Characterization of PM2.5-Bound Polycyclic Aromatic Hydrocarbons in the Ambient Air of Győr,Hungary

ABSTRACT

In Hungary, the nationwide monitoring of PM10-bound polycyclic aromatic hydrocarbons (PAHs) in ambient air is great importance for a number of reasons related to human health, the environment and compliance with European Union legislation. However, the measurement of PAH concentrations in PM2.5 aerosol fraction has not been carried out. Therefore, the concentration, distribution and sources of PM2.5-bound PAHs at different urban sites of Gy?r were investigated in a heating season. The total PAH concentrations (sum of 19 individual PAH compounds) ranged from 1.32 to 37.27 ng/m³ with the mean value of 10.54 ng/m³. The high molecular weight PAHs with 5 and 6 aromatic rings were the most abundant PAHs in PM2.5 aerosol samples, which averaged 82% of total PAHs. Using benzo(a)pyrene (BaP) equivalent approach on the concentration data of carcinogenic PAH species, BaP and indeno(1,2,3-cd)pyrene contributed the highest carcinogenic exposure equivalent (1.25 and 0.19 ng/m³ on average). However, the incremental lifetime cancer risk (ILCR) values for resident children and adults indicated low-potential cancer risk (ILCR < 10^?6). The source apportionment results reflected that the major sources of PAH compounds in the Gy?r atmosphere were fossil fuel combustion and vehicle emissions.     

Indoor Polycyclic Aromatic Hydrocarbon Concentration in Central India

The indoor burning of different materials like fuels, incense, mosquito coil, candles etc. results in generation of polycyclic aromatic hydrocarbons (PAHs) in an uncontrolled manner. The PAH, i.e., Benzo(a)pyrene (BaP) is considered as most toxic or carcinogenic and the toxicity of other PAHs is related to this compound. Therefore, the concentration and emission fluxes of polycyclic aromatic hydrocarbons (PAHs) emitted during burning of commonly used indoor materials, i.e., 15 fuels (i.e., biomass (BM), coal (C), cow dung (CD), kerosene (K)), 4 incense (IS) and mosquito coil (MC) in Raipur district, Chhattisgarh, central India is described. The samples were taken in September 2013 in indoor environments and respective smoke emitted were collected using high volume United State of America (USA) air sampler on quartz fiber filters. The concentration of total 13 PAHs (∑PAH₁₃) (i.e., phenanthrene, anthracene, fluoranthene, pyrene, benz(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)-pyrene, dibenz(ah)anthracene, benzo(ghi) perylene, indeno1,2,3-(cd)pyrene, and coronene) in particulate matter (PM₁₀) in the indoor air during burning of the fuels, IS and MC materials ranged from 367–92052 ng m^?3, 4089–14047 ng m^?3, and 66–103 ng m^?3 with mean values of 7767 ± 11809 ng m^?3, 9977 ± 4137 ng m^?3, and 74 ± 20 ng m^?3, respectively. The mean concentration of the ∑PAH₁₃ present in indoor environment is much higher than the WHO limit value of 1.0 ng m^?3. The sources and toxicities of PAHs are discussed.     

Determination of Averaged Long-term Air Concentrations of Semivolatile Polycyclic Aromatic Hydrocarbons: First Results

Abstract

Using our long-term sampling methodology presented previously, consecutive 14-day air samples of semivolatile polycyclic aromatic hydrocarbons (PAH) (from fluoranthene/pyrene to coronene) were collected over the time-span of nearly a whole year at a semi-rural site (Jülich) and quantified by GC-FID. As expected, concentrations were higher in winter [3 ng m^?3 for benzo[e]pyrene (BEP)] than in summer (0.4 ng m^?3 for BEP). However, normalized concentrations (to BEP =1) showed constant values for most PAH; thus, a largely stable PAH profile is obvious. Exceptions are benzo[a]pyrene and benz[a]anthracene: their concentrations normalized to BEP were lower in summer, indicating specific losses. Reasons for these losses are unknown as yet, although degradation reactions during atmospheric transport are a distinct possibility.     

POLYCYCLIC AROMATIC HYDROCARBONS ANALYZED IN RAINWATER COLLECTED ON TWO SITES IN EAST OF FRANCE (STRASBOURG AND ERSTEIN)

Polycyclic Aromatic Hydrocarbons (naphtalene, acenaphtene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]anthracene, chrysene, benzo[j]fluoranthene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenzo[a,h]anthracene, benzo[g,h,i]perylène, indeno[1,2,3-c,d]pyrene and coronene) have been consecutively analyzed in rainwater sampled in Strasbourg (urban site) and Erstein (rural site) between January 2002 and June 2003 and between April 2002 and June 2003 on a weekly basis respectively. For the sampling of rainwater, a wet-only rainwater sampler was used together with an open collector to take the measurements of precipitation.

PAHs in rainwater were extracted by using SPE cartridges and analyzed by HPLC-fluorescence following a method developed in the laboratory.

Mean concentrations of all PAHs (Σ 16 HAPs) varied between 0.15 and 79.60 ng·L^?1 in Erstein, and between 3.70 and 1596.45 ng·L^?1 in Strasbourg. Naphtalene, phenanthrene, fluoranthene, pyrene, chrysene, benzo[j]fluoranthne and benzo[a]pyrene were the most concentrated PAHs analyzed. Benzo[a]pyrene was frequently detected. Seasonal effects were observed with a maximum of concentrations of PAHs during cold periods. Some spatial influences were also reported. The calculation of some PAH ratios show that diesel exhaust could be the main source of PAHs in rainwater on the two sites.     

POLYCYCLIC AROMATIC HYDROCARBONS IN BALTIC SEA SEDIMENTS

Present concentrations of parent polycyclic aromatic hydrocarbons (PAHs) were studied in bottom sediments of the Baltic Sea. Sediments were collected in 2001 and 2002 from the Gulf of Finland, the Northern Baltic Proper, the Eastern Gotland Basin, the Southern Baltic Proper, and Kattegat. Parent PAHs were quantified by liquid chromatography with fluorescence detection. The sum of 13 PAHs in 1 cm slices in the first 5 cm varied between 64 and 5161 ng/g (dw) depending on the bottom type. The most contaminated area was in the Eastern Gotland Basin, and the most abundant PAH components found in sediments were fluoranthene, benzo[b]fluoranthene, benzo[ghi]perylene, and indeno[1,2,3-cd]pyrene. The studied PAHs were both pyrolytic and petrogenic in origin. In addition, the concentrations of indeno[1,2,3-cd]pyrene and benzo[ghi]perylene indicated a contribution from diesel engines, which may indicate pollution caused by the steadily increased shipping in the Baltic Sea.     

The Use of Spectrofluorimetry for Monitoring the Bioaccumulation and the Biotransformation of Polycyclic Aromatic Hydrocarbons in Daphnia magna

A rapid and direct spectrofluorimetric method was tested in order to monitor the bioaccumulation of PAHs in Daphnia magna in a control media. After exposure to water containing benzo[ a ]pyrene or fluoranthene, daphnids were put in solvent, sonicated, and filtered. The fluorescence spectrum observed in the filtrate was recorded. Results were compared to HPLC measurements of the same pools of organisms. In fluoranthene experiments, the fluorescence peak of the daphnid extract spectrum was linearly related to the PAH content as measured with HPLC. In benzo[ a ]pyrene experiments, other fluorescent compounds progressively appeared in the sample. They were assumed to be metabolites. A linear regression involving fluorescence intensities at two different wavelengths was necessary for a satisfactory correlation with HPLC measurements. A water extraction was performed to isolate metabolites. None or very few fluoranthene metabolites were isolated in the aqueous phase, whereas increasing benzo[ a ]pyrene metabolites were observed while the exposure time increased.     

Very Large PAH Products from Pyrolysis of Mixtures of Smaller PAHS

The larger PAHs produced through pyrolysis of small PAHs as large as pyrene or perylene have been studied previously by several other research groups.^1.2 In the current work, three larger PAHs (benzo[ghi]perylene, coronene, and ovalene) were pyrolyzed at 450 degrees for 16 hours. The reactions used either each PAH alone or binary mixtures of each with the others or with pyrene.     

IN VITRO INTESTINAL TRANSFER AND METABOLISM OF POLYCYCLIC AROMATIC HYDROCARBONS

Though polycyclic aromatic hydrocarbon (PAH) transfer through intestinal epithelium seems principally governed by transcellular diffusion, other mechanisms may interfere. Several studies suggest a PAH metabolism via CYP450, particularly in liver, but only few data are available regarding intestinal barrier. This in vitro work aimed at studying PAH metabolism and its consequences on the transfer in the intestinal epithelium according to molecule physicochemical properties. It used ¹⁴C-labeled benzo[a]pyrene, pyrene, and phenanthrene. Medium analysis proved a metabolism in intestinal cells for each PAH. Parallel metabolism appeared to play a positive role in the intestinal transfer of PAHs under different forms: ¹⁴C from benzo[a]pyrene, pyrene, and phenanthrene were respectively transferred 26, 4, and 2 times less when cells were incubated with CYP450 inhibitors. Generally speaking, the faster and the higher a PAH crosses intestinal barrier, the less metabolized it will be.     

Polycyclic Aromatic Hydrocarbons and Nitropolycyclic Aromatic Hydrocarbons in Atmospheric Particles and Soil at a Traffic Site in Hanoi,Vietnam

The concentrations of polycyclic aromatic hydrocarbons (PAHs) and nitropolycyclic aromatic hydrocarbons (NPAHs) in total suspended particulates (TSP) and soil were measured at a traffic site in Hanoi, a typical motorcycle city of Vietnam. TSP was collected using high-volume air sampler on Pallflex 2500QAT-UP membrane filters. PAHs and NPAHs were analyzed by high-performance liquid chromatography (HPLC) using fluorescence and chemiluminescence detectors, respectively. The average concentrations of total 10 PAHs and 10 NPAHs in soil varied from 3.4–43.7 ng g^?1 and from 112–780 pg g^?1 dry weight, respectively, which were much lower than those in TSP. The results showed that large part of the higher molecular weight PAHs in soil, especially benzo[ghi]perylene and benzo[b]fluoranthene came from the atmosphere. However, NPAHs profile showed a different pattern. 3-nitroperylene and 6-nitrochrysene were the most abundant NPAHs in soil, followed by 1-nitropyrene and 6-nitrobenzo[a]pyrene. The fate of NPAHs in soil varied depending on soil properties and chemical structure of NPAHs. The finding that the [NPAH]/[PAH] concentration ratios in soil were different from those in TSP could be due to bio-degradation and/or secondary formation of NPAHs in soil, depending on NPAHs properties.     

Determination of Polycyclic Aromatic Hydrocarbons in F-15J,C-130H,and F-4EJ Aircraft Exhaust

There are occupational health concerns at Japan Air Self-Defense Force bases in regard to the exposure of military flightline personnel to carcinogens in aircraft emissions, such as polycyclic aromatic hydrocarbons (PAHs). To characterize the PAHs in military aircraft emissions from different types of engines, aerosol and gas samples were separately collected downwind from aircraft with a turboprop engine (C-130H), turbojet (F-4EJ), and turbofan (F-15J). The gas-phase PAHs were determined by gas chromatography coupled to mass spectrometry and the aerosol-phase PAHs were determined by high-performance liquid chromatography with fluorescence detection. The F-4EJ engine was a source of naphthalene vapor and aerosol PAHs, including carcinogens such as chrysene, benzo (b) fluoranthene, benzo (k) fluoranthene, benzo (a) pyrene, dibenzo (a,h) anthracene, benzo (ghi) perylene, and indeno (1,2,3-cd) pyrene. These heavier (five and six-ring) PAHs were also included in the emissions from the F-15J with its newer, high-temperature F-100 turbofan engine, but the concentrations were approximately one-tenth of those in the F-4EJ. In contrast to these fighter aircraft, the C-130H was found to be a significant aerosol source of the lighter, three-ring (phenanthrene and anthracene) and four-ring (fluoranthene and pyrene) PAHs, but not the heavier ones. These results demonstrate that various aircraft are sources of PAHs in the military flightline environment.     

Distribution,Sources, and Risk of Polycyclic Aromatic Hydrocarbons in the Core Sediments from Baiyangdian Lake,China

The burial characteristics and risks of 16 polycyclic aromatic hydrocarbons (PAHs) in core sediments from Baiyangdian Lake were investigated through gas-chromato graphy/mass spectrometry. The total concentrations of the 16 PAHs ranged from 39.48–1877.75 ng g^?1. The low-molecular-weight PAHs (two- to three-ring PAHs) were the dominant species, contributing 40.10–92.18% to the total PAHs, with a mean of 71.01%. Based on the observed molecular indices and on principal component analysis, the PAHs inputs were initially dominated by biomass and coal combustion, and atmospheric deposition and surface runoff could be the major transport pathways. The contaminated source characteristics, hydrodynamic condition, and sediment textural composition are the key factors affecting the distribution and source of PAHs. By conducting a risk quotient analysis between specific PAH concentrations and their corresponding sediment quality values, the top layer sediments were found to have a potential biological impact and relatively high toxicity. However, such impact should have no impairment. The toxic potency of PAHs in Baiyangdian Lake could be described by using the toxic equivalent of benzo[a]pyrene.     

Seasonal Influence on Vapor-and Particle-Phase Polycyclic Aromatic Hydrocarbon Concentrations in School Communities Located in Southern California

Ambient concentrations of 15 vapor-and particle-phase (PM _2.5 ) polycyclic aromatic hydrocarbons (PAHs), listed by the US EPA as priority pollutants, were measured between July 2002 and November 2003 in six Southern California communities participating in a multi-year chronic respiratory health study of schoolchildren. The communities were geographically distributed over two hundred kilometers, extending from Long Beach in coastal Los Angeles, to high mountain areas to the north and west of the Los Angeles basin, and south into Eastern San Diego County. Seasonal and spatial variation in the atmospheric concentrations of PAHs is of interest because this class of compounds includes potent mutagens, carcinogens, and species capable of generating reactive oxygen species (ROS) that may lead to oxidative stress. Naphthalene accounted for 95% of the total PAH mass; annual averages ranged from 89 to 142 ng m ^{? 3} . Benzo[ghi]perylene (BGP) and the pro-carcinogen benzo[a]pyrene (BAP), present almost exclusively in the particle-phase, ranged respectively from 38 to 231 pg m ^?3 and 75 and 111 pg m ^{? 3} , with the highest values observed in Long Beach, a community with a high volume of seaport-related activities, and Lancaster, a commuter dormitory community. A considerable increase in the particle-phase PAH concentration, relative to the vapor-phase, was observed as ambient temperature decreased. Cold/hot season ratios for PAHs in PM _2.5 averaged 5.7, reaching 54 at Long Beach. The presented data underscore the importance of seasonal variations on atmospheric PAH concentrations. These observations are relevant to future interpretation and analysis of community-scale human health effects research.     

POLYCYCLIC AROMATIC HYDROCARBONS IN BALTIC SEA BIVALVES

Concentrations of parent polycyclic aromatic hydrocarbons (PAHs) in the bivalves Macoma balthica and Astarte borealis were studied as an indication of the state of the Baltic Sea. Samples were collected between 1999 and 2001 from the Gulf of Finland, the Eastern Gotland Basin, and the Southern Baltic Proper. PAHs were quantified by liquid chromatography with fluorescence detection. The sum of 12 PAHs varied between 44 and 298 ng/g (ww), with the most contaminated bivalves found in Hanö Bight (the Bornholm basin). High-molecular-weight PAHs predominated among the PAHs. The PAH profiles of M. balthica differed from those determined in sediment from the same area. Both pyrolytic and petrogenic origins were indicated. Toxic equivalency factors evaluated as benzo[a]pyrene equivalents (BaPEs) were used to assess the PAH contamination. BaPEs were higher than values for M. balthica found in the southern part of the Gulf of Finland in 1995 and much lower than values measured in 1987 after the most serious oil spill in the Gulf of Finland in the past 25 years.     

Analysis of Polycyclic Aromatic Compounds in Soil Samples Using Laser-Induced Phosphorimetry

Abstract

The analysis and spectral characteristics of several polycyclic aromatic hydrocarbons (PAHs) have been investigated by Laser-Induced Solid-Surface Room Temperature Phosphorimetry (LI-SSRTP). These PAHs included phenanthrene, chrysene, 1,2 benzofluorene, 2,3 benzofluorene, pyrene, coronene, 1,2,3,4 dibenzanthracene, benzo(a)pyrene, benzo(e)pyrene, and benzo(g, h, i)perylene. A nitrogen laser was employed as the excitation source at 337 nm. Filter paper treated with UV irradiation for background reduction was used as the solid substrate. Thallium(I)acetate was employed as a phosphorescence enhancer. Absolute limits of detection in the picogram level were obtained for all the PAHs, improving SSRTP levels of detection by three orders of magnitude. Finally, the proposed method was tested with a PAH contaminated soil sample. Detection of several PAHs at the nanogram level was easily performed, showing the potential of LI-SSRTP to the analysis of samples of environmental concern.     

THE SIGNIFICANCE OF POLYCYCLIC AROMATIC HYDROCARBONS AS ENVIRONMENTAL CARCINOGENS. 35 YEARS RESEARCH ON PAH—A RETROSPECTIVE

In vivo studies with laboratory animals as well as in vitro studies with bacteria and mammalian cell cultures have demonstrated that the mutagenic and/or carcinogenic properties of numerous PAHs require metabolic transformation. Metabolism of PAHs has been explored in vitro using cellular microsomal fractions, mammalian cell cultures and later genetically engineered cells expressing cytochromes P450 from several species including humans.

Balancing the carcinogenic potential of some environmental matrices (vehicle exhaust, condensate of hard coal combustion effluents, cigarette smoke condensate, used motor oil) after separation into sub-fractions evidenced that the carcinogenic effect may be attributed almost exclusively to PAH. Mixtures of well-known carcinogenic PAH in concentrations as present in these matrices, however, did not explain the total biological effect. Thus, it had been speculated that either very potent unknown carcinogens are still hidden in the PAH fraction, or that synergistic effects (enzyme induction) play a significant role.

In parallel to these carcinogenicity studies, the metabolism of various PAHs has been investigated in rat liver microsomes from untreated animals as well as from animals pre-treated with inducers of cytochrome P450. It was found that even non-carcinogenic PAHs possess a significant inducing potential. Moreover, in several mammals a highly species-specific metabolism of PAH could be observed allowing a critical view to the extrapolation from animal experiments to the human situation. This was further confirmed by experiments with mammalian cell cultures including human ones as well as by metabolic studies with genetically engineered Chinese hamster V79 cells singularly expressing various cytochrome P450 enzymes from a number of different species (human, rat, mouse, fish). With these cell lines metabolic studies were carried out with a larger number of PAHs as substrates including phenanthrene, pyrene, chrysene, benzo[a]anthracene, benzo[c]phenanthrene, benzo[a]pyrene, dibenzo[a,l]pyrene, and benzo[c]chrysene.

Based on the metabolism results, analytical methods have been developed to determine urinary biomarkers of human PAH exposure. Human biomonitoring studies have been performed with different occupationally exposed individuals as well as within smokers and non-smokers of the general population. Endogenous PAH exposure levels and changes in the urinary excreted metabolic profile depending on exposure level have been determined.     

Characterization of Gaseous and Particulate Polycyclic Aromatic Hydrocarbons in Ambient Air of Delhi,India

Three seasonal sampling campaigns were undertaken at an urban site of Delhi for collection of PAHs in particulate and gas phase. Sampling was done by using modified Respirable Dust (PM ≤10μm) sampler attached with polyurethane foam (PUF) plugs and compared with conventional Respirable Dust (PM ≤10 μm) sampler. Total 16 EPA PAH (gaseous + particulate) were determined by Gas Chromatograph-Mass Spectrophotometer (GC-MS). The 3-ring PAH constitutes approximately 90% of the gaseous PAHs with phenanthrene, fluoranthene, acenapthylene, and acenaphthene being the most abundant gaseous PAHs. PAHs with 4- to 6- rings accounted for 92%, 87% and 78% in samples collected during winter, summer and monsoon season respectively. Gaseous PAHs, particulate PAHs and total PAHs were higher during winter as compared to summer and monsoon seasons. The contribution of particulate PAHs were 1.4, 2.1, and 2.5 times higher in winter, summer and monsoon, respectively than of gaseous PAHs. Indeno[123-cd]pyrene, benzo[ghi]perylene, dibenzo[ah]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene and chrysene were found to be the most abundant PAH compounds in the particulate PAHs during all the seasons. The result from application of diagnostic ratio suggests that the higher particulate PAHs emissions were predominantly associated with vehicular emissions along with emissions from biomass burning during winter season.     

DETERMINATION OF DIBENZO[A,L]PYRENE AND OTHER FJORD-REGION PAH ISOMERS WITH MW 302 IN ENVIRONMENTAL SAMPLES

Polycyclic aromatic hydrocarbons (PAHs) occur in the environment as complex mixtures including compounds with mutagenic and carcinogenic activity. The PAH profile routinely determined in environmental samples at present encompasses isomers with molecular weight (MW) not greater than 300. However, PAHs with MW >300 have been demonstrated for several matrices to contribute up to 50% of the total activity when tested for carcinogenicity in experimental animals. Recent studies indicate that among the dibenzopyrenes with MW 302 dibenzo[a,l]pyrene, possessing a fjord region, is by far the most carcinogenic PAH hitherto identified. To further elucidate the environmental relevance of this compound we have applied the isotope dilution GC/MS technique as analytical procedure to determine this compound and the related fjord region PAH naphtho[1,2-a]- and naphtho[1,2-e]pyrene in various matrices. Identification was based on comparison of UV and mass spectra as well as retention times of authentic reference materials. Determination of these PAHs was achieved after clean-up by several chromatographic steps including fractionation on a modified TABA-silica gel column. Quantitative data for matrices such as two cigarette smoke condensates, motor vehicle exhaust condensate (Otto-type engines), and tar-cork are reported. Based on toxic equivalent factors the relative contribution of dibenzo[a,l]pyrene (5.4–42.3%) to the total carcinogenic activity of a PAH profile will be discussed comprising 14 selected isomers (benzo[b]naphtho[2,1-d]thiophene; cyclopenta[cd]pyrene; benz[a]anthracene; chrysene/triphenylene; sum of benzo[b]-, benzo[k]-, and benzo[j]fluoranthene; benzo[a]pyrene; indeno[1,2,3-cd]pyrene; dibenz[a,h]anthracene; benzo[ghi]perylene; anthanthrene; dibenzo[a,l]pyrene determined in these matrices.     

Seasonal and Spatial Variation of Polycyclic Aromatic Hydrocarbons in Vapor-Phase and PM2.5 in Southern California Urban and Rural Communities

Fifteen priority polycyclic aromatic hydrocarbons (PAHs) were measured in two rural communities (Atascadero and Lompoc) located several hundred km northwest of Los Angeles and in four urban communities 40–100 km downwind of Los Angeles (San Dimas, Upland, Mira Loma, and Riverside), during all seasons, from May 2001 to July 2002. PM_2.5 and vapor-phase PAHs were collected, on prebaked quartz fiber filters and PUF-XAD-4 resin, respectively, at 113 LPM, during 24 h periods, every eighth day, and quantified by HPLC-Fluorescence. At all sites vapor-phase PAHs contained > 99.9% of the total PAH mass and were dominated by naphthalene (NAP), which varied from about 60 ng m ^{? 3} in Lompoc, a community with light traffic, to ～580 ng m ^{? 3} in Riverside, a community traversed by ～200,000 vehicles day^{? 1}. During summer pollution episodes in urban sites, NAP concentrations reached 7–30 times annual averages. Except for summer episodes, concentrations of low MW PAHs showed small seasonal variations (～2 times higher in winter). Similar concentrations of particle-phase PAHs were observed at all sites except for Lompoc. Benzo[ghi]perylene (BGP), a marker of gasoline exhaust emissions, showed the highest concentration among particle-phase PAHs, varying from 23.3 pg m^?3 in Lompoc to 193 pg m^?3 in Mira Loma. Benzo[a]pyrene and indeno[1,2,3-cd]pyrene, found exclusively in the particle phase, were much higher in urban sites (～40–100 pg m^?3), than in Lompoc (～12 pg m^?3). Winter particle-phase PAHs were 2 to 14 times higher than summer levels. Particle-phase PAHs were negatively correlated with mean air temperature in urban sites (r = ?0.50 to ?0.75), probably resulting from surface inversions occurring during winter. The data suggest that in Southern California vehicular exhaust emissions are a major contributor to particle-phase PAHs.     

Estimation of Indoor Air PAH Concentration Increases by Cigarette,Incense-Stick,and Mosquito-Repellent-Incense Smoke

Smoke from cigarette smoking and burning of incense sticks and mosquito-repellent incense, which is particularly used in summer, are thought to be primary factors of indoor air pollution by polycyclic aromatic hydrocarbons (PAHs) in Japanese houses. In this study, these respective smokes as indoor air pollutants were evaluated by quantifying their particulate matter (PM) and 7 PAHs. PM and PAHs in smoke from 5 popular brands of Japanese cigarettes were collected on the glass fiber filter by the international smoking mode. PM was quantified by weighing the filter before and after trapping them. PAHs were analyzed by HPLC after extracting the filter with ethanol/benzene (1:3, by vol.). Similarly, evaluation of smoke respectively generated by natural burning of 4 brands of incense sticks and 3 brands of mosquito-repellent incenses was also conducted. As the results of these experiments, the average concentrations of PM and benzo[a]pyrene in a 35 m³ closed room were estimated to increase 1630 μg/m³ and 8.2 ng/m³, respectively, by smoking of 3 cigarettes; 1320 μ/m³ and 4.1 ng/m³, respectively, by burning of 2 incense sticks; and 2510 μg/m³ and 17.3 ng/m³, respectively, by burning of 8 cm of mosquito-repellent incense.     

Aerobic biodegradation and inhibition kinetics of poly‐aromatic hydrocarbons (PAHs) in a petrochemical industry wastewater in the presence of biosurfactants

BACKROUND: In Izmir, Turkey, wastewaters from the petrochemical industry are treated using conventional activated sludge systems. A significant proportion of poly‐aromatic hydrocarbons (PAHs) with high‐molecular weights remains in this treatment system and inhibits the biological activity. Biosurfactants increase PAHs degradation by enhancing the solubility of the petroleum components. The aerobic inhibition kinetics of PAHs has not previously been investigated in the presence of biosurfactants for a real petrochemical industry wastewater. RESULTS: Among the kinetic models used (Monod‐type, zero, first‐order and second‐order) it was found that the Monod kinetic was effective for describing the biodegradation of PAHs in petrochemcal industry wastewater in the presence of three biosurfactants, namely Rhamnolipid (RD), Surfactine (SR) and Emulsan (EM) in an aerobic activated sludge reactor (AASR). The maximum PAH removal rate (R_max) and specific growth rate of PAH degrading bacteria (µ_max) increased, while the half saturation concentration of PAH (K_s) decreased at 15 mg L^?1 RD concentration compared with the control without biosurfactant at a sludge retention time (SRT) of 25 days. CONCLUSION: PAH oxidation is typified by competitive inhibition at RD concentrations > 15 mg L^?1 resulting in increases in K_s values with PAH accumulation. Low inhibition constant (K_ID) values reflect difficulties in the metabolizability of PAHs. Metabolite production decreased at RD = 25 mg L^?1 in the PAHs indeno (1,2,3‐cd) pyrene (IcdP), flourene (FLN), phenanthrene (PHE) and benzo(a)pyrene (BaP). Copyright © 2011 Society of Chemical Industry