Showing papers on "Particulates published in 2011"
TL;DR: The Global Fire Assimilation System (GFASv1.0) as mentioned in this paper calculates biomass burning emissions by assimilating Fire Radiative Power (FRP) observations from the MODIS instruments onboard the Terra and Aqua satellites.
Abstract: . The Global Fire Assimilation System (GFASv1.0) calculates biomass burning emissions by assimilating Fire Radiative Power (FRP) observations from the MODIS instruments onboard the Terra and Aqua satellites. It corrects for gaps in the observations, which are mostly due to cloud cover, and filters spurious FRP observations of volcanoes, gas flares and other industrial activity. The combustion rate is subsequently calculated with land cover-specific conversion factors. Emission factors for 40 gas-phase and aerosol trace species have been compiled from a literature survey. The corresponding daily emissions have been calculated on a global 0.5° × 0.5° grid from 2003 to the present. General consistency with the Global Fire Emission Database version 3.1 (GFED3.1) within its accuracy is achieved while maintaining the advantages of an FRP-based approach: GFASv1.0 makes use of the quantitative information on the combustion rate that is contained in the FRP observations, and it detects fires in real time at high spatial and temporal resolution. GFASv1.0 indicates omission errors in GFED3.1 due to undetected small fires. It also exhibits slightly longer fire seasons in South America and North Africa and a slightly shorter fire season in Southeast Asia. GFASv1.0 has already been used for atmospheric reactive gas simulations in an independent study, which found good agreement with atmospheric observations. We have performed simulations of the atmospheric aerosol distribution with and without the assimilation of MODIS aerosol optical depth (AOD). They indicate that the emissions of particulate matter need to be boosted by a factor of 2–4 to reproduce the global distribution of organic matter and black carbon. This discrepancy is also evident in the comparison of previously published top-down and bottom-up estimates. For the time being, a global enhancement of the particulate matter emissions by 3.4 is recommended. Validation with independent AOD and PM10 observations recorded during the Russian fires in summer 2010 show that the global Monitoring Atmospheric Composition and Change (MACC) aerosol model with GFASv1.0 aerosol emissions captures the smoke plume evolution well when organic matter and black carbon are enhanced by the recommended factor. In conjunction with the assimilation of MODIS AOD, the use of GFASv1.0 with enhanced emission factors quantitatively improves the forecast of the aerosol load near the surface sufficiently to allow air quality warnings with a lead time of up to four days.
940 citations
TL;DR: In this article, a review examines recent research pertinent to SSA production flux, which deals mainly with production of particles with r 80 (equilibrium radius at 80% relative humidity) less than 1 m and as small as 0.01 m.
Abstract: Knowledge of the size- and composition-dependent production flux of primary sea spray aerosol (SSA) particles and its dependence on environmental variables is required for modeling cloud microphysical properties and aerosol radiative influences, interpreting measurements of particulate matter in coastal areas and its relation to air quality, and evaluating rates of uptake and reactions of gases in sea spray drops. This review examines recent research pertinent to SSA production flux, which deals mainly with production of particles with r 80 (equilibrium radius at 80% relative humidity) less than 1 m and as small as 0.01 m. Production of sea spray particles and its dependence on controlling factors has been investigated in laboratory studies that have examined the dependences on water temperature, salinity, and the presence of organics and in field measurements with micrometeorological techniques that use newly developed fast optical particle sizers. Extensive measurements show that water-insoluble organic matter contributes substantially to the composition of SSA particles with r80 < 0.25 m and, in locations with high biological activity, can be the dominant constituent. Order-of-magnitude variation remains in estimates of the size-dependent production flux per white area, the quantity central to formulations of the production flux based on the whitecap method. This variation indicates that the production flux may depend on quantities such as the volume flux of air bubbles to the surface that are not accounted for in current models. Variation in estimates of the whitecap fraction as a function of wind speed contributes additional, comparable uncertainty to production flux estimates. © 2011 by the American Geophysical Union.
513 citations
TL;DR: In this paper, chemical composition data of particulate matter samples (TSP, PM 10 and PM 2.5 ) collected from 2002 to 2008 in the North Atlantic free troposphere at the Izana Global Atmospheric Watch (GAW) observatory (Tenerife, Canary Islands) shows that desert dust is very frequently mixed with particulate pollutants in the Saharan Air Layer (SAL).
Abstract: . An analysis of chemical composition data of particulate matter samples (TSP, PM 10 and PM 2.5 ) collected from 2002 to 2008 in the North Atlantic free troposphere at the Izana Global Atmospheric Watch (GAW) observatory (Tenerife, Canary Islands) shows that desert dust is very frequently mixed with particulate pollutants in the Saharan Air Layer (SAL). The study of this data set with Median Concentrations At Receptor (MCAR) plots allowed the identification of the potential source regions of the dust and particulate pollutants. Areas located at the south of the southern slope of the Atlas mountains emerge as the most frequent source of the soil desert dust advected to the northern edge of the SAL in summer. Industrial emissions occurring in Northern Algeria, Eastern Algeria, Tunisia and the Atlantic coast of Morocco appear as the most important source of the nitrate, ammonium and a fraction of sulphate (at least 60 % of the sulphate
210 citations
TL;DR: In this paper, the seasonal and spatial characteristics, as well as chemical composition of coarse (2.5-10μm) particulate matter (PM) were studied in the Los Angeles Basin, where 10 sampling sites were set up in different areas (urban, semi-rural, desert, near-freeway, community-based, etc).
193 citations
179 citations
TL;DR: In this paper, the atmospheric concentrations of gaseous HNO 3, HCl and NH 3 and their relative salts have been measured during two field campaigns in the winter and in the summer of 2007 at Beijing (China), as part of CAREBEIJING (Campaigns of Air Quality Research in Beijing and Surrounding Region).
Abstract: . The atmospheric concentrations of gaseous HNO 3 , HCl and NH 3 and their relative salts have been measured during two field campaigns in the winter and in the summer of 2007 at Beijing (China), as part of CAREBEIJING (Campaigns of Air Quality Research in Beijing and Surrounding Region). In this study, annular denuder technique used with integration times of 2 and 24h to collect inorganic and soluble PM 2.5 without interferences from gas–particle and particle–particle interactions. The results were discussed from the standpoint of temporal and diurnal variations and meteorological effects. Fine particulate Cl − , NH 4 + and SO 4 2− exhibited distinct temporal variations, while fine particulate NO 3 − did not show much variation with respect to season. Daily mean concentrations of fine particulate NH 4 + and SO 4 2− were higher during summer (12.30 μg m −3 and 18.24 μg m −3 , respectively) than during winter (6.51 μg m −3 and 7.50 μg m −3 , respectively). Daily mean concentrations of fine particulate Cl − were higher during winter (2.94 μg m −3 ) than during summer (0.79 μg m −3 ), while fine particulate NO 3 − showed similar both in winter (8.38 μg m −3 ) and in summer (9.62 μg m −3 ) periods. The presence of large amounts of fine particulate NO 3 − even in summer are due to higher local and regional concentrations of NH 3 in the atmosphere available to neutralize H 2 SO 4 and HNO 3 , which is consistent with the observation that the measured particulate species were neutralized. The composition of fine particulate matter indicated the domination of (NH 4 ) 2 SO 4 during winter and summer periods. In addition, the high relative humidity conditions in summer period seemed to dissolve a significant fraction of HNO 3 and NH 3 enhancing fine particulate NO 3 − and NH 4 + in the atmosphere. All measured particulate species showed diurnal similar patterns during the winter and summer periods with higher peaks in the early morning, especially in summer, when humid and stable atmospheric conditions occurred. These diurnal variations were affected by wind direction suggesting regional and local source influences. The fine particulate species were correlated with NO x and PM 2.5 , supporting the hypothesis that traffic may be also an important source of secondary particles.
176 citations
TL;DR: Examination of the effects of various PM sources on daily mortality in Barcelona suggests that traffic, sulfate from shipping and long-range transport, and construction dust are important contributors to the adverse health effects linked to PM.
Abstract: Background: Dozens of studies link acute exposure to particulate matter (PM) air pollution with premature mortality and morbidity, but questions remain about which species and sources in the vast P...
167 citations
TL;DR: This finding supports the hypothesis that long-term PM exposure may promote atherosclerosis, with air-pollution–induced increases in BP being one possible biological pathway.
Abstract: Background: Recent studies have shown an association of short-term exposure to fine particulate matter (PM) with transient increases in blood pressure (BP), but it is unclear whether long-term expo...
165 citations
TL;DR: In this paper, atmospheric acidification of aerosols is a prime mechanism producing soluble phosphorus from soil-derived minerals, which is supported by the soluble compositions and reconstructed pH values for atmospheric particulate matter samples collected over a 5-yr period at Finokalia, Crete.
Abstract: . Primary productivity of continental and marine ecosystems is often limited or co-limited by phosphorus. Deposition of atmospheric aerosols provides the major external source of phosphorus to marine surface waters. However, only a fraction of deposited aerosol phosphorus is water soluble and available for uptake by phytoplankton. We propose that atmospheric acidification of aerosols is a prime mechanism producing soluble phosphorus from soil-derived minerals. Acid mobilization is expected to be pronounced where polluted and dust-laden air masses mix. Our hypothesis is supported by the soluble compositions and reconstructed pH values for atmospheric particulate matter samples collected over a 5-yr period at Finokalia, Crete. In addition, at least tenfold increase in soluble phosphorus was observed when Saharan soil and dust were acidified in laboratory experiments which simulate atmospheric conditions. Aerosol acidification links bioavailable phosphorus supply to anthropogenic and natural acidic gas emissions, and may be a key regulator of ocean biogeochemistry.
TL;DR: In this paper, a one to one comparison between PM emitted from a mid-size engine running on petroleum-based diesel versus biodiesel was provided. And the results showed that metals that come from engine wear are not present in biodiesel exhaust particulate due to its self lubricating properties.
Abstract: Studies conducted over the last decade have well established a direct relationship between deteriorating human health and diesel engine exhaust. Biodiesel has shown a lot of promise in terms of both its relatively higher combustion efficiency and lower harmful emissions. Biodiesel has the potential to replace a significant amount of the petroleum used to power diesel engines. The emissions from biodiesel are different than petroleum-based diesel and it is important to understand how they are different with respect to the levels emitted and the combustibility of the particulates. One of the major pollutants emitted from engine exhaust is particulate matter (PM). PM emitted from tailpipes contains a variety of toxic contaminants either embedded or adsorbed on its surface. This study provides a one to one comparison between PM emitted from a mid-size engine running on petroleum-based diesel versus biodiesel. The key physical and chemical parameters analyzed include metals, benzene soluble organic fraction, elemental and organic carbon fractions, particle morphology, particle number and size distribution. This is the first study of its kind where various aspects of the PM emitted from a biodiesel-operated engine have been extensively studied. The major results from the study showed that metals that come from engine wear are not present in biodiesel exhaust particulate due to its self lubricating properties. Samples collected of mineral diesel exhaust are relatively darker in color and stickier than biodiesel exhaust. Biodiesel and its blends gave more benzene soluble organic fraction (BSOF) in engine exhaust particulate matter than mineral diesel at all operating conditions. B100 gave higher number of smaller particles in its exhaust than mineral diesel; comprehensively all size particles were also higher in case of B100. Peak particle concentrations for biodiesel were shifted towards smaller size particles. As load increases, B20 emission performance in terms of particle concentrations improves very rapidly and even surpasses mineral diesel emission performance. Scanning electron microscope (SEM) images for B100 and B20 showed granular structure particulates with bigger grain size compared to mineral diesel. Among B100, B20 and mineral diesel, total particle accumulation was maximum for mineral diesel.
TL;DR: In this paper, the authors present the first field measurements of the biomass burning emissions of glycolaldehyde, a possible precursor for aqueous phase secondary organic aerosol formation in temperate zone fires relative to tropical biomass burning.
Abstract: . We have measured emission factors for 19 trace gas species and particulate matter (PM2.5) from 14 prescribed fires in chaparral and oak savanna in the southwestern US, as well as conifer forest understory in the southeastern US and Sierra Nevada mountains of California. These are likely the most extensive emission factor field measurements for temperate biomass burning to date and the only published emission factors for temperate oak savanna fuels. This study helps to close the gap in emissions data available for temperate zone fires relative to tropical biomass burning. We present the first field measurements of the biomass burning emissions of glycolaldehyde, a possible precursor for aqueous phase secondary organic aerosol formation. We also measured the emissions of phenol, another aqueous phase secondary organic aerosol precursor. Our data confirm previous observations that urban deposition can impact the NOx emission factors and thus subsequent plume chemistry. For two fires, we measured both the emissions in the convective smoke plume from our airborne platform and the unlofted residual smoldering combustion emissions with our ground-based platform. The smoke from residual smoldering combustion was characterized by emission factors for hydrocarbon and oxygenated organic species that were up to ten times higher than in the lofted plume, including high 1,3-butadiene and isoprene concentrations which were not observed in the lofted plume. This should be considered in modeling the air quality impacts for smoke that disperses at ground level. We also show that the often ignored unlofted emissions can significantly impact estimates of total emissions. Preliminary evidence suggests large emissions of monoterpenes in the residual smoldering smoke. These data should lead to an improved capacity to model the impacts of biomass burning in similar temperate ecosystems.
TL;DR: In this paper, the total element concentration and the chemical fractionation of 18 elements (Al, As, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Ni, Pb, Rb, Sr, Ti, V, Zn) in total suspended particulate matter (TSP) from Beijing, China, were studied for a period of three years.
TL;DR: In this paper, a single particle aerosol mass spectrometer (SPAMS) was used to characterize the single particle size and chemical composition of submicron aerosols in the urban area of the Pearl River Delta region, China, for the period April 30 through May 22, 2010.
Paul Scherrer Institute1, Spanish National Research Council2, Lund University3, University of Bern4, Oeschger Centre for Climate Change Research5, University of Colorado Boulder6, Cooperative Institute for Research in Environmental Sciences7, Hungarian Academy of Sciences8, Finnish Meteorological Institute9, Autonomous University of Barcelona10, National Center for Atmospheric Research11, University of Innsbruck12, Norwegian Institute for Air Research13
TL;DR: In this article, the authors present results from the international field campaign DAURE (Determination of the sources of atmospheric Aerosols in Urban and Rural Environments in the Western Mediterranean), with the objective of apportioning the source of fine carbonaceous aerosols.
Abstract: . We present results from the international field campaign DAURE (Determination of the sources of atmospheric Aerosols in Urban and Rural Environments in the Western Mediterranean), with the objective of apportioning the sources of fine carbonaceous aerosols. Submicron fine particulate matter (PM 1 ) samples were collected during February–March 2009 and July 2009 at an urban background site in Barcelona (BCN) and at a forested regional background site in Montseny (MSY). We present radiocarbon ( 14 C) analysis for elemental and organic carbon (EC and OC) and source apportionment for these data. We combine the results with those from component analysis of aerosol mass spectrometer (AMS) measurements, and compare to levoglucosan-based estimates of biomass burning OC, source apportionment of filter data with inorganic composition + EC + OC, submicron bulk potassium (K) concentrations, and gaseous acetonitrile concentrations. At BCN, 87 % and 91 % of the EC on average, in winter and summer, respectively, had a fossil origin, whereas at MSY these fractions were 66 % and 79 %. The contribution of fossil sources to organic carbon (OC) at BCN was 40 % and 48 %, in winter and summer, respectively, and 31 % and 25 % at MSY. The combination of results obtained using the 14 C technique, AMS data, and the correlations between fossil OC and fossil EC imply that the fossil OC at Barcelona is ∼47 % primary whereas at MSY the fossil OC is mainly secondary (∼85 %). Day-to-day variation in total carbonaceous aerosol loading and the relative contributions of different sources predominantly depended on the meteorological transport conditions. The estimated biogenic secondary OC at MSY only increased by ∼40 % compared to the order-of-magnitude increase observed for biogenic volatile organic compounds (VOCs) between winter and summer, which highlights the uncertainties in the estimation of that component. Biomass burning contributions estimated using the 14 C technique ranged from similar to slightly higher than when estimated using other techniques, and the different estimations were highly or moderately correlated. Differences can be explained by the contribution of secondary organic matter (not included in the primary biomass burning source estimates), and/or by an overestimation of the biomass burning OC contribution by the 14 C technique if the estimated biomass burning EC/OC ratio used for the calculations is too high for this region. Acetonitrile concentrations correlate well with the biomass burning EC determined by 14 C. K is a noisy tracer for biomass burning.
TL;DR: Overall results show that the concentration levels of different size particulates matter are greatly affected by agricultural crop residue burning but the total distribution of the particulate matter remains almost constant.
Abstract: Emission from field burning of agricultural crop residue is a common environmental hazard observed in northern India. It has a significant potential health risk for the rural population due to respirable suspended particulate matter (RSPM). A study on eight stage size segregated mass distribution of RSPM was done for 2 wheat and 3 rice crop seasons. The study was undertaken at rural and agricultural sites of Patiala (India) where the RSPM levels remained close to the National Ambient Air quality standards (NAAQS). Fine particulate matter (PM2.5) contributed almost 55% to 64% of the RSPM, showing that, in general, the smaller particles dominated during the whole study period with more contribution during the rice crop as compared to that of wheat crop residue burning. Fine particulate matter content in the total RSPM increased with decrease in temperature. Concentration levels of PM10 and PM2.5 were higher during the winter months as compared to that in the summer months. Background concentration levels of PM10, PM2.5 and PM10−2.5 were found to be around 97±21, 57±15 and 40±6 μg m−3, respectively. The levels increased up to 66, 78 and 71% during rice season and 51, 43 and 61% during wheat crop residue burning, respectively. Extensive statistical analysis of the data was done by using pair t-test. Overall results show that the concentration levels of different size particulate matter are greatly affected by agricultural crop residue burning but the total distribution of the particulate matter remains almost constant.
TL;DR: Prasad et al. as discussed by the authors provided a survey on published information regarding diesel soot emission, its adverse effects on the human health, environment, vegetations, climate, etc.
Abstract: The diesel engines are energy efficient, but their particulate (soot) emissions are responsible of severe environmental and health problems. This review provides a survey on published information regarding diesel soot emission, its adverse effects on the human health, environment, vegetations, climate, etc. The legislations to limit diesel emissions and ways to minimize soot emission are also summarized. Soot particles are suspected to the development of cancer; cardiovascular and respiratory health effects; pollution of air, water, and soil; impact agriculture productivity, soiling of buildings; reductions in visibility; and global climate change. The review covers important recent developments on technologies for control of particulate matter (PM); diesel particulate filters (DPFs), summarizing new filter and catalyst materials and DPM measurement. DPF technology is in a state of optimization and cost reduction. New DPF regeneration strategies (active, passive and plasma-assisted regenerations) as well as the new learning on the fundamentals of soot/catalyst interaction are described. Recent developments in diesel oxidation catalysts (DOC) are also summarized showing potential issues with advanced combustion strategies, important interactions on NO2 formation, and new formulations for durability. Finally, systematic compilation of the concerned newer literature on catalytic oxidation of soot in a well conceivable tabular form is given. A total of 156 references are cited. ©2010 BCREC UNDIP. All rights reserved ( Received: 2nd June 2010, Revised: 17th June 2010; Accepted: 24th June 2010 ) [How to Cite : R. Prasad, V.R. Bella. (2010). Review on Diesel Soot Emission, its Effect and Control. Bulletin of Chemical Reaction Engineering and Catalysis , 5(2): 69-86. doi:10.9767/bcrec.5.2.794.69-86 ] [DOI: http://dx.doi.org/10.9767/bcrec.5.2.794.69-86 || or local: http://ejournal.undip.ac.id/index.php/bcrec/article/view/794 ] Cited by in: ACS 1 |
TL;DR: The size-fractionated chemical characterization of atmospheric aerosols sampled over a period of a year near an active mining and smelting site in Arizona show that arsenic and lead concentrations follow a bimodal distribution, with maxima centered at approximately 0.3 and 7.0 μm diameter, and it is hypothesize that the sub-micron arsenic andLead are the product of condensation and coagulation of Smelting vapors.
Abstract: Mining operations are potential sources of airborne metal and metalloid contaminants through both direct smelter emissions and wind erosion of mine tailings. The warmer, drier conditions predicted for the Southwestern US by climate models may make contaminated atmospheric dust and aerosols increasingly important, with potential deleterious effects on human health and ecology. Fine particulates such as those resulting from smelting operations may disperse more readily into the environment than coarser tailings dust. Fine particles also penetrate more deeply into the human respiratory system, and may become more bioavailable due to their high specific surface area. In this work, we report the size-fractionated chemical characterization of atmospheric aerosols sampled over a period of a year near an active mining and smelting site in Arizona. Aerosols were characterized with a 10-stage (0.054 to 18 μm aerodynamic diameter) multiple orifice uniform deposit impactor (MOUDI), a scanning mobility particle sizer (SMPS), and a total suspended particulate (TSP) collector. The MOUDI results show that arsenic and lead concentrations follow a bimodal distribution, with maxima centered at approximately 0.3 and 7.0 μm diameter. We hypothesize that the sub-micron arsenic and lead are the product of condensation and coagulation of smelting vapors. In the coarse size, contaminants are thought to originate as aeolian dust from mine tailings and other sources. Observation of ultrafine particle number concentration (SMPS) show the highest readings when the wind comes from the general direction of the smelting operations site.
TL;DR: The analysis presented provides direct estimations of the emissions reductions that can be realized by California fuel quality regulation and VSR program, in addition to providing new information relevant to potential health and climate impact of reduced fuel sulfur content, fuel quality and vessel speed reductions.
Abstract: Atmospheric emissions of gas and particulate matter from a large ocean-going container vessel were sampled as it slowed and switched from high-sulfur to low-sulfur fuel as it transited into regulated coastal waters of California. Reduction in emission factors (EFs) of sulfur dioxide (SO2), particulate matter, particulate sulfate and cloud condensation nuclei were substantial (≥90%). EFs for particulate organic matter decreased by 70%. Black carbon (BC) EFs were reduced by 41%. When the measured emission reductions, brought about by compliance with the California fuel quality regulation and participation in the vessel speed reduction (VSR) program, are placed in a broader context, warming from reductions in the indirect effect of SO4 would dominate any radiative changes due to the emissions changes. Within regulated waters absolute emission reductions exceed 88% for almost all measured gas and particle phase species. The analysis presented provides direct estimations of the emissions reductions that can be...
TL;DR: In this article, the authors used Positive Matrix Factorization (PMF) to measure the seasonal source contributions from seasonally segregated data using EPA-PMF modeling so that further policy interventions can be undertaken to improve air quality.
TL;DR: The results suggest that not only can the sources of the particulate influence the presence of specific bacterial groups but also that environmental factors and stresses can shape the bacterial community.
Abstract: The current knowledge about the microbial communities associated with airborne particulate matter, particularly in urban areas, is limited. This study aims to fill this gap by describing the microbial community associated with coarse (PM10) and fine (PM2.5) particulate matter using pyrosequencing. Particulate matter was sampled on Teflon filters over 3 months in summer and 3 months in winter in Milan (Italy), and the hypervariable V3 region of the gene 16S rRNA amplified from the DNA extracted from the filters. The results showed large seasonal variations in the microbial communities, with plant-associated bacteria dominating in summer and spore-forming bacteria in winter. Bacterial communities from PM10 and PM2.5 were also found to differ from each other by season. In all samples, a high species richness, comparable with that of soils, but a low evenness was found. The results suggest that not only can the sources of the particulate influence the presence of specific bacterial groups but also that environmental factors and stresses can shape the bacterial community.
AVL1
TL;DR: PAHs diagnostic ratios suggested that PAHs mainly originated from the inputs of pyrolytic (combustion) sources, which might be contributed to land-based atmospheric deposition.
Colorado State University1, Georgia Institute of Technology2, Carnegie Mellon University3, Cooperative Institute for Research in Environmental Sciences4, Langley Research Center5, University of Innsbruck6, National Center for Atmospheric Research7, California Institute of Technology8, Goethe University Frankfurt9
TL;DR: In this article, the authors compared measurements of gaseous and particulate emissions from a wide range of biomass-burning plumes intercepted by the NASA DC-8 research aircraft during the three phases of the ARCTAS-2008 experiment.
Abstract: This paper compares measurements of gaseous and particulate emissions from a wide range of biomass-burning plumes intercepted by the NASA DC-8 research aircraft during the three phases of the ARCTAS-2008 experiment: ARCTAS-A, based out of Fairbanks, Alaska, USA (3 April to 19 April 2008); ARCTAS-B based out of Cold Lake, Alberta, Canada (29 June to 13 July 2008); and ARCTAS-CARB, based out of Palmdale, California, USA (18 June to 24 June 2008). Approximately 500 smoke plumes from biomass burning emissions that varied in age from minutes to days were segregated by fire source region and urban emission influences. The normalized excess mixing ratios (NEMR) of gaseous (carbon dioxide, acetonitrile, hydrogen cyanide, toluene, benzene, methane, oxides of nitrogen and ozone) and fine aerosol particulate components (nitrate, sulfate, ammonium, chloride, organic aerosols and water soluble organic carbon) of these plumes were compared. A detailed statistical analysis of the different plume categories for different gaseous and aerosol species is presented in this paper.
The comparison of NEMR values showed that CH4 concentrations were higher in air-masses that were influenced by urban emissions. Fresh biomass burning plumes mixed with urban emissions showed a higher degree of oxidative processing in comparison with fresh biomass burning only plumes. This was evident in higher concentrations of inorganic aerosol components such as sulfate, nitrate and ammonium, but not reflected in the organic components. Lower NOx NEMRs combined with high sulfate, nitrate and ammonium NEMRs in aerosols of plumes subject to long-range transport, when comparing all plume categories, provided evidence of advanced processing of these plumes.
TL;DR: In this paper, the concentrations of sixteen polycyclic aromatic hydrocarbons (PAHs) and trace metals adsorbed to respirable particulate matter (PM≤ 10μm) and the fine fraction of PM≤ 2.5μm were determined at a site in Delhi (India) during the winter and summer periods in 2007-2008.
TL;DR: In this paper, a dichotomous sampler was used for the simultaneous collection of atmospheric particulates in coarse and fine size fractions using Proton Induced X-ray Emission (PIXE) technique.
Abstract: Particulate matter samples were collected using a dichotomous sampler at a residential area of Vashi situated in Navi Mumbai, India during the period of 2008. The sampler facilitates the simultaneous collection of atmospheric particulates in coarse and fine size fractions. The filter samples collected were analysed for trace elements using Proton Induced X-ray Emission (PIXE) technique. The particulate matter trends show higher concentration during winter season compared to other seasons. High concentrations of elements related to soil and sea salt were found in the coarse fraction of particulate matter. Enrichment Factor (EF) analysis with respect to Fe showed enrichment of Cu, Cr, and Mn only in the fine fraction suggesting their origin from anthropogenic sources. The EF value was observed to be maximum for As, Pb and Zn in the fine particulates. However, crustal and marine derived elements showed very low EF values indicating their origin from soil and sea salt respectively. The Principal Component Analysis (PCA) based multivariate studies identified soil, sea salt and combustion as common sources for coarse and fine particles. Additionaly a source contributing to coarse fraction Br concentration as well as an industrial and Se source contributing to fine fraction particles has been identified.
01 Jan 2011
TL;DR: In this paper, the authors quantified natural and anthropogenic sources of particulate organic carbon (OCp) and elemental carbon (EC) based on weekly filter samples of PM10 (particles with aerodynamic diameter <10 µm) collected at four Nordic rural background sites (Birkenes (Norway), Hyyti al¨ a (Finland), Vavihill (Sweden), Lille Valby, (Denmark)) during late summer (5 August-2 September 2009).
Abstract: In the present study, natural and anthropogenic sources of particulate organic carbon (OCp) and elemental carbon (EC) have been quantified based on weekly filter samples of PM10 (particles with aerodynamic diameter <10 µm) collected at four Nordic rural background sites (Birkenes (Norway), Hyyti¨ al¨ a (Finland), Vavihill (Sweden), Lille Valby, (Denmark)) during late summer (5 August-2 September 2009). Levels of source specific tracers, i.e. cellulose, levoglucosan, mannitol and the 14 C/ 12 C ratio of total carbon (TC), have been used as input for source apportionment of the carbonaceous aerosol, whereas Latin Hypercube Sampling (LHS) was used to statistically treat the multitude of possible combinations resulting from this approach. The carbonaceous aerosol (here: TCp; i.e. particulate TC) was totally dominated by natural sources (69-86 %), with biogenic secondary organic aerosol (BSOA) being the single most important source (48-57 %). Interestingly, primary biological aerosol particles (PBAP) were the second most important source (20-32 %). The anthropogenic contribution was mainly attributed to fossil fuel sources (OCff and ECff) (10-24 %), whereas no more than 3-7 % was explained by combustion of biomass (OCbb and ECbb) in this late summer campaign i.e. emissions from residential wood burning and/or wild/agricultural fires. Fossil fuel sources totally dominated the ambient EC loading, which accounted for 4-12 % of TCp, whereas <1.5 % of EC was attributed to combustion of biomass. The carbonaceous aerosol source apportionment showed only minor variation between the four selected sites. However, Hyyti¨¨ and Birkenes showed greater resemblance to each other, as did Lille Valby and Vavihill, the two latter being somewhat more influenced by anthropogenic sources. Ambient levels of organosulphates and nitrooxy-organosulphates in the Nordic rural background environment are reported for the first time in the present study. The most abundant organosulphate compounds were an organosulphate of isoprene and nitrooxy-organosulphates of - and -pinene and limonene.
TL;DR: The carcinogenic character of the airborne PM10 of Zaragoza was studied during 2003-2004 by determining the concentration of BaP equivalents (BaP-eq), using toxic equivalent factors provided by Larsen and Larsen.