quantitative searches of PAHs in a variety of interstellar and circumstellar environments.

Salama, F.; Galazutdinov, G. A.; Kre?owski, J.; Biennier, L.; Beletsky, Y.; Song, In-Ok

2011-02-01

252

Emission of polycyclic aromatic hydrocarbons from selected processes in steelworks.  

PubMed

The emission of polycyclic aromatic hydrocarbons from selected processes in steelworks in southern Poland was investigated. Size-segregated samples of air particulate matter (<0.25, 0.25-0.5, 0.5-1.0, 1.0-2.5 and 2.5-10 ?m) were collected at the electric arc furnace and rolling mill. The PAHs were sampled with the personal cascade impactor and identified by HPLC with fluorescence detector. The obtained results showed that collected PAH contents were significantly higher at the electric arc furnace. The highest content of total PAHs (93 ng m(-3)) was present in the smallest particles of 0.5 ?m aerodynamic diameter or less, indicating that the ultrafine particles have a high contribution in the overall PM(2.5) fine fraction. Concentrations of Py, CH, BbF, BaP and BghiP came to 76% of total PAHs content in <0.25 ?m fraction. The five- and six-ring compounds (BbF, BkF, BaP, DBA, BghiP) with 4-ring chrysene presented typical unimodal size distribution with one predominant peak for this particles' diameter. Phenanthrene and fluoranthene exhibited highest concentrations on coarse particles in the range of 10-2.5 ?m, decreasing with decrease of a particle size fraction. Using the toxic equivalent factor (TEF), the mean contributions of the carcinogenic potency of BaP to the air samples collected at the arc furnace and rolling mill (fraction below 0.25 ?m) were determined to be 66.3% and 50.3%, respectively. PMID:20675043

Baraniecka, Joanna; Pyrzy?ska, Krystyna; Szewczy?ska, Ma?gorzata; Po?niak, Ma?gorzata; Dobrzy?ska, Elzbieta

2010-11-15

253

Polyhalogenated aromatic hydrocarbons in surface sediments from Three Gorges Reservoir.  

PubMed

This study was conducted to investigate the current contamination status of polyhalogenated aromatic hydrocarbons (PHAHs) in sediments from the mainstream and 22 primary tributaries of the Yangtze River in the Three Gorges Reservoir region. To accomplish this, the concentrations of 22 polybrominated biphenyl (PBB) congeners, 27 polybrominated diphenyl ether (PBDE) congeners, and 27 polychlorinated biphenyl (PCB) congeners in sediment samples were measured by GC-MS/MS. The result showed that the observed values of PBBs and PBDEs were 22.41 and 35.24 pg g(-1) dw, respectively. PBB1, 31 and 103 were the predominant PBB congeners, while PBDE28, 47, 77 and 99 were the predominant PBDE congeners. PBB209 and BDE209 were detected in >39% of the samples, with geometric means 2.43 and 11.92 pg g(-1) dw, respectively. PCBs were found to be the predominant compounds in sediment samples among the three PHAH subfamilies, with a geometric mean of 1,231.11 pg g(-1) dw, and PCB8, 18, 28, 52 and 66 were the primary PCB congeners. The measured levels of PHAHs were compared with results recently reported in the literature and their respective sediment quality guidelines recommended by the USEPA. The levels of PHAHs in the present study were generally lower than their respective threshold-effect levels, or were comparable to those reported in relatively uncontaminated freshwater samples from other regions. Taken together, these results suggest that, in the reservoir, toxic biological effects on aquatic biota in response to PHAHs contamination of sediments can be expected to be negligible. PMID:23043334

Zhao, Gaofeng; Li, Kun; Zhou, Huaidong; Liu, Xiaoru; Zhang, Panwei; Wen, Wu; Yu, Yang; Yuan, Hao

2013-01-01

254

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

255

Ambient polycyclic aromatic hydrocarbons and pulmonary function in children.  

PubMed

Few studies have examined the relationship between ambient polycyclic aromatic hydrocarbons (PAHs) and pulmonary function in children. Major sources include vehicular emissions, home heating, wildland fires, agricultural burning, and power plants. PAHs are an important component of fine particulate matter that has been linked to respiratory health. This cross-sectional study examines the relationship between estimated individual exposures to the sum of PAHs with 4, 5, or 6 rings (PAH456) and pulmonary function tests (forced expiratory volume in one second (FEV1) and forced expiratory flow between 25% and 75% of vital capacity) in asthmatic and non-asthmatic children. We applied land-use regression to estimate individual exposures to ambient PAHs for averaging periods ranging from 1 week to 1 year. We used linear regression to estimate the relationship between exposure to PAH456 with pre- and postbronchodilator pulmonary function tests in children in Fresno, California (N=297). Among non-asthmatics, there was a statistically significant association between PAH456 during the previous 3 months, 6 months, and 1 year and postbronchodilator FEV1. The magnitude of the association increased with the length of the averaging period ranging from 60 to 110?ml decrease in FEV1 for each 1?ng/m(3) increase in PAH456. There were no associations with PAH456 observed among asthmatic children. We identified an association between annual PAHs and chronic pulmonary function in children without asthma. Additional studies are needed to further explore the association between exposure to PAHs and pulmonary function, especially with regard to differential effects between asthmatic and non-asthmatic children. PMID:24938508

Padula, Amy M; Balmes, John R; Eisen, Ellen A; Mann, Jennifer; Noth, Elizabeth M; Lurmann, Frederick W; Pratt, Boriana; Tager, Ira B; Nadeau, Kari; Hammond, S Katharine

2015-05-01

256

Polycyclic aromatic hydrocarbons in mountain soils of the subtropical Atlantic.  

PubMed

Surface soil samples from various altitudes on Tenerife Island, ranging from sea level up to 3400 m above mean sea level, were analyzed to study the distribution of 26 polycyclic aromatic hydrocarbons (PAHs) in a remote subtropical area. The stable atmospheric conditions in this island define three vertically stratified layers: marine boundary, trade-wind inversion, and free troposphere. Total PAH concentrations, 1.9 to 6000 microg/kg dry wt., were high when compared with those in tropical areas and in a similar range to those in temperate areas. In the marine boundary layer, fluoranthene (Fla), pyrene (Pyr), benz [a]anthracene (BaA), and chrysene (C + T) were largely dominant. The predominance of Fla over Pyr may reflect photo-oxidative processes during atmospheric transport, although coal combustion inputs cannot be excluded. The PAHs found in higher concentration in the soils from the inversion layer were benzo[b + j]fluoranthene (BbjF) + benzo[k]fluoranthene (BkF) > benzo[e]pyrene (BeP) approximately indeno[1,2, 3-cd]pyrene (Ind) > benzo[a]pyrene (BaP) approximately benzo[ghi]perylene (Bghi) > coronene (Cor) approximately dibenz[a,h]anthracene (Dib), reflecting that high temperatures and insolation prevent the accumulation of PAHs more volatile than BbjF in significant amounts. These climatic conditions involve a process of standardization that prevents the identification of specific PAH sources such as traffic, forest fires, or industrial inputs. Only soils with high total organic carbon (TOC) (e.g., 10-30%) preserve the more volatile compounds such as phenanthrene (Phe), methylphenanthrenes (MPhe), dimethylphenanthrenes (DMPhe), and retene (Ret). However, no relation between PAHs and soil TOC and black carbon (BC) was found. The specific PAH distributions of the free tropospheric region suggest a direct input from pyrolytic processes related to the volcanic emission of gases in Teide. PMID:12809298

Ribes, A; Grimalt, J O; Torres García, C J; Cuevas, E

2003-01-01

257

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

258

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

259

A new supramolecular system of racemic-bis-beta-naphthol, benzoquinone and aromatic hydrocarbon, which shows high molecular recognition ability.  

PubMed

Racemic-bis-beta-naphthol, benzoquinone and aromatic hydrocarbons formed a new three component supramolecular system as black crystals. X-ray analysis of the crystals shows that (+)- and (-)-bis-beta-naphthol and benzoquinone form a quinhydrone-type crystalline lattice with aromatic stacking and hydrogen bonding in which the third aromatic hydrocarbon component is accommodated. As the cavity created has a definite shape and size, only hydrocarbons which fit the cavity are selectively included. PMID:12197000

Toda, Fumio; Senzaki, Mami; Kuroda, Reiko

2002-08-21

260

Optimization and determination of polycyclic aromatic hydrocarbons in biochar-based fertilizers.  

PubMed

The agronomic benefit of biochar has attracted widespread attention to biochar-based fertilizers. However, the inevitable presence of polycyclic aromatic hydrocarbons in biochar is a matter of concern because of the health and ecological risks of these compounds. The strong adsorption of polycyclic aromatic hydrocarbons to biochar complicates their analysis and extraction from biochar-based fertilizers. In this study, we optimized and validated a method for determining the 16 priority polycyclic aromatic hydrocarbons in biochar-based fertilizers. Results showed that accelerated solvent extraction exhibited high extraction efficiency. Based on a Box-Behnken design with a triplicate central point, accelerated solvent extraction was used under the following optimal operational conditions: extraction temperature of 78°C, extraction time of 17 min, and two static cycles. The optimized method was validated by assessing the linearity of analysis, limit of detection, limit of quantification, recovery, and application to real samples. The results showed that the 16 polycyclic aromatic hydrocarbons exhibited good linearity, with a correlation coefficient of 0.996. The limits of detection varied between 0.001 (phenanthrene) and 0.021 mg/g (benzo[ghi]perylene), and the limits of quantification varied between 0.004 (phenanthrene) and 0.069 mg/g (benzo[ghi]perylene). The relative recoveries of the 16 polycyclic aromatic hydrocarbons were 70.26-102.99%. PMID:25546393

Chen, Ping; Zhou, Hui; Gan, Jay; Sun, Mingxing; Shang, Guofeng; Liu, Liang; Shen, Guoqing

2015-03-01

261

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

262

Study of volatile hydrocarbon emission control by an aromatic poly(ether imide) membrane  

SciTech Connect

The separation of the mixtures of hydrocarbon vapors from nitrogen was studied by using an asymmetric aromatic poly(ether imide) membrane prepared by the phase-inversion technique. The effect of the presence of water in the feed stream on the separation of hydrocarbon vapors from nitrogen and on the separation of gasoline vapor from nitrogen was also investigated. It was found that the asymmetric membrane is effective for the separation of hydrocarbon vapors from nitrogen without silicone rubber coating. It was also found that the permeability of water is far greater than those of hydrocarbon vapors.

Deng, S.; Sourirajan, A.; Matsuura, T. [Univ. of Ottawa, Ontario (Canada); Farnand, B. [Natural Resources Canada, Ottawa, Ontario (Canada). CANMET-ERL Div.

1995-12-01

263

Polycyclic aromatic hydrocarbons in US and Swedish smokeless tobacco products  

PubMed Central

Background Debate about the health implications of using smokeless tobacco products (STPs) has prompted considerable interest in characterising their levels of toxic and carcinogenic components. In the present study seventy smokeless tobacco products from the US and Sweden, categorized as chewing tobacco, dry and moist snuff, hard and soft pellets, plug, and loose and portion snus, were analysed for twenty one polycyclic aromatic hydrocarbons (PAHs). The tested brands represented 80-90% of the 2008 market share for the major STP categories in these two countries. Results There were significant differences in the total and individual PAH concentrations in the different styles of product. Substantially higher levels of total PAHs (10–60 fold) were found in moist and dry snuff and soft pellets than in the other smokeless tobacco styles. The individual PAH concentrations followed the same patterns as total PAHs except for naphthalene, for which the highest concentrations were found in snus and moist snuff. Good correlations were obtained between benzo[a]pyrene (B[a]P) and all the other PAHs except naphthalene, 1-methylnaphthalene and 2-methylnaphthalene, providing evidence for the first time that it can be used as a good marker for PAHs in STPs. Results were generally in good agreement with two previous studies of PAHs in STPs, except for naphthalene for which significantly lower concentrations were found than previously reported. Analysis of the ratios of different PAHs confirmed that the use of fire-cured tobaccos in the snuffs and soft pellet were the major source of PAHs in these product styles, and provided, for the first time, some indications as to the source of PAHs in the other STP styles, including petrogenic and other combustion sources. Conclusions This study confirms the presence of PAHs in STPs, and identifies substantial differences between the levels in different STP categories. Since previous studies of naphthalene concentrations in STPs differed so markedly from those found in this study, it is recommended that further work on PAH determination is undertaken to investigate the source of this discrepancy. PMID:24011230

2013-01-01

264

Biodegradation aspects of polycyclic aromatic hydrocarbons (PAHs): a review.  

PubMed

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 degradation, microbial degradation is the major degradation process. PAH degradation depends on the environmental conditions, number and type of the microorganisms, nature and chemical structure of the chemical compound being degraded. They are biodegraded/biotransformed into less complex metabolites, and through mineralization into inorganic minerals, H(2)O, CO(2) (aerobic) or CH(4) (anaerobic) and rate of biodegradation depends on pH, temperature, oxygen, microbial population, degree of acclimation, accessibility of nutrients, chemical structure of the compound, cellular transport properties, and chemical partitioning in growth medium. A number of bacterial species are known to degrade PAHs and most of them are isolated from contaminated soil or sediments. Pseudomonas aeruginosa, Pseudomons fluoresens, Mycobacterium spp., Haemophilus spp., Rhodococcus spp., Paenibacillus spp. are some of the commonly studied PAH-degrading bacteria. Lignolytic fungi too have the property of PAH degradation. Phanerochaete chrysosporium, Bjerkandera adusta, and Pleurotus ostreatus are the common PAH-degrading fungi. Enzymes involved in the degradation of PAHs are oxygenase, dehydrogenase and lignolytic enzymes. Fungal lignolytic enzymes are lignin peroxidase, laccase, and manganese peroxidase. They are extracellular and catalyze radical formation by oxidation to destabilize bonds in a molecule. The biodegradation of PAHs has been observed under both aerobic and anaerobic conditions and the rate can be enhanced by physical/chemical pretreatment of contaminated soil. Addition of biosurfactant-producing bacteria and light oils can increase the bioavailability of PAHs and metabolic potential of the bacterial community. The supplementation of contaminated soils with compost materials can also enhance biodegradation without long-term accumulation of extractable polar and more available intermediates. Wetlands, too, have found an application in PAH removal from wastewater. The intensive biological activities in such an ecosystem lead to a high rate of autotrophic and heterotrophic processes. Aquatic weeds Typha spp. and Scirpus lacustris have been used in horizontal-vertical macrophyte based wetlands to treat PAHs. An integrated approach of physical, chemical, and biological degradation may be adopted to get synergistically enhanced removal rates and to treat/remediate the contaminated sites in an ecologically favorable process. PMID:19442441

Haritash, A K; Kaushik, C P

2009-09-30

265

DNA adducts and carcinogenicity of nitro-polycyclic aromatic hydrocarbons.  

PubMed Central

We have been interested in the structure-activity relationships of nitro-polycyclic aromatic hydrocarbons (nitro-PAHs), and have focused on the correlation of structural and electronic features with biological activities, including mutagenicity and tumorigenicity. In our studies, we have emphasized 1-, 2-, 3-, and 6-nitrobenzo[a]pyrenes (nitro-B[a]Ps) and related compounds, all of which are derived from the potent carcinogen benzo[a]pyrene. While 1-, 2-, and 3-nitro-B[a]P are potent mutagens in Salmonella, 6-nitro-B[a]P is a weak mutagen. In vitro metabolism of 1- and 3-nitro-B[a]P has been found to generate multiple pathways for mutagenic activation. The formation of the corresponding trans-7,8-dihydrodiols and 7,8,9,10-tetrahydrotetrols suggests that 1- and 3-nitro-B[a]P trans-7,8-diol-9,10-epoxides are ultimate metabolites of the parent nitro-B[a]Ps. We have isolated a DNA adduct from the reaction between 3-nitro-B[a]P trans-7,8-diol-anti9,10-epoxide and calf thymus DNA, and identified it as 10-(deoxyguanosin-N2-yl)-7,8,9-trihydroxy-7,8,9,10-tetrahydro-3-ni tro-B[a]P . The same adduct was identified from in vitro metabolism of [3H]3-nitro-B[a]P by rat liver microsomes in the presence of calf thymus DNA. A DNA adduct of 3-nitro-B[a]P formed from reaction of N-hydroxy-3-amino-B[a]P, prepared in situ with calf thymus DNA was also isolated. This adduct was identified as 6-(deoxyguanosin-N2-yl)-3-amino-B[a]P. The same adduct was obtained from incubating DNA with 3-nitro-B[a]P in the presence of the mammalian nitroeductase, xanthine oxidase, and hypoxanthine.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7889844

Fu, P P; Herreno-Saenz, D; Von Tungeln, L S; Lay, J O; Wu, Y S; Lai, J S; Evans, F E

1994-01-01

266

Emission of polycyclic aromatic hydrocarbons from medical waste incinerators  

NASA Astrophysics Data System (ADS)

This study was conducted on two batch-type medical waste incinerators (MWIs), including the one with a mechanical grate (MG-MWI) and the other with a fixed grate (FG-MWI) for the disposal of general medical waste and special medical waste, respectively. Both incinerators shared the same air-pollution control devices which were installed in series, including one electrostatic precipitator (ESP) and one wet scrubber (WSB). In addition to the investigated emissions of polycyclic aromatic hydrocarbons (PAHs) from both types of MWIs, the PAH removal efficiencies of air-pollution control devices were also included. In this study, the GC/MS technique was used to analyze the concentrations of 21 PAH species contained in the stack flue gas, ESP fly ash, WSB effluent, and incinerating ash. Results show that total-PAHs (i.e., the sum of 21 PAH species) in stack flue gas were dominated by LM-PAHs (i.e., two- to three-ringed PAHs), but in incinerating ash, ESP fly ash and WSB effluent we found that they were dominated by MM-PAHs (i.e., four-ringed PAHs) and HM-PAHs (i.e., five- to seven-ringed PAHs) for both types of MWIs. The above results due to air-pollution control devices used in both types of MWIs had much higher removal efficiencies on both MM-PAHs and HM-PAHs (>78%) than on LM-PAHs (<5%). The emission factors of total-PAHs for MG-MWI (=252,000 ?g/kg-waste) were lower than FG-MWI (=856,000 ?g/kg-waste), which was probably due to more complete combustion involved in the combustion process of the former than the latter. Nevertheless, the above two emission factors were found consistently higher than the only municipal waste incinerator that was located in the same city (=871 ?g/kg-waste, respectively). The above results warrant the need for seeking better technologies for disposing medical waste in the future.

Lee, Wen-Jhy; Liow, Ming-Chu; Tsai, Perng-Jy; Hsieh, Lien-Te

267

Aerosol Formation and Growth in Aromatic Hydrocarbon/nitrogen - Systems.  

NASA Astrophysics Data System (ADS)

The formation of atmospheric secondary organic aerosol occurs via the photooxidation of gas-phase emissions, in which low vapor pressure products are converted to the aerosol phase either by homogeneous nucleation of new particles or by condensation onto existing particles. One of the goals in studying aerosol dynamics in atmospheric systems is to determine the factors that govern which of these two pathways dominates in the conversion of gas-phase species to the aerosol phase. We have conducted a series of experiments to study the physics of atmospheric organic aerosol formation. An outdoor smog chamber was used to study the formation and growth of secondary aerosol resulting from the photooxidation of aromatic hydrocarbons (toluene, m-xylene, ethylbenzene, and 1,3,5-trimethylbenzene) in the presence of NO _{rm x}. Particular emphasis was given to the effect of primary aerosol on the subsequent aerosol evolution in the system. We observed that with a sufficient number concentration of initial particles in the system, nucleation could be suppressed and all gas -to-particle conversion occurred via condensation onto the seed particles. Average aerosol yields by mass from the gas phase were found to be between 2 and 5%. Several models were used to describe the observed aerosol dynamics. An integral model assuming a monodisperse aerosol was used to determine apparent saturation vapor pressures of condensible species from the observations of nucleation events. Overall predictions of final number concentrations based on these saturation vapor pressures were fairly close to the experimentally observed number concentrations. An analysis of the rate of aerosol growth was carried out for those experiments exhibiting uniform condensational growth. This analysis provided estimates for the gas-phase partial pressures of the condensible species, which could be compared with the integral model vapor pressures to give approximate saturation ratios during these periods of growth. Full aerosol size distribution simulations were performed using the sectional model ESMAP (Warren and Seinfeld, 1985a). Predicted number concentrations were higher than those of the integral model, since the condensation rate on a polydisperse aerosol is smaller than that on a monodisperse distribution, leading to a higher nucleation rate. Comparisons of predicted and observed size distributions during the course of each experiment were limited in accuracy by the numerical diffusion associated with current versions of the sectional model.

Stern, Jennifer E.

268

Polycyclic aromatic hydrocarbons in the South American environment.  

PubMed

Pollution of the environment with polycyclic aromatic hydrocarbons (PAHs) should be a global concern, especially in urbanized areas. In South American countries, where notable increase in urban populations has been observed in the past few years, reliable information about the pollution status of these urban environments is not always easily accessible, and therefore an effort to collect updated information is required. This review attempts to contribute by analyzing the existing information regarding environmental levels of PAHs in some South American countries. A regional trend for environmental PAH information is an uneven contribution, because some countries, such as Bolivia, Peru, Paraguay, and Ecuador, have reported no information at all in the scientific literature, reflecting to a certain extent the different patterns of economic, technical, and scientific development. PAH air monitoring is one of the areas that has received the most attention during the last few years, mainly in Brazil, Chile, and Argentina, where data represent a few geographical areas within the region. PAH levels in air from some urban areas in Argentina, Brazil, and Chile, considered moderate to high (100-1000ng/m3), are probably among the highest values reported in the open literature. Urbanization, vehicle pollution, and wood fires are the principal contributors to the high reported levels. In more temperate areas, a clear distinction is observed between summer and winter levels. PAH monitoring in soils is very limited within the region, with few data available, and most information indicates widespread pollution. In Brazil, values for many representative ecosystems were found. In Chile, data from forestry and agricultural areas indicate in general low concentrations, in spite of a relatively high detection frequency. Pollution levels in soils are highly dependent on their closeness to PAH sources and certain cultural practices (agricultural burnings, forest fires, etc.). Water PAH levels are rarely reported in the scientific literature for South American countries. Few data were available, even though many regulatory agencies perform routine analysis of hydrocarbons in waters. No information was found specifically related to PAH compounds, which could indicate generally low PAH levels in waters. Regional PAH information for sediments also indicates higher levels. Overall, as observed for water, sediment data indicate a complex situation in densely populated areas affected by urban-industrial inputs where high PAH levels are found. In contrast, in remote areas a typical profile of diagenetic PAHs dominates. Concentrations are greatly variable and are principally related to several highly contaminated sites in Argentina and Brazil (hot spots) with levels four to five orders of magnitude higher. Even though PAHs have carcinogenic properties, little attention has been paid to the analysis of aquatic organisms except in the case of bivalves. As observed for other environmental receptors, the regional data distribution is uneven and is heavily centered in coastal environments and in a few countries (Argentina, Brazil, Chile, and Peru). The most comprehensive PAH monitoring program in the South American coastal environment is the Mussel Watch. Baseline PAH concentrations range from 200 to 700 microg kg(-1) lipids in unpolluted sites; from 1,000 to 3,000 microg kg(-1) in moderately contaminated sites; and from 4,000 to 13,000 microg/kg lipids in the most affected bivalves that come from areas of Río de la Plata (Argentine side), Recife (Brazil), and Punta Arenas (Chile). Critical data gaps exist with respect to PAH analysis in biota, including humans, in foodstuffs, and subsequent effects. Considering the high levels reported in the air compartment, risk assessment procedures in highly populated areas need to be performed. Additionally, few countries within the region have information on PAH levels. In these countries, this type of analysis needs to be performed, and the laboratory capacity needs to be built to assure the accomplishment of these

Barra, Ricardo; Castillo, Caroline; Torres, Joao Paulo Machado

2007-01-01

269

Production of aromatic hydrocarbons through catalytic pyrolysis of 5-Hydroxymethylfurfural from biomass.  

PubMed

Catalytic pyrolysis of 5-Hydroxymethylfurfural (HMF) was conducted on a fixed bed reactor at atmospheric pressure. HMF could be converted into aromatic hydrocarbons through catalytic pyrolysis. The catalysts and reaction conditions were both critical in maximizing the aromatic hydrocarbons selectivity. Four catalysts, ?-zeolite, HZSM-5, Ga/HZSM and In/HZSM were tested in this study. HZSM-5 (Si/Al=50) was found to be the most effective catalyst in both reactivity and selectivity among these catalysts. Under the reaction temperature of 600 °C, the highest carbon yield of 48.99% of aromatic hydrocarbons was achieved from catalytic pyrolysis HMF with HZSM-5 (Si/Al=50) as catalyst. Moreover, the HZSM-5 (Si/Al=50) catalyst was recycled for five times without shown deactivation of the catalyst. PMID:23994304

Zhao, Yan; Pan, Tao; Zuo, Yong; Guo, Qing-Xiang; Fu, Yao

2013-11-01

270

Modelling study of electron-beam polycyclic and nitro-polycyclic aromatic hydrocarbons treatment  

NASA Astrophysics Data System (ADS)

The efficiency of the electron-beam removal of harmful impurities from industrial flue gases was studied as applied to polycyclic and nitro-polycyclic aromatic hydrocarbons. The mathematical model of radiation-induced processes was proposed. The model includes aromatic molecules decomposition in gas-phase reactions, and their liquid-phase conversion in the aerosol droplets produced upon the binary volume condensation of water and sulfuric acid vapors. The presence of active species (atoms and radicals) in radiation zone and their reactions with aliphatic and aromatic hydrocarbons can result in an opposite effect: the formation of aromatic molecules and growth of their structure. Modelling study of such processes allows evaluating the efficiency of this purification technology at various initial conditions. Results of calculations are compared with available experimental data.

Gerasimov, Gennady

2007-01-01

271

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

272

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 Central

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

273

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

274

Standard Chemical Thermodynamic Properties of Polycyclic Aromatic Hydrocarbons and Their Isomer Groups I. Benzene Series  

Microsoft Academic Search

The polycyclic aromatic hydrocarbons can be organized into an infinite number of series in each of which successive isomer groups differ by C4H2. The first series starts with benzene, and chemical thermodynamic tables are presented here for C6H6, C10H8, C14H10, C18H12, C22H14, and C26H16 in the ideal gas phase. Since chemical thermodynamic properties are known for only several polycyclic aromatic

Robert A. Alberty; Andrea K. Reif

1988-01-01

275

Molecular cloning of novel genes for polycyclic aromatic hydrocarbon degradation from Commamonas testosteroni GZ39  

SciTech Connect

The mechanisms by which bacteria degrade simple polycyclic aromatic compounds have been studied for some time. The genes for the initial steps in the degradation of maphthalene have been cloned from many different Pseudomonas stains. This study was undertaken to investigate the diversity of genes involved in phenanthrene degradation and to identify novel organisms and genes for polycyclic aromatic hydrocarbon degradations. 53 refs., 5 figs., 1 tab.

Goyal, A.K.; Zylstra, G.J. [Rutgers Univ., New Brunswick, NJ (United States)

1996-01-01

276

Modelling study of electron-beam polycyclic and nitro-polycyclic aromatic hydrocarbons treatment  

Microsoft Academic Search

The efficiency of the electron-beam removal of harmful impurities from industrial flue gases was studied as applied to polycyclic and nitro-polycyclic aromatic hydrocarbons. The mathematical model of radiation-induced processes was proposed. The model includes aromatic molecules decomposition in gas-phase reactions, and their liquid-phase conversion in the aerosol droplets produced upon the binary volume condensation of water and sulfuric acid vapors.

Gennady Gerasimov

2007-01-01

277

Polycyclic Aromatic Hydrocarbon Exposure, Obesity and Childhood Asthma in an Urban Cohort  

PubMed Central

Background Exposure to traffic-related air pollutants, including polycyclic aromatic hydrocarbons (PAHs) from traffic emissions and other combustion sources, and childhood obesity, have been implicated as risk factors for developing asthma. However, the interaction between these two on asthma among young urban children has not been studied previously. Methods Exposure to early childhood PAHs was measured by two week residential indoor monitoring at age 5–6 years in the Columbia Center for Children's Environmental Health birth cohort (n=311). Semivolatile [e.g., methylphenanthrenes] and nonvolatile [e.g., benzo(a)pyrene] PAHs were monitored. Obesity at age 5 was defined as a body mass index (BMI) greater than or equal to the 95th percentile of the year 2000 age- and sex- specific growth charts (Center for Disease Control). Current asthma and recent wheeze at ages 5 and 7 were determined by validated questionnaires. Data were analyzed using a modified Poisson regression in generalized estimating equations (GEE) to estimate relative risks (RR), after adjusting for potential covariates. Results Neither PAH concentrations or obesity had a main effect on asthma or recent wheeze. In models stratified by presence/absence of obesity, a significant positive association was observed between an interquartile range (IQR) increase in natural log-transformed 1-methylphenanthrene (RR [95% CI]: 2.62 [1.17–5.88] with IQRln=0.76), and 9-methylphenanthrene (2.92 [1.09–7.82] with IQRln=0.73) concentrations and asthma in obese children (n=63). No association in non-obese (n=248) children was observed at age 5 (Pinteraction < 0.03). Similar associations were observed for 3-methylphenanthrene, 9-methylphenanthrene, and 3,6-dimethylphenanthrene at age 7. Conclusions Obese young children may be more likely to develop asthma in association with greater exposure to PAHs, and methylphenanthrenes in particular, than non-obese children. PMID:24407477

Jung, Kyung Hwa; Perzanowski, Matthew; Rundle, Andrew; Moors, Kathleen; Yan, Beizhan; Chillrud, Steven N.; Whyatt, Robin; Camann, David; Perera, Frederica P.; Miller, Rachel L.

2014-01-01

278

Distribution of pesticides and polycyclic aromatic hydrocarbons in house dust as a function of particle size.  

PubMed Central

House dust is a repository for environmental pollutants that may accumulate indoors from both internal and external sources over long periods of time. Dust and tracked-in soil accumulate most efficiently in carpets, and the pollutants associated with dust and soil may present an exposure risk to infants and toddlers, who spend significant portions of their time in contact with or in close proximity to the floor and who engage in frequent mouthing activities. The availability of carpet dust for exposure by transfer to the skin or by suspension into the air depends on particle size. In this study, a large sample of residential house dust was obtained from a commercial cleaning service whose clients were homeowners residing in the Raleigh-Durham-Chapel Hill (Research Triangle) area of North Carolina. The composite dust was separated into seven size fractions ranging from < 4 to 500 microm in diameter, and each fraction was analyzed for 28 pesticides and 10 polycyclic aromatic hydrocarbons (PAHs). Over 20% of the fractionated dust sample consisted of particles < 25 microm in diameter. Fourteen pesticides and all 10 of the target PAHs were detected in one or more of the seven size-fractionated samples. Sample concentrations reported range from 0.02 to 22 microg/g; the synthetic pyrethroids cis- and trans-permethrin were the most abundant pesticide residue. The concentrations of nearly all of the target analytes increased gradually with decreasing particle size for the larger particles, then increased dramatically for the two smallest particle sizes (4-25 microm and < 4 microm). Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:10464072

Lewis, R G; Fortune, C R; Willis, R D; Camann, D E; Antley, J T

1999-01-01

279

Determination of total and polycyclic aromatic hydrocarbons in aviation jet fuel.  

PubMed

The aviation jet fuel widely used in turbine engine aircraft is manufactured from straight-run kerosene. The combustion quality of jet fuel is largely related to the hydrocarbon composition of the fuel itself; paraffins have better burning properties than aromatic compounds, especially naphthalenes and light polycyclic aromatic hydrocarbons (PAHs), which are characterised as soot and smoke producers. For this reason the burning quality of fuel is generally measured as smoke fermation. This evaluation is carried out with UV spectrophotometric determination of total naphthalene hydrocarbons and a chromatographic analysis to determine the total aromatic compounds. These methods can be considered insufficient to evaluate the human health impact of these compounds due to their inability to measure trace (ppm) amounts of each aromatic hyrcarbon and each PAH in accordance with limitations imposed because of their toxicological properties. In this paper two analytical methods are presented. Both are based on a gas chromatographic technique with a mass detector operating in be selected ion monitoring mode. The first method was able to determine more than 60 aromatic hydrocarbons in a fuel sample in a 35-min chromatographic run, while the second was able to carry out the analysis of more than 30 PAHs in a 40-min chromatographic run. The linearity and sensitivity of the methods in measuring these analytes at trace levels are described. PMID:12580487

Bernabei, M; Reda, R; Galiero, R; Bocchinfuso, G

2003-01-24

280

Comprehensive two-dimensional high-performance liquid chromatography for the separation of polycyclic aromatic hydrocarbons.  

PubMed

A comprehensive two-dimensional HPLC system for the separation of polycyclic aromatic hydrocarbons was developed using a pentabromobenzyl column as the first dimension and two short monolithic C18 columns as the second dimension. The primary column and two secondary columns were coupled by a 10-port 2-position valve. The effluent from the first dimension was repetitively injected into the second dimension every 12 s. Due to its resolution, this technique is a powerful tool for the separation of polycyclic aromatic hydrocarbons in a complex matrix such as environmental samples. PMID:12866876

Murahashi, Tsuyoshi

2003-06-01

281

Indirect- and direct-acting mutagenicity of diesel, coal and wood burning-derived particulates and contribution of polycyclic aromatic hydrocarbons and nitropolycyclic aromatic hydrocarbons.  

PubMed

Particulates exhausted from two types of diesel engines (DEPs), burning-derived particulates from three types of coal (CBPs) and burning-derived particulates from three types of wood (WBPs) were separated into four fractions by silica-gel column chromatography using n-hexane, n-hexane-dichloromethane (3:1, v/v), dichloromethane and methanol, as the corresponding eluents. The indirect-acting mutagenicity of each fraction was assayed by the Ames test using the Salmonella typhimurium TA100 strain with S9 mix and the direct-acting mutagenicity was assayed using the S. typhimurium TA98 strain without S9 mix. The polycyclic aromatic hydrocarbons (PAHs) and nitropolycyclic aromatic hydrocarbons (NPAHs) of each fraction were determined by high-performance liquid chromatography (HPLC). Both direct- and indirect-acting of mutagenicities were the highest in samples of DEPs. The contributions of PAHs in samples of WBPs and NPAHs in DEPs were the largest, respectively. PMID:19896557

Yang, Xiao-Yang; Igarashi, Kazuhiko; Tang, Ning; Lin, Jin-Ming; Wang, Wei; Kameda, Takayuki; Toriba, Akira; Hayakawa, Kazuichi

2010-01-01

282

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

283

Kinetics of Hydrogen Abstraction Reactions from Polycyclic Aromatic Hydrocarbons by H Angela Violi,*, Thanh N. Truong, and Adel F. Sarofim  

E-print Network

, 2004 An application of the Reaction Class Transition State Theory/Linear Energy Relationship (RC Polycyclic Aromatic Hydrocarbons (PAH). Two classes of reactions have been considered, namely hydrogen bondedKinetics of Hydrogen Abstraction Reactions from Polycyclic Aromatic Hydrocarbons by H Atoms Angela

Truong, Thanh N.

284

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...

285

Determination of polynuclear aromatic hydrocarbons present in asphaltenes from Mexican oil. A possible environmental risk.  

PubMed

A supercritical fluid extraction and HPLC analysis of the asphaltenes derived from Mexican oil was performed. The aim was to identify potentially mutagenic polynuclear aromatic hydrocarbons present in asphaltenes, since roof waterproofing applications in this country present a significant exposure to hot asphaltene vapors that might conceivably carry such toxic hydrocarbons and therefore pose a health hazard to the workers who apply molten asphaltenes. PMID:8555743

Dieck, T; Acosta, A S; Villegas-Navarro, A

1995-01-01

286

Separation of polycyclic aromatic hydrocarbons by liquid chromatography on cross-linked polyvinylpyrrolidone.  

PubMed

Polycyclic aromatic hydrocarbons (PAHs) can be separated by liquid chromatography on cross-linked polyvinylpyrrolidone (PVP) stationary phase using a polar solvent as eluent. The order of elution is determined primarily by the number of condensed aromatic rings Efficient separations were obtained with a column packed with 63-90 mum particles of PVP and isopropanol as eluent. Capacity factors (k') ranged from 0.3-10 for PAHS having from one to five aromatic rings, and theoretical plate heights were between 0.3 and 0.5 mm. This technique is being used to assist in the characterization of products from coal liquifaction processes. PMID:1002808

Goldstein, G

1976-12-22

287

Polycyclic Aromatic Hydrocarbons in an industrialized urban area  

NASA Astrophysics Data System (ADS)

Urbanization, agricultural intensification and industrialization are contributing to erosion, local and diffuse contamination and sealing of soil surfaces, resulting in soil quality degradation. Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in urban environments and considered good markers of anthropogenic activities such as traffic, industry, domestic heating and agriculture. Although they are subject to biodegradation and photodegradation, once in the soil, they tend to bind to the soil organic fraction. Estarreja is a small coastal town in the Northwestern Portuguese coast, with a close relation with the lagoon of Aveiro which supports a variety of biotopes (channels, islands with vegetation, mudflats, salt marshes and agricultural fields) of important ecological value. It supports an intensive and diversified agriculture, a variety of heavy and light industries and a population of about half a million people which is dependent on this resource. This is a very industrialized area, due to its five decades of chemical industry. This study aims to assess the impact of the urbanization and of the chemical industry in PAHs distribution. The survey and sampling method were based on pre-interpreted maps, aerial photographs, and directly checked in the field, in order to get an overall characterization of the area. Topsoils were collected from 34 sites, considering different land uses. Five land uses were chosen: ornamental gardens, parks, roadsides, forest and agricultural. Parameters such as soil pH (ISO method 10390:1994), total C, N, H, S percentages (microanalyser LECO, CNHS-932), organic matter (LOI at 430°), particle size distribution (Micromeritics® Sedigraph 5100), cation exchange capacity and exchangeable bases, were determined in order to have a general characterization of soil. Determination of the 16 EPA PAHs in soils was performed by GC/MS after a Soxhlet extraction and an alumina clean-up of extracts. Procedure blanks, duplicates and reference material were used in each extraction batch for quality control assessment. In what concerns the general parameters, Estarreja soils were characterized as slightly acid, with a median pHCaCl2 of 5.15, ranging from 3.12 and 6.88. The content in organic matter observed was relatively high, with a median of 4.6% and ranging from 1.8 to 45%. The median concentration of PAHs was 98 µg kg-1, ranging from 27 to 2,016 µg kg-1. The former value was found in an agricultural area and, together with another agricultural soil (with 1121 µgPAHs/kg), were considered heavily contaminated according to the classification given by Maliszewska-Kordybach. Moreover, eight samples were classified as weakly contaminated (PAHs between 200 and 600 µg/kg) and the remaining ones were not contaminated. The relative abundance of individual PAHs in Estarreja soils was evaluated, being the most abundant Fluoranthene and Pyrene followed by Benzo(b)fluoranthene, Phenanthrene and Crysene. These PAHs are the ones usually associated with the combustion of fossil fuel and other burnable materials, being this composition is typical for topsoil of European industrialized countries. Geostatistical methods were used to show the spatial variability of contaminants and the probability of exceeding the risk-based standards. The plots of concentration of PAHs on GIS highlight areas where the highest elements concentrations occur and the land use associated. These soil maps assemble important information for decision-making, allowing identifying possible sources of contamination, assess the suitability of soil to its use and to contribute for land use planning in accordance to soil characteristics. Acknowledgements: This work was supported by the Portuguese Foundation for Science and Technology (SFRH/BD/38418/2007) and by CESAM

Cachada, A.; Pereira, R.; Ferreira da Silva, E.; Duarte, A. C.

2009-04-01

288

Peat fires as source of polycyclic aromatic hydrocarbons in soils  

NASA Astrophysics Data System (ADS)

Polycyclic aromatic hydrocarbons (PAHs) arrive from pyrogenic sources including volcanism and the combustion of oil products and plant materials. The production of PAHs during the combustion of plant materials was considered in a number of publications, but their results were mainly obtained in laboratory experiments. Insufficient data are available on the hightemperature production of PAHs in environmental objects. For example, natural fires are frequently related to the PAH sources in landscapes, but very little factual data are available on this topic. On Polistovskii reserve (Russia, Pskov region) the soil series were separated depending on the damage to the plants; these series included soils of plots subjected to fires of different intensities, as well as soils of the background plots. The series of organic and organomineral soils significantly differed in their PAH distributions. In this series, the concentration of PAHs in the upper horizons of the peat soils little varied or slightly decreased, but their accumulation occurred at a depth of 5-10 or 10-20 cm in the soils after the fires. For example, in the series of high moor soils, the content of PAHs in the upper horizons remained almost constant; significant differences were observed in the subsurface horizons: from 2 ng/g in the background soil to 70 ng/g after the fire. In the upper horizons of the oligotrophic peat soils under pine forests, the total PAH content also varied only slightly. At the same time, the content of PAHs in the soil series increased from 15 to 90 ng/g with the increasing pyrogenic damage to the plot. No clear trends of the PAH accumulation were recorded in the organomineral soils. The content of PAHs in the soddy-podzolic soil subjected to fire slightly decreased (from 20 to 10 ng/g) compared to the less damaged soil. In peat fires, the access of oxygen to the fire zone is lower than in forest fires. The oxygen deficit acts as a factor of the organic fragments recombination and PAH production; therefore, larger amounts of PAHs are formed in peat fires. In addition, the peat fires occur directly in the soil layer; therefore, larger amounts of the resulting polyarenes remain in the soils of the fire sites. PAHs also can be formed at the heating of organic matter on the areas adjacent to the fire sites. After the combustion of peat in fires, phenanthrene, chrysene, benz[a]pyrene, and tetraphene accumulate in soils. This is mainly the group of 4-nuclear compounds with the participation of 3-nuclear phenanthrene and 5-nuclear benz[a]pyrene. The formation of high-molecular weight compounds like benz[a]pyrene and, in some places, benzo[ghi]perylene is possible during smoldering under a low oxygen supply.

Tsibart, Anna

2013-04-01

289

Microbial degradation of polycyclic aromatic hydrocarbons: effect of substrate availability on bacterial growth kinetics  

Microsoft Academic Search

It is demonstrated that bacterial growth on crystalline or adsorbed polycyclic aromatic hydrocarbons can result in a linear increase in biomass concentration. A simple mathematical approach is presented, showing that under these circumstances mass transfer from the solid phase to the liquid phase is rate-limiting for growth.

F. Volkering; A. M. Breure; A. Sterkenburg; J. G. van Andel

1992-01-01

290

Effects of aqueous chemistry on the binding of polycyclic aromatic hydrocarbons by dissolved humic materials  

Microsoft Academic Search

The influence of solution chemistry on the binding of three polycyclic aromatic hydrocarbons (PAHs) by well-characterized humic material (Suwannee River humic and fulvic acid) was examined by using fluorescence quenching techniques. The experiments show that binding is complete within 3 min and that the fluorescence of PAH compounds associated with the humic substances is fully quenched as evidenced by quantum

Mark A. Schlautman; James J. Morgan

1993-01-01

291

Survey of polycyclic aromatic hydrocarbons in canned bivalves and investigation of their potential sources  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous contaminants in the marine environment derived from uncontrolled petroleum spills, marine transports, discharges from ships, and urban runoff. The NW coast of Spain (Galicia) has a characteristic hydrography, defined by a continuous suite of estuarine systems called “Rías Gallegas”. Some of these estuaries support important industrial and urban centres while others are preserved from

Ledicia Rey-Salgueiro; Elena Martínez-Carballo; Mercedes Sonia García-Falcón; Jesús Simal-Gándara

2009-01-01

292

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

293

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

294

Gene biomarkers in diatom Thalassiosira pseudonana exposed to polycyclic aromatic hydrocarbons from contaminated marine surface sediments  

Microsoft Academic Search

Marine diatoms have a key role in the global carbon fixation and therefore in the ecosystem. We used Thalassiosira pseudonana as a model organism to assess the effects of exposure to environmental pollutants at the gene expression level. Diatoms were exposed to polycyclic aromatic hydrocarbons mixture (PAH) from surface sediments collected at a highly PAH contaminated area of the Mediterranean

Raquel N. Carvalho; Alina D. Burchardt; Fabrizio Sena; Giulio Mariani; Anne Mueller; Stephanie K. Bopp; Gunther Umlauf; Teresa Lettieri

2011-01-01

295

Trace elements and polycyclic aromatic hydrocarbons (PAHs) concentrations in deep Gulf of Mexico sediments  

Microsoft Academic Search

The concentrations of polycyclic aromatic hydrocarbons (PAHs) and trace elements were determined for surface (top 2cm) sediment samples collected during the deep Gulf of Mexico benthos (DGoMB) study .These elements and compounds are known to be toxic to organisms at high concentrations and may affect biological communities. There is no indication of major anthropogenic input of the elements Be, Co,

Terry L. Wade; Yousra Soliman; Stephen T. Sweet; Gary A. Wolff; Bobby J. Presley

2008-01-01

296

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.

297

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.

298

METHOD DEVELOPMENT AND MONITORING OF POLYNUCLEAR AROMATIC HYDROCARBONS IN SELECTED U.S. WATERS  

EPA Science Inventory

A method for concentration of trace quantities of the six representatives of polynuclear aromatic hydrocarbon (PAH) family has been developed and successfully applied to PAH monitoring in finished and raw waters. PAH are collected by passing water through polyurethane foam plugs....

299

Infrared Spectroscopy of Matrix-Isolated Polycyclic Aromatic Hydrocarbon Ions. 5. PAHs Incorporating a Cyclopentadienyl Ring  

E-print Network

Infrared Spectroscopy of Matrix-Isolated Polycyclic Aromatic Hydrocarbon Ions. 5. PAHs, California 94802 ReceiVed: NoVember 5, 1999; In Final Form: February 9, 2000 The matrix-isolation technique, the matrix-isolation technique has proven particularly well suited to the study of both the cat- ions3b,5a

300

Bacterial biodegradation of polycyclic aromatic hydrocarbons (PAH) and potential effects of surfactants on PAH bioavailability  

SciTech Connect

The purposes of this project were to evaluate whether indigenous microorganisms from polycyclic aromatic hydrocarbons (PAH)-contaminated soils produce surfactants (biosurfactants) as a means of enhancing the bioavailability of PAH; to improve the understanding of the general physiology of a diverse group of PAH-degrading bacteria; and to study in general how surfactants influence the biodegradation of hydrophobic chemicals.

Aitken, M.D.; Grimberg, S.J.; Nagel, J.; Nagel, R.D.; Stringfellow, W.T.

1996-02-01

301

Sexual Maturation in Relation to Polychlorinated Aromatic Hydrocarbons: Sharpe and Skakkebaek's Hypothesis Revisited  

Microsoft Academic Search

Polychlorinated aromatic hydrocarbons (PCAHs) have been described as endocrine disruptors in animals and in accidentally or occupationally exposed humans. In the present study we examined the effect of moderate exposure to PCAHs on sexual maturation. Two hundred adolescents (mean age, 17.4 years) who resided in two polluted suburbs and a rural control area in Flanders (Belgium) participated. We measured the

Elly Den Hond; Harry A. Roels; Karel Hoppenbrouwers; Tim Nawrot; Lutgarde Thijs; Corinne Vandermeulen; Gerhard Winneke; Dirk Vanderschueren; Jan A. Staessen

2002-01-01

302

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...

303

Fluorescence, Absorption, and Excitation Spectra of Polycyclic Aromatic Hydrocarbons as a Tool for Quantitative Analysis  

ERIC Educational Resources Information Center

A quantitative and qualitative study of the interplay between absorption, fluorescence, and excitation spectra of pollutants called polycyclic aromatic hydrocarbons (PAHs) is conducted. The study of five PAH displays the correlation of the above-mentioned properties along with the associated molecular changes.

Rivera-Figueroa, A. M.; Ramazan, K. A.; Finlayson-Pitts, B. J.

2004-01-01

304

Applications and New Developments in Fluorescence Spectroscopic Techniques for the Analysis of Polycyclic Aromatic Hydrocarbons  

Microsoft Academic Search

Carcinogenic, mutagenic and the toxic nature of polycyclic aromatic hydrocarbons (PAHs) make them of current interest for environmental monitoring. Recent progress in the use of a fiber optic wave-guide for remote sensing and inexpensive laser sources to enhance sensitivity has made fluorescence techniques rich for PAHs classification and estimation. This is further boosted by multiparametric information e.g., spectral change, intensity,

Digambara Patra

2003-01-01

305

PERSONAL EXPOSURES TO POLYCYCLIC AROMATIC HYDROCARBONS ASSOCIATED WITH THE NHEXAS PILOT  

EPA Science Inventory

Personal exposure monitoring for select polycyclic aromatic hydrocarbons (PAHs) was performed as part of the National Human Exposure Assessment Survey (NHEXAS) Pilot Study in Baltimore, MD. Twenty-four hour PM10 sample collections (~5.7 m3) were performed using personal envi...

306

SAR Models for Estimating the Percutaneous Absorption of Polynuclear Aromatic Hydrocarbons  

Microsoft Academic Search

A structure-activity relationship (SAR) of the in vitro percutaneous absorption of polycyclic aromatic hydrocarbons (PAH) is described. The data set consisted of 60 three to seven ring PAH. Over 50 numeric descriptors were generated from the modeled molecular structures. Computer aided methods were used to evaluate descriptors and develop linear expressions relating the percent of dermally applied PAH dose absorbed

T. A. Roy; A. J. Krueger; C. R. Mackerer; W. Neil; A. M. Arroyo; J. J. Yang

1998-01-01

307

Concentrations of particulate airborne polycyclic aromatic hydrocarbons and metals collected in Lahore, Pakistan  

Microsoft Academic Search

Hi-vol air sampling equipment was run at three sites (representative of “city”, “industrial” and “rural” sampling locations) in Lahore, Pakistan, for over a year. The extraction and quantitative analyses of all Lahore air samples was completed for a suite of metals, various anions, ammonium, elemental and organic carbon, as well as particle-associated polycyclic aromatic hydrocarbons (PAHs). A comparison of Lahore

D. J. T. Smith; Roy M. Harrison; L. Luhana; Casimiro A. Pio; L. M. Castro; Mohammad Nawaz Tariq; S. Hayat; T. Quraishi

1996-01-01

308

MEASUREMENTS OF POLYCYCLIC AROMATIC HYDROCARBONS IN AMBIENT AIR PARTICULATES IN NORTHERN NEW ENGLAND  

EPA Science Inventory

The paper gives results of measuring polycyclic aromatic hydrocarbons (PAHs) in ambient air particulates in Northern New England. Standard high-volume filter samples of ambient-air particulates were collected during several heating seasons in a semi-rural village, a rural area, a...

309

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

310

Hybrid membranes of metal-organic molecule nanocages for aromatic/aliphatic hydrocarbon separation by pervaporation.  

PubMed

Hybrid membranes composed of porous metal-organic molecule nanocages as fillers embedded in a hyperbranched polymer (Boltorn W3000) were fabricated, which exhibit excellent pervaporation separation performances towards aromatic/aliphatic hydrocarbons. The unique nature of the molecule-based fillers and their good dispersion and compatibility in/with the polymer are responsible for the good membrane properties. PMID:25260031

Zhao, Cui; Wang, Naixin; Wang, Lin; Huang, Hongliang; Zhang, Rong; Yang, Fan; Xie, Yabo; Ji, Shulan; Li, Jian-Rong

2014-11-21

311

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

312

ANALYSIS OF POLYCYCLIC AROMATIC HYDROCARBONS BY ION TRAP TANDEM MASS SPECTROMETRY  

EPA Science Inventory

An ion-trap mass spectrometer with a wave board and tandem mass spectrometry software was used to analyze gas chromatographically separated polycyclic aromatic hydrocarbons (PAHs) by using collision-induced dissociation (CID). The nonresonant (multiple collision) mode was used to...

313

Assessment of the dietary habits and polycyclic aromatic hydrocarbon exposure in primary school children  

Microsoft Academic Search

Thirty Italian children, 7–9 year aged, living in Naples were investigated on their dietary habits and on polycyclic aromatic hydrocarbon (PAH) exposure by a food diary-questionnaire and one week duplicate diet sample analyses. Daily total food consumption mean value was 632 ± 215 g day, median value 613 g day. The daily energy intake and the diet composition meanly agreed

T. Cirillo; P. Montuori; P. Mainardi; I. Russo; E. Fasano; M. Triassi; R. Amodio-Cocchieri

2010-01-01

314

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

315

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

316

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

317

Particle in a Disk: A Spectroscopic and Computational Laboratory Exercise Studying the Polycyclic Aromatic Hydrocarbon Corannulene  

ERIC Educational Resources Information Center

This laboratory exercise introduces undergraduate chemistry majors to the spectroscopic and theoretical study of the polycyclic aromatic hydrocarbon (PAH), corannulene. Students explore the spectroscopic properties of corannulene using UV-vis and Raman vibrational spectroscopies. They compare their experimental results to simulated vibrational…

Frey, E. Ramsey; Sygula, Andrzej; Hammer, Nathan I.

2014-01-01

318

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...

319

MATERNAL TRANSFER OF BIOACTIVE POLYCHLORINATED AROMATIC HYDROCARBONS IN SPAWNING CHINOOK SALMON (ONCORHYNCHUS TSCHAWYTSCHA)  

EPA Science Inventory

The biological potency (relative to 2,3,7,8-tetrachlorodibenzo-p-dioxin, TCDD) of planar polychlorinated aromatic hydrocarbons (PCHs) in extracts of eggs and flesh from spawning female chinook salmon (Oncorhynchus tschawytscha) from Lake Michigan was determined by measuring the i...

320

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

321

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

USGS Publications Warehouse

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

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

2011-01-01

322

Native polycyclic aromatic hydrocarbons (PAH) in coals – A hardly recognized source of environmental contamination  

Microsoft Academic Search

Numerous environmental polycyclic aromatic hydrocarbon (PAH) sources have been reported in literature, however, unburnt hard coal\\/ bituminous coal is considered only rarely. It can carry native PAH concentrations up to hundreds, in some cases, thousands of mg\\/kg. The molecular structures of extractable compounds from hard coals consist mostly of 2–6 polyaromatic condensed rings, linked by ether or methylene bridges carrying

C. Achten; T. Hofmann

2009-01-01

323

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

324

Polycyclic aromatic hydrocarbons in water and sediment of the Baltic Sea  

Microsoft Academic Search

Between 1992 and 1994, the distribution of 15 polycyclic aromatic hydrocarbons (PAHs) was investigated in seawater and surface sediments of the Baltic Sea. The analysis of PAHs in seawater is very difficult due to the low concentration. High separation capability is required. A method for analysing very low concentrations of PAHs is presented. The method is based on the high-performance

G. Witt

1995-01-01

325

APPLICATION OF EPA METHOD 610 TO THE ANALYSIS OF POLYNUCLEAR AROMATIC HYDROCARBONS IN LEACHATE SAMPLES  

EPA Science Inventory

This report summarizes the results of a spiking study performed on a sanitary landfill leachate matrix. Fifteen polynuclear aromatic hydrocarbons (PNAs) were dosed into the landfill leachate and analyzed using EPA Method 610. The results show that the PNAs containing two, three, ...

326

Aromatic hydrocarbons in distillate cuts of crude oils from new fields of Belorussia  

Microsoft Academic Search

In this article we are presenting results from an investigation of the quantitative distribution of aromatic hydrocarbons in the distillate cuts of crude oils from new commercial fields in Belorussia: Zolotukhino (Well 7), Tishkovichi (Well 95), and Barsukovsk (Well 9). The distribution of low-molecular-weight homologs of benzene in these crude oils had been established previously [i] in a determination of

Yu. G. Egiazarov; V. I. Kulikov; A. M. Smol'skii; E. B. Barkovskaya

1978-01-01

327

Polycyclic Aromatic Hydrocarbons (PAH) in Abraded Particles of Brake and Clutch Linings  

Microsoft Academic Search

Clutch linings and, in particular, brake linings are subjected to considerable thermal stress. Pyrolytic decomposition of the organic portions of the abraded particles can result from this. The products of such cracking reactions include polycyclic aromatic hydrocarbons (PAH). These substances, some of which are carcinogenic, exhibit distinctly adsorptive properties with respect to chrysotile, which makes up, on average, 30% of

U. Knecht; H. J. Elliehausen; W. Judas; H. J. Woitowitz

1987-01-01

328

Biosurfactants from Acinetobacter calcoaceticus BU03 Enhance the Bioavailability and Biodegradation of Polycyclic Aromatic Hydrocarbons  

Microsoft Academic Search

Biosurfactants produced by an isolated thermophilic strain Acinetobacter calcoaceticus BU03 were demonstrated to be effective in enhancing the solubility of polycyclic aromatic hydrocarbons (PAHs) and the present study aimed at investigating its effectiveness in increasing bioavailability of PAHs in soil for biodegradation under thermophilic composting condition. At 25 times of its critical micelle concentration (CMC), biosurfactants by BU03 significantly increased

Jonathan W. C. Wong; Zhenyong Zhao; Guanyu Zheng

2010-01-01

329

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 ...

330

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 ...

331

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

332

Empirical modeling of soot formation in shock-tube pyrolysis of aromatic hydrocarbons  

NASA Technical Reports Server (NTRS)

A method for empirical modeling of soot formation during shock-tube pyrolysis of aromatic hydrocarbons is developed. The method is demonstrated using data obtained in pyrolysis of argon-diluted mixtures of toluene behind reflected shock waves. The developed model is in good agreement with experiment.

Frenklach, M.; Clary, D. W.; Matula, R. A.

1986-01-01

333

Polycyclic aromatic hydrocarbons affect survival and development of common snapping turtle ( Chelydra serpentina) embryos and hatchlings  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs) are toxic compounds found in the John Heinz National Wildlife Refuge in Philadelphia, Pennsylvania. We assessed the impact of PAHs and crude oil on snapping turtle development and behavior by exposing snapping turtle eggs from the Refuge and from three clean reference sites to individual PAHs or a crude oil mixture at stage 9 of embryonic

Robin J. Van Meter; James R. Spotila; Harold W. Avery

2006-01-01

334

Minimal clean-up and rapid determination of polycyclic aromatic hydrocarbons in instant coffee  

Microsoft Academic Search

The essential aim of this work is the development of a simple, fast, quantitative and economic method for polycyclic aromatic hydrocarbons (PAHs) potentially generated by roasting coffee beans, which is the most important process in the coffee industry for the development of the characteristic flavour of the bean mix. The PAHs were chosen because they differed in the number of

Mercedes Sonia Garc??a-Falcón; Beatriz Cancho-Grande; Jesús Simal-Gándara

2005-01-01

335

Cancer risk from occupational and environmental exposure to polycyclic aromatic hydrocarbons  

Microsoft Academic Search

Epidemiologic evidence on the relationship between polycyclic aromatic hydrocarbons (PAH) and cancer is reviewed. High occupational exposure to PAHs occurs in several industries and occupations. Covered here are aluminum production, coal gasification, coke production, iron and steel foundries, tar distillation, shale oil extraction, wood impregnation, roofing, road paving, carbon black production, carbon electrode production, chimney sweeping, and calcium carbide production.

Paolo Boffetta; Nadia Jourenkova; Per Gustavsson

1997-01-01

336

Factors influencing polycyclic aromatic hydrocarbon distributions in South Carolina estuarine sediments  

Microsoft Academic Search

Surface (2 cm) sediment was collected from three South Carolina estuaries, Winyah Bay, Charleston Harbor and the North Edisto River estuary for a total of 64 samples. The sediment samples were analyzed for 24 individual polycyclic aromatic hydrocarbons (PAHs; two to six rings) by gas chromatography with ion trap mass spectrometric detection. Concentrations of total PAHs were extremely variable, ranging

John R. Kucklick; Scott K. Sivertsen; Marion Sanders; Geoffrey I. Scott

1997-01-01

337

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

E-print Network

Isomer discrimination of polycyclic aromatic hydrocarbons in the Murchison meteorite by resonant;Abstract We have used two-color resonant two-photon ionization (2C-R2PI) mass spectrometry to discriminate demonstrated isomer discrimination of PAHs by chemical ionization mass spectrometry with carbon dioxide

de Vries, Mattanjah S.

338

Genome Sequence of Sphingobium yanoikuyae B1, a Polycyclic Aromatic Hydrocarbon-Degrading Strain  

PubMed Central

Sphingobium yanoikuyae B1 can utilize biphenyl, naphthalene, phenanthrene, toluene, and m-/p-xylene as sole sources of carbon and energy. Here, we present a 5.2-Mb assembly of its genome. An analysis of the genome can provide insights into the mechanisms of polycyclic aromatic hydrocarbon (PAH) degradation and potentially aid in bioremediation applications. PMID:25657282

Zhao, Qiang; Wang, Wei; Peng, Huasong; Zhang, Xuehong

2015-01-01

339

Fungal metabolism of polycyclic aromatic hydrocarbons: past, present and future applications in bioremediation  

Microsoft Academic Search

  This article examines the importance of non-ligninolytic and ligninolytic fungi in the bioremediation of polycyclic aromatic\\u000a hydrocarbon contaminated wastes. The research from the initial studies in Dave Gibson’s laboratory to the present are discussed.

C E Cerniglia

1997-01-01

340

Author's personal copy The sedimentary fluxes of polycyclic aromatic hydrocarbons in the  

E-print Network

in sediment discharge at 480 Mt yr- 1 (Yang et al., 2006). It discharges into the East China Sea (ECS aromatic hydrocarbons (PAHs) in two 210 Pb dated sediment cores from the coastal East China Sea, strongly influenced by the discharge from the Yangtze River, were determined to help to reconstruct the economic

Zheng, Mei

341

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

342

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...

343

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

344

Feed Ingredients Mainly Contributing to Polycyclic Aromatic Hydrocarbon and Polychlorinated Biphenyl Residues  

Microsoft Academic Search

Animal nutrition constitutes an important issue for the animal production industry. Products intended for animal feed may contain undesirable substances which could endanger animal health or, because of their presence in livestock products, human health or the environment. In this sense, several incidents related with the presence of persistent organic pollutants, particularly with polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons

RICARDO FERNÁNDEZ-GONZÁLEZ; IRIA YEBRA-PIMENTEL; ELENA MARTÍNEZ-CARBALLO; JESÚS SIMAL-GÁNDARA

2012-01-01

345

Contamination of polycyclic aromatic hydrocarbons in surface sediments of mangrove swamps  

Microsoft Academic Search

The concentrations of total polycyclic aromatic hydrocarbons (?PAHs) and 15 individual PAH compounds in 20 surface sediments collected from four mangrove swamps in Hong Kong were analysed. ?PAH concentrations ranged from 356 to 11,098 ng g?1 dry weight with mean and median values of 1992 and 1142 ng g?1, respectively. These values were significantly higher than those of marine bottom

N. F. Y Tam; L Ke; X. H Wang; Y. S Wong

2001-01-01

346

Polycyclic aromatic hydrocarbons in soil and air: statistical analysis and classification by the SIMCA method  

Microsoft Academic Search

Soil samples from 12 locations in Norway have been analyzed for 9 polycyclic aromatic hydrocarbons (PAH). The same unsubstituted PAH have been determined in air samples collected near an aluminum reduction plant. Analysis by high-resolution gas chromatography-mass spectroscopy in the selected ion mode showed concentrations in soil ranging from less than 1 ppb (detection limit) to 993 ppb for individual

Nils B. Vogt; Frode Brakstad; Karin Thrane; Svein Nordenson; Jostein Krane; Eli Aamot; Knut Kolset; Kim Esbensen; Eiliv Steinnes

1987-01-01

347

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

348

QSARS FOR PHOTOINDUCED TOXICITY: I. ACUTE LETHALITY OF POLYCYCLIC AROMATIC HYDROCARBONS TO DAPHNIA MAGNA  

EPA Science Inventory

Research with a variety of aquatic species has shown that while polycyclic aromatic hydrocarbons (PAHs) are generally not acutely toxic in conventional laboratory tests, many are extremely toxic in the presence of sunlight. n an effort to develop a model for predicting which PAHs...

349

QSAR ESTIMATED OF EXCITED STATES AND PHOTOINDUCED ACUTE TOXICITY OF POLYCYCLIC AROMATIC HYDROCARBONS  

EPA Science Inventory

Direct calculation of the energy of excited states for polycyclic aromatic hydrocarbons using semi-empirical methods on a supercomputer were inadequate in explaining spectroscopic data or measured phytotoxicity. he energy difference between frontier orbitals HOMO-LUMO gap of "ave...

350

Extraction and recovery of polycyclic aromatic hydrocarbons from environmental solids using supercritical fluids  

Microsoft Academic Search

The use of supercritical fluids for the extraction and recovery of polycyclic aromatic hydrocarbons (PAH) from environmental solids has been developed and tested by using urban dust, fly ash, and river sediment. Supercritical NâO and 5% methanol modifier gave the best recoveries of PAH from all three samples when compared to supercritical COâ with 5% methanol, NâO, COâ, and ethane.

Steven B. Hawthorne; David J. Miller

1987-01-01

351

Mobilization of soil organic matter by complexing agents and implications for polycyclic aromatic hydrocarbon desorption  

Microsoft Academic Search

Complexing agents are frequently used in treatment technologies to remediate soils, sediments and wastes contaminated with toxic metals. The present study reports results that indicate that the rate and extent of soil organic matter (SOM) as represented by dissolved natural organic carbon (DNOC) and polycyclic aromatic hydrocarbon (PAH) desorption from a contaminated soil from a manufactured gas plant (MGP) site

Y Yang; D Ratté; B. F Smets; J. J Pignatello; D Grasso

2001-01-01

352

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...

353

Polycyclic aromatic hydrocarbons in asteroid 2008 TC3: Dispersion of organic compounds inside asteroids  

E-print Network

Polycyclic aromatic hydrocarbons in asteroid 2008 TC3: Dispersion of organic compounds inside asteroids Hassan SABBAH1* , Amy L. MORROW1 , Peter JENNISKENS2 , Muawia H. SHADDAD3 , and Richard N. ZARE1. Among the predominantly polymict ureilite meteorites collected from the impact of asteroid 2008 TC3

Zare, Richard N.

354

SELECTIVE ENUMERATION OF AROMATIC AND ALIPHATIC HYDROCARBON DEGRADING BACTERIA BY A MOST-PROBABLE-NUMBER PROCEDURE  

EPA Science Inventory

A most-portable-number (MPN) procedure was developed to separately enumerate aliphatic and aromatic hydrocarbon degrading bacteria, because most of the currently available methods are unable to distinguish between these two groups. Separate 96-well microtiter plates are used to ...

355

Determination of polycyclic aromatic hydrocarbons in biochar and biochar amended soil  

Technology Transfer Automated Retrieval System (TEKTRAN)

A method for the determination of the 16 USEPA polycyclic aromatic hydrocarbons (PAHs) in biochar and soil amended with biochar was developed. Samples were Soxhlet extracted with acetone:cyclohexane 1:1, and PAHs were analysed by GC-MS after silica gel clean-up. In a comparative study based on reflu...

356

Formation mechanism for polycyclic aromatic hydrocarbons in methane flames  

E-print Network

applications including heating systems and gas turbines for electric power generation.62­64 The combustion by methane would somewhat reduce the carbon dioxide emission and the greenhouse effect. Even though methane system. © 2000 American Institute of Physics. S0021-9606 00 00902-8 I. INTRODUCTION Polycyclic aromatic

Sattler, Klaus

357

[Retrieval of monocyclic aromatic hydrocarbons with differential optical absorption spectroscopy].  

PubMed

Differential optical absorption spectroscopy (DOAS) technique has been used to measure trace gases in the atmosphere by their strongly structured absorption of radiation in the UV and visible spectral range, e. g. SO2, NO2, O3 etc. However, unlike the absorption spectra of SO2 and NO2, the analysis of aromatic compounds is difficult and strongly suffers from the cross interference of other absorbers (Herzberg bands of oxygen, ozone and sulfur dioxide), especially with relatively low concentrations of aromatic compounds in the atmosphere. In the present paper, the DOAS evaluation of aromatic compounds was performed by nonlinear least square fit with two interpolated oxygen optical density spectra at different path lengths and reference spectra of ozone at different temperature and SO2 cross section to correct the interference from absorbers of O2, O3 and SO2. The measurement of toluene, benzene, (m, p, o) xylene and phenol with a DOAS system showed that DOAS method is suitable for monocyclic aromatic compounds monitoring in the atmosphere. PMID:17112022

Xie, Pin-Hua; Fu, Qiang; Liu, Jian-Guo; Liu, Wen-Qing; Qin, Min; Li, Ang; Liu, Shi-Sheng; Wei, Qing-Nong

2006-09-01

358

Stimulated anoxic biodegradation of aromatic hydrocarbons using Fe(III) ligands  

USGS Publications Warehouse

Contamination of ground waters with water-soluble aromatic hydrocarbons, common components of petroleum pollution, often produces anoxic conditions under which microbial degradation of the aromatics is slow. Oxygen is often added to contaminated ground water to stimulate biodegradation, but this can be technically difficult and expensive. Insoluble Fe(III) oxides, which are generally abundant in shallow aquifers, are alternative potential oxidants, but are difficult for microorganisms to access. Here we report that adding organic ligands that bind to Fe(III) dramatically increases its bioavailability, and that in the presence of these ligands, rates of degradation of aromatic hydrocarbons in anoxic aquifer sediments are comparable to those in oxic sediments. We find that even benzene, which is notoriously refractory in the absence of oxygen, can be rapidly degraded. Our results suggest that increasing the bioavailability of Fe(III) by adding suitable ligands provides a potential alternative to oxygen addition for the bioremediation of petroleum-contaminated aquifers.Contamination of ground waters with water-soluble aromatic hydrocarbons, common components of petroleum pollution, often produces anoxic conditions under which microbial degradation of the aromatics is slow. Oxygen is often added to contaminated ground water to stimulate biodegradation, but this can be technically difficult and expensive. Insoluble Fe(III) oxides, which are generally abundant in shallow aquifers, are alternative potential oxidants, but are difficult for microorganisms to access. Here we report that adding organic ligands that bind to Fe(III) dramatically increases its bioavailability, and that in the presence of these ligands, rates of degradation of aromatic hydrocarbons in anoxic aquifer sediments are comparable to those in oxic sediments. We find that even benzene, which is notoriously refractory in the absence of oxygen, can be rapidly degraded. Our results suggest that increasing the bioavailability of Fe(III) by adding suitable ligands provides a potential alternative to oxygen addition for the bioremediation of petroleum-contamined aquifers.

Lovley, D.R.; Woodward, J.C.; Chapelle, F.H.

1994-01-01

359

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...

360

Degradation of Aromatic Hydrocarbons by Sphingomonas paucimobilis Strain EPA505  

Microsoft Academic Search

To determine the substrate range capability of Sphingomonas paucimobilis strain EPA505, a number of aromatic compounds were tested as potential growth substrates. Strain EPA505 grew on phenanthrene, naphthalene, fluoranthene, toluene, benzoic acid, 2,3- and 3,4-dihydroxybenzoic acids, 1-chloro-2,4-dinitrobenzene, anthracene, 2-hydroxy-3-naphthoic acid and 1-hydroxy- 2-naphthoic acid, salicylic acid, and catechol. Strain EPA505 was unable to grow on coumarine 3-carboxylic acid, naphthalene dicarboxylic

S. P. Story; E. L. Kline; T. A. Hughes; M. B. Riley; S. S. Hayasaka

2004-01-01

361

Microbial metabolism of polycyclic aromatic hydrocarbons: isolation and characterization of a pyrene-degrading bacterium.  

PubMed Central

Microbiological analyses of sediments located near a point source for petrogenic chemicals resulted in the isolation of a pyrene-mineralizing bacterium. This isolate was identified as a Mycobacterium sp. on the basis of its cellular and colony morphology, gram-positive and strong acid-fast reactions, diagnostic biochemical tests, 66.6% G + C content of the DNA, and high-molecular-weight mycolic acids (C58 to C64). The mycobacterium mineralized pyrene when grown in a mineral salts medium supplemented with nutrients but was unable to utilize pyrene as a sole source of carbon and energy. The mycobacterium grew well at 24 and 30 degrees C and minimally at 35 degrees C. No growth was observed at 5 or 42 degrees C. The mycobacterium grew well at salt concentrations up to 4%. Pyrene-induced Mycobacterium cultures mineralized 5% of the pyrene after 6 h and reached a maximum of 48% mineralization within 72 h. Treatment of induced and noninduced cultures with chloramphenicol showed that pyrene-degrading enzymes were inducible in this Mycobacterium sp. This bacterium could also mineralize other polycyclic aromatic hydrocarbons and alkyl- and nitro-substituted polycyclic aromatic hydrocarbons including naphthalene, phenanthrene, fluoranthene, 3-methylcholanthrene, 1-nitropyrene, and 6-nitrochrysene. This is the first report of a bacterium able to extensively mineralize pyrene and other polycyclic aromatic hydrocarbons containing four aromatic rings. Images PMID:3202633

Heitkamp, M A; Franklin, W; Cerniglia, C E

1988-01-01

362

Production of aromatic hydrocarbons by catalytic pyrolysis of microalgae with zeolites: catalyst screening in a pyroprobe.  

PubMed

Catalytic pyrolysis of microalgae and egg whites was investigated to evaluate the performance of different zeolites for the production of aromatic hydrocarbons. Three zeolites with different structures (H-Y, H-Beta and H-ZSM5) were used to study the effect of catalyst type on the aromatic yield. All three catalysts significantly increased the aromatic yields from pyrolysis of microalgae and egg whites compared with non-catalytic runs, and H-ZSM5 was most effective with a yield of 18.13%. Three H-ZSM5 with silica-to-alumina ratios of 30, 80 and 280 were used to study the effect of Si/Al ratio on the aromatic yield. The maximum yield was achieved at the Si/Al ratio of 80, which provides moderate acidity to achieve high aromatic production and reduce coke formation simultaneously. Aromatic production increased with the incorporation of copper or gallium to HZSM-5. However, other studied metals either had no significant influence or led to a lower aromatic yield. PMID:23642438

Du, Zhenyi; Ma, Xiaochen; Li, Yun; Chen, Paul; Liu, Yuhuan; Lin, Xiangyang; Lei, Hanwu; Ruan, Roger

2013-07-01

363

Determination of aromatic hydrocarbons in gasolines by flow modulated comprehensive two-dimensional gas chromatography.  

PubMed

Valve based/flow modulated comprehensive two-dimensional gas chromatography-flame ionization detection (GC x GC-FID) was used for quantification of C6 through C12 aromatic hydrocarbons by carbon number in gasolines. A 0.53 mm i.d. non-polar first dimension column was coupled to a 0.53 mm i.d. polar second dimension column through a double loop eight port valve modulator. Depending on the sample type, normalized percent and internal standard (I.S.) quantification was performed. For normalized percent quantification, a one-point calibration performed with one aromatic compound per carbon number/class provided an average % accuracy of 2.1% and a short-term n--1 relative standard deviation of 1.0%. For total aromatic compounds good agreement with the more complex conventional multidimensional GC technique was obtained. However, GC x GC has certain advantages over most other methods, mainly increased selectivity for total and carbon number aromatic content. The identification of the aromatic hydrocarbons was confirmed by GC x GC-MS. PMID:16008054

Diehl, John W; Di Sanzo, Frank P

2005-07-01

364

Public health impacts of secondary particulate formation from aromatic hydrocarbons in gasoline  

PubMed Central

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 with exposures to the subset of PM2.5 that originates from vehicle emissions of aromatics under business as usual conditions. Methods The PM2.5 contribution from gasoline aromatics is estimated using the Community Multiscale Air Quality (CMAQ) modeling system and the results are compared to ambient measurements from the literature. Marginal PM2.5 annualized concentration changes are used to calculate premature mortalities using concentration-response functions, with a value of mortality reduction approach used to monetize the social cost of mortality impacts. Morbidity impacts are qualitatively discussed. Results Modeled aromatic SOA concentrations from CMAQ fall short of ambient measurements by approximately a factor of two nationwide, with strong regional differences. After accounting for this model bias, the estimated public health impacts from exposure to PM2.5 originating from aromatic hydrocarbons in gasoline lead to a central estimate of approximately 3800 predicted premature mortalities nationwide, with estimates ranging from 1800 to over 4700 depending on the specific concentration-response function used. These impacts are associated with total social costs of $28.2B, and range from $13.6B to $34.9B in 2006$. Conclusions These preliminary quantitative estimates indicate particulates from vehicular emissions of aromatic hydrocarbons demonstrate a nontrivial public health burden. The results provide a baseline from which to evaluate potential public health impacts of changes in gasoline composition. PMID:23425393

2013-01-01

365

A comparison of the biodegradation of aromatic hydrocarbons in three different systems  

SciTech Connect

In three case studies, the circumstances in which petroleum hydrocarbon biodegradation took place were markedly different. (1) Two reservoir-biodegraded oils from the Barrow Sub-basin. (2) Petroleum hydrocarbons from a condensate which had seeped into a mangrove creek bed. (3) Hydrocarbons in sediments exposed to drilling discharges from an off-shore petroleum platform. For each case, the progress of biodegradation of the aromatic hydrocarbons was studied in detail using GC-MS and GC-FTIR, so that the susceptibility to biodegradation of individual methylated naphthalenes and alkylphenanthrenes could be established. Striking similarities were observed in the progress of biodegradation in the three different environments, especially with the alkylnaphthalenes. One particularly prominent feature of all three systems was that 1,6 dimethyl substituted naphthalenes are more susceptible than other isomers. These similarities raise interesting questions about the mechanisms of biodegradation in these three systems.

Kagi, R.I.; Fisher, S.J.; Alexander, R. [Curtin Univ. of Technology, Perth (Australia)

1996-10-01

366

Atmospheric chemistry of gas-phase polycyclic aromatic hydrocarbons: formation of atmospheric mutagens.  

PubMed Central

The atmospheric chemistry of the 2- to 4-ring polycyclic aromatic hydrocarbons (PAH), which exist mainly in the gas phase in the atmosphere, is discussed. The dominant loss process for the gas-phase PAH is by reaction with the hydroxyl radical, resulting in calculated lifetimes in the atmosphere of generally less than one day. The hydroxyl (OH) radical-initiated reactions and nitrate (NO3) radical-initiated reactions often lead to the formation of mutagenic nitro-PAH and other nitropolycyclic aromatic compounds, including nitrodibenzopyranones. These atmospheric reactions have a significant effect on ambient mutagenic activity, indicating that health risk assessments of combustion emissions should include atmospheric transformation products. PMID:7821285

Atkinson, R; Arey, J

1994-01-01

367

Polycyclic Aromatic Hydrocarbon Degradation of Phytoplankton-Associated Arenibacter spp. and Description of Arenibacter algicola sp. nov., an Aromatic Hydrocarbon-Degrading Bacterium  

PubMed Central

Pyrosequencing of the bacterial community associated with a cosmopolitan marine diatom during enrichment with crude oil revealed several Arenibacter phylotypes, of which one (OTU-202) had become significantly enriched by the oil. Since members of the genus Arenibacter have not been previously shown to degrade hydrocarbons, we attempted to isolate a representative strain of this genus in order to directly investigate its hydrocarbon-degrading potential. Based on 16S rRNA sequencing, one isolate (designated strain TG409T) exhibited >99% sequence identity to three type strains of this genus. On the basis of phenotypic and genotypic characteristics, strain TG409T represents a novel species in the genus Arenibacter, for which the name Arenibacter algicola sp. nov. is proposed. We reveal for the first time that polycyclic aromatic hydrocarbon (PAH) degradation is a shared phenotype among members of this genus, indicating that it could be used as a taxonomic marker for this genus. Kinetic data for PAH mineralization rates showed that naphthalene was preferred to phenanthrene, and its mineralization was significantly enhanced in the presence of glass wool (a surrogate for diatom cell surfaces). During enrichment on hydrocarbons, strain TG409T emulsified n-tetradecane and crude oil, and cells were found to be preferentially attached to oil droplets, indicating an ability by the strain to express cell surface amphiphilic substances (biosurfactants or bioemulsifiers) as a possible strategy to increase the bioavailability of hydrocarbons. This work adds to our growing knowledge on the diversity of bacterial genera in the ocean contributing to the degradation of oil contaminants and of hydrocarbon-degrading bacteria found living in association with marine eukaryotic phytoplankton. PMID:24212584

Rhodes, Glenn; Mishamandani, Sara; Berry, David; Whitman, William B.; Nichols, Peter D.; Semple, Kirk T.; Aitken, Michael D.

2014-01-01

368

Polycyclic aromatic hydrocarbon degradation of phytoplankton-associated Arenibacter spp. and description of Arenibacter algicola sp. nov., an aromatic hydrocarbon-degrading bacterium.  

PubMed

Pyrosequencing of the bacterial community associated with a cosmopolitan marine diatom during enrichment with crude oil revealed several Arenibacter phylotypes, of which one (OTU-202) had become significantly enriched by the oil. Since members of the genus Arenibacter have not been previously shown to degrade hydrocarbons, we attempted to isolate a representative strain of this genus in order to directly investigate its hydrocarbon-degrading potential. Based on 16S rRNA sequencing, one isolate (designated strain TG409(T)) exhibited >99% sequence identity to three type strains of this genus. On the basis of phenotypic and genotypic characteristics, strain TG409(T) represents a novel species in the genus Arenibacter, for which the name Arenibacter algicola sp. nov. is proposed. We reveal for the first time that polycyclic aromatic hydrocarbon (PAH) degradation is a shared phenotype among members of this genus, indicating that it could be used as a taxonomic marker for this genus. Kinetic data for PAH mineralization rates showed that naphthalene was preferred to phenanthrene, and its mineralization was significantly enhanced in the presence of glass wool (a surrogate for diatom cell surfaces). During enrichment on hydrocarbons, strain TG409(T) emulsified n-tetradecane and crude oil, and cells were found to be preferentially attached to oil droplets, indicating an ability by the strain to express cell surface amphiphilic substances (biosurfactants or bioemulsifiers) as a possible strategy to increase the bioavailability of hydrocarbons. This work adds to our growing knowledge on the diversity of bacterial genera in the ocean contributing to the degradation of oil contaminants and of hydrocarbon-degrading bacteria found living in association with marine eukaryotic phytoplankton. PMID:24212584

Gutierrez, Tony; Rhodes, Glenn; Mishamandani, Sara; Berry, David; Whitman, William B; Nichols, Peter D; Semple, Kirk T; Aitken, Michael D

2014-01-01

369

Biogeochemistry of aromatic and saturated hydrocarbons in a rocky intertidal marine community in the Strait of Juan de Fuca  

SciTech Connect

Seasonal distributions of aromatic and saturated hydrocarbons were determined in important members of a rocky intertidal marine community remote from known sources of petroleum input. Nine major species were sampled quarterly for four years at Freshwater Bay, west of Port Angeles on the Strait of Juan de Fuca. More than seventy physical and chemical parameters were obtained for use in evaluating seasonal, annual, and interspecies trends. A simplified food chain study using /sup 3/H-naphthalane added to a seawater-phytoplankton-herbivore-carnivore system demonstrated the transfer of an aromatic petroleum-type hydrocarbon from seawater to organisms typically found in a stable rocky intertidal community. The phytoplankton and herbivore showed a biomagnification of /sup 3/H-naphthalene in the food chain, but the carnivore did not, possibly due to metabolism of the labelled aromatic hydrocarbon and subsequent discharge of water-soluble radioactive products. These studies suggest that aromatic hydrocarbons may be good indicators of short-term petroleum contamination only in species without enzymatic detoxification pathways. Saturated hydrocarbons tend to be better longer-term indicators. Saturated hydrocarbons do not show statistically significant seasonal variations. While organisms displayed some seasonal variations in aromatic hydrocarbons, no universally consistent relationship between seasonal patterns in different organisms was observed. When exposed to spilled oil, organisms similar to Freshwater Bay populations took up different amounts of petroleum hydrocarbons according to type of oil, spill location, duration, and intensity of exposure.

Clark, R.C. Jr.

1983-01-01

370

Detection of aromatic hydrocarbons in the atmosphere at ppt levels  

NASA Astrophysics Data System (ADS)

A new method has been described and evaluated which will detect ppt levels of hydrocarbons in the atmosphere. An automatic GC was used with a concentrator and a photoionization detector to measure benzene, toluene and xylene. The values obtained in the Boston, MA area were in good agreement with the literature value. The BTX data were compared with simultaneous CO 2 data and some interesting features were observed. Good correlation was obtained with simultaneous CO 2 data during rush hour traffic and no correlation during the early morning hours when the BTX values would rise while the CO 2 values decreased to their ambient levels of 350 ppm.

Whalen, M.; Driscoll, J. N.; Wood, C. D.

371

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...

372

IMPORTANCE OF BLACK CARBON IN DISTRIBUTION AND BIOACCUMULATION MODELS OF POLYCYCLIC AROMATIC HYDROCARBONS IN CONTAMINATED MARINE SEDIMENTS  

EPA Science Inventory

The roles and relative importance of nonpyrogenic organic carbon (NPOC) and black carbon (BC) as binding phases of polycyclic aromatic hydrocarbons (PAHs) were assessed by their ability to estimate pore water concentrations and biological uptake in various marine sediments. Sedim...

373

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...

374

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...

375

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...

376

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

2000-01-01

377

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...

378

SYNTHESIS AND BIOLOGICAL ACTIVITY OF CYCLOPENTA EPOXIDES OF PAH (POLYCYCLIC AROMATIC HYDROCARBONS) CONTAINING PERIPHERALLY FUSED CYCLOPENTA RINGS  

EPA Science Inventory

Polycyclic aromatic hydrocarbons (PAH) containing peripherally fused cyclopenta rings have been identified in soots from many different combustion sources. Metabolism and mutagenicity studies have been reported on the series of four cyclopenta-fused isomers derived from benzanthr...

379

The optical spectrum of a large isolated polycyclic aromatic hydrocarbon: hexa-peri-hexabenzocoronene, C42H18  

E-print Network

The first optical spectrum of an isolated polycyclic aromatic hydrocarbon large enough to survive the photophysical conditions of the interstellar medium is reported. Vibronic bands of the first electronic transition of the all benzenoid polycyclic aromatic hydrocarbon hexa-peri-hexabenzocoronene were observed in the 4080-4530 Angstrom range by resonant 2-color 2-photon ionization spectroscopy. The strongest feature at 4264 Angstrom is estimated to have an oscillator strength of f=1.4x10^-3, placing an upper limit on the interstellar abundance of this polycyclic aromatic hydrocarbon at 4x10^12 cm^-2, accounting for a maximum of ~0.02% of interstellar carbon. This study opens up the possibility to rigorously test neutral polycyclic aromatic hydrocarbons as carriers of the diffuse interstellar bands in the near future.

Damian L. Kokkin; Tyler P. Troy; Masakazu Nakajima; Klaas Nauta; Thomas D. Varberg; Gregory F. Metha; Nigel T. Lucas; Timothy W. Schmidt

2008-06-12

380

COMPARISON OF IMMUNOASSAY AND GAS CHROMATOGRAPHY/MASS SPECTROMETRY FOR MEASUREMENT OF POLYCYCLIC AROMATIC HYDROCARBONS IN CONTAMINATED SOIL  

EPA Science Inventory

Polycyclic aromatic hydrocarbons (PAHs) are frequently encountered in the environment and may pose health concerns due to their carcinogenicity. A commercial enzyme-linked immunosorbent assay (ELISA), was evaluated as a screening method for monitoring PAHs at contaminated site...

381

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...

382

Monitoring of polycyclic aromatic hydrocarbons in seafoods from Lake Timsah.  

PubMed

Concentrations of polycyclic aromatic hydrpcarvons (PAHs) in some seafoods caught from Lake Timsah were determined. The tested samples were tilapia fish (Oreochromis aureus), crabs (Portuns pelagicus), bivalves (Venerupis decussata), clams (Strombus tricornis) and gastropods (Munes Sp.). Where these seafoods are locally and favorite consumed foods in the area around the lake (Ismailia governorate). Results showed that crabs contained significantly higher concentrations of both total and carcinogenic PAHs ranging from 1318.6 to 3767.4 and 1230.3 to 3442.2 microg kg(-1), respectively. Meanwhile, clams contained significantly lower levels with mean value of 28.4 microg kg(-1) for total and 24.4 microg kg(-1) for carcinogenic PAHs. The most frequently detected PAHs in the tested samples were indeno(1,2,3-cd)pyrene followed by benzo(a)pyrene, dibenzo(a,h)anthracene, and benzo(b)fluoranthene which are characterized as carcinogenic compounds. PMID:11970818

Mostafa, Gamal A

2002-03-01

383

Reaction of solid carrier-adsorbed polycyclic aromatic hydrocarbons with gaseous low-concentrated nitrogen dioxide.  

PubMed

The interaction of gaseous NO2 with solid carrier-adsorbed polycyclic aromatic hydrocarbons was studied under laboratory conditions with a specific attention to factors that might possibly influence this reaction, such as type of carrier lighting conditions, NO2 concentration, exposure time, and temperature. At the NO2 concentration of 1.33 ppm there were detected the following nitro derivatives: nitroanthracene, nitropyrene, nitrochrysene, two mononitro derivatives of benzo/a/pyrene, and dinitrobenzo/a/pyrene. The experimental data suggest that the formation of nitroaromates in atmospheric environment is to be expected, provided that there are present, besides polycyclic aromatic hydrocarbons and nitrogen oxides, also suitable types of sorbents, such as silica gel or fly ash. PMID:6249866

Jäger, J; Hanus, V

1980-01-01

384

Mineralization of Polycyclic Aromatic Hydrocarbons by the White Rot Fungus Pleurotus ostreatus  

PubMed Central

The white rot fungus Pleurotus ostreatus was able to mineralize to (sup14)CO(inf2) 7.0% of [(sup14)C]catechol, 3.0% of [(sup14)C]phenanthrene, 0.4% of [(sup14)C]pyrene, and 0.19% of [(sup14)C]benzo[a]pyrene by day 11 of incubation. It also mineralized [(sup14)C]anthracene (0.6%) much more slowly (35 days) and [(sup14)C]fluorene (0.19%) within 15 days. P. ostreatus did not mineralize fluoranthene. The activities of the enzymes considered to be part of the ligninolytic system, laccase and manganese-inhibited peroxidase, were observed during fungal growth in the presence of the various polycyclic aromatic hydrocarbons. Although activity of both enzymes was observed, no distinct correlation to polycyclic aromatic hydrocarbon degradation was found. PMID:16535219

Bezalel, L.; Hadar, Y.; Cerniglia, C. E.

1996-01-01

385

Purification and characterization of mouse single-chain antibody against polycyclic aromatic hydrocarbons.  

PubMed

Polycyclic aromatic hydrocarbons (PAH) such as benzo[a]pyren mainly induce lung cancer in humans. We characterized the mouse single chain antibody against benzo[a]pyren (pSh). pSh was expressed and purified as cellulose binding domain fusion (pSh-CBD). The pSh-CBD bound five different PAH with high affinity. The 18 amino acid linker connected pSh-CBD heavy and light chains provided correct protein folding. The KDs for pSh-CBD and polycyclic aromatic hydrocarbons were similar to KDs for monoclonal antibody, approximately 10(-8). Separately heavy and light chains of pSh-CBD did not interact with benzo[a]pyren. Previously defined eleven pSh-CBD aa involved to benzo[a]pyren binding were confirmed by mutagenesis. PMID:24547788

Ustinov, Valentin A; Averjanov, Anton V; Glushkov, Andrey N

2014-01-01

386

Renal cancer risk and occupational exposure to polycyclic aromatic hydrocarbons and plastics  

PubMed Central

Objective To investigate whether occupational exposure to polycyclic aromatic hydrocarbons and certain plastic monomers increased renal cell carcinomas (RCC) risk. Methods Unconditional logistic regression was used to calculate RCC risk in relation to exposure. Results No association between RCC risk and having ever been occupationally exposed to any polycyclic aromatic hydrocarbons or plastics was observed. Duration of exposure and average exposure also showed no association with risk. Suggestive positive associations between RCC risk and cumulative exposure to styrene (P-trend = 0.02) and acrylonitrile (P-trend = 0.06) were found. Cumulative exposure to petroleum/gasoline engine emissions was inversely associated with risk (P-trend = 0.02). Conclusions Results indicate a possible association between occupational styrene and acrylonitrile exposure and RCC risk. Additional studies are needed to replicate findings, as this is the first time these associations have been reported and they may be due to chance. PMID:21270648

Karami, Sara; Boffetta, Paolo; Brennan, Paul; Stewart, Patricia A.; Zaridze, David; Matveev, Vsevolod; Janout, Vladimir; Kollarova, Helena; Bencko, Vladimir; Navratilova, Marie; Szeszenia-Dabrowska, Neonila; Mates, Dana; Gromiec, Jan P.; Sobotka, Roman; Chow, Wong-Ho; Rothman, Nathaniel; Moore, Lee E.

2011-01-01

387

Spectroscopy studies on the selected nitropolycyclic aromatic hydrocarbons compounds in the terahertz region  

NASA Astrophysics Data System (ADS)

In this work, vibrational properties of a series of parent polycyclic aromatic hydrocarbons (PAHs) and nitropolycyclic aromatic hydrocarbons (NPAHs) compounds with the substituted nitro group at different positions have been investigated using terahertz time-domain spectroscopy (THz-TDS) at room temperature. The experimental results show large difference among absorption spectra of several NPAHs and their corresponding parent PAHs compounds in 0.1~2.2 THz region, which probably originated from the difference of NPAHs' molecular structure and lattice vibrational modes. All the experimental NPAHs vibrational modes showed distinct fingerprint absorption in THz region. The study indicates that THz-TDS technology can not only give a new experimental method to identify and analyse such different kinds of NPAHs environmental pollutants, but also provide a useful suggestion for further assessing the possible relationships between the NPAHs optical properties and the effects of the substituted nitro group position to better know their photoreactivity and biochemical activities.

Du, Yong; Liu, Jianjun; Hao, Guohui; Guo, Changsheng; Hong, Zhi

2011-08-01

388

Secondary Aerosol Formation from Oxidation of Aromatics Hydrocarbons by Cl atoms  

NASA Astrophysics Data System (ADS)

Aerosol Formation From the Oxidation of Aromatic Hydrocarbons by Chlorine Atmospheric secondary organic aerosol (SOA) affects regional and global air quality. The formation mechanisms of SOA via the oxidation of volatile organic compounds by hydroxyl radicals, ozone, and nitrate radicals have been studied intensively during the last decade. Chlorine atoms (Cl) also have been hypothesized to be effective oxidants in marine and industrially influenced areas. Recent work by the authors has indicated that significant amounts of SOA are formed from the oxidation of monoterpenes by Cl. Aromatic hydrocarbons are important for generation of both SOA and ozone in urban areas because of their large emission rates and high reactivity. The goal of this work was to quantify the SOA formation potentials of two representative aromatic hydrocarbons through laboratory chamber experiments in which oxidation was initiated by Cl. The system constructed for this study includes an experimental chamber, a gas chromatograph for quantification of aromatic mixing ratios, a Scanning Mobility Particle Spectrometer to measure SOA size distributions, a zero air generator, and an illuminating system. The model aromatic hydrocarbons chosen for this study are toluene and m-xylene. Aerosol yields are estimated based on measured aerosol volume concentration, the concentration of consumed hydrocarbon, and estimation of wall loss of the newly formed aerosol. Toluene and m-xylene exhibit similar SOA yields from the oxidation initiated by Cl. The toluene SOA yield from Cl-initiated oxidation, however, depends on the ratio between the mixing ratios of the initial chlorine source and toluene in the chamber. For toluene experiments with higher such ratios, SOA yields vary from 0.05 to 0.079 for generated aerosol ranging from 4.2 to12.0 micrograms per cubic meter. In the lower ratio experiments, SOA yields are from 0.033 to 0.064, corresponding to generated aerosol from 3.0 to 11.0 micrograms per cubic meter. The m-xylene SOA yield ranges from 0.04 to 0.08 for aerosol in the range of 4.0 to 12.0 micrograms per cubic meter. These yields are generally comparable to those from photooxidation. In marine and industrial areas, SOA formation from the Cl- initiated oxidation of the studied common aromatics is likely to be most important in the early morning.

Cai, X.; Griffin, R.

2006-12-01

389

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

390

Margarines, butter and vegetable oils as sources of polycyclic aromatic hydrocarbons  

Microsoft Academic Search

Concentrations of polycyclic aromatic hydrocarbons (PAH) were determined in Finnish butter, margarines and vegetable oils\\u000a and their raw materials. In all the samples some degree of PAH contamination was found. The average per capita intake was\\u000a estimated at 0.6 g per day. The plant raw materials are supposed to be contaminated by combustion-derived atmospheric particles\\u000a during the growing period. Inappropriate

Anu Hopia; Heikki Pyysalo; Kim Wickström

1986-01-01

391

Factors affecting the polycyclic aromatic hydrocarbon content of cereals, fats and other food products  

Microsoft Academic Search

Factors affecting polycyclic aromatic hydrocarbon (PAH) concentrations in oils and fats, cereals and related foodstuffs have been investigated. Levels of PAHs were low in retail fish and animal?derived oils and fats, such as butter, where the mean benzo(a)pyrene concentration was 0.06 ?g\\/kg. Higher and more variable amounts were present in retail vegetable oils for which the mean level of benzo(a)pyrene

M. J. Dennis; R. C. Massey; G. Cripps; I. Venn; N. Howarth; G. Lee

1991-01-01

392

Effects of ambient temperature on aspects of airborne polycyclic aromatic hydrocarbons  

Microsoft Academic Search

Three- to six-ring polycyclic aromatic hydrocarbons in the vapor phase (PAHs\\/sub vap\\/) and in the particulate phase (PAHs\\/sub pat) and total suspended particulate (TSP) in ambient air were sampled and determined year-round. At ambient temperature levels, substantial amounts of three-to five-ring PAHs were found in the vapor phase depending upon temperature (T, K) and the six-ring PAHs were all found

Hiroyasu Yamasaki; Kazuhiro Kuwata; Hiroko Miyamoto

1982-01-01

393

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

394

Measurement of octanol-air partition coefficients for polycyclic aromatic hydrocarbons and polychlorinated naphthalenes  

Microsoft Academic Search

Measurements of the octanol-air partition coefficient, K{sub OA}, are reported for 4 polycyclic aromatic hydrocarbons (PAHs) and 24 polychlorinated naphthalenes (PCNs) as a function of temperature over the range (0 to 50) C. Results for PAHs are within a factor of 1.5 to 2 of values calculated as the ratio of the octanol-water and air-water partition coefficients. The enthalpies of

Tom Harner; Terry F. Bidleman

1998-01-01

395

Measurement by room-temperature phosphorescence of polynuclear aromatics containing hydrocarbon fuels that permeate glove materials  

Microsoft Academic Search

Permeations of commonly used glove materials by polynuclear aromatic (PNA) compounds in hydrocarbon fuels were measured with solid-state dosemeters composed of filter paper. The permeated PNA were sorbed by the filter paper and analyzed in situ using room-temperature phosphorescence spectroscopy. This technique provided a simple, cost-effective, and very sensitive means for measuring breakthrough times and permeation rates of the class

R. B. Gammage; D. A. White; T. Vo-Dinh

1986-01-01

396

Particle-associated polycyclic aromatic hydrocarbons in urban air of Hong Kong  

Microsoft Academic Search

PM2.5 and PM10 samples were collected at two sampling sites in Hong Kong in wintertime from November 2000 to March 2001 and in summertime from June to August 2001. The concentrations of 16 selected polycyclic aromatic hydrocarbons (PAHs) in aerosols were quantified. Spatial and seasonal variations of PAHs were characterized. The dominated PAHs in PM2.5 and PM10 included benzo[b]fluoranthene, pyrene,

H. Guo; S. c. Lee; K. f. Ho; X. m. Wang; S. c. Zou

2003-01-01

397

Polycyclic aromatic hydrocarbons in sediments and mussels of the western Mediterranean Sea  

Microsoft Academic Search

The distribution of polycyclic aromatic hydrocarbons (PAHs) has been investigated in superficial sediments and mussels (Mytilus galloprovincialis) of the western Mediterranean sea. The analyses were performed by gas chromatography coupled to mass spectrometry (GC-MS). The PAH concentrations ranged from 1 to 20,500 ng\\/g in the sediments. Different molecular indices allowed differentiation between the different pollutant sources. On the French coast,

Pascale Baumard; Hélène Budzinski; Philippe Garrigues

1998-01-01

398

Biodegradation kinetics of select polycyclic aromatic hydrocarbon (PAH) mixtures by Sphingomonas paucimobilis EPA505  

Microsoft Academic Search

Many contaminated sites commonly have complex mixtures of polycyclic aromatic hydrocarbons (PAHs) whose individual microbial\\u000a biodegradation may be altered in mixtures. Biodegradation kinetics for fluorene, naphthalene, 1,5-dimethylnaphthalene and\\u000a 1-methylfluorene were evaluated in sole substrate, binary and ternary systems using Sphingomonas paucimobilis EPA505. The first order rate constants for fluorene, naphthalene, 1,5-dimethylnaphthalene, and 1-methylfluorene were comparable;\\u000a yet Monod parameters were significantly

Anuradha M. Desai; Robin L. Autenrieth; Petros Dimitriou-Christidis; Thomas J. McDonald

2008-01-01

399

Urinary 1-hydroxypyrene levels of garbage collectors with low-level exposure to polycyclic aromatic hydrocarbons  

Microsoft Academic Search

Because garbage collectors work in the street, they are exposed to polycyclic aromatic hydrocarbons (PAHs) in motor vehicle exhaust gas as they work. Urinary 1-hydroxypyrene (1-OH-pyrene) began to be used as a biological monitoring index for human exposure to high concentrations of PAHs. The objective of this study was to examine the applicability of urinary 1-OH-pyrene as a biological monitoring

Kunio Hara; Tomoyuki Hanaoka; Yuko Yamano; Toru Itani

1997-01-01

400

Problems in the Extraction of Polycyclic Aromatic Hydrocarbons from Diesel Particulate Matter  

Microsoft Academic Search

In this work, a comparison between Soxhlet, ultrasonic, and microwave-assisted extraction (MAE) (using hexane:acetone 1:1) of polycyclic aromatic hydrocarbons (PAHs) from SRM 1650 diesel particulate matter was made. As good recoveries were not obtained for the higher molecular weight compounds, MAE with toluene and dichloromethane was also tested. Achieved recoveries were compared with the results obtained in the same assays

M. Piñeiro-Iglesias; P. López-Mahía; E. Vázquez-Blanco; S. Muniategui-Lorenzo; D. Prada-Rodríguez

2002-01-01

401

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

402

Sources of Polycyclic Aromatic Hydrocarbons in Louisiana Rivers and Coastal Environments: Principal Components Analysis  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs) sources in Louisiana Rivers and coastal environments were characterized using principal components analysis (PCA). Distinctive clustering revealed petrogenic, pyrogenic, and biogenic\\/diagenetic origins of the PAHs. PCA included data from analysis of 478 samples selected from a pool of 3,540 samples for which the sum of 34 alkylated and non-alkylated PAHs and petroleum biomarker compounds, determined by

Javed Iqbal; Edward B. Overton; David Gisclair

2008-01-01

403

Enhanced sorption of polycyclic aromatic hydrocarbons by soil amended with biochar  

Microsoft Academic Search

Purpose  Polycyclic aromatic hydrocarbon (PAHs) are ubiquitous pollutants in agricultural soils in China. Biochar is the charred product\\u000a of biomass pyrolysis, which is widely applied to soils to sequestrate atmospheric carbon dioxide and guarantees a long-term\\u000a benefit for soil fertility. Knowledge about the impacts of various biochars on soil sorption affinity remains obscure. In\\u000a this study, we evaluated the effects of

Baoliang Chen; Miaoxin Yuan

2011-01-01

404

Oxidation of Polycyclic Aromatic Hydrocarbons (PAH) by Laccase of Trametes Versicolor  

Microsoft Academic Search

Laccase of Trametes versicolor was able to oxidize in vitro most of the 14 polycyclic aromatic hydrocarbons (PAH) tested. Acenaphthylene was removed by 37% followed by anthracene and benzo[a]pyrene which were oxidized by 18 and 19%, respectively. Lower but significant oxidation of about 10% was found for eight additional PAH: acenaphthene, fluoranthene, pyrene, benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, and perylene. Naphthalene,

Andrzej Majcherczyk; Christian Johannes; Aloys Hüttermann

1998-01-01

405

Polycyclic aromatic hydrocarbons in Recent lake sediments--I. Compounds having anthropogenic origins  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAH) in sediment cores from Lake Lucerne, Lake Zürich, and Greifensee, Switzerland, and Lake Washington, northwest U.S.A., have been isolated, identified and quantified by glass capillary gas chromatography and gas chromatography\\/mass spectrometry. Surface sediment layers are greatly enriched in PAH--up to 40 times--compared to deeper layers. In addition, concentration increases in upper sediments generally correspond to increasing

Stuart G. Wakeham; Christian Schaffner; Walter Giger

1980-01-01

406

Distribution and sources of polycyclic aromatic hydrocarbons in sediments from Kyeonggi Bay, Korea  

Microsoft Academic Search

Sixty-six sediment samples were collected from Kyeonggi Bay, Korea, in December 1995 and analysed for a suite of 2–6 ring polycyclic aromatic hydrocarbons (PAHs). Sediments were collected in the Han River estuary, Incheon Harbour, from nearshore locations adjacent to large industrial complexes south of Incheon, and along transects toward the open sea. Concentrations of PAHs (9.1–1400 ng g?1 dry wt

Gi Beum Kim; Keith A. Maruya; Richard F. Lee; Jong-Hyeon Lee; Chul-Hwan Koh; Shinsuke Tanabe

1999-01-01

407

Polycyclic Aromatic Hydrocarbons (PAH) in Water and Sediment from Gully Pots  

Microsoft Academic Search

A gully pot is often cleaned with the help of an eductor truck, which uses hydrodynamic pressure and a vacuum to loosen and\\u000a remove the solids and standing liquid from a gully pot. This paper considers the polycyclic aromatic hydrocarbons (PAH) content\\u000a in the gully pot mixture (water and sediment) after it has been discharged from the eductor truck. The

Kristin Karlsson; Maria Viklander

2008-01-01

408

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

409

Phytoremediation of Alkylated Polycyclic Aromatic Hydrocarbons in a Crude Oil-Contaminated Soil  

Microsoft Academic Search

Phytoremediation uses plants and their associated microorganisms in conjunction with agronomic techniques to remove or degrade\\u000a environmental contaminants. The objective of the field study was to evaluate the effect of vegetation establishment plus fertilizer\\u000a addition on the biodegradation of alkylated polycyclic aromatic hydrocarbons in a crude oil-contaminated soil. Four replications\\u000a of the following treatments were used: non-vegetated non-fertilized control; fescue

Paul M. White; Duane C. Wolf; Gregory J. Thoma; Charles M. Reynolds

2006-01-01

410

Effect of Salinity on Biodegradation of Polycyclic Aromatic Hydrocarbons (PAHs) of Heavy Crude Oil in Soil  

Microsoft Academic Search

The spillage of crude oil in the soil damages the environment. Polycyclic aromatic hydrocarbons (PAHs) are one of the crude\\u000a oil components that may be harmful for living organisms. PAHs can disappear from the environment by volatilization and biodegradation.\\u000a The effect of different NaCl concentrations (0%–5%) on PAHs reduction from the heavy crude oil-contaminated soil was studied.\\u000a Our results showed

Dariush Minai-Tehrani; Saeed Minoui; Ali Herfatmanesh

2009-01-01

411

Quantification and Source Identification of Polycyclic Aromatic Hydrocarbons in Core Sediments from Sundarban Mangrove Wetland, India  

Microsoft Academic Search

The distribution and potential sources of 16 polycyclic aromatic hydrocarbons (PAHs) in sediment cores (<63 ?m particle size)\\u000a of the Sundarban mangrove wetland, northeastern coast of Bay of Bengal (India), were investigated by gas chromatography coupled\\u000a to mass spectrometry. The total concentrations of 16 PAHs (?16PAHs) ranged from 132 to 2938 ng\\/g, with a mean of 634 ng\\/g, and the sum of

C. Domínguez; S. K. Sarkar; A. Bhattacharya; M. Chatterjee; B. D. Bhattacharya; E. Jover; J. Albaigés; J. M. Bayona; K. K. Satpathy

2010-01-01

412

Distribution of Polycyclic Aromatic Hydrocarbons in Soils of an Arid Urban Ecosystem  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental pollutants produced by incomplete combustion sources\\u000a such as home heating, biomass burning, and vehicle emissions. PAH concentrations in soils are influenced by source inputs\\u000a and environmental factors that control loss processes and soil retention. Many studies have found higher concentrations of\\u000a these pollutants in soils within cities of temperate climates that have a

Yevgeniy Marusenko; Pierre Herckes; Sharon J. Hall

2011-01-01

413

Ionic liquid-containing semipermeable membrane devices for monitoring the polycyclic aromatic hydrocarbons in water  

Microsoft Academic Search

Ionic liquid-containing semipermeable membrane devices (IL-SPMDs) were developed to monitor the polycyclic aromatic hydrocarbons in water. Uptake kinetics of naphthalene, 1-methylnaphthalene, phenanthrene, pyrene, chrysene by layflat low-density polyethylene tubing (15cm×2cm) filled with 0.5ml 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid were studied in a laboratory continuous-flow system for the duration of 16 days. The device concentration factors were in the range of 830–7800

Wenyan Zhao; Meng Han; Shugui Dai; Jian Xu; Ping Wang

2006-01-01

414

Synthesis, Electronic Properties and WOLED Devices of Planar Phosphorus-Containing Polycyclic Aromatic Hydrocarbons.  

PubMed

We describe the synthesis and the physical properties of polyaromatic hydrocarbons (PAHs) containing a phosphorus atom at the edge. In particular, the impact of the successive addition of aromatic rings on the electronic properties was investigated by experimental (UV/Vis absorption, fluorescence, cyclic voltammetry) and theoretical studies (DFT). The physical properties recorded in solution and in the solid state showed that the P-containing PAHs exhibit properties expected for an emitter in white organic light-emitting diodes (WOLEDs). PMID:25760307

Riobé, François; Sz?cs, Rózsa; Bouit, Pierre-Antoine; Tondelier, Denis; Geffroy, Bernard; Aparicio, Fátima; Buendía, Julia; Sánchez, Luis; Réau, Régis; Nyulászi, László; Hissler, Muriel

2015-04-20

415

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

416

PFI-ZEKE SPECTROSCOPY AND THEORETICAL CALCULATIONS OF TRANSITION METAL-AROMATIC HYDROCARBON COMPLEXES  

Microsoft Academic Search

Transition metal-aromatic hydrocarbon complexes were generated in a supersonic jet and studied by zero electron kinetic energy (ZEKE) photoelectron spectroscopy and theoretical calculations. The target metal complexes were identified using time-of-flight mass spectrometry, and their ionization thresholds were located via photoionization efficiency spectroscopy. ZEKE spectroscopy was used to measure the ionization energies and vibrational frequencies of the metal complexes. Their

Bradford Raymond Sohnlein

2007-01-01

417

Occurrence and fate of polycyclic aromatic hydrocarbons in the coastal surface microlayer  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs) were measured in the coastal sea surface microlayer (SML), the sub-surface waters (SSW) and the overlying atmosphere in order to investigate the influence of the SML on contaminant enrichment and air–sea exchange. Samples were collected at two contrasting locations of the NW Mediterranean, one urban influenced (off Barcelona, Spain) and another comparatively clean (off Banyuls-sur-Mer, France).

Carlos Guitart; Nuria García-Flor; Josep M. Bayona; Joan Albaigés

2007-01-01

418

Phototoxicity of non-carcinogenic polycyclic aromatic hydrocarbons in aquatic organisms  

SciTech Connect

Anthracene, fluoranthene, and pyrene are phototoxic in Daphnia magna, Artemia salina, first instar larvae of Aedes aegypti, late embryonic forms of Rana pipiens, and fish (Pimephales promelas). Since polycyclic aromatic hydrocarbons are generated in the combustion processes held responsible for the damages of acid rain, and they are introduced into the environment through other means as well, the high phototoxicity of the major pollutants, which are not carcinogenic, suggests that greater attention must be given to their environmental significance.

Kagan, J.; Kagan, E.D.; Kagan, I.A.; Kagan, P.A.; Quigley, S.

1985-01-01

419

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

420

Matrix-immobilized organoclay for the sorption of polycyclic aromatic hydrocarbons and pentachlorophenol from groundwater  

Microsoft Academic Search

Sorbent materials consisting of organoclay immobilized onto the surface of a solid support were evaluated for use in pentachlorophenol (PCP) and polycyclic aromatic hydrocarbon (PAH) remediation of groundwater at a creosote-contaminated Superfund site. Cetylpyridinium-exchanged low pH montmorillonite clay (CP-LPHM) was bonded to either sand (CP-LPHM\\/sand) or granular activated carbon (GAC) (CP-LPHM\\/GAC) using the free acid form of carboxymethylcellulose as an

Melinda C. Wiles; Henry J. Huebner; Thomas J. McDonald; Kirby C. Donnelly; Timothy D. Phillips

2005-01-01

421

Removal of probable human carcinogenic polycyclic aromatic hydrocarbons from contaminated water using molecularly imprinted polymer  

Microsoft Academic Search

A molecularly imprinted polymer (MIP) adsorbent for carcinogenic polycyclic aromatic hydrocarbons (PAHs) was prepared using a non-covalent templating technique. MIP particles sized from 2 to 5?m were synthesized in acetonitrile by using six PAHs mix as a template, methacrylic acid as the functional monomer, and ethylene glycol dimethacrylate as the cross-linker. When compared with the non-imprinted polymer (NIP), the MIP

Reddithota J. Krupadam; Muntazir S. Khan; Satish R. Wate

2010-01-01

422

Structures and electronic properties of thin-films of polycyclic aromatic hydrocarbons  

Microsoft Academic Search

We report the fabrication and characterization of organic thin-film transistors (TFTs) using several polycyclic aromatic hydrocarbons (PAHs). Pentacene, ovalene, dibenzocoronene and hexabenzocoronene were deposited as organic semiconductors on silicon wafers with gold electrodes as the bottom-contact configuration of the TFTs. The pentacene TFT showed the highest field-effect mobility of more than 0.1 cm2\\/Vs in comparison with the other PAHs. The results

Yutaka Natsume; Takashi Minakata; Takeshi Aoyagi

2009-01-01

423

Transition metal sandwich molecules with large (C n , n ? 24) zigzag poly aromatic hydrocarbons  

Microsoft Academic Search

Ab initio plane wave based density functional theory was used to study the electronic structure and geometry of sandwich structures MnR2 consisting of a layer of palladium metal atoms between large eclipsed pericondensed aromatic hydrocarbon molecules: ovalene C32H14, circumanthracene C40H16, circumpyrene C42H16 and circumcoronene C54H18. The analysis was guided by the results from the smaller sandwiches: Pd(C6H6)2, symmetric isomers of

Michael R. Philpott; Yoshiyuki Kawazoe

2008-01-01

424

Hydrogen transfer reaction in polycyclic aromatic hydrocarbon radicals.  

PubMed

Density functional theory calculations have been successfully applied to investigate the formation of hydrocarbon radicals and hydrogen transfer pathways related to the chemical vapor infiltration process based on model molecules of phenanthrene, anthra[2,1,9,8-opqra]tetracene, dibenzo[a,ghi]perylene, benzo[uv]naphtho[2,1,8,7-defg]pentaphene, and dibenzo[bc,ef]ovalene. The hydrogen transfer reaction rate constants are calculated within the framework of the Rice-Ramsperger-Kassel-Marcus theory and the transition state theory by use of the density functional theory calculation results as input. From these calculations, it is concluded that the hydrogen transfer reaction between two bay sites can happen almost spontaneously with energy barrier as low as about 4.0 kcal mol(-1), and the hydrogen transfer reactions between two armchair sites possess lower energy barrier than those between two zigzag sites. PMID:24893119

Liu, Huiting; Yan, Liuming; Yue, Baohua; Li, Aijun

2014-06-26

425

Optimizing catalysis conditions to decrease aromatic hydrocarbons and increase alkanes for improving jet biofuel quality.  

PubMed

To produce quality jet biofuel with high amount of alkanes and low amount of aromatic hydrocarbons, two zeolites of HY and HZSM-5 supporting Ni and Mo were used as catalysts to convert soybean oil into jet fuel. Zeolite HY exhibited higher jet range alkane selectivity (40.3%) and lower jet range aromatic hydrocarbon selectivity (23.8%) than zeolite HZSM-5 (13.8% and 58.9%). When reaction temperature increased from 330 to 390°C, yield of jet fuel over Ni-Mo/HY catalyst at 4 MPa hydrogen pressure increased from 0% to 49.1% due to the shift of reaction pathway from oligomerization to cracking reaction. Further increase of reaction temperature from 390 to 410°C resulted in increased yield of jet range aromatic hydrocarbons from 18.7% to 30%, which decreased jet fuel quality. A high yield of jet fuel (48.2%) was obtained at 1 MPa low hydrogen pressure over Ni (8 wt.%)-Mo (12 wt.%)/HY catalyst. PMID:24656484

Cheng, Jun; Li, Tao; Huang, Rui; Zhou, Junhu; Cen, Kefa

2014-04-01

426

Formation of polycyclic aromatic hydrocarbons and their growth to soot—a review of chemical reaction pathways  

Microsoft Academic Search

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 discusses a general scheme of PAH formation and sequential growth of PAH by reactions with stable and radical species, including single-ring aromatics, other PAH

H. Richter; J. B. Howard

2000-01-01

427

Spatial and temporal trends of polycyclic aromatic hydrocarbons and other traffic-related airborne pollutants in New York City.  

PubMed

Traffic-related air pollutants have been associated with adverse health effects. We hypothesized that exposure to polycyclic aromatic hydrocarbons (PAHs), elemental carbon (EC, diesel indicator), particulate matter (PM2.5), and a suite of metals declined from 1998 to 2006 in NYC due to policy interventions. PAH levels from personal monitoring of pregnant mothers participating in the Columbia's Center for Children's Environmental Health birth cohort study, and EC, PM2.5, and metal data from five New York State Department of Environmental Conservation stationary monitors were compared across sites and over time (1998-2006). Univariate analysis showed a decrease in personal PAHs exposures from 1998 to 2006 (p < 0.0001). After controlling for environmental tobacco smoke, indoor heat, and cooking, year of personal monitoring remained a predictor of decline in sigmaPAHs (beta = -0.269, p < 0.001). Linear trend analysis also suggested that PM2.5 declined (p = 0.09). Concentrations of EC and most metals measured by stationary site monitors, as measured by ANOVA, did not decline. Across stationary sites, levels of airborne EC and metals varied considerably. By contrast PM2.5 levels were highly intercorrelated (values ranged from 0.725 to 0.922, p < 0.01). Further policy initiatives targeting traffic-related air pollutants may be needed for a greater impact on public health. PMID:18939566

Narváez, Rafael F; Hoepner, Lori; Chillrud, Steven N; Yan, Beizhan; Garfinkel, Robin; Whyatt, Robin; Camann, David; Perera, Frederica P; Kinney, Patrick L; Miller, Rachel L

2008-10-01

428

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

429

Formation of Polycyclic Aromatic Hydrocarbons and Nitrogen Containing Polycyclic Aromatic Compounds in Titan's Atmosphere, the Interstellar Medium and Combustion  

NASA Astrophysics Data System (ADS)

Several different mechanisms leading to the formation of (substituted) naphthalene and azanaphthalenes were examined using theoretical quantum chemical calculations. As a result, a series of novel synthetic routes to Polycyclic Aromatic Hydrocarbons (PAHs) and Nitrogen Containing Polycyclic Aromatic Compounds (N-PACs) have been proposed. On Earth, these aromatic compounds originate from incomplete combustion and are released into our environment, where they are known to be major pollutants, often with carcinogenic properties. In the atmosphere of a Saturn's moon Titan, these PAH and N-PACs are believed to play a critical role in organic haze formation, as well as acting as chemical precursors to biologically relevant molecules. The theoretical calculations were performed by employing the ab initio G3(MP2,CC)/B3LYP/6-311G** method to effectively probe the Potential Energy Surfaces (PES) relevant to the PAH and N-PAC formation. Following the construction of the PES, Rice-Ramsperger-Kassel-Markus (RRKM) theory was used to evaluate all unimolecular rate constants as a function of collision energy under single-collision conditions. Branching ratios were then evaluated by solving phenomenological rate expressions for the various product concentrations. The most viable pathways to PAH and N-PAC formation were found to be those where the initial attack by the ethynyl (C2H) or cyano (CN) radical toward a unsaturated hydrocarbon molecule led to the formation of an intermediate which could not effectively lose a hydrogen atom. It is not until ring cyclization has occurred, that hydrogen elimination leads to a closed shell product. By quenching the possibility of the initial hydrogen atom elimination, one of the most competitive processes preventing the PAH or N-PAC formation was avoided, and the PAH or N-PAC formation was allowed to proceed. It is concluded that these considerations should be taken into account when attempting to explore any other potential routes towards aromatic compounds in cold environments, such as on Titan or in the interstellar medium.

Landera, Alexander

430

Remediation of a chlorinated aromatic hydrocarbon in water by photoelectrocatalysis.  

PubMed

Photoelectrocatalysis driven by visible light offers a new and potentially powerful technology for the remediation of water contaminated by organo-xenobiotics. In this study, the performance of a visible light-driven photoelectrocatalytic (PEC) batch reactor, applying a tungsten trioxide (WO(3)) photoelectrode, to degrade the model pollutant 2,4-dichlorophenol (2,4-DCP) was monitored both by toxicological assessment (biosensing) and chemical analysis. The bacterial biosensor used to assess the presence of toxicity of the parent molecule and its breakdown products was a multicopy plasmid lux-marked E. coli HB101 pUCD607. The bacterial biosensor traced the removal of 2,4-DCP, and in some case, its toxicity response suggests the identification of transient toxic intermediates. The loss of the parent molecule, 2,4-DCP determined by HPLC, corresponded to the recorded photocurrents. Photoelectrocatalysis offers considerable potential for the remediation of chlorinated hydrocarbons, and that the biosensor based toxicity results identified likely compatibility of this technology with conventional, biological wastewater treatment. PMID:18789564

Nissen, Silke; Alexander, Bruce D; Dawood, Ilyas; Tillotson, Martin; Wells, Richard P K; Macphee, Donald E; Killham, Kenneth

2009-01-01

431

Activated carbon and biochar amendments decrease pore-water concentrations of polycyclic aromatic hydrocarbons (PAHs) in sewage sludge  

E-print Network

- tion, which is one way of sewage sludge disposal, is very expensive and meets opposition from hydrocarbons (PAHs) in sewage sludge Patryk Oleszczuk a,b, , Sarah E. Hale a , Johannes Lehmann c , Gerard Polycyclic aromatic hydrocarbons Bioavailability Sewage sludge a b s t r a c t The aim of the research

Lehmann, Johannes

432

Polycyclic aromatic hydrocarbons of coal fly ash: Analysis by gas?liquid chromatography using nematic liquid crystals  

Microsoft Academic Search

The seasonal variations over a period of 12 m in the amounts of polycyclic aromatic hydrocarbons (PAH) in fly?ash samples collected from the electrostatic precipitator of a thermal power plant have been studied. PAH generally did not show much seasonal variation. The gas?liquid chromatographic (GLC) analysis of benezene extract of fly ash showed the presence of 28 polyaromatic hydrocarbons, of

V. K. Srivastava; P. K. Srivastava; U. K. Misra

1985-01-01

433

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

PubMed

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%. PMID:11539437

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

1994-01-01

434

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

435

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

436

Current-density maps as probes of aromaticity: global and Clar pi ring currents in totally resonant polycyclic aromatic hydrocarbons.  

PubMed

Calculation and visualisation of induced current density are important aids to the study of both aromaticity and observable molecular magnetic response properties. The ipsocentric method offers an accurate and economical approach to calculation of induced current density, and a physical interpretation in terms of occupied-orbital contributions. In monocyclic systems, these contributions allow rationalisation of the existence, sense, and strength of ring current using simple symmetry and node-counting arguments. Here we show maps computed with the model pseudo-pi version of the ipsocentric theory for large polycyclic aromatic hydrocarbons (PAH) of the Clar type. Maps are presented for D(6h)-symmetric systems with up to 438 carbon centres; a full ab initio calculation for an isomer of C114H30 confirms that the success of the pseudo-pi method for small PAH carries over to these larger systems. The computed maps follow a generic overall pattern that can be understood with a natural extension of the orbital arguments to a 'band theory' of totally resonant PAH. All show pi current densities that combine a Clar-sextet structure of localised benzenoid diatropic ring currents (contributed by just four HOMO electrons) with a global perimeter diatropic ring current contributed by the remaining pi electrons. Both currents are explained in the ipsocentric model: the localised currents arise from excitations from the HOMO; the perimeter current from excitations from the rest of the HOMO-band. PMID:17328436

Steiner, Erich; Fowler, Patrick W; Soncini, Alessandro; Jenneskens, Leonardus W

2007-01-01

437

Polycyclic Aromatic Hydrocarbons–Aromatic DNA Adducts in Cord Blood and Behavior Scores in New York City Children  

PubMed Central

Background: Airborne polycyclic aromatic hydrocarbons (PAH) are widespread urban pollutants that can bind to DNA to form PAH–DNA adducts. Prenatal PAH exposure measured by personal monitoring has been linked to cognitive deficits in childhood in a prospective study conducted by the Columbia Center for Children’s Environmental Health. Objectives: We measured PAH–DNA and other bulky aromatic adducts in umbilical cord white blood cells using the 32P-postlabeling assay to determine the association between this molecular dosimeter and behavioral/attention problems in childhood. Methods: Children born to nonsmoking African-American and Dominican women residing in New York City (NYC) were followed from in utero to 7–8 years of age. At two time points before 8 years of age (mean ages, 4.8 years and 7 years), child behavior was assessed using the Child Behavior Checklist (CBCL). To estimate and test the association between adducts and behavioral outcomes, both CBCL continuous raw scores and dichotomized T-scores were analyzed. Results: Higher cord adducts were associated with higher symptom scores of Anxious/Depressed at 4.8 years and Attention Problems at 4.8 and 7 years, and with Diagnostic and Statistical Manual of Mental Disorders, 4th edition–oriented Anxiety Problems at 4.8 years. Conclusions: These results suggest that PAH exposure, measured by DNA adducts, may adversely affect child behavior, potentially affecting school performance. PMID:21486719

Wang, Shuang; Vishnevetsky, Julia; Zhang, Bingzhi; Cole, Kathleen J.; Tang, Deliang; Rauh, Virginia; Phillips, David H.

2011-01-01

438

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

439

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

440

Nitro-polycyclic aromatic hydrocarbons and polycyclic aromatic hydrocarbons in particulate matter in an urban area of a tropical region: Ho Chi Minh City, Vietnam  

NASA Astrophysics Data System (ADS)

Urban air pollution in many cities of the developing world in Asia, particularly in Vietnam, is increasing significantly. Atmospheric particulate matter pollution is dangerous to the health of millions of people and is a particular concern. In this study, two nitro-polycyclic aromatic hydrocarbons (nitro-PAHs), 1-nitropyrene (1-NP) and 2-nitrofluoranthene (2-NF) and several polycyclic aromatic hydrocarbons (PAHs)—highly carcinogenic and mutagenic compounds—were quantified in particulate matter (PM) collected at three ambient air sites (VNU, ITTE and DOSTE) in an urban area of Ho Chi Minh City, Vietnam, between January 2005 and March 2006. The DOSTE site was close to ground level on a street with a high traffic density. 2-NF was more abundant than 1-NP at all sampling sites. Concentrations of 1-NP and PAHs at the traffic site (DOSTE) were higher than those at the other sites (VNU and ITTE). The daytime/nighttime distribution of 2-NF and the 2-NF/1-NP ratios were used to evaluate the gas-phase formation of 2-NF and its formation route. The average ratios of 2-NF/1-NP at the VNU and ITTE sites were much higher than those at the DOSTE site, suggesting that the gas-phase reactions are an important source of 2-NF in the ambient air. The higher nighttime concentration of 2-NF observed at the VNU and ITTE sites and the converse result observed for the traffic site indicates that an NO 3 radical-initiated reaction is the dominant route for 2-NF formation in ambient air, while the majority of 2-NF at the traffic site may be attributed to OH radical-initiated reactions.

Hien, To Thi; Thanh, Le Tu; Kameda, Takayuki; Takenaka, Norimichi; Bandow, Hiroshi

441

Polycyclic aromatic hydrocarbons and petroleum biomarkers in São Sebastião Channel, Brazil: assessment of petroleum contamination.  

PubMed

Polycyclic aromatic hydrocarbons (PAHs) and non-aromatic hydrocarbons (NAHs), including n-alkanes, isoprenoids and petroleum biomarkers (terpanes, hopanes, steranes and diasteranes), were quantified by gas chromatography with flame ionization and mass spectrometer detectors in sediment samples collected from the São Sebastião Channel (SSC), Brazil, where the largest Brazilian maritime petroleum terminal is located. The concentrations of total PAHs, total n-alkanes and petroleum biomarkers ranged from below the detection limits to 370ngg(-1), 28microgg(-1), 2200ngg(-1) (dry weight), respectively. The analysis of PAH distribution suggested combustion sources of PAHs as the main input for these compounds with smaller amount from petroleum contamination. The distribution of petroleum biomarkers undoubtedly demonstrated petroleum as a source of anthropogenic contamination throughout the region. The assessment of petrogenic sources of contamination in marine sediment is more challenging if only PAH analysis were carried out, which demonstrates that more stable hydrocarbons such as petroleum biomarkers are useful for investigating potential presence of petroleum. PMID:20005568

da Silva, Denis A M; Bícego, Márcia C

2010-06-01

442

Aromatic hydrocarbon degradation in hydrogen peroxide- and nitrate-amended microcosms  

SciTech Connect

Fifty microcosms were constructed using aquifer materials from a former coal gasification site and divided into four groups: poisoned control, nutrient-free control, hydrogen peroxide-amended, and nitrate-amended microcosms. Each microcosm contained site soil and groundwater in a 1.2-L glass media bottle. When depleted, hydrogen peroxide and sodium nitrate were injected into the microcosms. Microcosms were periodically sacrificed for analysis of polycyclic aromatic hydrocarbons (PAHs); monocyclic aromatic hydrocarbons (benzene, toluene, ethylbenzene, and xylenes [BTEX]); total petroleum hydrocarbons (TPH); and heterotrophic plate counts (HPCs). BTEX and two- and three-ringed PAHs were degraded in microcosms receiving electron-acceptor additions compared to poisoned controls. Four-, five-, and six-ringed PAHs were not significantly degraded during this study. Except in poisoned controls, significant amounts of dissolved oxygen (DO) or nitrate were utilized, and microbial populations increased by 3 to 5 orders of magnitude compared to site soils used to assemble the microcosms (i.e., baseline samples).

Christian, B.J.; Pugh, L.B.; Clarke, B.H. [Earth Technology, Grand Rapids, MI (United States)

1995-12-31

443

Combination processing of pyrolysis naphtha to obtain aromatic hydrocarbons and high-octane gasolines  

SciTech Connect

In the pyrolysis of hydrocarbon feedstocks, production of the desired monomer - ethylene - is accompanied by the formation of pyrolysis naphtha, which has a high content of benzene (30%) and hence is processed solely for benzene recovery. In view of the increased demand for automotive gasolines, this processing scheme is extremely illogical. One of the possible means for rational utilization of pyrolysis naphtha is the combined production of high-octane unleaded gasolines and aromatic hydrocarbons, mainly benzene. With such a scheme, the pyrolysis naphtha and the fractions segregated from the naphtha can be processed separately. Another problem that requires a fast solution is the production of ecologically clean modified gasolines. The production and use of leaded gasolines are being phased out universally, in the interest of improving environmental health. For the improvement of octane number, tetraethyllead is being replaced by oxygen-containing compounds, mainly methyl tert-butyl ether and methyl tert-amyl ether. These oxygenates are used at concentrations of 2.0-2.7% in the gasoline. The content of aromatic hydrocarbons (particularly benzene) is limited to 1%. In this article we will describe an optimal scheme for processing pyrolysis naphtha, yielding benzene and AI-93 high-quality unleaded gasoline.

Guseinova, A.D.; Asker-Zade, S.M.; Mubarak, A.R.M. [and others

1994-07-01

444

Reaction dynamics in astrochemistry: low-temperature pathways to polycyclic aromatic hydrocarbons in the interstellar medium.  

PubMed

Bimolecular reactions of phenyl-type radicals with the C4 and C5 hydrocarbons vinylacetylene and (methyl-substituted) 1,3-butadiene have been found to synthesize polycyclic aromatic hydrocarbons (PAHs) with naphthalene and 1,4-dihydronaphthalene cores in exoergic and entrance barrierless reactions under single-collision conditions. The reaction mechanism involves the initial formation of a van der Waals complex and addition of a phenyl-type radical to the C1 position of a vinyl-type group through a submerged barrier. Investigations suggest that in the hydrocarbon reactant, the vinyl-type group must be in conjugation with a -C?CH or -HC=CH2 group to form a resonantly stabilized free radical intermediate, which eventually isomerizes to a cyclic intermediate followed by hydrogen loss and aromatization (PAH formation). The vinylacetylene-mediated formation of PAHs might be expanded to more complex PAHs, such as anthracene and phenanthrene, in cold molecular clouds via barrierless reactions involving phenyl-type radicals, such as naphthyl, which cannot be accounted for by the classical hydrogen abstraction-acetylene addition mechanism. PMID:25422849

Kaiser, Ralf I; Parker, Dorian S N; Mebel, Alexander M

2015-04-01

445

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

446

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

447

A Theoretical Study on the Vibrational Spectra of Polycyclic Aromatic Hydrocarbon Molecules with Aliphatic Sidegroups  

NASA Astrophysics Data System (ADS)

The role of aliphatic side groups in the formation of astronomical unidentified infrared emission (UIE) features is investigated by applying the density functional theory to a series of molecules with mixed aliphatic-aromatic structures. The effects of introducing various aliphatic groups to a fixed polycyclic aromatic hydrocarbon (PAH) core (ovalene) are studied. Simulated spectra for each molecule are produced by applying a Drude profile at T = 500 K while the molecule is kept at its electronic ground state. The vibrational normal modes are classified using a semi-quantitative method. This allows us to separate the aromatic and aliphatic vibrations, and therefore provides clues to what types of vibrations are responsible for the emissions bands at different wavelengths. We find that many of the UIE bands are not pure aromatic vibrational bands but may represent coupled vibrational modes. The effects of aliphatic groups on the formation of the 8 ?m plateau are quantitatively determined. The vibrational motions of methyl (–CH3) and methylene (–CH2 –) groups can cause the merging of the vibrational bands of the parent PAH and the forming of broad features. These results suggest that aliphatic structures can play an important role in the UIE phenomenon.

Sadjadi, SeyedAbdolreza; Zhang, Yong; Kwok, Sun

2015-03-01

448

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

449

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

450

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

451

Controllable columnar organization of positively charged polycyclic aromatic hydrocarbons by choice of counterions.  

PubMed

A novel columnar organization of ionic complexes based on 9-phenylbenzo[1,2]quinolizino[3,4,5,6-fed]phenanthridinylium (PQP) has been achieved via ionic self-assembly. These complexes represent the first family of polycyclic aromatic hydrocarbons containing a large charged aromatic core with controllable columnar organization in both the crystalline and liquid-crystalline phases. The single-crystal structure of the ionic complex with a benzenesulfonate anion exhibits a staggered dimer arrangement of PQP cations that further establishes columnar superstructures. The use of sulfonate anions with long alkyl tails leads to well-ordered discotic columnar mesophases with an identical staggered packing of the PQP cations. PMID:19548673

Wu, Dongqing; Pisula, Wojciech; Enkelmann, Volker; Feng, Xinliang; Müllen, Klaus

2009-07-22

452

Mechanisms of interaction between polycyclic aromatic hydrocarbons and dissolved organic matters.  

PubMed

Binding of phenanthrene and fluorene to a number of humic and fulvic substances isolated from various sources as well as a commercially available humic acid, was investigated using a fluorescence quenching approach. The observed fluorescence quenching indicated by linear Stern-Volmer plots and high bimolecular quenching rate constant was induced by a static interaction process. A significant correlation of binding constants with aromaticity and polarity of dissolved organic matter (DOM) was observed. It is hypothesized that the binding of polycyclic aromatic hydrocarbons (PAHs) by DOM is due to both ?-? interactions and hydrophobic interactions. In addition, energy transfer from PAHs to DOM occurs because of the significant overlap between the absorbance spectra of DOM and emission spectra of PAHs. Thus, dipole-dipole interaction may also play an important role in the binding mechanism between PAHs and DOM. PMID:24117086

Wang, Huan Bo; Zhang, Yu Jun

2014-01-01

453

[Study on quantification assessment and odor fingerprint of volatile aromatic hydrocarbons from sewage treatment plant].  

PubMed

The malodorous volatile organic compounds (MVOCs) from a typical municipal sewage treatment plant in Guangzhou were detected and analyzed using thermal-desorption/GC-MS and electronic nose, respectively. The results showed that: (1) Aromatic hydrocarbons were the main malodorous volatile organic compounds of the sewage treatment plant, with concentrations ranging from 96.61 microg x m(-3) to 818.03 microg x m(-3), accounting for more than 50% of the total MVOCs, much higher than other MVOCs species. (2) Volatile aromatic hydrocarbons (VAH) in municipal sewage treatment plant were mainly from domestic wastewater, and the sludge treatment process played an important part in release of these pollutants. The total concentration of aromatic hydrocarbons emitted from each processing unit in a descending order was: the sludge dehydration room > sludge thickener > aeration tank > grille > biochemical pool> grit chamber. (3) rincipal component analysis (PCA) was able to distinguish the characteristic of odor emission from each processing unit, with the recognition index reaching 71% , and the PCA recognition index of simulated gases which simulated the VAH levels of different processes reached 94% , indicating that there was big difference among the srmll of the VAH emitted from different processes. (4) The comparison of the original odor fingerprint and simulated odor fingerprint measured by the sensor T70/2 showed that the original odor fingerprint was greater than the simulated odor fingerprint, and the correlation analysis indicated that the VAH had a great contribution to the odor fingerprint of each unit, and the contribution of VAH odor of the aeration tank tq the original odor fingerprint reached 0. 98. PMID:23914565

Guo, Wei; Wang, Bo-guang; Tang, Xiao-dong; Liu, Shu-le; He, Jie; Zhang, Chun-lin

2013-05-01

454

Mineralization of polycyclic and n-heterocyclic aromatic compounds in hydrocarbon-contaminated soils  

SciTech Connect

The comparative mineralization of eight polycyclic aromatic compounds in five soils collected from an abandoned coal tar refinery in eastern Ohio was determined. The soils showed differences only in total extractable hydrocarbon content of the soil chemical characteristics measured. The compounds studied included five polycyclic aromatic hydrocarbons (phenanthrene, anthracene, pyrene, and carcinogenic benz[a]anthracene and benzo[a]pyrene) and three N-heterocyclic aromatics (9H-carbazole, and carcinogenic 7H-dibenzo[c,g]carbazole and dibenz[a,j]acridine). Mineralization was measured by serum bottle radiorespirometry. Only phenanthrene, anthracene, pyrene, benz[a]anthracene, and carbazole were mineralized in the soils after 64 d. Two of the soils with eight to 15 times the hexane -extractable hydrocarbon content consistently showed more rapid initial rates and higher overall extents of mineralization compared to the other three soils. Overall extents of mineralization ranged from 38 to 55% for phenanthrene, 10 to 60% for anthracene, 25 to 70% for pyrene, background to 40% for benz[a]anthracene, and 25 to 50% for carbazole after 64 d. Extents of mineralization by indigenous soil microbiota appear to be more dependent on the chemical characteristics of the soil and not soil total biomass and activity. Cultures capable of degrading phenanthrene, anthracene, and pyrene were obtained following enrichment techniques. A Mycobacterium sp. capable of degrading these three compounds was isolated and reintroduced into two of the soils, resulting in mineralization enhanced above that of the indigenous soil microbial population. These data indicate that the future success of bioremediation methods relies on the characterization of environmental parameters affecting microbial degradation as well as the isolation of microbial populations that can reduce toxicity in the environment.

Grosser, R.J.; Warshawsky, D.; Vestal, J.R. [Univ. of Cincinnati, OH (United States)

1995-03-01

455

Interrelationship of Pyrogenic Polycyclic Aromatic Hydrocarbon (PAH) Contamination in Different Environmental Media  

PubMed Central

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

456

Evidence that Polycyclic Aromatic Hydrocarbons in Two Carbonaceous Chondrites Predate Parent-Body Formation  

NASA Technical Reports Server (NTRS)

Organic material in meteorites provides insight into the cosmochemistry of the early solar system. The distribution of polycyclic aromatic hydrocarbons (PAHs) in the Allende and Murchison carbonaceous chondrites was investigated using spatially resolved microprobe laser-desorption laser-ionization mass spectrometry. Sharp chemical gradients of PAHs are associated with specific meteorite features. The ratios of various PAH intensities relative to the smallest PAH, naphthalene, are nearly constant across the sample. These findings suggest a common origin for PAHs dating prior to or contemporary with the formation of the parent body, consistent with proposed interstellar formation mechanisms.

Plows, F. L.; Elsila, J. E.; Zare, R. N.; Buseck, P. R.<