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Showing papers on "Particulates published in 2004"


Journal ArticleDOI
TL;DR: In this paper, the effects of the dust events on the aerosol parameters retrieved over Kanpur (located in the heart of the Indo-Gangetic basin) from ground-based Aerosol Robotic Network (AERONET) measurements are presented.
Abstract: Rajasthan Province, which is covered by the Thar Desert. In this paper, we present the effects of the dust events on the aerosol parameters retrieved over Kanpur (located in heart of the Indo-Gangetic basin) from ground-based Aerosol Robotic Network (AERONET) measurements. The aerosol parameters show strong seasonal variability in this region, with least spectral dependence of aerosol optical depth (AOD) during the premonsoon season, characterized by dust loading. The aerosol optical properties over the IndoGangetic basin are controlled by the diurnal and seasonal cycles of urban pollutants, but the dust storms are so significant that the local cycle is completely overshadowed. A rise in AOD by more than 50% and corresponding decrease in angstrom parameter by 70–90% have been observed after each dust event. The diurnal variations of AOD during the dust events have been found to be controlled by the onset of the dust storms. The changes in the single scattering albedo (SSA) and real n(l) and imaginary k(l) parts of the refractive index indicate that the 27 May 2002 event influences the optical state to be absorbing, whereas for the other four events the aerosols are found to be dominantly scattering in nature. SSA has been found to increase sharply at higher wavelengths (l > 440 nm) during the dust events, whereas n(l) and k(l) increase 2–3 times more at l = 440 nm compared to those at higher wavelengths. The contrasting change in the spectral variations of the optical properties is due to the difference in the nature of the aerosols loading during the events. Aerosol volume concentration at coarse mode is found to increase three times after the dust events, whereas no significant change has been observed in the volume concentration at fine mode. Concentration of the particulate matters less than 10 m m( PM10) is also found to increase by � 150 m gm � 3 after each dust event except on the 27 May 2002 event, when heavy rainfall after the dust storm washed out the suspended particulate matters from the atmosphere, and the ground level PM10 concentration was not influenced by the advected dust particles on that day. Aerosol index values in successive Total Ozone Mapping Spectrometer (TOMS) images over the region support the characterization of the aerosols in this region in terms of their optical properties, which are being transported over the Indo-Gangetic basin from the western Thar Desert and the Gulf regions depending upon the size of the particles, shown by the air mass trajectories. INDEX TERMS: 0305 Atmospheric Composition and Structure: Aerosols and particles (0345, 4801); 0345 Atmospheric Composition and Structure: Pollution—urban and regional (0305); 1640 Global Change: Remote sensing; 3309 Meteorology and Atmospheric Dynamics: Climatology (1620); 3360 Meteorology and Atmospheric Dynamics: Remote sensing; KEYWORDS: aerosol, dust, India

389 citations


Journal ArticleDOI
TL;DR: In this paper, the variability of the organic particulate composition and size distribution as a function of location and photochemical activity with a particular emphasis on the urban and rural areas was studied.

375 citations


Journal ArticleDOI
TL;DR: Among a frail population, individuals diagnosed with myocardial infarction or diabetes were at greatest risk of death associated with high concentrations of PM10, suggesting that their susceptibility may derive from prior vascular damage to the heart.
Abstract: Background:Populations susceptible to the effects of particulate matter have begun to be characterized, but the independent contributions of specific factors have not been explored.Methods:We used a case-crossover study to examine PM10-associated mortality risk during 1988–1991 among 65,180 elderly

337 citations


Journal ArticleDOI
TL;DR: In this article, the CHIMERE chemistry transport model (Atmos. Environ. 35 (2001) 6277) has been improved to account for particle transport, formation, deposition at the European scale.

331 citations


Journal ArticleDOI
TL;DR: The ACE-Asia aerosols are composed not only of desert dust but also of soil dust, smoke from biomass and refuse burning, and emissions from fossil fuel use in urban areas as discussed by the authors.
Abstract: [1] The organic compound tracers of atmospheric particulate matter, as well as organic carbon (OC) and elemental carbon (EC), have been characterized for samples acquired during the Asian Pacific Regional Aerosol Characterization Experiment (ACE-Asia) from Gosan, Jeju Island, Korea, from Sapporo, Japan, and from Chichi-jima Island in the western North Pacific, as well as on the National Oceanic and Atmospheric Administration R/V Ronald H. Brown. Total extracts were analyzed by gas chromatography–mass spectrometry to determine both polar and aliphatic compounds. Total particles, organic matter, and lipid and saccharide compounds were high during the Asian dust episode (early April 2001) compared to levels at other times. The organic matter can be apportioned to seven emission sources and to significant oxidation-producing secondary products during long-range transport. Terrestrial natural background compounds are vascular plant wax lipids derived from direct emission and as part of desert sand dust. Fossil fuel utilization is obvious and derives from petroleum product and coal combustion emissions. Saccharides are a major polar (water-soluble) carbonaceous fraction derived from soil resuspension (agricultural activities). Biomass-burning smoke is evident in all samples and seasons. It contributes up to 13% of the total compound mass as water-soluble constituents. Burning of refuse is another source of organic particles. Varying levels of marine-derived lipids are superimposed during aerosol transport over the ocean. Secondary oxidation products increase with increasing transport distance and time. The ACE-Asia aerosols are composed not only of desert dust but also of soil dust, smoke from biomass and refuse burning, and emissions from fossil fuel use in urban areas.

283 citations


Journal Article
TL;DR: The organic compound tracers of atmospheric particulate matter, as well as organic carbon (OC) and elemental carbon (EC), have been characterized for samples acquired during the Asian Pacific Regional Aerosol Characterization Experiment (ACE-Asia) from Gosan, Jeju Island, Korea, from Sapporo, Japan, and from Chichi-jima Island in the western North Pacific, as discussed by the authors.
Abstract: The organic compound tracers of atmospheric particulate matter, as well as organic carbon (OC) and elemental carbon (EC), have been characterized for samples acquired during the Asian Pacific Regional Aerosol Characterization Experiment (ACE-Asia) from Gosan, Jeju Island, Korea, from Sapporo, Japan, and from Chichi-jima Island in the western North Pacific, as well as on the National Oceanic and Atmospheric Administration R/V Ronald H. Brown. Total extracts were analyzed by gas chromatography-mass spectrometry to determine both polar and aliphatic compounds. Total particles, organic matter, and lipid and saccharide compounds were high during the Asian dust episode (early April 2001) compared to levels at other times. The organic matter can be apportioned to seven emission sources and to significant oxidation-producing secondary products during long-range transport. Terrestrial natural background compounds are vascular plant wax lipids derived from direct emission and as part of desert sand dust. Fossil fuel utilization is obvious and derives from petroleum product and coal combustion emissions. Saccharides are a major polar (water-soluble) carbonaceous fraction derived from soil resuspension (agricultural activities). Biomass-burning smoke is evident in all samples and seasons. It contributes up to 13% of the total compound mass as water-soluble constituents. Burning of refuse is another source of organic particles. Varying levels of marine-derived lipids are superimposed during aerosol transport over the ocean. Secondary oxidation products increase with increasing transport distance and time. The ACE-Asia aerosols are composed not only of desert dust but also of soil dust, smoke from biomass and refuse burning, and emissions from fossil fuel use in urban areas.

262 citations


Journal ArticleDOI
TL;DR: In this paper, it was found that low molecular weight polar organic acids account for a significant fraction of the water soluble organic carbon (WSOC) in biomass burning aerosols (C2-C6 dicarboxylic acids reached up to 3.7% and one-ring aromatic acids reached 2% of fine fraction WSOC during burning period).
Abstract: . Particles from biomass burning and regional haze were sampled in Rondonia, Brazil, during dry, transition and wet periods from September to November 2002, as part of the LBA-SMOCC (Large-Scale Biosphere-Atmosphere Experiment in Amazonia – Smoke, Aerosols, Clouds, Rainfall, and Climate) field campaign. Water soluble organic and inorganic compounds in bulk (High Volume and Stacked Filter Unit sampler) and size-resolved (Micro Orifice Uniform Deposit Impactor – MOUDI) smoke samples were determined by ion chromatography. It was found that low molecular weight polar organic acids account for a significant fraction of the water soluble organic carbon (WSOC) in biomass burning aerosols (C2-C6 dicarboxylic acids reached up to 3.7% and one-ring aromatic acids reached up to 2% of fine fraction WSOC during burning period). Short dicarboxylic (C2-C6) acids are dominated by oxalic acid followed by malonic and succinic acids. The largest ionic species is ammonium sulfate (60–70% of ionic mass). It was found that most of the ionic mass is concentrated in submicrometer-sized particles. Based on the size distribution and correlations with K+, a known biomass burning tracer, it is suggested that many of the organic acids are directly emitted by vegetation fires. Concentrations of dicarboxylic acids in the front and back filters of high volume sampler were determined. Based on these measurements, it was concluded that in the neutral or slightly basic smoke particles typical of this region, dicarboxylic acids are mostly confined to the particulate phase. Finally, it is shown that the distribution of water soluble species shifts to larger aerosols sizes as the aerosol population ages and mixes with other aerosol types in the atmosphere.

204 citations


Journal ArticleDOI
TL;DR: In this paper, the authors conducted systematic measurements of the concentration and size distribution of ultrafine particles in the vicinity of Interstate 405 (mostly gasoline traffic) and Interstate 710 (large proportion of heavy-duty diesel traffic) in Los Angeles during the summer of 2001.
Abstract: Ultrafine particles (diameter <0.1 μm) have been suggested as a possible causative agent for the observed increases in mortality and morbidity with increases in particulate matter (PM) concentration. Zhu et al. conducted systematic measurements of the concentration and size distribution of ultrafine particles in the vicinity of Interstate 405 (mostly gasoline traffic) and Interstate 710 (large proportion of heavy-duty diesel traffic) in Los Angeles during the summer of 2001. The present study compares these measurements with those made at the same locations in the winter of 2001–2002. Particle number concentration and size distribution in the size range from 6 to 220 nm were measured by a condensation particle counter (CPC) and a scanning mobility particle sizer (SMPS). Measurements were taken at five distances downwind from the freeway. At each sampling location, concentrations of carbon monoxide (CO) and black carbon (BC) were also measured by a Dasibi CO monitor and an aethalometer, respectively. Avera...

186 citations


Journal ArticleDOI
TL;DR: The PM10 levels recorded at EMEP regional background stations between March 2001 and March 2002 are very close to the annual limit value proposed for 2010 by the EU Air Quality Directive 1999/30/CE.

179 citations


Journal ArticleDOI
TL;DR: It is indicated that the temperature-resolved carbon fraction data can be utilized to enhance source apportionment, especially with respect to the separation of diesel emissions from gasoline vehicle sources.
Abstract: Integrated ambient particulate matter < or =2.5 microm in aerodynamic diameter (PM2.5) samples were collected at a centrally located urban monitoring site in Washington, DC, on Wednesdays and Saturdays using Interagency Monitoring of Protected Visual Environments samplers. Particulate carbon was analyzed using the thermal optical reflectance method that divides carbon into four organic carbon fractions, pyrolyzed organic carbon, and three elemental carbon fractions. A total of 35 variables measured in 718 samples collected between August 1988 and December 1997 were analyzed. The data were analyzed using Positive Matrix Factorization and 10 sources were identified: sulfate (SO4(2-))-rich secondary aerosol I (43%), gasoline vehicle (21%), SO4(2-)-rich secondary aerosol II (11%), nitrate-rich secondary aerosol (9%), SO4(2-)-rich secondary aerosol III (6%), incinerator (4%), aged sea salt (2%), airborne soil (2%), diesel emissions (2%), and oil combustion (2%). In contrast to a previous study that included only total organic carbon and elemental carbon fractions, motor vehicles were separated into fractions identified as gasoline vehicle and diesel emissions containing carbon fractions whose abundances were different between the two sources. This study indicates that the temperature-resolved carbon fraction data can be utilized to enhance source apportionment, especially with respect to the separation of diesel emissions from gasoline vehicle sources. Conditional probability functions using surface wind data and deduced source contributions aid in the identifications of local sources.

171 citations


Journal ArticleDOI
TL;DR: Polar organic compounds in aerosol particulate matter from Malaysia are converted to their trimethylsilyl derivatives and analyzed by gas chromatography-mass spectrometry in order to better assess the contribution of the biomass burning component during the haze episodes.

Journal ArticleDOI
TL;DR: Investigation of the interaction between daily particulate air pollution and daily mean temperature in Cook County, Illinois and Allegheny County, Pennsylvania, using data for the period 1987-1994 suggests that in community particulates air pollution mortality time series studies the possibility of an interaction betweendaily particulateAir pollution anddaily mean temperature should be considered.

Journal ArticleDOI
TL;DR: In this paper, in vitro dissolution experiments were conducted in seawater in order to quantify the partitioning between dissolved and particulate phases of iron associated to Saharan dust and urban particles, and the results showed that the percentage of iron released was very low (0.05 to 2.2%) depending on the particulate load, the aerosol source and the contact time.
Abstract: [1] In vitro dissolution experiments were conducted in seawater in order to quantify the partitioning between dissolved and particulate phases of iron associated to Saharan dust and urban particles. The percentage of iron released was very low (0.05 to 2.2%) depending on the particulate load, the aerosol source and the contact time. This percentage decreased with the amount of particles introduced following a power law, indicating that the process could be modeled. Indeed, these dissolution processes were a function of the lability of iron in relation to the particle source, the particle size and adsorption processes. According to these experiments, the dissolved iron induced in a 10 m mixed layer by Saharan events of various magnitudes ranges from 0.07 to 1 nM. Since these concentrations are in agreement with the natural iron requirements for the phytoplankton, such inputs can profoundly influence the primary production, especially in oligotrophic conditions.

Journal ArticleDOI
TL;DR: In this paper, two Aerodyne aerosol mass spectrometers (AMSs) were deployed at Trinidad Head on the north Californian coast during the National Oceanographic and Atmospheric Administration Intercontinental Transport and Chemical Transformation 2002 (ITCT 2K2) experiment, to study the physiochemical properties of submicron aerosol particles within the Pacific marine boundary layer.
Abstract: [1] Two Aerodyne aerosol mass spectrometers (AMSs) were deployed at Trinidad Head on the north Californian coast during the National Oceanographic and Atmospheric Administration Intercontinental Transport and Chemical Transformation 2002 (ITCT 2K2) experiment, to study the physiochemical properties of submicron aerosol particles within the Pacific marine boundary layer. One AMS was modified to allow the study of sea salt-based particles, while the other used a temperature cycling system on its inlet. The reported loadings increased by a factor of 2 when the temperature approached the dew point, which is due to the inlet performance and has implications for other AMS experiments and applications. The processed data were compared with those of a particle into liquid sampler-ion chromatograph and showed that the ammonium, sulfate and organic fractions of the particles were consistently found within a single, normally acidic, accumulation mode at around 300 - 400 nm. However, when influenced by land-based sources, vehicle emissions and increased ammonium loadings were seen. The concentrations of nitrate in the accumulation mode were low, but it was also found within sea salt particles in the coarse mode and can be linked to the displacement of chloride. The organic fraction showed a high degree of chemical ageing and evidence of nitrogen-bearing organics was also observed. The particulate organic data were compared to the volatile organic carbon data derived from an in-situ gas chromatograph-mass spectrometer-flame ionization detector and relationships were found between the gas and particle phase chemicals in both the overall concentrations and the levels of oxidation.

Journal ArticleDOI
TL;DR: This study provides the first extensive characterization of endotoxin concentration across a large metropolitan area in relation to PM10 and other pollutant monitoring, and supports the need for studies of the role of endot toxin in childhood asthma in urban settings.
Abstract: Concentrations of endotoxin in urban air pollution have not previously been extensively characterized. We measured 24-hr levels of PM10 (particulate matter < 10 microm in aerodynamic diameter) and ...

Journal ArticleDOI
TL;DR: The increased focus on potential adverse health effects associated with exposure to ambient particulate matter (PM) motivates a careful characterization of particle emissions from different sources as mentioned in this paper, which can be found in this paper.
Abstract: The increased focus on potential adverse health effects associated with exposure to ambient particulate matter (PM) motivates a careful characterization of particle emissions from different sources ...

Patent
03 Mar 2004
TL;DR: In this paper, an exhaust passage (2) of a diesel engine (1) is provided with a filter (41) for trapping particulate matter and regeneration of the filter is divided into first to third phases.
Abstract: An exhaust passage (2) of a diesel engine (1) is provided with a filter (41) for trapping particulate matter. Regeneration of the filter (41) is divided into first to third phases. In the first phase the filter temperature is raised to the combustion temperature of the particulate matter in a short period of time through control of the exhaust gas temperature. In the second phase, the oxygen concentration of the exhaust gas is held at a predetermined low level while the filter temperature is maintained so as to prevent excessive combustion of particulate matter. In the third phase, wherein the amount of trapped particulate matter has been reduced, the oxygen concentration of the exhaust gas is held at a predetermined high level while the filter temperature is maintained so as to complete the combustion of the trapped particulate matter.

Journal ArticleDOI
TL;DR: Detailed analysis of particle-phase organic compounds revealed very low concentrations of primary anthropogenic emissions and relatively high levels of organic di-, tri-, and tetracarboxylic acids thought to be indicators of secondary organic aerosols.
Abstract: The trends in secondary organic aerosol at a remote location are studied using atmospheric fine particulate matter samples collected at Seney National Wildlife Refuge (NWR) in northern Michigan. Detailed analysis of particle-phase organic compounds revealed very low concentrations of primary anthropogenic emissions and relatively high levels of organic di-, tri-, and tetracarboxylic acids thought to be indicators of secondary organic aerosols. Seasonal changes in these organic compounds were tracked by analyzing composites of monthly average samples. The concentration of aromatic and aliphatic dicarboxylic acids peak in July and taper off in the fall, which coincides with fine particle organic carbon concentration. In contrast, a chemical mass balance model used to quantify primary sources of particulate matter shows higher contributions from primary emissions in the winter. Complementing the monthly average concentrations, event-based composites of high volume samples were used to track the different species of secondary organic aerosol at the Seney NWR location. The distribution of aliphatic diacids and the aromatic di- and triacids varied with different atmospheric conditions, which suggests different precursor gases for these secondary organic aerosol components. The aliphatic diacid concentrations track with ambient concentrations of particle-phase pinonic acid. In addition, back-trajectories for the eight event-based composites are compared to the organic acid distributions and are linked to the distribution of organic acids present in the composites.

Patent
16 Sep 2004
TL;DR: In this paper, a diesel particulate filter (10) which traps particulate matter contained in the exhaust gas of a diesel engine was regenerated through fuel injection control of a fuel injector.
Abstract: To regenerate a diesel particulate filter (10) which traps particulate matter contained in the exhaust gas of a diesel engine (20), a controller (16) raises the temperature of the exhaust gas through fuel injection control of a fuel injector (23), and thus burns the particulate matter trapped in the filter (10). The controller (16) cumulatively calculates the time during which the temperature of the filter (10) exceeds a target temperature as an effective regeneration time. By estimating the amount of particulate matter remaining in the filter (10) on the basis of the effective regeneration time, the controller (16) estimates the amount of remaining particulate matter with a high degree of precision and without consuming energy, whereupon regeneration of the filter (10) through fuel injection control ends.

Journal ArticleDOI
TL;DR: In this paper, a new emission inventory for black carbon, (BC) was developed on the basis of the recent European emission inventory of anthropogenic primary particulate matter (Coordinated European Programme on Particulate Matter Emission Inventories, Projections and Guidance (CEPMEIP).
Abstract: We present a model simulation for the year 1995 accounting for primary particles, which are an important component of fine aerosols over Europe. A new emission inventory for black carbon, (BC) was developed on the basis of the recent European emission inventory of anthropogenic primary particulate matter (Coordinated European Programme on Particulate Matter Emission Inventories, Projections and Guidance (CEPMEIP)). The annual BC emissions of Europe and the former Soviet Union for 1995 are estimated at 0.47 and 0.26 Tg C, respectively, with highest contributions from transport (off-road and on-road) and households. Modeled BC concentrations range from ≤0.05 μtg/m 3 in remote regions to more than 1 μtg/m3 over densely populated areas. The modeled BC concentration is about 25% of the total primary aerosol concentration. The primary aerosol fields were combined with previously calculated secondary aerosol concentrations to obtain an estimate of the total anthropogenic fine aerosol distribution. Modeled BC levels contribute only 4 10% to fine aerosol mass, whereas sulphate and nitrate contribute 25-50 and 5-35%, respectively. Comparison with experimental data revealed that the model underestimates PM2.5 levels, mostly caused, by the underprediction of total carbonaceous material (BC and OC) by a factor of e12. The underestimation can partly be explained by the influence of local emissions, measurement uncertainties, natural sources, and representation of wet deposition. However, the uncertainties associated with the emission inventory for BC (and total PM) may be the most important cause for the discrepancy. In comparison with previous studies, our BC emission estimate is a factor of 2 lower, caused by the choice of more recent emission factors. Therefore a better knowledge of emission factors is urgently needed to. estimate the BC (and PM) emissions reliably. Copyright 2004 by the American Geophysical Union.

Journal ArticleDOI
TL;DR: In this article, the size, morphology and chemical composition of more than 27,000 individual aerosol particles were determined by high-resolution scanning electron microscopy and energy-dispersive X-ray microanalysis.

Journal ArticleDOI
TL;DR: In this article, the authors used the thermal optical reflectance method, which divides carbon into four organic carbon, pyrolyzed organic carbon (OP), and three elemental carbon (EC) fractions.
Abstract: [i] Integrated, 24-hour, ambient PM 2.5 (particulate matter <2.5 μm in aerodynamic diameter) samples were collected at a rural monitoring site in Brigantine, New Jersey, on Wednesdays and Saturdays using Interagency Monitoring of Protected Visual Environments (IMPROVE) samplers. Particulate carbon was analyzed using the thermal optical reflectance method, which divides carbon into four organic carbon (OC), pyrolyzed organic carbon (OP), and three elemental carbon (EC) fractions. A total of 910 samples and 36 variables collected between March 1992 and May 2001 were analyzed using positive matrix factorization, and 11 sources were identified: sulfate-rich secondary aerosol I (48%), gasoline vehicle (13%), aged sea salt (8%), sulfate-rich secondary aerosol II (7%), nitrate-rich secondary aerosol (6%), sulfate-rich secondary aerosol III (5%), sea salt (4%), airborne soil (4%), diesel emission (3%), incinerator (2%), and oil combustion (1%). Temperature-resolved carbon fractions enhanced source separations including three sulfate-rich secondary aerosols and two traffic-related sources that had different abundances of carbon fractions different between sources. Conditional probability functions using surface wind data and deduced source contributions aid in the identification of local sources. Potential source contribution function (PSCF) analysis shows the regional influence of sulfate-rich secondary aerosols. Backward trajectories indicate that the highly elevated airborne soil impacts at the monitoring site were likely caused by either Asian or Sahara dust storms.

Journal ArticleDOI
TL;DR: Comparison of PAH versus EC and active surface area concentrations at different locations suggests that surface PAH concentrations may diminish with particle aging, and indicates that exposure to vehicle-related PAH emissions on Mexico City's roadways may present an important public health risk.
Abstract: Surface properties of aerosols in the Mexico City metropolitan area have been measured in a variety of exposure scenarios related to vehicle emissions in 2002, using continuous, real-time instruments. The objective of these experiments is to describe ambient and occupational particulate polycyclic aromatic hydrocarbon (PAH) concentrations associated with vehicular traffic and facilities using diesel vehicles. Median total particulate PAH concentrations along Mexico City's roadways range from 60 to 910 ng m-3, averaged over a minimum of 1 h. These levels are approximately 5 times higher than concentrations measured in the United States and among the highest measured ambient values reported in the literature. The ratio of particulate PAH concentration to aerosol active surface area is much higher along roadways and in other areas of fresh vehicle emissions, compared to ratios measured at sites influenced more by aged emissions or noncombustion sources. For particles freshly emitted by vehicles, PAH and elem...

Journal ArticleDOI
TL;DR: Whereas the PM2.5 samples differ by their PAH and metal composition, they induce the same biological responses likely either due to components bioavailability and/ or interactions between PM components.
Abstract: Fine particulate matter present in urban areas seems to be incriminated in respiratory disorders. The aim of this study was to relate physicochemical characteristics of PM2.5 (particulate matter collected with a 50% efficiency for particles with an aerodynamic diameter of 2.5 microm) to their biological activities toward a bronchial epithelial cell line 16-HBE. Two seasonal sampling campaigns of particles were realized, respectively, in a kerbside and an urban background station in Paris. Sampled-PM2.5 mainly consist of particles with a size below 1 microm and are mainly composed of soot as assessed by analytical scanning electron microscopy. The different PM2.5 samples contrasted in their PAH content, which was the highest in the kerbside station in winter, as well as in their metal content. Kerbside station samples were characterized by the highest Fe and Cu content, which appears correlated to their hydroxyl radical generating properties measured by electron paramagnetic resonance. Particles were compared by their capacity to induce cytotoxicity, intracellular ROS production, and proinflammatory cytokine release (GM-CSF and TNF-alpha). At a concentration of 10 microg/cm2, all samples induced peroxide production and cytokine release to the similar extent in the absence of cytotoxicity. In conclusion, whereas the PM2.5 samples differ by their PAH and metal composition, they induce the same biological responses likely either due to components bioavailability and/ or interactions between PM components.

Journal ArticleDOI
TL;DR: Atmospheric particulate matter and volatile organic compounds (VOCs) from three sites surrounding a thermoelectric complex, VOCs from the power plant stack gas and aliphatic and aromatic fractions obtained from a coal sample utilized by the thermal unit of a coal-based power plant were monitored in Tubarao and Capivari de Baixo cities, State of Santa Catarina, Brazil in December 1997 as discussed by the authors.

Journal ArticleDOI
TL;DR: The Pittsburgh Air Quality Study (PAQS) was conducted from July 2001 to September 2002 as mentioned in this paper to characterize particulate matter (PM) by examination of size, surface area, and volume distribution, chemical composition as a function of size and on a single particle basis, morphology, and temporal and spatialvariabil ity in the Pittsburgh region.

Journal ArticleDOI
TL;DR: In this article, seasonal variability in the major soluble ion composition of atmospheric particulate matter in the principal sugar cane growing region of central Sao Paulo State indicates that pre-harvest burning of sugar cane plants is an important influence on the regional scale aerosol chemistry.

Journal ArticleDOI
TL;DR: In this article, the effects from the allergens, allergic and asthmatic responses may be enhanced when chemical and biological constituents of particulate matter (PM) are combined together.

Journal ArticleDOI
TL;DR: In this paper, solvent extractable compounds of urban airborne particulate matter were analyzed to determine the distributions of homologous and biomarker tracers, and the results showed that the samples contain n-alkanes, nalkan-2-ones, n -alkanols, methyl n-kanoates, n-inkanoates and n-logs.

Journal ArticleDOI
TL;DR: In this paper, an ew method is presented for fast quantification of urban pollution sources in atmospheric particulate matter (PM) using remanent magnetization of PM samples collected in Switzerland at sites with different exposures to pollution sources.
Abstract: SUMMARY An ew method is presented for fast quantification of urban pollution sources in atmospheric particulate matter (PM). The remanent magnetization of PM samples collected in Switzerland at sites with different exposures to pollution sources is analysed. The coercivity distribution of each sample is calculated from detailed demagnetization curves of anhysteretic remanent magnetization (ARM) and is modelled using a linear combination of appropriate functions which represent the contribution of different sources of magnetic minerals to the total magnetization. Two magnetic components, C1 and C2, are identified in all samples. The low-coercivity component C1 predominates in less polluted sites, whereas the concentration of the highercoercivity component C2 is large in urban areas. The same sites were monitored independently by H¨ uglin using detailed chemical analysis and a quantitative source attribution of the PM. His results are compared with the magnetic component analysis. The absolute and relative magnetic contributions of component C2 correlate very well with absolute and relative mass contributions of exhaust emissions, respectively. Traffic is the most important PM pollution source in Switzerland: it includes exhaust emissions and abrasion products released by vehicle brakes. Component C2 and traffic-related PM sources correlate well, which is encouraging for the implementation of non-destructive magnetic methods as an economic alternative to chemical analysis when mapping urban dust pollution.