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Comparative distribution of eight polycyclic aromatic hydrocarbons in airborne particulates collected by conventional high-volume sampling and by size fractionation [J]
Abstract
Airborne particulate samples were collected by a conventional high-volume sampler and by an Andersen cascade impactor on 3 to 5 days in each month over a period of 1 year at two sampling sites in Hamilton, Ontario, a city containing a large concentration of iron and steel manufacturing facilities. Eight individual polycyclic aromatic hydrocarbons (PAHs) were separated and analyzed quantitatively by thin-layer chromatography and fluorescence spectrophotometry, using internal standards. The size-fractionated samples contained much higher amounts of the soluble organic extracts than the corresponding extracts in the high-volume samples. Substantially higher levels of PAHs were also found in the cascade impactor samples. Data are presented on the distribution of the weight PAHs in five size classification ranges, seasonal influences on PAH levels, and comparisons of the much higher Hamilton PAH levels over corresponding concentrations reported for New York City and Los Angeles.
... In fact, it would appear that for the periods in question, Sydney is analogous to Hamilton, Ontario, which is an industrial city containing a large concentration of iron and steel manufacturing facilities. It is interesting to note that in the results presented by Katz and Chan (1980) (from which the Hamilton, Ontario, data for Table 4 has been abstrated) the most plentiful of the eight PAHs that these authors quantitatively determine is benzo[ghi]perylene (BghiP), where figures from a low of 1.62 to a high of 19.32 ng/m3 appear in their tables of results, and with annual averages of 15.19 and 10.55 ug/m3 being quoted. In the same work (Katz and Chan, 1980) the next most plentiful compound is BaP, and this is followed by BeP (benzo[e]pyrene. ...
... It is interesting to note that in the results presented by Katz and Chan (1980) (from which the Hamilton, Ontario, data for Table 4 has been abstrated) the most plentiful of the eight PAHs that these authors quantitatively determine is benzo[ghi]perylene (BghiP), where figures from a low of 1.62 to a high of 19.32 ng/m3 appear in their tables of results, and with annual averages of 15.19 and 10.55 ug/m3 being quoted. In the same work (Katz and Chan, 1980) the next most plentiful compound is BaP, and this is followed by BeP (benzo[e]pyrene. ...
... The modifications which are being introduced into the analytical procedure (while retaining TLC as the basic method) is to adopt ultrasonic extraction . of the original sample, the N,N-dimethylformamide-toluene extraction of the PAHs from the filtrate of the ultrasonic extraction operation described by Flessel et al. (1980) , and to improve the reliability of the re-solution of the dry PAHs into 100 uL or so of a suitable solvent prior to spotting the TLC plates. Two dimensional or double development of the TLC plates as described by Mainwaring and McGuirk (1977) and Katz and Chan (1980) may be used to obtain better segregation of compounds. It is hoped that the suitability of a spectrofluorometer with a TLC plate scanner can be assessed for the final quantitative measurements. ...
... If the concentrations measured on the 6th of March are excluded, as this sample was collected during a major dust storm episode in Kuwait, the mean (and range) in TSP that is typical for this site would be 1040 (140-2750) lg/m 3 . The TSP concentrations in this study were higher than those reported in Chicago (27.7 lg/m 3 ) and Lake Michigan in the USA (Offenberg and Baker 1999); Mumbai (119-216 lg/m 3 ), (Venkataraman et al. 1999); rural Taiwan (182-238 lg/m 3 ) (Wu et al. 2006); Thessaloniki in Greece (243 lg/m 3 ) (Chrysikou et al. 2009); and in Hamilton, Ontario Canada (58-121 lg/m 3 ) (Katz and Chan 1980). These high TSP values measured in Kuwait may be due, in part, to the fact that Kuwait is a desert country where high-energy winds often result in localized or regional dust storms. ...
DATA of Aerosol Robotic Network (Aeronet) stations and Ozone Monitoring Instrument (OMI) were obtained to get valuable and reliable information about the occurrence of dust events. In addition to Total Ozone Mapping Spectrometer (TOMS) provide informative and long dust events record.
To analyze the dust time series, monthly, annual and seasonal linear trends are applied to the dust time series. This is achieved by summing the total number of dusty hours for each month and then the total number of dusty days for the month is calculated.
Dust trend analysis includes; annual, winter, spring, summer and autumn with the rate of change.
Dust frequency of seasons in days/season before and after sorting in a descending manner from 1984 to 2013.
Satelliteimagesuse for PM2.5 Estimation and concentrations
Remote sensing-based measurements
Calibration of Field and Laboratory Equipment.
Particle concentrations in different size ranges and the total suspended particulate matter in the air in Kuwait.
Dust deposition rates were monitored and analyzed in Kuwait at the northern ArabianGulf to estimate quantities of fallen dust within major eight dust trajectories in the ArabianGulf.
Kuwait is surrounded by five major sources of dust rather than intermediate dust source areas that are listed.
Satelliteimages from 2000 to 2010 were used to identify major dust trajectories within seven major deserts in the world.
... If the concentrations measured on the 6th of March are excluded, as this sample was collected during a major dust storm episode in Kuwait, the mean (and range) in TSP that is typical for this site would be 1040 (140-2750) lg/m 3 . The TSP concentrations in this study were higher than those reported in Chicago (27.7 lg/m 3 ) and Lake Michigan in the USA (Offenberg and Baker 1999); Mumbai (119-216 lg/m 3 ), (Venkataraman et al. 1999); rural Taiwan (182-238 lg/m 3 ) (Wu et al. 2006); Thessaloniki in Greece (243 lg/m 3 ) (Chrysikou et al. 2009); and in Hamilton, Ontario Canada (58-121 lg/m 3 ) (Katz and Chan 1980). These high TSP values measured in Kuwait may be due, in part, to the fact that Kuwait is a desert country where high-energy winds often result in localized or regional dust storms. ...
Brunauer, Emmett, and Teller (BET) test were applied to dust samples in which samples (BET) surface area is highly related to the roundness of dust particles. The higher angularity and low roundness of the dust particles show a higher (BET) surface area. The roundness is also related to the particlesize distribution and mineralogical composition.
The electrical conductivity test relates very well with the chemical and physical properties of dust samples in the transmission of an electrical current.
The organic matter content was measured using the ignition method and the pH of the samples was recorded.
Maps of the distribution of high and low BET concentrations, electrical conductivity EC, organic matter content, pH.
... If the concentrations measured on the 6th of March are excluded, as this sample was collected during a major dust storm episode in Kuwait, the mean (and range) in TSP that is typical for this site would be 1040 (140-2750) lg/m 3 . The TSP concentrations in this study were higher than those reported in Chicago (27.7 lg/m 3 ) and Lake Michigan in the USA (Offenberg and Baker 1999); Mumbai (119-216 lg/m 3 ), (Venkataraman et al. 1999); rural Taiwan (182-238 lg/m 3 ) (Wu et al. 2006); Thessaloniki in Greece (243 lg/m 3 ) (Chrysikou et al. 2009); and in Hamilton, Ontario Canada (58-121 lg/m 3 ) (Katz and Chan 1980). These high TSP values measured in Kuwait may be due, in part, to the fact that Kuwait is a desert country where high-energy winds often result in localized or regional dust storms. ...
This open access book serves as an atlas of deposited dust and dust storms in Kuwait in relation to local and global regions. It features a wealth of maps and images of dust storm trajectories in the region, together with detailed descriptions of the chemical and physical properties of fallen dust, including the amount, particle size, statistical parameters, spectra absorption, dust mineralogy, trace and major elements, organic matter, associated pollen, and radionuclides and connected pollutants. Given its scope, the book is a valuable resource for a broad range of researchers, including geologists, chemists, environmentalists, botanists, air quality specialists, nanotechnology scientists, and solar energy experts.
... If the concentrations measured on the 6 th of March were excluded, as this sample was collected during a major dust storm episode in Kuwait, the mean (and range) in TSP that is typical for this site would be 1040 (140 to 2750) g/m 3 . The TSP concentrations in this study were higher than those reported in Chicago (27.7 g/m 3 ) and Lake Michigan in the United States (Offenberg and Baker, 1999), (Chrysikou et al., 2009), and in Hamilton, Ontario Canada (58–121 g/m 3 ) (Katz and Chan, 1980). These high TSP values measured in Kuwait may be due in part, to the fact that Kuwait is a desert country where high-energy winds often result in localized or regional dust storms. ...
... During the heating season in autumn and winter, pyrolitic PAHs are released in substantial amounts into the atmosphere as smoke from burning coal and wood in domestic heating systems or from heating plants (Baumard et al., 1999;Kautenburger and Muller, 1996;Simkova et al., 1996). For example, >5-time increase in PA H levels in winter was noted in the USA and Germany relative to summer because of organic combustion in cold months (Greenberg et al., 1985;Katz and Chan, 1980;Yang and Baumann, 1995). What is more, in winter months a marked increase (4-10 fold) of PA H emissions from motor vehicles is noted in colder periods (Bjorseth and Ramdahl, 1985). ...
Mussels from the Mytilus edulis complex were used as biomonitors for two groups of organic pollutants: polychlorinated biphenyls (PCBs, congeners: 28, 52, 101, 118, 138, 153 and 180) and polycyclic aromatic hydrocarbons (PAHs, naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benz(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, indeno(1,2,3-cd)pyrene, dibenz(a,h)anthracene, benzo(g,h,i)perylene) at 17 sampling sites to assess their relative bioavailabilities in coastal waters around Europe. Because of the temporal differences in PCBs and PAHs concentrations, data were adjusted using Seasonal Variation Coefficients (SVC) before making large-scale spatial comparisons. The highest concentrations of PCBs were found near estuaries of large rivers flowing through urban areas and industrial regions. Elevated bioavailabilities of PAHs occurred in the vicinity of large harbors, urban areas, and regions affected by petroleum pollution as well as in some remote locations, which indicated long-range atmospheric deposition.
... Although the nuclei mode, consisting of nanometer-scale particles with diameters of 5-50 nm, accounts for only 1-20% of total particle mass, it includes more than 90% of all particles. 70-90% of the particles that have a diameter that is smaller than 5 μm can be inhaled by humans (Katz et al., 1980) and accumulate in the respiratory bronchi and pulmonary alveoli, causing respiratory diseases (Voutsa and Samara, 2002;USEPA, 2002;Health Effects Institute, 2002). As fine particles (D p < 2.5 μm) have a higher surface area-to-volume ratio than coarse particles (2.5 μm < D p < 10 μm), PAHs can be more easily adsorbed onto fine particles and nanometer particles; therefore, if the mass concentrations of the coarse and fine particles are equal, then the fine particles will have a higher PAH-toxicity than the coarse particles (Kahandawala et al., 2004;Westerdahl et al., 2005). ...
This study investigates the size distribution of nano/ultrafine particle-bound PAHs (polycyclic aromatic hydrocarbons) and the PAH-associated carcinogenic potency/cytotoxicity of the exhaust from a generator that is fuelled with D100 (pure petroleum diesel) and S20 (v/v = 20% soy-biodiesel/80% D100) and operated at stable energy output loads (0 and 3 kW). A micro-orifice uniform deposit impactor (MOUDI) and a Nano-MOUDI (with aerodynamic diameters of 0.01– 18 μm) were used to collect PM samples. The cytotoxicity of the organic solvent extracts of PM samples to the human male monocytic cell strain (U937) was evaluated using the MTT (3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide) method. The results indicate that at both loads, using S20 in place of D100 effectively reduced the emissions of DEPs, PAHs in the DEPs, and PAHs-associated BaP eq ; furthermore, the unit mass cytotoxicity of ultrafine particles and nano-particles in the DEPs was also lowered (by an average of 52.6%). Therefore, soybean biodiesel (S20) can be used as an alternative fuel to petroleum diesel to reduce the hazards of emissions from diesel engines to human health.
... In Hamilton, Ontario, the total particulate PAHs ranged between 87% and 95% and were found on particle sizes of 1.1 µm<D<7.0 µm (Katz and Chan, 1980). The relatively high proportion of particulate PAHs (63% to 85%) measured in London were found in aerosols with aerodynamic diameters of less than 1.1 µm, and up to 95% of particulate PAHs in London were associated with particles under 3.3 µm in diameter (Baek et al., 1991). ...
Along with rapid economic growth and enhanced agricultural productivity, particulate matter emissions in the northern cities of Thailand have been increasing for the past two decades. This trend is expected to continue in the coming decade. Emissions of particulate matter have brought about a series of public health concerns, particularly chronic respiratory diseases. It is well known that lung cancer incidence among northern Thai women is one of the highest in Asia (an annual age-adjusted incidence rate of 37.4 per 100,000). This fact has aroused serious concern among the public and the government and has drawn much attention and interest from the scientific community. To investigate the potential causes of this relatively high lung cancer incidence, this study employed Fourier transform infrared spectroscopy (FTIR) transmission spectroscopy to identify the chemical composition of the PM2.5 collected using Quartz Fibre Filters (QFFs) coupled with MiniVolTM portable air samplers (Airmetrics). PM2.5 samples collected in nine administrative provinces in northern Thailand before and after the "Haze Episode" in 2013 were categorised based on three-dimensional plots of a principal component analysis (PCA) with Varimax rotation. In addition, the incremental lifetime exposure to PM2.5 of both genders was calculated, and the first derivative of the FTIR spectrum of individual samples is here discussed.
... Furthermore there is also still a lack of knowledge concerning the transfer of SVOCs from particles to leaves. For the reasons outlined above, information on the interception and retention behaviour of small particles (<10 mm) associated with SVOCs (Katz and Chan, 1980;Kaupp et al., 1994;Chen et al., 1996;Kaupp and McLachlan, 1999), together with an understanding of chemical movement from particles to leaf surfaces are of primary interest in evaluating the ability of different plant species to modify the overall atmospheric mass balance of particle bound SVOCs. Additionally, retention on leaf surface compartment can make the compounds more susceptible to photodegradation, while penetration into the epidermal cell wall or cytoplasm will enhance susceptibility to metabolism and protection from photodegradation. ...
Plants play a key role in removing particulate matter and their associated Semi-volatile Organic Compounds (SVOCs) from the atmosphere. Understanding the processes involved in particle capture by vegetation is essential to understand the interactions between SVOCs, particles and plants. In the present study Two Photon Excitation Microscopy (TPEM) was used to visualise particle matter uptake and encapsulation, together with its distribution on leaf/needle surface of different broadleaf (cornel and maple) and conifer species (stone pine). Phenanthrene accumulation, the number of particles associated with this compound and its migration from particles into the leaf cuticle was also identified and quantified. Species-specific deposition velocities were estimated to model temporal PM10 leaf/needle accumulation and to investigate the role of Planet Boundary Layer (PBL) height variation in influencing PM10 flux to plants. Particles at the leaf/needle surface were visualised to range in size from 0.2 to 70.4 μm, but cuticular encapsulation was negligible for particles larger than 10.6 μm, which were removed by a washing procedure. Phenanthrene concentration varied between ≈5 and ≈10 ng g−1 dw according to plant species and between ≈10 and ≈200 ng g−1 dw depending on needle age; this compound was visualized to migrate from particles into the adjacent leaf cuticle. Species-specific deposition velocity range between 0.57 and 1.28 m h−1 and preliminary simulations showed that the diel variability of PBL structure influenced the temporal PM10 flux and leaf/needle concentration, e.g. during daytime hours characterized by high PBL height, PM10 accumulated on cornel leaves was about 65% lower than the amount accumulated during night time. The capability of vegetation to capture particles from the atmosphere, retain, encapsulate them into the cuticle and release them to soil and/or lower biomass, highlighted the value of vegetation in removing pollutants from the atmosphere and influencing their environmental fate.
Description
The contents are divided into four sections: Industrial Hygiene Sampling and Analysis; Continuous Air Monitors and Portable Instruments; Passive Monitoring Devices; Chemical Characterization and Analytical Methods. The intent of the 1981 Boulder Conference upon which this publication is based was to review all aspects of air sampling and analysis in the areas of ambient air and workplace atmospheres.
Atmospheric concentrations of polycyclic aromatic hydrocarbons (PAHs) in Canada for 2000 and 2001 were evaluated to study particulate PAH profiles during cold weather periods. Ten sites from the National Air Pollutant Surveillance network and six sites from the aluminum industry network were selected to represent various site classifications. The following scale of decreasing concentration at fixed sampling stations was found: Söderberg aluminum production>iron and steel production>urban (traffic+domestic heating)>urban (traffic)>rural. The ratio of the cold divided by the warm weather period for each year suggested a clear input of PAHs from domestic heating at several sites. However, analysis of the relative proportions of particulate PAHs, comparison of benzo[e]pyrene relative abundance ratios and cluster analysis suggested that the site differences in the particulate PAH profiles were small with the exception of the aluminum smelter impacted locations. It appears that a relatively stable profile exists for atmospheric particulate PAHs between regions in Canada. The nature of this profile stability likely depends on the particle composition, individual PAH degradation patterns and intensity of the emission source(s). Overall, the results of this study suggest that a simple ratio of two or three PAHs may be insufficient to identify PAH emission sources at fixed sites and are a better indicator of the ageing process.
Aerosol mass size distributions of 14 polycyclic aromatic hydrocarbons (PAHs) were measured during 7 days in a zone of Las Palmas de Gran Canaria submitted to intensive car traffic. Mass median diameters range from 0.86 to 1.82 μm for particulate matter and from 0.38 to 1.31 μm for individual PAHs. Particulate matter mass size distribution exhibit a bimodal character with modal diameters in 0.08-0,3 μm and 3.8-7.4 μm. PAHs with molecular weights between 166 and 202 (fluorene, phenantrene, anthracene and fluoranthene) were distributed between the fine (aerodynamic diameter < 2 μm) and coarse (aerodynamic diameter > 2μm) aerosols. PAHs with molecular weights greater 228 were associated primarily with the fine aerosol fraction.
Respiratory functions of 607 workers from rubberprocessing unit were studied in relation to occupational exposure to various pollutants viz. suspended particulate matter, polycyclic aromatic hydrocarboin compound (PAH), sulphates and nitrates. The results showed significant decline in lung functions proportionately with the longer working duration and to the increased pollutant concentration of the various sections of the rubber factory. Workers in the compounding (mixing) unit were most affected as pollutant concentration found in this section was maximum; this was supported by the abnormal Xray findings.
A new spectral imaging approach, based on an imaging microscope coupled to a Fourier transform spectrometer, was applied for direct analysis of polycyclic aromatic hydrocarbons (PAHs) deposited onto solid matrices. Single crystals of several PAHs were grown and their fluorescence spectra were analyzed. The fluorescence characteristics, related to analytical reliable quantification of solid PAH compounds, were investigated. In particular, we have addressed the following parameters: (a) crystal-alignment effects upon the read-outs of the microscopic imaging set-up; (b) effects associated with either the crystal edge or the crystal surface originated fluorescence spectra; (c) inter-crystal self-absorption related processes. The understanding of these effects is important for a proper sampling of the PAHs and is essential for obtaining reliable quantification.
A porphyrin/peroxynitrite biomimetic system was used to study the metabolism of indeno[1,2,3-cd]pyrene (IND) induced by peroxynitrite. The metabolites were identified using high-performance liquid chromatography coupled with electro-spray ionization tandem mass spectrometry as OH-IND, IND-quinone and 2NO2-IND. By stopping the reaction at different stages, we discovered that IND was first transformed to IND-quinone and 2NO2-IND, which were then transformed to OH-IND. Mutation assays including Ames tests and cell transformation experiments showed enhancement of the mutagenicity after the activation by the peroxynitrite/Fe(III)porphyrin system. The results also showed that 2NO2-IND and IND-quinone played key roles in the mutagenicity of PAHs after metabolic activation.
Atmospheric samples were conducted from September 2001 to July 2002 with GPS-l PUF sampler in rural site to concentration distributions of gas/particle PCBs and to calculate dry deposition flux of PCBs. PCBs concentrations of gas/particle PCBs were 59.2948.83, 6.566.59 pg/㎥, respectively. Gas contribution (%) of total PCBs (gas + particle) was 90% which existed gas phase in the atmosphere. The particle contribution (%) of PCB congeners increased relatively more of the less volatile congeners with the highest chlorine number. The correlation coefficients (r) between total PCBs and temperature () showed negative correlation in - 0.62 (p
Atmospheric particle and PAH (Polycyclic Aromatic Hydrocarbons) mass size distributions in both a traffic intersection and a rural site were measured with two MOUDIs (Micro‐orifice Uniform Deposit Impactors) and a NRI (Noll Rotary Impactor) from June 1994 to June 1995 in southern Taiwan. In the ambient air of the traffic intersection, both the total PAHs and total particle mass were found to be with unimodal size distributions, while at the rural site, they were found to be with bimodal size distributions. Twelve PAHs were found to have a significant bimodal‐distribution: Nap, AcPy, Flu, PA, Ant, FL, CYC, BaA, BkF, DBA, BbC and BghiP. The remaining PAHs (Acp, Pyr, CHR, BbF, BeP, BaP, PER, IND, and COR) had a unimodal or unimodal‐like distribution. In the ambient air of the traffic intersection, the cumulative fraction of total PAHs in the particle size range below 1,2.5, 10 and 25 μm, in sequence, were 50.9%, 74.2%, 90.8% and 95.9%, respectively, while those values at the rural site, in sequence, were 38.3%, 56.4%, 85.7% and 94.0%, respectively. The Traffic/Rural ratio of BaP varied between 7.07 and 17.6 and averaged 11.2 in the fine particle mode; it varied between 5.32 and 16.9 and averaged 10.6 in the coarse particle mode. The high concentration of carcinogenic PAHs in the ambient air of the traffic intersection is a strong potential factor for inducing a high rate of lung cancer. The MMDo of total PAHs and total particle mass in the ambient air of the traffic intersection were 0.943 and 3.59 μm, respectively. However, these two values at the rural site were 1.67 and 2.03 μm, respectively. These results revealed that there was a larger amount of smaller particulates in the ambient air of the traffic intersection. Smaller particulates have more specific area and therefore allow more PAH mass to be adsorbed on them.
Airborne particles in fugitive emissions have been measured at a slagging fixed-bed coal-gasification pilot plant using lignite. Sampling was conducted during shutdown operations and opening of the gasifier following an aborted startup. Aerosol collected with a Sierra high-volume impactor was subjected to analysis by gas chromatography, mass spectrometry, and scanning electron microscopy; aerosol collected with an Andersen low-volume impactor was subjected to flameless atomic absorption analysis. The data show that the bulk of the trace organic material is associated with small particles: these data are similar to data on ambient air reported in the literature. Particle morphologies resemble those of fly ash from coal combustion, including smooth spheres, vesicular spheres, and crystalline material. Trace element size distributions are bimodal and resemble data for ambient air. Pb-containing particles are generally submicron, while particles containing Al, Fe, and other crustal species are mostly of supermicron size. Aluminum-based aerosol enrichment factors calculated from the lignite composition show that the composition of the aerosol resembles that of the coal, with the exception of modest enrichments of Mg, Na, As, and Pb in the submicron size range. Aerosol enrichment factors based on the earth's crustal composition are somewhat greater than those based on coal composition for several elements, suggesting potential errors in using crustal enrichment data to investigate chemical fractionation during aerosol formation.
Fugitive emissions from a slagging fixed-bed coal-gasification pilot plant were analyzed by flameless atomic absorption spectrophotometry, gas chromatography, and mass spectrometry for trace metal and trace organic species. Analysis of the size distributions of airborne particulate matter inside the plant showed an abundance of large metal-containing particles; outdoor distributions in the vicinity of the plant resembled the indoor distributions, suggesting the importance of the gasifier in influencing ambient air quality. This conclusion was further supported by identification of similar organic compounds inside and outside the plant. Trace element enrichment factors based on the earth's crustal composition were greater than those based on the composition of the lignite used in the gasifier, showing the importance of characterizing the proper source material when inverstigating chemical fraction during aerosol formation. Enrichments in the present study were much greater than those found in previous sampling during aborted start-up and cleaning procedures, where normal operating temperatures had not yet been reached. Both studies showed evidence of enrichment factors which decreased with increasing particle size. Although much of the airborne mass was associated with large particles having low respirability, the high concentrations of some metals indoors suggests that further assessment of potential occupational exposures is warranted.
A physical description of semi-volatile organic compounds (SVOCs) is given, both in terms of their characteristic nature in the atmosphere and the processes which control their deposition. The currently adopted methods used to measure the atmospheric concentrations of SVOCs have been summarised, along with their shortcomings. Techniques and associated problems have also been reviewed for measurements of atmospheric deposition. A summary has been given of the requirements necessary for a full assessment of atmospheric SVOCs and their deposition.
Plant uptake of semivolatile organic compounds (SOCs) occurs primarily from the atmosphere via one of three processes: equilibrium partitioning between the vegetation and the gas phase, kinetically limited gaseous deposition, or wet and dry particle-bound deposition. Each of these processes depends on different atmospheric concentrations, plant properties, and environmental variables. Hence, in interpreting measurements of SOCs in plants, it is imperative that the major process responsible for the accumulation of a given compound be known. Beginning with basic equations describing gaseous and particle-bound deposition to vegetation, a framework for identifying the major uptake process and further interpreting measurements of plant concentrations is developed. This framework makes use of the relative differences in accumulation behavior as a function of the octanol-air partition coefficient (K{sub OA}) of the chemical. The mathematical analysis leads to two interpretive tools, both log-log plots, one of the quotient of the vegetation and gas-phase concentrations vs K{sub OA} and one of the quotient of the vegetation and particle-bound concentrations vs the quotient of the particle-bound and gaseous concentrations. Each of these plots contains three distinct and easily recognizable segments, and each segment corresponds to one of the three deposition processes. When the experimental data are plotted and the three segments are identified, it is possible to determine the dominant uptake process for a given compound, and this in turn opens the door to further interpretation of the plant uptake behavior.
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 monitoring data. In the urban samples, PAH were distributed among aerosol size fractions based on molecular weight. PAH with molecular weights between 178 and 202 were approximately evenly distributed between the fine (aerodynamic diameter <2 {mu}m) and coarse (aerodynamic diameter >2 {mu}m) aerosols. PAH with molecular weights greater than 228 were associated primarily with the fine aerosol fraction. In the rural samples, low and high molecular weight PAH were associated with both the fine and coarse aerosols. Slow mass transfer by vaporization and condensation is proposed to explain the observed PAH partitioning among aerosol size fractions. 17 refs., 5 figs., 5 tabs.
Atmospheric concentrations of nineteen polycyclic aromatic hydrocarbons (PAHs) were determined in the particulate and vapour phases of samples collected during 24 hours in winter and summer 1990 from croatian urban, industrial and rural sites.An analytical procedure is described for a comprehensive determination of polycyclic aromatic hydrocarbons in air samples based on aerosol filtration through glass fiber filters and vapour phase adsorption on XAD-2 resin. Separation, indentification and determination of PAHs were performed by TLC, GC and GC-MS.Total concentration of PAHs in Kosnica (winter) was about three to four times (summer) higher than concentration of PAHs in Zavižan. The aerosol composition in Kosnica can be attributed to very high traffic near the sampling site. Concentrations of SO2 and NO2 and granulometric distribution of particulate matter were also measured.
This chapter discusses the adsorption of organic pollutants on solid aerosol surfaces. Migration of solid aerosols to areas with other types of organic and inorganic pollutants can create unexpected combinations of chemicals in the atmosphere. The composition of aerosols depends on the production mechanism and the chemical environment. Aerosols may be considered a complicated mixture of natural and anthropogenic chemical substances containing sulfates, soluble inorganic compounds, solid minerals, and carbon containing compounds. All components of solid aerosols—such as silica, alumina and other metal oxides, metal salts, carbonaceous parts in the presence of adsorbed inorganic anions, and long-chain organic compounds—possess surface and structural heterogeneities that play a dominant role in adsorption and reactions of organic pollutants on their surface, especially at low pressures. The polarizability of the adsorption sites on solid surface contributes to the total polarizability of the particles. The chapter also discusses the chemisorption and surface reactions of organic compounds on metal oxides. The Bronsted and Lewis acid–base sites are the main reaction sites of the inorganic oxide surfaces.
Environmental problems in huge cities have been related to a high demographic density and diverse industrial activities. Gasoline
and diesel exhaust, incinerators and industries’s stacks involved in combustion processes and forest and agriculture fires
are some of the main air pollution sources (Westerholm et al., 1992). Many organic, inorganic and radioactive chemicals, identified
as hazardous air pollutants (Kelly et al., 1994), are present in the urban atmospheres in a wide variety of compounds (Natusch,
1978).
A method for determination PAH's using GC‐ECD after derivatisation with bromine is presented. ECD is highly selective and sensitive for measuring bromo‐PAH's. The detection limits were improved up to two to three orders of magnitude compared with FID‐detection of underivatised PAH's.
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Aerosol characterization has been conducted in the vicinity of a copper smelter and a power plant since April 1983. Comparison of data indicates the following: There is only a slight difference in the concentrations of Al, Ca, Mg, Na, Fe, Mn and major ions in water‐soluble fractions between the two aerosols; Zn, Cu, Pb and Cd occur at higher concentrations in the vicinity of the copper smelter; the area around the power plant exhibits higher sulphate and chloride concentrations. Factor analysis shows that the aerosol under study can be considered to be composed of four or three different components. The power plant is a potential source of PAH emissions. The concentrations of PAH seemed to be higher in November/January than in May/June.
Atmospheric deposition across the air–sea interface is the main input route for persistent organic pollutants (POPs) to the marine environment and its ecosystems. The main processes contributing to air–sea exchange of POPs are diffusive vapour exchange, precipitation scavenging of vapours and particle-sorbed chemicals, and dry deposition with particles. Additional processes within the atmosphere and surface water affecting this exchange are aerosol–vapour partitioning, and partitioning and sedimentation in the water-column. These processes are discussed and recent findings are summarised. Commonly employed expressions used for describing these processes in models are presented, with a special focus on the influence of temperature and other seasonal parameters. Research gaps are identified which have to be addressed to gain a solid understanding of the environmental transport and distribution of POPs. This is needed to implement and evaluate the effectiveness of recent international agreements to protect the marine environment from the deleterious effects of POPs.
Air samples were taken in a rural area of Kyonggi-do of South Korea to investigate gas/particle concentration and partitioning. Gas/particle phase concentrations of polychlorinated biphenyls (PCBs) were measured over 48h periods from September 2001 to July 2002.The average contribution (%) of gas to particle was about 90%, which suggests that in the atmosphere PCBs predominantly existed in the gas phase. The correlation coefficients (r) between total PCBs and temperature (°C) showed negative correlation for particle phase and positive correlation for gas phase. The contribution (%) of PCB congeners to total PCBs in gas phase increased with decreasing chlorine substitution. The particle contribution (%) of PCB congeners increased for the less volatile congeners, i.e., those with the higher chlorine number. The coefficient of determination (R2) between log (Cparticle/Cgas) and logKOA was 0.86, which implies that heavier PCB congeners exist more in particle phase than gas phase compared to lighter PCBs. Partitioning of PCBs between gas and particle phases correlated well with the sub-cooled liquid vapor pressure (PoL) and the octanol–air partition coefficient (KOA) for all samples, but the coefficient of determination (R2) differed for each season.
The magnetic susceptibility of respirable urban airborne particulate and the mutagenic potency and organic content of extracts prepared from these particles are both related to mobile and stationary combustion processes. Analyses of the organic extracts prepared from these particulate samples showed the presence of certain polycyclic aromatic hydrocarbons (PAH), certain keto-PAH and thia-PAH. The enhanced magnetic signatures of air particulate material collected in an urban environment are directly related to the presence of magnetite-rich spherules which are likely to have been produced by the oxidation of pyrite to magnetite during the combustion process.A total of 62 filters collected between May 1990 and June 1991 at an air quality monitoring station in Hamilton, Ontario were examined. A plot of magnetic susceptibility of these filters and the mutagenic potencies of the organic extracts prepared from these filters in the Salmonella/microsome assay show a significant correlation. Neither magnetic susceptibility nor mutagenicity show a similar simple direct relationship to particulate loading.Plots of wind direction vs wind speed indicate that the highest mutagenicity and susceptibility levels are predominantly associated with (a) easterly derived winds, (b) low to moderate wind velocities, and (c) enhanced levels of SO2 and NO2. In contrast, low mutagenicity and susceptibility levels are intimately associated with (a) southwesterly derived winds, (b) moderate to high wind velocities, and (c) the presence of high ozone levels which accompany higher summer temperatures. These observations suggest that rapid magnetic susceptibility measurements could be used to pre-select filters for more extensive evaluations such as organic compound analyses or biological assays.
The respiratory health of 726 workers in a rubber processing factory has been investigated. The values of the forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1) and the ratio of FEV1/FVC in workers were inversely related to the total suspended particulate matter (TSP) and benzo(a)pyrene present in the workplace air. Statistically significant decrements in ventilatory function occurred following prolonged exposure as assessed by the duration of working in the plant. When the different sections of the factory were consid ered, workers in the compounding section were most affected, which was asso ciated with the highest exposures to TSP and benzo(a)pyrene. On chest X-ray, 16 % of the workers from the compounding section exhibited radiographic abnormalities. Of 7 possible factors thought likely to be related to the effects on pulmonary function, only TSP and the concentration of benzo( a)pyrene in the respirable fraction of particulates resulted in a statistically significant asso ciation in a multiple regression analysis.
To better assess the applicability of nitromethane as a selective quenching agent for alternant versus nonalternant polycyclic aromatic hydrocarbons in HPLC, TLC, and HPTLC analysis, the authors measured the effect that it has on the fluorescence emission behavior of 96 different polycyclic aromatic hydrocarbons dissolved in binary toluene/acetonitrile solvent mixtures. Results of these measurements revealed that the [open quotes]selective quenching[close quotes] rule is obeyed for the vast majority of PAHs, with the coronene derivatives being the only major exceptions. Fluorescence emission spectra are also reported for benzo[g]chrysene, naphtho[2,3g]chrysene, 4H-benzo[c]cyclo-penta[mno]chrysene, dibenzo[ghi,mno]fluoranthene (commonly called corannulene), rubicene, diacenaphtho[1,2j:1',2']fluoranthene, 10-methyl-benzo[b]fluoranthene, 3-methoxybenzo[k]fluoranthene, and 3-hydroxy-benzo[k]fluoranthene in organic nonelectrolyte solvents of varying polarity. Calculated emission intensity ratios failed to vary systematically with solvent polarity, and all nine of the aforementioned solutes were thus classified as nonprobe molecules. 63 refs., 4 figs., 2 tabs.
Dry deposition and air sampling were undertaken, simultaneously, in the ambient air of an urban site and a petrochemical-industry (PCI) plant by using several dry deposition plates and PS-1 samplers from January to May 1994 in southern Taiwan. The dry deposition plate with a smooth surface was always pointed into the wind. Twenty-one polycyclic aromatic hydrocarbons (PAHs) were analyzed by a gas chromatography/mass spectrometer (GC/MSD). The dry deposition flux of total-PAHs in urban and PCI sites averaged 166 and 211 μg/m²·d, respectively. In general, the PAH dry deposition flux increased with increases in the PAH concentration in the ambient air. The PAH pattern of dry deposition flux in both urban and PCI sites were similar to the pattern measured by the filter of the PS-1 sampler and completely different from the PAH pattern in the gas phase. The higher molecular weight PAHs have higher dry deposition velocities. This is due to the fact that higher molecular weight PAHs primarily associated with the particle phase are deposited mostly by gravitational settling, while the gas phase PAHs were between 0.001 and 0.010 cm/s, only the lower molecular-weight PAHs--Nap and AcPy--had a significant fraction of dry deposition flux contributed by the gas phase. All the remaining higher molecular-weight PAHs had more than 94.5% of their dry deposition flux resulting from the particle phase. This is due to the fact that higher molecular weight PAHs have a greater fraction in the particle phase and the dry deposition velocities of particulates are much higher than those of the gas phase.
The gas-particle partitioning and particle size distributions of airborne PAH in Bangkok urban air were investigated using an 8 stage size fractionating cascade impactor (Andersen “low volume” sampler) and a downstream XAD-2 adsorbent tube for sample collection. Nine PAH classified as carcinogenic and co-carcinogenic compounds-Pyrene (PYR), Benz(a)Anthracene (BaA), Benzo(e)Pyrene (BeP), Dibenz(a,c)Anthracene (DBacA), Benzo(k)Fluoranthene (BkF), Benzo(a)Pyrene (BaP), Dibenz(a,h)Anthracene (DBahA), Benzo(ghi)Perylene (BghiP) and Trimethylcholanthrene (3MC) - were quantified. The lower molecular weight (MW) PAH such as PYR, BeP and BaA were present mainly in the gaseous phase (80%, 40% and 24%, respectively) while higher MW compounds were present almost totally in the particulate fraction. The results show that 30%–60% of each PAH by mass were found on particles smaller than 0.43 μm and more than 70% on particles with diameter less than 2.1 μm. In addition, the relationship between the particle/gas partition coefficient (Kp) and the sub-cooled liquid vapor pressure (p°L) was also determined to describe the gas-particle partitioning of those PAH compounds in a tropical atmosphere.
This paper describes a method for the routine determination of 13 typical types of 3–5 ring polycyclic aromatic hydrocarbons (PAHs), occurring in airborne particulates, using gas-liquid chromatography (GLC) with a packed column. The PAHs were completely separated except for the overlap of benzo[k]fluoranthene and benzo[e]pyrene under the proposed GLC conditions. Cyclohexane and a cyclohexane-chloroform (8 + 2) solvent system for column chromatography (CC) were the most effective of the five solvent systems in eliminating interfering components. The average recoveries of the 13 types of PAHs by a CC procedure were in the range 81–103%. An internal standard (1,3,5-triphenylbenzene) method was used to calculate the concentrations of PAHs.
The results of particle size distributions measurements of aliphatic hydrocarbons and Pb-210 in aerosols in the upwelling zone off the Peruvian coast are reported. The data were taken as part of the Sea/Air Exchange Program (Searex) using cascade impactor samples on ships cruising 10-100 km off the coast. The samplers were situated on masts on the bow of the ship, which was steered into the wind, with samples taken only when the wind speeds exceeded 5 m/sec. The dominant aliphatic hydrocarbon fraction was n-alkanes above C20, and n-alkane concentrations were calculated as a function of the carbon number. Increasing Pb-210 concentrations were observed with decreasing particle size, a similar situation to that of the n-alkanes. It is suggested that the particle size distribution characteristics are due to fossil fuel combustion and gas-particle partitioning of the n-alkanes.
Atmospheric tricresyl phosphate (TCP) isomers in Kurose river basin were determined. The concentrations of o-TCP and m-TCP were 0.13 and 0.09ngm−3, respectively, while p-TCP was scarcely detected. Exhaust gases from motorcycles and automobiles were main sources for TCP isomers in the atmosphere. Exhaust gas from incinerator also contributes to atmospheric concentration of TCP isomers. Most of the TCP isomers could be estimated to be sorbed to particles, due to their low vapor pressures. The concentrations of TCP isomers were relatively high in soils collected from an open storage yard of waste PVC and near the highway and greenhouse of agricultural film. On the other hand, the concentrations were negligibly small in soil collected from the forest except for the silt-clay fraction in the soil. Dry deposition fluxes of o-TCP and m-TCP from the atmosphere was 0.2 and 0.04μgm−2d−1, respectively. Wet deposition flux of TCP isomers during one rainfall exceeded occasionally the dry deposition flux for two weeks. TCP isomers accumulated in soil were discharged into river by precipitation event. Their concentrations increased with an increase in river flow, characteristic of a non-point source of TCP isomers.
The environmental importance of atmospheric polycyclic aromatic hydrocarbons (PAH) is briefly discussed. A sampling regime, using filters and Tenax TA adsorbent, is outlined which enables the collection of 18 PAH in air, from both the particulate and gaseous phases. An extraction and clean up process is described, which prepares the sample for reversed phase high performance liquid chromatography (HPLC) by transferring the analyte to acetonitrile. Tests on the overall methodology indicate that the procedure provides a sensitive and accurate method for assessing levels of atmospheric PAH. An examination of the differing sampling efficiency between impaction and filtration was undertaken, which indicated the effect of sampling duration and temperature on sample integrity. Evidence of the impact of other gaseous pollutants on measured PAH concentrations was highlighted by stepwise multiple regression.
A normal phase HPLC methodology using a semi-preparative polyaminocyano column in conjunction with a selection of short-term genotoxicity assays has been developed for bioassay-directed fractionation studies of complex environmental mixtures. To illustrate the effectiveness of this methodology, an organic extract prepared from respirable air particulate samples collected in Hamilton, Canada was separated into a non-polar aromatic fraction and a polar aromatic fraction using a combination of alumina and Sephadex LH20 chromatography. These fractions were evaluated for their genotoxic potential using the Salmonella/microsome (Ames) assay with six different strains of Salmonella.The non-polar aromatic fraction was analyzed by normal phase HPLC and the eluent was collected in one-minute subfractions; these subtractions were bioassayed in three different Salmonella strains (YG1021 -S9, YG1024 -S9 and YG1029 +S9) to afford three different mutation profiles of this sample. Some subfractions which exhibited high mutagenic responses were subjected to further chemical analyses using GC/MS in order to identify those compounds responsible for the genotoxic responses. The nitroarene compounds 2-nitrofluoranthene, 1-nitropyrene and 2-nitropyrene and higher molecular weight polycyclic aromatic hydrocarbons such as benzo[a]pyrene and indeno[l,2,3-cd]pyrene were identified and quantified in some of the biologically active subfractions. The normal phase gradient conditions afforded very reproducible retention times for a series of polycyclic aromatic standards with a broad range of compound polarities. In addition, polycyclic aromatic hydrocarbons (PAH) were observed to elute from the normal phase HPLC column in a series of peaks; successive peaks contained PAH of increasing molecular weight while any individual peak was shown to contain PAH of the same molecular weight.
An improved method for anlaysis of fog oil samples of both aerosol and vapor from field dispersion experiments is described. The intent of this method is to maintain the accuracy and sensitivity of earlier procedures while reducing the analysis and the time required for manual of the samples before analysis. In this method fog-oil is vaporized from a sample using heat, then the hot vapor is analyzed by gas chromatography. A non-polar packed column, which can tolerate a wide range in sample mass loadings, is used for separation of the fog-oil chemical constituents. A flame ionization detector is used to determine the total sample mass. A sensitivity of 0.03 mg has been achieved, and samples up to 20 mg can be analyzed easily. Chromatograms produced using this method give a qualitative molecular weight distribution of the oil. Fog oil smoke is produced by vaporizing the liquid oil in the engine manifold of a thermal smoke generator. Upon mixing into the atmosphere, the vapor forms small aerosol droplets. Glass fiber filters are used for sampling the aerosol fraction of the smoke. Stainless steel tubes filled with Tenax-GC are used for sampling the vapor fraction of the oil. Keywords: Screening smoke; Obscuring smoke; Air pollution.
Urban aerosols were fractionated according to size by an eight-stage low pressure impactor with size resolution down to 0.05 μm diameter. Each stage of the impactor, containing picogram amounts of benzo(a)pyrene (BaP) and other polycyclic aromatic hydrocarbons (PAH) was ultrasonically extracted with benzene. After reduction to appropriate volumes, the extracts were spotted on a TLC plate and developed. The BaP spots were quantitated in situ by finely focusing the TLC plate on the fluorescence excitation beam and measuring the resulting emission while scanning the plate. The regression lines passing thru the origins exhibited linear regression coefficients (R ) between 0.9985 and 0.9996 for three-point BaP calibration data in the 100-1000 picogram range. The relative standard deviations varied between 3.4 and 12.9%, depending on the amount of BaP present. The detection limit for BaP is 5 picogram. The method allows the determination of typical atmospheric Bap size distributions with as little as 1.5 m of sampled air.
The reactivity of PAH substances in urban atmosphere and its influence on the partitioning models between gaseious and particulate phases for semi-volatile PAHs were investigated in this study. A new sampling experiment for gaseous and particulate PAHs during day, night and whole day (24 hours) time periods was conducted at a monitoring station in downtown Taipei in 1991. The reactivity of PAH substances was determined by the characteristic ratio, reactive PAH/non-reactive PAH and the order of reactivity are as follows, Benzo(a)anthracene > Phenathrene + Anthracene > Acenaphthene > Chrysene > Pyrene > Naphthalene > Floranthene > Flourene. On the other hand, the partitioning models for day, night, and whole day for semi-volatile PAHs, Fluoranthene, Pyrene, Chrysene, and Benzo(a)anthracene, were evaluated. It is indicated that higher coefficients of determination (r{sup 2}) of the regression analysis between the partitioning term and inverse of temperature were obtained for day or night models compared to whole day model for Pyrene and Benzo(a)anthracene particularly for Benzo(a)anthracene, which is the most reactive substance investigated in this study. In contrast, no significant difference between model for day or night and whole day was found for Fluoranthene. Thus, the performance of partitioning models for semi-volatile PAHs in atmosphere is influenced by the reactivity of PAHs. The influence is more profound for reactive PAHs. It is shown that general model developed from continuous 24 hours sampling may be reasonable for less reactive PAHs, but separate models for day and night models will be needed for reactive PAHs. 28 refs., 5 figs., 4 tabs.
Particle‐bound composition and size distributions of organic carbon (OC) , elemental carbon (EC) and polycyclic aromatic hydrocarbons (PAHs) were measured by the PS‐1 sampler, NRI (Noll Rotary Impactor) and MOUDIs (Micro‐orifice Uniform Deposit Impactor) in the ambient air of the traffic intersection and rural site in Ping Tung area of Southern Taiwan from September 1994 to December 1995. Elemental analyzer was used to analyze the carbon composition of aerosol samples. Twenty one individual PAHs were analyzed primarily by a gas chromatography/mass spectrometer (GC/MS) . In the ambient air of Ping Tung area, the aerosol carbons accounted for 18.7%‐25.5% of the total suspended particulate (TSP) mass loading. EC and OC comprised about 12% and 10% of the TSP mass, respectively. The concentration ratios for TC/EC ranged between 1.4 and 2.6 and averaged 2.0 during the sampling periods. More than 80% of particle‐bound composition of 12 potential carcinogenic‐PAHB, namely CYC, BaA, CHR, BbF, BkF, BeP, BaP, PER, IND, DBA, BbC, and BghiP, were existed in the particle size less than 2.5 μm. The size distribution for particle‐bound composition of OC, and EC are all bimodal. The bi‐peaks were all localized at 0.18–0.32 and 1.8–3.2 ranges, respectively. However, the particle size distribution of particle‐bound total‐PAH compositon was found to have trimodal size distribution; the major peaks were localized at 0.05–0.1 μm, 0.18–0.32 μm and 1.8–3.2 μm, respectively, which also mostly belonged to the fine particle mode (Dp < 2.5 μm) . The major peaks for particle‐bound composition of OC, EC and total‐PAHs particle size distribution all located at the fine particle mode indicate not only the gas‐to‐particle condensation in the fine particle mode after those are emitted to the atmosphere but also reveal some important information related to health hazards in the ambient air of traffic intersection. In the ambient air of traffic intersection, the cumulative fraction of carcinogenic‐PAHs and TSP in the particle size less than 1 μm were 71.5% and 15.5%, respectively, while those values in the particle size less than 2.5 μm were 79.5% and 18.6%, respectively. More than 96% of carainogenic‐PAHs were existed in the particle size less than 10 μm. However, more than 68% of TSP were existed in the particle size larger than 10 μm.
Polycyclic aromatic hydrocarbon (PAH) samples in the ambient air of rural, urban and traffic‐intersection sites have been collected by PS‐1 samplers, NRI (Noll Rotary Impactor) and MOUDIs (Micro‐orifice Uniform Deposit Impactors) from July, 1993 to January, 1995 in southern Taiwan. Twenty one individual PAHs were analyzed primarily by a gas chromatograph/mass spectrometer (GC/MS). The mean total‐PAH concentrations (gas+particle phases) in the ambient air of traffic‐intersection was approximately 5.6 and 14.1 times higher than those mean values for the urban and rural atmosphere, respectively. It is reveals that the high density of vehicle exhaust raises the PAH concentrations in the urban ambient air. In the ambient air of the traffic‐intersection, most of the G/R (ground/roof) ratios for individual PAHs concentration in gas phase were higher than 1.0, except BaA, BeP, PER and BghiP. This result shows that PAHs concentration in gas phase was related to the automobile exhaust. Upon entering the ambient air of the traffic‐intersection, these PAHs was condensed, cooled and dispersed at higher elevation. In the traffic intersection, the PAHs are predominantly absorbed on particles with aerodynamic diameters less than 2.5 μm (the fine particles), a fact which strongly relates to the risk potential. The results also show that the total PAHs in the ambient air of a traffic intersection originated mainly from mobile exhaust and the phenomena of condensation process for the young aerosols. However, in the traffic‐intersection, higher fraction of total‐particle mass in the coarse particle mode is primarily the road dust which is due to traveling vehicles.
Atmospheric PAH (polycyclic aromatic hydrocarbon) and total‐particle mass size distributions in the ambient air of a bus station, an urban and a rural site were measured with two MOUDIs (Micro‐orifice Uniform Deposit Impactors) and a NRI (Noll Rotary Impactor) from April to September 1996, in southern Taiwan. The overall particle size range was covered from 0.056 to 100 urn and separated into the twelve size ranges: 0.056 0.10, 0.10 0.18, 0.18 0.32, 0.32 0.56, 0.56 1.0, 1.0 1.8, 1.8 3.2, 3.2 5.6, 5.6 10, 10 24.7, 24.7 36.5 and 36.5 100 μm. Twenty one individual PAHs were analyzed primarily by using a gas chromatograph/mass spectrometer (GC/MS). In the ambient air of the bus station, the particle size distribution of total PAHs had a bimodal size distribution; the bi‐peaks were localized at 0.18 0.32 μm (mode I) and 0.56 1.0 μm (mode II), which all belonged to the fine particle mode (Dp < 2.5 μm). For the bus station, the mode I results from primary emissions of PAH from vehicular emissions, and the mode II in the PAH size distributions is consistent with the growth of mode I particles emitted from vehicles and other combustion sources by condensation of secondary reaction products on their surfaces. At the urban and rural sites, the particle size distributions of total PAHs were also found to have bimodal size distribution; the bi‐peaks for the urban site were localized at 0.56 1.0 and 3.2 5.6 μm, while those at the rural site were localized at 0.56 1.0 and 1.8 3.2 μm. It is believed that part of the PAH burden emitted from the mobile exhaust is condensed as or adsorbed on particulates, which then shift, react or decay in the atmosphere during the transport process. This may explain the decrease in the PAH mass fraction in the particle phase of samples from well‐mixed urban and rural air. In the ambient air of the bus station, the cumulative fraction of total PAHs in the particle size range below 1, 2.5 and 10 um, in sequence, were 60.1%, 70.0% and 89.9%, respectively. For the urban site, the cumulative fraction of total PAHs in the particle size range below 1, 2.5 and 10 μm, in sequence, were 46.4%, 54.5% and 83.2%, respectively, while those values at the rural site, in sequence, were 35.3%, 48.5% and 76.1%, respectively. These results revealed that the ambient air of the bus station had more young‐aerosol mass emitted from the mobile exhaust and primarily existed in the submicron particles, which were strongly related to a potential health risk. In the ambient air of the bus station, urban and rural sites, the MMD of total PAHs were 0.48,0.89 and 1.05 um, respectively, while those of total particle mass were 4.32, 3.12 and 2.86 urn, separately. This result reveals that a greater fraction of PAH mass exists in the fine aerosol (Dp < 1.0 um).
Simultaneous air samples were taken in Chicago and over southern Lake Michigan as part of the AEOLOS Project (Atmospheric Exchange Over Lakes and Oceans). Gas and particle phase concentrations of polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and total suspended particles (TSP) were measured over 12 h periods during July, 1994, and January, 1995. Partitioning of PCBs and PAHs between gas and particle phases was well correlated with the subcooled liquid vapor pressure (p°L) for individual samples, but the relationship differed among samples. For all but a few of the samples the slopes of the log Kp vs log p°L lines were statistically greater than −1. Other investigators who have found similar results have concluded that the PCBs/PAHs were not at equilibrium; however, other factors indicate that the PCBs and PAHs in the Chicago/Lake Michigan atmosphere are at equilibrium. Slopes of the regressions of log Kp vs log p°L from samples of continental background origin, and therefore assumed to have had sufficient atmospheric residence times to reach equilibrium, are among the shallowest measured (−0.70 to −0.53 and −0.16 to −0.56 for PAHs and PCBs, respectively). One pair of samples where the air mass is believed to have been sampled twice, once in the urban area and again 3.4 h downwind, shows no difference in partitioning. PCBs and PAHs measured in Chicago and over Lake Michigan were apparently at equilibrium between the gas and particle phases. A slope of −1 in the regression of log Kp vs log p°L is not necessary to describe equilibrium partitioning. Differences in particulate matter may be responsible for the shallow slopes observed.
Aerosol samples corresponding to well-defined cold/warm seasons in the atmosphere of Barcelona have been collected and size-fractionated during stable atmospheric conditions. A predominant hydrocarbon pattern derived from gasoline and diesel vehicular traffic emissions has been identified in most particle fractions. In quantitative terms, these hydrocarbons exhibit a predominant occurrence in the submicron fractions, particularly the <0.5-mum fraction, which is likely characteristic of early aging stages after gas-phase emission of combustion residues to the atmosphere. This predominant occurrence contrasts with the bimodal log-normal distribution of particles found in the city. The seasonal fluctuations of these hydrocarbons reflect a strong decrease in the warm period. The changes in fine particulate (<1.5 mum) content of n-alkanes and polycyclic aromatic hydrocarbons (PAH) show that these fluctuations are due to atmospheric dilution and, in the case of PAH, photochemical degradation. Another seasonal effect is related to the hydrocarbon content in the individual particulate fractions, showing a preferential association of n-alkanes with molecular weight (MW) >254 and PAH with MW >202 for the 0.56-0.96- and <0.5-mum size fractions in the cold and warm periods, respectively. The qualitative and quantitative composition of these hydrocarbon distributions is described, and the observed changes are discussed in terms of particle-size dependency and seasonal effects.
Data are presented on the mutagenicity of an organic extract of a composite sample of urban air particulates and of thirty PAH compounds in such samples, including four quinone derivatives, isolated quantitatively by thin-layer chromatography and identified by fluorescence or other spectral techniques. Mutagenic activity was determined by the Ames assay, using histidine auxotrophs of Salmonella typhimurium strains TA98, TA100, TA1537 and TA1538. All compounds were dissolved in dimethyl sulfoxide (DMSO) which was the least toxic of eight organic solvents tested.The mutagenic activity of a benzene extract of suspended particulates from the air of Hamilton, Ontario was significantly greater with strain TA98 than with strain TA100, suggesting the presence of more frame-shift acting mutagens. The mutagenic response of this extract was similar with and without S-9 activation.Mutagenic tests on the 30 PAH compounds indicated that only the benzo(a)pyrene quinones were direct acting mutagens. All of the chemical compounds were tested with and without S-9 activation. The following PAH showed unequivocal mutagenic activity, with S-9 activation: benz(a)anthracene, benzo-(a)pyrene, benzo(ghi)perylene, benzo(rst)pentaphene, benzophenanthrene, chrysene, 1, 2, 3, 4-dibenzanthracene, 2, 3, 6, 7-dibenzanthracene, and 3-methyl cholanthrene. The quinones of 1, 6-; 3, 6-; and 6, 12-benzo(a)pyrenes showed weak mutagenic activity but 3, 6-benzo(a)pyrene elicited also a photodynamic response.
The saturated or equilibrium vapour concentrations of the following inorganic substances and polycyclic aromatic hydrocarbons are reported: SeO2, As4O6, pyrene, B(a)A, B(a)P, B(e)P, B(k)F, B(ghi)P and coronene. The significance of these results with respect to the efficacy of collection of these pollutants on particulate filters and the validity of the previous measurements of collection efficiency are considered in detail. The conclusion is that significant losses may be expected for some of these compounds (As4O6, SeO2, pyrene and B(a)A), that the efficacy of collection is subject to considerable question for some others [B(a)P, B(e)P and B(k)F] although losses may be minimized by adsorption effects, and that for others still [B(ghi)P, coronene] losses should be insignificant.
The separation and resolution of a number of polynuclear aromatic hydrocarbons (PAH's) were studied in samples of particulate matter collected from the urban atmosphere by methods involving thin-layer chromatography (TLC) and fluorescence spectroscopy, gas chromatography and mass spectroscopy (GC/MS). The concentration levels of 10 PAH's in particulate air samples from the Ontario cities of Toronto, Hamilton, Sarnia, and Sudbury were determined quantitatively by TLC-fluorescence methods over 3-month periods from April 1975 to March 1976. Among these cities, significant differences in concentrations, related to the predominant emission sources, were found for benzo(a)pyrene, benzo(e)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(ghi)perylene, naphtho(1,2,3,4-def)chrysene, and dibenzo(b,def)chrysene.
High-volume air samplers were used to collect samples of airborne particulate matter on an intermittent schedule at 39 locations throughout Los Angeles County for a full year. Composites were extracted and analyzed for 14 polycyclic aromatic hydrocarbons (PAH). Major PAH show high seasonal correlations (negative) with median early morning atmospheric inversion heights. PAH are highest during the November--January quarter but ranges for different PAH vary by factors 4 to 10 during the year. Comparison of relative PAH concentration patterns for different areas suggest that PAH in the better ventilated coastal areas arise primarily from automobiles, while in the areas farthest inland additional smaller amounts of PAH arise from nonautomobile sources. Benzo(a)pyrene averaged 0.46 ng/m³, but no composite concentration was higher than 2.0 ng/m³.
An examination was made of the dependency of polynuclear aromatic hydrocarbon (PAH) content on the particle size distribution of atmospheric suspended particulate matter. Ambient aerosols were collected in specific time periods during 1972 and 1973 using size-fractionating cascade impactors (Anderson ''Hi-Vol'' samplers) at five sites in Toronto, Ont. Collected particulate matter was extracted with benzene in a Soxhlet apparatus. Eight PAH's and two oxygenated arenes were separated by thin-layer chromatography and identified and analyzed by absorption and fluorescence spectrophotometry. The efficiency and accuracy of the procedures involved were studied. The size distribution of PAH-containing particulates followed approximately a log-normal relationship for suburban and rural sampling sites with the majority of PAH content associated with particles below 3.0 ..mu..m diameter. Significant variations were discovered in PAH content between downtown-urban, urban, suburban, and rural areas. PAH concentration in submicron particles increased during the winter months.
Little is known of the fate of arenes in the atmosphere. To gain some knowledge of behavior of these arenes, benzo[a]-pyrene in solid phase was studied under various treatments. Infrared analyses were used to describe the changes which occurred under treatment (900 to 700 cm. -1 out-of-plane C - H bending vibration). Other isomers of B(a)P, perylene and B(e)P, and a few other poly nuclear aromatic hydrocarbons did not show any changes in infrared curves under the same treatments. Hypothetical structural analyses also were postulated regarding the soot and polynuclear aromatic hydrocarbons, as polynuclear aromatic hydrocarbons do not exist when there is no soot.
Polycyclic aromatic hydrocarbons (PAHs) having the same molecular weight and possessing similar structures have been difficult to separate quantitatively using standard chromatographic techniques. A thin layer chromatographic procedure involving a preliminary group separation on aluminum oxide followed by resolution of the isomeric arenes on acetylated cellulose has been developed as an aid in the fractionation of three isomeric groups of polycyclic arenes present in ambient particulate matter. Five pentacyclic and seven hexacyclic arenes have been quantitatively isolated using this procedure. Two dimensional thin layer chromatography on a composite plate of aluminum oxide:40% acetylated cellulose was also used for identification purposes. Thin layer chromatography coupled with fluorescence spectrophotometry proved to be an effective analytical technique for the determination of isomeric PAH content in atmospheric aerosols.
A high pressure liquid chromatographic method has been developed and applied to polycyclic aromatic hydrocarbons (PAH) in New York City suspended particulate matter samples. Particulate matter collected on filters was Soxhiet extracted using cyclohexane, and extractable matter was prefractionated by thin layer chromatography. The PAH fraction was concentrated and separated by HPLC with an ODS Zorbax column. About 20 PAH were identified in effluent fractions by uv and fluorescence spectrophotometry. Submicrogram quantities of PAH were quantitated by the peak height method. The detection limit of benzo(a)pyrene is about 10 ng. Good crosschecks were obtained by gas chromatography mass spectrometry (GC MS).