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Sample records for aerosol source apportionment

  1. Synthesizing Scientific Progress: Outcomes from US EPA’s Carbonaceous Aerosols and Source Apportionment STAR Grants

    EPA Science Inventory

    ABSTRACTA number of studies in the past decade have transformed the way we think about atmospheric aerosols. The advances include, but are not limited to, source apportionment of organics using aerosol mass spectrometer data, the volatility basis set approach, quantifying isopre...

  2. Characterization and source apportionment of organic aerosol using offline aerosol mass spectrometry

    NASA Astrophysics Data System (ADS)

    Daellenbach, K. R.; Bozzetti, C.; Křepelová, A.; Canonaco, F.; Wolf, R.; Zotter, P.; Fermo, P.; Crippa, M.; Slowik, J. G.; Sosedova, Y.; Zhang, Y.; Huang, R.-J.; Poulain, L.; Szidat, S.; Baltensperger, U.; Prévôt, A. S. H.; El Haddad, I.

    2015-08-01

    Field deployments of the Aerodyne Aerosol Mass Spectrometer (AMS) have significantly advanced real-time measurements and source apportionment of non-refractory particulate matter. However, the cost and complex maintenance requirements of the AMS make impractical its deployment at sufficient sites to determine regional characteristics. Furthermore, the negligible transmission efficiency of the AMS inlet for supermicron particles significantly limits the characterization of their chemical nature and contributing sources. In this study, we utilize the AMS to characterize the water-soluble organic fingerprint of ambient particles collected onto conventional quartz filters, which are routinely sampled at many air quality sites. The method was applied to 256 particulate matter (PM) filter samples (PM1, PM2.5, PM10) collected at 16 urban and rural sites during summer and winter. We show that the results obtained by the present technique compare well with those from co-located online measurements, e.g. AMS or Aerosol Chemical Speciation Monitor (ACSM). The bulk recoveries of organic aerosol (60-91 %) achieved using this technique, together with low detection limits (0.8 μg of organic aerosol on the analyzed filter fraction) allow its application to environmental samples. We will discuss the recovery variability of individual hydrocarbon, oxygen containing and other ions. The performance of such data in source apportionment is assessed in comparison to ACSM data. Recoveries of organic components related to different sources as traffic, wood burning and secondary organic aerosol are presented. This technique, while subjected to the limitations inherent to filter-based measurements (e.g. filter artifacts and limited time resolution) may be used to enhance the AMS capabilities in measuring size-fractionated, spatially-resolved long-term datasets.

  3. Characterization and source apportionment of organic aerosol using offline aerosol mass spectrometry

    NASA Astrophysics Data System (ADS)

    Daellenbach, K. R.; Bozzetti, C.; Křepelová, A.; Canonaco, F.; Wolf, R.; Zotter, P.; Fermo, P.; Crippa, M.; Slowik, J. G.; Sosedova, Y.; Zhang, Y.; Huang, R.-J.; Poulain, L.; Szidat, S.; Baltensperger, U.; El Haddad, I.; Prévôt, A. S. H.

    2016-01-01

    Field deployments of the Aerodyne Aerosol Mass Spectrometer (AMS) have significantly advanced real-time measurements and source apportionment of non-refractory particulate matter. However, the cost and complex maintenance requirements of the AMS make its deployment at sufficient sites to determine regional characteristics impractical. Furthermore, the negligible transmission efficiency of the AMS inlet for supermicron particles significantly limits the characterization of their chemical nature and contributing sources. In this study, we utilize the AMS to characterize the water-soluble organic fingerprint of ambient particles collected onto conventional quartz filters, which are routinely sampled at many air quality sites. The method was applied to 256 particulate matter (PM) filter samples (PM1, PM2.5, and PM10, i.e., PM with aerodynamic diameters smaller than 1, 2.5, and 10 µm, respectively), collected at 16 urban and rural sites during summer and winter. We show that the results obtained by the present technique compare well with those from co-located online measurements, e.g., AMS or Aerosol Chemical Speciation Monitor (ACSM). The bulk recoveries of organic aerosol (60-91 %) achieved using this technique, together with low detection limits (0.8 µg of organic aerosol on the analyzed filter fraction) allow its application to environmental samples. We will discuss the recovery variability of individual hydrocarbon ions, ions containing oxygen, and other ions. The performance of such data in source apportionment is assessed in comparison to ACSM data. Recoveries of organic components related to different sources as traffic, wood burning, and secondary organic aerosol are presented. This technique, while subjected to the limitations inherent to filter-based measurements (e.g., filter artifacts and limited time resolution) may be used to enhance the AMS capabilities in measuring size-fractionated, spatially resolved long-term data sets.

  4. Carbon isotope based aerosol source apportionment in Eastern European city Vilnius

    NASA Astrophysics Data System (ADS)

    Garbaras, Andrius; Sapolaite, Justina; Garbariene, Inga; Ezerinskis, Zilvinas; Pocevicius, Matas; Krikscikas, Laurynas; Jacevicius, Sarunas; Plukis, Arturas; Remeikis, Vidmantas

    2016-04-01

    We present carbonaceous aerosol source apportionment results in Eastern European city Vilnius (capital of Lithuania) using stable carbon isotope ratio (δ13C) and radiocarbon (14C) methods. The aerosol sampling campaigns were performed in 2014-2016 winter seasons in Vilnius. PM1 particles were collected on quartz fiber filters using high volume sampler, while PM10 and size segregated aerosol particles were collected using low volume and MOUDI 128 cascade impactor respectively. δ13C values were measured with EA-IRMS system while radiocarbon analysis was performed using Single Stage Accelerator Mass Spectrometer (SSAMS). For the AMS analysis, filters (or aluminium foils from cascade impactor) were graphitized using Automated Graphitization Equipment. It was estimated that dominant carbonaceous aerosol source in Vilnius was of biogenic/biomass origin (60-90 %). Fossil fuel sources accounted for up to 23 % of total carbon fraction. Combining stable carbon and radiocarbon isotope analysis we were able to quantify the amount of coal derived aerosol particles. The contribution of coal burning emissions were up to 14 %. We will present the applicability of dual carbon (13C and 14C) isotope ratio method for the aerosol source apportionment in different regions of Europe, also the perspectives of using MOUDI cascade impactors to make source apportionment in size segregated aerosol particles.

  5. Single particle characterization, source apportionment, and aging effects of ambient aerosols in Southern California

    NASA Astrophysics Data System (ADS)

    Shields, Laura Grace

    Composed of a mixture of chemical species and phases and existing in a variety of shapes and sizes, atmospheric aerosols are complex and can have serious influence on human health, the environment, and climate. In order to better understand the impact of aerosols on local to global scales, detailed measurements on the physical and chemical properties of ambient particles are essential. In addition, knowing the origin or the source of the aerosols is important for policymakers to implement targeted regulations and effective control strategies to reduce air pollution in their region. One of the most ground breaking techniques in aerosol instrumentation is single particle mass spectrometry (SPMS), which can provide online chemical composition and size information on the individual particle level. The primary focus of this work is to further improve the ability of one specific SPMS technique, aerosol time-of-flight mass spectrometry (ATOFMS), for the use of identifying the specific origin of ambient aerosols, which is known as source apportionment. The ATOFMS source apportionment method utilizes a library of distinct source mass spectral signatures to match the chemical information of the single ambient particles. The unique signatures are obtained in controlled source characterization studies, such as with the exhaust emissions of heavy duty diesel vehicles (HDDV) operating on a dynamometer. The apportionment of ambient aerosols is complicated by the chemical and physical processes an individual particle can undergo as it spends time in the atmosphere, which is referred to as "aging" of the aerosol. Therefore, the performance of the source signature library technique was investigated on the ambient dataset of the highly aged environment of Riverside, California. Additionally, two specific subsets of the Riverside dataset (ultrafine particles and particles containing trace metals), which are known to cause adverse health effects, were probed in greater detail. Finally

  6. Source apportionment of the summer time carbonaceous aerosol at Nordic rural background sites

    NASA Astrophysics Data System (ADS)

    Yttri, K. E.; Simpson, D.; Nøjgaard, J. K.; Kristensen, K.; Genberg, J.; Stenström, K.; Swietlicki, E.; Hillamo, R.; Aurela, M.; Bauer, H.; Offenberg, J. H.; Jaoui, M.; Dye, C.; Eckhardt, S.; Burkhart, J. F.; Stohl, A.; Glasius, M.

    2011-06-01

    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 collected at four Nordic rural background sites (Birkenes (Norway), Hyytiälä (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 14C/12C 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, accounting for 4-12 % of TCp, whereas <1.5 % was attributed to combustion of biomass. The carbonaceous aerosol source apportionment showed only minor variation between the four selected sites. However, Hyytiälä 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

  7. Quantification and radiocarbon source apportionment of black carbon in atmospheric aerosols using the CTO-375 method

    NASA Astrophysics Data System (ADS)

    Zencak, Zdenek; Elmquist, Marie; Gustafsson, Örjan

    To make progress towards linking the atmosphere and biogeosphere parts of the black carbon (BC) cycle, a chemothermal oxidation method (CTO-375), commonly applied for isolating BC from complex geomatrices such as soils, sediments and aquatic particles, was applied to investigate the BC also in atmospheric particles. Concentrations and 14C-based source apportionment of CTO-375 based BC was established for a reference aerosol (NIST RM-8785) and for wintertime aerosols collected in Stockholm and in a Swedish background area. The results were compared with thermal-optical (OC/EC) measurements. For NIST RM-8785, a good agreement was found between the BC CTO-375 concentration and the reported elemental carbon (EC) concentration measured by the "Speciation Trends Network—National Institute of Occupational Safety and Health" method (EC NIOSH) with BC CTO-375 of 0.054±0.002 g g -1 and EC NIOSH of 0.067±0.008 g g -1. In contrast, there was an average factor of ca. 20 difference between BC CTO-375 and EC NIOSH for the ambient Scandinavian wintertime aerosols, presumably reflecting a combination of BC CTO-375 isolating only the recalcitrant soot-BC portion of the BC continuum and the EC NIOSH metric inadvertently including some intrinsically non-pyrogenic organic matter. Isolation of BC CTO-375 with subsequent off-line radiocarbon analysis yielded fraction modern values (fM) for total organic carbon (TOC) of 0.93 (aerosols from a Swedish background area), and 0.58 (aerosols collected in Stockholm); whereas the fM for BC CTO-375 isolates were 1.08 (aerosols from a Swedish background area), and 0.87 (aerosols collected in Stockholm). This radiocarbon-based source apportionment suggests that contribution from biomass combustion to cold-season atmospheric BC CTO-375 in Stockholm was 70% and in the background area 88%.

  8. Source apportionment of the summer time carbonaceous aerosol at Nordic rural background sites

    NASA Astrophysics Data System (ADS)

    Yttri, K. E.; Simpson, D.; Nøjgaard, J. K.; Kristensen, K.; Genberg, J.; Stenström, K.; Swietlicki, E.; Hillamo, R.; Aurela, M.; Bauer, H.; Offenberg, J. H.; Jaoui, M.; Dye, C.; Eckhardt, S.; Burkhart, J. F.; Stohl, A.; Glasius, M.

    2011-12-01

    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), Hyytiälä (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 14C/12C 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, Hyytiälä 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

  9. Isotope source apportionment of carbonaceous aerosol as a function of particle size and thermal refractiveness

    NASA Astrophysics Data System (ADS)

    Masalaite, Agne; Holzinger, Rupert; Remeikis, Vidmantas; Röckmann, Thomas; Dusek, Ulrike

    2016-04-01

    The stable carbon isotopes can be used to get information about sources and processing of carbonaceous aerosol. We will present results from source apportionment of carbonaceous aerosol as a function of particle size thermal refractiveness. Separate source apportionment for particles smaller than 200 nm and for different carbon volatility classes are rarely reported and give new insights into aerosol sources in the urban environment. Stable carbon isotope ratios were measured for the organic carbon (OC) fraction and total carbon (TC) of MOUDI impactor samples that were collected on a coastal site (Lithuania) during the winter 2012 and in the city of Vilnius (Lithuania) during the winter of 2009. The 11 impactor stages spanned a size range from 0.056 to 18 μm, but only the 6 stages in the submicron range were analysed. The δ13C values of bulk total carbon (δ13CTC) were determined with an elemental analyser (Flash EA 1112) coupled with an isotope ratio mass spectrometer (Thermo Finnigan Delta Plus Advantage) (EA - IRMS). Meanwhile δ13COC was measured using thermal-desorption isotope ratio mass spectrometry (IRMS) system. This allows a rough separation of the more volatile OC fraction (desorbed in the oven of IRMS up to 250 0C) from the more refractory fraction (desorbed up to 400 0C). In this study we investigated the composition of organic aerosol desorbed from filter samples at different temperatures using the thermal-desorption proton-transfer-reaction mass spectrometry (TD-PTR-MS) technique. During winter-time in Lithuania we expect photochemistry and biogenic emissions to be of minor importance. The main sources of aerosol carbon should be fossil fuel and biomass combustion. In both sites, the coastal and the urban site, δ13C measurements give a clear indication that the source contributions differ for small and large particles. Small particles < 200 nm are depleted in 13C with respect to larger particles by 1 - 2 ‰Ṫhis shows that OC in small particle

  10. Aerosol source apportionment from 1 year measurements at the CESAR tower at Cabauw, NL

    NASA Astrophysics Data System (ADS)

    Schlag, P.; Kiendler-Scharr, A.; Blom, M. J.; Canonaco, F.; Henzing, J. S.; Moerman, M. M.; Prévôt, A. S. H.; Holzinger, R.

    2015-12-01

    Intensive measurements of submicron aerosol particles and their chemical composition were performed with an Aerosol Chemical Speciation Monitor (ACSM) at the Cabauw Experimental Site for Atmospheric Research (CESAR) in Cabauw, NL. The campaign lasted nearly one year from July 2012 to June 2013 as part of the ACTRIS project. Including black carbon data an average particulate mass concentration of 9.50 μg m-3 was obtained during the whole campaign with dominant contributions from ammonium nitrate (45 %), organic aerosol (OA, 29 %), and ammonium sulfate (19 %). 12 exceedances of the World Health Organization (WHO) PM2.5 daily mean limit (25 μg m-3) were observed at this rural site using PM1 instrumentation only. Ammonium nitrate and OA represented the largest contributors to total particulate matter during periods of exceedance. Source apportionment of OA was performed season-wise by Positive Matrix Factorization (PMF) using the Multilinear Engine 2 (ME-2) controlled via the source finder (SoFi). Primary organic aerosols were attributed mainly to traffic (8-16 % contribution to total OA, averaged season-wise) and biomass burning (0-23 %). Secondary organic aerosols (SOA, 61-84 %) dominated the organic fraction during the whole campaign, particularly on days with high mass loadings. A SOA factor which is attributed to humic-like substances (HULIS) was identified as a highly oxidized background aerosol in Cabauw. This shows the importance of atmospheric ageing processes for aerosol concentration at this rural site. Due to the large secondary fraction, the reduction of particulate mass at this rural site is challenging on a local scale.

  11. Aerosol source apportionment from 1-year measurements at the CESAR tower in Cabauw, the Netherlands

    NASA Astrophysics Data System (ADS)

    Schlag, Patrick; Kiendler-Scharr, Astrid; Blom, Marcus Johannes; Canonaco, Francesco; Sebastiaan Henzing, Jeroen; Moerman, Marcel; Prévôt, André Stephan Henry; Holzinger, Rupert

    2016-07-01

    Intensive measurements of submicron aerosol particles and their chemical composition were performed with an Aerosol Chemical Speciation Monitor (ACSM) at the Cabauw Experimental Site for Atmospheric Research (CESAR) in Cabauw, the Netherlands, sampling at 5 m height above ground. The campaign lasted nearly 1 year from July 2012 to June 2013 as part of the EU-FP7-ACTRIS project (Q-ACSM Network). Including equivalent black carbon an average particulate mass concentration of 9.50 µg m-3 was obtained during the whole campaign with dominant contributions from ammonium nitrate (45 %), organic aerosol (OA, 29 %), and ammonium sulfate (19 %). There were 12 exceedances of the World Health Organization (WHO) PM2.5 daily mean limit (25 µg m-3) observed at this rural site using PM1 instrumentation only. Ammonium nitrate and OA represented the largest contributors to total particulate matter during periods of exceedance. Source apportionment of OA was performed season-wise by positive matrix factorization (PMF) using the multilinear engine 2 (ME-2) controlled via the source finder (SoFi). Primary organic aerosols were attributed mainly to traffic (8-16 % contribution to total OA, averaged season-wise) and biomass burning (0-23 %). Secondary organic aerosols (SOAs, 61-84 %) dominated the organic fraction during the whole campaign, particularly on days with high mass loadings. A SOA factor which is attributed to humic-like substances (HULIS) was identified as a highly oxidized background aerosol in Cabauw. This shows the importance of atmospheric aging processes for aerosol concentration at this rural site. Due to the large secondary fraction, the reduction of particulate mass at this rural site is challenging on a local scale.

  12. Source apportionment of carbonaceous aerosols over South and East Asia using dual carbon isotopes

    NASA Astrophysics Data System (ADS)

    Gustafsson, O.; Kirillova, E. N.; Andersson, A.-; Kruså, M.; Sheesley, R. J.; Tiwari, S.-; Lee, M.; Chen, B.; Du, K.

    2012-12-01

    Emissions of black carbon (BC) and other components of carbonaceous aerosols affect both climate and health in South and East Asia, yet substantial uncertainties exist regarding their sources. The relative contribution to atmospheric BC from fossil fuel versus biomass combustion is important to constrain both to direct mitigation and as their different properties make their effects on climate forcing and respiratory health different. This study approached the sourcing challenge by applying microscale radiocarbon measurements to aerosol particles collected in both source regions and at regional receptor observatories of both S Asia (New Delhi and the Maldives Climate Observatory) and of E Asia (Beijing, Shanghai, South China Coastal Observatory and the Korea Climate Observatory - Gosan, KCO-G, Jeju Island). The radiocarbon approach is ideally suited to this task as fossil sources are void of 14C whereas biomass combustion products hold a contemporary 14C signal. For S Asia, the 14C-based observations suggest that biomass combustion contributes half to two-thirds of the BC loading. In contrast, for E Asia, fossil fuel combustion account for four-fifths of the BC emitted from China. This source-diagnostic radiocarbon signal in the ambient aerosol over East Asia establishes a much larger role for fossil fuel combustion than suggested by all fifteen BC emission inventory models. There are also poor constraints on the sources of water-soluble organic carbon (WSOC), a large hydrophilic component of carbonaceous aerosols that enhances the propensity of aerosols to form clouds. In a 15-mo continuous campaign in S Asia, radiocarbon-based source apportionment of WSOC shows the dominance of biogenic/biomass combustion sources but also a substantial anthropogenic fossil-fuel contribution (about 20%). WSOC in E Asia reaching KCO-G were 50% from fossil sources. Aerosols reaching the Maldives after long-range over-ocean transport were enriched by 3-4‰ in δ13C-WSOC. This is

  13. Biomass burning in the Amazon region: Aerosol source apportionment and associated health risk assessment

    NASA Astrophysics Data System (ADS)

    de Oliveira Alves, Nilmara; Brito, Joel; Caumo, Sofia; Arana, Andrea; de Souza Hacon, Sandra; Artaxo, Paulo; Hillamo, Risto; Teinilä, Kimmo; Batistuzzo de Medeiros, Silvia Regina; de Castro Vasconcellos, Pérola

    2015-11-01

    The Brazilian Amazon represents about 40% of the world's remaining tropical rainforest. However, human activities have become important drivers of disturbance in that region. The majority of forest fire hotspots in the Amazon arc due to deforestation are impacting the health of the local population of over 10 million inhabitants. In this study we characterize western Amazonia biomass burning emissions through the quantification of 14 Polycyclic Aromatic Hydrocarbons (PAHs), Organic Carbon, Elemental Carbon and unique tracers of biomass burning such as levoglucosan. From the PAHs dataset a toxic equivalence factor is calculated estimating the carcinogenic and mutagenic potential of biomass burning emissions during the studied period. Peak concentration of PM10 during the dry seasons was observed to reach 60 μg m-3 on the 24 h average. Conversely, PM10 was relatively constant throughout the wet season indicating an overall stable balance between aerosol sources and sinks within the filter sampling resolution. Similar behavior is identified for OC and EC components. Levoglucosan was found in significant concentrations (up to 4 μg m-3) during the dry season. Correspondingly, the estimated lung cancer risk calculated during the dry seasons largely exceeded the WHO health-based guideline. A source apportionment study was carried out through the use of Absolute Principal Factor Analysis (APFA), identifying a three-factor solution. The biomass burning factor is found to be the dominating aerosol source, having 75.4% of PM10 loading. The second factor depicts an important contribution of several PAHs without a single source class and therefore was considered as mixed sources factor, contributing to 6.3% of PM10. The third factor was mainly associated with fossil fuel combustion emissions, contributing to 18.4% of PM10. This work enhances the knowledge of aerosol sources and its impact on climate variability and local population, on a site representative of the

  14. Source apportionment of PM2.5 carbonaceous aerosol in Baghdad, Iraq

    NASA Astrophysics Data System (ADS)

    Hamad, Samera Hussein; Schauer, James Jay; Heo, Jongbae; Kadhim, Ahmed K. H.

    2015-04-01

    Baghdad is the second largest city in the Middle East and suffers from severe air quality degradation due to the high levels of the atmospheric particulate matter (PM). Limited information exists regarding the sources of PM in Baghdad, and the lack of information on sources inhibits the development of control strategies to reduce air pollution. To better understand the nature of fine particulate matter (PM2.5) in Baghdad and the Middle East, a one year sampling campaign to collect PM2.5 was conducted from September 2012 through September 2013, missing August 2013 samples due to the security situation. 24-hour integrated samples collected on a 1-in-6 day schedule were analyzed for the major components, and monthly average samples were analyzed by gas chromatography mass spectrometry (GCMS) methods to measure particle-phase organic molecular markers. The results of organic molecular markers were used in a chemical mass balance (CMB) model to quantify the sources of PM2.5 organic carbon (OC) and PM2.5 mass. Primary sources accounted for 44% of the measured PM2.5, and secondary sources were estimated to make up 28% of the measured PM2.5. Picene, a tracer of coal combustion detected in Baghdad where there is no evidence for coal combustion, can be attributed to burning crude oil and other low quality fuels in Baghdad. Source apportionment results showed that the dominant sources of the carbonaceous aerosols in Baghdad are gasoline (37 ± 6%) and diesel engines (17 ± 3%) which can be attributed to the extensive use of gasoline and diesel powered generators in Baghdad. Wood burning and residual oil combustion contributed to 5 ± 0.4 and 1 ± 0.2% respectively of OC. The unresolved sources contributed to 42 ± 19% of the OC which represented the secondary organic aerosol (SOA) and the unidentified sources.

  15. Organic aerosol components derived from 25 AMS data sets across Europe using a consistent ME-2 based source apportionment approach

    NASA Astrophysics Data System (ADS)

    Crippa, M.; Canonaco, F.; Lanz, V. A.; Äijälä, M.; Allan, J. D.; Carbone, S.; Capes, G.; Ceburnis, D.; Dall'Osto, M.; Day, D. A.; DeCarlo, P. F.; Ehn, M.; Eriksson, A.; Freney, E.; Hildebrandt Ruiz, L.; Hillamo, R.; Jimenez, J. L.; Junninen, H.; Kiendler-Scharr, A.; Kortelainen, A.-M.; Kulmala, M.; Laaksonen, A.; Mensah, A. A.; Mohr, C.; Nemitz, E.; O'Dowd, C.; Ovadnevaite, J.; Pandis, S. N.; Petäjä, T.; Poulain, L.; Saarikoski, S.; Sellegri, K.; Swietlicki, E.; Tiitta, P.; Worsnop, D. R.; Baltensperger, U.; Prévôt, A. S. H.

    2014-06-01

    Organic aerosols (OA) represent one of the major constituents of submicron particulate matter (PM1) and comprise a huge variety of compounds emitted by different sources. Three intensive measurement field campaigns to investigate the aerosol chemical composition all over Europe were carried out within the framework of the European Integrated Project on Aerosol Cloud Climate and Air Quality Interactions (EUCAARI) and the intensive campaigns of European Monitoring and Evaluation Programme (EMEP) during 2008 (May-June and September-October) and 2009 (February-March). In this paper we focus on the identification of the main organic aerosol sources and we define a standardized methodology to perform source apportionment using positive matrix factorization (PMF) with the multilinear engine (ME-2) on Aerodyne aerosol mass spectrometer (AMS) data. Our source apportionment procedure is tested and applied on 25 data sets accounting for two urban, several rural and remote and two high altitude sites; therefore it is likely suitable for the treatment of AMS-related ambient data sets. For most of the sites, four organic components are retrieved, improving significantly previous source apportionment results where only a separation in primary and secondary OA sources was possible. Generally, our solutions include two primary OA sources, i.e. hydrocarbon-like OA (HOA) and biomass burning OA (BBOA) and two secondary OA components, i.e. semi-volatile oxygenated OA (SV-OOA) and low-volatility oxygenated OA (LV-OOA). For specific sites cooking-related (COA) and marine-related sources (MSA) are also separated. Finally, our work provides a large overview of organic aerosol sources in Europe and an interesting set of highly time resolved data for modeling purposes.

  16. Source apportionment of carbonaceous aerosol in Sao Paulo using 13C and 14C measurements

    NASA Astrophysics Data System (ADS)

    Oyama, Beatriz; Andrade, Maria de Fatima; Holzinger, Rupert; Röckmann, Thomas; Meijer, Harro A. J.; Dusek, Ulrike

    2016-04-01

    The Metropolitan Area of Sao Paulo is affected by high aerosol concentrations, which contain a large fraction of organic material. Up to date, not much is known about the composition and origin of the organic aerosol in this city. We present the first source apportionment of the carbonaceous aerosol fraction in Sao Paulo, using stable (13C) and radioactive carbon isotopes (14C). 14C provides a clear-cut distinction between fossil sources, which contain no 14C, and contemporary sources such as biofuels, biomass burning, or biogenic sources, which contain a typical contemporary 14C/12C ratio. 13C can be used to distinguish C3 plants, such as maize and sugarcane, from C4 plants. This can help to identify a possible impact of sugarcane field burning in the rural areas of Sao Paulo State on the aerosol carbon in the city. In the first part of the study, we compare two tunnel studies: Tunnel 1 is frequented only by light duty vehicles, which run mainly on mixtures of gasoline with ethanol (gasohol, 25% ethanol and 85% gasoline) or hydrated ethanol (5% water and 95% ethanol). Tunnel 2 contains a significant fraction of heavy-duty diesel vehicles, and therefore the fraction of biofuels in the average fleet is lower. Comparison of 14C in organic and elemental carbon (OC and EC) shows that in both tunnels there is no significant contribution of biofuels to EC. Combusting ethanol-gasoline fuels in a vehicle engine does apparently not result in significant EC formation from ethanol. Biofuels contribute around 45% to OC in Tunnel 1 an only 20% in Tunnel 2, reflecting a strong impact of diesel vehicles in Tunnel 2. In the second part of the study we conduct a source apportionment of ambient aerosol carbon collected in a field study during winter (July-August) 2012. Ambient EC has two main sources, vehicular emissions and biomass burning. We estimate a contribution of vehicular sources to EC of roughly 90% during weekdays and 80% during weekends, using the 14C values measured in

  17. Source apportionment of aerosol particles near a steel plant by electron microscopy.

    PubMed

    Ebert, Martin; Müller-Ebert, Dörthe; Benker, Nathalie; Weinbruch, Stephan

    2012-12-01

    The size, morphology and chemical composition of 37,715 individual particles collected over 22 sampling days in the vicinity of a large integrated steel production were studied by scanning and transmission electron microscopy. Based on the morphology, chemistry and beam stability the particles were classified into the following fourteen groups: silicates, sea salt, calcium sulfates, calcium carbonates, carbonate-silicate mixtures, sulfate-silicate mixtures, iron oxides, iron mixtures, metal oxide-metals, complex secondary particles, soot, Cl-rich particles, P-rich particles, and other particles. The majority of iron oxide (≈85%) and metal oxide-metal (≈70%) particles as well as ≈20% of the silicate particles are fly ashes from high temperature processes. The emissions from the steel work are dominated by iron oxide particles. For source apportionment, seven source categories and two sectors of local wind direction (industrial and urban background) were distinguished. In both sectors PM₁₀ consists of four major source categories: 35% secondary, 20% industrial, 17% soil and 16% soot in the urban background sector compared to 45% industrial, 20% secondary, 13% soil, and 9% soot in the industrial sector. As the secondary and the soot components are higher in the urban background sector than in the industrial sector, it is concluded that both components predominantly originate from urban background sources (traffic, coal burning, and domestic heating). Abatement measures should not only focus on the steel work but should also include the urban background aerosol. PMID:23149950

  18. Organic aerosol components derived from 25 AMS datasets across Europe using a newly developed ME-2 based source apportionment strategy

    NASA Astrophysics Data System (ADS)

    Crippa, M.; Canonaco, F.; Lanz, V. A.; Äijälä, M.; Allan, J. D.; Carbone, S.; Capes, G.; Dall'Osto, M.; Day, D. A.; DeCarlo, P. F.; Di Marco, C. F.; Ehn, M.; Eriksson, A.; Freney, E.; Hildebrandt Ruiz, L.; Hillamo, R.; Jimenez, J.-L.; Junninen, H.; Kiendler-Scharr, A.; Kortelainen, A.-M.; Kulmala, M.; Mensah, A. A.; Mohr, C.; Nemitz, E.; O'Dowd, C.; Ovadnevaite, J.; Pandis, S. N.; Petäjä, T.; Poulain, L.; Saarikoski, S.; Sellegri, K.; Swietlicki, E.; Tiitta, P.; Worsnop, D. R.; Baltensperger, U.; Prévôt, A. S. H.

    2013-09-01

    Organic aerosols (OA) represent one of the major constituents of submicron particulate matter (PM1) and comprise a huge variety of compounds emitted by different sources. Three intensive measurement field campaigns to investigate the aerosol chemical composition all over Europe were carried out within the framework of EUCAARI and the intensive campaigns of EMEP during 2008 (May-June and September-October) and 2009 (February-March). In this paper we focus on the identification of the main organic aerosol sources and we propose a standardized methodology to perform source apportionment using positive matrix factorization (PMF) with the multilinear engine (ME-2) on Aerodyne aerosol mass spectrometer (AMS) data. Our source apportionment procedure is tested and applied on 25 datasets accounting for urban, rural, remote and high altitude sites and therefore it is likely suitable for the treatment of AMS-related ambient datasets. For most of the sites, four organic components are retrieved, improving significantly previous source apportionment results where only a separation in primary and secondary OA sources was possible. Our solutions include two primary OA sources, i.e. hydrocarbon-like OA (HOA) and biomass burning OA (BBOA) and two secondary OA components, i.e. semi-volatile oxygenated OA (SV-OOA) and low-volatility oxygenated OA (LV-OOA). For specific sites cooking-related (COA) and marine-related sources (MSA) are also separated. Finally, our work provides a large overview of organic aerosol sources in Europe and an interesting set of highly time resolved data for modeling evaluation purposes.

  19. Assessment of source apportionment by Positive Matrix Factorization analysis on fine and coarse urban aerosol size fractions

    NASA Astrophysics Data System (ADS)

    Karanasiou, A. A.; Siskos, P. A.; Eleftheriadis, K.

    This study was conducted in order to investigate the differences observed in source profiles in the urban environment, when chemical composition parameters from different aerosol size fractions are subjected to factor analysis. Source apportionment was performed in an urban area where representative types of emission sources are present. PM 10 and PM 2 samples were collected within the Athens Metropolitan area and analysed for trace elements, inorganic ions and black carbon. Analysis by two-way and three-way Positive Matrix Factorization was performed, in order to resolve sources from data obtained for the fine and coarse aerosol fractions. A difference was observed: seven factors describe the best solution in PMF3 while six factors in PMF2. Six factors derived from PMF3 analysis correspond to those described by the PMF2 solution for the fine and coarse particles separately. These sources were attributed to road dust, marine aerosol, soil, motor vehicles, biomass burning, and oil combustion. The additional source resolved by PMF3 was attributed to a different type of road dust. Combustion sources (oil combustion and biomass burning) were correctly attributed by PMF3 solely to the fine fraction and the soil source to the coarse fraction. However, a motor vehicle's contribution to the coarse fraction was found only by three-way PMF. When PMF2 was employed in PM 10 concentrations the optimum solution included six factors. Four source profiles corresponded to the previously identified as vehicles, road dust, biomass burning and marine aerosol, while two could not be clearly identified. Source apportionment by PMF2 analysis based solely on PM 10 aerosol composition data, yielded unclear results, compared to results from PMF2 and PMF3 analyses on fine and coarse aerosol composition data.

  20. Source apportionment of organic aerosol across Houston, TX during DISCOVER-AQ

    NASA Astrophysics Data System (ADS)

    Yoon, S.; Clark, A. E.; Ortiz, S. M.; Usenko, S.; Sheesley, R. J.

    2015-12-01

    As part of the ground-based sampling efforts during DISCOVER-AQ's Houston month-long campaign in September 2013, atmospheric particulate matter (PM) samples were collected at four sites: Moody Tower (urban), Manvel Croix (southern suburb), Conroe (northern suburb), and La Porte (urban industrial). The Houston metropolitan area, especially the Houston Ship Channel, is a densely industrialized urban city with large concentrations of petroleum refining, petrochemical manufacturing, and heavy traffic during peak hours. Due to these and other emission sources, the area is heavily impacted by ambient PM. This study will be looking at fine PM (diameter less than 2.5µm, PM2.5) from all four sites. PM2.5fraction is relevant for understanding fate and transport of organic contaminants and is widely known to negatively impact human health. Chemical analysis including radiocarbon (14C) and organic tracer measurements (polycyclic aromatic hydrocarbons, alkanes, hopanes, steranes, and levoglucosan) were used for source apportionment. The 14C measurements constrained CMB results to estimate both primary and secondary contributions to total organic carbon (TOC). Results indicate that Moody Tower had consistent primary motor vehicle exhaust contribution (18-27%) and a fossil secondary organic aerosol (SOA) contribution from 5-33% depending on atmospheric conditions. Conroe had a lower contribution of motor vehicle exhaust (5-10%) and similarly variable fraction of fossil SOA (4-25%). Manvel Croix had an interim motor vehicle contribution (9-15%) with a variable fossil SOA (5-30%). For contemporary OC, there was minimal contribution of wood smoke during examined weeks (0-9%) but larger contributor of biogenic SOA ranging from 40-75% at Moody Tower, 56-81% at Manvel Croix and 60-79% at Conroe. Overall, the motor vehicle contribution was consistent at each site during the analysis week, biogenic SOA was consistently high, while fossil SOA showed the most variability.

  1. Lead Isotopic Composition and Trace Metals in Aerosols for Source Apportionment

    NASA Astrophysics Data System (ADS)

    Chien, C. T.; Paytan, A.

    2014-12-01

    Transported thousands of miles away from their source, aerosols can be dispersed and deposition throughout the Earth's surface. Aerosols from natural and industrial sources have different characteristics and health impacts thus it is important to identify their sources. The lead isotopic composition and trace metals in aerosol samples collected in different regions and periods around the world can help us better understand spatial and seasonal variation of aerosol sources. Aerosol samples collected in California, Bermuda, China and the Red Sea have been analyzed. The trace metal and Pb isotopes in these samples provide information regarding the various sources of aerosols to these sites.

  2. Organic composition and source apportionment of fine aerosol at Monterrey, Mexico, based on organic markers

    NASA Astrophysics Data System (ADS)

    Mancilla, Y.; Mendoza, A.; Fraser, M. P.; Herckes, P.

    2016-01-01

    attribution results obtained using the CMB (chemical mass balance) model indicate that emissions from motor vehicle exhausts are the most important, accounting for the 64 % of the PM2.5, followed by meat-cooking operations with 31 % The vegetative detritus and biomass burning had the smallest contribution (2.2 % of the PM2.5). To our knowledge, this is only the second study to explore the organic composition and source apportionment of fine organic aerosol based on molecular markers in Mexico and the first for the MMA. Particularly molecular marker were quantified by solvent extraction with dichloromethane, derivatization, and gas chromatography with mass spectrometry (GC/MS).

  3. Characterization of emissions from South Asian biofuels and application to source apportionment of carbonaceous aerosol in the Himalayas

    NASA Astrophysics Data System (ADS)

    Stone, Elizabeth A.; Schauer, James J.; Pradhan, Bidya Banmali; Dangol, Pradeep Man; Habib, Gazala; Venkataraman, Chandra; Ramanathan, V.

    2010-03-01

    This study focuses on improving source apportionment of carbonaceous aerosol in South Asia and consists of three parts: (1) development of novel molecular marker-based profiles for real-world biofuel combustion, (2) application of these profiles to a year-long data set, and (3) evaluation of profiles by an in-depth sensitivity analysis. Emissions profiles for biomass fuels were developed through source testing of a residential stove commonly used in South Asia. Wood fuels were combusted at high and low rates, which corresponded to source profiles high in organic carbon (OC) or high in elemental carbon (EC), respectively. Crop wastes common to the region, including rice straw, mustard stalk, jute stalk, soybean stalk, and animal residue burnings, were also characterized. Biofuel profiles were used in a source apportionment study of OC and EC in Godavari, Nepal. This site is located in the foothills of the Himalayas and was selected for its well-mixed and regionally impacted air masses. At Godavari, daily samples of fine particulate matter (PM2.5) were collected throughout the year of 2006, and the annual trends in particulate mass, OC, and EC followed the occurrence of a regional haze in South Asia. Maximum concentrations occurred during the dry winter season and minimum concentrations occurred during the summer monsoon season. Specific organic compounds unique to aerosol sources, molecular markers, were measured in monthly composite samples. These markers implicated motor vehicles, coal combustion, biomass burning, cow dung burning, vegetative detritus, and secondary organic aerosol as sources of carbonaceous aerosol. A molecular marker-based chemical mass balance (CMB) model provided a quantitative assessment of primary source contributions to carbonaceous aerosol. The new profiles were compared to widely used biomass burning profiles from the literature in a sensitivity analysis. This analysis indicated a high degree of stability in estimates of source

  4. Studying organic aerosols during bonfire night in Manchester: ME-2 source apportionment

    NASA Astrophysics Data System (ADS)

    Reyes Villegas, Ernesto; Allan, James

    2016-04-01

    Over the past decade, there has been an increasing interest in short-term events that negatively affect air quality (Zhao et al. 2014) such as bonfires and fireworks. In general, during these episodes, high particulate matter concentrations drop within 24 hrs; however, it is the fine fraction that dominates the emissions, known to have a potentially negative impact on air quality, thus the impact of bonfires/fireworks on air quality must be considered. Aerosols and gases were measured using a variety of instruments at The University of Manchester, sampling atmospheric emissions on Bonfire night, 5 November, one week before and one week later, in 2013 and 2014. The Multilinear Engine (ME-2) factorization tool was used through the recently developed source finder interface (SoFi, Canonaco et al. 2013) to identify sources of organic aerosols (OA) sampled with an Aerosol Mass Spectrometer (AMS). ME-2 identified five sources: solid fuel OA (SFOA), hydrocarbon like OA (HOA), cooking OA (COA), semi-volatile (SVOOA) and low volatility (LVOOA) during both years. In 2014, air pollutant concentrations were particularly high, with the highest SFOA concentrations being 20 μgm-3 at 20:30 hrs. when fireworks from different parks in Manchester were launched. Black carbon (BC) concentrations started increasing before the fireworks, around 18:00 hrs; these concentrations are representative of bonfire emissions. However, traffic emissions may be contributing to BC here; further work will be done to differentiate traffic emissions from solid fuel emissions. By analysing daily aerosol concentrations according to DEFRA's Daily Air Quality Index, it is possible to observe that in 2014, PM2.5 concentrations were considered to be high (65 μgm-3) while in 2013, PM2.5 concentrations were considered low (12 μgm-3); in the case of BBOA, concentrations ranged from 2.9 μgm-3 in 2014 to 0.65 μgm-3 in 2013. The discrepancy between these studies is mainly a result of different meteorological

  5. Composition and source apportionment of surfactants in atmospheric aerosols of urban and semi-urban areas in Malaysia.

    PubMed

    Wahid, Nurul Bahiyah Abd; Latif, Mohd Talib; Suratman, Suhaimi

    2013-06-01

    This study was conducted to determine the composition and source apportionment of surfactant in atmospheric aerosols around urban and semi-urban areas in Malaysia based on ionic compositions. Colorimetric analysis was undertaken to determine the concentrations of anionic surfactants as Methylene Blue Active Substances (MBAS) and cationic surfactants as Disulphine Blue Active Substances (DBAS) using a UV spectrophotometer. Ionic compositions were determined using ion chromatography for cations (Na(+), NH4(+), K(+), Mg(2+), Ca(2+)) and anions (F(-), Cl(-), NO3(-), SO4(2-)). Principle component analysis (PCA) combined with multiple linear regression (MLR) were used to identify the source apportionment of MBAS and DBAS. Results indicated that the concentrations of surfactants at both sampling sites were dominated by MBAS rather than DBAS especially in fine mode aerosols during the southwest monsoon. Three main sources of surfactants were identified from PCA-MLR analysis for MBAS in fine mode samples particularly in Kuala Lumpur, dominated by motor vehicles, followed by soil/road dust and sea spray. Besides, for MBAS in coarse mode, biomass burning/sea spray were the dominant source followed by motor vehicles/road dust and building material. PMID:23336924

  6. Source apportionment of absorbing aerosols in the central Indo-Gangetic Plain

    NASA Astrophysics Data System (ADS)

    Vaishya, Aditya; Singh, Prayagraj; Rastogi, Shantanu; Babu, S. Suresh

    2016-05-01

    Atmospheric aerosols in the Indo-Gangetic Plain (IGP) depicts high spatial and temporal heterogeneity in their radiative properties. Despite the fact that significant advancement in terms of characterizing aerosols radiative and physiochemical properties in the IGP have been made, information regarding the organic content towards total absorbing aerosol budget is lacking. In the present study we have analyzed two years of aerosol spectral light absorption measurements from the central-IGP, Gorakhpur (26.75°N, 83.38°E, 85m amsl), in order to study their seasonal behavior and to quantify their magnitude in terms of absorbing aerosols loading and source speciation. Remote sensing data in the form of 'Cloud corrected Fire Count' from MODIS Terra and 'Absorption Aerosol Index' from OMI satellites platform have been used to identify absorbing aerosol source regions. Spectral absorption analysis reveals a four-fold enhancement in absorption in the winter (W) and the post-monsoon (PoM) seasons at UV wavelengths as compared to 880 nm on account of increased biomass aerosol contribution to total absorbing aerosol load. Despite having higher fire events and absorption aerosol index, both indicating high biomass burning activities, in the pre-monsoon (PM) season, aerosols from the biomass sources contribute ~ 27% during the W and the PoM seasons as against ~17% in the PM season to the total absorbing aerosol content. This is due to near stagnant wind conditions and shallow height of air masses travelling to the central IGP in the W and the PoM seasons.

  7. Apportionment of urban aerosol sources in Cork (Ireland) by synergistic measurement techniques.

    PubMed

    Dall'Osto, Manuel; Hellebust, Stig; Healy, Robert M; O'Connor, Ian P; Kourtchev, Ivan; Sodeau, John R; Ovadnevaite, Jurgita; Ceburnis, Darius; O'Dowd, Colin D; Wenger, John C

    2014-09-15

    The sources of ambient fine particulate matter (PM2.5) during wintertime at a background urban location in Cork city (Ireland) have been determined. Aerosol chemical analyses were performed by multiple techniques including on-line high resolution aerosol time-of-flight mass spectrometry (Aerodyne HR-ToF-AMS), on-line single particle aerosol time-of-flight mass spectrometry (TSI ATOFMS), on-line elemental carbon-organic carbon analysis (Sunset_EC-OC), and off-line gas chromatography/mass spectrometry and ion chromatography analysis of filter samples collected at 6-h resolution. Positive matrix factorization (PMF) has been carried out to better elucidate aerosol sources not clearly identified when analyzing results from individual aerosol techniques on their own. Two datasets have been considered: on-line measurements averaged over 2-h periods, and both on-line and off-line measurements averaged over 6-h periods. Five aerosol sources were identified by PMF in both datasets, with excellent agreement between the two solutions: (1) regional domestic solid fuel burning--"DSF_Regional," 24-27%; (2) local urban domestic solid fuel burning--"DSF_Urban," 22-23%; (3) road vehicle emissions--"Traffic," 15-20%; (4) secondary aerosols from regional anthropogenic sources--"SA_Regional" 9-13%; and (5) secondary aged/processed aerosols related to urban anthropogenic sources--"SA_Urban," 21-26%. The results indicate that, despite regulations for restricting the use of smoky fuels, solid fuel burning is the major source (46-50%) of PM2.5 in wintertime in Cork, and also likely other areas of Ireland. Whilst wood combustion is strongly associated with OC and EC, it was found that peat and coal combustion is linked mainly with OC and the aerosol from these latter sources appears to be more volatile than that produced by wood combustion. Ship emissions from the nearby port were found to be mixed with the SA_Regional factor. The PMF analysis allowed us to link the AMS cooking organic

  8. Apportionment of urban aerosol sources in Chongqing (China) using synergistic on-line techniques

    NASA Astrophysics Data System (ADS)

    Chen, Yang; Yang, Fumo

    2016-04-01

    The sources of ambient fine particulate matter (PM2.5) during wintertime at a background urban location in Chongqing (southwestern China) have been determined. Aerosol chemical composition analyses were performed using multiple on-line techniques, such as single particle aerosol mass spectrometer (SPAMS) for single particle chemical composition, on-line elemental carbon-organic carbon analyzer (on-line OC-EC), on-line X-ray fluorescence (XRF) for elements, and in-situ Gas and Aerosol Compositions monitor (IGAC) for water-soluble ions in PM2.5. All the datasets from these techniques have been adjusted to a 1-h time resolution for receptor model input. Positive matrix factorization (PMF) has been used for resolving aerosol sources. At least six sources, including domestic coal burning, biomass burning, dust, traffic, industrial and secondary/aged factors have been resolved and interpreted. The synergistic on-line techniques were helpful for identifying aerosol sources more clearly than when only employing the results from the individual techniques. This results are useful for better understanding of aerosol sources and atmospheric processes.

  9. SOURCE APPORTIONMENT OF PHOENIX PM2.5 AEROSOL WITH THE UNMIX RECEPTOR MODEL

    EPA Science Inventory

    The multivariate receptor model Unmix has been used to analyze a 3-yr PM2.5 ambient aerosol data set collected in Phoenix, AZ, beginning in 1995. The analysis generated source profiles and overall percentage source contribution estimates (SCE) for five source categories: ga...

  10. A long term source apportionment study of wood burning and traffic aerosols for three measurement sites in Switzerland

    NASA Astrophysics Data System (ADS)

    Herich, Hanna; Hüglin, Christoph; Buchmann, Brigitte

    2010-05-01

    Besides their effects on radiative forcing soot aerosols have been found to cause health effects as they are carcinogenic. Diesel engines and incomplete biomass burning are the major emission sources of soot particles. Especially during winter, the wood burning (WB) emissions from residential heating have been found to contribute significantly to the total carbonaceous material (CM). To investigate the contribution of fossil fuel (FF) and WB emissions seven-wavelength aethalometers have been deployed in previous studies (Sandradewi et al. 2008, Favez et al. 2009). In these studies, the stronger light absorption of WB aerosols in the blue and ultraviolet compared to the light absorption of aerosols from FF combustion was used. Linear regression modelling of CM against the light absorption coefficient of FF combustion aerosols in the infrared (950 nm) and the light absorption coefficient of WB aerosols in the blue (470 nm) was proposed for source apportionment. In this study we present long term aethalometer measurements at two rural and one urban background measurement stations in Switzerland from 2008 - 2010. At these stations organic (OC) and elemental carbon (EC) were also measured by thermochemical analysis providing estimates for total CM. Above described linear regession modelling was applied for determination of the contribution of FF and WB emissions to total CM. Sensitivity tests for different regression models and for varying light absorption exponents were performed. It was found that the regression modelling approach is only limited suitable for long term datasets because of significant fractions of CM resulting from sources and processes other than FF and WB. Thus in a different approach we focused on black carbon (BC). The contribution of WB and FF to BC was directly determined from the absorption coefficients of FF and WB aerosols which were calculated with the use of absorption exponents taken from literature. First results show that in winter the

  11. CARBON CONTAINING COMPONENT OF THE LOS ANGELES AEROSOL: SOURCE APPORTIONMENT AND CONTRIBUTIONS TO THE VISIBILITY BUDGET

    EPA Science Inventory

    Source resolution of the organic component of the fine fraction of the ambient aerosol (d(sub p) < 3.5 micrometers) has been carried out by combining source information from the organic component with thermal analysis and local emission inventories. The primary and secondary carb...

  12. The AIRPARIF-AEROSOL project: A comprehensive source apportionment study of fine aerosols (PM2.5) in the region of Paris (France)

    NASA Astrophysics Data System (ADS)

    Sciare, Jean; Ghersi, Veronique; Bressi, Michael; Lameloise, Philippe; Bonnaire, Nicolas; Rosso, Amandine; Nicolas, Jose; Moukhtar, Sophie; Ferron, Anais; Baumier, Dominique

    2010-05-01

    With a population of about 12 millions inhabitants (20% of the French population), Greater Paris (France) is one of the most populated megacity in Europe and among the few located in developed countries. Due to its favorable geographical situation (far from other big European cities and influenced very often by clean oceanic air masses), it may be considered as a good candidate for investigating the build-up of urban air pollution from temperate industrialized countries. Particulate mass of fine aerosols with aerodynamic diameter below 2.5μm (PM2.5) is continuously monitored at several stations from great Paris for almost 8 years by the local air quality network (AIRPARIF), using a conventional on-line automatic system (R&P TEOM; see Patashnik and Rupprecht, 1991). During the period 2000-2006, levels of PM2.5 in the region of Paris have shown rather stable yearly mean values ranging 13 to 16?g/m3 whereas most of the other pollutants monitored by AIRPARIF have shown a net decrease during this period (http:\\www.airparif.asso.fr). Since the year 2007, this situation has becoming worse for particulate pollution with a net increase of the yearly mean concentration of PM2.5 (up to 21?g/m3), which increase is partly due to the use of a new PM2.5 measurement technique (R&P TEOM-FDMS instrument) enabling a proper determination of the semi-volatile fraction of fine aerosols. Although this new method greatly improves the determination of PM2.5, it has also brought PM2.5 levels in the region of Paris closer to the 25?g/m3 yearly mean targeted value recommended by Europe for 2010 (limit value for 2015). Efficient abatement policies aiming at reducing levels of PM2.5 in the region of Paris will have to be fed by preliminary PM2.5 source apportionment studies and exhaustive aerosol chemistry studies (chemical mass balance) allowing a better separation between regional to continental aerosol sources. The objective of the AIRPARIF-AEROSOL project aims to perform a spatially- and

  13. Nuclear microprobe analysis and source apportionment of individual atmospheric aerosol particles

    NASA Astrophysics Data System (ADS)

    Artaxo, Paulo; Rabello, Marta L. C.; Watt, Frank; Grime, Geoff; Swietlicki, Erik

    1993-04-01

    In atmospheric aerosol research, one key issue is to determine the sources of the airborne particles. Bulk PIXE analysis coupled with receptor modeling provides a useful, but limited view of the aerosol sources influencing one particular site or sample. The scanning nuclear microprobe (SNM) technique is a microanalytical technique that gives unique information on individual aerosol particles. In the SNM analyses a 1.0 μm size 2.4 MeV proton beam from the Oxford SNM was used. The trace elements with Z > 11 were measured by the particle induced X-ray emission (PIXE) method with detection limits in the 1-10 ppm range. Carbon, nitrogen and oxygen are measured simultaneously using Rutherford backscattering spectrometry (RBS). Atmospheric aerosol particles were collected at the Brazilian Antarctic Station and at biomass burning sites in the Amazon basin tropical rain forest in Brazil. In the Antarctic samples, the sea-salt aerosol particles were clearly predominating, with NaCl and CaSO 4 as major compounds with several trace elements as Al, Si, P, K, Mn, Fe, Ni, Cu, Zn, Br, Sr, and Pb. Factor analysis of the elemental data showed the presence of four components: 1) soil dust particles; 2) NaCl particles; 3) CaSO 4 with Sr; and 4) Br and Mg. Strontium, observed at 20-100 ppm levels, was always present in the CaSO 4 particles. The hierarchical cluster procedure gave results similar to the ones obtained through factor analysis. For the tropical rain forest biomass burning aerosol emissions, biogenic particles with a high organic content dominate the particle population, while K, P, Ca, Mg, Zn, and Si are the dominant elements. Zinc at 10-200 ppm is present in biogenic particles rich in P and K. The quantitative aspects and excellent detection limits make SNM analysis of individual aerosol particles a very powerful analytical tool.

  14. Isotope-Based Source Apportionment of EC Aerosol Particles during Winter High-Pollution Events at the Zeppelin Observatory, Svalbard.

    PubMed

    Winiger, Patrik; Andersson, August; Yttri, Karl E; Tunved, Peter; Gustafsson, Örjan

    2015-10-01

    Black carbon (BC) aerosol particles contribute to climate warming of the Arctic, yet both the sources and the source-related effects are currently poorly constrained. Bottom-up emission inventory (EI) approaches are challenged for BC in general and the Arctic in particular. For example, estimates from three different EI models on the fractional contribution to BC from biomass burning (north of 60° N) vary between 11% and 68%, each acknowledging large uncertainties. Here we present the first dual-carbon isotope-based (Δ(14)C and δ(13)C) source apportionment of elemental carbon (EC), the mass-based correspondent to optically defined BC, in the Arctic atmosphere. It targeted 14 high-loading and high-pollution events during January through March of 2009 at the Zeppelin Observatory (79° N; Svalbard, Norway), with these representing one-third of the total sampling period that was yet responsible for three-quarters of the total EC loading. The top-down source-diagnostic (14)C fingerprint constrained that 52 ± 15% (n = 12) of the EC stemmed from biomass burning. Including also two samples with 95% and 98% biomass contribution yield 57 ± 21% of EC from biomass burning. Significant variability in the stable carbon isotope signature indicated temporally shifting emissions between different fossil sources, likely including liquid fossil and gas flaring. Improved source constraints of Arctic BC both aids better understanding of effects and guides policy actions to mitigate emissions. PMID:26332725

  15. Online coupling of pure O2 thermo-optical methods - 14C AMS for source apportionment of carbonaceous aerosols

    NASA Astrophysics Data System (ADS)

    Agrios, Konstantinos; Salazar, Gary; Zhang, Yan-Lin; Uglietti, Chiara; Battaglia, Michael; Luginbühl, Marc; Ciobanu, Viorela Gabriela; Vonwiller, Matthias; Szidat, Sönke

    2015-10-01

    This paper reports on novel separation methods developed for the direct determination of 14C in organic carbon (OC) and elemental carbon (EC), two sub-fractions of total carbon (TC) of atmospheric air particulate matter. Until recently, separation of OC and EC has been performed off-line by manual and time-consuming techniques that relied on the collection of massive CO2 fractions. We present here two on-line hyphenated techniques between a Sunset OC/EC analyzer and a MICADAS (MIni radioCArbon DAting System) accelerator mass spectrometer (AMS) equipped with a gas ion source. The first implementation facilitates the direct measurement in the low sample size range (<10 μg C) with high throughput on a routine basis, while the second explores the potential for a continuous-flow real-time CO2 gas feed into the ion source. The performance achieved with reference materials and real atmospheric samples will be discussed to draw conclusions on the improvement offered in the field of 14C aerosol source apportionment.

  16. Source apportionment of elevated BaP concentrations in PM10 aerosols in an alpine valley in Austria

    NASA Astrophysics Data System (ADS)

    Bauer, Heidi; Puxbaum, Hans; Jankowski, Nicole; Sampaio Cordeiro Wagner, Lylian

    2010-05-01

    INTRODUCTION: In a village situated at 1215 m a.s.l. in a natural preserve in an Austrian alpine valley elevated BaP concentrations have been measured in the last years. A highly frequented highway leading from Italy to Germany passes near the village. Monthly means of particulate BaP concentrations show a clear seasonal trend with values below 1 ng/m³ during the warmer months and with concentrations up to 9 ng/m³ in the cold season. Annual averages in the years 2000 - 2005 ranged between 1.4 and 2.8 ng/m³ - much higher than the EU target value of 1 ng/m³. We used a macrotracer model developed at the Vienna University of Technology to determine the contributions of the sources for BaP emissions, which were mainly space heating with wood and traffic from the highway. EXPERIMENTAL: The macrotracer concept is a nine component model to derive source contribution and explains 80-100% of PM10 aerosols in Austria. The amount of traffic exhaust is derived by using EC as tracer, whereas EC produced by wood burning is subtracted, the amount of wood smoke is derived by the anhydro-sugar levoglucosan and the ratio between the anhydro-sugars levoglucosan and mannosan. For the source apportionment of BaP the applied factors reflect on the one hand the composition of the automotive fleet in Austria and on the other hand the composition of the fire wood in the region. Filter samples collected with a high volume sampler in winter were analyzed for PM10 aerosol mass, total, organic, elemental and carbonate carbon, HULIS, anhydro-sugars, polyols and ions (major ions and organic acids) and PAHs. In the same way emission samples taken at a motor test stand and at a test stand for wood combustion were analyzed (Schmidl et al. 2008). The saccharides were determined using high pH anion exchange and pulsed amperometry (HPAE-PAD). Details of the analytical method are given in Iinuma et al., 2009. Elemental and organic carbon were determined with a thermal-optical instrument (Sunset lab

  17. Characterization and source apportionment of submicron aerosol with aerosol mass spectrometer during the PRIDE-PRD 2006 campaign

    NASA Astrophysics Data System (ADS)

    Xiao, R.; Takegawa, N.; Zheng, M.; Kondo, Y.; Miyazaki, Y.; Miyakawa, T.; Hu, M.; Shao, M.; Zeng, L.; Gong, Y.; Lu, K.; Deng, Z.; Zhao, Y.; Zhang, Y. H.

    2011-01-01

    Size-resolved chemical compositions of non-refractory submicron aerosol were measured using an Aerodyne quadrupole aerosol mass spectrometer (Q-AMS) at the rural site Back Garden (BG), located ~50 km northwest of Guangzhou in July 2006. This paper characterized the submicron aerosol particles of regional air pollution in Pearl River Delta (PRD) in the Southern China. Organics and sulfate dominated the submicron aerosol compositions, with average mass concentrations of 11.8±8.4 μg m-3 and 13.5±8.7 μg m-3, respectively. Unlike other air masses, the air masses originated from Southeast-South and passing through the PRD urban areas exhibited distinct bimodal size distribution characteristics for both organics and sulfate: the first mode peaked at vacuum aerodynamic diameters (Dva)~200 nm and the second mode occurred at Dva from 300-700 nm. With the information from AMS, it was found from this study that the first mode of organics in PRD regional air masses was contributed by both secondary organic aerosol formation and combustion-related emissions, which is different from most findings in other urban areas (first mode of organics primarily from combustion-related emissions). The analysis of AMS mass spectra data by positive matrix factorization (PMF) model identified three sources of submicron organic aerosol including hydrocarbon-like organic aerosol (HOA), low volatility oxygenated organic aerosol (LV-OOA) and semi-volatile oxygenated organic aerosol (SV-OOA). The strong correlation between HOA and EC indicated primary combustion emissions as the major source of HOA while a close correlation between SV-OOA and semi-volatile secondary species nitrate as well as between LV-OOA and nonvolatile secondary species sulfate suggested secondary aerosol formation as the major source of SV-OOA and LV-OOA at the BG site. However, LV-OOA was more aged than SV-OOA as its spectra was highly correlated with the reference spectra of fulvic acid, an indicator of aged and

  18. Characterization and source apportionment of submicron aerosol with aerosol mass spectrometer during the PRIDE-PRD 2006 campaign

    NASA Astrophysics Data System (ADS)

    Xiao, R.; Takegawa, N.; Zheng, M.; Kondo, Y.; Miyazaki, Y.; Miyakawa, T.; Hu, M.; Shao, M.; Zeng, L.; Gong, Y.; Lu, K.; Deng, Z.; Zhao, Y.; Zhang, Y. H.

    2011-07-01

    Size-resolved chemical compositions of non-refractory submicron aerosol were measured using an Aerodyne quadrupole aerosol mass spectrometer (Q-AMS) at the rural site Back Garden (BG), located ~50 km northwest of Guangzhou in July 2006. This paper characterized the submicron aerosol particles of regional air pollution in Pearl River Delta (PRD) in the southern China. Organics and sulfate dominated the submicron aerosol compositions, with average mass concentrations of 11.8 ± 8.4 μg m-3 and 13.5 ± 8.7 μg m-3, respectively. Unlike other air masses, the air masses originated from Southeast-South and passing through the PRD urban areas exhibited distinct bimodal size distribution characteristics for both organics and sulfate: the first mode peaked at vacuum aerodynamic diameters (Dva) ∼200 nm and the second mode occurred at Dva from 300-700 nm. With the information from AMS, it was found from this study that the first mode of organics in PRD regional air masses was contributed by both secondary organic aerosol formation and combustion-related emissions, which is different from most findings in other urban areas (first mode of organics primarily from combustion-related emissions). The analysis of AMS mass spectra data by positive matrix factorization (PMF) model identified three sources of submicron organic aerosol including hydrocarbon-like organic aerosol (HOA), low volatility oxygenated organic aerosol (LV-OOA) and semi-volatile oxygenated organic aerosol (SV-OOA). The strong correlation between HOA and EC indicated primary combustion emissions as the major source of HOA while a close correlation between SV-OOA and semi-volatile secondary species nitrate as well as between LV-OOA and nonvolatile secondary species sulfate suggested secondary aerosol formation as the major source of SV-OOA and LV-OOA at the BG site. However, LV-OOA was more aged than SV-OOA as its spectra was highly correlated with the reference spectra of fulvic acid, an indicator of aged and

  19. Source apportionment of molecular markers and organic aerosol--1. Polycyclic aromatic hydrocarbons and methodology for data visualization.

    PubMed

    Robinson, Allen L; Subramanian, R; Donahue, Neil M; Bernardo-Bricker, Anna; Rogge, Wolfgang F

    2006-12-15

    Individual organic compounds often referred to as molecular markers are used in conjunction with the chemical mass balance (CMB) model to apportion sources of primary organic aerosol. This paper presents a methodology to visualize molecular marker data; it allows comparison of ambient data and source profiles and allows assessment of chemical stability and aging. The method is intended to complement traditional quantitative source apportionment analysis. The core of the technique involves construction of plots of ratios of species concentrations (ratio-ratio plots) in which source profiles appear as points connected by linear mixing lines. The approach is illustrated using data collected over a 1-year period in Pittsburgh, Pennsylvania. The analysis considers for elemental carbon and a number of high molecular weight polycyclic aromatic hydrocarbons (PAHs) commonly used as molecular markers in CMB: benzo(b+j+k)fluoranthene, benzo(e)pyrene, benzo[g,h,i]perylene, coronene, and indeno(1,2,3-cd)pyrene. In Pittsburgh, the ambient concentrations of these PAHs are higher than in other cities in the United States; they are also strongly correlated consistent with a single, dominant source. Both ratio-ratio plots and CMB analysis indicate that this source is metallurgical coke production. Although emissions from coke production dominate ambient PAH concentrations, on most study days they contributed little fine particle mass. Ratio-ratio plots are then used to investigate the feasibility of using PAHs to help differentiate between gasoline and diesel vehicle emissions. Ambient concentrations of these large PAHs provide little information on the gasoline-diesel split because of the strong influence of local emissions from coke production combined with evidence of photochemical decay of PAHs in the regional air mass. Decay of PAHs will bias estimates of the gasoline-diesel split toward diesel emissions. PMID:17256531

  20. Carbonaceous aerosols and pollutants over Delhi urban environment: Temporal evolution, source apportionment and radiative forcing.

    PubMed

    Bisht, D S; Dumka, U C; Kaskaoutis, D G; Pipal, A S; Srivastava, A K; Soni, V K; Attri, S D; Sateesh, M; Tiwari, S

    2015-07-15

    Particulate matter (PM2.5) samples were collected over Delhi, India during January to December 2012 and analysed for carbonaceous aerosols and inorganic ions (SO4(2-) and NO3(-)) in order to examine variations in atmospheric chemistry, combustion sources and influence of long-range transport. The PM2.5 samples are measured (offline) via medium volume air samplers and analysed gravimetrically for carbonaceous (organic carbon, OC; elemental carbon, EC) aerosols and inorganic ions (SO4(2-) and NO3(-)). Furthermore, continuous (online) measurements of PM2.5 (via Beta-attenuation analyser), black carbon (BC) mass concentration (via Magee scientific Aethalometer) and carbon monoxide (via CO-analyser) are carried out. PM2.5 (online) range from 18.2 to 500.6μgm(-3) (annual mean of 124.6±87.9μgm(-3)) exhibiting higher night-time (129.4μgm(-3)) than daytime (103.8μgm(-3)) concentrations. The online concentrations are 38% and 28% lower than the offline during night and day, respectively. In general, larger night-time concentrations are found for the BC, OC, NO3(-)and SO4(2-), which are seasonally dependent with larger differences during late post-monsoon and winter. The high correlation (R(2)=0.74) between OC and EC along with the OC/EC of 7.09 (day time) and 4.55 (night-time), suggest significant influence of biomass-burning emissions (burning of wood and agricultural waste) as well as secondary organic aerosol formation during daytime. Concentrated weighted trajectory (CWT) analysis reveals that the potential sources for the carbonaceous aerosols and pollutants are local emissions within the urban environment and transported smoke from agricultural burning in northwest India during post-monsoon. BC radiative forcing estimates result in very high atmospheric heating rates (~1.8-2.0Kday(-1)) due to agricultural burning effects during the 2012 post-monsoon season. PMID:25864155

  1. Size distribution, mixing state and source apportionments of black carbon aerosols in London during winter time

    NASA Astrophysics Data System (ADS)

    Liu, D.; Allan, J. D.; Young, D. E.; Coe, H.; Beddows, D.; Fleming, Z. L.; Flynn, M. J.; Gallagher, M. W.; Harrison, R. M.; Lee, J.; Prevot, A. S. H.; Taylor, J. W.; Yin, J.; Williams, P. I.; Zotter, P.

    2014-06-01

    Black carbon aerosols (BC) at a London urban site were characterized in both winter and summer time 2012 during the Clean Air for London (ClearfLo) project. Positive matrix factorization (PMF) factors of organic aerosol mass spectra measured by a high resolution aerosol mass spectrometer (HR-AMS) showed traffic-dominant sources in summer but in winter the influence of additional non-traffic sources became more important, mainly from solid fuel sources (SF). Measurements using a single particle soot photometer (SP2, DMT), showed the traffic-dominant BC exhibited an almost uniform BC core size (Dc) distribution with very thin coating thickness throughout the detectable range of Dc. However the size distribution of Dc (project average mass median Dc = 149 ± 22 nm in winter, and 120 ± 6 nm in summer) and BC coating thickness varied significantly in winter. A novel methodology was developed to attribute the BC number concentrations and mass abundances from traffic (BCtr) and from SF (BCsf), by using a 2-D histogram of the particle optical properties as a function of BC core size, as measured by the SP2. The BCtr and BCsf showed distinctly different Dc distributions and coating thicknesses, with BCsf displaying larger Dc and larger coating thickness compared to BCtr. BC particles from different sources were also apportioned by applying a multiple linear regression between the total BC mass and each AMS-PMF factor (BC-AMS-PMF method), and also attributed by applying the absorption spectral dependence of carbonaceous aerosols to 7-wavelength Aethalometer measurements (Aethalometer method). Air masses that originated from westerly (W), southeasterly (SE), or easterly (E) sectors showed BCsf fractions that ranged from low to high, and whose mass median Dc values were 137 ± 10 nm, 143 ± 11 nm, and 169 ± 29 nm respectively. The corresponding bulk relative coating thickness of BC (coated particle size / BC core - Dp / Dc) for these same sectors was 1.28 ± 0.07, 1.45 ± 0

  2. Size distribution, mixing state and source apportionment of black carbon aerosol in London during wintertime

    NASA Astrophysics Data System (ADS)

    Liu, D.; Allan, J. D.; Young, D. E.; Coe, H.; Beddows, D.; Fleming, Z. L.; Flynn, M. J.; Gallagher, M. W.; Harrison, R. M.; Lee, J.; Prevot, A. S. H.; Taylor, J. W.; Yin, J.; Williams, P. I.; Zotter, P.

    2014-09-01

    Black carbon aerosols (BC) at a London urban site were characterised in both winter- and summertime 2012 during the Clean Air for London (ClearfLo) project. Positive matrix factorisation (PMF) factors of organic aerosol mass spectra measured by a high-resolution aerosol mass spectrometer (HR-AMS) showed traffic-dominant sources in summer but in winter the influence of additional non-traffic sources became more important, mainly from solid fuel sources (SF). Measurements using a single particle soot photometer (SP2, DMT), showed the traffic-dominant BC exhibited an almost uniform BC core size (Dc) distribution with very thin coating thickness throughout the detectable range of Dc. However, the size distribution of sf (project average mass median Dc = 149 ± 22 nm in winter, and 120 ± 6 nm in summer) and BC coating thickness varied significantly in winter. A novel methodology was developed to attribute the BC number concentrations and mass abundances from traffic (BCtr) and from SF (BCsf), by using a 2-D histogram of the particle optical properties as a function of BC core size, as measured by the SP2. The BCtr and BCsf showed distinctly different sf distributions and coating thicknesses, with BCsf displaying larger Dc and larger coating thickness compared to BCtr. BC particles from different sources were also apportioned by applying a multiple linear regression between the total BC mass and each AMS-PMF factor (BC-AMS-PMF method), and also attributed by applying the absorption spectral dependence of carbonaceous aerosols to 7-wavelength Aethalometer measurements (Aethalometer method). Air masses that originated from westerly (W), southeasterly (SE), and easterly (E) sectors showed BCsf fractions that ranged from low to high, and whose mass median Dc values were 137 ± 10 nm, 143 ± 11 nm and 169 ± 29 nm, respectively. The corresponding bulk relative coating thickness of BC (coated particle size/BC core - Dp/Dc) for these same sectors was 1.28 ± 0.07, 1.45 ± 0

  3. Radiocarbon-based source apportionment of elemental carbon aerosols at two South Asian receptor observatories over a full annual cycle

    NASA Astrophysics Data System (ADS)

    Budhavant, Krishnakant; Andersson, August; Bosch, Carme; Kruså, Martin; Kirillova, E. N.; Sheesley, R. J.; Safai, P. D.; Rao, P. S. P.; Gustafsson, Örjan

    2015-06-01

    Black carbon (BC) aerosols impact climate and air quality. Since BC from fossil versus biomass combustion have different optical properties and different abilities to penetrate the lungs, it is important to better understand their relative contributions in strongly affected regions such as South Asia. This study reports the first year-round 14C-based source apportionment of elemental carbon (EC), the mass-based correspondent to BC, using as regional receptor sites the international Maldives Climate Observatory in Hanimaadhoo (MCOH) and the mountaintop observatory of the Indian Institute of Tropical Meteorology in Sinhagad, India (SINH). For the highly-polluted winter season (December-March), the fractional contribution to EC from biomass burning (fbio) was 53 ± 5% (n = 6) at MCOH and 56 ± 3% at SINH (n = 5). The fbio for the non-winter remainder was 53 ± 11% (n = 6) at MCOH and 48 ± 8% (n = 7) at SINH. This observation-based constraint on near-equal contributions from biomass burning and fossil fuel combustion at both sites compare with predictions from eight technology-based emission inventory (EI) models for India of (fbio)EI spanning 55-88%, suggesting that most current EI for Indian BC systematically under predict the relative contribution of fossil fuel combustion. A continued iterative testing of bottom-up EI with top-down observational source constraints has the potential to lead to reduced uncertainties regarding EC sources and emissions to the benefit of both models of climate and air quality as well as guide efficient policies to mitigate emissions.

  4. Inter-comparison of source apportionment models for the estimation of wood burning aerosols during wintertime in an Alpine city (Grenoble, France)

    NASA Astrophysics Data System (ADS)

    Favez, O.; El Haddad, I.; Piot, C.; Boréave, A.; Abidi, E.; Marchand, N.; Jaffrezo, J.-L.; Besombes, J.-L.; Personnaz, M.-B.; Sciare, J.; Wortham, H.; George, C.; D'Anna, B.

    2010-06-01

    The emission of organic aerosols (OA) in the ambient air by residential wood burning is nowadays a subject of great scientific concern and a growing number of studies aim at apportioning the influence of such emissions on urban air quality. In the present study, results obtained using two commonly-used source apportionment models, i.e., Chemical Mass Balance (CMB, performed with off-line filter measurements) and Positive Matrix Factorization (PMF, applied to Aerosol Mass Spectrometer measurements), as well as using the recently-proposed Aethalometer model (based on the measurement of the aerosol light absorption at different wavelengths) are inter-compared. This work is performed using field data obtained during the winter season (14 to 29 January 2009) at an urban background site of a French Alpine city (Grenoble). Converging results from the different models indicate a major contribution of wood burning organic aerosols (OMwb) to the ambient aerosol organic fraction, with mean OMwb contributions to total OA of 68%, 61% and 37% for the CMB, the Aethalometer and the AMS-PMF models respectively, during the period when the three modelling studies overlapped (12 days). Quantitative discrepancies might notably be due to the overestimation of OMwb calculated by the CMB due to the loss of semi-volatile compounds from sources to receptor site, as well as to the accounting of oxidized primary wood burning organic (OPOAwb) aerosols within the Oxygenated Organic Aerosol (OOA) PMF-factor. This OOA factor accounts on average for about 50% of total OM, while non-combustion sources contribute to about 25% and 28% of total OM according to the CMB and Aethalometer models respectively. Each model suggests a mean contribution of fossil fuel emissions to total OM of about 10%. A good agreement is also obtained for the source apportionment of elemental carbon (EC) by both the CMB and the Aethalometer models, with fossil fuel emissions representing on average more than 80% of total EC.

  5. Source apportionment of submicron organic aerosol at an urban background and a road site in Barcelona (Spain) during SAPUSS

    NASA Astrophysics Data System (ADS)

    Alier, M.; van Drooge, B. L.; Dall'Osto, M.; Querol, X.; Grimalt, J. O.; Tauler, R.

    2013-10-01

    This study investigates the contribution of potential sources to the submicron (PM1) organic aerosol (OA) simultaneously detected at an urban background (UB) and a road site (RS) in Barcelona during the 30 days of the intensive field campaign of SAPUSS (Solving Aerosol Problems by Using Synergistic Strategies, September-October 2010). A total of 103 filters at 12 h sampling time resolution were collected at both sites. Thirty-six neutral and polar organic compounds of known emission sources and photo-chemical transformation processes were analyzed by gas chromatography-mass spectrometry (GC-MS). The concentrations of the trace chemical compounds analyzed are herein presented and discussed. Additionally, OA source apportionment was performed by multivariate curve resolution-alternating least squares (MCR-ALS) and six OA components were identified at both sites: two were of primary anthropogenic OA origin and three of secondary OA origin, while a sixth one was not clearly defined. Primary organics from emissions of local anthropogenic activities (urban primary organic aerosol, or POA Urban), mainly traffic emissions but also cigarette smoke, contributed 43% (1.5 μg OC m-3) and 18% (0.4 μg OC m-3) to OA at RS and UB, respectively. A secondary primary source - biomass burning (BBOA) - was found in all the samples (average values 7% RS; 12% UB; 0.3 μg OC m-3), but this component was substantially contributing to OA only when the sampling sites were under influence of regional air mass circulation (REG.). Three secondary organic aerosol (SOA) components (describing overall 60% of the variance) were observed in the urban ambient PM1. Products of isoprene oxidation (SOA ISO) - i.e. 2-methylglyceric acid, C5 alkene triols and 2-methyltetrols - showed the highest abundance at both sites when the city was under influence of inland air masses. The overall concentrations of SOA ISO were similar at both sites (0.4 and 0.3 μg m-3, or 16% and 7%, at UB and RS, respectively

  6. Chemical characterization of fine organic aerosol for source apportionment at Monterrey, Mexico

    NASA Astrophysics Data System (ADS)

    Mancilla, Y.; Mendoza, A.; Fraser, M. P.; Herckes, P.

    2015-07-01

    , source attribution results obtained using the CMB model indicate that emissions from motor vehicle exhausts are the most important, accounting for the 64 % of the PM2.5. The vegetative detritus and biomass burning had the smallest contribution (2.2 % of the PM2.5). To our knowledge, this is the second study to explore the broad chemical characterization of fine organic aerosol in Mexico and the first for the MMA.

  7. ACTRIS ACSM intercomparison - Part 2: Intercomparison of ME-2 organic source apportionment results from 15 individual, co-located aerosol mass spectrometers

    NASA Astrophysics Data System (ADS)

    Fröhlich, R.; Crenn, V.; Setyan, A.; Belis, C. A.; Canonaco, F.; Favez, O.; Riffault, V.; Slowik, J. G.; Aas, W.; Aijälä, M.; Alastuey, A.; Artiñano, B.; Bonnaire, N.; Bozzetti, C.; Bressi, M.; Carbone, C.; Coz, E.; Croteau, P. L.; Cubison, M. J.; Esser-Gietl, J. K.; Green, D. C.; Gros, V.; Heikkinen, L.; Herrmann, H.; Jayne, J. T.; Lunder, C. R.; Minguillón, M. C.; Močnik, G.; O'Dowd, C. D.; Ovadnevaite, J.; Petralia, E.; Poulain, L.; Priestman, M.; Ripoll, A.; Sarda-Estève, R.; Wiedensohler, A.; Baltensperger, U.; Sciare, J.; Prévôt, A. S. H.

    2015-06-01

    Chemically resolved atmospheric aerosol data sets from the largest intercomparison of the Aerodyne aerosol chemical speciation monitors (ACSMs) performed to date were collected at the French atmospheric supersite SIRTA. In total 13 quadrupole ACSMs (Q-ACSM) from the European ACTRIS ACSM network, one time-of-flight ACSM (ToF-ACSM), and one high-resolution ToF aerosol mass spectrometer (AMS) were operated in parallel for about 3 weeks in November and December~2013. Part 1 of this study reports on the accuracy and precision of the instruments for all the measured species. In this work we report on the intercomparison of organic components and the results from factor analysis source apportionment by positive matrix factorisation (PMF) utilising the multilinear engine 2 (ME-2). Except for the organic contribution of mass-to-charge ratio m/z 44 to the total organics (f44), which varied by factors between 0.6 and 1.3 compared to the mean, the peaks in the organic mass spectra were similar among instruments. The m/z 44 differences in the spectra resulted in a variable f44 in the source profiles extracted by ME-2, but had only a minor influence on the extracted mass contributions of the sources. The presented source apportionment yielded four factors for all 15 instruments: hydrocarbon-like organic aerosol (HOA), cooking-related organic aerosol (COA), biomass burning-related organic aerosol (BBOA) and secondary oxygenated organic aerosol (OOA). ME-2 boundary conditions (profile constraints) were optimised individually by means of correlation to external data in order to achieve equivalent / comparable solutions for all ACSM instruments and the results are discussed together with the investigation of the influence of alternative anchors (reference profiles). A comparison of the ME-2 source apportionment output of all 15 instruments resulted in relative standard deviations (SD) from the mean between 13.7 and 22.7 % of the source's average mass contribution depending on the

  8. Inter-comparison of source apportionment models for the estimation of wood burning aerosols during wintertime in an Alpine city (Grenoble, France)

    NASA Astrophysics Data System (ADS)

    Favez, O.; El Haddad, I.; Piot, C.; Boréave, A.; Abidi, E.; Marchand, N.; Jaffrezo, J.-L.; Besombes, J.-L.; Personnaz, M.-B.; Sciare, J.; Wortham, H.; George, C.; D'Anna, B.

    2010-01-01

    The emission of organic aerosols (OA) in the ambient air by residential wood burning is nowadays a subject of great scientific concern and a growing number of studies aim at apportioning the influence of such emissions on urban air quality. In the present study, results obtained using two commonly-used source apportionment models, i.e., Chemical Mass Balance (CMB, performed with off-line filter measurements) and Positive Matrix Factorization (PMF, applied to aerosol mass spectrometer measurements), as well as using the recently-proposed aethalometer model (based on the measurement of the aerosol light absorption at different wavelengths) are inter-compared. This work is performed using field data obtained during the winter season (14 to 30 January 2009) at an urban background site of a French Alpine city (Grenoble). Converging results from the different models indicate a major contribution of wood burning organic aerosols (OMwb) to the organic fraction, with mean OMwb contributions to total OA of about 67%, 60% and 38% for the CMB, the aethalometer and the AMS-PMF models, respectively. Quantitative discrepancies might notably be due to the overestimation of OMwb calculated by the CMB due to the loss of semi-volatile compounds from sources to receptor site, as well as to the accounting of oxidized primary wood burning organic (OPOAwb) aerosols within the Oxygenated Organic Aerosol (OOA) PMF-factor. This OOA factor accounts on average for about 50% of total OM, while non-combustion sources contribute to about 25% and 28% of total OM according to the CMB and aethalometer models, respectively. Each model suggests a mean contribution of fossil fuel emissions to total OM of about 10%. A good agreement is also obtained for the source apportionment of elemental carbon (EC) by both the CMB and aethalometer models, with fossil fuel emissions representing on average more than 80% of total EC.

  9. SOURCE APPORTIONMENT OF PRIMARY AND SECONDARY CARBONACEOUS AEROSOL IN THE UNITED STATES USING MODELS AND MEASUREMENTS

    EPA Science Inventory

    In this presentation, three diagnostic evaluation methods of model performance for carbonaceous aerosol are reviewed. The EC-tracer method is used to distinguish primary and secondary carbon, radiocarbon data are used to distinguish fossil-fuel and contemporary carbon, and organ...

  10. Aerosol species concentrations and source apportionment of ammonia at Rocky Mountain National Park.

    PubMed

    Malm, William C; Schichtel, Bret A; Barna, Michael G; Gebhart, Kristi A; Rodriguez, Marco A; Collett, Jeffrey L; Carrico, Christian M; Benedict, Katherine B; Prenni, Anthony J; Kreidenweis, Sonia M

    2013-11-01

    Changes in ecosystem function at Rocky Mountain National Park (RMNP) are occurring because of emissions of nitrogen and sulfate species along the Front Range of the Colorado Rocky Mountains, as well as sources farther east and west. The nitrogen compounds include both oxidized and reduced nitrogen. A year-long monitoring program of various oxidized and reduced nitrogen species was initiated to better understand their origins as well as the complex chemistry occurring during transport from source to receptor. Specifically the goals of the study were to characterize the atmospheric concentrations of nitrogen species in gaseous, particulate, and aqueous phases (precipitation and clouds) along the east and west sides of the Continental Divide; identify the relative contributions to atmospheric nitrogen species in RMNP from within and outside of the state of Colorado; identify the relative contributions to atmospheric nitrogen species in RMNP from emission sources along the Colorado Front Range versus other areas within Colorado; and identify the relative contributions to atmospheric nitrogen species from mobile sources, agricultural activities, and large and small point sources within the state of Colorado. Measured ammonia concentrations are combined with modeled releases of conservative tracers from ammonia source regions around the United States to apportion ammonia to its respective sources, using receptor modeling tools. PMID:24344569

  11. Source Apportionment of the Summer Time Carbonaceous Aerosol at Nordic Rural Background Sites

    EPA Science Inventory

    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 <10µ collected at four Nordic rural backgro...

  12. Source apportionment of size and time resolved trace elements and organic aerosols from an urban courtyard site in Switzerland

    NASA Astrophysics Data System (ADS)

    Richard, A.; Gianini, M. F. D.; Mohr, C.; Furger, M.; Bukowiecki, N.; Minguillón, M. C.; Lienemann, P.; Flechsig, U.; Appel, K.; Decarlo, P. F.; Heringa, M. F.; Chirico, R.; Baltensperger, U.; Prévôt, A. S. H.

    2011-02-01

    Time and size resolved data of trace elements were obtained from measurements with a rotating drum impactor (RDI) and subsequent X-ray fluorescence spectrometry. Trace elements can act as indicators for the identification of sources of particulate matter <10 μm (PM10) in ambient air. Receptor modeling was performed with positive matrix factorization (PMF) for trace element data from an urban background site in Zürich, Switzerland. Eight different sources were identified for the three examined size ranges (PM1-0.1, PM2.5-1 and PM10-2.5): secondary sulfate, wood combustion, fire works, road traffic, mineral dust, de-icing salt, industrial and local anthropogenic activities. The major component was secondary sulfate for the smallest size range; the road traffic factor was found in all three size ranges. This trace element analysis is complemented with data from an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (AMS), assessing the PM1 fraction of organic aerosols. A separate PMF analysis revealed three factors related to three of the sources found with the RDI: oxygenated organic aerosol (OOA, related to inorganic secondary sulfate), hydrocarbon like organic aerosol (HOA, related to road traffic) and biomass burning organic aerosol (BBOA), explaining 60%, 22% and 17% of total measured organics, respectively. Since different compounds are used for the source classification, a higher percentage of the ambient PM10 mass concentration can be apportioned to sources by the combination of both methods.

  13. Source apportionment of size and time resolved trace elements and organic aerosols from an urban courtyard site in Switzerland

    NASA Astrophysics Data System (ADS)

    Richard, A.; Gianini, M. F. D.; Mohr, C.; Furger, M.; Bukowiecki, N.; Minguillón, M. C.; Lienemann, P.; Flechsig, U.; Appel, K.; Decarlo, P. F.; Heringa, M. F.; Chirico, R.; Baltensperger, U.; Prévôt, A. S. H.

    2011-09-01

    Time and size resolved data of trace elements were obtained from measurements with a rotating drum impactor (RDI) and subsequent X-ray fluorescence spectrometry. Trace elements can act as indicators for the identification of sources of particulate matter <10 μm (PM10) in ambient air. Receptor modeling was performed with positive matrix factorization (PMF) for trace element data from an urban background site in Zürich, Switzerland. Eight different sources were identified for the three examined size ranges (PM1-0.1, PM2.5-1 and PM10-2.5): secondary sulfate, wood combustion, fire works, road traffic, mineral dust, de-icing salt, industrial and local anthropogenic activities. The major component was secondary sulfate for the smallest size range; the road traffic factor was found in all three size ranges. This trace element analysis is complemented with data from an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (AMS), assessing the PM1 fraction of organic aerosols. A separate PMF analysis revealed three factors related to three of the sources found with the RDI: oxygenated organic aerosol (OOA, related to inorganic secondary sulfate), hydrocarbon-like organic aerosol (HOA, related to road traffic) and biomass burning organic aerosol (BBOA), explaining 60 %, 22 % and 17 % of total measured organics, respectively. Since different compounds are used for the source classification, a higher percentage of the ambient PM10 mass concentration can be apportioned to sources by the combination of both methods.

  14. CHARACTERIZATION AND SOURCE APPORTIONMENT

    EPA Science Inventory

    The results from this core's studies will be essential to interpret the results of the other cores. These measurements will permit development of a delivery system to provide exposures of specific radical species on model particles for toxicological studies. Source apportion...

  15. Source apportionment and dynamic changes of carbonaceous aerosols during the haze bloom-decay process in China based on radiocarbon and organic molecular tracers

    NASA Astrophysics Data System (ADS)

    Liu, Junwen; Li, Jun; Liu, Di; Ding, Ping; Shen, Chengde; Mo, Yangzhi; Wang, Xinming; Luo, Chunling; Cheng, Zhineng; Szidat, Sönke; Zhang, Yanlin; Chen, Yingjun; Zhang, Gan

    2016-03-01

    Fine carbonaceous aerosols (CAs) is the key factor influencing the currently filthy air in megacities in China, yet few studies simultaneously focus on the origins of different CAs species using specific and powerful source tracers. Here, we present a detailed source apportionment for various CAs fractions, including organic carbon (OC), water-soluble OC (WSOC), water-insoluble OC (WIOC), elemental carbon (EC) and secondary OC (SOC) in the largest cities of North (Beijing, BJ) and South China (Guangzhou, GZ), using the measurements of radiocarbon and anhydrosugars. Results show that non-fossil fuel sources such as biomass burning and biogenic emission make a significant contribution to the total CAs in Chinese megacities: 56 ± 4 in BJ and 46 ± 5 % in GZ, respectively. The relative contributions of primary fossil carbon from coal and liquid petroleum combustions, primary non-fossil carbon and secondary organic carbon (SOC) to total carbon are 19, 28 and 54 % in BJ, and 40, 15 and 46 % in GZ, respectively. Non-fossil fuel sources account for 52 in BJ and 71 % in GZ of SOC, respectively. These results suggest that biomass burning has a greater influence on regional particulate air pollution in North China than in South China. We observed an unabridged haze bloom-decay process in South China, which illustrates that both primary and secondary matter from fossil sources played a key role in the blooming phase of the pollution episode, while haze phase is predominantly driven by fossil-derived secondary organic matter and nitrate.

  16. Source apportionment and dynamic changes of carbonaceous aerosols during the haze bloom-decay process in China based on radiocarbon and organic molecular tracers

    NASA Astrophysics Data System (ADS)

    Liu, J.; Li, J.; Liu, D.; Ding, P.; Shen, C.; Mo, Y.; Wang, X.; Luo, C.; Cheng, Z.; Szidat, S.; Zhang, Y.; Chen, Y.; Zhang, G.

    2015-12-01

    Fine carbonaceous aerosols (CAs) is the key factor influencing the currently filthy air in megacities of China, yet seldom study simultaneously focuses on the origins of different CAs species using specific and powerful source tracers. Here, we present a detailed source apportionment for various CAs fractions, including organic carbon (OC), water-soluble OC (WSOC), water-insoluble OC (WIOC), elemental carbon (EC) and secondary OC (SOC) in the largest cities of North (Beijing, BJ) and South China (Guangzhou, GZ), respectively, using the measurements of radiocarbon and anhydrosugars. Results show that non-fossil fuel sources such as biomass burning and biogenic emission make a significant contribution to the total CAs in Chinese megacities: 56 ± 4 % in BJ and 46 ± 5 % in GZ, respectively. The relative contributions of primary fossil carbon from coal and liquid petroleum combustions, primary non-fossil carbon and secondary organic carbon (SOC) to total carbon are 19, 28 and 54 % in BJ, and 40, 15 and 46 % in GZ, respectively. Non-fossil fuel sources account for 52 % in BJ and 71 % in GZ of SOC, respectively. These results suggest that biomass burning has a greater influence on regional particulate air pollution in North China than in South China. We observed an unabridged haze bloom-decay process in South China, which illustrates that both primary and secondary matter from fossil sources played a key role in the blooming phase of the pollution episode, while haze phase is predominantly driven by fossil-derived secondary organic matter and nitrate.

  17. PM SOURCE APPORTIONMENT/RECEPTOR MODELING

    EPA Science Inventory

    Source apportionment (receptor) models are mathematical procedures for identifying and quantifying the sources of ambient air pollutants and their effects at a site (the receptor), primarily on the basis of species concentration measurements at the receptor, and generally without...

  18. Source apportionment methods applied to the determination of the origin of ambient aerosols that affect visibility in forested areas

    NASA Astrophysics Data System (ADS)

    Stevens, Robert K.; Dzubay, Thomas G.; Lewis, Charles W.; Shaw, Robert W.

    An aerosol characterization, visibility, and receptor modeling study was conducted in the Shenandoah Valley, VA between 14 July and 15 August 1980. The objectives of this study were to: (1) determine the origin of the ambient particles, (2) determine the major chemical species contributing to the light extinction coefficient, (3) evaluate analytical methods to characterize aerosols and (4) provide data for comparison with chemical composition of aerosols collected in the Great Smoky Mountains and in the Abastumani Mountains of Georgian Soviet Socialist Republic. The average sulfate concentrations measured in fine particles (<2.5μm) at these three locations were: 12.0μgm -3 at Great Smoky Mountains; 13.6 μg m -3 at Shenandoah Valley, and 4.6 μg m -3 at Abastumani Mountains; the fractions of sulfate in the fine particle mass concentrations at each site were 0.50,0.50 and 0.38, respectively. For the two studies in the United States, the fine particle sulfate during sulfate maxima was mostly in the form of ammonium acid sulfate. Factor analysis of the fine aerosol composition measured in the Shenandoah Valley yielded a persistent factor containing large loadings on mass, SO 2-4, S, NH +4, H +, Se and total nitrate (sum of particulate nitrate and nitric acid), which is characteristic of coal-fired sources. This factor analysis grouping along with additional emissions information suggests that coal-fired power plants are the principal source of sulfate and nitrate.

  19. Source apportionment using radiocarbon and organic tracers for PM2.5 carbonaceous aerosols in Guangzhou, South China: contrasting local- and regional-scale haze events.

    PubMed

    Liu, Junwen; Li, Jun; Zhang, Yanlin; Liu, Di; Ding, Ping; Shen, Chengde; Shen, Kaijun; He, Quanfu; Ding, Xiang; Wang, Xinming; Chen, Duohong; Szidat, Sönke; Zhang, Gan

    2014-10-21

    We conducted a source apportionment and investigated the atmospheric behavior of carbonaceous aerosols during hazy and normal days using radiocarbon ((14)C) and biomass burning/secondary organic aerosol (SOA) tracers during winter in Guangzhou, China. Haze episodes were formed either abruptly by local emissions or through the accumulation of particles transported from other areas. The average contributions of fossil carbon to elemental carbon (EC), water-insoluble organic carbon, and water-soluble organic carbon were 71 ± 10%, 40 ± 6% and 33 ± 3%, respectively. High contributions of fossil carbon to EC (80-90%) were observed for haze samples that were substantially impacted by local emissions, as were the highest (lowest) ratios for NO3(-)/SO4(2-) (OC/EC), which indicates that these particles mainly came from local vehicle exhaust. Low contributions of fossil carbon to EC (60-70%) were found for haze particles impacted by regional transport. Secondary organic carbon (SOC) calculated using SOA tracers accounts for only ∼ 20% of the SOC estimated by (14)C, which is probably because some important volatile organic carbons are not taken into account in the SOA tracer calculation method and because of the large discrepancy in ambient conditions between the atmosphere and smog chambers. A total of 33 ± 11% of the SOC was of fossil origin, a portion of which could be influenced by humidity. PMID:25264588

  20. Radiocarbon-Based Source Apportionment of the Water-Soluble Organic Carbon (wsoc) of Atmospheric Aerosols in South and East Asia

    NASA Astrophysics Data System (ADS)

    Kirillova, E. N.; Sheesley, R. J.; Andersson, A.; Gustafsson, O.; Safai, P. D.; Budhavant, K.; Rao, P. S.; Kang, E.; Han, J.; Lee, M.

    2011-12-01

    The air quality and regional climate in South and East Asia are considerably affected by atmospheric aerosols produced by anthropogenic activities. Recent studies have investigated the sources of the black carbon aerosol component in these regions. This study seeks to make progress in apportioning the sources of the water soluble organic carbon (WSOC) component, which makes up 20-65% of the carbonaceous aerosol mass in these areas. WSOC is important as it enhances the ability of particles to serve as cloud condensation nuclei (CCN) and, therefore, has an impact on regional climate and radiative forcing. Atmospheric particulate matter was collected during fifteen-month continuous sampling campaigns Jan 2008 - March 2009 at both the Maldives Climate Observatory at Hannimaadho (MCOH) and at the Sinhagad hilltop sampling site of the Indian Institute of Tropical Meteorology (SIN) in central-western India. The radiocarbon method is an ideal approach to identify fossil sources (14C "dead") compared to biogenic and biomass combustion products (with a contemporary 14C signal). WSOC is a large fraction of organic aerosols and its annual average contribution to TOC during 2008 is 26% at MCOH and 40% at SIN. There is a distinct seasonal variability in WSOC concentrations at both sites with high concentrations during the winter season (0.92±0.49μg m-3 at MCOH and 3.5±2.0μg m-3 at SIN) and very low concentrations during the summer monsoon season (0.08±0.04μg m-3 at MCOH and 0.27±0.20μg m-3 at SIN). The radiocarbon source apportionment of WSOC in winter dry season was similar at MCOH and SIN with 80-85% from biogenic/biomass combustion and the rest from fossil fuel precursors. For the rest of the year, the biogenic/biomass contribution to WSOC is higher at the Indian Ocean site (86-93%) compared to the Indian site (74-83%). In March 2011 the GoPoEx2011 intensive sampling campaign at the Gosan ABC Superstation, Jeju Island, South Korea was dedicated to study atmospheric

  1. Reconciliation and interpretation of Big Bend National Park particulate sulfur source apportionment: results from the Big Bend Regional Aerosol and Visibility Observational Study--part I.

    PubMed

    Schichtel, Bret A; Gebhart, Kristi A; Malm, William C; Barna, Michael G; Pitchford, Marc L; Knipping, Eladio M; Tombach, Ivar H

    2005-11-01

    The Big Bend Regional Aerosol and Visibility Observational (BRAVO) study was an intensive monitoring study from July through October 1999 followed by extensive assessments to determine the causes and sources of haze in Big Bend National Park, located in Southwestern Texas. Particulate sulfate compounds are the largest contributor of haze at Big Bend, and chemical transport models (CTMs) and receptor models were used to apportion the sulfate concentrations at Big Bend to North American source regions and the Carbón power plants, located 225 km southeast of Big Bend in Mexico. Initial source attribution methods had contributions that varied by a factor of > or =2. The evaluation and comparison of methods identified opposing biases between the CTMs and receptor models, indicating that the ensemble of results bounds the true source attribution results. The reconciliation of these differences led to the development of a hybrid receptor model merging the CTM results and air quality data, which allowed a nearly daily source apportionment of the sulfate at Big Bend during the BRAVO study. The best estimates from the reconciliation process resulted in sulfur dioxide (SO2) emissions from U.S. and Mexican sources contributing approximately 55% and 38%, respectively, of sulfate at Big Bend. The distribution among U.S. source regions was Texas, 16%; the Eastern United States, 30%; and the Western United States, 9%. The Carbón facilities contributed 19%, making them the largest single contributing facility. Sources in Mexico contributed to the sulfate at Big Bend on most days, whereas contributions from Texas and Eastern U.S. sources were episodic, with their largest contributions during Big Bend sulfate episodes. On the 20% of the days with the highest sulfate concentrations, U.S. and Mexican sources contributed approximately 71% and 26% of the sulfate, respectively. However, on the 20% of days with the lowest sulfate concentrations, Mexico contributed 48% compared with 40

  2. Aerosol Composition and Source Apportionment in the Mexico City Metropolitan Area with PIXE/PESA/STIM and Multivariate Analysis

    SciTech Connect

    Johnson, Kirsten S.; de Foy, B.; Zuberi, Bilal M.; Molina, Luisa; Molina, Mario J.; Xie, YuLong; Laskin, Alexander; Shutthanandan, V.

    2006-10-12

    Aerosols play an important role in the atmosphere but are poorly characterized, particularly in urban areas like the Mexico City Metropolitan Area (MCMA). The chemical composition of urban particles must be known to assess their effects on the environment, and specific particulate emissions sources should be identified to establish ef- 5 fective pollution control standards. For these reasons, samples of particulate matter _2.5 µm (PM2.5) were collected during the MCMA-2003 Field Campaign for elemental and multivariate analyses. Proton-Induced X-ray Emission (PIXE), Proton-Elastic Scattering Analysis (PESA) and Scanning Transmission Ion Microscopy (STIM) techniques were done to determine concentrations of 19 elements from Na to Pb, hydrogen, and 10 total mass, respectively. The most abundant elements from PIXE analysis were S, Si, K, Fe, Ca, and Al, while the major emissions sources associated with these elements were industry, wind-blown soil, and biomass burning. Wind trajectories suggest that metals associated with industrial emissions came from northern areas of the city whereas soil aerosols came from the southwest and increased in concentration during 15 dry conditions. Elemental markers for fuel oil combustion V and Ni correlated with a large SO2 plume to suggest an anthropogenic, rather than volcanic, emissions source. By subtracting major components of soil and sulfates determined by PIXE analysis from STIM total mass measurements, we estimate that approximately 50% of PM2.5 consisted of carbonaceous material.

  3. ORGANIC MOLECULAR MARKER ANALYSIS OF LOW VOLUME RESIDENTIAL SAMPLES FOR SOURCE APPORTIONMENT IN THE DETROIT EXPOSURE AND AEROSOL RESEARCH STUDY

    EPA Science Inventory

    This abstract describes a poster on results for organic speciation analysis for Detroit Exposure and Aerosol Research Study (DEARS) to be presented at the 2006 International Aerosol Conference sponsored by the American Association for Aerosol Research in St. Paul, Minnesota on Se...

  4. Regional air quality in Leipzig, Germany: detailed source apportionment of size-resolved aerosol particles and comparison with the year 2000.

    PubMed

    van Pinxteren, D; Fomba, K W; Spindler, G; Müller, K; Poulain, L; Iinuma, Y; Löschau, G; Hausmann, A; Herrmann, H

    2016-07-18

    A detailed source apportionment of size-resolved aerosol particles in the area of Leipzig, Germany, was performed. Sampling took place at four sites (traffic, traffic/residential, urban background, regional background) in parallel during summer 2013 and the winters 2013/14/15. Twenty-one samples were taken per season with a 5-stage Berner impactor and analysed for particulate mass, inorganic ions, organic and elemental carbon, water-soluble organic carbon, trace metals, and a wide range of organic species. The compositional data were used to estimate source contributions to particulate matter (PM) in quasi-ultrafine (up to 140 nm), accumulation mode, and coarse size ranges using Positive Matrix Factorisation (PMF) receptor modelling. Traffic (exhaust and general traffic emissions), coal combustion, biomass combustion, photochemistry, general secondary formation, cooking, fungal spores, urban dust, fresh sea/road salt, and aged sea salt were all found to contribute to different extents to observed PM concentrations. PMF derived estimates agreed reasonably with estimates from established macrotracer approaches. Quasi-ultrafine PM originated mainly from traffic (20-50%) and photochemistry (30-50%) in summer, while it was dominated by solid fuel (mainly biomass) combustion in winter (50-70%). Tentatively identified cooking aerosol contributed up to 36% on average at the residential site. For accumulation mode particles, two secondary sources typically contributed 40-90% to particle mass. In winter, biomass and coal combustion contributions were up to ca. 25% and 45%, respectively. Main sources of coarse particles were diverse and included nearly all PMF-resolved ones depending on season and air mass origin. For PM10, traffic (typically 20-40% at kerbside sites), secondary formation (30-60%), biomass combustion (10-15% in winter), and coal combustion (30-40% in winter with eastern air mass inflow) were the main quantified sources. At the residential site, contributions

  5. Source apportionment of organic compounds in Berlin using positive matrix factorization - assessing the impact of biogenic aerosol and biomass burning on urban particulate matter.

    PubMed

    Wagener, Sandra; Langner, Marcel; Hansen, Ute; Moriske, Heinz-Jörn; Endlicher, Wilfried R

    2012-10-01

    Source apportionment of 13 organic compounds, elemental carbon and organic carbon of ambient PM(10) and PM(1) was performed with positive matrix factorization (PMF). Samples were collected at three sites characterized by different vegetation influences in Berlin, Germany in 2010. The aim was to determine organic, mainly biogenic sources and their impact on urban aerosol collected in a densely populated region. A 6-factor solution provided the best data fit for both PM-fractions, allowing the sources isoprene- and α-pinene-derived secondary organic aerosol (SOA), bio primary, primarily attributable to fungal spores, bio/urban primary including plant fragments in PM(10) and cooking and traffic emissions in PM(1), biomass burning and combustion fossil to be identified. With mean concentrations up to 2.6 μg Cm(-3), biomass burning dominated the organic fraction in cooler months. Concentrations for α-pinene-derived SOA exceeded isoprene-derived concentrations. Estimated secondary organic carbon contributions to total organic carbon (OC) were between 7% and 42% in PM(10) and between 11% and 60% in PM(1), which is slightly lower than observed for US- or Asian cities. Primary biogenic emissions reached up to 33% of OC in the PM(10)-fraction in the late summer and autumn months. Temperature-dependence was found for both SOA-factors, correlations with ozone and mix depth only for the α-pinene-derived SOA-factor. Latter indicated input of α-pinene from the borders, highlighting differences in the origin of the precursors of both factors. Most factors were regionally distributed. High regional distribution was found to be associated with stronger influence of ambient parameters and higher concentrations at the background station. A significant contribution of biogenic emissions and biomass burning to urban organic aerosol could be stated. This indicates a considerable impact on PM concentrations also in cities in a densely populated area, and should draw the attention

  6. Radiocarbon-based source apportionment of black carbon (BC) in PM 10 aerosols from residential area of suburban Tokyo

    NASA Astrophysics Data System (ADS)

    Uchida, Masao; Kumata, Hidetoshi; Koike, Yasuyo; Tsuzuki, Mikio; Uchida, Tatsuya; Fujiwara, Kitao; Shibata, Yasuyuki

    2010-04-01

    The AMS technique was applied to analyse black carbon (BC), total organic carbon (TOC), and previously reported polycyclic aromatic hydrocarbons (PAHs) in PM 10 aerosols from a residential area, suburban Tokyo, to determine natural abundance of radiocarbon ( 14C), an ideal tracer to distinguish fossil fuel ( 14C-free) from modern biomass combustion sources of pyrolytic products. The 14C concentrations in BC, isolated using the CTO-375 method, were 42% and 30% pMC (in terms of percent Modern Carbon: pMC) in summer and winter, respectively. The 14C concentrations in BC were also compared with those of compound-class specific 14C content of PAHs previously reported for the same samples: they were 45% and 33% pMC in summer and winter, respectively. The 14C signals of BC were identical to those of high molecular weight (MW ⩾ 226, 5-6 rings) PAHs. The resemblance between 14C signals of BC and PAHs can be referred as a 'certificate' for the validity of the BC isolation method employed in this study. Also, it suggests that 14C-BC approach can be a surrogate for PAHs specific 14C analyses to monitor seasonal source variation of combustion-derived pyrolytic products. On the other hand, 14C contents of total organic carbon in 2004 were 61% and 42% pMC in summer and winter, respectively. This is likely attributed to higher contribution of plant activity in summer.

  7. Spatial and Temporal Variations of Aerosols Around Beijing in the Summer 2006: Model Evaluation and Source Apportionment

    SciTech Connect

    Matsui, Hitoshi; Koike, Makoto; Kondo, Yutaka; Takegawa, Nobuyuki; Kita, K.; Miyazaki, Y.; Hu, M.; Chang, S-Y; Blake, D. R.; Fast, Jerome D.; Zaveri, Rahul A.; Streets, D. G.; Zhang, Q.; Zhou, T.

    2009-08-15

    Regional aerosol model calculations were made using the WRF-CMAQ and WRF-chem models to study spatial and temporal variations of aerosols around Beijing, China, in August and September 2006 when the CAREBEIJING-2006 campaign was conducted. Model calculations were compared with in-situ observations made at the urban site in Beijing and suburb site in Yufa, which is 50 km to the south of Beijing. In general, the two model calculations reproduced features of temporal variations of meteorological parameters and concentrations of elemental carbon (EC) and inorganic aerosols (sulfate, ammonium, and nitrate). Spatial distributions of aerosol optical depth (AOD) obtained by the MODIS satellite sensor are also generally well reproduced. Model calculations show that enhancements in inorganic aerosol concentrations simultaneously observed at the two sites 4 to 5 times during the one-month observation period were resulted by accumulation of pollutants under stagnated air condition. Because Beijing is located at the north border the high anthropogenic emission area (the Great North China Plain), northward motion of air under the influence of anti-cyclone system caused enhancements in fine aerosol concentrations at Beijing. Concentrations of primary aerosols, such as EC, are found to be generally controlled by emissions within 100 km around Beijing within previous 24 hours. On the other hand, emissions as far as 500 km within previous 3 days were found to affect concentrations of secondary aerosols, such as sulfate. Because of significant contributions of secondary aerosols in Beijing, regional emission controls are found to be necessary for improvement of air quality in Beijing.

  8. IMPROVING SOURCE PROFILES AND APPORTIONMENT OF COMBUSTION SOURCES USING THERMAL CARBON FRACTIONS IN MULTIVARIATE RECEPTOR MODELS

    EPA Science Inventory

    The purpose of this study was to improve combustion source profiles and apportionment of a PM2.5 urban aerosol by using 7 individual organic and elemental carbon thermal fractions in place of total organic and elemental carbon. This study used 3 years (96-99) of speciated data...

  9. Source apportionment of airborne particulates through receptor modeling: Indian scenario

    NASA Astrophysics Data System (ADS)

    Banerjee, Tirthankar; Murari, Vishnu; Kumar, Manish; Raju, M. P.

    2015-10-01

    Airborne particulate chemistry mostly governed by associated sources and apportionment of specific sources is extremely essential to delineate explicit control strategies. The present submission initially deals with the publications (1980s-2010s) of Indian origin which report regional heterogeneities of particulate concentrations with reference to associated species. Such meta-analyses clearly indicate the presence of reservoir of both primary and secondary aerosols in different geographical regions. Further, identification of specific signatory molecules for individual source category was also evaluated in terms of their scientific merit and repeatability. Source signatures mostly resemble international profile while, in selected cases lack appropriateness. In India, source apportionment (SA) of airborne particulates was initiated way back in 1985 through factor analysis, however, principal component analysis (PCA) shares a major proportion of applications (34%) followed by enrichment factor (EF, 27%), chemical mass balance (CMB, 15%) and positive matrix factorization (PMF, 9%). Mainstream SA analyses identify earth crust and road dust resuspensions (traced by Al, Ca, Fe, Na and Mg) as a principal source (6-73%) followed by vehicular emissions (traced by Fe, Cu, Pb, Cr, Ni, Mn, Ba and Zn; 5-65%), industrial emissions (traced by Co, Cr, Zn, V, Ni, Mn, Cd; 0-60%), fuel combustion (traced by K, NH4+, SO4-, As, Te, S, Mn; 4-42%), marine aerosols (traced by Na, Mg, K; 0-15%) and biomass/refuse burning (traced by Cd, V, K, Cr, As, TC, Na, K, NH4+, NO3-, OC; 1-42%). In most of the cases, temporal variations of individual source contribution for a specific geographic region exhibit radical heterogeneity possibly due to unscientific orientation of individual tracers for specific source and well exaggerated by methodological weakness, inappropriate sample size, implications of secondary aerosols and inadequate emission inventories. Conclusively, a number of challenging

  10. Accuracy and precision of 14C-based source apportionment of organic and elemental carbon in aerosols using the Swiss_4S protocol

    NASA Astrophysics Data System (ADS)

    Mouteva, G. O.; Fahrni, S. M.; Santos, G. M.; Randerson, J. T.; Zhang, Y.-L.; Szidat, S.; Czimczik, C. I.

    2015-09-01

    Aerosol source apportionment remains a critical challenge for understanding the transport and aging of aerosols, as well as for developing successful air pollution mitigation strategies. The contributions of fossil and non-fossil sources to organic carbon (OC) and elemental carbon (EC) in carbonaceous aerosols can be quantified by measuring the radiocarbon (14C) content of each carbon fraction. However, the use of 14C in studying OC and EC has been limited by technical challenges related to the physical separation of the two fractions and small sample sizes. There is no common procedure for OC/EC 14C analysis, and uncertainty studies have largely focused on the precision of yields. Here, we quantified the uncertainty in 14C measurement of aerosols associated with the isolation and analysis of each carbon fraction with the Swiss_4S thermal-optical analysis (TOA) protocol. We used an OC/EC analyzer (Sunset Laboratory Inc., OR, USA) coupled to a vacuum line to separate the two components. Each fraction was thermally desorbed and converted to carbon dioxide (CO2) in pure oxygen (O2). On average, 91 % of the evolving CO2 was then cryogenically trapped on the vacuum line, reduced to filamentous graphite, and measured for its 14C content via accelerator mass spectrometry (AMS). To test the accuracy of our setup, we quantified the total amount of extraneous carbon introduced during the TOA sample processing and graphitization as the sum of modern and fossil (14C-depleted) carbon introduced during the analysis of fossil reference materials (adipic acid for OC and coal for EC) and contemporary standards (oxalic acid for OC and rice char for EC) as a function of sample size. We further tested our methodology by analyzing five ambient airborne particulate matter (PM2.5) samples with a range of OC and EC concentrations and 14C contents in an interlaboratory comparison. The total modern and fossil carbon blanks of our setup were 0.8 ± 0.4 and 0.67 ± 0.34 μg C, respectively

  11. Accuracy and precision of 14C-based source apportionment of organic and elemental carbon in aerosols using the Swiss_4S protocol

    NASA Astrophysics Data System (ADS)

    Mouteva, G. O.; Fahrni, S. M.; Santos, G. M.; Randerson, J. T.; Zhang, Y. L.; Szidat, S.; Czimczik, C. I.

    2015-04-01

    Aerosol source apportionment remains a critical challenge for understanding the transport and aging of aerosols, as well as for developing successful air pollution mitigation strategies. The contributions of fossil and non-fossil sources to organic carbon (OC) and elemental carbon (EC) in carbonaceous aerosols can be quantified by measuring the radiocarbon (14C) content of each carbon fraction. However, the use of 14C in studying OC and EC has been limited by technical challenges related to the physical separation of the two fractions and small sample sizes. There is no common procedure for OC/EC 14C analysis, and uncertainty studies have largely focused on the precision of yields. Here, we quantified the uncertainty in 14C measurement of aerosols associated with the isolation and analysis of each carbon fraction with the Swiss_4S thermal-optical analysis (TOA) protocol. We used an OC/EC analyzer (Sunset Laboratory Inc., OR, USA) coupled to vacuum line to separate the two components. Each fraction was thermally desorbed and converted to carbon dioxide (CO2) in pure oxygen (O2). On average 91% of the evolving CO2 was then cryogenically trapped on the vacuum line, reduced to filamentous graphite, and measured for its 14C content via accelerator mass spectrometry (AMS). To test the accuracy of our set-up, we quantified the total amount of extraneous carbon introduced during the TOA sample processing and graphitization as the sum of modern and fossil (14C-depleted) carbon introduced during the analysis of fossil reference materials (adipic acid for OC and coal for EC) and contemporary standards (oxalic acid for OC and rice char for EC) as a function of sample size. We further tested our methodology by analyzing five ambient airborne particulate matter (PM2.5) samples with a range of OC and EC concentrations and 14C contents in an interlaboratory comparison. The total modern and fossil carbon blanks of our set-up were 0.8 ± 0.4 and 0.67 ± 0.34 μg C, respectively

  12. SoFi, an IGOR-based interface for the efficient use of the generalized multilinear engine (ME-2) for the source apportionment: ME-2 application to aerosol mass spectrometer data

    NASA Astrophysics Data System (ADS)

    Canonaco, F.; Crippa, M.; Slowik, J. G.; Baltensperger, U.; Prévôt, A. S. H.

    2013-12-01

    Source apportionment using the bilinear model through a multilinear engine (ME-2) was successfully applied to non-refractory organic aerosol (OA) mass spectra collected during the winter of 2011 and 2012 in Zurich, Switzerland using the aerosol chemical speciation monitor (ACSM). Five factors were identified: low-volatility oxygenated OA (LV-OOA), semivolatile oxygenated OA (SV-OOA), hydrocarbon-like OA (HOA), cooking OA (COA) and biomass burning OA (BBOA). A graphical user interface SoFi (Source Finder) was developed at PSI in order to facilitate the testing of different rotational techniques available within the ME-2 engine by providing a priori factor profiles for some or all of the expected factors. ME-2 was used to test the positive matrix factorization (PMF) model, the fully constrained chemical mass balance (CMB) model, and partially constrained models utilizing a values and pulling equations. Within the set of model solutions determined to be environmentally reasonable, BBOA and SV-OOA factor mass spectra and time series showed the greatest variability. This variability represents the uncertainty in the model solution and indicates that analysis of model rotations provides a useful approach for assessing the uncertainty of bilinear source apportionment models.

  13. CMB source apportionment during REVEAL

    SciTech Connect

    Lowenthal, D.H.; Gertler, A.W.; Wittorff, D.; Sakiyama, S.

    1997-01-01

    Source contributions to PM{sub 2.5} aerosol measured at Chilliwack and Pitt Meadows in the Lower Fraser Valley, B.C., Canada, during the REVEAL study, were estimated using chemical mass balance (CMB) receptor modeling. ON average, motor vehicles accounted for 34 and 43% of PM{sub 2.5} at Chilliwack and Pitt Meadows, respectively. Secondary sulfate and secondary nitrate were the next most significant PM{sub 2.5} components, accounting for 25 and 27%, respectively, at Chilliwack, and 27 and 12%, respectively, at Pitt Meadows. Geological material accounted for 3 and 5% of PM{sub 2.5} at Chilliwack and Pitt Meadows, respectively. A significant contribution of wood smoke was estimated for both sites: 8% at Chilliwack and 9% at Pitt Meadows.

  14. Submicron aerosol analysis and organic source apportionment in an urban atmosphere in Pearl River Delta of China using high-resolution aerosol mass spectrometry

    NASA Astrophysics Data System (ADS)

    He, Ling-Yan; Huang, Xiao-Feng; Xue, Lian; Hu, Min; Lin, Yun; Zheng, Jun; Zhang, Renyi; Zhang, Yuan-Hang

    2011-06-01

    The Pearl River Delta (PRD) region in South China is one of the most economically developed regions in China while also noted for its severe air pollution, especially in the urban environments. In order to understand in depth the aerosol chemistry and the emission sources in PRD, an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) was deployed at an urban site in the Hong Kong-Shenzhen metropolitan area between 25 October and 2 December 2009. Ten minute-resolved measurement data were analyzed, and an average mass concentration of 44.5 ± 34.0 μg m-3 was calculated for the entire campaign. On average, organic matter was the most abundant PM1 component accounting for 39.7% of the total mass, followed by sulfate (24.5%), black carbon (measured by aethalometer, 14.0%), ammonium (10.2%), nitrate (10.0%), and chloride (1.6%). Moreover, organic matter comprised an increasing fraction of the PM1 loading as the PM1 loading increased, denoting its key role in particulate pollution in this region. Calculations of organic elemental composition based on the high-resolution organic mass spectra obtained indicated that C, H, O, and N on average contributed 33.8%, 55.1%, 10.2%, and 0.9%, respectively, to the total atomic numbers of organic aerosol (OA), which corresponded to an OM/OC ratio (the ratio of organic matter mass/organic carbon mass) of 1.57 ± 0.08. Positive matrix factorization analysis was then conducted on the high-resolution organic mass spectral data set. Four OA components were identified, including a hydrocarbon-like (HOA), a biomass burning (BBOA), and two oxygenated (LV-OOA and SV-OOA) components, which on average accounted for 29.5%, 24.1%, 18.8%, and 27.6%, respectively, of the total organic mass. The HOA was found to have contributions from both fossil fuel combustion and cooking emissions, while the BBOA was well correlated with acetonitrile, a known biomass burning marker. The LV-OOA and SV-OOA corresponded to more aged and

  15. Characterization and source apportionment of aerosol light extinction with a coupled model of CMB-IMPROVE in Hangzhou, Yangtze River Delta of China

    NASA Astrophysics Data System (ADS)

    Wang, Jiao; Zhang, Yu-fen; Feng, Yin-chang; Zheng, Xian-jue; Jiao, Li; Hong, Sheng-mao; Shen, Jian-dong; Zhu, Tan; Ding, Jing; Zhang, Qi

    2016-09-01

    To investigate the characteristics and sources of aerosol light extinction in the Yangtze River Delta of China, a campaign was carried out in Hangzhou from December 2013 to November 2014. Hourly data for air pollutants including PM2.5, SO2, NO2, O3 and CO, and aerosol optical properties including aerosol scattering coefficient and aerosol absorbing coefficient was obtained in the environmental air quality automatic monitoring station. Meteorological parameters were measured synchronously in the automated meteorology monitoring station. Additionally, around seven sets of ambient PM2.5 samples per month were collected and analyzed during the campaign. The annual mean aerosol scattering coefficient, aerosol absorbing coefficient and aerosol single scattering albedo measured in this study was 514 ± 284 Mm- 1, 35 ± 20 Mm- 1 and 94% respectively. The aerosol extinction coefficient reconstructed using the modified IMPROVE (Interagency Monitoring of Protected Visual Environment) formula was compared to the measured extinction coefficient. Better correlations could be found between the measured and reconstructed extinction coefficient when RH was under 90%. A coupled model of CMB (chemical mass balance) and modified IMPROVE was used to apportion the sources of aerosol light extinction in Hangzhou. Vehicle exhaust, secondary nitrate and secondary sulfate were identified as the most significant sources for aerosol light extinction, accounted for 30.2%, 24.1% and 15.8% respectively.

  16. Mexico City Aerosol Analysis during MILAGRO using High Resolution Aerosol Mass Spectrometry at the Urban Supersite (T0). Part 1: Fine Particle Composition and Organic Source Apportionment

    SciTech Connect

    Aiken, Allison; Salcedo, D.; Cubison, Michael J.; Huffman, J.; DeCarlo, Peter; Ulbrich, Ingrid M.; Docherty, Kenneth S.; Sueper, D. T.; Kimmel, Joel; Worsnop, Douglas R.; Trimborn, Achim; Northway, Megan; Stone, Elizabeth A.; Schauer, James J.; Volkamer, Rainer M.; Fortner, Edward; de Foy, B.; Wang, Jian; Laskin, Alexander; Shutthanandan, V.; Zheng, Junsheng; Zhang, Renyi; Gaffney, Jeffrey S.; Marley, Nancy A.; Paredes-Miranda, Guadalupe L.; Arnott, W. P.; Molina, Luisa T.; Sosa, G.; Jimenez, Jose L.

    2009-09-11

    Submicron aerosol was analyzed during the MILAGRO field campaign in March 2006 at the T0 urban supersite in Mexico City with a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) and complementary instrumentation. Mass concentrations, diurnal cycles, and size distributions of inorganic and organic species are similar to results from the CENICA supersite in April 2003 with organic aerosol (OA) comprising about half of the fine PM mass. Positive Matrix Factorization (PMF) analysis of the high resolution OA spectra identifies three major components: chemically-reduced urban primary emissions (hydrocarbon-like OA, HOA), oxygenated OA (OOA, mostly secondary OA or SOA), and biomass burning OA (BBOA) that correlates with levoglucosan and acetonitrile. BBOA includes several very large plumes from regional fires and likely also some refuse burning.

  17. "OZONE SOURCE APPORTIONMENT IN CMAQ'

    EPA Science Inventory

    Ozone source attribution has been used to support various policy purposes including interstate transport (Cross State Air Pollution Rule) by U.S. EPA and ozone nonattainment area designations by State agencies. Common scientific applications include tracking intercontinental tran...

  18. 03 SOURCE APPORTIONMENT/RECEPTOR MODELING:OBM FOCUS

    EPA Science Inventory

    Source apportionment (receptor) models are mathematical procedures for identifying and quantifying the sources of ambient air pollutants and their effects at a site (the receptor), primarily on the basis of species concentration measurements at the receptor, and generally without...

  19. Source apportionment of atmospheric particles in the UK and Pakistan

    SciTech Connect

    Smith, D.J.T.; Harrison, R.M.; Luhana, L.

    1995-12-31

    Intensive seasonal sampling was undertaken at urban and rural locations throughout Birmingham (UK). Dichotomous Stacked Filter Units (DSFUS) were run simultaneously with hi-vol samplers. DSFU filters were analyzed for nineteen metal species, ammonium and various anions. Hi-vol samplers were modified in order to collect particulate and vapor phase PAHs by means of filter papers and polyurethane foam plugs. Eighteen PAH species were determined by reversed-phase HPLC. Filter portions were forwarded to the University of Aveiro for analysis of elemental and organic carbon. Hi-vol air sampling equipment was run at three sites in Lahore (Pakistan) for over a year. Selected metals, anions and ammonium were quantified, along with eighteen species of particle-associated PAH. Chemical source apportionment of both the Birmingham and Lahore aerosol loads was completed using multivariate analysis. Metals and anionic data were utilized, along with organic concentrations and meteorological data. This technique typically enabled six major air pollution source categories to be identified, along with the quantitative contributions of pollutant species to each source group. The combination of measurements of PAH and inorganic pollutants proved to be a far more powerful tracer of emission sources than PAH data alone. The largest contribution to aerosol mass in the coarse sized fraction in Birmingham was observed to be soil. Whereas in the fine sized fraction major contributors are vehicular/road dust followed by secondary aerosol formation plus oil combustion. Multivariate analysis of the Lahore data revealed similar source categories to those found in Birmingham. The largest contribution to aerosol mass at all three Punjabi sites was soil. This source is followed by metallurgical processes, vehicular emissions and refuse burning.

  20. Calibration method for a photoacoustic system for real time source apportionment of light absorbing carbonaceous aerosol based on size distribution measurements

    NASA Astrophysics Data System (ADS)

    Utry, Noemi; Ajtai, Tibor; Pinter, Mate; Orvos, Peter I.; Szabo, Gabor; Bozoki, Zoltan

    2016-04-01

    In this study, we introduce a calibration method with which sources of light absorbing carbonaceous particulate matter (LAC) can be apportioned in real time based on multi wavelength optical absorption measurements with a photoacoustic system. The method is primary applicable in wintry urban conditions when LAC is dominated by traffic and biomass burning. The proposed method was successfully tested in a field campaign in the city center of Szeged, Hungary during winter time where the dominance of traffic and wood burning aerosol has been experimentally demonstrated earlier. With the help of the proposed calibration method a relationship between the measured Aerosol Angström Exponent (AAE) and the number size distribution can be deduced. Once the calibration curve is determined, the relative strength of the two pollution sources can be deduced in real time as long as the light absorbing fraction of PM is exclusively related to traffic and wood burning. This assumption is indirectly confirmed in the presented measurement campaign by the fact that the measured size distribution is composed of two unimodal size distributions identified to correspond to traffic and wood burning aerosols. The proposed method offers the possibility of replacing laborious chemical analysis with simple in-situ measurement of aerosol size distribution data.

  1. Radiocarbon based source apportionment of black carbon in the form of PM10 elemental carbon aerosol particles at the Zeppelin Observatory, Svalbard

    NASA Astrophysics Data System (ADS)

    Winiger, Patrik; Andersson, August; Espen Yttri, Karl; Tunved, Peter; Gustafsson, Örjan

    2015-04-01

    Black carbon (BC) aerosol particles are formed from incomplete combustion of fossil fuel and biomass. Transported into the Arctic, they potentially contributes to climate warming. However, there are still large uncertainties related to the climate effects of BC, including aspects of radiative properties, mixing state of the particles, transport, atmospheric lifetime and sources. The current study aims to reduce source uncertainties by applying a top-down (observational) source-diagnostic isotope approach and comparing these to bottom-up (modeling) emission inventories to better constrain the source types and source regions. The use of natural abundance radiocarbon (Δ14C) is a powerful tool to distinguish between fossil (void of 14C) and biomass (contemporary 14C) combustion sources. Due to the well-defined end-members, 14C-measurements (alone) provide high precision (

  2. Source Apportionment of Particulate Matter Sampled in Cape Verde

    NASA Astrophysics Data System (ADS)

    Marta Almeida, Susana; Almeida-Silva, Marina; Pio, Casimiro; Nunes, Teresa; Cardoso, João; Cerqueira, Mário; Reis, Miguel; Chaves, Paula Cristina; Taborda, Ana

    2013-04-01

    Due to its geographical position, Cape Verde is highly affected by the transport of dust from the Sahara desert. Consequently, very high concentrations of particles are registered in this archipelago, being essential to elucidate the role that Saharan dust may play in the degradation of Cape Verde air quality, human health, wellbeing, visibility, tourism and economy. The objective of this study was to identify the main sources and origins of particles sampled in Cape Verde. PM10 was sampled during 2011 and chemical characterization of particles was performed by Neutron Activation Analysis and Particle Induced X-ray Emission for elemental measurements, by Ion Chromatography for the determination of water soluble ions and by a Thermal-optical system for the measurement of carbonaceous aerosol. Source apportionment was performed by integrating Positive Matrix Factorization and Backward Trajectory Analysis. Results showed that in average 68% of the PM10 mass in Cape Verde had a natural origin, being 48% associated with the soil and 20% associated with the sea. During the transport of dust from the Sahara desert the contribution of mineral aerosol increased significantly (69% during periods affected by trajectories provided from Sahara desert versus 13% during periods affected by local sources).

  3. Source Apportionment of Atmospheric Mercury Using Positive Matrix Factorization

    NASA Astrophysics Data System (ADS)

    Richards, L. M.; Perry, K. D.; Abbott, M. L.

    2008-12-01

    A growing problem in the western United States is the widespread contamination of remote lakes by the atmospheric transport and deposition of mercury. Because methylmercury is known to bioaccumulate within the food chain, even small amounts of mercury introduced into an aquatic ecosystem can result in fish that are unsuitable for human consumption. The problem is complex because many natural and anthropogenic sources of mercury exist within the western United States (e.g., coal combustion, cement production, wildfires, mining activities, and emissions from naturally enriched soils and geothermal areas). Mercury can also be transported intercontinental distances (e.g., Asian coal combustion) under appropriate meteorological conditions. Thus, any mercury source apportionment study must be able to distinguish between these disparate source types. In this study, we measured gaseous elemental mercury (GEM), reactive gaseous mercury (RGM), and particulate mercury (HgP) with a Tekran system near Salmon Falls Creek Reservoir in south-central Idaho. These measurements were made during a series of one-month-long, intensive operation periods (IOPs) in the winter, spring, and summer of 2008. In each IOP, we also made coincident size- and time-resolved aerosol elemental composition measurements using an 8-stage rotating drum impactor and synchrotron X-ray fluorescence (SXRF) analysis. The SXRF analysis provided aerosol elemental concentration measurements with 3-hour time resolution. The Positive Matrix Factorization (PMF) receptor model was applied to the high-resolution, aerosol elemental composition data from each IOP to determine the temporal variability of the contributing source types based on the calculated source profiles. A multiple linear regression (MLR) technique was then used to apportion the measured mercury concentrations to the source types identified by the PMF analysis.

  4. Source apportionment of 1 h semi-continuous data during the 2005 Study of Organic Aerosols in Riverside (SOAR) using positive matrix factorization

    NASA Astrophysics Data System (ADS)

    Eatough, Delbert J.; Grover, Brett D.; Woolwine, Woods R.; Eatough, Norman L.; Long, Russell; Farber, Robert

    Positive matrix factorization (PMF2) was used to elucidate sources of fine particulate material (PM 2.5) for a study conducted during July and August 2005, in Riverside, CA. One-hour averaged semi-continuous measurements were made with a suite of instruments to provide PM 2.5 mass and chemical composition data. Total PM 2.5 mass concentrations (non-volatile plus semi-volatile) were measured with an R&P filter dynamic measurement system (FDMS TEOM) and a conventional TEOM monitor was used to measure non-volatile mass concentrations. PM 2.5 chemical species monitors included a dual-oven Sunset monitor to measure both non-volatile and semi-volatile carbonaceous material, an ion chromatographic-based monitor to measure sulfate and nitrate and an Anderson Aethalometer to measure black carbon (BC). Gas phase data including CO, NO 2, NO x and O 3 were also collected during the sampling period. In addition, single-particle measurements were made using aerosol time-of-flight mass spectrometry (ATOFMS). Twenty different single-particle types consistent with those observed in previous ATOFMS studies in Riverside were identified for the PMF2 analysis. Finally, time-of-flight aerosol mass spectrometry (ToF-AMS) provided data on markers of primary and secondary organic aerosol. Two distinct PMF2 analyses were performed. In analysis 1, all the data except for the ATOFMS and ToF-AMS data were used in an initial evaluation of sources at Riverside during the study. PMF2 was able to identify six factors from the data set corresponding to both primary and secondary sources, primarily from automobile emissions, diesel emissions, secondary nitrate formation, a secondary photochemical associated source, organic emissions and Basin transported pollutants. In analysis 2, the ATOFMS and ToF-AMS data were included in the analysis. In the second analysis, PMF2 was able to identify 16 factors with a variety of both primary and secondary factors being identified, corresponding to both primary

  5. Source apportionment using reconstructed mass calculations.

    PubMed

    Siddique, Naila; Waheed, Shahida

    2014-01-01

    A long-term study was undertaken to investigate the air quality of the Islamabad/Rawalpindi area. In this regard fine and coarse particulate matter were collected from 4 sites in the Islamabad/Rawalpindi region from 1998 to 2010 using Gent samplers and polycarbonate filters and analyzed for their elemental composition using the techniques of Neutron Activation Analysis (NAA), Proton Induced X-ray Emission/Proton Induced Gamma-ray Emission (PIXE/PIGE) and X-ray Fluorescence (XRF) Spectroscopy. The elemental data along with the gravimetric measurements and black carbon (BC) results obtained by reflectance measurement were used to approximate or reconstruct the particulate mass (RCM) by estimation of pseudo sources such as soil, smoke, sea salt, sulfate and black carbon or soot. This simple analysis shows that if the analytical technique used does not measure important major elements then the data will not be representative of the sample composition and cannot be further utilized for source apportionment studies or to perform transboundary analysis. In this regard PIXE/PIGE and XRF techniques that can provide elemental compositional data for most of the major environmentally important elements appear to be more useful as compared to NAA. Therefore %RCM calculations for such datasets can be used as a quality assurance (QA) measure to treat data prior to application of chemometrical tools such as factor analysis (FA) or cluster analysis (CA). PMID:24345244

  6. Source apportionment of particulate matter in a large city of southeastern Po Valley (Bologna, Italy).

    PubMed

    Tositti, L; Brattich, E; Masiol, M; Baldacci, D; Ceccato, D; Parmeggiani, S; Stracquadanio, M; Zappoli, S

    2014-01-01

    This study reports the results of an experimental research project carried out in Bologna, a midsize town in central Po valley, with the aim at characterizing local aerosol chemistry and tracking the main source emissions of airborne particulate matter. Chemical speciation based upon ions, trace elements, and carbonaceous matter is discussed on the basis of seasonal variation and enrichment factors. For the first time, source apportionment was achieved at this location using two widely used receptor models (principal component analysis/multi-linear regression analysis (PCA/MLRA) and positive matrix factorization (PMF)). Four main aerosol sources were identified by PCA/MLRA and interpreted as: resuspended particulate and a pseudo-marine factor (winter street management), both related to the coarse fraction, plus mixed combustions and secondary aerosol largely associated to traffic and long-lived species typical of the fine fraction. The PMF model resolved six main aerosol sources, interpreted as: mineral dust, road dust, traffic, secondary aerosol, biomass burning and again a pseudo-marine factor. Source apportionment results from both models are in good agreement providing a 30 and a 33% by weight respectively for PCA-MLRA and PMF for the coarse fraction and 70% (PCA-MLRA) and 67% (PMF) for the fine fraction. The episodic influence of Saharan dust transport on PM10 exceedances in Bologna was identified and discussed in term of meteorological framework, composition, and quantitative contribution. PMID:23828727

  7. Source apportionment in oil spill remediation.

    PubMed

    Muñoz, Jorge; Mudge, Stephen M; Loyola-Sepulveda, Rodrigo; Muñoz, Gonzalo; Bravo-Linares, Claudio

    2012-05-01

    A pipe rupture during unloading led to a spillage of 350-700 tonnes of Caño Limon, a light sweet crude oil, into San Vicente Bay in 2007. Initial clean-up methods removed the majority of the oil from the sandy beaches although some oil remained on the rocky shores. It was necessary for the responsible party to clean the spilled oil even though at this location there were already crude oil hydrocarbons from previous industrial activity. A biosolvent based on vegetable oil derivatives was used to solubilise the remaining oil and a statistical approach to source apportionment was used to determine the efficacy of the cleaning. Sediment and contaminated rock samples were taken prior to cleaning and again at the same locations two days after application of the biosolvent. The oil was extracted using a modified USEPA Method 3550B. The alkanes were quantified together with oil biomarkers on a GC-MS. The contribution that Caño Limon made to the total oil hydrocarbons was calculated from a Partial Least Squares (PLS) analysis using Caño Limon crude oil as the source. By the time the biosolvent was applied, there had already been some attenuation of the oil with all alkanes source of the oil in this case and the contribution that Caño Limon made to the total oil ranged from 0% to 74%. The total hydrocarbon concentrations were lower after cleaning indicating an efficacy of 90% although the reduction in Caño Limon oil was smaller. This was sufficient to make further remediation unnecessary. PMID:22588176

  8. PM10 source apportionment in California's San Joaquin valley

    NASA Astrophysics Data System (ADS)

    Chow, Judith C.; Watson, John G.; Lowenthal, Douglas H.; Solomon, Paul A.; Magliano, Karen L.; Ziman, Steven D.; Willard Richards, L.

    A PM10 (particulate matter with aerodynamic diameter equal to or less than 10 μm) aerosol study was carried out at six sites in California's San Joaquin Valley (SJV) from 14 June 1988 to 9 June 1989, as part of the 1988-1989 Valley Air Quality Study (VAQS). Concentrations of PM10 and PM2.5 (particles with aerodynamic diameters equal to or less than 2.5 μm) mass, organic and elemental carbon, nitrate, sulfate, ammonium and elements were determined in 24-h aerosol samples collected at three urban (Stockton, Fresno, Bakersfield) and three non-urban (Crows Landing, Fellows, Kern Wildlife Refuge) locations during this period. The sources which contributed to ambient concentrations of PM10 were determined by applying the Chemical Mass Balance (CMB) receptor model using the source profiles determined specifically for that study area. The VAQS data indicates the federal 24-h PM10 standard of 150 μg m -3 was exceeded at four out of the six sites and for reasons which differ by season and by spatial region of influence. The annual average source contributions to the PM10 at Bakersfield, the site with the highest annual average, were 54% from primary geological material, 15% from secondary ammonium nitrate, 10% from primary motor vehicle exhaust, 8% from primary construction; the remaining 4% was unexplained. The results of the source apportionment at all sites show that geological contributions (fugitive dust from tilling, roadways and construction) are largest in summer and fall months, while secondary ammonium nitrate contributions (deriving from direct emissions of ammonia and oxides of nitrogen from agricultural activities and engine exhaust) are largest during winter months.

  9. Source apportionment of size resolved particulate matter at a European air pollution hot spot.

    PubMed

    Pokorná, P; Hovorka, J; Klán, M; Hopke, P K

    2015-01-01

    Positive Matrix Factorization-PMF was applied to hourly resolved elemental composition of fine (PM0.15-1.15) and coarse (PM1.15-10) aerosol particles to apportion their sources in the airshed of residential district, Ostrava-Radvanice and Bartovice in winter 2012. Multiple-site measurement by PM2.5 monitors complements the source apportionment. As there were no statistical significant differences amongst the monitors, the source apportionment derived for the central site data is expected to apply to whole residential district. The apportioned sources of the fine aerosol particles were coal combustion (58.6%), sinter production-hot phase (22.9%), traffic (15%), raw iron production (3.5%), and desulfurization slag processing (<0.5%) whilst road dust (47.3%), sinter production-cold phase (27.7%), coal combustion (16.8%), and raw iron production (8.2%) were resolved being sources of the coarse aerosol particles. The shape and elemental composition of size-segregated aerosol airborne-sampled by an airship aloft presumed air pollution sources helped to interpret the PMF solution. PMID:25260163

  10. Source apportionment of particulate matter in Denmark

    NASA Astrophysics Data System (ADS)

    Moenster, J.; Glasius, M.; Nielsen, O. J.; Bilde, M.; Jensen, F. P.

    2005-12-01

    Atmospheric particulate matter (PM) has received considerable attention over the last decade as an important component of air pollution, particularly due to its health effects on the exposed population. Typically the mass of particles with diameters smaller that 10 μm (PM10) has been used in large cohort studies to estimate health effects such as increase in hospitalization rate, asthma attacks and premature deaths. Particles smaller than 2.5 μm (PM2.5) and ultra fine particles have been used in various epidemiological studies and correlations between exposure to fine and ultra fine particles and health effects have been found. Limits of acceptable concentrations of PM10, PM2.5 and some carcinogenic species have been made, and it is important to find the origin of the particulate matter to prevent exceeds of these limits. This can be done by measuring particle mass, organic/inorganic fractions of particles, the chemical components and other relevant factors, and then use receptor modeling for source apportionment of the particulate matter. We have done measurements at street level and urban background in Copenhagen, Denmark, to determine the origin of different sizes of particulate matter and the toxic organic compounds connected to these particles. We also did measurements in a small village with less traffic and more residential wood combustion for a comparison between traffic and wood combustion generated pollution. Our results show a significant amount of particulate matter coming from non local sources and are dominated by long-range transported inorganic salts. The amount of these is highly depended on the wind direction and thus on the origin of the wind plume. The origin of the carcinogenic organic compound benzo(a)pyrene was found to be local combustion sources. To prevent events of high particulate matter concentration in Copenhagen, Denmark, a reduction of emission from the local traffic will only lead to a minor effect, since the majority of the

  11. Source apportionment of light absorbing WSOC in South Asian outflow

    NASA Astrophysics Data System (ADS)

    Bosch, Carme; Kirillova, Elena; Andersson, August; Kruså, Martin; Budhavant, Krishnakant; Tiwari, Suresh; Gustafsson, Örjan

    2013-04-01

    was 0.38±0.09 m2g-1. MAE increased sharply from long to short wavelengths. This evidences that WSOC is constituted of compounds that are light absorbing near ultraviolet wavelengths. WSOC in Maldives would contribute 19% of the total absorption at wavelengths below 400 nm. Since a substantially absorbing effect by WSOC has been shown here and in other studies, knowledge about WSOC sources is needed. The sources of WSOC in atmospheric aerosols, which may be both of primary and secondary origins, are in general poorly constrained. Biomass burning is a significant primary source of WSOC whereas secondary organic aerosol formation also takes place. Isotopic measurements (stable (δ13C) and radiocarbon (Δ14C)) were applied to inform on the origin of WSOC for both sites. Δ14C allows quantitative apportionment between fossil fuel versus biogenic and biomass combustion sources. δ13C is informative of the atmospheric processing of WSOC during long-range transport of aerosols.

  12. Source apportionment of fine atmospheric particles in Marseille: a one year study

    NASA Astrophysics Data System (ADS)

    Marchand, Nicolas; Salameh, Dalia; Detournay, Anais; Wortham, Henri; Jaffrezo, Jean-Luc; Piot, Christine; Armengaud, Alexandre; Piga, Damien; Parra, Michael; Deveze, Magali

    2013-04-01

    Marseille is the second most populated city in France with more than one million inhabitants. With traffic of about 88 million tons (Mt) in 2011, Marseille is also the most important port of the Mediterranean Sea, and also in the vicinity of the large petrochemical and industrial area of Fos-Berre, located 40 km northwest of the metropolitan area. For these reasons, Marseille area represents a challenging case study for source apportionment exercises, combining an active photochemistry and multiple emission sources, including fugitive emissions from industrial sources and shipping. In order to develop strategies for controlling and reducing air pollution, there is a need of source apportionment studies in order to better understand the influence of the different sources of aerosol particles. Within the framework of the EU-MED APICE project (Common Mediterranean strategy and local practical Actions for the mitigation of Port, Industries and Cities Emissions ; www.apice-project.eu), sources of atmospheric particles in Marseille were evaluated for a one-year period by a long monitoring campaign conducted at two sampling sites. PM2.5 were collected continuously on a 24h-basis in an urban background site from July 2011 to July 2012 and on a 48h-basis for the Eastern dock from November 2011 to July 2012 using high volume samplers (DA80) operating at a flow rate of 30m3 h-1. In this work, two different source apportionment models were used to explain the chemical observations, and to investigate the sources of organic aerosol in Marseille. Two sources apportionment models were used and combined to quantify the contribution of the main aerosol particles sources: CMB (Chemical Mass Balance) and PMF (Positive Matrix Factorization). Both models were used with organic molecular markers and metals/trace elements. Both approaches are able to identify major sources, the combination of these two commonly used receptor models offer interesting perspective, especially when the

  13. Optimized variable source-profile approach for source apportionment

    NASA Astrophysics Data System (ADS)

    Marmur, Amit; Mulholland, James A.; Russell, Armistead G.

    An expanded chemical mass balance (CMB) approach for PM 2.5 source apportionment is presented in which both the local source compositions and corresponding contributions are determined from ambient measurements and initial estimates of source compositions using a global-optimization mechanism. Such an approach can serve as an alternative to using predetermined (measured) source profiles, as traditionally used in CMB applications, which are not always representative of the region and/or time period of interest. Constraints based on ranges of typical source profiles are used to ensure that the compositions identified are representative of sources and are less ambiguous than the factors/sources identified by typical factor analysis (FA) techniques. Gas-phase data (SO 2, CO and NO y) are also used, as these data can assist in identifying sources. Impacts of identified sources are then quantified by minimizing the weighted-error between apportioned and measured levels of the fitting species. This technique was applied to a dataset of PM 2.5 measurements at the former Atlanta Supersite (Jefferson Street site), to apportion PM 2.5 mass into nine source categories. Good agreement is found when these source impacts are compared with those derived based on measured source profiles as well as those derived using a current FA technique, Positive Matrix Factorization. The proposed method can be used to assess the representativeness of measured source-profiles and to help identify those profiles that may be in significant error, as well as to quantify uncertainties in source-impact estimates, due in part to uncertainties in source compositions.

  14. Rocky Mountain National Park reduced nitrogen source apportionment

    NASA Astrophysics Data System (ADS)

    Thompson, Tammy M.; Rodriguez, Marco A.; Barna, Michael G.; Gebhart, Kristi A.; Hand, Jennifer L.; Day, Derek E.; Malm, William C.; Benedict, Katherine B.; Collett, Jeffrey L., Jr.; Schichtel, Bret A.

    2015-05-01

    Excess wet and dry deposition of nitrogen-containing compounds are a concern at a number of national parks. The Rocky Mountain Atmospheric Nitrogen and Sulfur Study Part II (RoMANS II) campaign was conducted from November 2008 to November 2009 to characterize the composition of reactive nitrogen and sulfur deposited in Rocky Mountain National Park (RMNP). RoMANS II identified reduced nitrogen as the major contributor to reactive nitrogen deposition in RMNP, making up over 50% of the total. Motivated by this finding, the particulate source apportionment technology within the Comprehensive Air Quality Model with extensions was used here to estimate source apportionment of reduced nitrogen concentrations at RMNP. Source apportionment results suggest that approximately 40% of reduced nitrogen deposition to RMNP comes from ammonia sources within Colorado. However, the model evaluation also suggests that this number could be underrepresenting ammonia sources in eastern Colorado due to the difficulty of capturing upslope airflow on the eastern side of the Continental Divide with meteorological models. Emissions from California, the western model boundary, and the Snake River Valley in Idaho, the next three most influential sources, contribute approximately 15%, 8%, and 7%, respectively, to total reduced nitrogen measured in RMNP. Within Colorado, about 61%, 26%, and 13% of the total Colorado contribution comes from sources to the east of the Continental Divide, sources to the west of the Continental Divide, and from the park itself.

  15. Sensitivity of fine sediment source apportionment to mixing model assumptions

    NASA Astrophysics Data System (ADS)

    Cooper, Richard; Krueger, Tobias; Hiscock, Kevin; Rawlins, Barry

    2015-04-01

    Mixing models have become increasingly common tools for quantifying fine sediment redistribution in river catchments. The associated uncertainties may be modelled coherently and flexibly within a Bayesian statistical framework (Cooper et al., 2015). However, there is more than one way to represent these uncertainties because the modeller has considerable leeway in making error assumptions and model structural choices. In this presentation, we demonstrate how different mixing model setups can impact upon fine sediment source apportionment estimates via a one-factor-at-a-time (OFAT) sensitivity analysis. We formulate 13 versions of a mixing model, each with different error assumptions and model structural choices, and apply them to sediment geochemistry data from the River Blackwater, Norfolk, UK, to apportion suspended particulate matter (SPM) contributions from three sources (arable topsoils, road verges and subsurface material) under base flow conditions between August 2012 and August 2013 (Cooper et al., 2014). Whilst all 13 models estimate subsurface sources to be the largest contributor of SPM (median ~76%), comparison of apportionment estimates reveals varying degrees of sensitivity to changing prior parameter distributions, inclusion of covariance terms, incorporation of time-variant distributions and methods of proportion characterisation. We also demonstrate differences in apportionment results between a full and an empirical Bayesian setup and between a Bayesian and a popular Least Squares optimisation approach. Our OFAT sensitivity analysis reveals that mixing model structural choices and error assumptions can significantly impact upon fine sediment source apportionment results, with estimated median contributions in this study varying by up to 21% between model versions. Users of mixing models are therefore strongly advised to carefully consider and justify their choice of model setup prior to conducting fine sediment source apportionment investigations

  16. Review: Particle number size distributions from seven major sources and implications for source apportionment studies

    NASA Astrophysics Data System (ADS)

    Vu, Tuan V.; Delgado-Saborit, Juana Maria; Harrison, Roy M.

    2015-12-01

    The particle number size distribution (PNSD) of airborne particles not only provides us with information about sources and atmospheric processing of particles, but also plays an important role in determining regional lung dose. As a result, urban particles and their size distributions have received much attention with a rapid increase of publications in recent years. The object of this review is to synthesise and analyse existing knowledge on particles in urban environments with a focus on their number concentration and size distribution. This study briefly reviews the characterization of PNSD from seven major sources of urban particles including traffic emissions, industrial emissions, biomass burning, cooking, transported aerosol, marine aerosol and nucleation. It then discusses atmospheric physical processes such as coagulation or condensation which have a strong influence on PNSD. Finally, the implications of PNSD datasets for source modelling are briefly discussed. Based on this review, it is concluded that the concentrations, modal structures and temporal patterns of urban particles are strongly influenced by traffic emissions, which are identified as the main source of particle number in urban environments. Information derived from particle number size distributions is beginning to play an important role in source apportionment studies.

  17. Source Contributions to Wintertime Elemental and Organic Carbon in the Western Arctic Based on Radiocarbon and Tracer Apportionment.

    PubMed

    Barrett, T E; Robinson, E M; Usenko, S; Sheesley, R J

    2015-10-01

    To quantify the contributions of fossil and biomass sources to the wintertime Arctic aerosol burden source apportionment is reported for elemental (EC) and organic carbon (OC) fractions of six PM10 samples collected during a wintertime (2012-2013) campaign in Barrow, AK. Radiocarbon apportionment of EC indicates that fossil sources contribute an average of 68 ± 9% (0.01-0.07 μg m(-3)) in midwinter decreasing to 49 ± 6% (0.02 μg m(-3)) in late winter. The mean contribution of fossil sources to OC for the campaign was stable at 38 ± 8% (0.04-0.32 μg m(-3)). Samples were also analyzed for organic tracers, including levoglucosan, for use in a chemical mass balance (CMB) source apportionment model. The CMB model was able to apportion 24-53% and 99% of the OC and EC burdens, respectively, during the campaign, with fossil OC contributions ranging from 25 to 74% (0.02-0.09 μg m(-3)) and fossil EC contributions ranging from 73 to 94% (0.03-0.07 μg m(-3)). Back trajectories identified two major wintertime source regions to Barrow: the Russian and North American Arctic. Atmospheric lifetimes of levoglucosan, ranging from 50 to 320 h, revealed variability in wintertime atmospheric processing of this biomass burning tracer. This study allows for unambiguous apportionment of EC to fossil fuel and biomass combustion sources and intercomparison with CMB modeling. PMID:26325404

  18. Enterococcus and Escherichia coli fecal source apportionment with microbial source tracking genetic markers - is it feasible?

    EPA Science Inventory

    Fecal pollution is measured in surface waters using culture-based measurements of enterococci and Escherichia coli bacteria. Source apportionment of these two fecal indicator bacteria is an urgent need for prioritizing remediation efforts and quantifying health risks associated...

  19. Radiocarbon-derived source apportionment of fine carbonaceous aerosols before, during, and after the 2014 Asia-Pacific Economic Cooperation (APEC) summit in Beijing, China

    NASA Astrophysics Data System (ADS)

    Liu, Junwen; Mo, Yangzhi; Li, Jun; Liu, Di; Shen, Chengde; Ding, Ping; Jiang, Haoyu; Cheng, Zhineng; Zhang, Xiangyun; Tian, Chongguo; Chen, Yingjun; Zhang, Gan

    2016-04-01

    The Asia-Pacific Economic Cooperation (APEC) summit took place in Beijing, China, 5-11 November 2014, during which numerous measures were performed to control the air pollution, and consequently, the sky of Beijing was so clean that the public called it "APEC blue." The concentrations before, during, and after the APEC summit are 14.4 ± 6.81 µg C/m3, 6.66 ± 2.99 µg C/m3, and 32.3 ± 10.6 µg C/m3, respectively, for organic carbon (OC), and 2.27 ± 1.17 µg C/m3, 0.76 ± 0.52 µg C/m3, and 4.99 ± 1.74 µg C/m3, respectively, for elemental carbon (EC). We quantify the contributions of fossil and nonfossil sources to the OC and EC using radiocarbon. Results show that the contribution of nonfossil sources is 56 ± 1% (before APEC), 61 ± 1% (during APEC), and 48 ± 1% (after APEC), respectively, for OC, and 36 ± 4% (before APEC), 46 ± 1% (during APEC), and 33 ± 4% (after APEC), respectively, for EC. Comparing to the period before APEC, 70% and 60% of fossil EC and OC and 60% and 50% of nonfossil EC and OC are reduced, respectively, implying that the control on the nonfossil sources has considerable contribution to the good air quality in Beijing. Both EC and OC mass loadings during the APEC summit would have increased by 60% if the biomass-burning activities were not taken into account for control. In such a case, the atmospheric visibility would decrease 20% at least and the blue sky thereby would likely not have been visible during the summit.

  20. Indoor source apportionment in urban communities near industrial sites

    NASA Astrophysics Data System (ADS)

    Tunno, Brett J.; Dalton, Rebecca; Cambal, Leah; Holguin, Fernando; Lioy, Paul; Clougherty, Jane E.

    2016-08-01

    Because fine particulate matter (PM2.5) differs in chemical composition, source apportionment is frequently used for identification of relative contributions of multiple sources to outdoor concentrations. Indoor air pollution and source apportionment is often overlooked, though people in northern climates may spend up to 90% of their time inside. We selected 21 homes for a 1-week indoor sampling session during summer (July to September 2011), repeated in winter (January to March 2012). Elemental analysis was performed using inductively-coupled plasma mass spectrometry (ICP-MS), and factor analysis was used to determine constituent grouping. Multivariate modeling was run on factor scores to corroborate interpretations of source factors based on a literature review. For each season, a 5-factor solution explained 86-88% of variability in constituent concentrations. Indoor sources (i.e. cooking, smoking) explained greater variability than did outdoor sources in these industrial communities. A smoking factor was identified in each season, predicted by number of cigarettes smoked. Cooking factors were also identified in each season, explained by frequency of stove cooking and stovetop frying. Significant contributions from outdoor sources including coal and motor vehicles were also identified. Higher coal and secondary-related elemental concentrations were detected during summer than winter. Our findings suggest that source contributions to indoor concentrations can be identified and should be examined in relation to health effects.

  1. Source-apportionment and model evaluation: experiences with the EMEP SOA model

    NASA Astrophysics Data System (ADS)

    Simpson, D.; Yttri, K. E.

    2009-04-01

    The EMEP MSC-W chemical transport model (Simpson et al., 2003) has been successfully used for the prediction of photochemical oxidants and various inorganic aerosol components (sulphate, nitrate, ammonium) for many years. The model generally performs well for such species, as should be expected for compounds whose emission sources and chemistry are fairly well know. For carbonaceous particulate matter (PCM) however the model has been found to give very different results in different parts of Europe, with typically poor performance in southern Europe, but rather good results in Northern Europe (Simpson et al., 2007). Earlier comparison with the results of source-apportionment studies from the CARBOSOL project (Gelencser et al., 2007, Simpson et al., 2007) has shown that the poor performance in southern Europe can partly be ascribed to difficulties with emissions from residential wood-burning, and partly due to an underestimate of the secondary organic aerosol (SOA) component. Such difficulties are expected for organic aerosols, a subject where the basic science is only partially understood, and where new experimental results continually lead to revisions in existing ideas concerning sources and formation mechanisms (e.g. Hallquist et al., 2009). In such a situation, it is essential that model results are evaluated as thoroughly as possible, and that where possible the various components of organic aerosol can be evaluated separately. A number of source-apportionment (SA) studies have recently become available in Europe, in which data on elemental carbon (EC), organic carbon (OC), 14C, levoglucosan, and various markers of primary organic carbon (cellulose, sugars/sugar-alcohols) have allowed estimates of various sources of carbonaceous particulate matter (PCM). As well as CARBOSOL, these studies include various sites in Switzerland (e.g. Lanz et al., 2008, Szidat et al., 2006), data are available from Gothenburg in Sweden (Szidat et al., 2008) and from southern

  2. Source apportionment of volatile organic compounds in Tehran, Iran.

    PubMed

    Sarkhosh, Maryam; Mahvi, Amir Hossein; Yunesian, Masud; Nabizadeh, Ramin; Borji, Saeedeh Hemmati; Bajgirani, Ali Ghiami

    2013-04-01

    Identifying the sources of volatile organic compounds (VOCs) is key issue to reducing ground-level ozone and PAN. A multivariate receptor model (Unmix) was used for the determination of the contributions of VOCs sources in Tehran-Iran. Concentrations of ambient C2-C10 VOCs were measured continuously and online at the center of Tehran city during the winter of 2012. A high correlation coefficient existed between measured and predicted values (R (2) = 0.99), indicating that the data were well modeled. Five possible VOCs source categories were identified and mobile sources such as vehicle exhaust (61 %) and fuel evaporation (12 %) more than half of the total VOC concentration. City gas and CNG sources, biogenic source, and industrial solvent source categories accounted for 17 %, 8 % and 2 % of the total VOC, respectively. Result showed Unmix for VOCs source apportionment can be used to analyze and generate air pollution control strategies and policies. PMID:23283536

  3. An integrated PM2.5 source apportionment study: Positive Matrix Factorisation vs. the chemical transport model CAMx

    NASA Astrophysics Data System (ADS)

    Bove, M. C.; Brotto, P.; Cassola, F.; Cuccia, E.; Massabò, D.; Mazzino, A.; Piazzalunga, A.; Prati, P.

    2014-09-01

    Receptor and Chemical Transport Models are commonly used tools in source apportionment studies, even if different expertise is required. We describe an experiment using both approaches to apportion the PM2.5 (i.e., particulate matter with aerodynamic diameters below 2.5 μm) sources in the city of Genoa (Italy). A sampling campaign was carried out to collect PM2.5 samples daily for approximately six month during 2011 in three sites. The subsequent compositional analyses included the speciation of elements, major ions and both organic and elemental carbon; these data produced a large database for receptor modelling through Positive Matrix Factorisation (PMF). In the same period, a meteorological and air quality modelling system was implemented based on the mesoscale numerical weather prediction model WRF and the chemical transport model CAMx to obtain meteorological and pollutant concentrations up to a resolution of 1.1 km. The source apportionment was evaluated by CAMx over the same period that was used for the monitoring campaign using the Particulate Source Apportionment Technology tool. Even if the source categorisations were changed (i.e., groups of time-correlated compounds in PMF vs. activity categories in CAMx), the PM2.5 source apportionment by PMF and CAMx produced comparable results. The different information provided by the two approaches (e.g., real-world factor profile by PMF and apportionment of a secondary aerosol by CAMx) was used jointly to elucidate the composition and origin of PM2.5 and to develop a more general methodology. When studying the primary and secondary components of PM, the main anthropogenic sources in the area were road transportation, energy production/industry and maritime emissions, accounting for 40%-50%, 20%-30% and 10%-15%, of PM2.5, respectively.

  4. An inter-comparison of PM10 source apportionment using PCA and PMF receptor models in three European sites.

    PubMed

    Cesari, Daniela; Amato, F; Pandolfi, M; Alastuey, A; Querol, X; Contini, D

    2016-08-01

    Source apportionment of aerosol is an important approach to investigate aerosol formation and transformation processes as well as to assess appropriate mitigation strategies and to investigate causes of non-compliance with air quality standards (Directive 2008/50/CE). Receptor models (RMs) based on chemical composition of aerosol measured at specific sites are a useful, and widely used, tool to perform source apportionment. However, an analysis of available studies in the scientific literature reveals heterogeneities in the approaches used, in terms of "working variables" such as the number of samples in the dataset and the number of chemical species used as well as in the modeling tools used. In this work, an inter-comparison of PM10 source apportionment results obtained at three European measurement sites is presented, using two receptor models: principal component analysis coupled with multi-linear regression analysis (PCA-MLRA) and positive matrix factorization (PMF). The inter-comparison focuses on source identification, quantification of source contribution to PM10, robustness of the results, and how these are influenced by the number of chemical species available in the datasets. Results show very similar component/factor profiles identified by PCA and PMF, with some discrepancies in the number of factors. The PMF model appears to be more suitable to separate secondary sulfate and secondary nitrate with respect to PCA at least in the datasets analyzed. Further, some difficulties have been observed with PCA in separating industrial and heavy oil combustion contributions. Commonly at all sites, the crustal contributions found with PCA were larger than those found with PMF, and the secondary inorganic aerosol contributions found by PCA were lower than those found by PMF. Site-dependent differences were also observed for traffic and marine contributions. The inter-comparison of source apportionment performed on complete datasets (using the full range of

  5. Source Apportionment of Elemental Carbon in Beijing, China: Insights from Radiocarbon and Organic Marker Measurements.

    PubMed

    Zhang, Yan-Lin; Schnelle-Kreis, Jürgen; Abbaszade, Gülcin; Zimmermann, Ralf; Zotter, Peter; Shen, Rong-rong; Schäfer, Klaus; Shao, Longyi; Prévôt, André S H; Szidat, Sönke

    2015-07-21

    Elemental carbon (EC) or black carbon (BC) in the atmosphere has a strong influence on both climate and human health. In this study, radiocarbon ((14)C) based source apportionment is used to distinguish between fossil fuel and biomass burning sources of EC isolated from aerosol filter samples collected in Beijing from June 2010 to May 2011. The (14)C results demonstrate that EC is consistently dominated by fossil-fuel combustion throughout the whole year with a mean contribution of 79% ± 6% (ranging from 70% to 91%), though EC has a higher mean and peak concentrations in the cold season. The seasonal molecular pattern of hopanes (i.e., a class of organic markers mainly emitted during the combustion of different fossil fuels) indicates that traffic-related emissions are the most important fossil source in the warm period and coal combustion emissions are significantly increased in the cold season. By combining (14)C based source apportionment results and picene (i.e., an organic marker for coal emissions) concentrations, relative contributions from coal (mainly from residential bituminous coal) and vehicle to EC in the cold period were estimated as 25 ± 4% and 50 ± 7%, respectively, whereas the coal combustion contribution was negligible or very small in the warm period. PMID:26114602

  6. Urban PM source apportionment mapping using microscopic chemical imaging.

    PubMed

    Gertler, Alan W; Moshe, Danny; Rudich, Yinon

    2014-08-01

    To evaluate the health impacts of particulate matter and develop effective pollutant abatement strategies, one needs to know the source contributions to the observed concentrations. The most common approach involves the collection of ambient air samples on filters, laboratory analyses to quantify the chemical composition, and application of receptor modeling methods. This approach is expensive and time consuming and limits the ability to monitor the temporal and spatial impacts from different pollutant sources. An alternative method for apportioning the sources of ambient PM is the application of microscopic chemical imaging (MCI). The MCI method involves measuring individual particle's fluorescence and source attribution is based on the individual particle analysis coupled with identification from a source library. Using this approach, the apportionment of ambient PM can be performed in near real time, which allows for the generation of temporal and spatial maps of pollutant source impacts in an urban area. PMID:24225422

  7. Source apportionment of ambient VOCs in Delhi City.

    PubMed

    Srivastava, Anjali; Sengupta, B; Dutta, S A

    2005-05-01

    Source apportionment using chemical mass balance (CMB) model was carried using a data set of 360 four hourly samples collected at 15 locations of five categories namely residential, commercial, industrial, traffic intersections and petrol pumps during August 2001-July 2002 in Delhi. The results indicate that emissions from diesel internal combustion engines dominate in Delhi. Vehicular exhaust and evaporative emissions also contribute significantly to VOCs in ambient air. Emission of VOCs associated with sewage sludge was also found to contribute to VOCs in Delhi's air. This points to the fact that open defecation and leaking sewage manholes are a problem in all categories of locations. PMID:15862846

  8. Overview of the Lombardy Region (I) Source Apportionment Study

    NASA Astrophysics Data System (ADS)

    Larsen, B. R.

    2009-04-01

    The Lombardia Region (RL) is situated in the central part of the Po Plain (I) where the mesoscale climatological conditions are determined to a high degree by the orographical characteristics of this area. Encirclement from three sides (North, West and South) by the mountain chains contributes greatly to the climatological peculiarities that are related from the physical point of view to the dynamic of the air mass in this region. The adverse anemological regime and the persistence of atmospheric stability result in low wind speeds, inversion of the temperature, and shallow inversion layers. Due to these particular geographical and the meteorological conditions associated with a high population density (9 million inhabitants) and the connected anthropogenic activities, RL is one of Europe's most polluted regions with regard to PM and photochemical smog. The 24 hours EU air quality limit for PM10 of 50 ug/m3 is exceeded up to 180 days per year and the yearly limit of 40 ug/m3 is in breach for most urban/urban background areas. In order to efficiently plan abatement strategies, quantitative information is required on the pollution sources and available emission inventories need to be compared with source apportionment results derived by receptor modeling of the chemical composition of PM10 in ambient air and in source emissions. The European Commission Joint Research Centre (JRC) has embarked on a major integrated project in RL (2006-2010) in collaboration with the air quality authorities (ARPA) to support the design of appropriate air quality and emission reduction strategies in this area. The present paper presents the first results of this project, carried out during typical winter episodes in 2007 at ten measurement stations distributed over the entire RL. The source contributions to PM10 and the associated air toxics (benzo[a]pyrene, Pb, Ni, Cd and As) have been quantified by Chemical Mass Balance and Positive Matrix Factorization based upon the chemical

  9. Source Apportionment of PM2.5 in Delhi, India Using PMF Model.

    PubMed

    Sharma, S K; Mandal, T K; Jain, Srishti; Saraswati; Sharma, A; Saxena, Mohit

    2016-08-01

    Chemical characterization of PM2.5 [organic carbon, elemental carbon, water soluble inorganic ionic components, and major and trace elements] was carried out for a source apportionment study of PM2.5 at an urban site of Delhi, India from January, 2013, to December, 2014. The annual average mass concentration of PM2.5 was 122 ± 94.1 µg m(-3). Strong seasonal variation was observed in PM2.5 mass concentration and its chemical composition with maxima during winter and minima during monsoon. A receptor model, positive matrix factorization (PMF) was applied for source apportionment of PM2.5 mass concentration. The PMF model resolved the major sources of PM2.5 as secondary aerosols (21.3 %), followed by soil dust (20.5 %), vehicle emissions (19.7 %), biomass burning (14.3 %), fossil fuel combustion (13.7 %), industrial emissions (6.2 %) and sea salt (4.3 %). PMID:27209541

  10. Photochemical grid model implementation and application of VOC, NOx, and O3 source apportionment

    EPA Science Inventory

    For the purposes of developing optimal emissions control strategies, efficient approaches are needed to identify the major sources or groups of sources that contribute to elevated ozone (O3) concentrations. Source-based apportionment techniques implemented in photochemical grid m...

  11. SOURCE APPORTIONMENT RESULTS, UNCERTAINTIES, AND MODELING TOOLS

    EPA Science Inventory

    Advanced multivariate receptor modeling tools are available from the U.S. Environmental Protection Agency (EPA) that use only speciated sample data to identify and quantify sources of air pollution. EPA has developed both EPA Unmix and EPA Positive Matrix Factorization (PMF) and ...

  12. Iodine source apportionment in the Malawian diet

    NASA Astrophysics Data System (ADS)

    Watts, M. J.; Joy, E. J. M.; Young, S. D.; Broadley, M. R.; Chilimba, A. D. C.; Gibson, R. S.; Siyame, E. W. P.; Kalimbira, A. A.; Chilima, B.; Ander, E. L.

    2015-10-01

    The aim of this study was to characterise nutritional-I status in Malawi. Dietary-I intakes were assessed using new datasets of crop, fish, salt and water-I concentrations, while I status was assessed for 60 women living on each of calcareous and non-calcareous soils as defined by urinary iodine concentration (UIC). Iodine concentration in staple foods was low, with median concentrations of 0.01 mg kg-1 in maize grain, 0.008 mg kg-1 in roots and tubers, but 0.155 mg kg-1 in leafy vegetables. Freshwater fish is a good source of dietary-I with a median concentration of 0.51 mg kg-1. Mean Malawian dietary-Iodine intake from food, excluding salt, was just 7.8 μg d-1 compared to an adult requirement of 150 μg d-1. Despite low dietary-I intake from food, median UICs were 203 μg L-1 with only 12% defined as I deficient whilst 21% exhibited excessive I intake. Iodised salt is likely to be the main source of dietary I intake in Malawi; thus, I nutrition mainly depends on the usage and concentration of I in iodised salt. Drinking water could be a significant source of I in some areas, providing up to 108 μg d-1 based on consumption of 2 L d-1.

  13. Iodine source apportionment in the Malawian diet.

    PubMed

    Watts, M J; Joy, E J M; Young, S D; Broadley, M R; Chilimba, A D C; Gibson, R S; Siyame, E W P; Kalimbira, A A; Chilima, B; Ander, E L

    2015-01-01

    The aim of this study was to characterise nutritional-I status in Malawi. Dietary-I intakes were assessed using new datasets of crop, fish, salt and water-I concentrations, while I status was assessed for 60 women living on each of calcareous and non-calcareous soils as defined by urinary iodine concentration (UIC). Iodine concentration in staple foods was low, with median concentrations of 0.01 mg kg(-1) in maize grain, 0.008 mg kg(-1) in roots and tubers, but 0.155 mg kg(-1) in leafy vegetables. Freshwater fish is a good source of dietary-I with a median concentration of 0.51 mg kg(-1). Mean Malawian dietary-Iodine intake from food, excluding salt, was just 7.8 μg d(-1) compared to an adult requirement of 150 μg d(-1). Despite low dietary-I intake from food, median UICs were 203 μg L(-1) with only 12% defined as I deficient whilst 21% exhibited excessive I intake. Iodised salt is likely to be the main source of dietary I intake in Malawi; thus, I nutrition mainly depends on the usage and concentration of I in iodised salt. Drinking water could be a significant source of I in some areas, providing up to 108 μg d(-1) based on consumption of 2 L d(-1). PMID:26503697

  14. Iodine source apportionment in the Malawian diet

    PubMed Central

    Watts, M. J.; Joy, E. J. M.; Young, S. D.; Broadley, M. R.; Chilimba, A. D. C.; Gibson, R. S.; Siyame, E. W. P.; Kalimbira, A. A.; Chilima, B.; Ander, E. L.

    2015-01-01

    The aim of this study was to characterise nutritional-I status in Malawi. Dietary-I intakes were assessed using new datasets of crop, fish, salt and water-I concentrations, while I status was assessed for 60 women living on each of calcareous and non-calcareous soils as defined by urinary iodine concentration (UIC). Iodine concentration in staple foods was low, with median concentrations of 0.01 mg kg−1 in maize grain, 0.008 mg kg−1 in roots and tubers, but 0.155 mg kg−1 in leafy vegetables. Freshwater fish is a good source of dietary-I with a median concentration of 0.51 mg kg−1. Mean Malawian dietary-Iodine intake from food, excluding salt, was just 7.8 μg d−1 compared to an adult requirement of 150 μg d−1. Despite low dietary-I intake from food, median UICs were 203 μg L−1 with only 12% defined as I deficient whilst 21% exhibited excessive I intake. Iodised salt is likely to be the main source of dietary I intake in Malawi; thus, I nutrition mainly depends on the usage and concentration of I in iodised salt. Drinking water could be a significant source of I in some areas, providing up to 108 μg d−1 based on consumption of 2 L d−1. PMID:26503697

  15. Quantitative back-trajectory apportionment of sources of particulate sulfate at Big Bend National Park, TX

    NASA Astrophysics Data System (ADS)

    Gebhart, Kristi A.; Schichtel, Bret A.; Barna, Michael G.; Malm, William C.

    As part of the Big Bend Regional Aerosol and Visibility Observational (BRAVO) study, a quantitative back-trajectory-based receptor model, Trajectory Mass Balance (TrMB) was used to estimate source apportionment of particulate sulfur measured at Big Bend National Park, Texas, during July-October 1999. The model was exercised using a number of sets of trajectories generated by three different trajectory models, with three different sets of input gridded meteorology, and tracked for 5, 7, and 10 days back in time. The performance of the TrMB model with the different trajectory inputs was first evaluated against perfluorocarbon tracers and synthetically generated sulfate concentrations from a regional air quality model, both of which had known attributions. These tests were used to determine which trajectories were adequate for the TrMB modeling of measured sulfate concentrations, illustrated the magnitude of the daily uncertainties as compared to the uncertainties in the mean attributions, and demonstrated the value of a robust evaluation process. Depending on trajectories, mean sulfate source apportionment results were 39-50% from Mexico, 7-26% from the eastern US, 12-45% from Texas, and 3-25% from the western US. These ranges were inclusive of the best BRAVO attribution estimates for Mexico, Texas, and the western US, but TrMB underestimated the eastern US contribution as compared to the BRAVO best estimates.

  16. Chemical composition and source apportionment of PM2.5 particles in the Sihwa area, Korea.

    PubMed

    Park, S S; Bae, M S; Kim, Y J

    2001-03-01

    To investigate the chemical characteristics of fine particles in the Sihwa area, Korea, atmospheric aerosol samples were collected using a dichotomous PM10 sampler and two URG PM2.5 cyclone samplers during five intensive sampling periods between February 1998 and February 1999. The Inductively Coupled Plasma (ICP)-Atomic Emission Spectrometry (AES)/ICP-Mass Spectrometry (MS), ion chromatograph (IC), and thermal manganese dioxide oxidation (TMO) methods were used to analyze the trace elements, ionic species, and carbonaceous species, respectively. Backward trajectory analysis, factor analysis, and a chemical mass balance (CMB) model were used to estimate quantitatively source contributions to PM2.5 particles collected in the Sihwa area. The results of PM2.5 source apportionment using the CMB7 receptor model showed that (NH4)2SO4 was, on average, the major contributor to PM2.5 particles, followed by nontraffic organic carbon (OC) emission, NH4NO3, agricultural waste burning, motor vehicle emission, road dust, waste incineration, marine aerosol, and others. Here, the nontraffic OC sources include primary anthropogenic OC emitted from the industrial complex zone, secondary OC, and organic species from distant sources. The source impact of waste incineration emission became significant when the dominant wind directions were from southwest and west sectors during the sampling periods. It was found that PM2.5 particles in the Sihwa area were influenced mainly by both anthropogenic local sources and long-range transport and transformation of air pollutants. PMID:11266103

  17. Chemical characterization and source apportionment of PM2.5 in Beijing: seasonal perspective

    NASA Astrophysics Data System (ADS)

    Zhang, R.; Jing, J.; Tao, J.; Hsu, S.-C.; Wang, G.; Cao, J.; Lee, C. S. L.; Zhu, L.; Chen, Z.; Zhao, Y.; Shen, Z.

    2013-07-01

    that comprehensively explores the chemical characterizations and source apportionments of PM2.5 aerosol speciation in Beijing by applying multiple approaches based on a completely seasonal perspective.

  18. On the autarchic use of solely PIXE data in particulate matter source apportionment studies by receptor modeling

    NASA Astrophysics Data System (ADS)

    Lucarelli, F.; Nava, S.; Calzolai, G.; Chiari, M.; Giannoni, M.; Traversi, R.; Udisti, R.

    2015-11-01

    Particle Induced X-ray Emission (PIXE) analysis of aerosol samples allows simultaneous detection of several elements, including important tracers of many particulate matter sources. This capability, together with the possibility of analyzing a high number of samples in very short times, makes PIXE a very effective tool for source apportionment studies by receptor modeling. However, important aerosol components, like nitrates, OC and EC, cannot be assessed by PIXE: this limitation may strongly compromise the results of a source apportionment study if based on PIXE data alone. In this work, an experimental dataset characterised by an extended chemical speciation (elements, EC-OC, ions) is used to test the effect of reducing input species in the application of one of the most widely used receptor model, namely Positive Matrix Factorization (PMF). The main effect of using only PIXE data is that the secondary nitrate source is not identified and the contribution of biomass burning is overestimated, probably due to the similar seasonal pattern of these two sources.

  19. Source apportionment modeling of volatile organic compounds in streams

    USGS Publications Warehouse

    Pankow, J.F.; Asher, W.E.; Zogorski, J.S.

    2006-01-01

    It often is of interest to understand the relative importance of the different sources contributing to the concentration cw of a contaminant in a stream; the portions related to sources 1, 2, 3, etc. are denoted cw,1, cw,2, cw,3, etc. Like c w, 'he fractions ??1, = cw,1/c w, ??2 = cw,2/cw, ??3 = cw,3/cw, etc. depend on location and time. Volatile organic compounds (VOCs) can undergo absorption from the atmosphere into stream water or loss from stream water to the atmosphere, causing complexities affecting the source apportionment (SA) of VOCs in streams. Two SA rules are elaborated. Rule 1: VOC entering a stream across the air/water interface exclusively is assigned to the atmospheric portion of cw. Rule 2: VOC loss by volatilization, flow loss to groundwater, in-stream degradation, etc. is distributed over cw,1 cw,2, c w,3, etc. in proportion to their corresponding ?? values. How the two SA rules are applied, as well as the nature of the SA output for a given case, will depend on whether transport across the air/water interface is handled using the net flux F convention or using the individual fluxes J convention. Four hypothetical stream cases involving acetone, methyl-tert-butyl ether (MTBE), benzene, chloroform, and perchloroethylene (PCE) are considered. Acetone and MTBE are sufficiently water soluble from air for a domestic atmospheric source to be capable of yielding cw values approaching the common water quality guideline range of 1 to 10 ??g/L. For most other VOCs, such levels cause net outgassing (F > 0). When F > 0 in a given section of stream, in the net flux convention, all of the ??j, for the compound remain unchanged over that section while cw decreases. A characteristic time ??d can be calculated to predict when there will be differences between SA results obtained by the net flux convention versus the individual fluxes convention. Source apportionment modeling provides the framework necessary for comparing different strategies for mitigating

  20. New source and process apportionment method using a three-dimensional chemical transport model: Process, Age, and Source region Chasing ALgorithm (PASCAL)

    NASA Astrophysics Data System (ADS)

    Matsui, H.; Koike, M.

    2012-08-01

    We have developed a new source and process apportionment method, the Process, Age, and Source region Chasing ALgorithm (PASCAL), and implemented it in a three-dimensional chemical transport model, the Community Multiscale Air Quality (CMAQ) model. By adding new variables (tagged species), PASCAL traces 1) the source region of emissions (source apportionment), 2) the age of individual species (elapsed time from emissions), 3) net and gross production and loss amounts from individual physical and chemical processes during transport (Lagrangian way), and 4) local production and loss rates at individual grid cells (Eulerian way) for primary and secondary aerosols and their precursor gases. The main advantage of PASCAL is the third one, which can trace accumulated production and loss amounts of individual processes during transport from source regions to each grid cell (Lagrangian type of integration) for both gross (production and loss) and net (gross production - loss) concentrations. Currently the method is applied for mixing ratios of CO and SO2 and mass concentrations of black carbon and sulfate aerosols. This algorithm is not impacted by the non-linearity of chemical reactions and is computationally efficient. CMAQ/PASCAL model calculations were conducted over the East Asian region to test its performance. The overall validity of PASCAL calculations is confirmed for all species, periods, altitudes, and regions. This algorithm will be a useful tool in evaluating source regions as well as formation and loss processes of aerosols in the atmosphere in order to make effective strategies for emissions reduction.

  1. Photochemical grid model implementation and application of VOC, NOx, and O3 source apportionment

    NASA Astrophysics Data System (ADS)

    Kwok, R. H. F.; Baker, K. R.; Napelenok, S. L.; Tonnesen, G. S.

    2015-01-01

    For the purposes of developing optimal emissions control strategies, efficient approaches are needed to identify the major sources or groups of sources that contribute to elevated ozone (O3) concentrations. Source-based apportionment techniques implemented in photochemical grid models track sources through the physical and chemical processes important to the formation and transport of air pollutants. Photochemical model source apportionment has been used to track source impacts of specific sources, groups of sources (sectors), sources in specific geographic areas, and stratospheric and lateral boundary inflow on O3. The implementation and application of a source apportionment technique for O3 and its precursors, nitrogen oxides (NOx) and volatile organic compounds (VOCs), for the Community Multiscale Air Quality (CMAQ) model are described here. The Integrated Source Apportionment Method (ISAM) O3 approach is a hybrid of source apportionment and source sensitivity in that O3 production is attributed to precursor sources based on O3 formation regime (e.g., for a NOx-sensitive regime, O3 is apportioned to participating NOx emissions). This implementation is illustrated by tracking multiple emissions source sectors and lateral boundary inflow. NOx, VOC, and O3 attribution to tracked sectors in the application are consistent with spatial and temporal patterns of precursor emissions. The O3 ISAM implementation is further evaluated through comparisons of apportioned ambient concentrations and deposition amounts with those derived from brute force zero-out scenarios, with correlation coefficients ranging between 0.58 and 0.99 depending on specific combination of target species and tracked precursor emissions. Low correlation coefficients occur for chemical regimes that have strong nonlinearity in O3 sensitivity, which demonstrates different functionalities between source apportionment and zero-out approaches, where appropriate use depends on whether source attribution or

  2. Metals and metalloids in atmospheric dust: Use of lead isotopic analysis for source apportionment

    NASA Astrophysics Data System (ADS)

    Felix Villar, Omar I.

    Mining activities generate aerosol in a wide range of sizes. Smelting activities produce mainly fine particles (<1 microm). On the other hand, milling, crushing and refining processes, as well tailings management, are significant sources of coarse particles (> 1 microm). The adverse effects of aerosols on human health depend mainly on two key characteristics: size and chemical composition. One of the main objectives of this research is to analyze the size distribution of contaminants in aerosol produced by mining operations. For this purpose, a Micro-Orifice Uniform Deposit Impactor (MOUDI) was utilized. Results from the MOUDI samples show higher concentrations of the toxic elements like lead and arsenic in the fine fraction (<1 microm). Fine particles are more likely to be deposited in the deeper zones of the respiratory system; therefore, they are more dangerous than coarse particles that can be filtered out in the upper respiratory system. Unfortunately, knowing the total concentration of contaminants does not give us enough information to identify the source of contamination. For this reason, lead isotopes have been introduced as fingerprints for source apportionment. Each source of lead has specific isotopic ratios; by knowing these ratios sources can be identified. During this research, lead isotopic ratios were analyzed at different sites and for different aerosol sizes. From these analyses it can be concluded that lead isotopes are a powerful tool to identify sources of lead. Mitigation strategies could be developed if the source of contamination is well defined. Environmental conditions as wind speed, wind direction, relative humidity and precipitation have an important role in the concentration of atmospheric dust. Dry environments with low relative humidity are ideal for the transport of aerosols. Results obtained from this research show the relationship between dust concentrations and meteorological parameters. Dust concentrations are highly correlated

  3. A Source Apportionment of U.S. Fine Particulate Matter Air Pollution

    PubMed Central

    Thurston, George D.; Ito, Kazuhiko; Lall, Ramona

    2011-01-01

    .5 components agreed well with the U.S. PM2.5 observed during the study period (mean=14.3 ug/m3; R2= 0.91). Apportionment regression analyses using single-element tracers for each source category gave results consistent with the APCA estimates. Comparisons of nearby sites indicated that the PM2.5 mass and the secondary aerosols were most homogenous spatially, while traffic PM2.5 and its tracer, EC, were among the most spatially representative of the source-related components. Comparison of apportionment results to a previous analysis of the 1979–1982 IP Network revealed similar and correlated major U.S. source category factors, albeit at lower levels than in the earlier period, suggesting a consistency in the U.S. spatial patterns of these source-related exposures over time, as well. These results indicate that applying source apportionment methods to the nationwide CSN can be an informative avenue for identifying and quantifying source components for the subsequent estimation of source-specific health effects, potentially contributing to more efficient regulation of PM2.5. PMID:24634604

  4. Photochemical grid model implementation of VOC, NOx, and O3 source apportionment

    NASA Astrophysics Data System (ADS)

    Kwok, R. H. F.; Baker, K. R.; Napelenok, S. L.; Tonnesen, G. S.

    2014-09-01

    For the purposes of developing optimal emissions control strategies, efficient approaches are needed to identify the major sources or groups of sources that contribute to elevated ozone (O3) concentrations. Source based apportionment techniques implemented in photochemical grid models track sources through the physical and chemical processes important to the formation and transport of air pollutants. Photochemical model source apportionment has been used to estimate impacts of specific sources, groups of sources (sectors), sources in specific geographic areas, and stratospheric and lateral boundary inflow on O3. The implementation and application of a source apportionment technique for O3 and its precursors, nitrogen oxides (NOx) and volatile organic compounds (VOC), for the Community Multiscale Air Quality (CMAQ) model are described here. The Integrated Source Apportionment Method (ISAM) O3 approach is a hybrid of source apportionment and source sensitivity in that O3 production is attributed to precursor sources based on O3 formation regime (e.g., for a NOx-sensitive regime, O3 is apportioned to participating NOx emissions). This implementation is illustrated by tracking multiple emissions source sectors and lateral boundary inflow. NOx, VOC, and O3 attribution to tracked sectors in the application are consistent with spatial and temporal patterns of precursor emissions. The O3 ISAM implementation is further evaluated through comparisons of apportioned ambient concentrations and deposition amounts with those derived from brute force zero-out scenarios, with correlation coefficients ranging between 0.58 and 0.99 depending on specific combination of target species and tracked precursor emissions. Low correlation coefficients occur for chemical regimes that have strong non-linearity in O3 sensitivity, which demonstrates different functionalities between source apportionment and zero-out approaches, depending on whether sources of interest are either to be accounted

  5. Source Apportionment Using Positive Matrix Factorization on Daily Measurements of Inorganic and Organic Speciated PM2.5

    PubMed Central

    Dutton, Steven J.; Vedal, Sverre; Piedrahita, Ricardo; Milford, Jana B.; Miller, Shelly L.; Hannigan, Michael P.

    2012-01-01

    Particulate matter less than 2.5 microns in diameter (PM2.5) has been linked with a wide range of adverse health effects. Determination of the sources of PM2.5 most responsible for these health effects could lead to improved understanding of the mechanisms of such effects and more targeted regulation. This has provided the impetus for the Denver Aerosol Sources and Health (DASH) study, a multi-year source apportionment and health effects study relying on detailed inorganic and organic PM2.5 speciation measurements. In this study, PM2.5 source apportionment is performed by coupling positive matrix factorization (PMF) with daily speciated PM2.5 measurements including inorganic ions, elemental carbon (EC) and organic carbon (OC), and organic molecular markers. A qualitative comparison is made between two models, PMF2 and ME2, commonly used for solving the PMF problem. Many previous studies have incorporated chemical mass balance (CMB) for organic molecular marker source apportionment on limited data sets, but the DASH data set is large enough to use multivariate factor analysis techniques such as PMF. Sensitivity of the PMF2 and ME2 models to the selection of speciated PM2.5 components and model input parameters was investigated in depth. A combination of diagnostics was used to select an optimum, 7-factor model using one complete year of daily data with pointwise measurement uncertainties. The factors included 1) a wintertime/methoxyphenol factor, 2) an EC/sterane factor, 3) a nitrate/polycyclic aromatic hydrocarbon (PAH) factor, 4) a summertime/selective aliphatic factor, 5) an n-alkane factor, 6) a middle oxygenated PAH/alkanoic acid factor and 7) an inorganic ion factor. These seven factors were qualitatively linked with known PM2.5 emission sources with varying degrees of confidence. Mass apportionment using the 7-factor model revealed the contribution of each factor to the mass of OC, EC, nitrate and sulfate. On an annual basis, the majority of OC and EC mass

  6. Sources of Size Segregated Sulfate Aerosols in the Arctic Summer

    NASA Astrophysics Data System (ADS)

    Ghahremaninezhadgharelar, R.; Norman, A. L.; Abbatt, J.; Levasseur, M.

    2015-12-01

    Aerosols drive significant radiative forcing and affect Arctic climate. Despite the importance of these particles in Arctic climate change, there are some key uncertainties in the estimation of their effects and sources. Aerosols in six size fractions between <0.49 to 7.0 microns in diameter were collected on board the Canadian Coast Guard Ship (CCGS) Amundsen in the Arctic, during July 2014. A cascade impactor fitted to a high volume sampler was used for this study and was modified to permit collection of SO2 after aerosols were removed from the gas stream. The isotopic composition of sulfate aerosols and SO2 was measured and apportionment calculations have been performed to quantify the contribution of biogenic as well as anthropogenic sources to the growth of different aerosol size fractions in the atmosphere. The presence of sea salt sulfate aerosols was especially high in coarse mode aerosols as expected. The contribution of biogenic sulfate concentration in this study was higher than anthropogenic sulfate. Around 70% of fine aerosols (<0.49 μm) and 86% of SO2 were from biogenic sources. Concentrations of biogenic sulfate for fine aerosols, ranging from 18 to 625 ng/m3, were five times higher than total biogenic sulfate concentrations measured during Fall in the same region (Rempillo et al., 2011). A comparison of the isotope ratio for SO2 and fine aerosols offers a way to determine aerosol growth from local SO2 oxidation. For some samples, the values for SO2 and fine aerosols were close together suggesting the same source for SO2 and aerosol sulfur.Aerosols drive significant radiative forcing and affect Arctic climate. Despite the importance of these particles in Arctic climate change, there are some key uncertainties in the estimation of their effects and sources. Aerosols in six size fractions between <0.49 to 7.0 microns in diameter were collected on board the Canadian Coast Guard Ship (CCGS) Amundsen in the Arctic, during July 2014. A cascade impactor

  7. Receptor modeling application framework for particle source apportionment.

    PubMed

    Watson, John G; Zhu, Tan; Chow, Judith C; Engelbrecht, Johann; Fujita, Eric M; Wilson, William E

    2002-12-01

    Receptor models infer contributions from particulate matter (PM) source types using multivariate measurements of particle chemical and physical properties. Receptor models complement source models that estimate concentrations from emissions inventories and transport meteorology. Enrichment factor, chemical mass balance, multiple linear regression, eigenvector. edge detection, neural network, aerosol evolution, and aerosol equilibrium models have all been used to solve particulate air quality problems, and more than 500 citations of their theory and application document these uses. While elements, ions, and carbons were often used to apportion TSP, PM10, and PM2.5 among many source types, many of these components have been reduced in source emissions such that more complex measurements of carbon fractions, specific organic compounds, single particle characteristics, and isotopic abundances now need to be measured in source and receptor samples. Compliance monitoring networks are not usually designed to obtain data for the observables, locations, and time periods that allow receptor models to be applied. Measurements from existing networks can be used to form conceptual models that allow the needed monitoring network to be optimized. The framework for using receptor models to solve air quality problems consists of: (1) formulating a conceptual model; (2) identifying potential sources; (3) characterizing source emissions; (4) obtaining and analyzing ambient PM samples for major components and source markers; (5) confirming source types with multivariate receptor models; (6) quantifying source contributions with the chemical mass balance; (7) estimating profile changes and the limiting precursor gases for secondary aerosols; and (8) reconciling receptor modeling results with source models, emissions inventories, and receptor data analyses. PMID:12492167

  8. Source apportionment of airborne particulate matter using inorganic and organic species as tracers

    NASA Astrophysics Data System (ADS)

    Wang, Yungang; Hopke, Philip K.; Xia, Xiaoyan; Rattigan, Oliver V.; Chalupa, David C.; Utell, Mark J.

    2012-08-01

    Source apportionment is typically performed on chemical composition data derived from particulate matter (PM) samples. However, many common sources no longer emit significant amounts of characteristic trace elements requiring the use of more comprehensive chemical characterization in order to fully resolve the PM sources. Positive matrix factorization (EPA PMF, version 4.1) was used to analyze 24-hr integrated molecular marker (MM), secondary inorganic ions, trace elements, carbonaceous species and light absorption data to investigate sources of PM2.5 in Rochester, New York between October 2009 and October 2010 to explore the role of specific MMs. An eight-factor solution was found for which the factors were identified as isoprene secondary organic aerosol (SOA), airborne soil, other SOA, diesel emissions, secondary sulfate, wood combustion, gasoline vehicle, and secondary nitrate contributing 6.9%, 12.8%, 3.7%, 7.8%, 45.5%, 9.1%, 7.9%, and 6.3% to the average PM2.5 concentration, respectively Concentrations of pentacosane, hexacosane, heptacosane, and octacosane in the gasoline vehicles factor were larger compared to diesel emissions. Aethalometer Delta-C was strongly associated with wood combustion. The compounds, n-heptacosanoic acid and n-octacosanoic acid, occasionally used in the past as tracers for road dust, were found to largely associate with SOA in this study. In comparison with a standard PMF analyses without MM, inclusion of them was necessary to resolve SOA and wood combustion factors in urban areas.

  9. Sensitivity of fluvial sediment source apportionment to mixing model assumptions: A Bayesian model comparison

    NASA Astrophysics Data System (ADS)

    Cooper, Richard J.; Krueger, Tobias; Hiscock, Kevin M.; Rawlins, Barry G.

    2014-11-01

    Mixing models have become increasingly common tools for apportioning fluvial sediment load to various sediment sources across catchments using a wide variety of Bayesian and frequentist modeling approaches. In this study, we demonstrate how different model setups can impact upon resulting source apportionment estimates in a Bayesian framework via a one-factor-at-a-time (OFAT) sensitivity analysis. We formulate 13 versions of a mixing model, each with different error assumptions and model structural choices, and apply them to sediment geochemistry data from the River Blackwater, Norfolk, UK, to apportion suspended particulate matter (SPM) contributions from three sources (arable topsoils, road verges, and subsurface material) under base flow conditions between August 2012 and August 2013. Whilst all 13 models estimate subsurface sources to be the largest contributor of SPM (median ˜76%), comparison of apportionment estimates reveal varying degrees of sensitivity to changing priors, inclusion of covariance terms, incorporation of time-variant distributions, and methods of proportion characterization. We also demonstrate differences in apportionment results between a full and an empirical Bayesian setup, and between a Bayesian and a frequentist optimization approach. This OFAT sensitivity analysis reveals that mixing model structural choices and error assumptions can significantly impact upon sediment source apportionment results, with estimated median contributions in this study varying by up to 21% between model versions. Users of mixing models are therefore strongly advised to carefully consider and justify their choice of model structure prior to conducting sediment source apportionment investigations.

  10. Source apportionment of airborne particulate matter for the speciation trends network site in Cleveland, OH

    SciTech Connect

    Liming Zhou; Philip K. Hopke; Weixiang Zhao

    2009-03-15

    Aerosol composition data from the Speciation Trends Network (STN) site (East 14th Street) in Cleveland, OH, were analyzed by advanced receptor model methods for source apportionment as well as by the standard positive matrix factorization (PMF) using PMF2. These different models are used in combination to test model limitations. These data were 24-hr average mass concentrations and compositions obtained for samples taken every third day from 2001 to 2003. The Multilinear Engine (ME) was used to solve an expanded model to estimate the source profiles and source contributions and also to investigate the wind speed, wind direction, time-of-day, weekend/weekday, and seasonal effects. PMF2 was applied to the same dataset. Potential source contribution function (PSCF) and conditional probability function (CPF) analyses were used to locate the regional and local sources using the resolved source contributions and appropriate meteorological data. Very little difference was observed between the results of the expanded model and the PMF2 values for the profiles and source contribution time series. The identified sources were as ferrous smelter, secondary sulfate, secondary nitrate, soil/combustion mixture, steel mill, traffic, wood smoke, and coal burning. The CPF analysis was useful in helping to identify local sources, whereas the PSCF results were only useful for regional source areas. Both of these analyses were more useful than the wind directional factor derived from the expanded factor analysis. However, the expanded analysis provided direct information on seasonality and day-of-week behavior of the sources. 28 refs., 8 figs., 4 tabs.

  11. Source apportionment studies at different european sites with time and size resolved trace element data

    NASA Astrophysics Data System (ADS)

    Richard, Agnes; Furger, Markus; Bukowiecki, Nicolas; Lienemann, Peter; Flechsig, Uwe; Rickers-Appel, Karen; Minguillon, Mari-Cruz; Reche, Cristina; Prevot, Andre; Baltensperger, Urs

    2010-05-01

    Although trace elements do not contribute substantially to the total mass of air pollutants they can attribute significantly to source identifications. Apportionment studies performed with positive matrix factorization (PMF) took advantage of the gain in information obtained through a high time resolution (i.e. in the order of hours). Furthermore, aerosols sampled with the rotating drum impactor (RDI) are segregated into three size ranges (PM10-2.5, PM2.5-1 and PM0.1-1). This involves the possibility to identify different sources for a single element depending on its emitted particle size. An example is iron, which is attributed to mineral dust in the coarse mode and to mechanical abrasion in the fine mode. A broad range of elements (Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Se, Sr, Zr, Cd, Sn, Sb, Ba) was analyzed with synchrotron-radiation based x-ray fluorescence. Field measurements were carried out during 2008 and 2009 at different places in Europe in the context of EUCAARI (Zürich, CH), EMEP (Payerne, CH) and DAURE (Barcelona, ES) campaigns. Comparison of source profiles from different campaigns shows regional variability due to individual properties of rural and urban sites. As would be expected, urban areas exhibit stronger traffic factors, whereas mineral dust is enhanced at rural sites. Also geographical differences can be distinguished by PMF, as the Barcelona site clearly showed a marine factor and industrial influences, which are absent in Switzerland.

  12. Characterization of regional carbonaceous particulate matter in Central Texas using combined radiocarbon and organic tracer source apportionment

    NASA Astrophysics Data System (ADS)

    Sheesley, R. J.; Barrett, T.; Nallathamby, P. D.

    2012-12-01

    Atmospheric particulate matter (PM) in Texas can be transported readily among urban, rural and natural areas. Depending upon the season and transport conditions, major Texas cities can readily impact PM loadings in urban and rural areas across the state. To begin to assess the potential impacts of anthropogenic and biogenic sources on carbonaceous aerosol loading in Central Texas, source apportionment modeling is needed. For this study, two rigorous models have been combined to provide better constraints on potential emission sources; organic tracer chemical mass balance modeling and radiocarbon source apportionment have been combined to provide complementary information on primary emission contributions (motor vehicle exhaust and biomass burning) and total fossil vs modern (biogenic plus biomass burning) contributions to carbonaceous PM. Preliminary results indicate more than 50% of carbonaceous PM is from biogenic/biomass burning emissions during the summer study period. Organic tracer CMB will be added to increase specificity in the fossil and modern carbon emission sources (ie. motor vehicle exhaust and biomass burning). This detailed, top-down study can provide crucial constraints for future regional, bottom-up approaches which focus on emissions inventories.

  13. Source apportionment of fine particles in Tennessee using a source-oriented model.

    PubMed

    Doraiswamy, Prakash; Davis, Wayne T; Miller, Terry L; Fu, Joshua S

    2007-04-01

    Source apportionment of fine particles (PM2.5, particulate matter < 2 microm in aerodynamic diameter) is important to identify the source categories that are responsible for the concentrations observed at a particular receptor. Although receptor models have been used to do source apportionment, they do not fully take into account the chemical reactions (including photochemical reactions) involved in the formation of secondary fine particles. Secondary fine particles are formed from photochemical and other reactions involving precursor gases, such as sulfur dioxide, oxides of nitrogen, ammonia, and volatile organic compounds. This paper presents the results of modeling work aimed at developing a source apportionment of primary and secondary PM2.5. On-road mobile source and point source inventories for the state of Tennessee were estimated and compiled. The national emissions inventory for the year 1999 was used for the other states. U.S. Environmental Protection Agency Models3/Community Multi-Scale Air Quality modeling system was used for the photochemical/secondary particulate matter modeling. The modeling domain consisted of a nested 36-12-4-km domain. The 4-km domain covered the entire state of Tennessee. The episode chosen for the modeling runs was August 29 to September 9, 1999. This paper presents the approach used and the results from the modeling and attempts to quantify the contribution of major source categories, such as the on-road mobile sources (including the fugitive dust component) and coal-fired power plants, to observed PM2.5 concentrations in Tennessee. The results of this work will be helpful in policy issues targeted at designing control strategies to meet the PM2.5 National Ambient Air Quality Standards in Tennessee. PMID:17458460

  14. Source apportionment of size-segregated atmospheric particles based on the major water-soluble components in Lecce (Italy).

    PubMed

    Contini, D; Cesari, D; Genga, A; Siciliano, M; Ielpo, P; Guascito, M R; Conte, M

    2014-02-15

    Atmospheric aerosols have potential effects on human health, on the radiation balance, on climate, and on visibility. The understanding of these effects requires detailed knowledge of aerosol composition and size distributions and of how the different sources contribute to particles of different sizes. In this work, aerosol samples were collected using a 10-stage Micro-Orifice Uniform Deposit Impactor (MOUDI). Measurements were taken between February and October 2011 in an urban background site near Lecce (Apulia region, southeast of Italy). Samples were analysed to evaluate the concentrations of water-soluble ions (SO4(2-), NO3(-), NH4(+), Cl(-), Na(+), K(+), Mg(2+) and Ca(2+)) and of water-soluble organic and inorganic carbon. The aerosols were characterised by two modes, an accumulation mode having a mass median diameter (MMD) of 0.35 ± 0.02 μm, representing 51 ± 4% of the aerosols and a coarse mode (MMD=4.5 ± 0.4 μm), representing 49 ± 4% of the aerosols. The data were used to estimate the losses in the impactor by comparison with a low-volume sampler. The average loss in the MOUDI-collected aerosol was 19 ± 2%, and the largest loss was observed for NO3(-) (35 ± 10%). Significant losses were observed for Ca(2+) (16 ± 5%), SO4(2-) (19 ± 5%) and K(+) (10 ± 4%), whereas the losses for Na(+) and Mg(2+) were negligible. Size-segregated source apportionment was performed using Positive Matrix Factorization (PMF), which was applied separately to the coarse (size interval 1-18 μm) and accumulation (size interval 0.056-1 μm) modes. The PMF model was able to reasonably reconstruct the concentration in each size-range. The uncertainties in the source apportionment due to impactor losses were evaluated. In the accumulation mode, it was not possible to distinguish the traffic contribution from other combustion sources. In the coarse mode, it was not possible to efficiently separate nitrate from the contribution of crustal/resuspension origin. PMID:24295746

  15. Sensitivity of fluvial sediment source apportionment to mixing model assumptions: A Bayesian model comparison

    PubMed Central

    Cooper, Richard J; Krueger, Tobias; Hiscock, Kevin M; Rawlins, Barry G

    2014-01-01

    Mixing models have become increasingly common tools for apportioning fluvial sediment load to various sediment sources across catchments using a wide variety of Bayesian and frequentist modeling approaches. In this study, we demonstrate how different model setups can impact upon resulting source apportionment estimates in a Bayesian framework via a one-factor-at-a-time (OFAT) sensitivity analysis. We formulate 13 versions of a mixing model, each with different error assumptions and model structural choices, and apply them to sediment geochemistry data from the River Blackwater, Norfolk, UK, to apportion suspended particulate matter (SPM) contributions from three sources (arable topsoils, road verges, and subsurface material) under base flow conditions between August 2012 and August 2013. Whilst all 13 models estimate subsurface sources to be the largest contributor of SPM (median ∼76%), comparison of apportionment estimates reveal varying degrees of sensitivity to changing priors, inclusion of covariance terms, incorporation of time-variant distributions, and methods of proportion characterization. We also demonstrate differences in apportionment results between a full and an empirical Bayesian setup, and between a Bayesian and a frequentist optimization approach. This OFAT sensitivity analysis reveals that mixing model structural choices and error assumptions can significantly impact upon sediment source apportionment results, with estimated median contributions in this study varying by up to 21% between model versions. Users of mixing models are therefore strongly advised to carefully consider and justify their choice of model structure prior to conducting sediment source apportionment investigations. Key Points An OFAT sensitivity analysis of sediment fingerprinting mixing models is conducted Bayesian models display high sensitivity to error assumptions and structural choices Source apportionment results differ between Bayesian and frequentist approaches PMID

  16. A new methodology to assess the performance and uncertainty of source apportionment models in intercomparison exercises

    NASA Astrophysics Data System (ADS)

    Belis, C. A.; Pernigotti, D.; Karagulian, F.; Pirovano, G.; Larsen, B. R.; Gerboles, M.; Hopke, P. K.

    2015-10-01

    A new methodology to assess source apportionment model performance in intercomparison exercises, encompassing the preparation of real-world and synthetic datasets and the evaluation of the source apportionment results reported by participants, is described. The evaluation consists of three types of tests: complementary tests, preliminary tests, and performance tests. The complementary tests provide summary information about the source apportionment results as a whole. The preliminary tests check whether source/factors belong to a given source category. Three types of indicators: Pearson correlation (Pearson), standardized identity distance (SID), and weighted difference (WD) are used to test factor/source chemical profiles, while factor/source time series and contribution-to-species values are tested only using the Pearson. The performance tests, based on international standards for proficiency testing, are targeted at evaluating whether the reported biases in the quantification of the factor/source contribution estimates (SCEs) and uncertainties are consistent with previously established quality standards in a fitness-for-purpose approach. Moreover, the consistency of the SCE time series is evaluated using a variant of the RMSE normalised by the reference standard uncertainty. The described methodology facilitates a thorough evaluation of the source apportionment output. The new indicator to compare source or factor profiles presented in this study (SID) is more robust and provides additional information compared to the existing ones.

  17. DEVELOPMENT AND EVALUATION OF PM 2.5 SOURCE APPORTIONMENT METHODOLOGIES

    EPA Science Inventory

    The receptor model called Positive Matrix Factorization (PMF) has been extensively used to apportion sources of ambient fine particulate matter (PM2.5), but the accuracy of source apportionment results currently remains unknown. In addition, air quality forecast model...

  18. MONITORING AND SOURCE APPORTIONMENT OF PARTICULATE MATTER NEAR A LARGE PHOSPHORUS PRODUCTION FACILITY

    EPA Science Inventory

    A source apportionment study was conducted to identify sources within a large elemental phosphorus plant that contribute to exceedances of the National Ambient Air Quality Standard for 24-h PM10. Ambient data were collected at three monitoring sites from October 1996 through Ju...

  19. Chemical Characterization and Source Apportionment of Particulate Matter in Lahore, Pakistan

    NASA Astrophysics Data System (ADS)

    von Schneidemesser, Erika; Stone, Elizabeth; Quraishi, Tauseef; Schauer, James; Shafer, Martin; Mahmood, Abid

    2010-05-01

    Lahore, Pakistan is a rapidly growing megacity with a population approaching 10 million. A significant issue affecting many of the world's megacities is extremely high levels of air pollution associated with transportation, solid fuel combustion, and industrial sources. High ambient concentrations of particulate matter (PM), as well as high levels of toxic components of PM, have been linked to increased mortality and morbidity. Although much focus has been directed at particulate matter mass, in many developing and underdeveloped nations, the adverse health impacts of high levels of PM are further enhanced by the high concentrations of toxic components in PM. To address these issues is Lahore, a measurement campaign of fine (PM2.5) and coarse (PM10-2.5) particulate matter was conducted for the 2007 calendar year, which included measurements of particle mass, detailed chemical composition of PM and source apportionment calculations. Annual average PM2.5 and PM10 concentrations were measured to be 194 µg m-3 and 336 µg m-3, respectively, with daily 24-hour maximum concentrations of 410 µg m-3 and 650 µg m-3 for PM2.5 and PM10, respectively. PM2.5 and PM10 samples were analysed for organic and elemental carbon, organic species, ionic species, elemental composition, water soluble elements and biological activity using a macrophage ROS assay. The coarse mode was dominated by crustal dust components, while the fine fraction was dominated by carbonaceous aerosols. The PM10 elemental composition data, which included data for toxic metals, was processed using principle component analysis to determine likely source categories. Seven factors were identified explaining 91% of the variance of the measured components. The factors included a number of industrial sources, re-suspended soil, mobile sources, and regional secondary aerosol. Source contributions to the organic carbon (OC) component of the PM2.5 fraction were identified using organic tracer species and chemical

  20. Fine particulate matter in the tropical environment: monsoonal effects, source apportionment, and health risk assessment

    NASA Astrophysics Data System (ADS)

    Khan, M. F.; Latif, M. T.; Saw, W. H.; Amil, N.; Nadzir, M. S. M.; Sahani, M.; Tahir, N. M.; Chung, J. X.

    2016-01-01

    The health implications of PM2.5 in the tropical region of Southeast Asia (SEA) are significant as PM2.5 can pose serious health concerns. PM2.5 concentration and sources here are strongly influenced by changes in the monsoon regime from the south-west quadrant to the north-east quadrant in the region. In this work, PM2.5 samples were collected at a semi-urban area using a high-volume air sampler at different seasons on 24 h basis. Analysis of trace elements and water-soluble ions was performed using inductively coupled plasma mass spectroscopy (ICP-MS) and ion chromatography (IC), respectively. Apportionment analysis of PM2.5 was carried out using the United States Environmental Protection Agency (US EPA) positive matrix factorization (PMF) 5.0 and a mass closure model. We quantitatively characterized the health risks posed to human populations through the inhalation of selected heavy metals in PM2.5. 48 % of the samples collected exceeded the World Health Organization (WHO) 24 h PM2.5 guideline but only 19 % of the samples exceeded 24 h US EPA National Ambient Air Quality Standard (NAAQS). The PM2.5 concentration was slightly higher during the north-east monsoon compared to south-west monsoon. The main trace metals identified were As, Pb, Cd, Ni, Mn, V, and Cr while the main ions were SO42-, NO3-, NH4+, and Na. The mass closure model identified four major sources of PM2.5 that account for 55 % of total mass balance. The four sources are mineral matter (MIN) (35 %), secondary inorganic aerosol (SIA) (11 %), sea salt (SS) (7 %), and trace elements (TE) (2 %). PMF 5.0 elucidated five potential sources: motor vehicle emissions coupled with biomass burning (31 %) were the most dominant, followed by marine/sulfate aerosol (20 %), coal burning (19 %), nitrate aerosol (17 %), and mineral/road dust (13 %). The hazard quotient (HQ) for four selected metals (Pb, As, Cd, and Ni) in PM2.5 mass was highest in PM2.5 mass from the coal burning source and least in PM2.5 mass

  1. Source apportionment of particles at Station Nord, North East Greenland during 2008-2010 using COPREM and PMF analysis

    NASA Astrophysics Data System (ADS)

    Nguyen, Q. T.; Skov, H.; Sørensen, L. L.; Jensen, B. J.; Grube, A. G.; Massling, A.; Glasius, M.; Nøjgaard, J. K.

    2012-09-01

    In order to develop strategies for controlling and reducing Arctic air pollution, there is a need to understand the basic mechanisms for determining the fate of air pollution in the Arctic. Sources of atmospheric particles at Station Nord (81°36' N, 16°40' W) in North East Greenland were evaluated for a two-year period from March 2008 to February 2010. Source apportionment using Positive Matrix Factorization (PMF) and COnstrained Physical Receptor Model (COPREM) was based on measurements of black carbon, elements (Al, Si, S, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, As, Se, Br, Rb, Sr, Zr, Pb) and inorganic ions (SO2, SO42-, Na+, NH4+, NO3-, Cl-). In general, source apportionment results by PMF and COPREM showed good agreement. Five sources adequately explained the measurements, which included a Marine and a Soil source of natural origin and three additional anthropogenic sources, which were all influenced by metal industries. One anthropogenic source was dominated by Zn of which air mass back trajectories using the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model suggested a Canadian Arctic origin, despite certain influences from southern and eastern origins. Another anthropogenic source was characterised by high concentrations of Pb and As, which has been historically referred to as a Combustion source at Station Nord. The impacts of large-scale industry in Siberia, Russia were evident through high Cu concentrations in both the Combustion source and an additional Cu/Ni source. Br correlated well with the anthropogenic species S and Pb though the elements are unlikely to have a common origin. More likely, sulphuric acid aerosols serve as transport containers for Br species of marine or local origin. Of particular relevance to climate, sources of black carbon were identified to be mainly anthropogenic and most probably of Siberian origin (80-98%).

  2. Source apportionment of particles at Station Nord, North East Greenland during 2008-2010 using COPREM and PMF analysis

    NASA Astrophysics Data System (ADS)

    Nguyen, Q. T.; Skov, H.; Sørensen, L. L.; Jensen, B. J.; Grube, A. G.; Massling, A.; Glasius, M.; Nøjgaard, J. K.

    2013-01-01

    In order to develop strategies for controlling and reducing Arctic air pollution, there is a need to understand the basic mechanisms for determining the fate of air pollution in the Arctic. Sources of atmospheric particles at Station Nord (81° 36' N, 16° 40' W) in North East Greenland were evaluated for a two-year period from March 2008 to February 2010. Source apportionment using Positive Matrix Factorization (PMF) and COnstrained Physical REceptor Model (COPREM) was based on measurements of black carbon, elements (Al, Si, S, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, As, Se, Br, Rb, Sr, Zr, Pb) and inorganic ions (SO2, SO42-, Na+, NH4+, NO3-, Cl2-. In general, source apportionment results by PMF and COPREM showed good agreement. Five sources adequately explained the measurements, which included a Marine and a Soil source of natural origin and three additional anthropogenic sources, which were all influenced by metal industries. One anthropogenic source was dominated by Zn of which air mass back trajectories using the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model suggested a Canadian Arctic origin, despite certain influences from Southern and Eastern origins. Another anthropogenic source was characterised by high concentrations of Pb and As, which has been historically referred to as a Combustion source at Station Nord. The impacts of large-scale industry in Siberia, Russia were evident through high Cu concentrations in both the Combustion source and an additional Cu/Ni source. Br correlated well with the anthropogenic species S and Pb though the elements are unlikely to have a common origin. More likely, sulphuric acid aerosols serve as transport containers for Br species of marine origin. Of particular relevance to climate, sources of black carbon were identified to be mainly anthropogenic and most probably of Siberian origin (80-98%).

  3. Chemical speciation and source apportionment of fine particulate matter in Santiago, Chile, 2013.

    PubMed

    Villalobos, Ana M; Barraza, Francisco; Jorquera, Héctor; Schauer, James J

    2015-04-15

    Santiago is one of the largest cities in South America and has experienced high fine particulate matter (PM2.5) concentrations in fall and winter months for decades. To better understand the sources of fall and wintertime pollution in Santiago, PM2.5 samples were collected for 24 h every weekday from March to October 2013 for chemical analysis. Samples were analyzed for mass, elemental carbon (EC), organic carbon (OC), water soluble organic carbon (WSOC), water soluble nitrogen (WSTN), secondary inorganic ions, and particle-phase organic tracers for source apportionment. Selected samples were analyzed as monthly composites for organic tracers. PM2.5 concentrations were considerably higher in the coldest months (June-July), averaging (mean ± standard deviation) 62±15 μg/m(3) in these two months. Average fine particle mass concentration during the study period was 40±20 μg/m(3). Organic matter during the peak winter months was the major component of fine particles comprising around 70% of the particle mass. Source contributions to OC were calculated using organic molecular markers and a chemical mass balance (CMB) receptor model. The four combustion sources identified were wood smoke, diesel engine emission, gasoline vehicles, and natural gas. Wood smoke was the predominant source of OC, accounting for 58±42% of OC in fall and winter. Wood smoke and nitrate were the major contributors to PM2.5. In fall and winter, wood smoke accounted for 9.8±7.1 μg/m(3) (21±15%) and nitrate accounted for 9.1±4.8 μg/m(3) (20±10%) of fine PM. The sum of secondary inorganic ions (sulfate, nitrate, and ammonium) represented about 30% of PM2.5 mass. Secondary organic aerosols contributed only in warm months, accounting for about 30% of fine PM during this time. PMID:25617780

  4. Problems in the fingerprints based polycyclic aromatic hydrocarbons source apportionment analysis and a practical solution.

    PubMed

    Zou, Yonghong; Wang, Lixia; Christensen, Erik R

    2015-10-01

    This work intended to explain the challenges of the fingerprints based source apportionment method for polycyclic aromatic hydrocarbons (PAH) in the aquatic environment, and to illustrate a practical and robust solution. The PAH data detected in the sediment cores from the Illinois River provide the basis of this study. Principal component analysis (PCA) separates PAH compounds into two groups reflecting their possible airborne transport patterns; but it is not able to suggest specific sources. Not all positive matrix factorization (PMF) determined sources are distinguishable due to the variability of source fingerprints. However, they constitute useful suggestions for inputs for a Bayesian chemical mass balance (CMB) analysis. The Bayesian CMB analysis takes into account the measurement errors as well as the variations of source fingerprints, and provides a credible source apportionment. Major PAH sources for Illinois River sediments are traffic (35%), coke oven (24%), coal combustion (18%), and wood combustion (14%). PMID:26208321

  5. Source Apportionment of Primary and Secondary Fine Particulate Matter in China

    NASA Astrophysics Data System (ADS)

    Hu, J.; Zhang, H.; Ying, Q.

    2015-12-01

    In the past few decades, China have been facing extreme particulate matter (PM) pollution problems due to the combination of fast increase of population, industrialization, urbanization and associated energy consumption and lagging of sufficient emission control measures. Studies have identified the major components of fine PM (PM2.5) in China include primary PM (which is directly emitted into the atmosphere), sulfate and nitrate (which are mainly secondary PM, i.e., formed from gaseous precursors), and organic aerosols (which can be primary or secondary). Contributions of different source sectors to the different PM components are substantially different; therefore source apportionment of these components can provide critical information needed for policy makers to design effective emission control strategies. In the current study, a source-oriented version of the Community Multiscale Air Quality (CMAQ) model that directly tracks the contributions from multiple emission sources to primary and secondary PM2.5 is developed, and then applied to determine the regional contributions of power, industry, transportation and residential sectors to primary PM, nitrate and sulfate concentrations in China. Four months in 2012-2013 are simulated to predict the seasonal variations of source contributions. Model predictions are evaluated with ambient measured concentrations. The source-oriented CMAQ model is capable of reproducing most of the available PM10 and PM2.5 mass, and PM2.5 EC, POC, nitrate and sulfate observations. Predicted source contributions for EC also generally agree with to the source contributions estimated by receptor models reported in previous studies. Model predictions suggest residential is a major contributor to primary PM (30-70%) in the spring and winter, and industrial contributes 40-60% of primary PM in the summer and fall; Transportation is an important source for EC (20-30%); Power sector is the dominating source of nitrate and sulfate in both

  6. Weak acid extractable metals in Bramble Bay, Queensland, Australia: temporal behaviour, enrichment and source apportionment.

    PubMed

    Brady, James P; Ayoko, Godwin A; Martens, Wayde N; Goonetilleke, Ashantha

    2015-02-15

    Sediment samples were taken from six sampling sites in Bramble Bay, Queensland, Australia between February and November in 2012. They were analysed for a range of heavy metals including Al, Fe, Mn, Ti, Ce, Th, U, V, Cr, Co, Ni, Cu, Zn, As, Cd, Sb, Te, Hg, Tl and Pb. Fraction analysis, Enrichment Factors and Principal Component Analysis-Absolute Principal Component Scores (PCA-APCS) were carried out in order to assess metal pollution, potential bioavailability and source apportionment. Cr and Ni exceeded the Australian Interim Sediment Quality Guidelines at some sampling sites, while Hg was found to be the most enriched metal. Fraction analysis identified increased weak acid soluble Hg and Cd during the sampling period. Source apportionment via PCA-APCS found four sources of metals pollution, namely, marine sediments, shipping, antifouling coatings and a mixed source. These sources need to be considered in any metal pollution control measure within Bramble Bay. PMID:25537749

  7. Concentrations and source apportionment of PM10 and associated major and trace elements in the Rhodes Island, Greece.

    PubMed

    Argyropoulos, Georgios; Manoli, Evangelia; Kouras, Athanasios; Samara, Constantini

    2012-08-15

    Ambient concentrations of PM(10) and associated major and trace elements were measured over the cold and the warm season of 2007 at two sites located in the Rhodes Island (Greece), in Eastern Mediterranean, aimed at source apportionment by Chemical Mass Balance (CMB) receptor modeling. Source chemical profiles, necessary in CMB modeling, were obtained for a variety of emission sources that could possibly affect the study area, including sea spray, geological material, soot emissions from the nearby oil-fuelled thermal power plant, and other anthropogenic activities, such as vehicular traffic, residential oil combustion, wood burning, and uncontrolled open-air burning of agricultural biomass and municipal waste. Source apportionment of PM(10) and elemental components was carried out by employing an advanced CMB version, the Robotic Chemical Mass Balance model (RCMB). Vehicular emissions were found to be major PM(10) contributor accounting, on average, for 36.8% and 31.7% during the cold period, and for 40.9% and 39.2% in the warm period at the two sites, respectively. The second largest source of ambient PM(10), with minor seasonal variation, was secondary sulfates (mainly ammonium and calcium sulfates), with total average contribution around 16.5% and 18% at the two sites. Soil dust was also a remarkable source contributing around 22% in the warm period, whereas only around 10% in the cold season. Soot emitted from the thermal power plant was found to be negligible contributor to ambient PM(10) (<1%), however it appeared to appreciably contribute to the ambient V and Ni (11.3% and 5.1%, respectively) at one of the sites during the warm period, when electricity production is intensified. Trajectory analysis did not indicate any transport of Sahara dust; on the contrary, long range transport of soil dust from arid continental regions of Minor Asia and of biomass burning aerosol from the countries surrounding the Black Sea was considered possible. PMID:22705902

  8. Workgroup Report: Workshop on Source Apportionment of Particulate Matter Health Effects—Intercomparison of Results and Implications

    PubMed Central

    Thurston, George D.; Ito, Kazuhiko; Mar, Therese; Christensen, William F.; Eatough, Delbert J.; Henry, Ronald C.; Kim, Eugene; Laden, Francine; Lall, Ramona; Larson, Timothy V.; Liu, Hao; Neas, Lucas; Pinto, Joseph; Stölzel, Matthias; Suh, Helen; Hopke, Philip K.

    2005-01-01

    Although the association between exposure to ambient fine particulate matter with aerodynamic diameter < 2.5 μm (PM2.5) and human mortality is well established, the most responsible particle types/sources are not yet certain. In May 2003, the U.S. Environmental Protection Agency’s Particulate Matter Centers Program sponsored the Workshop on the Source Apportionment of PM Health Effects. The goal was to evaluate the consistency of the various source apportionment methods in assessing source contributions to daily PM2.5 mass–mortality associations. Seven research institutions, using varying methods, participated in the estimation of source apportionments of PM2.5 mass samples collected in Washington, DC, and Phoenix, Arizona, USA. Apportionments were evaluated for their respective associations with mortality using Poisson regressions, allowing a comparative assessment of the extent to which variations in the apportionments contributed to variability in the source-specific mortality results. The various research groups generally identified the same major source types, each with similar elemental makeups. Intergroup correlation analyses indicated that soil-, sulfate-, residual oil-, and salt-associated mass were most unambiguously identified by various methods, whereas vegetative burning and traffic were less consistent. Aggregate source-specific mortality relative risk (RR) estimate confidence intervals overlapped each other, but the sulfate-related PM2.5 component was most consistently significant across analyses in these cities. Analyses indicated that source types were a significant predictor of RR, whereas apportionment group differences were not. Variations in the source apportionments added only some 15% to the mortality regression uncertainties. These results provide supportive evidence that existing PM2.5 source apportionment methods can be used to derive reliable insights into the source components that contribute to PM2.5 health effects. PMID:16330361

  9. Source apportionment of black carbon in PM2.5 in China and its implications on estimation of direct radiative forcing

    NASA Astrophysics Data System (ADS)

    Du, K.; Deng, J.; Chen, B.; Gustafsson, O.; Andersson, A.-; Lee, M.; Kirillova, E. N.; Kruså, M.

    2012-12-01

    Chinese black carbon (BC) causes concerns for climate warming and air pollution, yet the emission sources of black carbon are in large uncertainty. Emission inventory models suggest that fossil fuel and biomass/biofuel burning are the primary contributors to atmospheric BC. In this study, top-down sourcing of Chinese BC was conducted to quantify the apportionment between bio- and fossil- based fuel burning using radiocarbon method. Results for black carbon aerosols collected at urban and regional receptor areas showed that 81±5% of Chinese BC were produced from fossil fuel combustion, contrasting with the results from emission inventories, which report 50-70% of BC were from fossil fuel combustion. Since fossil BC aerosols are perceived as stronger climate forcers than biomass BC aerosols, accurate understanding of BC apportionment would be essential to improve modeling of climate effect of BC. A simulation on BC's radiative forcing effect was carried out by differentiating the sources using the top-down approach. Preliminary modeling results are presented.

  10. IMPROVING PARTICULATE MATTER SOURCE APPORTIONMENT FOR HEALTH STUDIES: A TRAINED RECEPTOR MODELING APPROACH WITH SENSITIVITY, UNCERTAINTY AND SPATIAL ANALYSES

    EPA Science Inventory

    An approach for conducting PM source apportionment will be developed, tested, and applied that directly addresses limitations in current SA methods, in particular variability, biases, and intensive resource requirements. Uncertainties in SA results and sensitivities to SA inpu...

  11. Single source impacts estimated with photochemical model source sensitivity and apportionment approaches

    NASA Astrophysics Data System (ADS)

    Baker, Kirk R.; Kelly, James T.

    2014-10-01

    Some sources may need to estimate ozone and secondarily formed PM2.5 as part of the permit application process under the Clean Air Act New Source Review program. Photochemical grid models represent state-of-the-science gas- and particle-phase chemistry and provide a realistic chemical and physical environment for assessing changes in air quality resulting from changes in emissions. When using these tools for single source impact assessments, it is important to differentiate a single source impact from other emissions sources and to understand how well contemporary grid model applications capture near-source transport and chemistry. Here for the first time, both source apportionment and source sensitivity approaches (brute-force changes and high-order direct decoupled method) are used in a photochemical grid model to isolate impacts of a specific facility. These single source impacts are compared with in-plume measurements made as part of a well-characterized 1999 TVA Cumberland aircraft plume transect field study. The techniques were able to isolate the impacts of the TVA plume in a manner consistent with observations. The model predicted in-plume concentrations well when the observations were averaged to the grid scale, although peak concentrations of primary pollutants were generally underestimated near the source, possibly due to dilution in the 4-km grid cell.

  12. The qualitative and quantitative source apportionments of polycyclic aromatic hydrocarbons in size dependent road deposited sediment.

    PubMed

    Zhang, Jin; Wang, Jing; Hua, Pei; Krebs, Peter

    2015-02-01

    This study showcases the qualitative and quantitative source apportionments of size-dependent polycyclic aromatic hydrocarbons (PAHs) in road deposited sediment by means of molecular diagnostic ratio (MDR) and positive matrix factorisation (PMF) approaches. The MDR was initially used to narrow the PAH source candidates. PMF modelling was subsequently used to provide more precise source apportionment with the assistance of a multiple linear regression analysis. Through a combined qualitative and quantitative source apportionment, different potential source contributors were identified at different size fractions. Explicitly, three major contributors to sorption at the size fraction of 1000-400 μm were tentatively identified as incineration (26%), coal combustion (53%) and gasoline-powered vehicle (20%). Four major contributors to the size fraction of 400-100 μm were identified as gasoline-powered vehicle (25%), surface pavement (15%), diesel-powered vehicle (37%) and industrial boiler (24%). Four major contributors to the size fraction of 100-63 μm were identified as cogeneration emission (13%), diesel-powered vehicle (28%), tire debris (45%) and wood combustion (14%). The potential contributors in the size fraction 63-0.45 μm were identified as diesel-powered vehicle (21%), heterogeneous sources (41%) and biomass burning (38%). In addition, the highest ∑16PAH concentration was found in the smallest size fraction of 63-0.45 μm, which is also where the highest BaPE and TEF values for potential risk assessment occurred. PMID:25310884

  13. Do anthropogenic, continental or coastal aerosol sources impact on a marine aerosol signature at Mace Head?

    NASA Astrophysics Data System (ADS)

    O'Dowd, C.; Ceburnis, D.; Ovadnevaite, J.; Vaishya, A.; Rinaldi, M.; Facchini, M. C.

    2014-10-01

    Atmospheric aerosols have been sampled and characterised at the Mace Head north-east (NE) Atlantic atmospheric research station since 1958, with many interesting phenomena being discovered. However, with the range of new discoveries and scientific advances, there has been a range of concomitant criticisms challenging the representativeness of aerosol sampled at the station compared to that of aerosol over the pristine open-ocean. Two recurring criticisms relate to the lack of representativeness due to potentially enhanced coastal sources, possibly leading to artificially high values of aerosol concentrations, and to the influence of long-range transport of anthropogenic or continental aerosol and its potential dominance over, or perturbation of, a natural marine aerosol signal. Here, we review the results of previous experimental studies on marine aerosols over the NE Atlantic and at Mace Head with the aim of evaluating their representativeness relative to that of a pristine open-ocean aerosol, i.e. with negligible anthropogenic/continental influence. Particular focus is given to submicron organic matter (OM) aerosol. In summary, no correlation was found between OM and black carbon (BC) in marine air conforming to clean-air sampling criteria, either at BC levels of 0-15 or 15-50 ng m-3, suggesting that OM concentrations, up to observed peak values of 3.8 μg m-3, are predominantly natural in origin. Sophisticated carbon isotope analysis and aerosol mass spectral finger printing techniques corroborate the conclusion that there is a predominant natural source of OM, with 80% biogenic source apportionment being observed for general clean-air conditions, rising to ∼98% during specific primary marine organic plumes when peak OM mass concentrations > 3 μg m-3 are observed. Similarly, a maximum contribution of 20% OM mass coming from non-marine sources was established by dual carbon isotope analysis. Further, analysis of a series of experiments conducted at Mace Head

  14. Advanced source apportionment of size-resolved trace elements at multiple sites in London during winter

    NASA Astrophysics Data System (ADS)

    Visser, S.; Slowik, J. G.; Furger, M.; Zotter, P.; Bukowiecki, N.; Canonaco, F.; Flechsig, U.; Appel, K.; Green, D. C.; Tremper, A. H.; Young, D. E.; Williams, P. I.; Allan, J. D.; Coe, H.; Williams, L. R.; Mohr, C.; Xu, L.; Ng, N. L.; Nemitz, E.; Barlow, J. F.; Halios, C. H.; Fleming, Z. L.; Baltensperger, U.; Prévôt, A. S. H.

    2015-10-01

    Trace element measurements in PM10-2.5, PM2.5-1.0 and PM1.0-0.3 aerosol were performed with 2 h time resolution at kerbside, urban background and rural sites during the ClearfLo winter 2012 campaign in London. The environment-dependent variability of emissions was characterized using the Multilinear Engine implementation of the positive matrix factorization model, conducted on data sets comprising all three sites but segregated by size. Combining the sites enabled separation of sources with high temporal covariance but significant spatial variability. Separation of sizes improved source resolution by preventing sources occurring in only a single size fraction from having too small a contribution for the model to resolve. Anchor profiles were retrieved internally by analysing data subsets, and these profiles were used in the analyses of the complete data sets of all sites for enhanced source apportionment. A total of nine different factors were resolved (notable elements in brackets): in PM10-2.5, brake wear (Cu, Zr, Sb, Ba), other traffic-related (Fe), resuspended dust (Si, Ca), sea/road salt (Cl), aged sea salt (Na, Mg) and industrial (Cr, Ni); in PM2.5-1.0, brake wear, other traffic-related, resuspended dust, sea/road salt, aged sea salt and S-rich (S); and in PM1.0-0.3, traffic-related (Fe, Cu, Zr, Sb, Ba), resuspended dust, sea/road salt, aged sea salt, reacted Cl (Cl), S-rich and solid fuel (K, Pb). Human activities enhance the kerb-to-rural concentration gradients of coarse aged sea salt, typically considered to have a natural source, by 1.7-2.2. These site-dependent concentration differences reflect the effect of local resuspension processes in London. The anthropogenically influenced factors traffic (brake wear and other traffic-related processes), dust and sea/road salt provide further kerb-to-rural concentration enhancements by direct source emissions by a factor of 3.5-12.7. The traffic and dust factors are mainly emitted in PM10-2.5 and show strong

  15. Impact of gas/particle partitioning of semivolatile organic compounds on source apportionment with positive matrix factorization.

    PubMed

    Xie, Mingjie; Hannigan, Michael P; Barsanti, Kelley C

    2014-08-19

    To quantify and minimize the influence of gas/particle (G/P) partitioning on receptor-based source apportionment using particle-phase semivolatile organic compound (SVOC) data, positive matrix factorization (PMF) coupled with a bootstrap technique was applied to three data sets mainly composed of "measured-total" (measured particle- + gas-phase), "particle-only" (measured particle-phase) and "predicted-total" (measured particle-phase + predicted gas-phase) SVOCs to apportion carbonaceous aerosols. Particle- (PM2.5) and gas-phase SVOCs were collected using quartz fiber filters followed by PUF/XAD-4/PUF adsorbents and measured using gas chromatography-mass spectrometry (GC-MS). Concentrations of gas-phase SVOCs were also predicted from their particle-phase concentrations using absorptive partitioning theory. Five factors were resolved for each data set, and the factor profiles were generally consistent across the three PMF solutions. Using a previous source apportionment study at the same receptor site, those five factors were linked to summertime biogenic emissions (odd n-alkane factor), unburned fossil fuels (light SVOC factor), road dust and/or cooking (n-alkane factor), motor vehicle emissions (PAH factor), and lubricating oil combustion (sterane factor). The "measured-total" solution was least influenced by G/P partitioning and used as reference. Two out of the five factors (odd n-alkane and PAH factors) exhibited consistent contributions for "particle-only" vs "measured-total" and "predicted-total" vs "measured-total" solutions. Factor contributions of light SVOC and n-alkane factors were more consistent for "predicted-total" vs "measured-total" than "particle-only" vs "measured-total" solutions. The remaining factor (sterane factor) underestimated the contribution by around 50% from both "particle-only" and "predicted-total" solutions. The results of this study confirm that when measured gas-phase SVOCs are not available, "predicted-total" SVOCs should be used

  16. A hybrid source apportionment model integrating measured data and air quality model results - article no. D07301

    SciTech Connect

    Schichtel, B.A.; Malm, W.C.; Gebhart, K.A.; Barna, M.G.; Knipping, E.M.

    2006-04-04

    The Big Bend Regional Aerosol and Visibility (BRAVO) study was an intensive air quality study designed to understand the causes of haze in Big Bend National Park. Daily speciated fine aerosols were measured from July through October 1999 at 37 sites located mostly in Texas. In support of BRAVO, two chemical transport models (CTMs) were used to apportion particulate sulfate at Big Bend and other sites in Texas to sources in the eastern and western United States, Texas, Mexico, and the Carbon I and II coal-fired power plants, located 225 km southeast of Big Bend in Mexico. Analysis of the CTM source attribution results and comparison to results from receptor models revealed systematic biases. To reduce the multiplicative biases, a hybrid source apportionment model, based on inverse modeling, was developed that adjusted the initial CTM source contributions so the modeled sulfate concentrations optimally fit the measured data, resulting in refined daily source contributions. The method was tested using synthetic data and successfully reduced source attribution biases. The refined sulfate source attribution results reduced the initial eastern U.S. contribution to Big Bend, averaged over the BRAVO study period, from about 40% to about 30%, while Mexico's contribution increased from 24 - 32% about 40%. The contribution from the Carbon facility increased from similar to 14% to over 20%. The increase in Mexico's contribution is consistent with more recent SO{sub 2} emissions estimates that indicate that the BRAVO Mexican SO{sub 2} emissions were underestimated. Source attribution results for other monitoring sites in west Texas were similar to results at Big Bend.

  17. Source apportionment of fine particulate matter in the southeastern United States

    SciTech Connect

    Sangil Lee; Armistead G. Russell; Karsten Baumann

    2007-09-15

    Particulate matter (PM) less than 2.5 {mu}m in size (PM2.5) source apportionment by chemical mass balance receptor modeling was performed to enhance regional characterization of source impacts in the southeastern United States. Secondary particles, such as NH{sub 4}HSO{sub 4}, (NH{sub 4}){sub 2}SO{sub 4}, NH{sub 4}NO{sub 3}, and secondary organic carbon (OC) (SOC), formed by atmospheric photochemical reactions, contribute the majority ({gt} 50%) of ambient PM2.5 with strong seasonality. Source apportionment results indicate that motor vehicle and biomass burning are the two main primary sources in the southeast, showing relatively more motor vehicle source impacts rather than biomass burning source impacts in populated urban areas and vice versa in less urbanized areas. Spatial distributions of primary source impacts show that each primary source has distinctively different spatial source impacts. For coal combustion, higher concentrations occur in areas close to source and are highest at Jefferson (Birmingham), AL where industrial facilities use coal for fuel. Pulp and paper mills contribute high sources along the coast where oil combustion contribution is also high. Results also find impacts from shipping activities along the coast. Spatiotemporal correlations indicate that secondary particles are more regionally distributed, as are biomass burning and dust, whereas impacts of other primary sources are more local. 60 refs., 7 figs., 1 tab.

  18. Source apportionment of airborne fine particulate matter in an underground mine.

    PubMed

    McDonald, Jacob D; Zielinska, Barbara; Sagebiel, John C; McDaniel, Mark R; Mousset-Jones, Pierre

    2003-04-01

    The chemical mass balance source apportionment technique was applied to an underground gold mine to assess the contribution of diesel exhaust, rock dust, oil mists, and cigarette smoke to airborne fine (<2.5 microm) particulate matter (PM). Apportionments were conducted in two locations in the mine, one near the mining operations and one near the exit of the mine where the ventilated mine air was exhausted. Results showed that diesel exhaust contributed 78-98% of the fine particulate mass and greater than 90% of the fine particle carbon, with rock dust making up the remainder. Oil mists and cigarette smoke contributions were below detection limits for this study. The diesel exhaust fraction of the total fine PM was higher than the recently implemented mine air quality standards based on total carbon at both sample locations in the mine. PMID:12708502

  19. Spallation Neutron Source Availability Top-Down Apportionment Using Characteristic Factors and Expert Opinion

    SciTech Connect

    Haire, M.J.; Schryver, J.C.

    1999-10-01

    Apportionment is the assignment of top-level requirements to lower tier elements of the overall facility. A method for apportioning overall facility availability requirements among systems and subsystems is presented. Characteristics that influence equipment reliability and maintainability are discussed. Experts, using engineering judgment, scored each characteristic for each system whose availability design goal is to be established. The Analytic Hierarchy Process (AHP) method is used to produce a set of weighted rankings for each characteristic for each alternative system. A mathematical model is derived which incorporates these weighting factors. The method imposes higher availability requirements on those systems in which an incremental increase in availability is easier to achieve, and lower availability requirements where greater availability is more difficult and costly. An example is given of applying this top-down apportionment methodology to the Spallation Neutron Source (SNS) facility.

  20. Size-resolved source apportionment of carbonaceous particulate matter in urban and rural sites in central California

    NASA Astrophysics Data System (ADS)

    Ham, Walter A.; Kleeman, Michael J.

    2011-08-01

    Very little is currently known about the relationship between exposure to different sources of ambient ultrafine particles (PM 0.1) and human health effects. If human health effects are enhanced by PM 0.1's ability to cross cell membranes, then more information is needed describing the sources of ultrafine particles that are deposited in the human respiratory system. The current study presents results for the source apportionment of airborne particulate matter in six size fractions smaller than 1.8 μm particle diameter including ultrafine particles (PM 0.1) in one of the most polluted air basins in the United States. Size-resolved source apportionment results are presented at an urban site and rural site in central California's heavily polluted San Joaquin Valley during the winter and summer months using a molecular marker chemical mass balance (MM-CMB) method. Respiratory deposition calculations for the size-resolved source apportionment results are carried out with the Multiple Path Particle Dosimetry Model ( MPPD v 2.0), including calculations for ultrafine (PM 0.1) source deposition. Diesel engines accounted for the majority of PM 0.1 and PM 1.8 EC at both the urban and rural sampling locations during both summer and winter seasons. Meat cooking accounted for 33-67% and diesel engines accounted for 15-21% of the PM 0.1 OC at Fresno. Meat cooking accounted for 22-26% of the PM 0.1 OC at the rural Westside location, while diesel engines accounted for 8-9%. Wood burning contributions to PM 0.1 OC increased to as much as 12% of PM 0.1 OC during the wintertime. The modest contribution of wood smoke reflects the success of emissions control programs over the past decade. In contrast to PM 0.1, PM 1.8 OC had a higher fraction of unidentified source contributions (68-85%) suggesting that this material is composed of secondary organic aerosol (SOA) or primary organic aerosol (POA) that has been processed by atmospheric chemical reactions. Meat cooking was the largest

  1. Application of a source apportionment model in consideration of volatile organic compounds in an urban stream

    USGS Publications Warehouse

    Asher, W.E.; Luo, W.; Campo, K.W.; Bender, D.A.; Robinson, K.W.; Zogorski, J.S.; Pankow, J.F.

    2007-01-01

    Position-dependent concentrations of trichloroethylene and methyl-tert-butyl ether are considered for a 2.81-km section of the Aberjona River in Massachusetts, USA. This river flows through Woburn and Winchester (Massachusetts, USA), an area that is highly urbanized, has a long history of industrial activities dating to the early 1800s, and has gained national attention because of contamination from chlorinated solvent compounds in Woburn wells G and H. The river study section is in Winchester and begins approximately five stream kilometers downstream from the Woburn wells superfund site. Approximately 300 toxic release sites are documented in the watershed upstream from the terminus of the study section. The inflow to the river study section is considered one source of contamination. Other sources are the atmosphere, a tributary flow, and groundwater flows entering the river; the latter are categorized according to stream zone (1, 2, 3, etc.). Loss processes considered include outflows to groundwater and water-to-atmosphere transfer of volatile compounds. For both trichloroethylene and methyl-rerf-butyl ether, degradation is neglected over the timescale of interest. Source apportionment fractions with assigned values ??inflow, ??1, ??2, ??3, etc. are tracked by a source apportionment model. The strengths of the groundwater and tributary sources serve as fitting parameters when minimizing a reduced least squares statistic between water concentrations measured during a synoptic study in July 2001 versus predictions from the model. The model fits provide strong evidence of substantial unknown groundwater sources of trichloroethylene and methyl-tert-butyl ether amounting to tens of grams per day of trichloroethylene and methyl-tert-butyl ether in the river along the study section. Modeling in a source apportionment manner can be useful to water quality managers allocating limited resources for remediation and source control. ?? 2007 SETAC.

  2. Microbial water pollution: a screening tool for initial catchment-scale assessment and source apportionment.

    PubMed

    Kay, D; Anthony, S; Crowther, J; Chambers, B J; Nicholson, F A; Chadwick, D; Stapleton, C M; Wyer, M D

    2010-11-01

    The European Union Water Framework Directive requires that Management Plans are developed for individual River Basin Districts. From the point of view of faecal indicator organisms (FIOs), there is a critical need for screening tools that can provide a rapid assessment of the likely FIO concentrations and fluxes within catchments under base- and high-flow conditions, and of the balance ('source apportionment') between agriculture- and sewage-derived sources. Accordingly, the present paper reports on: (1) the development of preliminary generic models, using water quality and land cover data from previous UK catchment studies for assessing FIO concentrations, fluxes and source apportionment within catchments during the summer bathing season; (2) the calibration of national land use data, against data previously used in the models; and (3) provisional FIO concentration and source-apportionment assessments for England and Wales. The models clearly highlighted the crucial importance of high-flow conditions for the flux of FIOs within catchments. At high flow, improved grassland (and associated livestock) was the key FIO source; FIO loadings derived from catchments with high proportions of improved grassland were shown to be as high as from urbanized catchments; and in many rural catchments, especially in NW and SW England and Wales, which are important areas of lowland livestock (especially dairy) farming, ≥ 40% of FIOs was assessed to be derived from agricultural sources. In contrast, under base-flow conditions, when there was little or no runoff from agricultural land, urban (i.e. sewerage-related) sources were assessed to dominate, and even in rural areas the majority of FIOs were attributed to urban sources. The results of the study demonstrate the potential of this type of approach, particularly in light of climate change and the likelihood of more high-flow events, in underpinning informed policy development and prioritization of investment. PMID:19717181

  3. Application of a source apportionment model in consideration of volatile organic compounds in an urban stream.

    PubMed

    Asher, William E; Luo, Wentai; Campo, Kimberly W; Bender, David A; Robinson, Keith W; Zogorski, John S; Pankow, James F

    2007-08-01

    Position-dependent concentrations of trichloroethylene and methyl-tert-butyl ether are considered for a 2.81-km section of the Aberjona River in Massachusetts, USA. This river flows through Woburn and Winchester (Massachusetts, USA), an area that is highly urbanized, has a long history of industrial activities dating to the early 1800s, and has gained national attention because of contamination from chlorinated solvent compounds in Woburn wells G and H. The river study section is in Winchester and begins approximately five stream kilometers downstream from the Woburn wells superfund site. Approximately 300 toxic release sites are documented in the watershed upstream from the terminus of the study section. The inflow to the river study section is considered one source of contamination. Other sources are the atmosphere, a tributary flow, and groundwater flows entering the river; the latter are categorized according to stream zone (1, 2, 3, etc.). Loss processes considered include outflows to groundwater and water-to-atmosphere transfer of volatile compounds. For both trichloroethylene and methyl-tert-butyl ether, degradation is neglected over the timescale of interest. Source apportionment fractions with assigned values alphainflow, alpha2, alpha3, etc. are tracked by a source apportionment model. The strengths of the groundwater and tributary sources serve as fitting parameters when minimizing a reduced least squares statistic between water concentrations measured during a synoptic study in July 2001 versus predictions from the model. The model fits provide strong evidence of substantial unknown groundwater sources of trichloroethylene and methyl-tert-butyl ether amounting to tens of grams per day of trichloroethylene and methyl-tert-butyl ether in the river along the study section. Modeling in a source apportionment manner can be useful to water quality managers allocating limited resources for remediation and source control. PMID:17702332

  4. Two Model-Based Methods for Policy Analyses of Fine Particulate Matter Control in China: Source Apportionment and Source Sensitivity

    NASA Astrophysics Data System (ADS)

    Li, X.; Zhang, Y.; Zheng, B.; Zhang, Q.; He, K.

    2013-12-01

    Anthropogenic emissions have been controlled in recent years in China to mitigate fine particulate matter (PM2.5) pollution. Recent studies show that sulfate dioxide (SO2)-only control cannot reduce total PM2.5 levels efficiently. Other species such as nitrogen oxide, ammonia, black carbon, and organic carbon may be equally important during particular seasons. Furthermore, each species is emitted from several anthropogenic sectors (e.g., industry, power plant, transportation, residential and agriculture). On the other hand, contribution of one emission sector to PM2.5 represents contributions of all species in this sector. In this work, two model-based methods are used to identify the most influential emission sectors and areas to PM2.5. The first method is the source apportionment (SA) based on the Particulate Source Apportionment Technology (PSAT) available in the Comprehensive Air Quality Model with extensions (CAMx) driven by meteorological predictions of the Weather Research and Forecast (WRF) model. The second method is the source sensitivity (SS) based on an adjoint integration technique (AIT) available in the GEOS-Chem model. The SA method attributes simulated PM2.5 concentrations to each emission group, while the SS method calculates their sensitivity to each emission group, accounting for the non-linear relationship between PM2.5 and its precursors. Despite their differences, the complementary nature of the two methods enables a complete analysis of source-receptor relationships to support emission control policies. Our objectives are to quantify the contributions of each emission group/area to PM2.5 in the receptor areas and to intercompare results from the two methods to gain a comprehensive understanding of the role of emission sources in PM2.5 formation. The results will be compared in terms of the magnitudes and rankings of SS or SA of emitted species and emission groups/areas. GEOS-Chem with AIT is applied over East Asia at a horizontal grid

  5. Fine Particle Sources and Cardiorespiratory Morbidity: An Application of Chemical Mass Balance and Factor Analytical Source-Apportionment Methods

    PubMed Central

    Sarnat, Jeremy A.; Marmur, Amit; Klein, Mitchel; Kim, Eugene; Russell, Armistead G.; Sarnat, Stefanie E.; Mulholland, James A.; Hopke, Philip K.; Tolbert, Paige E.

    2008-01-01

    Background Interest in the health effects of particulate matter (PM) has focused on identifying sources of PM, including biomass burning, power plants, and gasoline and diesel emissions that may be associated with adverse health risks. Few epidemiologic studies, however, have included source-apportionment estimates in their examinations of PM health effects. We analyzed a time-series of chemically speciated PM measurements in Atlanta, Georgia, and conducted an epidemiologic analysis using data from three distinct source-apportionment methods. Objective The key objective of this analysis was to compare epidemiologic findings generated using both factor analysis and mass balance source-apportionment methods. Methods We analyzed data collected between November 1998 and December 2002 using positive-matrix factorization (PMF), modified chemical mass balance (CMB-LGO), and a tracer approach. Emergency department (ED) visits for a combined cardiovascular (CVD) and respiratory disease (RD) group were assessed as end points. We estimated the risk ratio (RR) associated with same day PM concentrations using Poisson generalized linear models. Results There were significant, positive associations between same-day PM2.5 (PM with aero-dynamic diameter ≤ 2.5 μm) concentrations attributed to mobile sources (RR range, 1.018–1.025) and biomass combustion, primarily prescribed forest burning and residential wood combustion, (RR range, 1.024–1.033) source categories and CVD-related ED visits. Associations between the source categories and RD visits were not significant for all models except sulfate-rich secondary PM2.5 (RR range, 1.012–1.020). Generally, the epidemiologic results were robust to the selection of source-apportionment method, with strong agreement between the RR estimates from the PMF and CMB-LGO models, as well as with results from models using single-species tracers as surrogates of the source-apportioned PM2.5 values. Conclusions Despite differences among the

  6. Do anthropogenic or coastal aerosol sources impact on a clean marine aerosol signature at Mace Head?

    NASA Astrophysics Data System (ADS)

    O'Dowd, C.; Ceburnis, D.; Ovadnevaite, J.; Rinaldi, M.; Facchini, M. C.

    2013-03-01

    Atmospheric aerosols have been sampled and characterised at the Mace Head North East (N.E.) Atlantic atmospheric research station since 1958, with many interesting phenomena being discovered. However, with the range of new discoveries and scientific advances, there has been a range of concomitant criticisms challenging the representativeness of aerosol sampled at the station to that of aerosol over the open ocean. Two recurring criticisms relate to the lack of representativeness due to enhanced coastal sources, thereby leading to artificially high values to aerosol parameters, and to the influence of long-range transport of anthropogenic aerosol and its potential dominance over, or drowning-out of, a natural marine aerosol signal. Here we review the results of previous experimental studies into marine aerosols over the N.E. Atlantic and at Mace Head with the aim of evaluating their representativeness relative to that of an open ocean aerosol with negligible anthropogenic influence. Particular focus is given to organic matter (OM) aerosol. In summary, no correlation was found between OM and black carbon (BC) either at BC levels of 0-15 or 15-50 ng m-3, suggesting that OM concentrations up to peak values of 3.8 μg m-3 are predominantly natural in origin. Sophisticated carbon isotope analysis and aerosol mass spectral finger printing corroborate the natural source of OM with 80% biogenic source apportionment being observed for general clean air conditions, rising to 98% during specific primary marine organic plumes when peak concentrations >3 μg m-3 are observed. A range of other experiments are discussed which corroborate the dominance of a marine signal under Mace Head clean air criteria along. Further, analysis of a series of experiments conducted at Mace Head conclude that negligible coastal, surf zone, or tidal effects are discernible in the submicron size range for sampling heights of 7 m and above. The Mace Head clean air criteria ensures anthropogenic and

  7. Contribution Assessment of Regional Air Pollution over Northeast Asia using CMAQ Source Apportionment Tools

    NASA Astrophysics Data System (ADS)

    Choi, K.; Woo, J.; Kim, H.; Lee, J.; Kim, C.

    2011-12-01

    East Asia is one of the largest emission source regions in the world because of the large population and fast economic growth for several decades. Recent observation from space also demonstrates that emissions in East Asia - especially China - have been increased impressively since 1995. A number of regional scale transport studies using comprehensive 3D modeling system such as CMAQ have been conducted to understand transboundary air pollution. The contribution assessment using such a comprehensive modeling system, however, was not extensively investigated in this region. Air pollution contributions from multiple source types and regions over East Asia were examined using CMAQ based source apportionment tool off-line coupled with a meteorological model (WRF). The simulation was conducted for the entire year of 2009. The CMAQ ozone & particle precursor tagging methodologies (OPTM) source apportionment tool were applied in our study. An anthropogenic emissions inventory and processing methodology have been developed in support of the source-receptor modeling study in East Asia region. Emissions from open biomass burning and biogenic source were also estimated to support air quality contributions assessment from various sources and source types. Remote sensing-based atmosphere information and ground based monitoring data has been included to evaluate the simulation results. The results of our analysis will be presented at the conference.

  8. Temporal trend and source apportionment of water pollution in different functional zones of Qiantang River, China.

    PubMed

    Su, Shiliang; Li, Dan; Zhang, Qi; Xiao, Rui; Huang, Fang; Wu, Jiaping

    2011-02-01

    The increasingly serious river water pollution in developing countries poses great threat to environmental health and human welfare. The assignment of river function to specific uses, known as zoning, is a useful tool to reveal variations of water environmental adaptability to human impact. Therefore, characterizing the temporal trend and identifying responsible pollution sources in different functional zones could greatly improve our knowledge about human impacts on the river water environment. The aim of this study is to obtain a deeper understanding of temporal trends and sources of water pollution in different functional zones with a case study of the Qiantang River, China. Measurement data were obtained and pretreated for 13 variables from 41 monitoring sites in four categories of functional zones during the period 1996-2004. An exploratory approach, which combines smoothing and non-parametric statistical tests, was applied to characterize trends of four significant parameters (permanganate index, ammonia nitrogen, total cadmium and fluoride) accounting for differences among different functional zones identified by discriminant analysis. Aided by GIS, yearly pollution index (PI) for each monitoring site was further mapped to compare the within-group variations in temporal dynamics for different functional zones. Rotated principal component analysis and receptor model (absolute principle component score-multiple linear regression, APCS-MLR) revealed that potential pollution sources and their corresponding contributions varied among the four functional zones. Variations of APCS values for each site of one functional zone as well as their annual average values highlighted the uncertainties associated with cross space-time effects in source apportionment. All these results reinforce the notion that the concept of zoning should be taken seriously in water pollution control. Being applicable to other rivers, the framework of management-oriented source apportionment

  9. An integrated approach to assess heavy metal source apportionment in peri-urban agricultural soils.

    PubMed

    Huang, Ying; Li, Tingqiang; Wu, Chengxian; He, Zhenli; Japenga, Jan; Deng, Meihua; Yang, Xiaoe

    2015-12-15

    Three techniques (Isotope Ratio Analysis, GIS mapping, and Multivariate Statistical Analysis) were integrated to assess heavy metal pollution and source apportionment in peri-urban agricultural soils. The soils in the study area were moderately polluted with cadmium (Cd) and mercury (Hg), lightly polluted with lead (Pb), and chromium (Cr). GIS Mapping suggested Cd pollution originates from point sources, whereas Hg, Pb, Cr could be traced back to both point and non-point sources. Principal component analysis (PCA) indicated aluminum (Al), manganese (Mn), nickel (Ni) were mainly inherited from natural sources, while Hg, Pb, and Cd were associated with two different kinds of anthropogenic sources. Cluster analysis (CA) further identified fertilizers, waste water, industrial solid wastes, road dust, and atmospheric deposition as potential sources. Based on isotope ratio analysis (IRA) organic fertilizers and road dusts accounted for 74-100% and 0-24% of the total Hg input, while road dusts and solid wastes contributed for 0-80% and 19-100% of the Pb input. This study provides a reliable approach for heavy metal source apportionment in this particular peri-urban area, with a clear potential for future application in other regions. PMID:26257294

  10. Application of 14C analyses to source apportionment of carbonaceous PM 2.5 in the UK

    NASA Astrophysics Data System (ADS)

    Heal, Mathew R.; Naysmith, Philip; Cook, Gordon T.; Xu, Sheng; Duran, Teresa Raventós; Harrison, Roy M.

    2011-05-01

    Determination of the radiocarbon ( 14C) content of airborne particulate matter yields insight into the proportion of the carbonaceous material derived from fossil and contemporary carbon sources. Daily samples of PM 2.5 were collected by high-volume sampler at an urban background site in Birmingham, UK, and the fraction of 14C in both the total carbon, and in the organic and elemental carbon fractions, determined by two-stage combustion to CO 2, graphitisation and quantification by accelerator mass spectrometry. OC and EC content was also determined by Sunset Analyzer. The mean fraction contemporary TC in the PM 2.5 samples was 0.50 (range 0.27-0.66, n = 26). There was no seasonality to the data, but there was a positive trend between fraction contemporary TC and magnitude of SOC/TC ratio and for the high values of these two parameters to be associated with air-mass back trajectories arriving in Birmingham from over land. Using a five-compartment mass balance model on fraction contemporary carbon in OC and EC, the following average source apportionment for the TC in these PM 2.5 samples was derived: 27% fossil EC; 20% fossil OC; 2% biomass EC; 10% biomass OC; and 41% biogenic OC. The latter category will comprise, in addition to BVOC-derived SOC, other non-combustion contemporary carbon sources such as biological particles, vegetative detritus, humic material and tyre wear. The proportion of total PM 2.5 at this location estimated to derive from BVOC-derived secondary organic aerosol was 9-29%. The findings from this work are consistent with those from elsewhere in Europe and support the conclusion of a significant and ubiquitous contribution from non-fossil biogenic sources to the carbon in terrestrial aerosol.

  11. SOURCE APPORTIONMENT OF EXPOSURES TO VOLATILE ORGANIC COMPOUNDS: I. EVALUATION OF RECEPTOR MODELS USING SIMULATED EXPOSURE DATA. (R826788)

    EPA Science Inventory

    Four receptor-oriented source apportionment models were evaluated by applying them to simulated personal exposure data for select volatile organic compounds (VOCs) that were generated by Monte Carlo sampling from known source contributions and profiles. The exposure sources mo...

  12. Source apportionment of PM2.5 in top polluted cities in Hebei, China using the CMAQ model

    NASA Astrophysics Data System (ADS)

    Wang, Litao; Wei, Zhe; Wei, Wei; Fu, Joshua S.; Meng, Chenchen; Ma, Simeng

    2015-12-01

    Hebei has been recognized as one of the most polluted provinces in China, characterized by extremely high concentrations of fine particulate matter (PM2.5) in many of its cities, especially those located in the southern area of the province and highly potentially northward transported to Beijing. Source apportionment of PM2.5 is the basis and prerequisite of an effective control strategy. In this study, the Mesoscale Modeling System Generation 5 (MM5) and the Models-3/Community Multiscale Air Quality (CMAQ) modeling system are applied to East Asia and North China at 36- and 12-km horizontal grid resolutions, and the source apportionment of PM2.5 in the three top polluted cities in Hebei, i.e., Shijiazhuang, Xingtai, and Handan, is performed using the Brute-Force method. It is concluded that the regional source contributions to PM2.5 are 27.9% in Shijiazhuang, 46.6% in Xingtai, and 40.4% in Handan. The major local contributors are industrial, domestic and agricultural sources in all the three cities with the contributions of 39.8%, 15.8%, and 10.6% in Shijiazhuang, 30.5%, 13.6%, and 6.9% in Xingtai, 35.9%, 13.5%, and 6.2% in Handan, respectively. As to the secondary aerosols of sulfate (SO42-), nitrate (NO3-), and ammonium (NH4+) in PM2.5, which are important chemical species in PM2.5 (about 30-40% in PM2.5) and cannot be further apportioned by receptor models, the regional source contributions to the total concentrations of SO42-, NO3-, and NH4+ are 40.9%, 62.0%, and 59.1% in Shijiazhuang, Xingtai, and Handan, respectively. The local industrial, domestic and agricultural contributions to those are 23.7%, 6.6%, and 29.8% in total in Shijiazhuang, 17.5%, 5.0%, and 17.7% in Xingtai, and 20.6%, 4.8%, and 17.8% in Handan, respectively. The regional joint controls of air pollution are more important in Xingtai and Handan than in Shijiazhuang, and the emission controls of agricultural sources need to be further considered in the future policy.

  13. PM2.5 source apportionment: reconciling receptor models for U.S. nonurban and urban long-term networks.

    PubMed

    Chen, L W Antony; Watson, John G; Chow, Judith C; DuBois, Dave W; Herschberger, Lisa

    2011-11-01

    Chemical mass balance (CMB) and trajectory receptor models were applied to speciated particulate matter with aerodynamic diameter < or =2.5 microm (PM2.5) measurements from Speciation Trends Network (STN; part of the Chemical Speciation Network [CSN]) and Interagency Monitoring of Protected Visual Environments (IMPROVE) monitoring network across the state of Minnesota as part of the Minnesota PM2.5 Source Apportionment Study (MPSAS). CMB equations were solved by the Unmix, positive matrix factorization (PMF), and effective variance (EV) methods, giving collective source contribution and uncertainty estimates. Geological source profiles developed from local dust materials were either incorporated into the EV-CMB model or used to verify factors derived from Unmix and PMF. Common sources include soil dust, calcium (Ca)-rich dust, diesel and gasoline vehicle exhausts, biomass burning, secondary sulfate, and secondary nitrate. Secondary sulfate and nitrate aerosols dominate PM2.5 mass (50-69%). Mobile sources outweigh area sources at urban sites, and vice versa at rural sites due to traffic emissions. Gasoline and diesel contributions can be separated using data from the STN, despite significant uncertainties. Major differences between MPSAS and earlier studies on similar environments appear to be the type and magnitude of stationary sources, but these sources are generally minor (<7%) in this and other studies. Ensemble back-trajectory analysis shows that the lower Midwestern states are the predominant source region for secondary ammoniated sulfate in Minnesota. It also suggests substantial contributions of biomass burning and soil dust from out-of-state on occasions, although a quantitative separation of local and regional contributions was not achieved in the current study. Supplemental materials are available for this article. Go to the publisher's online edition of the Journal of the Air & Waste Management Association for a summary of input data, Unmix and PMF

  14. Estimation of organic carbon blank values and error structures of the speciation trends network data for source apportionment

    SciTech Connect

    Eugene Kim; Philip K. Hopke; Youjun Qin

    2005-08-01

    Because the particulate organic carbon (OC) concentrations reported in U.S. Environment Protection Agency Speciation Trends Network (STN) data were not blank corrected, the OC blank concentrations were estimated using the intercept in particulate matter {lt} 2.5 {mu}m in aerodynamic diameter (PM2.5) regression against OC concentrations. The estimated OC blank concentrations ranged from 1 to 2.4 {mu}g/m{sup 3} showing higher values in urban areas for the 13 monitoring sites in the northeastern United States. In the STN data, several different samplers and analyzers are used, and various instruments show different method detection limit (MDL) values, as well as errors. A comprehensive set of error structures that would be used for numerous source apportionment studies of STN data was estimated by comparing a limited set of measured concentrations and their associated uncertainties. To examine the estimated error structures and investigate the appropriate MDL values, PM2.5 samples collected at a STN site in Burlington, VT, were analyzed through the application of the positive matrix factorization. A total of 323 samples that were collected between December 2000 and December 2003 and 49 species based on several variable selection criteria were used, and eight sources were successfully identified in this study with the estimated error structures and min values among different MDL values from the five instruments: secondary sulfate aerosol (41%) identified as the result of emissions from coal-fired power plants, secondary nitrate aerosol (20%), airborne soil (15%), gasoline vehicle emissions (7%), diesel emissions (7%), aged sea salt (4%), copper smelting (3%), and ferrous smelting (2%). Time series plots of contributions from airborne soil indicate that the highly elevated impacts from this source were likely caused primarily by dust storms.

  15. Source apportionment of ambient fine particulate matter in Dearborn, Michigan, using hourly resolved PM chemical composition data.

    PubMed

    Pancras, Joseph Patrick; Landis, Matthew S; Norris, Gary A; Vedantham, Ram; Dvonch, J Timothy

    2013-03-15

    High time-resolution aerosol sampling was conducted for one month during July-August 2007 in Dearborn, MI, a non-attainment area for fine particulate matter (PM2.5) National Ambient Air Quality Standards (NAAQS). Measurements of more than 30 PM2.5 species were made using a suite of semi-continuous sampling and monitoring instruments. Dynamic variations in the sub-hourly concentrations of source 'marker' elements were observed when discrete plumes from local sources impacted the sampling site. Hourly averaged PM2.5 composition data for 639 samples were used to identify and apportion PM2.5 emission sources using the multivariate receptor modeling techniques EPA Positive Matrix Factorization (PMF) v4.2 and EPA Unmix v6.0. Source contribution estimates from PMF and Unmix were then evaluated using the Sustained Wind Instance Method (SWIM), which identified plausible source origins. Ten sources were identified by both PMF and Unmix: (1) secondary sulfate, (2) secondary nitrate characterized by a significant diurnal trend, (3) iron and steel production, (4) a potassium-rich factor attributable to iron/steel slag waste processing, (5) a cadmium-rich factor attributable to incineration, (6) an oil refinery characterized by La/Ce>1 specific to south wind, (7) oil combustion, (8) coal combustion, (9) motor vehicles, and (10) road dust enriched with organic carbon. While both models apportioned secondary sulfate, oil refinery, and oil combustion PM2.5 masses closely, the mobile and industrial source apportionments differed. Analyses were also carried out to help infer time-of-day variations in the contributions of local sources. PMID:23302684

  16. Source apportionment: findings from the US supersites program

    SciTech Connect

    John G. Watson; L.-W. Antony Chen; Judith C. Chow; Prakash Doraiswamy; Douglas H. Lowenthal

    2008-02-15

    Receptor models are used to identify and quantify source contributions to particulate matter and volatile organic compounds based on measurements of many chemical components at receptor sites. These components are selected based on their consistent appearance in some source types and their absence in others. UNMIX, positive matrix factorization (PMF), and effective variance are different solutions to the chemical mass balance (CMB) receptor model equations and are implemented on available software. In their more general form, the CMB equations allow spatial, temporal, transport, and particle size profiles to be combined with chemical source profiles for improved source resolution. Although UNMIX and PMF do not use source profiles explicitly as input data, they still require measured profiles to justify their derived source factors. The U.S. Supersites Program provided advanced datasets to apply these CMB solutions in different urban areas. Still lacking are better characterization of source emissions, new methods to estimate profile changes between source and receptor, and systematic sensitivity tests of deviations from receptor model assumptions. 154 refs.

  17. RECENT APPLICATIONS OF SOURCE APPORTIONMENT METHODS AND RELATED NEEDS

    EPA Science Inventory

    Traditional receptor modeling studies have utilized factor analysis (like principal component analysis, PCA) and/or Chemical Mass Balance (CMB) to assess source influences. The limitations with these approaches is that PCA is qualitative and CMB requires the input of source pr...

  18. Source apportionment of PM2.5 in Seoul, Korea

    NASA Astrophysics Data System (ADS)

    Heo, J.-B.; Hopke, P. K.; Yi, S.-M.

    2008-12-01

    PM2.5 samples were collected at a centrally located urban monitoring site in Seoul, Korea, every third day from March 2003 to December 2006 and analyzed for their chemical constituents. Sources were identified using Positive Matrix Factorization (PMF). A total of 393 samples were obtained during the sampling period, and 20 chemical species were measured. Nine PM2.5 sources were identified providing physically realistic profiles and interesting insights into the source contributions to the ambient mass concentrations. The major sources of PM2.5 were secondary nitrate (20%), secondary sulfate (20%), gasoline-fueled vehicles (17%), and biomass burning (12%), with lesser contributions from diesel emissions (8%), soil (7%), industry (6%), road salt and two-stroke engine (5%), and aged sea salt (2%). PM2.5 levels in Seoul were influenced by both local urban activities and regional-scale transport. Conditional Probability Function (CPF) results identified possible source directions of local sources such as motor vehicles (gasoline and diesel), industry, and road salt. Potential Source Contribution Function (PSCF) results showed that possible source areas contributing to the elevated secondary particle concentrations (sulfate and nitrate) in Seoul to be the major industrial areas in China.

  19. Radon source apportionment in the home, dosimetry and risk modeling. Final report, 1993--1997

    SciTech Connect

    Harley, N.H.

    1998-08-04

    This research covered the following 3 topics in 4 years: (1) the source apportionment of {sup 222}Rn in the home; (2) the internal bronchial dosimetry of inhaled {sup 222}Rn decay products; and (3) the lung cancer risk from inhalation of the short lived decay products of {sup 222}Rn. A 4th year of support was appended to this grant with a switch in research effort to determine a method for long term measurement of the particle size distribution of the short lived decay products in homes.

  20. Mass closure and source apportionment of PM2.5 by Positive Matrix Factorization analysis in urban Mediterranean environment

    NASA Astrophysics Data System (ADS)

    Mantas, E.; Remoundaki, E.; Halari, I.; Kassomenos, P.; Theodosi, C.; Hatzikioseyian, A.; Mihalopoulos, N.

    2014-09-01

    A systematic monitoring of PM2.5 was carried out during a period of three years (from February 2010 to April 2013) at an urban site, at the National Technical University of Athens campus. Two types of 24-h PM2.5 samples have been collected: 271 samples on PTFE and 116 samples on quartz filters. Daily PM2.5 concentrations were determined for both types of samples. Total sulfur, crustal origin elements and elements of a major crustal component (Al, Si, Fe, Ca, K, Mg, Ti) trace elements (Zn, Pb, Cu, Ni, P, V, Cr, Mn) and water soluble ions (Cl-, NO3-, SO42-, Na+, K+, NH4+, Ca2+, Mg2+) were determined on the PTFE samples. Organic carbon (OC), elemental carbon (EC) and water soluble ions were determined on the quartz samples. For the mass closure six components were considered: Secondary Inorganic Aerosol (SIA), Organic Matter (OM), Elemental Carbon (EC), Dust, Mineral anthropogenic component (MIN) and Sea Salt (SS). SIA and OM contributed in the mass of PM2.5 almost equally: 30-36% and 30% respectively. EC, SS and MIN accounted for 5, 4 and 3% respectively of the total PM2.5 mass. Dust accounted for about 3-5% in absence of dust transport event and reached a much higher percentage in case of dust transport event. These contributions justify at least 80% of the PM2.5 mass. Source apportionment analysis has been performed by Positive Matrix Factorization. The combination of the PMF results obtained by both data sets lead to the definition of six factors: 1. SO42-, NH4+, OC (industrial/regional sources, secondary aerosol) 2. EC, OC, K and trace metals (traffic and heating by biomass burning, locally emitted aerosol). 3. Ca, EC, OC and trace metals (urban-resuspended road dust reflecting exhaust emissions), 4. Secondary nitrates 5. Na, Cl (marine source) 6. Si, Al, Ti, Ca, Fe (Dust transported from Sahara). These factors reflect not only main sources contributions but also underline the key role of atmospheric dynamics and aerosol ageing processes in this Mediterranean

  1. AIRUSE-LIFE+: a harmonized PM speciation and source apportionment in five southern European cities

    NASA Astrophysics Data System (ADS)

    Amato, Fulvio; Alastuey, Andrés; Karanasiou, Angeliki; Lucarelli, Franco; Nava, Silvia; Calzolai, Giulia; Severi, Mirko; Becagli, Silvia; Gianelle, Vorne L.; Colombi, Cristina; Alves, Celia; Custódio, Danilo; Nunes, Teresa; Cerqueira, Mario; Pio, Casimiro; Eleftheriadis, Konstantinos; Diapouli, Evangelia; Reche, Cristina; Cruz Minguillón, María; Manousakas, Manousos-Ioannis; Maggos, Thomas; Vratolis, Stergios; Harrison, Roy M.; Querol, Xavier

    2016-03-01

    The AIRUSE-LIFE+ project aims at characterizing similarities and heterogeneities in particulate matter (PM) sources and contributions in urban areas from southern Europe. Once the main PMx sources are identified, AIRUSE aims at developing and testing the efficiency of specific and non-specific measures to improve urban air quality. This article reports the results of the source apportionment of PM10 and PM2.5 conducted at three urban background sites (Barcelona, Florence and Milan, BCN-UB, FI-UB and MLN-UB), one suburban background site (Athens, ATH-SUB) and one traffic site (Porto, POR-TR). After collecting 1047 PM10 and 1116 PM2.5 24 h samples during 12 months (from January 2013 on) simultaneously at the five cities, these were analysed for the contents of OC, EC, anions, cations, major and trace elements and levoglucosan. The USEPA PMF5 receptor model was applied to these data sets in a harmonized way for each city. The sum of vehicle exhaust (VEX) and non-exhaust (NEX) contributes between 3.9 and 10.8 µg m-3 (16-32 %) to PM10 and 2.3 and 9.4 µg m-3 (15-36 %) to PM2.5, although a fraction of secondary nitrate is also traffic-related but could not be estimated. Important contributions arise from secondary particles (nitrate, sulfate and organics) in PM2.5 (37-82 %) but also in PM10 (40-71 %), mostly at background sites, revealing the importance of abating gaseous precursors in designing air quality plans. Biomass burning (BB) contributions vary widely, from 14-24 % of PM10 in POR-TR, MLN-UB and FI-UB, 7 % in ATH-SUB, to < 2 % in BCN-UB. In PM2.5, BB is the second most important source in MLN-UB (21 %) and in POR-TR (18 %), the third one in FI-UB (21 %) and ATH-SUB (11 %), but is again negligible (< 2 %) in BCN-UB. This large variability among cities is mostly due to the degree of penetration of biomass for residential heating. In Barcelona natural gas is very well supplied across the city and is used as fuel in 96 % of homes, while in other cities, PM levels

  2. Source apportionment of PM2.5 in Seoul, Korea

    NASA Astrophysics Data System (ADS)

    Heo, J.-B.; Hopke, P. K.; Yi, S.-M.

    2009-07-01

    PM2.5 samples were collected at a centrally located urban monitoring site in Seoul, Korea, every third day from March 2003 to December 2006 and analyzed for their chemical constituents. Sources were identified using positive matrix factorization (PMF). A total of 393 samples were obtained during the sampling period, and 20 chemical species were measured. Nine PM2.5 source categories were identified providing physically realistic profiles and interesting insights into the source contributions to the ambient mass concentrations. The major contributors of PM2.5 were secondary nitrate (20.9%), secondary sulfate (20.5%), gasoline-fueled vehicles (17.2%), and biomass burning (12.1%), with lesser contributions from diesel emissions (8.1%), soil (7.4%), industry (6.7%), road salt and two-stroke vehicles (5.1%), and aged sea salt (2.2%). PM2.5 levels in Seoul were influenced by both local urban activities and regional-scale transport. Conditional probability function (CPF) results identified possible source directions of local sources such as motor vehicles (gasoline and diesel), industry, and road salt. Potential source contribution function (PSCF) results showed that possible source areas contributing to the elevated secondary particle concentrations (sulfate and nitrate) in Seoul to be the major industrial areas in China.

  3. Source apportionment of ambient volatile organic compounds in Hong Kong.

    PubMed

    Lau, Alexis Kai Hon; Yuan, Zibing; Yu, Jian Zhen; Louie, Peter K K

    2010-09-01

    Volatile organic compounds (VOCs) were measured at four stations with different environments in Hong Kong (HK) during two sampling campaigns. Positive matrix factorization was applied to characterize major VOC sources in HK. Nine sources were identified, and the spatial and seasonal variations of their contributions were derived. The most significant local VOC sources are vehicle and marine vessel exhausts or liquefied petroleum gas (LPG) at different stations. Vehicle- and marine vessel-related sources accounted for 2.9-12.7ppbv in 2002-2003 and increased to 4.3-15.2ppbv in 2006-2007. Different from the emission inventory, solvent-related sources only contributed 11- 19% at both sampling campaigns. Therefore, emission control from transport sector should be prioritized to alleviate ambient local VOC levels. Additionally, the contribution of aged VOC, which roughly represents contributions from regional and super-regional transport, also showed moderate increase during the four years, indicating cooperation with environmental authorities in the Pearl River Delta and beyond should be strengthened. All the anthropogenic sources contribute most to Yuen Long and least to Tap Mun. However, Tap Mun exhibited different trends in comparison with the other three stations, especially for sources of vehicle and marine vessel exhausts, LPG and paint solvents. When the local source contributions were incorporated with wind data to derive the directional dependences of sources, we may conclude that the rapid development of Yantian Container Terminal, the associated emissions from marine vessels around the Terminal and the on-site activities were likely responsible for the distinct VOC features at Tap Mun. The current impact from the Terminal is mainly concentrated in the northeastern corner of HK; however, it has the potential threat to other locations if the Terminal continues to expand in such a rapid speed in the coming years. More stringent VOC control measures on activities

  4. Source apportionment of PM2.5 in Incheon, Korea

    NASA Astrophysics Data System (ADS)

    Choi, J.; Ban, S.; Lee, C.; Yi, S.; Zoh, K.

    2011-12-01

    PM2.5 samples were collected at a centrally located urban monitoring site in Incheon, Korea, every third day from Jun 2009 to may 2010 and analyzed their chemical species. In this study, we investigated the source of PM2.5 using Positive Matrix Factorization(PMF), the source area from Potential Source Contribution Function (PSCF) and Conditional Probability Function(CPF), and characterized source variation among episode, non-episode, yellow sand events. Incheon, study site, is located at the mid-western tip of the Korean Peninsula with a population of 2.6 million people and area of 1029.4 km2, respectively. As a transportation hub, the city also holds the importance of meteological/geological aspect affecting the air quality of capital region, in that is prevailing westerlies zone and a air passageway from China to Japan passing through seoul, korea. In the study, the Four channel based on Annular Denuder System(ADS) were used for sample collection(URG co, USA). The filter samples were analyzed with respect to species type such as ion group, metal, and OC/EC compound using ion chromatography, ICP/MS, and NIOSH TOT method, respectively. The PM2.5 concentration was 43ug/m3 that is almost three times higher than the US NAAQS annual PM2.5 standard of 15ug/m3. Nine PM2.5 sources were resolved from PMF analysis that provided reasonable source profiles and interesting insights into the source contributions to the ambient mass concentrations. The major sources of PM2.5 were secondary nitrate(26.4%), secondary sulfate(17.3%), gasoline(16.4%), and residual oil combustion(13.5%), with lesser contributions from biomass burning (7.5%), road dust(6.9%), soil (5.5%), coal fire powerplant (4.0%), and free sea salt(2.4%). CPF results identified possible local source directions such as motor vehicles, free sea salt. PSCF results indicated that likely pollution areas increased secondary particle concentrations(sulfate and nitrate) in Incheon to be the major industrial areas in China

  5. Chemical speciation and source apportionment of Non-Methane Volatile Organic Compounds (NMVOCs) in a Middle Eastern country

    NASA Astrophysics Data System (ADS)

    Salameh, Therese; Sauvage, Stéphane; Afif, Charbel; Borbon, Agnès; Locoge, Nadine

    2014-05-01

    NMVOCs, emitted from various sources, are of particular interest since they contribute to the formation of tropospheric ozone, PAN and secondary organic aerosols resulting in negative impacts on human health, climate and on the environment. To identify abatement measures, a profound knowledge of emission sources and their composition is a prerequisite. Air pollution in the Middle East region remains difficult to assess and understand because of a lack of ground-based measurements and the limited information on NMVOC chemical speciation and source apportionment. Based on a large database of NMVOC observations obtained in Beirut, the capital of Lebanon (a developing country in the Middle East region, located in Western Asia on the eastern shore of the Mediterranean Sea), the overall objective of this work is to apportion the sources of NMVOCs encountered in Lebanon. First, source profiles were determined with field measurements close to the main potential emitters namely the road transport, gasoline vapour, power generation and solvent uses. The results obtained are compared to other studies held in other regions and are used to assess the emission inventory developed for Lebanon. Secondly, two intensive field campaigns were held in a receptor site in Beirut during summer 2011 and winter 2012 in order to obtain a large time resolved dataset. The PMF analysis of this dataset was applied to apportion anthropogenic sources in this area. In both seasons, combustion (road transport and power generation) and gasoline evaporation, especially in winter, were the main sources contributing to the NMVOCs in Beirut. The results will support model implementation especially by completing the emission inventory established for the year 2010 by Waked et al. 2012 according to the EEA/EMEP guidelines because of the lack of Lebanon-specific emission factor.

  6. Atmospheric polycyclic aromatic hydrocarbons in the urban environment: Occurrence, toxicity and source apportionment.

    PubMed

    Mishra, Nitika; Ayoko, Godwin A; Morawska, Lidia

    2016-01-01

    Polycyclic Aromatic Hydrocarbons (PAHs) represent a major class of toxic pollutants because of their carcinogenic and mutagenic characteristics. People living in urban areas are regularly exposed to PAHs because of abundance of their emission sources. Within this context, this study aimed to: (i) identify and quantify the levels of ambient PAHs in an urban environment; (ii) evaluate their toxicity; and (iii) identify their sources as well as the contribution of specific sources to measured concentrations. Sixteen PAHs were identified and quantified in air samples collected from Brisbane. Principal Component Analysis - Absolute Principal Component Scores (PCA-APCS) was used in order to conduct source apportionment of the measured PAHs. Vehicular emissions, natural gas combustion, petrol emissions and evaporative/unburned fuel were the sources identified; contributing 56%, 21%, 15% and 8% of the total PAHs emissions, respectively, all of which need to be considered for any pollution control measures implemented in urban areas. PMID:26428471

  7. Source apportionment of trace contaminants in urban sewer catchments.

    PubMed

    Comber, Sean; Gardner, Mike; Jones, Vera; Ellor, Brian

    2015-01-01

    Sampling and analysis of Water Framework Directive priority chemicals were undertaken in nine urban catchments across the UK. Over 9000 samples were collected from a number of different catchment sources including tap water, domestic waste water, surface water runoff, trade discharges, town centre and light industrial estate wastewaters. Determinands included trace metals, polyaromatic hydrocarbons (PAHs), persistent organic pollutants and a number of common pharmaceuticals. Loads of the chemicals from each catchment entering the local wastewater treatment works (WwTW) were estimated and were shown to be relatively consistent between different catchments, after taking population into account. A Monte Carlo mixing model was used to combine the concentrations and flows from the different catchment sources and to predict concentrations and loads entering the WwTW. Based on the model output, the significance of the different sources could be evaluated. The study highlighted the importance of domestic wastewater as a source of contaminants, including metals and trace organic substances (such as ethylenediaminetetraacetic acid (EDTA), bisphenol A, nonylphenol and tributyl tin (TBT)). Concentrations in trade discharges were important in some locations in the case of nonylphenol, EDTA, TBT, as well as for some metals such as copper, zinc and nickel. Contributions to the total load from town centre and light industrial estate sources were generally less than 10% of the total. PMID:25209673

  8. An inter-comparison of PM2.5 at urban and urban background sites: Chemical characterization and source apportionment

    NASA Astrophysics Data System (ADS)

    Cesari, D.; Donateo, A.; Conte, M.; Merico, E.; Giangreco, A.; Giangreco, F.; Contini, D.

    2016-06-01

    A measurement campaign was performed between 04/03/2013 and 17/07/2013 for simultaneous collection of PM2.5 samples in two nearby sites in southeastern Italy: an urban site and an urban background site. PM2.5 at the two sites were similar; however, the chemical composition and the contributions of the main sources were significantly different. The coefficients of divergence (CODs) showed spatial heterogeneity of EC (higher at the urban site because of traffic emissions) and of all metals. Major ions (NH4+, Na+, and SO42 -) and OC had low CODs, suggesting a homogeneous distribution of sea spray, secondary sulfate, and secondary organic matter (SOM = 1.6*OCsec, where OCsec is the secondary OC). The strong correlations between Na+ and Cl-, and the low Cl-/Na+ ratios, suggested the presence of aged sea spray with chloride depletion (about 79% of Cl-) and formation of sodium nitrate at both sites. In both sites, the non-sea-salt sulfate was about 97% of sulfate, and the strong correlation between SO42 - and NH4+ indicated that ammonium was present as ammonium sulfate. However, during advection of Saharan Dust, calcium sulfate was present rather than ammonium sulfate. The source apportionment was performed using the Positive Matrix Factorization comparing outputs of model EPA PMF 3.0 and 5.0 version. Six aerosol sources were identified at both sites: traffic, biomass burning, crustal-resuspended dust, secondary nitrate, marine aerosol, and secondary sulfate. The PMF3.0 model was not completely able, in these sites, to separate marine contribution from secondary nitrate and secondary sulfate from OC, underestimating the marine contribution and overestimating the secondary sulfate with respect to stoichiometric calculations. The application of specific constraints on PMF5.0 provided cleaner profiles, improving the comparison with stoichiometric calculations. The seasonal trends revealed larger biomass burning contributions during the cold period at both sites due to

  9. Ultrafine particles: exposure and source apportionment in 56 Danish homes.

    PubMed

    Bekö, Gabriel; Weschler, Charles J; Wierzbicka, Aneta; Karottki, Dorina Gabriela; Toftum, Jørn; Loft, Steffen; Clausen, Geo

    2013-09-17

    Particle number (PN) concentrations (10-300 nm in size) were continuously measured over a period of ~45 h in 56 residences of nonsmokers in Copenhagen, Denmark. The highest concentrations were measured when occupants were present and awake (geometric mean, GM: 22.3 × 10(3) cm(-3)), the lowest when the homes were vacant (GM: 6.1 × 10(3) cm(-3)) or the occupants were asleep (GM: 5.1 × 10(3) cm(-3)). Diary entries regarding occupancy and particle related activities were used to identify source events and apportion the daily integrated exposure among sources. Source events clearly resulted in increased PN concentrations and decreased average particle diameter. For a given event, elevated particle concentrations persisted for several hours after the emission of fresh particles ceased. The residential daily integrated PN exposure in the 56 homes ranged between 37 × 10(3) and 6.0 × 10(6) particles per cm(3)·h/day (GM: 3.3 × 10(5) cm(-3)·h/day). On average, ~90% of this exposure occurred outside of the period from midnight to 6 a.m. Source events, especially candle burning, cooking, toasting, and unknown activities, were responsible on average for ~65% of the residential integrated exposure (51% without the unknown activities). Candle burning occurred in half of the homes where, on average, it was responsible for almost 60% of the integrated exposure. PMID:23957328

  10. Carbonaceous aerosols from different tropical biomass burning sources

    NASA Astrophysics Data System (ADS)

    Cachier, Hélène; Brémond, Marie-Pierre; Buat-Ménard, Patrick

    1989-08-01

    FOLLOWING a repetitive pattern, biomass burning affects the intertropical belt on a continental scale during the dry season1. The importance of these anthropogenic activities with regard to carbonaceous-component emissions into the global atmosphere is now well recognized2-4. It has been suggested that large injections of black carbon aerosols from the Tropics are of potential importance for the radiative and chemical balance of the troposphere5-10. Studies on carbonaceous aerosols have indicated that, on an annual basis, the intensity of the emissions from tropical biomass burning could compare with that of emissions from fossil-fuel burning in industrial countries7,8. Also, results from combustion chamber experiments have determined the important range of the emission factor for both the organic and the black carbon components of the aerosol1-16. Following on from our earlier studies on total atmospheric particulate carbon (Ct) and isotopic composition (δ13C) (ref. 2), we now present new data on the black carbon content (Cb) of atmospheric particles sampled during the biomass-burning season in the wooden savannah of the Ivory Coast. The Cb/Ct ratio is generally lower than expected and highly variable. This variability indicates that there are drastic changes in source apportionment, which from our isotope studies may be ascribed to the variety of vegetation fuel and also to the mode of combustion. Therefore the Cb/Ct ratio can potentially discriminate biomass-burning emissions from different tropical ecosystems.

  11. Source apportionment using LOTOS-EUROS: module description and evaluation

    NASA Astrophysics Data System (ADS)

    Kranenburg, R.; Segers, A. J.; Hendriks, C.; Schaap, M.

    2013-06-01

    To design effective mitigation strategies, the origin of emissions which produce air pollutants needs to be known. Contributors to air pollutants can be emission sources, like road traffic or industry, but also be more specified to emission from one location or from a specified time. Chemistry transport models can be used to assess the origin of air pollution across a large domain. However, in traditional simulations the information on origin is lost and brute force scenario studies are performed to assess the origin. Alternatively, one can trace the origin of air pollutants throughout a simulation using a labeling approach. In this paper we document and demonstrate a newly developed labeling module for the chemistry transport model LOTOS-EUROS which tracks the source allocation for all particulate matter components and precursor gases. Dedicated simulations confirmed that the new module functions correctly. The new module provides more accurate information about the source contributions than using a brute force approach with scenario runs as the chemical regime remains unchanged. An important advantage of the new module is the reduction of computation costs and analysis work associated with the calculations. The new module was applied to assess the origin of particulate nitrate across the Netherlands. Averaged across the Dutch territory, the main contributions to nitrate are derived from road and non-road transport as well as power plants. Overall, only one-fifth of the concentration derived from sources located inside the country. The new technology enables new research directions as improved information on pollution origin is desired for policy support as well as scientific applications.

  12. Source apportionment of indoor PM10 in Elderly Care Centre.

    PubMed

    Almeida-Silva, M; Faria, T; Saraga, D; Maggos, T; Wolterbeek, H T; Almeida, S M

    2016-04-01

    Source contribution to atmospheric particulate matter (PM) has been exhaustively modelled. However, people spend most of their time indoors where this approach is less explored. This evidence worsens considering elders living in Elderly Care Centres, since they are more susceptible. The present study aims to investigate the PM composition and sources influencing elderly exposure. Two 2-week sampling campaigns were conducted-one during early fall (warm phase) and another throughout the winter (cold phase). PM10 were collected with two TCR-Tecora(®) samplers that were located in an Elderly Care Centre living room and in the correspondent outdoor. Chemical analysis of the particles was performed by neutron activation analysis for element characterization, by ion chromatography for the determination of water soluble ions and by a thermal optical technique for the measurement of organic and elemental carbon. Statistical analysis showed that there were no statistical differences between seasons and environments. The sum of the indoor PM10 components measured in this work explained 57 and 53 % of the total PM10 mass measured by gravimetry in warm and cold campaigns, respectively. Outdoor PM10 concentrations were significantly higher during the day than night (p value < 0.05), as well as Ca(2+), Fe, Sb and Zn. The contribution of indoor and outdoor sources was assessed by principal component analysis and showed the importance of the highways and the airport located less than 500 m from the Elderly Care Centre for both indoor and outdoor air quality. PMID:26758302

  13. Source apportionment using LOTOS-EUROS: module description and evaluation

    NASA Astrophysics Data System (ADS)

    Kranenburg, R.; Hendriks, C.; Schaap, M.; Segers, A.

    2012-11-01

    To design effective mitigation strategies the origin of air pollutants needs to be known. Chemistry transport models can be used to assess the origin of air pollution across a large domain. However, in traditional simulations the information on origin is lost and brute force scenario studies are performed to assess the origin. Alternatively, one can trace the origin of air pollutants throughout a simulation using a labeling approach. In this paper we document and demonstrate a newly developed labeling module for the chemistry transport model LOTOS-EUROS which tracks the source allocation for all particulate matter components and precursor gases. Dedicated simulations confirmed that the new module functions correctly. The new module provides more accurate information about the source contributions than using a brute force approach with scenario runs as the chemical regime remains unchanged. An important advantage of the new module is the reduction of computation costs and analysis work associated with the calculations. The new module was applied to assess the origin of particulate nitrate across the Netherlands. Averaged across the Dutch territory the main contributions to nitrate derive from road and non-road transport as well as power plants. Overall, only one-fifth of the concentration derived from sources located inside the country. The new technology enables new research directions as improved information on pollution origin is desired for policy support as well as scientific applications.

  14. Source apportionment of wastewater pollutants using multivariate analyses.

    PubMed

    Kumari, Menka; Tripathi, B D

    2014-07-01

    A faster and cost-effective methodology has been developed to estimate the spatial and seasonal variations in wastewater quality and apportion the influencing sources through multivariate statistical techniques, cluster analysis and principal component analysis (PCA). Partially treated or untreated wastewater is released into the river from various industrial and domestic sources, which poses a serious threat to human health. Wastewater samples were collected from five stations along the river bank. PCA performed on overall wastewater samples revealed that in present study all the five sampling stations were influenced by sewage and industrial effluents mixed together. However, the pollutant levels were significantly different in the three groups of wastewater samples, which were confirmed by univariate analysis of principal component (PC) scores. Based on wastewater similarities, cluster analysis identified three groups (central, upstream and downstream) of sampling stations, which further confirmed univariate analysis of PCs scores. Spatial variations in wastewater quality reveled that the highest pollutant concentration was noted for group 1 and lowest for group 2. Seasonal variations in the wastewater quality revealed that highest values of pollutants were observed in low flow and lowest in high flow. Results of the present study obtained through multivariate analyses may be used to classify wastewater and identify the influencing sources of pollutants. The present study may be useful in reducing 11 % of the cost in future investigations. Thus, in future quality estimation of the representative wastewater samples would be faster as well as cost-effective approach. PMID:24599147

  15. Source apportionment studies on particulate matter in Beijing/China

    NASA Astrophysics Data System (ADS)

    Suppan, P.; Shen, R.; Shao, L.; Schrader, S.; Schäfer, K.; Norra, S.; Vogel, B.; Cen, K.; Wang, Y.

    2013-05-01

    More than 15 million people in the greater area of Beijing are still suffering from severe air pollution levels caused by sources within the city itself but also from external impacts like severe dust storms and long range advection from the southern and central part of China. Within this context particulate matter (PM) is the major air pollutant in the greater area of Beijing (Garland et al., 2009). PM did not serve only as lead substance for air quality levels and therefore for adverse health impact effects but also for a strong influence on the climate system by changing e.g. the radiative balance. Investigations on emission reductions during the Olympic Summer Games in 2008 have caused a strong reduction on coarser particles (PM10) but not on smaller particles (PM2.5). In order to discriminate the composition of the particulate matter levels, the different behavior of coarser and smaller particles investigations on source attribution, particle characteristics and external impacts on the PM levels of the city of Beijing by measurements and modeling are performed: a) Examples of long term measurements of PM2.5 filter sampling in 2010/2011 with the objectives of detailed chemical (source attribution, carbon fraction, organic speciation and inorganic composition) and isotopic analyses as well as toxicological assessment in cooperation with several institutions (Karlsruhe Institute of Technology (IfGG/IMG), Helmholtz Zentrum München (HMGU), University Rostock (UR), Chinese University of Mining and Technology Beijing, CUMTB) will be discussed. b) The impact of dust storm events on the overall pollution level of particulate matter in the greater area of Beijing is being assessed by the online coupled comprehensive model system COSMO-ART. First results of the dust storm modeling in northern China (2011, April 30th) demonstrates very well the general behavior of the meteorological parameters temperature and humidity as well as a good agreement between modeled and

  16. Source apportionment of atmospheric PAHs in the Western Balkans by natural abundance radiocarbon analysis

    SciTech Connect

    Zdenek Zencak; Jana Klanova; Ivan Holoubek; Oerjan Gustafsson

    2007-06-01

    Progress in source apportionment of priority combustion-derived atmospheric pollutants can be made by an inverse approach to inventory emissions, namely, receptor-based compound class-specific radiocarbon analysis (CCSRA) of target pollutants. In the present study, CCSRA of the combustion-derived polycyclic aromatic hydrocarbons (PAHs) present in the atmosphere of the countries of the former republic of Yugoslavia was performed. The carbon stable isotope composition ({delta}{sup 13}C) of PAHs varied between -27.68 and -27.19{per_thousand}, whereas {Delta}{sup 14}C values ranged from -568{per_thousand} for PAHs sampled in Kosovo to -288{per_thousand} for PAHs sampled in the Sarajevo area. The application of an isotopic mass balance model to these {Delta}{sup 14}C data revealed a significant contribution (35-65%) from the combustion of non-fossil material to the atmospheric PAH pollution, even in urban and industrialized areas. Furthermore, consistency was observed between the isotopic composition of PAHs obtained by high-volume sampling and those collected by passive sampling. This encourages the use of passive samplers for CCSRA applications. This marks the first time that a CCSRA investigation could be executed on a geographically wide scale, providing a quantitative field-based source apportionment, which points out that also non-fossil combustion processes should be targeted for remedial action. 36 refs., 1 fig., 3 tabs.

  17. Volatility of organic molecular markers used for source apportionment analysis: measurements and implications for atmospheric lifetime.

    PubMed

    May, Andrew A; Saleh, Rawad; Hennigan, Christopher J; Donahue, Neil M; Robinson, Allen L

    2012-11-20

    Molecular markers are organic species used to define fingerprints for source apportionment of ambient fine particulate matter. Traditionally, these markers have been assumed to be stable in the atmosphere. This work investigates the gas-particle partitioning of eight organic species used as molecular markers in receptor models for biomass burning (levoglucosan), motor vehicles (5α-cholestane, n-hexacosane, n-triacontane, 1,2-benz[a]anthracene, coronene), and meat cooking (cholesterol, oleic acid). Experiments were conducted using a thermodenuder to measure the evaporation of single component particles. The data were analyzed using the integrated volume method to determine saturation concentrations and enthalpies of vaporization for each compound. The results indicate that appreciable quantities (>10%) of most of these markers exist in the gas phase under typical atmospheric conditions. Therefore, these species should be considered semivolatile. Predictions from a chemical kinetics model indicate that gas-particle partitioning has important effects on the atmospheric lifetime of these species. The atmospheric decay of semivolatile compounds proceeds much more rapidly than nonvolatile compounds because gas-phase oxidation induces evaporation of particle-phase material. Therefore, both gas-particle partitioning and chemical reactions need to be accounted for when semivolatile molecular markers are used for source apportionment studies. PMID:23013599

  18. Contamination characteristics and source apportionment of trace metals in soils around Miyun Reservoir.

    PubMed

    Chen, Haiyang; Teng, Yanguo; Chen, Ruihui; Li, Jiao; Wang, Jinsheng

    2016-08-01

    Due to their toxicity and bioaccumulation, trace metals in soils can result in a wide range of toxic effects on animals, plants, microbes, and even humans. Recognizing the contamination characteristics of soil metals and especially apportioning their potential sources are the necessary preconditions for pollution prevention and control. Over the past decades, several receptor models have been developed for source apportionment. Among them, positive matrix factorization (PMF) has gained popularity and was recommended by the US Environmental Protection Agency as a general modeling tool. In this study, an extended chemometrics model, multivariate curve resolution-alternating least squares based on maximum likelihood principal component analysis (MCR-ALS/MLPCA), was proposed for source apportionment of soil metals and applied to identify the potential sources of trace metals in soils around Miyun Reservoir. Similar to PMF, the MCR-ALS/MLPCA model can incorporate measurement error information and non-negativity constraints in its calculation procedures. Model validation with synthetic dataset suggested that the MCR-ALS/MLPCA could extract acceptable recovered source profiles even considering relatively larger error levels. When applying to identify the sources of trace metals in soils around Miyun Reservoir, the MCR-ALS/MLPCA model obtained the highly similar profiles with PMF. On the other hand, the assessment results of contamination status showed that the soils around reservoir were polluted by trace metals in slightly moderate degree but potentially posed acceptable risks to the public. Mining activities, fertilizers and agrochemicals, and atmospheric deposition were identified as the potential anthropogenic sources with contributions of 24.8, 14.6, and 13.3 %, respectively. In order to protect the drinking water source of Beijing, special attention should be paid to the metal inputs to soils from mining and agricultural activities. PMID:27107989

  19. Application of disperion models for layered haze source apportionment

    SciTech Connect

    Latimer, D.A. )

    1988-01-01

    The phenomenon of layered haze, forms of visibility impairment, is of concern to the National Park Service, presumably because it may adversely affect the visual experience of visitors to national parks and wilderness areas.Because layered haze has been observed principally in the winter at locations such as Bryce Canyon and Mesa Verde national parks, which are adjacent to large , coal-fired power plants, it ahs been speculated that these plants may be large contributors to such haze. Although special studies have been carried out during the past two winters (1985-6 and 1986-87) specifically to study layered haze near Bryce Canyon, conclusive results as to the cause of and principal source contributors to wintertime layered haze have not yet been obtained. A critical question that remains to be answered regarding this wintertime layered haze is the relative contribution of the local power plant (Navajo) and other emissions from the populated areas (e.g. from coal- and wood-fired space heaters in the town of Page and on the Navajo and Hopi Indian Reservations) compared to other more distant sources located throughout the Southwest. The authors discuss two different models designed in an attempt to place bounds in the relative impact of the Navajo Generating Station, based on different assumptions, to address the relative impact of the Navajo plant on winter layered haze. These calculations can only be considered bounding calculations at this time because of the significant uncertainties in atmospheric flow and dispersion conditions and plume chemistry; however, they may be useful in interpreting the results of on-going studies if the layered haze phenomenon.

  20. Fine Particulate Pollution and Source Apportionment in the Urban Centers for Africa, Asia and Latin America

    NASA Astrophysics Data System (ADS)

    Guttikunda, S. K.; Johnson, T. M.; Procee, P.

    2004-12-01

    Fossil fuel combustion for domestic cooking and heating, power generation, industrial processes, and motor vehicles are the primary sources of air pollution in the developing country cities. Over the past twenty years, major advances have been made in understanding the social and economic consequences of air pollution. In both industrialized and developing countries, it has been shown that air pollution from energy combustion has detrimental impacts on human health and the environment. Lack of information on the sectoral contributions to air pollution - especially fine particulates, is one of the typical constraints for an effective integrated urban air quality management program. Without such information, it is difficult, if not impossible, for decision makers to provide policy advice and make informed investment decisions related to air quality improvements in developing countries. This also raises the need for low-cost ways of determining the principal sources of fine PM for a proper planning and decision making. The project objective is to develop and verify a methodology to assess and monitor the sources of PM, using a combination of ground-based monitoring and source apportionment techniques. This presentation will focus on four general tasks: (1) Review of the science and current activities in the combined use of monitoring data and modeling for better understanding of PM pollution. (2) Review of recent advances in atmospheric source apportionment techniques (e.g., principal component analysis, organic markers, source-receptor modeling techniques). (3) Develop a general methodology to use integrated top-down and bottom-up datasets. (4) Review of a series of current case studies from Africa, Asia and Latin America and the methodologies applied to assess the air pollution and its sources.

  1. A novel approach for apportionment between primary and secondary sources of airborne nitrated polycyclic aromatic hydrocarbons (NPAHs)

    NASA Astrophysics Data System (ADS)

    Lin, Yan; Qiu, Xinghua; Ma, Yiqiu; Wang, Junxia; Wu, Yusheng; Zeng, Limin; Hu, Min; Zhu, Tong; Zhu, Yifang

    2016-08-01

    Nitrated polycyclic aromatic hydrocarbons (NPAHs) are strong environmental mutagens and carcinogens originating from both primary emissions and secondary reactions in the atmosphere. The sources and the toxicity of different NPAH species could vary greatly; therefore a specie-specific source apportionment is essential to evaluate their health risks and to formulate controlling regulations. However, few studies have reported source apportionment of NPAHs species to date. In this study, we developed an easy-to-perform method for the apportionment of primary versus secondary sources of airborne NPAHs based on the relationship between NPAHs and NO2. After log-transformation of both NPAHs and NO2 concentrations, a slope of β between these two variables was obtained by the linear regression. When β is significantly smaller than 1, it indicates primary emissions while β significantly greater than 1 suggests secondary formation. We have validated this method with data previously collected in Beijing. A good correlation, with R value of 0.57, was observed between results produced by this new method and by Positive Matrix Factorization (PMF). The correlation could be further improved (R = 0.71) if the gas/particle partition of NPAHs is taken into consideration. This developed method enables the source apportionment for individual NPAHs species and could be used to validate the results of other receptor models.

  2. Source apportionment and source/sink relationships of PAHs in the coastal atmosphere of Chicago and Lake Michigan

    NASA Astrophysics Data System (ADS)

    Simcik, Matt F.; Eisenreich, Steven J.; Lioy, Paul J.

    Multivariate statistical techniques were used to investigate source apportionment and source/sink relationships for polycyclic aromatic hydrocarbons (PAHs) in the urban and adjacent coastal atmosphere of Chicago/Lake Michigan in 1994-1995. The PAH signatures for the atmospheric particle phase, surface water particle phase and sediments indicate that atmospheric deposition is the major source of PAHs to the sediments and water column particulate phase of Lake Michigan. The PAH signature for the atmospheric gas phase and water dissolved phase indicate an intimate linkage between the lake and its overlying atmosphere. A modified factor analysis-multiple regression model was successfully applied to the source apportionment of atmospheric PAHs (gas+particle). Coal combustion accounted for 48±5% of the ΣPAH concentration in both the urban and adjacent coastal atmosphere, natural gas combustion accounted for 26±2%, coke ovens accounted for 14±3%, and vehicle emissions (gas+diesel) accounted for 9±4%. Each is an identified source category for the region. These results are consistent with the mix of fossil fuel combustion sources and ratios of indicator PAHs.

  3. The Analysis of PM2.5 Source Apportionment Technique's Competitiveness in China

    NASA Astrophysics Data System (ADS)

    Qian, K.; Deng, L.; An, Y. B.; Liu, S. Y.; Hao, H. Z.

    Nowadays, people has paid more attention to PM2.5 in various countries of the world. PM2.5 is a kind of particulate matter whose diameter less than 2.5μm, with great damage to environment and public's health. The origin of source apportionment technique is studies of atmospheric particulate matter, it uses two mathematical models, one of them is diffusion model which study the source of pollution, and another one called receptor model which study the pollution of area. In my study, I will analyze the competitiveness of similar technology in various countries by using microscope to analyze shape characteristic, Enrichment Factor Method (EF), Factor Analyze Method (FA), EPA-CMB8.2 Model, combining with the consequence of Improved-source-analysis Technology and Orthogonal matrix decomposition Model.

  4. Source apportionment of ambient VOCS in Mumbai city

    NASA Astrophysics Data System (ADS)

    Srivastava, Anjali

    Air pollution kills almost half a million Asians every year. Most of this pollution is emitted from buses, trucks, motorcycles and other forms of transport. As Asia's cities continue to expand, the rising number of vehicles has resulted in even greater pollution. Amongst the measures available to control, vehicular emission was engine modification, catalytic converters and fuel modifications. Some of these have led to emissions of some hazardous air pollutants (HAP) like volatile organic compounds (VOCs). VOC emission is an area needing attention in air quality management. This paper discusses a study on VOC concentration at major sources like traffic junction, residential area, commercial areas, industrial areas and petrol pumps in Mumbai city. CMB8 Model has been used to apportion VOCs in Mumbai city. It was observed that evaporative emissions dominate in Mumbai. In order to control VOCs in air the management strategy should thus focus on cost effective vapor recovery systems at refueling stations and in vehicles. Effective inspection and maintenance programme can reduce evaporative and exhaust VOC emissions. Modifying certain fuel parameters, like reducing benzene content in petrol will as well reduce VOC content in air. The benzene content in petrol was 3% in the year 2001 in Mumbai. Adulteration also results in high levels of VOCs in air.

  5. Measurement, time series analysis and source apportionment of inorganic and organic speciated PM(2.5) air pollution in Denver

    NASA Astrophysics Data System (ADS)

    Dutton, Steven James

    Particulate air pollution has demonstrated significant health effects ranging from worsening of asthma to increased rates of respiratory and cardiopulmonary mortality. These results have prompted the US-EPA to include particulate matter (PM) as one of the six criteria air pollutants regulated under the Clean Air Act. The diverse chemical make-up and physical characteristics of PM make it a challenging pollutant to characterize and regulate. Particulate matter less than 2.5 microns in diameter (PM2.5) has the ability to travel deep into the lungs and therefore has been linked with some of the more significant health effects. The toxicity of any given particle is likely dependent on its chemical composition. The goal of this project has been to chemically characterize a long time series of PM 2.5 measurements collected at a receptor site in Denver to a level of detail that has not been done before on this size data set. This has involved characterization of inorganic ions using ion chromatography, total elemental and organic carbon using thermal optical transmission, and organic molecular marker species using gas chromatography-mass spectrometry. Methods have been developed to allow for daily measurement and speciation for these compounds over a six year period. Measurement methods, novel approaches to uncertainty estimation, time series analysis, spectral and pattern analyses and source apportionment using two multivariate factor analysis models are presented. Analysis results reveal several natural and anthropogenic sources contributing to PM2.5 in Denver. The most distinguishable sources are motor vehicles and biomass combustion. This information will be used in a health effect analysis as part of a larger study called the Denver Aerosol Sources and Health (DASH) study. Such results will inform regulatory decisions and may help create a better understanding of the underlying mechanisms for the observed adverse health effects associated with PM2.5.

  6. SOURCE APPORTIONMENT OF EXPOSURES TO VOLATILE ORGANIC COMPOUNDS: II. APPLICATION OF RECEPTOR MODELS TO TEAM STUDY DATA. (R826788)

    EPA Science Inventory

    Four receptor-oriented source apportionment models were applied to personal exposure measurements for toxic volatile organic compounds (VOCs). The measurements are from the total exposure assessment methodology studies conducted from 1980 to 1984 in New Jersey (NJ) and Califor...

  7. SOURCE APPORTIONMENT OF PM 2.5 AND CARBON IN SEATTLE USING CHEMICAL MASS BALANCE AND POSITIVE MATRIX FACTORIZATION

    EPA Science Inventory

    Three years of PM2.5 speciated data were collected and chemically analyzed using the IMPROVE protocol at the Beacon Hill site in Seattle. The data were analyzed by the Chemical Mass Balance Version 8 (CMB8) and Positive Matrix Factorization (PMF) source apportionment models. T...

  8. Source apportionment and health effect of NOx over the Pearl River Delta region in southern China.

    PubMed

    Lu, Xingcheng; Yao, Teng; Li, Ying; Fung, Jimmy C H; Lau, Alexis K H

    2016-05-01

    As one of the most notorious atmospheric pollutants, NOx not only promotes the formation of ozone but also has adverse health effects on humans. It is therefore of great importance to study the sources of NOx and its effects on human health. The Comprehensive Air Quality Model (CAMx) modeling system and ozone source apportionment technology (OSAT) were used to study the contribution of NOx from different emission sources over southern China. The results indicate that heavy duty diesel vehicles (HDDVs) and industrial point sources are the two major local NOx sources, accounting for 30.8% and 18.5% of local NOx sources, respectively. In Hong Kong, marine emissions contributed around 43.4% of local NOx in 2011. Regional transport is another important source of this pollutant, especially in February and November, and it can contribute over 30% of ambient NOx on average. Power plant point emission is an significant regional source in Zhuhai, Zhongshan and Foshan. The total emission sources are estimated to cause 2119 (0-4405) respiratory deaths and 991 (0-2281) lung cancer deaths due to long-term exposure to NOx in the Pearl River Delta region. Our results suggest that local governments should combine their efforts and vigorously promote further reduction of NOx emissions, especially for those sources that make a substantial contribution to NOx emissions and affect human health: HDDV, LDGV, industrial point sources and marine sources. PMID:26845361

  9. [Source apportionment of soil heavy metals in Jiapigou goldmine based on the UNMIX model].

    PubMed

    Ai, Jian-chao; Wang, Ning; Yang, Jing

    2014-09-01

    The paper determines 16 kinds of metal elements' concentration in soil samples which collected in Jipigou goldmine upper the Songhua River. The UNMIX Model which was recommended by US EPA to get the source apportionment results was applied in this study, Cd, Hg, Pb and Ag concentration contour maps were generated by using Kriging interpolation method to verify the results. The main conclusions of this study are: (1)the concentrations of Cd, Hg, Pb and Ag exceeded Jilin Province soil background values and enriched obviously in soil samples; (2)using the UNMIX Model resolved four pollution sources: source 1 represents human activities of transportation, ore mining and garbage, and the source 1's contribution is 39. 1% ; Source 2 represents the contribution of the weathering of rocks and biological effects, and the source 2's contribution is 13. 87% ; Source 3 is a comprehensive source of soil parent material and chemical fertilizer, and the source 3's contribution is 23. 93% ; Source 4 represents iron ore mining and transportation sources, and the source 4's contribution is 22. 89%. (3)the UNMIX Model results are in accordance with the survey of local land-use types, human activities and Cd, Hg and Pb content distributions. PMID:25518676

  10. Source apportionment of trace metals in river sediments: A comparison of three methods.

    PubMed

    Chen, Haiyang; Teng, Yanguo; Li, Jiao; Wu, Jin; Wang, Jinsheng

    2016-04-01

    Increasing trace metal pollution in river sediment poses a significant threat to watershed ecosystem health. Identifying potential sources of sediment metals and apportioning their contributions are of key importance for proposing prevention and control strategies of river pollution. In this study, three advanced multivariate receptor models, factor analysis with nonnegative constraints (FA-NNC), positive matrix factorization (PMF), and multivariate curve resolution weighted-alternating least-squares (MCR-WALS), were comparatively employed for source apportionment of trace metals in river sediments and applied to the Le'an River, a main tributary of Poyang Lake which is the largest freshwater lake in China. The pollution assessment with contamination factor and geoaccumulation index suggested that the river sediments in Le'an River were contaminated severely by trace metals due to human activities. With the three apportionment tools, similar source profiles of trace metals in sediments were extracted. Especially, the MCR-WALS and PMF models produced essentially the same results. Comparatively speaking, the weighted schemes might give better solutions than the unweighted FA-NNC because the uncertainty information of environmental data was considered by PMF and MCR-WALS. Anthropogenic sources were apportioned as the most important pollution sources influencing the sediment metals in Le'an River with contributions of about 90%. Among them, copper tailings occupied the largest contribution (38.4-42.2%), followed by mining wastewater (29.0-33.5%), and agricultural activities (18.2-18.7%). To protect the ecosystem of Le'an River and Poyang Lake, special attention should be paid to the discharges of mining wastewater and the leachates of copper tailing ponds in that region. PMID:26736053

  11. Characterization and source apportionment of fine particulate sources at Rijeka, Croatia from 2013 to 2015

    NASA Astrophysics Data System (ADS)

    Ivošević, Tatjana; Stelcer, Eduard; Orlić, Ivica; Bogdanović Radović, Iva; Cohen, David

    2016-03-01

    PM2.5 daily aerosol samples were collected in Rijeka, Croatia during period from 6th August 2013 to 29th January 2015. In total, 259 samples were collected on Teflon filters and analyzed by PIXE and PIGE techniques to give information on 21 elements from Na to Pb. Additionally, black carbon was determined with the Laser Integrated Plate Method. Results were statistically evaluated using Positive Matrix Factorization (PMF). Eight major pollution sources: auto, smoke, secondary sulfates, heavy oil combustion, sea spray, road dust, industry iron and soil dust were identified together with their relative contributions in total PM2.5 pollution.

  12. Source identification and apportionment of halogenated compounds observed at a remote site in East Asia.

    PubMed

    Li, Shanlan; Kim, Jooil; Park, Sunyoung; Kim, Seung-Kyu; Park, Mi-Kyung; Mühle, Jens; Lee, Gangwoong; Lee, Meehye; Jo, Chun Ok; Kim, Kyung-Ryul

    2014-01-01

    The sources of halogenated compounds in East Asia associated with stratospheric ozone depletion and climate change are relatively poorly understood. High-precision in situ measurements of 18 halogenated compounds and carbonyl sulfide (COS) made at Gosan, Jeju Island, Korea, from November 2007 to December 2011 were analyzed by a positive matrix factorization (PMF). Seven major industrial sources were identified from the enhanced concentrations of halogenated compounds observed at Gosan and corresponding concentration-based source contributions were also suggested: primary aluminum production explaining 37% of total concentration enhancements, solvent usage of which source apportionment is 25%, fugitive emissions from HCFC/HFC production with 11%, refrigerant replacements (9%), semiconductor/electronics industry (9%), foam blowing agents (6%), and fumigation (3%). Statistical trajectory analysis was applied to specify the potential emission regions for seven sources using back trajectories. Primary aluminum production, solvent usage and fugitive emission sources were mainly contributed by China. Semiconductor/electronics sources were dominantly located in Korea. Refrigerant replacement, fumigation and foam blowing agent sources were spread throughout East Asian countries. The specified potential source regions are consistent with country-based consumptions and emission patterns, verifying the PMF analysis results. The industry-based emission sources of halogenated compounds identified in this study help improve our understanding of the East Asian countries' industrial contributions to halogenated compound emissions. PMID:24298975

  13. Ensemble-Based Source Apportionment of Fine Particulate Matter and Emergency Department Visits for Pediatric Asthma

    PubMed Central

    Gass, Katherine; Balachandran, Sivaraman; Chang, Howard H.; Russell, Armistead G.; Strickland, Matthew J.

    2015-01-01

    Epidemiologic studies utilizing source apportionment (SA) of fine particulate matter have shown that particles from certain sources might be more detrimental to health than others; however, it is difficult to quantify the uncertainty associated with a given SA approach. In the present study, we examined associations between source contributions of fine particulate matter and emergency department visits for pediatric asthma in Atlanta, Georgia (2002–2010) using a novel ensemble-based SA technique. Six daily source contributions from 4 SA approaches were combined into an ensemble source contribution. To better account for exposure uncertainty, 10 source profiles were sampled from their posterior distributions, resulting in 10 time series with daily SA concentrations. For each of these time series, Poisson generalized linear models with varying lag structures were used to estimate the health associations for the 6 sources. The rate ratios for the source-specific health associations from the 10 imputed source contribution time series were combined, resulting in health associations with inflated confidence intervals to better account for exposure uncertainty. Adverse associations with pediatric asthma were observed for 8-day exposure to particles generated from diesel-fueled vehicles (rate ratio = 1.06, 95% confidence interval: 1.01, 1.10) and gasoline-fueled vehicles (rate ratio = 1.10, 95% confidence interval: 1.04, 1.17). PMID:25776011

  14. PM₁₀ and PM₂.₅ sources at an insular location in the western Mediterranean by using source apportionment techniques.

    PubMed

    Pey, Jorge; Alastuey, Andrés; Querol, Xavier

    2013-07-01

    PM₁₀ and PM₂.₅ chemical composition has been determined at a suburban insular site in the Balearic Islands (Spain) during almost one and a half year. As a result, 200 samples with more than 50 chemical parameters analyzed have been obtained. The whole database has been analyzed by two receptor modelling techniques (Principal Component Analysis and Positive Matrix Factorisation) in order to identify the main PM sources. After that, regression analyses with respect to the PM mass concentrations were conducted to quantify the daily contributions of each source. Four common sources were identified by both receptor models: secondary nitrate coupled with vehicular emissions, secondary sulphate influenced by fuel-oil combustion, aged marine aerosols and mineral dust. In addition, PCA isolated harbour emissions and a mixed anthropogenic factor containing industrial emissions; whereas PMF isolated an additional mineral factor interpreted as road dust+harbour emissions, and a vehicular abrasion products factor. The use of both methodologies appeared complementary. Nevertheless, PMF sources by themselves were better differentiated. Besides these receptor models, a specific methodology to quantify African dust was also applied. The combination of these three source apportionment tools allowed the identification of 8 sources, being 4 of them mineral (African, regional, urban and harbour dusts). As a summary, 29% of PM₁₀ was attributed to natural sources (African dust, regional dust and sea spray), whereas the proportion diminished to 11% in PM₂.₅. Furthermore, the secondary sulphate source, which accounted for about 22 and 32% of PM₁₀ and PM₂.₅, is strongly linked to the aged polluted air masses residing over the western Mediterranean in the warm period. PMID:23611951

  15. A stable isotope model for combined source apportionment and degradation quantification of environmental pollutants

    NASA Astrophysics Data System (ADS)

    Lutz, Stefanie; Van Breukelen, Boris

    2014-05-01

    Natural attenuation can represent a complementary or alternative approach to engineered remediation of polluted sites. In this context, compound specific stable isotope analysis (CSIA) has proven a useful tool, as it can provide evidence of natural attenuation and assess the extent of in-situ degradation based on changes in isotope ratios of pollutants. Moreover, CSIA can allow for source identification and apportionment, which might help to identify major emission sources in complex contamination scenarios. However, degradation and mixing processes in aquifers can lead to changes in isotopic compositions, such that their simultaneous occurrence might complicate combined source apportionment (SA) and assessment of the extent of degradation (ED). We developed a mathematical model (stable isotope sources and sinks model; SISS model) based on the linear stable isotope mixing model and the Rayleigh equation that allows for simultaneous SA and quantification of the ED in a scenario of two emission sources and degradation via one reaction pathway. It was shown that the SISS model with CSIA of at least two elements contained in the pollutant (e.g., C and H in benzene) allows for unequivocal SA even in the presence of degradation-induced isotope fractionation. In addition, the model enables precise quantification of the ED provided degradation follows instantaneous mixing of two sources. If mixing occurs after two sources have degraded separately, the model can still yield a conservative estimate of the overall extent of degradation. The SISS model was validated against virtual data from a two-dimensional reactive transport model. The model results for SA and ED were in good agreement with the simulation results. The application of the SISS model to field data of benzene contamination was, however, challenged by large uncertainties in measured isotope data. Nonetheless, the use of the SISS model provided a better insight into the interplay of mixing and degradation

  16. Investigating types and sources of organic aerosol in Rocky Mountain National Park using aerosol mass spectrometry

    NASA Astrophysics Data System (ADS)

    Schurman, M. I.; Lee, T.; Sun, Y.; Schichtel, B. A.; Kreidenweis, S. M.; Collett, J. L., Jr.

    2015-01-01

    The environmental impacts of atmospheric particles are highlighted in remote areas where visibility and ecosystem health can be degraded by even relatively low particle concentrations. Submicron particle size, composition, and source apportionment were explored at Rocky Mountain National Park using a High-Resolution Time-of-Flight Aerosol Mass Spectrometer. This summer campaign found low average, but variable, particulate mass (PM) concentrations (max = 93.1 μg m-3, avg. = 5.13 ± 2.72 μg m-3) of which 75.2 ± 11.1% is organic. Low-volatility oxidized organic aerosol (LV-OOA, 39.3% of PM1 on average) identified using Positive Matrix Factorization appears to be mixed with ammonium sulfate (3.9% and 16.6% of mass, respectively), while semi-volatile OOA (27.6%) is correlated with ammonium nitrate (nitrate: 4.3%); concentrations of these mixtures are enhanced with upslope (SE) surface winds from the densely populated Front Range area, indicating the importance of transport. A local biomass burning organic aerosol (BBOA, 8.4%) source is suggested by mass spectral cellulose combustion markers (m/z 60 and 73) limited to brief, high-concentration, polydisperse events (suggesting fresh combustion), a diurnal maximum at 22:00 local standard time when campfires were set at adjacent summer camps, and association with surface winds consistent with local campfire locations. The particle characteristics determined here represent typical summertime conditions at the Rocky Mountain site based on comparison to ~10 years of meteorological, particle composition, and fire data.

  17. Investigating types and sources of organic aerosol in Rocky Mountain National Park using aerosol mass spectrometry

    NASA Astrophysics Data System (ADS)

    Schurman, M. I.; Lee, T.; Sun, Y.; Schichtel, B. A.; Kreidenweis, S. M.; Collett, J. L., Jr.

    2014-07-01

    The environmental impacts of atmospheric particles are highlighted in remote areas where visibility and ecosystem health can be degraded by even relatively low particle concentrations. Submicron particle size, composition, and source apportionment were explored at Rocky Mountain National Park using a High-Resolution Time-of-Flight Aerosol Mass Spectrometer. This summer campaign found low average, but variable, particulate mass (PM) concentrations (max = 93.1 μg m-3, avg. = 5.13 ± 2.72 μg m-3) of which 75.2 ± 11.1% is organic. Low-volatility oxidized organic aerosol (LV-OOA, 39.3% of PM1 on average) identified using Positive Matrix Factorization appears to be mixed with ammonium sulfate (3.9 and 16.6% of mass, respectively), while semi-volatile OOA (27.6%) is correlated with ammonium nitrate (nitrate: 4.3%); concentrations of these mixtures are enhanced with upslope (SE) surface winds from the densely populated Front Range area, indicating the importance of transport. A local biomass burning organic aerosol (BBOA, 8.4%) source is suggested by mass spectral cellulose combustion markers (m/zs 60 and 73) limited to brief, high-concentration, polydisperse events (suggesting fresh combustion), a diurnal maximum at 22:00 local standard time (LST) when campfires were set at adjacent summer camps, and association with surface winds consistent with local campfire locations. The particle characteristics determined here represent typical summertime conditions at the Rocky Mountain site based on comparison to ∼10 years of meteorological, particle composition, and fire data.

  18. Monitoring and source apportionment of particulate matter near a large phosphorus production facility.

    PubMed

    Willis, R D; Ellenson, W D; Conner, T L

    2001-08-01

    A source apportionment study was conducted to identify sources within a large elemental phosphorus plant that contribute to exceedances of the National Ambient Air Quality Standards (NAAQS) for 24-hr PM10. Ambient data were collected at three monitoring sites from October 1996 through July 1999, and included the following: 24-hr PM10 mass, 24-hr PM2.5 and PM10-2.5 mass and chemistry, continuous PM10 and PM2.5 mass, continuous meteorological data, and wind-direction-resolved PM2.5 and PM10 mass and chemistry. Ambient-based receptor modeling and wind-directional analysis were employed to help identify major sources or source locations and source contributions. Fine-fraction phosphate was the dominant species observed during PM10 exceedances, though in general, resuspended coarse dusts from raw and processed materials at the plant were also needed to create an exceedance. Major sources that were identified included the calciners, the CO flares, process-related dust, and electric-arc furnace operations. PMID:11518289

  19. Overview of receptor-based source apportionment studies for speciated atmospheric mercury

    NASA Astrophysics Data System (ADS)

    Cheng, I.; Xu, X.; Zhang, L.

    2015-02-01

    Receptor-based source apportionment studies of speciated atmospheric mercury are not only concerned with source contributions, but also the influence of transport, transformation, and deposition processes on speciated atmospheric mercury concentrations at receptor locations. Previous studies applied multivariate receptor models including Principal Components Analysis and Positive Matrix Factorization, and back trajectory receptor models including Potential Source Contribution Function, Gridded Frequency Distributions, and Concentration-back trajectory models. Anthropogenic combustion sources, crustal/soil dust, and chemical and physical processes, such as gaseous elemental mercury (GEM) oxidation reactions, boundary layer mixing, and GEM flux from surfaces, were inferred from the multivariate studies, which were predominantly conducted at receptor sites in Canada and the US. Back trajectory receptor models revealed potential impacts of large industrial areas such as the Ohio River Valley in the US and throughout China, metal smelters, mercury evasion from the ocean and Great Lakes, and free troposphere transport on receptor measurements. Input data and model parameters specific to atmospheric mercury receptor models are summarized and model strengths and weaknesses are also discussed. One area of improvement that applies to all receptor models is the greater focus on evaluating the accuracy of receptor models at identifying potential speciated atmospheric mercury sources, source locations, and chemical and physical processes in the atmosphere.

  20. Quantitative identification and source apportionment of anthropogenic heavy metals in marine sediment of Hong Kong

    NASA Astrophysics Data System (ADS)

    Zhou, Feng; Guo, Huaicheng; Liu, Lei

    2007-10-01

    Based on ten heavy metals collected twice annually at 59 sites from 1998 to 2004, enrichment factors (EFs), principal component analysis (PCA) and multivariate linear regression of absolute principal component scores (MLR-APCS) were used in identification and source apportionment of the anthropogenic heavy metals in marine sediment. EFs with Fe as a normalizer and local background as reference values was properly tested and suitable in Hong Kong, and Zn, Ni, Pb, Cu, Cd, Hg and Cr mainly originated from anthropogenic sources, while Al, Mn and Fe were derived from rocks weathering. Rotated PCA and GIS mapping further identified two types of anthropogenic sources and their impacted regions: (1) electronic industrial pollution, riparian runoff and vehicle exhaust impacted the entire Victoria Harbour, inner Tolo Harbour, Eastern Buffer, inner Deep Bay and Cheung Chau; and (2) discharges from textile factories and paint, influenced Tsuen Wan Bay and Kwun Tong typhoon shelter and Rambler Channel. In addition, MLR-APCS was successfully introduced to quantitatively determine the source contributions with uncertainties almost less than 8%: the first anthropogenic sources were responsible for 50.0, 45.1, 86.6, 78.9 and 87.5% of the Zn, Pb, Cu, Cd and Hg, respectively, whereas 49.9% of the Ni and 58.4% of the Cr came from the second anthropogenic sources.

  1. Evaluation of organic markers for chemical mass balance source apportionment at the Fresno Supersite

    NASA Astrophysics Data System (ADS)

    Chow, J. C.; Watson, J. G.; Lowenthal, D. H.; Chen, L. W. A.; Zielinska, B.; Mazzoleni, L. R.; Magliano, K. L.

    2007-04-01

    Sources of PM2.5 at the Fresno Supersite during high PM2.5 episodes occurring from 15 December 2000-3 February 2001 were estimated with the Chemical Mass Balance (CMB) receptor model. The ability of source profiles with organic markers to distinguish motor vehicle, residential wood combustion (RWC), and cooking emissions was evaluated with simulated data. Organics improved the distinction between gasoline and diesel vehicle emissions and allowed a more precise estimate of the cooking source contribution. Sensitivity tests using average ambient concentrations showed that the gasoline vehicle contribution was not resolved without organics. Organics were not required to estimate hardwood contributions. The most important RWC marker was the water-soluble potassium ion. The estimated cooking contribution did not depend on cholesterol because its concentrations were below the detection limit in most samples. Winter time source contributions were estimated by applying the CMB model to individual and average sample concentrations. RWC was the largest source, contributing 29-31% of measured PM2.5. Hardwood and softwood combustion accounted for 16-17% and 12-15%, respectively. Secondary ammonium nitrate and motor vehicle emissions accounted for 31-33% and 9-15%, respectively. The gasoline vehicle contribution (3-10%) was comparable to the diesel vehicle contribution (5-6%). The cooking contribution was 5-19% of PM2.5. Fresno source apportionment results were consistent with those estimated in previous studies.

  2. Source apportionment of airborne particulate matter using organic compounds as tracers

    SciTech Connect

    Schauer, J.J.; Rogge, W.F.; Hildemann, L.M.

    1995-12-31

    A chemical mass balance receptor model based on organic compounds has been developed that relates source contributions to airborne fine particle mass concentrations. Source contributions to the concentrations of specific organic compounds are revealed as well. The model is applied to four air quality monitoring sites in Southern California using atmospheric organic compound concentration data and source test data collected specifically for the purpose of testing this model. The contributions of up to nine primary particle source types can be separately identified in ambient samples based on this method, and approximately 85% of the organic fine aerosol is assigned to primary sources on an annual average basis. The model provides information on source contributions to fine mass concentrations, fine organic aerosol concentrations and individual organic compound concentrations. The largest primary source contributors to fine particle mass concentrations in Los Angeles are found to include diesel engine exhaust, paved road dust, gasoline powered vehicle exhaust, plus emissions from food cooking and wood smoke with smaller contributions from tire dust, plant fragments, natural gas combustion aerosol, and cigarette smoke. Once these primary aerosol source contributions are added to the secondary sulfates and nitrates present, virtually all of the annual average fine particle mass at Los Angeles area monitoring sites can be assigned to its source origin.

  3. Chemical characterization and source apportionment of fine and coarse particulate matter in Lahore, Pakistan

    NASA Astrophysics Data System (ADS)

    Stone, Elizabeth; Schauer, James; Quraishi, Tauseef A.; Mahmood, Abid

    2010-03-01

    Lahore, Pakistan is an emerging megacity that is heavily polluted with high levels of particle air pollution. In this study, respirable particulate matter (PM 2.5 and PM 10) were collected every sixth day in Lahore from 12 January 2007 to 19 January 2008. Ambient aerosol was characterized using well-established chemical methods for mass, organic carbon (OC), elemental carbon (EC), ionic species (sulfate, nitrate, chloride, ammonium, sodium, calcium, and potassium), and organic species. The annual average concentration (±one standard deviation) of PM 2.5 was 194 ± 94 μg m -3 and PM 10 was 336 ± 135 μg m -3. Coarse aerosol (PM 10-2.5) was dominated by crustal sources like dust (74 ± 16%, annual average ± one standard deviation), whereas fine particles were dominated by carbonaceous aerosol (organic matter and elemental carbon, 61 ± 17%). Organic tracer species were used to identify sources of PM 2.5 OC and chemical mass balance (CMB) modeling was used to estimate relative source contributions. On an annual basis, non-catalyzed motor vehicles accounted for more than half of primary OC (53 ± 19%). Lesser sources included biomass burning (10 ± 5%) and the combined source of diesel engines and residual fuel oil combustion (6 ± 2%). Secondary organic aerosol (SOA) was an important contributor to ambient OC, particularly during the winter when secondary processing of aerosol species during fog episodes was expected. Coal combustion alone contributed a small percentage of organic aerosol (1.9 ± 0.3%), but showed strong linear correlation with unidentified sources of OC that contributed more significantly (27 ± 16%). Brick kilns, where coal and other low quality fuels are burned together, are suggested as the most probable origins of unapportioned OC. The chemical profiling of emissions from brick kilns and other sources unique to Lahore would contribute to a better understanding of OC sources in this megacity.

  4. Characterization and source apportionment of water pollution in Jinjiang River, China.

    PubMed

    Chen, Haiyang; Teng, Yanguo; Yue, Weifeng; Song, Liuting

    2013-11-01

    Characterizing water quality and identifying potential pollution sources could greatly improve our knowledge about human impacts on the river ecosystem. In this study, fuzzy comprehensive assessment (FCA), pollution index (PI), principal component analysis (PCA), and absolute principal component score-multiple linear regression (APCS-MLR) were combined to obtain a deeper understanding of temporal-spatial characterization and sources of water pollution with a case study of the Jinjiang River, China. Measurement data were obtained with 17 water quality variables from 20 sampling sites in the December 2010 (withered water period) and June 2011 (high flow period). FCA and PI were used to comprehensively estimate the water quality variables and compare temporal-spatial variations, respectively. Rotated PCA and receptor model (APCS-MLR) revealed potential pollution sources and their corresponding contributions. Application results showed that comprehensive application of various multivariate methods were effective for water quality assessment and management. In the withered water period, most sampling sites were assessed as low or moderate pollution with characteristics pollutants of permanganate index and total nitrogen (TN), whereas 90% sites were classified as high pollution in the high flow period with higher TN and total phosphorus. Agricultural non-point sources, industrial wastewater discharge, and domestic sewage were identified as major pollution sources. Apportionment results revealed that most variables were complicatedly influenced by industrial wastewater discharge and agricultural activities in withered water period and primarily dominated by agricultural runoff in high flow period. PMID:23737126

  5. Development of a chemical source apportionment decision support framework for catchment management.

    PubMed

    Comber, Sean D W; Smith, Russell; Daldorph, Peter; Gardner, Michael J; Constantino, Carlos; Ellor, Brian

    2013-09-01

    EU legislation, including the Water Framework Directive, has led to the application of increasingly stringent quality standards for a wide range of chemical contaminants in surface waters. This has raised the question of how to determine and to quantify the sources of such substances so that measures can be taken to address breaches of these quality standards using the polluter pays principle. Contaminants enter surface waters via a number of diffuse and point sources. Decision support tools are required to assess the relative magnitudes of these sources and to estimate the impacts of any programmes of measures. This work describes the development and testing of a modeling framework, the Source Apportionment Geographical Information System (SAGIS). The model uses readily available national data sets to estimate contributions of a number of nutrients (nitrogen and phosphorus), metals (copper, zinc, cadmium, lead, mercury, and nickel) and organic chemicals (a phthalate and a number of polynuclear aromatic hydrocarbons) from multiple sector sources. Such a tool has not previously been available on a national scale for such a wide range of chemicals. It is intended to provide a common platform to assist stakeholders in future catchment management. PMID:23915347

  6. Source apportionment of formaldehyde during TexAQS 2006 using a source-oriented chemical transport model

    NASA Astrophysics Data System (ADS)

    Zhang, Hongliang; Li, Jingyi; Ying, Qi; Guven, Birnur Buzcu; Olaguer, Eduardo P.

    2013-02-01

    In this study, a source-oriented version of the Community Multiscale Air Quality (CMAQ) model was developed and used to quantify the contributions of five major local emission source types in Southeast Texas (vehicles, industry, natural gas combustion, wildfires, biogenic sources), as well as upwind sources, to regional primary and secondary formaldehyde (HCHO) concentrations. Predicted HCHO concentrations agree well with observations at two urban sites (the Moody Tower [MT] site at the University of Houston and the Haden Road #3 [HRM-3] site operated by Texas Commission on Environmental Quality). However, the model underestimates concentrations at an industrial site (Lynchburg Ferry). Throughout most of Southeast Texas, primary HCHO accounts for approximately 20-30% of total HCHO, while the remaining portion is due to secondary HCHO (30-50%) and upwind sources (20-50%). Biogenic sources, natural gas combustion, and vehicles are important sources of primary HCHO in the urban Houston area, respectively, accounting for 10-20%, 10-30%, and 20-60% of total primary HCHO. Biogenic sources, industry, and vehicles are the top three sources of secondary HCHO, respectively, accounting for 30-50%, 10-30%, and 5-15% of overall secondary HCHO. It was also found that over 70% of PAN in the Houston area is due to upwind sources, and only 30% is formed locally. The model-predicted source contributions to HCHO at the MT generally agree with source apportionment results obtained from the Positive Matrix Factorization (PMF) technique.

  7. Size-resolved source apportionment of particulate matter in urban Beijing during haze and non-haze episodes

    NASA Astrophysics Data System (ADS)

    Tian, S. L.; Pan, Y. P.; Wang, Y. S.

    2016-01-01

    Additional size-resolved chemical information is needed before the physicochemical characteristics and sources of airborne particles can be understood; however, this information remains unavailable in most regions of China due to lacking measurement data. In this study, we report observations of various chemical species in size-segregated particle samples that were collected over 1 year in the urban area of Beijing, a megacity that experiences severe haze episodes. In addition to fine particles, high concentrations of coarse particles were measured during the periods of haze. The abundance and chemical compositions of the particles in this study were temporally and spatially variable, with major contributions from organic matter and secondary inorganic aerosols. The contributions of organic matter to the particle mass decreased from 37.9 to 31.2 %, and the total contribution of sulfate, nitrate and ammonium increased from 19.1 to 33.9 % between non-haze and haze days, respectively. Due to heterogeneous reactions and hygroscopic growth, the peak concentrations of the organic carbon, cadmium and sulfate, nitrate, ammonium, chloride and potassium shifted from 0.43 to 0.65 µm on non-haze days to 0.65-1.1 µm on haze days. Although the size distributions of lead and thallium were similar during the observation period, their concentrations increased by a factor of more than 1.5 on haze days compared with non-haze days. We observed that sulfate and ammonium, which have a size range of 0.43-0.65 µm, sulfate and nitrate, which have a size range of 0.65-1.1 µm, calcium, which has a size range of 5.8-9 µm, and the meteorological factors of relative humidity and wind speed were responsible for haze pollution when the visibility was less than 10 km. Source apportionment using Positive Matrix Factorization showed six PM2.1 sources and seven PM2.1-9 common sources: secondary inorganic aerosol (25.1 % for fine particles vs. 9.8 % for coarse particles), coal combustion (17

  8. Ensemble-trained source apportionment of fine particulate matter and method uncertainty analysis

    NASA Astrophysics Data System (ADS)

    Balachandran, Sivaraman; Pachon, Jorge E.; Hu, Yongtao; Lee, Dongho; Mulholland, James A.; Russell, Armistead G.

    2012-12-01

    An ensemble-based approach is applied to better estimate source impacts on fine particulate matter (PM2.5) and quantify uncertainties in various source apportionment (SA) methods. The approach combines source impacts from applications of four individual SA methods: three receptor-based models and one chemical transport model (CTM). Receptor models used are the chemical mass balance methods CMB-LGO (Chemical Mass Balance-Lipschitz global optimizer) and CMB-MM (molecular markers) as well as a factor analytic method, Positive Matrix Factorization (PMF). The CTM used is the Community Multiscale Air Quality (CMAQ) model. New source impact estimates and uncertainties in these estimates are calculated in a two-step process. First, an ensemble average is calculated for each source category using results from applying the four individual SA methods. The root mean square error (RMSE) between each method with respect to the average is calculated for each source category; the RMSE is then taken to be the updated uncertainty for each individual SA method. Second, these new uncertainties are used to re-estimate ensemble source impacts and uncertainties. The approach is applied to data from daily PM2.5 measurements at the Atlanta, GA, Jefferson Street (JST) site in July 2001 and January 2002. The procedure provides updated uncertainties for the individual SA methods that are calculated in a consistent way across methods. Overall, the ensemble has lower relative uncertainties as compared to the individual SA methods. Calculated CMB-LGO uncertainties tend to decrease from initial estimates, while PMF and CMB-MM uncertainties increase. Estimated CMAQ source impact uncertainties are comparable to other SA methods for gasoline vehicles and SOC but are larger than other methods for other sources. In addition to providing improved estimates of source impact uncertainties, the ensemble estimates do not have unrealistic extremes as compared to individual SA methods and avoids zero impact

  9. Source apportionment of traffic emissions of particulate matter using tunnel measurements

    NASA Astrophysics Data System (ADS)

    Lawrence, Samantha; Sokhi, Ranjeet; Ravindra, Khaiwal; Mao, Hongjun; Prain, Hunter Douglas; Bull, Ian D.

    2013-10-01

    This study aims to quantify exhaust/non-exhaust emissions and the uncertainties associated with them by combining innovative motorway tunnel sampling and source apportionment modelling. Analytical techniques ICP-AES and GC-MS were used to identify the metallic and organic composition of PM10, respectively. Good correlation was observed between Fe, Cu, Mn, Ni, Pb and Sb and change in traffic volume. The concentration of polycyclic aromatic hydrocarbons and other organics varies significantly at the entrance and exit site of the tunnel, with fluoranthene, pyrene, benzo[a]pyrene, chrysene and benzothiazole having the highest incremented concentrations. The application of Principal Component Analysis and Multiple Linear Regression Analysis helped to identify the emission sources for 82% of the total PM10 mass inside the tunnel. Identified sources include resuspension (27%), diesel exhaust emissions (21%), petrol exhaust emissions (12%), brake wear emissions (11%) and road surface wear (11%). This study shows that major health related chemical species of PM10 originate from non-exhaust sources, further signifying the need for legislation to reduce these emissions.

  10. Source apportionment of atmospheric PAHs and their toxicity using PMF: Impact of gas/particle partitioning

    NASA Astrophysics Data System (ADS)

    Gao, Bo; Wang, Xin-Ming; Zhao, Xiu-Ying; Ding, Xiang; Fu, Xiao-Xin; Zhang, Yan-Li; He, Quan-Fu; Zhang, Zhou; Liu, Teng-Yu; Huang, Zou-Zhao; Chen, Lai-Guo; Peng, Yan; Guo, Hai

    2015-02-01

    24-h PM2.5 samples were simultaneously collected at six sites in a subtropical city of South China during November-December, 2009. Particle-phase concentrations of polycyclic aromatic hydrocarbons (PAHs) and organic tracers such as hopanes for vehicular emissions (VE), levoglucosan for biomass burning (BB) and picene for coal combustion (CC) were determined. Meanwhile, their gas-phase concentrations were calculated from gas/particle (G/P) partitioning theory using the particle-phase concentrations. The 4 ring PAHs (fluoranthene to chrysene) had lower particle-phase fractions (10%-79%) than other species. Estimated BaPeq and lifetime cancer risk for particle-only (P-only) vs gas + particle (G + P) data sets showed similar values, indicating PAHs with 5-7 rings dominated the carcinogenicity of PAHs. Positive Matrix Factorization (PMF) was applied on both P-only and G + P data sets to estimate the source contributions to PAHs and their toxicity. Three common sources were identified: VE, BB and CC, with CC as the most significant source for both particulate (58%) and total (G + P, 40%) PAHs. While CC exhibited consistent contributions to BaPeq for P-only (66%) vs G + P (62%) solutions, VE and BB contributions were under- and overestimated by 68% and 47%, respectively by the P-only solution, as compared to the G + P solution. The results provide an insight on the impact of G/P partitioning on the source apportionment of PAHs and their toxicity.

  11. Source apportionment and organic compound characterization of ambient ultrafine particulate matter (PM) in the Los Angeles Basin

    NASA Astrophysics Data System (ADS)

    Hasheminassab, Sina; Daher, Nancy; Schauer, James J.; Sioutas, Constantinos

    2013-11-01

    In this study, quasi-UFP (PM0.25, dp < 0.25 μm) were collected for 24 h once per week from April 2008 to March 2009 at 10 different locations in the Los Angeles Basin. Samples were chemically analyzed and organic constituents of PM0.25 were grouped into polycyclic aromatic hydrocarbon (PAHs), hopanes and steranes, n-alkanes, and levoglucosan, with concentration levels ranging from 0.16 to 5.5, 0.09 to 2.2, 9.3 to 48, and 2.2 to 106.2 ng m-3 over all sites and seasons, respectively. A molecular marker-based chemical mass balance (MM-CMB) model was applied to estimate the relative contributions from the following primary sources: mobile sources (combined gasoline and diesel vehicles), wood smoke, natural gas combustion, vegetative detritus, and ship emissions. Secondary organic aerosol (SOA) tracers were not included in the model; however their contributions were estimated from non-biomass burning water soluble organic carbon (WSOCnb) and un-apportioned OC from MM-CMB model (“other OC”). High correlation (R2 = 0.8) between “other OC” and WSOCnb in summer suggests that “other OC” is highly impacted by SOA, however un-apportioned primary sources may contribute to “other OC” as well. Mobile sources were expectedly the major primary contributor to PM0.25, with seasonal average contributions of 31 ± 12% in summer and 57 ± 17% in winter. “Other organic matter” was the second largest contributor to PM0.25 in all seasons, across the basin, with substantially higher contribution during warmer spring and summer seasons (27%), while lowest during cold seasons (13%). Wood smoke was the third major contributor to PM0.25 in winter, whereas its contribution was lowest in summer. As expected, ship emissions displayed the highest contribution at the near-harbor HUD site, and their levels continually decreased as a function of distance from coast. Two other primary sources, vegetative detritus and natural gas combustion, collectively contributed to 1.3 ± 0

  12. Composition and source apportionment of dust fall around a natural lake.

    PubMed

    Latif, Mohd Talib; Ngah, Sofia Aida; Dominick, Doreena; Razak, Intan Suraya; Guo, Xinxin; Srithawirat, Thunwadee; Mushrifah, Idris

    2015-07-01

    The aim of this study was to determine the source apportionment of dust fall around Lake Chini, Malaysia. Samples were collected monthly between December 2012 and March 2013 at seven sampling stations located around Lake Chini. The samples were filtered to separate the dissolved and undissolved solids. The ionic compositions (NO3-, SO4(2-), Cl- and NH4+) were determined using ion chromatography (IC) while major elements (K, Na, Ca and Mg) and trace metals (Zn, Fe, Al, Ni, Mn, Cr, Pb and Cd) were determined using inductively coupled plasma mass spectrometry (ICP-MS). The results showed that the average concentration of total solids around Lake Chini was 93.49±16.16 mg/(m2·day). SO4(2-), Na and Zn dominated the dissolved portion of the dust fall. The enrichment factors (EF) revealed that the source of the trace metals and major elements in the rain water was anthropogenic, except for Fe. Hierarchical agglomerative cluster analysis (HACA) classified the seven monitoring stations and 16 variables into five groups and three groups respectively. A coupled receptor model, principal component analysis multiple linear regression (PCA-MLR), revealed that the sources of dust fall in Lake Chini were dominated by agricultural and biomass burning (42%), followed by the earth's crust (28%), sea spray (16%) and a mixture of soil dust and vehicle emissions (14%). PMID:26141887

  13. Quantification of the effects of molecular marker oxidation on source apportionment estimates for motor vehicles

    NASA Astrophysics Data System (ADS)

    Roy, Anirban A.; Wagstrom, Kristina M.; Adams, Peter J.; Pandis, Spyros N.; Robinson, Allen L.

    2011-06-01

    Molecular markers are individual organic compounds used in receptor models to apportion fine particulate matter to sources. These models currently assume that molecular markers are chemically stable; however, recent laboratory experiments suggest they may be significantly oxidized on atmospherically relevant time scales. To investigate the effects of photo-oxidation, we extended a 3-D chemical transport model (PMCAMx) to simulate norhopane concentrations over the eastern United States during July 2001. Norhopane is an important molecular marker for motor vehicle exhaust. We examined eight different simulation scenarios, using different combinations of reaction rates and source profiles. The simulations including norhopane oxidation better reproduced the observed spatial patterns of norhopane concentrations than the non-reactive cases. Chemical mass balance (CMB) analysis was performed using the PMCAMx-predicted motor vehicle norhopane and elemental carbon (EC) concentrations to quantify the bias caused by oxidation on source apportionment estimates. Norhopane oxidation caused CMB to underestimate total vehicle OC by 10-50%, with larger biases in rural areas. This underestimation was largely due to changes in the amount of OC apportioned to gasoline vehicles which was reduced by as much as 100%. The OC apportioned to diesel vehicle emissions was relatively insensitive to norhopane reaction. Therefore, oxidation can substantially alter CMB estimates regarding the relative importance of gasoline and diesel vehicle emissions.

  14. Source apportionment of VOCs in the Los Angeles area using positive matrix factorization

    NASA Astrophysics Data System (ADS)

    Brown, Steven G.; Frankel, Anna; Hafner, Hilary R.

    Eight 3-h speciated hydrocarbon measurements were collected daily by the South Coast Air Quality Management District (SCAQMD) as part of the Photochemical Assessment Monitoring Stations (PAMS) program during the summers of 2001-03 at two sites in the Los Angeles air basin, Azusa and Hawthorne. Over 30 hydrocarbons from over 500 samples at Azusa and 600 samples at Hawthorne were subsequently analyzed using the multivariate receptor model positive matrix factorization (PMF). At Azusa and Hawthorne, five and six factors were identified, respectively, with a good comparison between predicted and measured mass. At Azusa, evaporative emissions (a median of 31% of the total mass), motor vehicle exhaust (22%), liquid/unburned gasoline (27%), coatings (17%), and biogenic emissions (3%) factors were identified. Factors identified at Hawthorne were evaporative emissions (a median of 34% of the total mass), motor vehicle exhaust (24%), industrial process losses (15%), natural gas (13%), liquid/unburned gasoline (13%), and biogenic emissions (1%). Together, the median contribution from mobile source-related factors (exhaust, evaporative emissions, and liquid/unburned gasoline) was 80% and 71% at Azusa and Hawthorne, respectively, similar to previous source apportionment results using the chemical mass balance (CMB) model. There is a difference in the distribution among mobile source factors compared to the CMB work, with an increase in the contribution from evaporative emissions, though the cause (changes in emissions or differences between models) is unknown.

  15. Measurement of greenhouse gases (GHGs) and source apportionment in Bakersfield, CA during CALNEX 2010

    NASA Astrophysics Data System (ADS)

    Guha, A.; Gentner, D. R.; Goldstein, A.; Provencal, R. A.; Gardner, A.; Calnex Bakersfield Science Team

    2010-12-01

    The California Global Warming Solutions Act 2006 creates a need to validate and improve the GHG inventory of the State, which has been largely based on activity and emission factor based estimates. As part of CALNEX 2010, we conducted measurements at the Bakersfield supersite of CO2, CH4, and N2O using fast response laser analyzers (LGR Inc.) to document the ambient mixing ratios of GHGs and analyze their major sources in the region, with an emphasis on understanding emissions of methane (CH4) and nitrous oxide (N2O). The site was located downwind of the urban center during the day and usually experienced a reversal of wind direction at night. Bakersfield is an urban area with heavy industrialization including petroleum refineries, oilfields, manufacturing, and cogeneration plants, all of which can be sources of the abovementioned GHGs. The site was close to a highway and potentially subject to vehicular CH4 and N2O emissions. Hence, CO and a broad variety of VOCs, which can serve as tracers (particularly for vehicle emissions), were included in the measurements to help with source apportionment. In addition to typical urban and industrial sources, Kern County is a rich agricultural region and includes a large number of cattle feedlots, dairies, settling ponds and landfills which are assumed to be some of the largest anthropogenic sources of methane in the State. Additionally, the agricultural industry uses significant amounts of fertilizers, which can lead to production of N2O from the soils along with emissions from controlled biomass burning of agricultural waste. The three GHGs studied show a strong diurnal pattern with concentrations building up in the night-time as the planetary boundary layer (PBL) becomes smaller and reversal in wind direction causes the site to become downwind of some GHG sources like landfills and feedlots. The mean background concentrations at the site (CNO2= 323 ppb; CCO2 = 390 ppm) during the day were consistent with those from the

  16. Development of PM2.5 source impact spatial fields using a hybrid source apportionment air quality model

    NASA Astrophysics Data System (ADS)

    Ivey, C. E.; Holmes, H. A.; Hu, Y. T.; Mulholland, J. A.; Russell, A. G.

    2015-01-01

    An integral part of air quality management is knowledge of the impact of pollutant sources on ambient concentrations of particulate matter (PM). There is also a growing desire to directly use source impact estimates in health studies; however, source impacts cannot be directly measured. Several limitations are inherent in most source apportionment methods, which has led to the development of a novel hybrid approach that is used to estimate source impacts by combining the capabilities of receptor modeling (RM) and chemical transport modeling (CTM). The hybrid CTM-RM method calculates adjustment factors to refine the CTM-estimated impact of sources at monitoring sites using pollutant species observations and the results of CTM sensitivity analyses, though it does not directly generate spatial source impact fields. The CTM used here is the Community Multi-Scale Air Quality (CMAQ) model, and the RM approach is based on the Chemical Mass Balance model. This work presents a method that utilizes kriging to spatially interpolate source-specific impact adjustment factors to generate revised CTM source impact fields from the CTM-RM method results, and is applied to January 2004 over the continental United States. The kriging step is evaluated using data withholding and by comparing results to data from alternative networks. Directly applied and spatially interpolated hybrid adjustment factors at withheld monitors had a correlation coefficient of 0.89, a linear regression slope of 0.83 ± 0.02, and an intercept of 0.14 ± 0.02. Refined source contributions reflect current knowledge of PM emissions (e.g., significant differences in biomass burning impact fields). Concentrations of 19 species and total PM2.5 mass were reconstructed for withheld monitors using directly applied and spatially interpolated hybrid adjustment factors. The mean concentrations of total PM2.5 for withheld monitors were 11.7 (± 8.3), 16.3 (± 11), 8.59 (± 4.7), and 9.20 (± 5.7) μg m-3 for the

  17. Characteristics and source apportionment of PM1 emissions at a roadside station.

    PubMed

    Cheng, Y; Zou, S C; Lee, S C; Chow, J C; Ho, K F; Watson, J G; Han, Y M; Zhang, R J; Zhang, F; Yau, P S; Huang, Y; Bai, Y; Wu, W J

    2011-11-15

    The mass concentrations of PM(1) (particles less than 1.0 μm in aerodynamic diameter), organic carbon (OC), elemental carbon (EC), water-soluble ions, and up to 25 elements were reported for 24h aerosol samples collected every sixth day at a roadside sampling station in Hong Kong from October 2004 to September 2005. Annual average PM(1) mass concentration was 44.5 ± 19.5 μg m(-3). EC, OM (organic matter, OC × 1.2), and SO(4)(=) were the dominant components, accounting for ∼ 36%, ∼ 26%, and ∼ 24% of PM(1), respectively. Other components, i.e., NO(3)(-), NH(4)(+), geological material, trace elements and unidentified material, comprised the remaining ∼ 14%. Annual average OC/EC ratio (0.6 ± 0.3) was low, indicating that primary vehicle exhaust was the major source of carbonaceous aerosols. The seasonal variations of pollutants were due to gas-particle partitioning processes or a change in air mass rather than secondary aerosol produced locally. Vehicle exhaust, secondary aerosols, and waste incinerator/biomass burning were dominant air pollution sources, accounting for ∼ 38%, ∼ 22% and ∼ 16% of PM(1), respectively. Pollution episodes during summer (May-August) which were frequently accompanied by tropical storms or typhoons were dominated by vehicle emissions. During winter (November-February) pollution episodes coincided with northeasterly monsoons were characterized by secondary aerosols and incinerator/biomass burning emissions. PMID:21907488

  18. Source apportionment of fluorine pollution in regional shallow groundwater at You'xi County southeast China.

    PubMed

    Lü, Jian; Qiu, Haiyuan; Lin, Huangbin; Yuan, Yuan; Chen, Zhi; Zhao, Rurong

    2016-09-01

    Source apportionment of fluorine pollution in the regional shallow groundwater at You'xi County, southeast China, has been analyzed by means of monitoring F(-) ion change characteristics in this area. Meanwhile, pollution sources and influencing factors of the shallow groundwater have been uncovered by studying the correlation between F(-) and other related ions such as Na(+), Ca(2+), Cl(-), NO3(-), HCO3(-), as well as (K(+) + Na(+))/Ca(2+) ratio (R) and pH effect. The results show that F(-) ions in shallow groundwater at the study area come mainly from the dissolution of fluorinated minerals in a form of fluorite (CaF2), the so-called water-rock interaction, and there is a higher possibility for the occurrence of fluorine water where the ratio of (K(+) + Na(+))/Ca(2+) exceeds a value of 2.1. Moreover, the release and migration of F(-) ions have been favored by the alkaline environment in this study area. PMID:27239970

  19. Using Source Apportionment to Evaluate the Cross State Transport of Ozone in the Eastern United States

    NASA Astrophysics Data System (ADS)

    Goldberg, D. L.; Canty, T. P.; Hembeck, L.; Vinciguerra, T.; Carpenter, S. F.; Anderson, D. C.; Salawitch, R. J.; Dickerson, R. R.

    2014-12-01

    The amount of air pollution crossing state lines has great policy implications. Using the ozone source apportionment tool (OSAT) in the Comprehensive Air-Quality Model with Extensions (CAMx) version 6.10, we can quantify how much ozone is generated locally versus transported from upwind locations. Initial results show that up to 70% of the surface ozone in Maryland during poor air quality days in the summer of July 2011 can be attributed to pollution from outside of the state's borders. Modifications to the CB05 gas-phase chemistry mechanism, supported by literature recommendations and improve agreement with NASA's DISCOVER-AQ Maryland aircraft campaign, can further increase this percentage. Additionally, we show the role of upwind sources and background ozone has become increasingly important as local emissions of ozone precursors continue to drop, starting with the steep reductions imposed in 2002 in response to Maryland's State Implementation Plan submitted to EPA. This study suggests future efforts to control surface ozone must include a meaningful strategy for dealing with cross-state transport of ozone precursors.

  20. Application of hierarchical Bayesian unmixing models in river sediment source apportionment

    NASA Astrophysics Data System (ADS)

    Blake, Will; Smith, Hugh; Navas, Ana; Bodé, Samuel; Goddard, Rupert; Zou Kuzyk, Zou; Lennard, Amy; Lobb, David; Owens, Phil; Palazon, Leticia; Petticrew, Ellen; Gaspar, Leticia; Stock, Brian; Boeckx, Pacsal; Semmens, Brice

    2016-04-01

    Fingerprinting and unmixing concepts are used widely across environmental disciplines for forensic evaluation of pollutant sources. In aquatic and marine systems, this includes tracking the source of organic and inorganic pollutants in water and linking problem sediment to soil erosion and land use sources. It is, however, the particular complexity of ecological systems that has driven creation of the most sophisticated mixing models, primarily to (i) evaluate diet composition in complex ecological food webs, (ii) inform population structure and (iii) explore animal movement. In the context of the new hierarchical Bayesian unmixing model, MIXSIAR, developed to characterise intra-population niche variation in ecological systems, we evaluate the linkage between ecological 'prey' and 'consumer' concepts and river basin sediment 'source' and sediment 'mixtures' to exemplify the value of ecological modelling tools to river basin science. Recent studies have outlined advantages presented by Bayesian unmixing approaches in handling complex source and mixture datasets while dealing appropriately with uncertainty in parameter probability distributions. MixSIAR is unique in that it allows individual fixed and random effects associated with mixture hierarchy, i.e. factors that might exert an influence on model outcome for mixture groups, to be explored within the source-receptor framework. This offers new and powerful ways of interpreting river basin apportionment data. In this contribution, key components of the model are evaluated in the context of common experimental designs for sediment fingerprinting studies namely simple, nested and distributed catchment sampling programmes. Illustrative examples using geochemical and compound specific stable isotope datasets are presented and used to discuss best practice with specific attention to (1) the tracer selection process, (2) incorporation of fixed effects relating to sample timeframe and sediment type in the modelling

  1. AERONET - Aerosol Climatology From Megalopolis Aerosol Source Regions

    NASA Astrophysics Data System (ADS)

    Holben, B. N.; Eck, T. F.; Dubovik, O.; Smirnov, A.; Slutsker, I.; Artaxo, P.; Leyva, A.; Lu, D.; Sano, I.; Singh, R. P.; Quel, E.; Tanre, D.; Zibordi, G.

    2002-05-01

    AERONET is a globally distributed network of ~170 identical sun and sky scanning spectral radiometers expanded by federation with collaborating investigators that contribute to the AERONET public domain data-base. We will detail the current distribution and plans for expanded collaboration. Recent products available through the project database are important for assessment of human health as well as climate forcing issues. We will illustrate a summary of aerosol optical properties measured in Indian, East Asian, North American, South American and European megalopolis source regions. We will present monthly mean fine and coarse particle aerosol optical depth, particle size distributions and single scattering albedos. Each region represents a population in excess of 10 million inhabitants within a 200 km radius of the observation site that dictate the anthropogenic aerosol sources contributing to significantly diverse aerosol properties as a function of economic development and seasonally dependent meteorological processes. The diversity of the measured optical properties of urban aerosols illustrates the need for long-term regional monitoring that contribute to comparative assessments for health and climate change investigations.

  2. Functional group composition of ambient and source organic aerosols determined by tandem mass spectrometry

    NASA Astrophysics Data System (ADS)

    Dron, J.; El Haddad, I.; Temime-Roussel, B.; Jaffrezo, J.-L.; Wortham, H.; Marchand, N.

    2010-04-01

    The functional group composition of various organic aerosols (OA) is being investigated using a recently developed analytical approach based on atmospheric pressure chemical ionisation-tandem mass spectrometry (APCI-MS/MS). The determinations of the three functional groups' contents are performed quantitatively by neutral loss (carboxylic and carbonyl groups) and precursor ion (nitro groups) scanning modes of a tandem mass spectrometer. Major organic aerosol sources are studied: vehicular emission and wood combustion for primary aerosol sources; and a secondary organic aerosol (SOA) produced through photo-oxidation of o-xylene. The results reveal significant differences in the functional group contents of these source aerosols. The laboratory generated SOA is dominated by carbonyls while carboxylics are preponderate in the wood combustion particles. On the other hand, vehicular emissions are characterised by a strong nitro content. The total amount of the three functional groups accounted for 1.7% (vehicular) to 13.5% (o-xylene photo-oxidation) of the organic carbon. The diagnostic functional group ratios are then used to tentatively differentiate sources of particles collected in an urban background environment located in an Alpine valley (Chamonix, France) during a strong winter pollution event. The three functional groups under study account for a total functionalisation rate of 2.2 to 3.8% of the organic carbon in this ambient aerosol, which is also dominated by carboxylic moieties. In this particular case study of a deep alpine valley during winter, we show that the nitro- and carbonyl-to-carboxylic diagnostic ratios can be a useful tool to distinguish the sources. In these conditions, the total OA concentrations are highly dominated by wood combustion OA. This result is confirmed by an organic markers source apportionment approach which assesses a wood burning organic carbon contribution of about 60%. Finally, examples of functional group mass spectra of all

  3. Source apportionment of single particles sampled at the industrially polluted town of Port Talbot, United Kingdom by ATOFMS

    NASA Astrophysics Data System (ADS)

    Taiwo, Adewale M.; Harrison, Roy M.; Beddows, David C. S.; Shi, Zongbo

    2014-11-01

    Single particle analysis of an industrially polluted atmosphere in Port Talbot, South Wales, United Kingdom was conducted using Aerosol-Time-of-Flight Mass Spectrometry (ATOFMS). During the four week sampling campaign, a total of 5,162,018 particles were sized in the size range 0.2-1.9 μm aerodynamic diameter. Of these, 580,798 were successfully ionized generating mass spectra. K-means clustering employed for analysing ATOFMS data utilized 96% of the hit particles to generate 20 clusters. Similar clusters were merged together and 17 clusters were generated from which 7 main particle groups were identified. The particle classes include: K-rich particles (K-CN, K-NO3, K-EC, K-Cl-PO3 and K-HSO4), aged sea salt (Na-NO3), silicate dust (Na-HSiO2), sulphate rich particles (K-HSO4), nitrate rich particles (AlO-NO3), Ca particles (Ca-NO3), carbon-rich particles (Mn-OC, Metallic-EC, EC, EC-NO3 and OC-EC), and aromatic hydrocarbon particles (Arom-CN, Fe-PAH-NO3 and PAH-CN). With the aid of wind sector plots, the K-Cl-PO3 and Na-HSiO2 particle clusters were related to the steelworks blast furnace/sinter plant while Ca-rich particles arose from blast furnace emissions. K-CN, K-EC, Na-HSiO2, K-HSO4, Mn-OC, Arom-CN, Fe-PAH-NO3, and PAH-CN particles were closely linked with emissions from the cokemaking and mills (hot and cold) steelworks sections. The source factors identified by the ATOFMS were compared with those derived from multivariate analysis using Multilinear Engine (ME-2) applied to filter samples analysed off-line. Both methods of source apportionment identified common source factors including those within the steelworks (blast furnace, sinter, cokemaking), as well as marine, traffic and secondary particles, but quantitative attribution of mass is very different.

  4. Size-resolved source apportionment of particulate matter in urban Beijing during haze and non-haze episodes

    NASA Astrophysics Data System (ADS)

    Tian, S. L.; Pan, Y. P.; Wang, Y. S.

    2015-03-01

    More size-resolved chemical information is needed before the physicochemical characteristics and sources of airborne particles can be understood, but this information remains unavailable in most regions of China due to a paucity of measurement data. In this study, we report a one-year observation of various chemical species in size-segregated particle samples collected in urban Beijing, a mega city that experiences severe haze episodes. In addition to fine particles, the measured particle size distributions showed high concentrations of coarse particles during the haze periods. The abundance and chemical compositions of the particles in this study were temporally and spatially variable, with major contributions from organic matter and secondary inorganic aerosols. The contribution of the organic matter to the mass decreased from 37.9 to 33.1%, whereas the total contribution of SO42-, NO3- and NH4+ increased from 19.1 to 32.3% on non-haze and haze days, respectively. Due to heterogeneous reactions and hygroscopic growth, the peaks in the size distributions of organic carbon, SO42-, NO3-, NH4+, Cl-, K+ and Cu shifted from 0.43-0.65 μm on non-haze days to 0.65-1.1 μm on haze days. Although the size distributions are similar for the heavy metals Pb, Cd and Tl during the observation period, their concentrations increased by a factor of more than 1.5 on haze days compared with non-haze days. We found that NH4+ with a size range of 0.43-0.65 μm, SO42- and NO3- with a size range of 0.65-1.1 μm and Ca2+ with a size range of 5.8-9 μm as well as the meteorological factors of relative humidity and wind speed were responsible for the haze pollution when the visibility was less than 15 km. Source apportionment using positive matrix factorization identified six common sources: secondary inorganic aerosols (26.1% for fine particles vs. 9.5% for coarse particles), coal combustion (19 vs. 23.6%), primary emissions from vehicles (5.9 vs. 8.0%), biomass burning (8.5 vs. 2

  5. Source apportionment of arsenic in atmospheric dust fall out in an urban residential area, Raipur, Central India

    NASA Astrophysics Data System (ADS)

    Balakrishna, G.; Pervez, S.; Bisht, D. S.

    2011-06-01

    The components and quantities of atmospheric dust fallout have been reported to be the pollution indicator of large urban areas. The multiplicity and complexity of sources of atmospheric dusts in urban regions has put forward the need of source apportionment of these sources indicating their contribution to specific environmental receptor. The study presented here is focused on investigation of source contribution estimates of Arsenic in urban dust fallout in an urban-industrial area, Raipur, India. Source-receptor based representative sampling plan using longitudinal study design has been adopted. Six sampling sites have been identified on the basis of land use for development plan of anthropogenic activities and factors related to the transportation and dispersion pattern of atmospheric dusts. Source apportionment has been done using Chemical Mass Balance (CMB 8). Good fit parameters and relative source contribution has been analyzed and documented. Dominance of coal fired industries sources on arsenic levels measured at selected ambient residential receptors compared to line sources has been observed. Road-traffic has shown highest contribution of dust at indoor houses and out door-street automobile exhaust has shows highest contribution for arsenic. The results of CMB output and regression data of source-receptor dust matrices have shown comparable pattern.

  6. Connecting Organic Aerosol Climate-Relevant Properties to Chemical Mechanisms of Sources and Processing

    SciTech Connect

    Thornton, Joel

    2015-01-26

    The research conducted on this project aimed to improve our understanding of secondary organic aerosol (SOA) formation in the atmosphere, and how the properties of the SOA impact climate through its size, phase state, and optical properties. The goal of this project was to demonstrate that the use of molecular composition information to mechanistically connect source apportionment and climate properties can improve the physical basis for simulation of SOA formation and properties in climate models. The research involved developing and improving methods to provide online measurements of the molecular composition of SOA under atmospherically relevant conditions and to apply this technology to controlled simulation chamber experiments and field measurements. The science we have completed with the methodology will impact the simulation of aerosol particles in climate models.

  7. Apportionment of primary and secondary organic aerosols in southern California during the 2005 study of organic aerosols in riverside (SOAR-1).

    PubMed

    Docherty, Kenneth S; Stone, Elizabeth A; Ulbrich, Ingrid M; DeCarlo, Peter F; Snyder, David C; Schauer, James J; Peltier, Richard E; Weber, Rodney J; Murphy, Shane M; Seinfeld, John H; Grover, Brett D; Eatough, Delbert J; Jimenez, Jose L

    2008-10-15

    Ambient sampling was conducted in Riverside, California during the 2005 Study of Organic Aerosols in Riverside to characterize the composition and sources of organic aerosol using a variety of state-of-the-art instrumentation and source apportionmenttechniques. The secondary organic aerosol (SOA) mass is estimated by elemental carbon and carbon monoxide tracer methods, water soluble organic carbon content, chemical mass balance of organic molecular markers, and positive matrix factorization of high-resolution aerosol mass spectrometer data. Estimates obtained from each ofthese methods indicate that the organic fraction in ambient aerosol is overwhelmingly secondary in nature during a period of several weeks with moderate ozone concentrations and that SOA is the single largest component of PM1 aerosol in Riverside. Average SOA/OA contributions of 70-90% were observed during midday periods, whereas minimum SOA contributions of approximately 45% were observed during peak morning traffic periods. These results are contraryto previous estimates of SOAthroughout the Los Angeles Basin which reported that, other than during severe photochemical smog episodes, SOA was lower than primary OA. Possible reasons for these differences are discussed. PMID:18983089

  8. Source apportionment of particulate pollutants in the atmosphere over the Northern Yellow Sea

    NASA Astrophysics Data System (ADS)

    Wang, L.; Qi, J. H.; Shi, J. H.; Chen, X. J.; Gao, H. W.

    2013-05-01

    Atmospheric aerosol samples were collected over the Northern Yellow Sea of China during the years of 2006 and 2007, in which the Total Carbon (TC), Cu, Pb, Cd, V, Zn, Fe, Al, Na+, Ca2+, Mg2+, NH4+, NO3-, SO42-, Cl-, and K+ were measured. The principle components analysis (PCA) and positive matrix factorization (PMF) receptor models were used to identify the sources of particulate matter. The results indicated that seven factors contributed to the atmospheric particles over the Northern Yellow Sea, i.e., two secondary aerosols (sulfate and nitrate), soil dust, biomass burning, oil combustion, sea salt, and metal smelting. When the whole database was considered, secondary aerosol formation contributed the most to the atmospheric particle content, followed by soil dust. Secondary aerosols and soil dust consisted of 65.65% of the total mass of particulate matter. The results also suggested that the aerosols over the North Yellow Sea were heavily influenced by ship emission over the local sea area and by continental agricultural activities in the northern China, indicating by high loading of V in oil combustion and high loading of K+ in biomass burning. However, the contribution of each factor varied greatly over the different seasons. In spring and autumn, soil dust and biomass burning were the dominant factors. In summer, heavy oil combustion contributed the most among these factors. In winter, secondary aerosols were major sources. Backward trajectories analysis indicated the 66% of air mass in summer was from the ocean, while the air mass is mainly from the continent in other seasons.

  9. Measurement and apportionment of radon source terms for modeling indoor environments

    SciTech Connect

    Harley, N.H.

    1992-01-01

    During the present 2 1/2 year contract period, we have made significant Progress in modeling the source apportionment of indoor [sup 222]Rn and in [sup 222]Rn decay product dosimetry. Two additional areas were worked on which we believe are useful for the DOE Radon research Program. One involved an analysis of the research house data, grouping the hourly house [sup 222]Rn measurements into 2 day, 7 day and 90 day intervals to simulate the response of passive monitors. Another area requiring some attention resulted in a publication of 3 years of our indoor/outdoor measurements in a high-rise apartment. Little interest has been evinced in apartment measurements yet 20% of the US population lives in multiple-family dwellings, not in contact with the ground. These data together with a summary of all other published data on apartments showed that apartments have only about 50% greater [sup 222]Rn concentration than the measured outdoor [sup 222]Rn. Apartment dwellers generally represent a low risk group regarding [sup 222]Rn exposure. The following sections describe the main projects in some detail.

  10. [Characteristics and sources apportionment of OC and EC in PM1.1 from Nanjing].

    PubMed

    Jiang, Wen-juan; Guo, Zhao-bing; Liu, Feng-ling; Rui, Mao-ling; Shi, Lei; Zeng, Gang; Guo, Zi-yan

    2015-03-01

    The concentrations of OC and EC in PM1.1 collected from Nanshi (NS) and Nanhua (NH) in 2011 were analyzed using DRI Model 2001A Thermal Optical Carbon Analyzer. In addition, source apportionment was simultaneously evaluated. The results showed that the annual average concentrations of OC and EC in PM1.1 were 10. 10 μg x m(-3) and 2.52 μg x m(-3) in NS area, and 11.22 μg x m(-3) and 3.12 μg x m(-3) in NH area, respectively. This result indicated that OC and EC pollution in NH was more serious than that in NS area. Meanwhile, the concentrations of OC and EC in winter and spring were obviously higher compared to those in summer in these two sampling sites, which was mainly ascribed to the increased coal combustion and the unfavorable emission condition of air pollutants in summer and spring. We noted that the SOC/TOC value was the highest in summer and the lowest in winter. In addition, the SOC concentration was observed to show a positive correlation with ozone concentrations, which indicated that the photochemical reaction was a main way of SOC formation in autumn. PMID:25929040

  11. Receptor model-based source apportionment of particulate pollution in Hyderabad, India.

    PubMed

    Guttikunda, Sarath K; Kopakka, Ramani V; Dasari, Prasad; Gertler, Alan W

    2013-07-01

    Air quality in Hyderabad, India, often exceeds the national ambient air quality standards, especially for particulate matter (PM), which, in 2010, averaged 82.2 ± 24.6, 96.2 ± 12.1, and 64.3 ± 21.2 μg/m(3) of PM10, at commercial, industrial, and residential monitoring stations, respectively, exceeding the national ambient standard of 60 μg/m(3). In 2005, following an ordinance passed by the Supreme Court of India, a source apportionment study was conducted to quantify source contributions to PM pollution in Hyderabad, using the chemical mass balance (version 8.2) receptor model for 180 ambient samples collected at three stations for PM10 and PM2.5 size fractions for three seasons. The receptor modeling results indicated that the PM10 pollution is dominated by the direct vehicular exhaust and road dust (more than 60%). PM2.5 with higher propensity to enter the human respiratory tracks, has mixed sources of vehicle exhaust, industrial coal combustion, garbage burning, and secondary PM. In order to improve the air quality in the city, these findings demonstrate the need to control emissions from all known sources and particularly focus on the low-hanging fruits like road dust and waste burning, while the technological and institutional advancements in the transport and industrial sectors are bound to enhance efficiencies. Andhra Pradesh Pollution Control Board utilized these results to prepare an air pollution control action plan for the city. PMID:23132755

  12. Nutrient and trace metals atmospheric deposition in the western Mediterranean: source apportionment

    NASA Astrophysics Data System (ADS)

    Desboeufs, Karine; Bon Nguyen, Elisabeth; Simeoni, Pasquale; Dulac, François

    2015-04-01

    Mediterranean Sea is a typical LNLC region particularly well adapted to assess the role of ocean-atmosphere exchanges. Throughout the summer stratification period when diffusion through the thermocline is low, atmospheric inputs become the main external source of nutrients to the surface open waters of the MS, mostly by wet deposition in the western basin.Here, we show a 3-yr time continuous series of nutrient (N, P) and trace metals (Cr, Cu, Fe, P, V, Zn) total deposition fluxes in Corsica. Between March 2008 and May 2011, a monitoring station was operated with a weekly sampling time step at Galeria (42.44°N; 8.65°E) on the western coast of Corsica in the framework of the projects DUNE (a Dust Experiment in a Low Nutrient Low Chlorophyll Ecosystem) and then ChArMEx (the Chemistry-Aerososl Mediterranean Experiment). Monthly fluxes were measured to assess the temporal variability of the measured elements over the Western Mediterranean. Nutrients deposition presented a clear seasonal pattern which was different for each studied nutrients, emphasizing a difference of sources for the nutrients. The results show no dust event larger than 0.68 g m-2 so that the maximum yearly flux was among the lowest ever observed in Corsica (1.7 g m-2 y-1). One dust deposition event could contribute up to 30% of yearly deposition fluxes of nutrient and trace metals, confirming the high temporal variability of atmospheric deposition. However a source apportionment work via statistical methods shows that the yearly deposition fluxes of considered nutrient and trace metals were dominated by anthropogenic sources, except for Fe. Acknowledgements: DUNE project was funded by ANR. ChArMEx (http://charmex.lsce.ipsl.fr) is funded by CNRS/INSU, ADEME, CEA and Météo-France in the framework of the programme MISTRALS (http://www.mistrals-home.org)

  13. Source apportionment and water solubility of metals in size segregated particles in urban environments.

    PubMed

    Jiang, Sabrina Yanan; Kaul, Daya S; Yang, Fenhuan; Sun, Li; Ning, Zhi

    2015-11-15

    Metals in atmospheric particulate matter (PM) have been associated with various adverse health effects. Different factors contributing to the characterization and distribution of atmospheric metals in urban environments lead to uncertainty of the understanding of their impact on public health. However, few studies have provided a comprehensive picture of the spatial and seasonal variability of metal concentration, solubility and size distribution, all of which have important roles in their contribution to health effects. This study presents an experimental investigation on the characteristics of metals in PM2.5 and coarse PM in two seasons from four urban sites in Hong Kong. The PM samples were extracted separately with aqua regia and water, and a total of sixteen elements were analyzed using ICP-MS and ICP-OES to determine the size segregated concentration and solubility of metals. The concentrations of major metals were distributed in similar patterns with the same order of magnitude among different urban sites. Source apportionment using Positive Matrix Factorization (PMF) indicated that three sources namely road dust, vehicular exhaust and ship emission are major contributors to the urban atmospheric metal concentrations in Hong Kong with distinctly different profiles between coarse PM and PM2.5 fractions. The individual metals were assigned to different sources, consistent with literature documentation, except potassium emerging with substantial contribution from vehicle exhaust emission. Literature data from past studies on both local and other cities were compared to the results from the present study to investigate the impact of different emission sources and control policies on metal distribution in urban atmosphere. A large variation of solubility among the metals reflected that the majority of metals in PM2.5 were more soluble than those in coarse PM indicating size dependent chemical states of metals. The data from this study provides a rich dataset of

  14. Source regional contributions to PM2.5 in a megacity in China using an advanced source regional apportionment method.

    PubMed

    Tian, Ying-Ze; Chen, Gang; Wang, Hai-Ting; Huang-Fu, Yan-Qi; Shi, Guo-Liang; Han, Bo; Feng, Yin-Chang

    2016-03-01

    To quantify contributions of individual source categories from diverse regions to PM2.5, PM2.5 samples were collected in a megacity in China and analyzed through a newly developed source regional apportionment (SRA) method. Levels, compositions and seasonal variations of speciated PM2.5 dataset were investigated. Sources were determined by Multilinear Engine 2 (ME2) model, and results showed that the PM2.5 in Tianjin was mainly influenced by secondary sulphate & secondary organic carbon SOC (percent contribution of 26.2%), coal combustion (24.6%), crustal dust & cement dust (20.3%), secondary nitrate (14.9%) and traffic emissions (14.0%). The SRA method showed that northwest region R2 was the highest regional contributor to secondary sources, with percent contributions to PM2.5 being 9.7% for secondary sulphate & SOC and 6.0% for secondary nitrates; the highest coal combustion was from local region R1 (6.2%) and northwest R2 (8.0%); the maximum contributing region to crustal & cement dust was southeast region R4 (5.0%); and contributions of traffic emissions were relatively spatial homogeneous. The seasonal variation of regional source contributions was observed: in spring, the crustal and cement dust contributed a higher percentage and the R4 was an important contributor; the secondary process attributed an increase fraction in summer; the mixed coal combustion from southwest R5 enhanced in autumn. PMID:26766363

  15. Chemical apportionment of aerosol optical properties during the Asia-Pacific Economic Cooperation summit in Beijing, China

    NASA Astrophysics Data System (ADS)

    Han, Tingting; Xu, Weiqi; Chen, Chen; Liu, Xingang; Wang, Qingqing; Li, Jie; Zhao, Xiujuan; Du, Wei; Wang, Zifa; Sun, Yele

    2015-12-01

    , the contribution of primary aerosol to particle extinction increased from 26.8% to 39.6%, elucidating an enhanced role of local primary sources in visibility deterioration during APEC. Further analysis of chemically resolved particle extinction showed that the extinction contributions of aerosol species varied greatly between different air masses but generally with ammonium nitrate, ammonium sulfate, and secondary OA being the three major contributors.

  16. Overview of receptor-based source apportionment studies for speciated atmospheric mercury

    NASA Astrophysics Data System (ADS)

    Cheng, I.; Xu, X.; Zhang, L.

    2015-07-01

    Receptor-based source apportionment studies of speciated atmospheric mercury are not only concerned with source contributions but also with the influence of transport, transformation, and deposition processes on speciated atmospheric mercury concentrations at receptor locations. Previous studies applied multivariate receptor models including principal components analysis and positive matrix factorization, and back trajectory receptor models including potential source contribution function, gridded frequency distributions, and concentration-back trajectory models. Combustion sources (e.g., coal combustion, biomass burning, and vehicular, industrial and waste incineration emissions), crustal/soil dust, and chemical and physical processes, such as gaseous elemental mercury (GEM) oxidation reactions, boundary layer mixing, and GEM flux from surfaces were inferred from the multivariate studies, which were predominantly conducted at receptor sites in Canada and the US. Back trajectory receptor models revealed potential impacts of large industrial areas such as the Ohio River valley in the US and throughout China, metal smelters, mercury evasion from the ocean and the Great Lakes, and free troposphere transport on receptor measurements. Input data and model parameters specific to atmospheric mercury receptor models are summarized and model strengths and weaknesses are also discussed. Multivariate models are suitable for receptor locations with intensive air monitoring because they require long-term collocated and simultaneous measurements of speciated atmospheric Hg and ancillary pollutants. The multivariate models provide more insight about the types of Hg emission sources and Hg processes that could affect speciated atmospheric Hg at a receptor location, whereas back trajectory receptor models are mainly ideal for identifying potential regional Hg source locations impacting elevated Hg concentrations. Interpretation of the multivariate model output to sources can be

  17. Reactive oxygen species associated with water-soluble PM2.5 in the southeastern United States: spatiotemporal trends and source apportionment

    NASA Astrophysics Data System (ADS)

    Verma, V.; Fang, T.; Guo, H.; King, L.; Bates, J. T.; Peltier, R. E.; Edgerton, E.; Russell, A. G.; Weber, R. J.

    2014-12-01

    We assess the potential of the water-soluble fraction of atmospheric fine aerosols in the southeastern United States to generate reactive oxygen species (ROS) and identify major ROS-associated emission sources. ROS-generation potential of particles was quantified by the dithiothreitol (DTT) assay and involved analysis of fine particulate matter (PM) extracted from high-volume quartz filters (23 h integrated samples) collected at various sites in different environmental settings in the southeast, including three urban-Atlanta sites, in addition to a rural site. Paired sampling was conducted with one fixed site in Atlanta (Jefferson Street), representative of the urban environment, with the others rotating among different sites, for ~250 days between June 2012 and September 2013 (N=483). A simple linear regression between the DTT activity and aerosol chemical components revealed strong associations between PM ROS-generation potential and secondary organic aerosol (WSOC - water-soluble organic carbon) in summer, and biomass burning markers in winter. Redox-active metals were also somewhat correlated with the DTT activity, but mostly at urban and roadside sites. Positive matrix factorization (PMF) was applied to apportion the relative contribution of various sources to the ROS-generation potential of water-soluble PM2.5 in urban Atlanta. PMF showed that vehicular emissions contribute uniformly throughout the year (12-25%), while secondary oxidation processes dominated the DTT activity in summer (46%) and biomass burning in winter (47%). Road dust was significant only during drier periods (~12% in summer and fall). Source apportionment by chemical mass balance (CMB) was reasonably consistent with PMF, but with higher contribution from vehicular emissions (32%). Given the spatially large data set of PM sampled over an extended period, the study reconciles the results from previous work that showed only region- or season-specific aerosol components or sources contributing

  18. Reactive oxygen species associated with water-soluble PM2.5 in the southeastern United States: spatiotemporal trends and source apportionment

    NASA Astrophysics Data System (ADS)

    Verma, V.; Fang, T.; Guo, H.; King, L.; Bates, J. T.; Peltier, R. E.; Edgerton, E.; Russell, A. J.; Weber, R. J.

    2014-07-01

    We assess the potential of the water-soluble fraction of atmospheric fine aerosols in the southeastern US to generate reactive oxygen species (ROS) and identify major ROS-associated emission sources. ROS-generation potential of particles was quantified by the dithiothreitol (DTT) assay and involved analysis of fine particulate matter (PM) extracted from high-volume quartz filters (23 h integrated samples) collected at various sites in different environmental settings in the southeast, including three urban Atlanta sites, in addition to a rural site. Paired sampling was conducted with one fixed site in Atlanta (Jefferson Street), representative of the urban environment, with the others rotating among different sites, for ~250 days between June 2012 and September 2013 (N = 483). A simple linear regression between the DTT activity and aerosol chemical components revealed strong associations between PM ROS generation potential and secondary organic aerosol (WSOC) in summer, and biomass burning markers in winter. Redox-active metals were also correlated with the DTT activity, but mostly at urban and roadside sites. Positive matrix factorization (PMF) was applied to apportion the relative contribution of various sources to the ROS generation potential of water-soluble PM2.5 in urban Atlanta. PMF showed that vehicular emissions contribute uniformly throughout the year (12 to 25%), while secondary oxidation processes dominated the DTT activity in summer (46%) and biomass burning in winter (47%). Mineral dust was significant only during drier periods (~12% in summer and fall). Source apportionment by chemical mass balance (CMB) was reasonably consistent with PMF, but with higher contribution from vehicular emissions (32%). Given the spatially large data set of PM sampled over an extended period, the study reconciles the results from previous work that showed only region- or season-specific aerosol components or sources contributing to PM ROS activity, possibly due to

  19. Chemical characteristics and source apportionment of fine particulate organic carbon in Hong Kong during high particulate matter episodes in winter 2003

    NASA Astrophysics Data System (ADS)

    Li, Yun-Chun; Yu, Jian Zhen; Ho, Steven Sai Hang; Schauer, James J.; Yuan, Zibing; Lau, Alexis K. H.; Louie, Peter K. K.

    2013-02-01

    PM2.5 samples were collected at six general stations and one roadside station in Hong Kong in two periods of high particulate matter (PM) in 2003 (27 October-4 November and 30 November-13 December). The highest PM2.5 reached 216 μg m- 3 during the first high PM period and 113 μg m- 3 during the second high PM period. Analysis of synoptic weather conditions identified individual sampling days under dominant influence of one of three types of air masses, that is, local, regional and long-range transported (LRT) air masses. Roadside samples were discussed separately due to heavy influences from vehicular emissions. This research examines source apportionment of fine organic carbon (OC) and contribution of secondary organic aerosol on high PM days under different synoptic conditions. Six primary OC (POC) sources (vehicle exhaust, biomass burning, cooking, cigarette smoke, vegetative detritus, and coal combustion) were identified on the basis of characteristic organic tracers. Individual POC source contributions were estimated using chemical mass balance model. In the roadside and the local samples, OC was dominated by the primary sources, accounting for more than 74% of OC. In the samples influenced by regional and LRT air masses, secondary OC (SOC), which was approximated to be the difference between the total measured OC and the apportioned POC, contributed more than 54% of fine OC. SOC was highly correlated with water-soluble organic carbon and sulfate, consistent with its secondary nature.

  20. Chemical composition of aerosol particles and light extinction apportionment before and during the heating season in Beijing, China

    NASA Astrophysics Data System (ADS)

    Wang, Qingqing; Sun, Yele; Jiang, Qi; Du, Wei; Sun, Chengzhu; Fu, Pingqing; Wang, Zifa

    2015-12-01

    Despite extensive efforts into characterization of the sources and formation mechanisms of severe haze pollution in the megacity of Beijing, the response of aerosol composition and optical properties to coal combustion emissions in the heating season remain poorly understood. Here we conducted a 3 month real-time measurement of submicron aerosol (PM1) composition by an Aerosol Chemical Speciation Monitor and particle light extinction by a Cavity Attenuated Phase Shift extinction monitor in Beijing, China, from 1 October to 31 December 2012. The average (±σ) PM1 concentration was 82.4 (±73.1) µg/m3 during the heating period (HP, 15 November to 31 December), which was nearly 50% higher than that before HP (1 October to 14 November). While nitrate and secondary organic aerosol (SOA) showed relatively small changes, organics, sulfate, and chloride were observed to have significant increases during HP, indicating the dominant impacts of coal combustion sources on these three species. The relative humidity-dependent composition further illustrated an important role of aqueous-phase processing for the sulfate enhancement during HP. We also observed great increases of hydrocarbon-like OA (HOA) and coal combustion OA (CCOA) during HP, which was attributed to higher emissions at lower temperatures and coal combustion emissions, respectively. The relationship between light extinction and chemical composition was investigated using a multiple linear regression model. Our results showed that the largest contributors to particle extinction were ammonium nitrate (32%) and ammonium sulfate (28%) before and during HP, respectively. In addition, the contributions of SOA and primary OA to particle light extinction were quantified. The results showed that the OA extinction was mainly caused by SOA before HP and by SOA and CCOA during HP, yet with small contributions from HOA and cooking aerosol for the entire study period. Our results elucidate substantial changes of aerosol

  1. Successful application of lead isotopes in source apportionment, legal proceedings, remediation and monitoring

    SciTech Connect

    Gulson, Brian; Korsch, Michael; Winchester, Wayne; Devenish, Matthew; Hobbs, Thad; Main, Cleve; Smith, Gerard; Rosman, Kevin; Howearth, Lynette; Burn-Nunes, Laurie; Seow, Jimmy; Oxford, Cameron; Yun, Gracie; Gillam, Lindsay; Crisp, Michelle

    2012-01-15

    In late 2006, the seaside community in Esperance Western Australia was alerted to thousands of native bird species dying. The source of the lead (Pb) was determined by Pb isotopes to derive from the handling of Pb carbonate concentrate through the Port, which began in July 2005. Concern was expressed for the impact of this on the community. Our objectives were to employ Pb isotope ratios to evaluate the source of Pb in environmental samples for use in legal proceedings, and for use in remediation and monitoring. Isotope measurements were undertaken of bird livers, plants, drinking water, soil, harbour sediments, air, bulk ceiling dust, gutter sludge, surface swabs and blood. The unique lead isotopic signature of the contaminating Pb carbonate enabled diagnostic apportionment of lead in samples. Apart from some soil and water samples, the proportion of contaminating Pb was >95% in the environmental samples. Lead isotopes were critical in resolving legal proceedings, are being used in the remediation of premises, were used in monitoring of workers involved in the decontamination of the storage facility, and monitoring transport of the concentrate through another port facility. Air samples show the continued presence of contaminant Pb, more than one year after shipping of concentrate ceased, probably arising from dust resuspension. Brief details of the comprehensive testing and cleanup of the Esperance community are provided along with the role of the Community. Lead isotopic analyses can provide significant benefits to regulatory agencies, interested parties, and the community where the signature is able to be characterised with a high degree of certainty. - Highlights: Black-Right-Pointing-Triangle Lead carbonate concentrate. Black-Right-Pointing-Triangle Successful use of Pb isotopes in identifying sources of Pb arising from transport and shipping. Black-Right-Pointing-Triangle Use of Pb isotopes in legal proceedings and their use in cleanup of residences. Black

  2. Evaluation of Particulate Matter Source Apportionment Forecasts during the MAPS-Seoul Field Campaign

    NASA Astrophysics Data System (ADS)

    Bae, C.; Kim, S.; Kim, H. C.; Kim, B. U.

    2015-12-01

    We report forecasting model performance analysis results of Comprehensive Air quality Model with extensions (CAMx) simulation evaluated with flight measurements during Megacity Air Pollution Studies-Seoul (MAPS-Seoul) field campaign. The primary focus of this study is two-fold: (1) the air quality forecasting model performance for O3, PM10/2.5 and their precursors over the Yellow Sea to measure the model's ability to account for the transport process and (2) the utilization of modeled source-receptor relationship to understand the root of systematic model under-prediction for PM10 and PM2.5 forecasts. MAPS-Seoul, conducted in the Seoul Metropolitan Area (SMA) in the summer of 2015, was an integrated research program covering ground monitoring and aloft measurement with aircrafts. To support this field campaign, air quality forecasting was performed with Weather Research and Forecasting (WRF) - Sparse Matrix Operator Kernel Emissions (SMOKE) - CAMx modeling framework. WRF model simulations initialized with National Centers for Environmental Prediction Global Forecasting System (NOAA/NCEP-GFS) were prepared for daily meteorological forecasts. Emission inventories used in this study are Model Inter-Comparison Study-Asia (MICS-Asia) 2010 for Asia and Clean Air Policy Support System (CAPSS) 2010 for South Korea. Simulated PM10 concentrations were evaluated with observed PM10 concentrations at ground monitoring sites of the AirKorea network in SMA. During the campaign period, average simulated PM10 concentrations showed significant underprediction, over 30% (~35 ㎍/㎥) lower than those observed at sites. To examine source-receptor relationship as a way to identify the cause of underprediction, we ran CAMx with Particulate matter Source Apportionment Technology (PSAT). The air quality forecasting model is based on the with 27-km horizontal grid resolution over Northeast Asia.

  3. Hydrocarbon source apportionment for the 1996 Paso del Norte ozone study

    SciTech Connect

    Fujita, E.M.

    1999-07-01

    This paper provides a summary of the nonmethane hydrocarbon (NMHC) source apportionments performed at Desert Research Institute as part of the 1996 Paso del Norte Ozone Study. Version 8 of the Chemical Mass Balance (CMB) receptor model was applied to a total of 2232 hourly automated gas chromatography (auto-GC) and 225 two-hour canister samples. The auto-GC system was operated by the Texas Natural Resource Conservation Commission at one site in central El Paso. Two-hour canister samples were collected five times per day at 0500--0700, 0700--0900, 0900--1100, 1100--1300, and 1500--1700 MST during intensive study periods at one urban and one rural site on each side of the border. Gasoline vehicle exhaust accounts for one-half to two-thirds of NMHC in Juarez and El Paso with highest contributions during the morning and afternoon commute periods. Emissions from diesel exhaust and propane buses are both 2 to 5% of NMHC in Juarez and less than 2% in El Paso. The average sum of liquid gasoline and gasoline vapor increases during the day in Juarez from 2% at 0600 to about 8% at 1600. Diurnal and day-of-the-week patterns in the liquid gasoline contributions are essentially identical to the corresponding patterns for motor vehicle exhaust. These patterns suggest that a large fraction of the liquid gasoline contribution is associated with tailpipe emissions rather than evaporative emissions from either vehicle or industrial sources. Additionally, the contributions of liquid gasoline are strongly correlated with vehicle exhaust with respect to wind direction. The sum of the two sources put the upper limit for tailpipe contributions at 60 to 70%t of NMHC.

  4. GIS-based source identification and apportionment of diffuse water pollution: perfluorinated compound pollution in the Tokyo Bay basin.

    PubMed

    Zushi, Yasuyuki; Masunaga, Shigeki

    2011-11-01

    To efficiently reduce perfluorinated compound (PFC) pollution, it is important to have an understanding of PFC sources and their contribution to the pollution. In this study, source identification of diffuse water pollution by PFCs was conducted using a GIS-based approach. Major components of the source identification were collection of the monitoring data and preparation of the corresponding geographic information that was extracted from a constructed GIS database. The spatially distributed pollution factors were then explored by multiple linear regression analysis, after which they were visually expressed using GIS. Among the 35 PFC homologues measured in a survey of the Tokyo Bay basin, 18 homologues were analyzed. Pollution by perfluorooctane sulfonate (PFOS) was explained well by the percentage of arterial traffic area in the basin, and the 84% variance of the measured PFOS concentration was explained by two geographic variables, arterial traffic area and population. Source apportionment between point and nonpoint sources was conducted based on the results of the analysis. The contribution of PFOS from nonpoint sources was comparable to that from point sources in several major rivers flowing into Tokyo Bay. Source identification and apportionment using the GIS-based approach was shown to be effective, especially for ubiquitous types of pollution, such as PFC pollution. PMID:21885084

  5. Integrating Source Apportionment Tracers into a Bottom-up Inventory of Methane Emissions in the Barnett Shale Hydraulic Fracturing Region.

    PubMed

    Townsend-Small, Amy; Marrero, Josette E; Lyon, David R; Simpson, Isobel J; Meinardi, Simone; Blake, Donald R

    2015-07-01

    A growing dependence on natural gas for energy may exacerbate emissions of the greenhouse gas methane (CH4). Identifying fingerprints of these emissions is critical to our understanding of potential impacts. Here, we compare stable isotopic and alkane ratio tracers of natural gas, agricultural, and urban CH4 sources in the Barnett Shale hydraulic fracturing region near Fort Worth, Texas. Thermogenic and biogenic sources were compositionally distinct, and emissions from oil wells were enriched in alkanes and isotopically depleted relative to natural gas wells. Emissions from natural gas production varied in δ(13)C and alkane ratio composition, with δD-CH4 representing the most consistent tracer of natural gas sources. We integrated our data into a bottom-up inventory of CH4 for the region, resulting in an inventory of ethane (C2H6) sources for comparison to top-down estimates of CH4 and C2H6 emissions. Methane emissions in the Barnett are a complex mixture of urban, agricultural, and fossil fuel sources, which makes source apportionment challenging. For example, spatial heterogeneity in gas composition and high C2H6/CH4 ratios in emissions from conventional oil production add uncertainty to top-down models of source apportionment. Future top-down studies may benefit from the addition of δD-CH4 to distinguish thermogenic and biogenic sources. PMID:26148556

  6. Novel measurement technologies for ambient and combustion source aerosols

    EPA Science Inventory

    Thie presentaiton examines the chemical properties of atmospheric and combustion source aerosols. It describes the aerosol chemical fractions and the specific chemical constituents in these aerosols. The presentation will cover (i) the limitatins and benefits of hyphenated chroma...

  7. Chemical mass balance source apportionment for combined PM 2.5 measurements from U.S. non-urban and urban long-term networks

    NASA Astrophysics Data System (ADS)

    Antony Chen, L.-W.; Watson, John G.; Chow, Judith C.; DuBois, David W.; Herschberger, Lisa

    2010-12-01

    The Minnesota Particulate Matter 2.5 (PM 2.5) Source Apportionment Study was undertaken to explore the utility of PM 2.5 mass, element, ion, and carbon measurements from long-term speciation networks for pollution source attribution. Ambient monitoring data at eight sites across the state were retrieved from the archives of the Interagency Monitoring of Protected Visual Environments (IMPROVE) and the Speciation Trends Network (STN; part of the Chemical Speciation Network [CSN]) and analyzed by an Effective Variance - Chemical Mass Balance (EV-CMB) receptor model with region-specific geological source profiles developed in this study. PM 2.5 was apportioned into contributions of fugitive soil dust, calcium-rich dust, taconite (low grade iron ore) dust, road salt, motor vehicle exhaust, biomass burning, coal-fired utility, and secondary aerosol. Secondary sulfate and nitrate contributed strongly (49-71% of PM 2.5) across all sites and was dominant (≥60%) at IMPROVE sites. Vehicle exhausts accounted for 20-70% of the primary PM 2.5 contribution, largely exceeding the proportion in the primary PM 2.5 emission inventory. The diesel exhaust contribution was separable from the gasoline engine exhaust contribution at the STN sites. Higher detection limits for several marker elements in the STN resulted in non-detectable coal-fired boiler contributions which were detected in the IMPROVE data. Despite the different measured variables, analytical methods, and detection limits, EV-CMB results from a nearby IMPROVE-STN non-urban/urban sites showed similar contributions from regional sources - including fugitive dust and secondary aerosol. Seasonal variations of source contributions were examined and extreme PM 2.5 episodes were explained by both local and regional pollution events.

  8. Source apportionment and location by selective wind sampling and Positive Matrix Factorization.

    PubMed

    Venturini, Elisa; Vassura, Ivano; Raffo, Simona; Ferroni, Laura; Bernardi, Elena; Passarini, Fabrizio

    2014-10-01

    In order to determine the pollution sources in a suburban area and identify the main direction of their origin, PM2.5 was collected with samplers coupled with a wind select sensor and then subjected to Positive Matrix Factorization (PMF) analysis. In each sample, soluble ions, organic carbon, elemental carbon, levoglucosan, metals, and Polycyclic Aromatic Hydrocarbons (PAHs) were determined. PMF results identified six main sources affecting the area: natural gas home appliances, motor vehicles, regional transport, biomass combustion, manufacturing activities, and secondary aerosol. The connection of factor temporal trends with other parameters (i.e., temperature, PM2.5 concentration, and photochemical processes) confirms factor attributions. PMF analysis indicated that the main source of PM2.5 in the area is secondary aerosol. This should be mainly due to regional contributions, owing to both the secondary nature of the source itself and the higher concentration registered in inland air masses. The motor vehicle emission source contribution is also important. This source likely has a prevalent local origin. The most toxic determined components, i.e., PAHs, Cd, Pb, and Ni, are mainly due to vehicular traffic. Even if this is not the main source in the study area, it is the one of greatest concern. The application of PMF analysis to PM2.5 collected with this new sampling technique made it possible to obtain more detailed results on the sources affecting the area compared to a classical PMF analysis. PMID:24488520

  9. Source apportionment of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in ambient air of an industrial region in Turkey

    NASA Astrophysics Data System (ADS)

    Aydin, Yagmur Meltem; Kara, Melik; Dumanoglu, Yetkin; Odabasi, Mustafa; Elbir, Tolga

    2014-11-01

    Source apportionment is generally applied to a time series of data collected at a single site. However, in a complex airshed containing several different sources, it may be helpful to collect samples from multiple sites to ensure that some of them have low contributions from specific sources, thus the boundaries can be properly defined. Ambient air polycyclic aromatic hydrocarbon (PAH) and polychlorinated biphenyls (PCB) samples (n = 160) were collected at 40 sites during four seasons (summer, fall, winter, and spring) between July 2009 and April 2010 in the heavily industrialized Aliaga region in Turkey to investigate their spatial, seasonal variations and to identify possible PAH and PCB sources. The newest version of EPA PMF (V5.0) having the capability of handling multiple site data was used for source apportionment. Five PAH sources were identified as biomass and coal combustion, iron-steel production, unburned crude oil and petroleum products, and diesel and gasoline exhaust emissions with contributions of 40, 27, 27, 3, and 3%, respectively. The sources of PCBs were identified as iron-steel production (consisting of steel-making and ship breaking activities), coal and wood combustion, and evaporative emissions from technical PCB mixtures with contributions of 57, 31, and 12%, respectively.

  10. Sediment PAH source apportionment in the Liaohe River using the ME2 approach: A comparison to the PMF model.

    PubMed

    Xu, Jian; Peng, Xing; Guo, Chang-Sheng; Xu, Jiao; Lin, Hai-Xia; Shi, Guo-Liang; Lv, Jia-Pei; Zhang, Yuan; Feng, Yin-Chang; Tysklind, Mats

    2016-05-15

    Environmental contaminant source apportionment is essential for pollution management and control. This study analysed surface sediment samples for 16 priority polycyclic aromatic hydrocarbons (PAHs). PAH sources were identified by two receptor models, which included positive matrix factorization (PMF) and multilinear engine 2 (ME2). Three PAH sources in the Liaohe River sediments were identified by PMF, including traffic, coke oven and coal combustion. The ME2 model apportioned one additional source. The two models yielded excellent correlation coefficients between the measured and predicted PAH concentrations. Traffic emission was the primary PAH source associated with the Liaohe River sediments, with estimated PMF contributions of 58% in May and 63% in September. Coke oven (19%-25%) and coal combustion (13%-18%) were the other two major PAH sources. For ME2, gasoline and diesel were separated: accounted for 14% in May and 16% in September; and 53% in May and 48% in September. This study marks the first application of the ME2 model to study sediment contaminant source apportionment. The methodology can potentially be applied to other aquatic environment contaminants. PMID:26925728

  11. Successful application of lead isotopes in source apportionment, legal proceedings, remediation and monitoring.

    PubMed

    Gulson, Brian; Korsch, Michael; Winchester, Wayne; Devenish, Matthew; Hobbs, Thad; Main, Cleve; Smith, Gerard; Rosman, Kevin; Howearth, Lynette; Burn-Nunes, Laurie; Seow, Jimmy; Oxford, Cameron; Yun, Gracie; Gillam, Lindsay; Crisp, Michelle

    2012-01-01

    In late 2006, the seaside community in Esperance Western Australia was alerted to thousands of native bird species dying. The source of the lead (Pb) was determined by Pb isotopes to derive from the handling of Pb carbonate concentrate through the Port, which began in July 2005. Concern was expressed for the impact of this on the community. Our objectives were to employ Pb isotope ratios to evaluate the source of Pb in environmental samples for use in legal proceedings, and for use in remediation and monitoring. Isotope measurements were undertaken of bird livers, plants, drinking water, soil, harbour sediments, air, bulk ceiling dust, gutter sludge, surface swabs and blood. The unique lead isotopic signature of the contaminating Pb carbonate enabled diagnostic apportionment of lead in samples. Apart from some soil and water samples, the proportion of contaminating Pb was >95% in the environmental samples. Lead isotopes were critical in resolving legal proceedings, are being used in the remediation of premises, were used in monitoring of workers involved in the decontamination of the storage facility, and monitoring transport of the concentrate through another port facility. Air samples show the continued presence of contaminant Pb, more than one year after shipping of concentrate ceased, probably arising from dust resuspension. Brief details of the comprehensive testing and cleanup of the Esperance community are provided along with the role of the Community. Lead isotopic analyses can provide significant benefits to regulatory agencies, interested parties, and the community where the signature is able to be characterised with a high degree of certainty. PMID:21925655

  12. Source apportionment of elevated wintertime PAHs by compound-specific radiocarbon analysis

    NASA Astrophysics Data System (ADS)

    Sheesley, R. J.; Kruså, M.; Krecl, P.; Johansson, C.; Gustafsson, Ã.-.

    2008-12-01

    Natural abundance radiocarbon analysis facilitates distinct source apportionment between contemporary biomass/biofuel (14C "alive") versus fossil fuel (14C "dead") combustion. Here, the first compound-specific radiocarbon analysis (CSRA) of atmospheric polycylic aromatic hydrocarbons (PAHs) was demonstrated for a set of samples collected in Lycksele, Sweden a small town with frequent episodes of severe atmospheric pollution in the winter. Renewed interest in residential wood combustion means than this type of seasonal pollution is of increasing concern in many areas. Five individual/paired PAH isolates from three pooled fortnight-long filter collections were analyzed by CSRA: phenanthrene, fluoranthene, pyrene, benzo[b+k]fluoranthene and indeno[cd]pyrene plus benzo[ghi]perylene; phenanthrene was the only compound also analyzed in the gas phase. The measured Δ14C for PAHs spanned from -138.3‰ to 58.0‰. A simple isotopic mass balance model was applied to estimate the fraction biomass (fbiomass) contribution that was constrained to a range of 71% for indeno[cd]pyrene+benzo[ghi]perylene to 87% for the gas phase phenanthrene and particulate fluoranthene, respectively. Indeno[cd]pyrene plus benzo[ghi]perylene, known to be enhanced in gasoline-powered motor vehicle exhaust compared to diesel exhaust, had the lowest contribution of biomass combustion of the measured PAHs by 9%. The total organic carbon (TOC, defined as carbon remaining after removal of inorganic carbon) fbiomass was estimated to be 77%, which falls within the range for PAHs. This CSRA data of atmospheric PAHs demonstrate the non-uniformity of biomass combustion contribution to different PAHs even in a location with limited local emission sources and illustrates that regulatory efforts would not evenly reduce all PAHs.

  13. The 2013 severe haze over the southern Hebei, China: model evaluation, source apportionment, and policy implications

    NASA Astrophysics Data System (ADS)

    Wang, L. T.; Wei, Z.; Yang, J.; Zhang, Y.; Zhang, F. F.; Su, J.; Meng, C. C.; Zhang, Q.

    2013-11-01

    Extremely severe and persistent haze occurred in January 2013 over the eastern and northern China. The record-breaking high concentrations of fine particulate matter (PM2.5) of more than 700 μg m-3 on hourly average and the persistence of the episodes have raised widespread, considerable public concerns. During that period, seven of the top ten polluted cities in China were within Hebei Province. The three cities in southern Hebei, Shijiazhuang, Xingtai, and Handan, have been listed as the top three polluted cities according to the statistics for the first half year of 2013. In this study, the Mesoscale Modeling System Generation 5 (MM5) and the Models-3/Community Multiscale Air Quality (CMAQ) modeling system are applied to simulate the 2013 severe winter regional hazes in East Asia and the northern China at horizontal grid resolutions of 36 and 12 km, respectively, using the Multi-resolution Emission Inventory of China (MEIC). The source contributions of major source regions and sectors to PM2.5 concentrations in the three most-polluted cities in southern Hebei are quantified aiming at the understanding of the sources of the severe haze pollution in this region, and the results are compared with December 2007, the haziest month in 2001-2010. Model evaluation against meteorological and air quality observations indicates an overall acceptable performance and the model tends to underpredict PM2.5 and coarse particulate matter (PM10) concentrations during the extremely severe polluted episodes. The MEIC inventory is proved to be a good estimation in terms of total emissions of cities but uncertainties exist in the spatial allocations of emissions into fine grid resolutions within cities. The source apportionment shows that emissions from the northern Hebei and the Beijing-Tianjin city cluster are two major regional contributors to the pollution in January 2013 in Shijiazhuang, comparing with those from Shanxi and the northern Hebei for December 2007. For Xingtai and

  14. The 2013 severe haze over southern Hebei, China: model evaluation, source apportionment, and policy implications

    NASA Astrophysics Data System (ADS)

    Wang, L. T.; Wei, Z.; Yang, J.; Zhang, Y.; Zhang, F. F.; Su, J.; Meng, C. C.; Zhang, Q.

    2014-03-01

    Extremely severe and persistent haze occurred in January 2013 over eastern and northern China. The record-breaking high concentrations of fine particulate matter (PM2.5) of more than 700 μg m-3 on hourly average and the persistence of the episodes have raised widespread, considerable public concerns. During that period, 7 of the top 10 polluted cities in China were within the Hebei Province. The three cities in southern Hebei (Shijiazhuang, Xingtai, and Handan) have been listed as the top three polluted cities according to the statistics for the first half of the year 2013. In this study, the Mesoscale Modeling System Generation 5 (MM5) and the Models-3/Community Multiscale Air Quality (CMAQ) modeling system are applied to simulate the 2013 severe winter regional hazes in East Asia and northern China at horizontal grid resolutions of 36 and 12 km, respectively, using the Multi-resolution Emission Inventory for China (MEIC). The source contributions of major source regions and sectors to PM2.5 concentrations in the three most polluted cities in southern Hebei are quantified by aiming at the understanding of the sources of the severe haze pollution in this region, and the results are compared with December 2007, the haziest month in the period 2001-2010. Model evaluation against meteorological and air quality observations indicates an overall acceptable performance and the model tends to underpredict PM2.5 and coarse particulate matter (PM10) concentrations during the extremely polluted episodes. The MEIC inventory is proven to be a good estimation in terms of total emissions of cities but uncertainties exist in the spatial allocations of emissions into fine grid resolutions within cities. The source apportionment shows that emissions from northern Hebei and the Beijing-Tianjin city cluster are two major regional contributors to the pollution in January 2013 in Shijiazhuang, compared with those from Shanxi and northern Hebei for December 2007. For Xingtai and Handan

  15. Estimation of source apportionment and potential source locations of PM 2.5 at a west coastal IMPROVE site

    NASA Astrophysics Data System (ADS)

    Hwang, InJo; Hopke, Philip K.

    Particle composition data for PM 2.5 samples collected at Kalmiopsis Interagency Monitoring of Protected Visual Environments (IMPROVE) site in southwestern Oregon from March 2000 to May 2004 were analyzed to provide source identification and apportionment. A total of 493 samples were collected and 32 species were analyzed by particle induced X-ray emission, proton elastic scattering analysis, photon-induced X-ray fluorescence, ion chromatography, and thermal optical reflectance methods. Positive matrix factorization (PMF) was used to estimate the source profiles and their mass contributions. The PMF modeling identified nine sources. In the Kalmiopsis site, the average mass was apportioned to wood/field burning (38.4%), secondary sulfate (26.9%), airborne soil including Asian dust (8.6 %), secondary nitrate (7.6%), fresh sea salt (5.8%), OP-rich sulfate (4.9%), aged sea salt (4.5 %), gasoline vehicle (1.9%), and diesel emission (1.4%). The potential source contribution function (PSCF) was then used to help identify likely locations of the regional sources of pollution. The PSCF map for wood/field burning indicates there is a major potential source area in the Siskiyou County and eastern Oregon. The potential source locations for secondary sulfate are found in western Washington, northwestern Oregon, and the near shore Pacific Ocean where there are extensive shipping lanes. It was not possible to extract a profile directly attributable to ship emissions, but indications of their influence are seen in the secondary sulfate and aged sea salt compositions.

  16. Winter-time size distribution and source apportionment of total suspended particulate matter and associated metals in Delhi

    NASA Astrophysics Data System (ADS)

    Srivastava, Arun; Gupta, Sandeep; Jain, V. K.

    2009-03-01

    A study of the winter time size distribution and source apportionment of total suspended particulate matter (TSPM) and associated heavy metal concentrations have been carried out for the city of Delhi. This study is important from the point of view of implementation of compressed natural gas (CNG) as alternate of diesel fuel in the public transport system in 2001 to reduce the pollution level. TSPM were collected using a five-stage cascade impactor at six sites in the winters of 2005-06. The results of size distribution indicate that a major portion (~ 40%) of TSPM concentration is in the form of PM0.7 (< 0.7 μm). Similar trends were observed with most of the heavy metals associated with various size fractions of TSPM. A very good correlation between coarse and fine size fraction of TSPM was observed. It was also observed that the metals associated with coarse particles have more chances of correlation with other metals; rather they are associated with fine particles. Source apportionment was carried out separately in coarse and fine size modes of TSPM by Chemical Mass Balance Receptor Model (CMB8) as well as by Principle Component Analysis (PCA) of SPSS. Source apportionment by PCA reveals that there are two major sources (possibly vehicular and crustal re-suspension) in both coarse and fine size fractions. Results obtained by CMB8 show the dominance of vehicular pollutants and crustal dust in fine and coarse size mode respectively. Noticeably the dominance of vehicular pollutants are now confined to fine size only whilst during pre CNG era it dominated both coarse and fine size mode. An increase of 42.5, 44.4, 48.2, 38.6 and 38.9% in the concentrations of TSPM, PM10.9, coarse particles, fine particles and lead respectively was observed during pre (2001) to post CNG (2005-06) period.

  17. Spatial distribution, potential risk assessment, and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in sediments of Lake Chaohu, China.

    PubMed

    Li, Chaocan; Huo, Shouliang; Yu, Zhiqiang; Xi, Beidou; Zeng, Xiangying; Wu, Fengchang

    2014-10-01

    Twenty-nine sediment samples were collected from Lake Chaohu, a shallow eutrophic lake in Eastern China, and were analyzed for 15 priority polycyclic aromatic hydrocarbons (PAHs) to determine the spatial distribution and exposure risks of PAHs. Three receptor models, the principal component analysis-multiple linear regression (PCA-MLR) model, the positive matrix factorization (PMF) model, and the Unmix model, were used in combination with the PAHs diagnostic ratios to investigate the potential source apportionment of PAHs. A clear gradient in the spatial distribution and the potential toxicity of PAHs was observed from west to east in the sediments of Lake Chaohu. ∑15PAH concentrations and the TEQ were in the range of 80.82-30 365.01 ng g(-1) d.w. and 40.77-614.03, respectively. The highest values of the aforementioned variables were attributed to urban-industrial pollution sources in the west lake region, and the levels decreased away from the river inlets. The three different models yielded excellent correlation coefficients between the predicted and measured levels of the 15 PAH compounds. Similarly, source apportionment results were derived from the three receptor models and the PAH diagnostic ratios, suggesting that the highest contribution to the PAHs was from coal combustion and wood combustion, followed by vehicular emissions. The PMF model yielded the following contributions to the PAHs from gasoline combustion, diesel combustion, unburned petroleum emissions, and wood combustion: 34.49, 24.61, 16.11, 13.01, and 11.78 %, respectively. The PMF model produced more detailed source apportionment results for the PAHs than the PCA-MLR and Unmix models. PMID:24920262

  18. Characteristics and source apportionment of organic matter in PM(2.5) from cities in different climatic zones of China

    NASA Astrophysics Data System (ADS)

    Feng, Jialiang

    For the first time, the dependency of the characteristics of organic matter in PM2.5 on geographical and climatic zones in three metropolitan cities of China was studied. Seasonal samples were collected at suburban and urban sites in Beijing, Shanghai and Guangzhou in 2002 and 2003. To further support the above study, seasonal samples were also collected at Changdao Island, a remote island, in Bohai Sea/Yellow Sea. Concentrations of organic carbon (OC), elemental carbon (EC), water-soluble organic carbon (WSOC), and solvent-extractable organic compounds (SEOC) were analyzed. The characteristics of the n-alkanes, polycyclic aromatic hydrocarbons, n-fatty acids, n-alkanols and molecular markers such as triterpanes were determined and used for source identification. Source apportionment was complemented by Chemical Mass Balance (CMB) modeling using the measured organic species as tracers. The impact of wind speed and wind direction on air quality was studied by back trajectory calculations and analysis. In general, traffic emissions were the largest contributors of OC followed by coal burning, kitchen emissions, vegetative detritus and biomass burning. However, in the space-heating season in Northern China, coal burning was the most important contributor of OC in the suburban areas of Beijing and at Changdao. Beijing had the highest concentration of organic aerosol followed by Guangzhou and Shanghai, while seasonal variation was in reverse order. Dispersion conditions determined by local topographies and meteorology were responsible for this trend. Contrary to common understanding, pollutant concentrations at the suburban sites were higher than the urban sites in all three cities. The main reason was the rapid urbanization of the suburban areas in the immediate vicinity of urban centers since China opened up for economic development, in addition, large numbers of manufacturing plants were relocated from the cities to the countryside in an attempt to clean up the urban

  19. Development of PM2.5 source impact spatial fields using a hybrid source apportionment air quality model

    NASA Astrophysics Data System (ADS)

    Ivey, C. E.; Holmes, H. A.; Hu, Y. T.; Mulholland, J. A.; Russell, A. G.

    2015-07-01

    An integral part of air quality management is knowledge of the impact of pollutant sources on ambient concentrations of particulate matter (PM). There is also a growing desire to directly use source impact estimates in health studies; however, source impacts cannot be directly measured. Several limitations are inherent in most source apportionment methods motivating the development of a novel hybrid approach that is used to estimate source impacts by combining the capabilities of receptor models (RMs) and chemical transport models (CTMs). The hybrid CTM-RM method calculates adjustment factors to refine the CTM-estimated impact of sources at monitoring sites using pollutant species observations and the results of CTM sensitivity analyses, though it does not directly generate spatial source impact fields. The CTM used here is the Community Multiscale Air Quality (CMAQ) model, and the RM approach is based on the chemical mass balance (CMB) model. This work presents a method that utilizes kriging to spatially interpolate source-specific impact adjustment factors to generate revised CTM source impact fields from the CTM-RM method results, and is applied for January 2004 over the continental United States. The kriging step is evaluated using data withholding and by comparing results to data from alternative networks. Data withholding also provides an estimate of method uncertainty. Directly applied (hybrid, HYB) and spatially interpolated (spatial hybrid, SH) hybrid adjustment factors at withheld observation sites had a correlation coefficient of 0.89, a linear regression slope of 0.83 ± 0.02, and an intercept of 0.14 ± 0.02. Refined source contributions reflect current knowledge of PM emissions (e.g., significant differences in biomass burning impact fields). Concentrations of 19 species and total PM2.5 mass were reconstructed for withheld observation sites using HYB and SH adjustment factors. The mean concentrations of total PM2.5 at withheld observation sites were

  20. Source apportionment of ambient particle number concentrations in central Los Angeles using positive matrix factorization (PMF)

    NASA Astrophysics Data System (ADS)

    Sowlat, Mohammad Hossein; Hasheminassab, Sina; Sioutas, Constantinos

    2016-04-01

    In this study, the positive matrix factorization (PMF) receptor model (version 5.0) was used to identify and quantify major sources contributing to particulate matter (PM) number concentrations, using PM number size distributions in the range of 13 nm to 10 µm combined with several auxiliary variables, including black carbon (BC), elemental and organic carbon (EC/OC), PM mass concentrations, gaseous pollutants, meteorological, and traffic counts data, collected for about 9 months between August 2014 and 2015 in central Los Angeles, CA. Several parameters, including particle number and volume size distribution profiles, profiles of auxiliary variables, contributions of different factors in different seasons to the total number concentrations, diurnal variations of each of the resolved factors in the cold and warm phases, weekday/weekend analysis for each of the resolved factors, and correlation between auxiliary variables and the relative contribution of each of the resolved factors, were used to identify PM sources. A six-factor solution was identified as the optimum for the aforementioned input data. The resolved factors comprised nucleation, traffic 1, traffic 2 (with a larger mode diameter than traffic 1 factor), urban background aerosol, secondary aerosol, and soil/road dust. Traffic sources (1 and 2) were the major contributor to PM number concentrations, collectively making up to above 60 % (60.8-68.4 %) of the total number concentrations during the study period. Their contribution was also significantly higher in the cold phase compared to the warm phase. Nucleation was another major factor significantly contributing to the total number concentrations (an overall contribution of 17 %, ranging from 11.7 to 24 %), with a larger contribution during the warm phase than in the cold phase. The other identified factors were urban background aerosol, secondary aerosol, and soil/road dust, with relative contributions of approximately 12 % (7.4-17.1), 2.1 % (1

  1. [Emission strength and source apportionment of volatile organic compounds in Shanghai during 2010 EXPO].

    PubMed

    Wang, Hong-Li; Chen, Chang-Hong; Huang, Hai-Ying; Wang, Qian; Chen, Yi-Ran; Huang, Cheng; Li, Li; Zhang, Gang-Feng; Chen, Ming-Hua; Lou, Sheng-Rong; Qiao, Li-Ping

    2012-12-01

    The emission strength of VOCs was estimated in the study, based on the volatile organic compounds (VOCs) measurement results. Air mass backward trajectories were computed and cluster analysis was done combining with the corresponding air pollution indexes and VOCs concentrations. Source apportionment of VOCs was studied using receptor model. According to this study, VOCs emission in Shanghai per hour resulted in the VOCs concentration increment of (5.98 +/- 3.18) x 10(-9) during 2010 EXPO (from 1st May to 31st October in 2010), which was decreased by about 1 x 10(-9) compared to that in the same period of 2009. Under the control of the air masses roughly from the east (40%), the API was lower than 50. Influenced by the air masses from the northwest, the air quality was the worst with the average API higher than 70. The air masses from the southwest also resulted in bad air quality, with API higher than 60. The air masses originated from the west accounted for 25%, followed by the south and north air mass (20%). The VOCs concentrations were positively related to API in the same air mass, R2 = 0.599. During the 2010 EXPO, the emission related to vehicles including exhaust and gasoline evaporation contributed the largest amount of VOCs, approximately about -40%, followed by industry including industrial processes and coal combustion (30% - 40%), and solvent use and painting (20%). The biogenic emission was also considerable and accounted for 6% of VOCs in summer. PMID:23379136

  2. Background concentrations and source apportionment of polycyclic aromatic hydrocarbons in south-eastern Finland

    NASA Astrophysics Data System (ADS)

    Vestenius, Mika; Leppänen, Sirkka; Anttila, Pia; Kyllönen, Katriina; Hatakka, Juha; Hellén, Heidi; Hyvärinen, Antti-Pekka; Hakola, Hannele

    2011-07-01

    Polycyclic aromatic hydrocarbons (PAH compounds) were measured in the PM 10 fraction [from ambient air] at Virolahti, Finland. The sampling site is located in a rural area in the south-eastern corner of Finland, near the Russian border. Altogether, 51 daily and 85 weekly filter samples were collected in 2007-2008. The yearly average concentration of benzo(a)pyrene at Virolahti in 2007 was 0.21 ng m -3, which is well below the annual target value of 1 ng m -3 set by the European Union. The positive matrix factorization (PMF) method was applied in source apportionment for daily PAH data combined with other pollutant data. A three-factor solution of the PMF analysis with 28 components was chosen. These three factors were identified as long-range transported secondary particles (F1), combustion (F2) and a sea-salt factor (F3). The conditional probability function (CPF) was used to combine wind direction sectors with the PMF factors. In cases F1 and F2, pollutants mainly originated from the south-east, whereas pollutants in F3 came from the south-western sector. PAHs entered into the combustion factor 2 together with SO 2, NO x, black carbon and potassium. This suggests that the PAHs at Virolahti originated from traffic and industrial pollution, as well as biomass burning. Elevated concentrations occurred throughout the winter period and most frequently originated from the south-eastern sector between 90°-135°. This sector includes, among other transboundary areas, the metropolis of St. Petersburg at a distance of 160 km.

  3. Triple-Isotope-Based Source Apportionment of Methane in Waters of the Outer Laptev Sea

    NASA Astrophysics Data System (ADS)

    Steinbach, J.; Holmstrand, H.; Shcherbakova, K.; Kosmach, D.; Sapart, C. J.; Panova, E.; Bruchert, V.; Semiletov, I. P.; Shakhova, N. E.; Gustafsson, O.

    2015-12-01

    The East Siberian Arctic Shelf (ESAS) hosts large methane (CH4) deposits in the form of gas hydrates, gas pockets within subsea permafrost and in deeper reservoirs. For over a decade, annual expeditions have documented methane releases into the water column in large parts of this region. However, there is still insufficient knowledge of which pools are releasing the methane - one important piece of information required for a deeper understanding of the system and towards predicting future releases. A powerful tool for quantifying the relative contribution of releases from different sources is multi-dimensional isotope analysis of CH4 in the water column. Using the full triple isotope characterization (δ13C-CH4, δD-CH4, Δ14C-CH4) allows deconvolution of CH4 sources between thermogenic and biogenic origins and of different reservoir ages.During the SWERUS-C3 expedition in summer 2014 we investigated the distribution of dissolved methane and its isotope signatures in the water column along the outer ESAS and its adjacent slope and ridges. Over 1500 samples for CH4 concentration from high-resolution vertical profiles (up to 12 depths) were analyzed onboard; 900 samples were taken for stable isotopes analysis; and a total of 80 larger water samples were taken at selected locations for Δ14C-CH4 analysis. CH4 was extracted from these samples onboard using custom-built CH4-stripping systems and stored in absorbent traps for further processing and radiocarbon analysis onshore. One focus was to probe CH4 sources in seep areas, identified by a combination of geophysical features in the sediment, observation of bubbles in the water column and measured CH4 profiles. Here we present triple isotope data from inside and outside seep areas of the outer Laptev Sea and source-apportionment for this region. Dissolved methane concentration there reached up to 1400nM. Stable isotopes results in near bottom waters are rather enriched: Initial results show -142 to -133‰ vs SMOW for

  4. Seasonal effect and source apportionment of polycyclic aromatic hydrocarbons in PM2.5

    NASA Astrophysics Data System (ADS)

    Khan, Md Firoz; Latif, Mohd Talib; Lim, Chee Hou; Amil, Norhaniza; Jaafar, Shoffian Amin; Dominick, Doreena; Mohd Nadzir, Mohd Shahrul; Sahani, Mazrura; Tahir, Norhayati Mohd

    2015-04-01

    This study aims to investigate distribution and sources of 16 polycyclic aromatic hydrocarbons (PAHs) bound to fine particulate matter (PM2.5) captured in a semi-urban area in Malaysia during different seasons, and to assess their health risks. PM2.5 samples were collected using a high volume air sampler on quartz filter paper at a flow rate of 1 m3 min-1 for 24 h. PAHs on the filter paper were extracted with dichloromethane (DCM) using an ultrasonic centrifuge solid-phase extraction method and measured by gas chromatography-mass spectroscopy. The results showed that the range of PAHs concentrations in the study period was between 0.21 and 12.08 ng m-3. The concentrations of PAHs were higher during the south-west monsoon (0.21-12.08 ng m-3) compared to the north-east monsoon (0.68-3.80 ng m-3). The high molecular weight (HMW) PAHs (≥5 ring) are significantly prominent (>70%) compared to the low molecular weight (LMW) PAHs (≤4 ring) in PM2.5. The Spearman correlation indicates that the LMW and HMW PAHs correlate strongly among themselves. The diagnostic ratios (DRs) of I[c]P/I[c]P + BgP and B[a]P/B[g]P suggest that the HMW PAHs originated from fuel combustion sources. The source apportionment analysis of PAHs was resolved using DRs-positive matrix factorization (PMF)-multiple linear regression (MLR). The main sources identified were (a) gasoline combustion (65%), (b) diesel and heavy oil combustion (19%) and (c) natural gas and coal burning (15%). The health risk evaluation, by means of the lifetime lung cancer risk (LLCR), showed no potential carcinogenic risk from the airborne BaPeq (which represents total PAHs at the present study area in Malaysia). The seasonal LLCR showed that the carcinogenic risk of total PAHs were two fold higher during south-westerly monsoon compared to north-easterly monsoon.

  5. Chemical Characterization and Source Apportionment of Indoor and Outdoor Fine Particulate Matter (PM2.5) in Retirement Communities of the Los Angeles Basin

    PubMed Central

    Hasheminassab, Sina; Daher, Nancy; Shafer, Martin M.; Schauer, James J.; Delfino, Ralph J.; Sioutas, Constantinos

    2014-01-01

    Concurrent indoor and outdoor measurements of fine particulate matter (PM2.5) were conducted at three retirement homes in the Los Angeles Basin during two separate phases (cold and warm) between 2005 and 2006. Indoor-to-outdoor relationships of PM2.5 chemical constituents were determined and sources of indoor and outdoor PM2.5 were evaluated using a molecular marker-based chemical mass balance (MM-CMB) model. Indoor levels of elemental carbon (EC) along with metals and trace elements were found to be significantly affected by outdoor sources. EC, in particular, displayed very high indoor-to-outdoor (I/O) mass ratios accompanied by strong I/O correlations, illustrating the significant impact of outdoor sources on indoor levels of EC. Similarly, indoor levels of polycyclic aromatic hydrocarbons (PAHs), hopanes, and steranes were strongly correlated with their outdoor components and displayed I/O ratios close to unity. On the other hand, concentrations of n-alkanes and organic acids inside the retirement communities were dominated by indoor sources (e.g. food cooking and consumer products), as indicated by their I/O ratios, which exceeded unity. Source apportionment results revealed that vehicular emissions were the major contributor to both indoor and outdoor PM2.5, accounting for 39 and 46% of total mass, respectively. Moreover, the contribution of vehicular sources to indoor levels was generally comparable to its corresponding outdoor estimate. Other water-insoluble organic matter (other WIOM), which accounts for emissions from uncharacterized primary biogenic sources, displayed a wider range of contributions, varying from 2 to 73% of PM2.5, across all sites and phases of the study. Lastly, higher indoor than outdoor contribution of other water-soluble organic matter (other WSOM) was evident at some of the sites, suggesting the production of secondary aerosols as well as direct emissions from primary sources (including cleaning or other consumer products) at the

  6. HIGHLY TIME-RESOLVED SOURCE APPORTIONMENT TECHNIQUES FOR ORGANIC AEROSOLS USING THE AERODYNE AEROSOL MASS SPECTROMETER

    EPA Science Inventory

    This project had two major components: (1) the development and application of receptor model techniques to AMS OA data, and (2) the field deployment and field data analysis for several new technique...

  7. Source apportionment of PM10 in a North-Western Europe regional urban background site (Lens, France) using Positive Matrix Factorization and including primary biogenic emissions

    NASA Astrophysics Data System (ADS)

    Waked, A.; Favez, O.; Alleman, L. Y.; Piot, C.; Petit, J.-E.; Delaunay, T.; Verlinden, E.; Golly, B.; Besombes, J.-L.; Jaffrezo, J.-L.; Leoz-Garziandia, E.

    2013-10-01

    In this work, the source of ambient particulate matter (PM10) collected over a one year period at an urban background site in Lens (France) were determined and investigated using a~Positive Matrix Factorization receptor model (US EPA PMF v3.0). In addition, a Potential Source Contribution Function (PSCF) was performed by means of the Hysplit v4.9 model to assess prevailing geographical origins of the identified sources. A selective iteration process was followed for the qualification of the more robust and meaningful PMF solution. Components measured and used in the PMF include inorganic and organic species: soluble ionic species, trace elements, elemental carbon (EC), sugars alcohols, sugar anhydride, and organic carbon (OC). The mean PM10 concentration measured from March 2011 to March 2012 was about 21 μg m-3 with typically OM, nitrate and sulfate contributing to most of the mass and accounting respectively for 5.8, 4.5 and 2.3 μg m-3 on a yearly basis. Accordingly, PMF outputs showed that the main emission sources were (in a decreasing order of contribution): secondary inorganic aerosols (28% of the total PM10 mass), aged marine emissions (19%), with probably predominant contribution of shipping activities, biomass burning (13%), mineral dust (13%), primary biogenic emissions (9%), fresh sea salts (8%), primary traffic emissions (6%) and heavy oil combustion (4%). Significant temporal variations were observed for most of the identified sources. In particular, biomass burning emissions were negligible in summer but responsible for about 25% of total PM10 and 50% of total OC at wintertime. Conversely, primary biogenic emissions were found to be negligible in winter but to represent about 20% of total PM10 and 40% of total OC in summer. The latter result calls for more investigations of primary biogenic aerosols using source apportionment studies, which quite usually disregards this type of sources. This study furthermore underlines the major influence of

  8. Source apportionment of PM10 in a north-western Europe regional urban background site (Lens, France) using positive matrix factorization and including primary biogenic emissions

    NASA Astrophysics Data System (ADS)

    Waked, A.; Favez, O.; Alleman, L. Y.; Piot, C.; Petit, J.-E.; Delaunay, T.; Verlinden, E.; Golly, B.; Besombes, J.-L.; Jaffrezo, J.-L.; Leoz-Garziandia, E.

    2014-04-01

    In this work, the source of ambient particulate matter (PM10) collected over a one-year period at an urban background site in Lens (France) was determined and investigated using a positive matrix factorization receptor model (US EPA PMF v3.0). In addition, a potential source contribution function (PSCF) was performed by means of the Hybrid Single-Particle Lagrangian Integrated Trajectory (Hysplit) v4.9 model to assess prevailing geographical origins of the identified sources. A selective iteration process was followed for the qualification of the more robust and meaningful PMF solution. Components measured and used in the PMF included inorganic and organic species: soluble ionic species, trace elements, elemental carbon (EC), sugar alcohols, sugar anhydride, and organic carbon (OC). The mean PM10 concentration measured from March 2011 to March 2012 was about 21 μg m-3 with typically OM, nitrate and sulfate contributing to most of the mass and accounting respectively for 5.8, 4.5 and 2.3 μg m-3 on a yearly basis. Accordingly, PMF outputs showed that the main emission sources were (in decreasing order of contribution) secondary inorganic aerosols (28% of the total PM10 mass), aged marine emissions (19%), with probably predominant contribution of shipping activities, biomass burning (13%), mineral dust (13%), primary biogenic emissions (9%), fresh sea salts (8%), primary traffic emissions (6%) and heavy oil combustion (4%). Significant temporal variations were observed for most of the identified sources. In particular, biomass burning emissions were negligible in summer but responsible for about 25% of total PM10 and 50% of total OC in wintertime. Conversely, primary biogenic emissions were found to be negligible in winter but to represent about 20% of total PM10 and 40% of total OC in summer. The latter result calls for more investigations of primary biogenic aerosols using source apportionment studies, which quite usually disregard this type of source. This study

  9. [Application of ICP-MS and ICP-AES for Studying on Source Apportionment of PM2.5 during Haze Weather in Urban Beijing].

    PubMed

    Chen, Xi; Du, Peng; Guan, Qing; Feng, Xu; Xu, Dong-qun; Lin, Shao-bin

    2015-06-01

    To investigate the characteristics of chemical constitute and pollution sources of aerosol fine particulate matter during haze-fog day in Beijing in winter 2013. The samples of PM2.5 were collected in Beijing from January to February, 2013. The technique of ICP-MS and ICP-AES coupled with procedure of bathing-ultrasonic extraction was applied to determine the concentration of 40 elements in the aerosol samples to analyze the characteristics of elements distribution statistically. The absolute principal factor method was used to apportion the pollution sources of PM2.5 during the haze weather in Beijing city in winter 2013. The results showed that during the period of sampling, the volume concentration of Li, Mn, Pb, S etc. obeyed normal distribution approximately, and according to National Ambient Air Quality Standard issued by Ministry of Environmental Protection of the People's Republic of China, the geometric mean concentration of As was twice the annual limit of standard reference, while Pb of some aerosol samples beyond the annual limit of standard reference respectively. The mass fraction of Fe, Zn, Pb, Ti accounted for over 0.1%, while that of Mn, Cu, As, Se etc. 0.01%. These elements were primary inorganic pollutants, and especially the hazards and sources of As and Pb should be concerned. There were 6 main pollution sources were chosen by the factor analysis method, including industrial dust and human beings activities, biomass combustion and building dust, soil and sand dusts, fossil fuel, electronic waste and metal smelting, with the variance contribution rate of 40.3%, 27.0%, 9.1%, 4.9%, 4.8% and 4.6% respectively. ICP-MS and ICP-AES can be applied to analyzing multi-elements in PM2.5 accurately and quickly to facilitate source apportionment, and it indicated that the relevant pollution sources should be considered and the effect of regional transferring of haze pollution sources should be taken into account, and specific measures should be taken for

  10. Source apportionment of urban particulate aliphatic and polynuclear aromatic hydrocarbons (PAHs) using multivariate methods.

    PubMed

    Kavouras, I G; Koutrakis, P; Tsapakis, M; Lagoudaki, E; Stephanou, E G; Von Baer, D; Oyola, P

    2001-06-01

    Samples of organic aerosol were collected in Santiago de Chile. An activated-charcoal diffusion denuder was used to strip out organic vapors prior to particle collection. Both polynuclear aromatic hydrocarbons (PAHs) and aliphatic hydrocarbons were determined using gas chromatography/mass spectrometry (GC/MS). Organic particle sources were resolved using both concentration diagnostic ratios and multivariate methods such as hierarchical cluster analysis (HCA) and factor analysis (FA). Four factors were identified based on the loadings of PAHs and n-alkanes and were attributed to the following sources: (1) high-temperature combustion of fuels; (2) fugitive emissions from oil residues; (3) biogenic sources; and (4) unburned fuels. Multilinear regression (MLR) analysis was used to determine emission profiles and contributions of the sources. The reconstructed concentrations of particle phase aliphatic and polynuclear aromatic hydrocarbons were in good agreement (R2 > 0.70) with those measured in Santiago de Chile. PMID:11414034

  11. Source apportionment of particulate matter in a South Asian Mega City: A case study of Karachi

    NASA Astrophysics Data System (ADS)

    Shahid, imran

    2016-04-01

    PM2.5 and PM10-2.5. In order to make air quality better and risk free in South Asian cities a comprehensive and integrated regional effort is required that include continuous air quality monitoring, source apportionment and implementation of regional air quality policies.

  12. Characterization and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in Sediments from the Bohai Sea, China

    NASA Astrophysics Data System (ADS)

    Liu, Jihua; Hu, Ningjing; Shi, Xuefa

    2015-04-01

    Characterization and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in Sediments from the Bohai Sea, China Liu Jihua, Hu Ningjing, Shi Xuefa First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China Polycyclic aromatic hydrocarbons (PAHs) are a class of ubiquitous organic contaminants in the environment. Indeed, 16 PAH compounds have been listed as priority pollutants by the United States Environmental Protection Agency and the European Union because of their potential toxicity to humans and ecosystems. As POPs are released or escape into the environment, their global accumulation in marine sediments generates a complex balance between inputs and outputs. Furthermore, PAHs in coastal sediments can serve as effective tracers of materials transport from land-to-sea (Fang et al., 2009). Hence, investigations of PAHs in sediments can provide useful information for further understanding of environmental processes and material transport. In this study, sixteen polycyclic aromatic hydrocarbons (PAHs) were extracted from a total of 112 surface sediment samples collected across the entire territory of the Bohai Sea. The detectable concentrations of PAHs ranged from 97.2 to 300.7 ng/g across all samples, indicating low contamination levels of PAHs compared with reported values for other coastal sediments in China and developed countries. The highest concentrations were found within three belts in the vicinity of Luan River Estuary-Qinhuangdao Harbor, the Cao River Estuary-Bohai Sea Center, and north of the Yellow River Estuary. The distribution patterns of PAHs and source identification implied that PAH contamination in the Bohai Sea mainly originates from offshore oil exploration, sewage discharge from rivers and shipping activities. Further Principal components analysis (PCA)/multivariate linear regression (MLR) analysis suggested that the contributions of spilled oil products (petrogenic), coal combustion and traffic

  13. Chemical characterization of atmospheric particles and source apportionment in the vicinity of a steelmaking industry.

    PubMed

    Almeida, S M; Lage, J; Fernández, B; Garcia, S; Reis, M A; Chaves, P C

    2015-07-15

    The objective of this work was to provide a chemical characterization of atmospheric particles collected in the vicinity of a steelmaking industry and to identify the sources that affect PM10 levels. A total of 94 PM samples were collected in two sampling campaigns that occurred in February and June/July of 2011. PM2.5 and PM2.5-10 were analyzed for a total of 22 elements by Instrumental Neutron Activation Analysis and Particle Induced X-ray Emission. The concentrations of water soluble ions in PM10 were measured by Ion Chromatography and Indophenol-Blue Spectrophotometry. Positive Matrix Factorization receptor model was used to identify sources of particulate matter and to determine their mass contribution to PM10. Seven main groups of sources were identified: marine aerosol identified by Na and Cl (22%), steelmaking and sinter plant represented by As, Cr, Cu, Fe, Ni, Mn, Pb, Sb and Zn (11%), sinter plant stack identified by NH4(+), K and Pb (12%), an unidentified Br source (1.8%), secondary aerosol from coke making and blast furnace (19%), fugitive emissions from the handling of raw material, sinter plant and vehicles dust resuspension identified by Al, Ca, La, Si, Ti and V (14%) and sinter plant and blast furnace associated essentially with Fe and Mn (21%). PMID:25864153

  14. Source apportionment of ambient fine particle size distribution using positive matrix factorization in Erfurt, Germany

    PubMed Central

    Yue, Wei; Stölzel, Matthias; Cyrys, Josef; Pitz, Mike; Heinrich, Joachim; Kreyling, Wolfgang G.; Wichmann, H.-Erich; Peters, Annette; Wang, Sheng; Hopke, Philip K.

    2008-01-01

    Particle size distribution data collected between September 1997 and August 2001 in Erfurt, Germany were used to investigate the sources of ambient particulate matter by positive matrix factorization (PMF). A total of 29,313 hourly averaged particle size distribution measurements covering the size range of 0.01 to 3.0 μm were included in the analysis. The particle number concentrations (cm−3) for the 9 channels in the ultrafine range, and mass concentrations (ng m−3) for the 41 size bins in the accumulation mode and particle up to 3 μm in aerodynamic diameter were used in the PMF. The analysis was performed separately for each season. Additional analyses were performed including calculations of the correlations of factor contributions with gaseous pollutants (O3, NO, NO2, CO and SO2) and particle composition data (sulfate, organic carbon and elemental carbon), estimating the contributions of each factor to the total number and mass concentration, identifying the directional locations of the sources using the conditional probability function, and examining the diurnal patterns of factor scores. These results were used to assist in the interpretation of the factors. Five factors representing particles from airborne soil, ultrafine particles from local traffic, secondary aerosols from local fuel combustion, particles from remote traffic sources, and secondary aerosols from multiple sources were identified in all seasons. PMID:18433834

  15. Simultaneous monitoring and compositions analysis of PM1 and PM2.5 in Shanghai: Implications for characterization of haze pollution and source apportionment.

    PubMed

    Qiao, Ting; Zhao, Mengfei; Xiu, Guangli; Yu, Jianzhen

    2016-07-01

    A year-long simultaneous observation of PM1 and PM2.5 were conducted at ECUST campus in Shanghai, the compositions were analyzed and compared. Results showed that PM2.5 was dominated by PM1 on clear days while the contribution of PM1-2.5 to PM2.5 increased on haze days, indicating that PM2.5 should be given priority to characterize or predict haze pollution. On haze days, accumulation of organic carbon (OC), elemental carbon (EC) and primary organic carbon (POC) in PM1-2.5 was faster than that in PM1. Humic-like substances carbon (Hulis-C) in both PM2.5 and PM1 formed faster than water soluble organic carbon (WSOC) on haze days, hence Hulis-C/WSOC increased with the intensification of haze pollution. In terms of water soluble ions, NO3(-)/SO4(2-) in PM1 increased with the aggravation of haze pollution, implying that mobile sources dominated on haze days, so is nitrogen oxidation ratio (NOR). Liquid water content (LWC) in both PM1 and PM2.5 had positive correlations with relative humidity (RH) but negative correlations with visibility, implying that hygroscopic growth might be a factor for visibility impairment, especially LWC in PM1. By comparison with multi-linear equations of LWC in PM1 and PM2.5, NO3(-) exerted a higher influence on hygroscopicity of PM1 than PM2.5, while RH, WSOC, SO4(2-) and NH4(+) had higher effects on PM2.5, especially WSOC. Source apportionment of PM2.5 was also investigated to provide reference for policy making. Cluster analysis by HYSPLIT (HYbrid Single Particle Lagrangian Integrated Trajectory) model showed that PM2.5 originated from marine aerosols, middle-scale transportation and large-scale transportation. Furthermore, PM2.5 on haze days was dominated by middle-scale transportation. In line with source apportionment by positive matrix factorization (PMF) model, PM2.5 was attributed to secondary inorganics, aged sea salt, combustion emissions, hygroscopic growth and secondary organics. Secondary formation was the principle source of

  16. Fine particulate matter and visibility in the Lake Tahoe Basin: chemical characterization, trends, and source apportionment.

    PubMed

    Green, Mark C; Chen, L W Antony; DuBois, David W; Molenar, John V

    2012-08-01

    Speciated PM2.5 (particulate matter with an aerodynamic diameteraerosol dominated reconstructedfine mass at both sites, with 58% at Bliss State Park (BLIS) and 68% at South Lake Tahoe (SOLA). Fine mass at SOLA is 2.5 times that at BLIS, mainly due to enhanced organic and elemental carbon (OC and EC). SOLA experiences a winter peak in PM25 mainly due to OC and EC from residential wood combustion, whereas BLIS experiences a summer peak in PM2.5 mainly due to OC and ECfrom wildfires. Carbonaceous aerosol dominates visibility impairment, causing about 1/2 the reconstructed aerosol light extinction at BLIS and 70% at SOLA. Trend analysis (1990-2009) showed statistically significant decreases in aerosol extinction at BLIS on 20% best and 60% middle visibility days and statistically insignificant upward trends on 20% worst days. SOLA (1990-2003) showed statistically significant decreases in aerosol extinction for all day categories, driven by decreasing OC and EC. From the regional haze rule baseline period of 2000-2004 until 2005-2009, BLIS saw 20% best days improving and 20% worst days getting worse due to increased wildfire effects. Receptor modeling was performed using positive matrix factorization (PMF) and chemical mass balance (CMB). It confirmed that (1) biomass burning dominanted PM25 sources at both sites with increasing importance over time; (2) low combustion efficiency burning accounts for most of the biomass burning contribution; (3) road dust and traffic contributions were much higher at SOLA than at BLIS; and (4) industrial combustion and salting were minor sources. PMID:22916443

  17. Concentration levels and source apportionment of ultrafine particles in road microenvironments

    NASA Astrophysics Data System (ADS)

    Argyropoulos, G.; Samara, C.; Voutsa, D.; Kouras, A.; Manoli, E.; Voliotis, A.; Tsakis, A.; Chasapidis, L.; Konstandopoulos, A.; Eleftheriadis, K.

    2016-03-01

    A mobile laboratory unit (MOBILAB) with on-board instrumentation (Scanning Mobility Particle Sizer, SMPS; Ambient NOx analyzer) was used to measure size-resolved particle number concentrations (PNCs) of quasi-ultrafine particles (UFPs, 9-372 nm), along with NOx, in road microenvironments. On-road measurements were carried out in and around a large Greek urban agglomeration, the Thessaloniki Metropolitan Area (TMA). Two 2-week measurement campaigns were conducted during the warm period of 2011 and the cold period of 2012. During each sampling campaign, MOBILAB was driven through a 5-day inner-city route and a second 5-day external route covering in total a wide range of districts (urban, urban background, industrial and residential), and road types (major and minor urban roads, freeways, arterial and interurban roads). All routes were conducted during working days, in morning and in afternoon hours under real-world traffic conditions. Spatial classification of MOBILAB measurements involved the assignment of measurement points to location bins defined by the aspect ratio of adjacent urban street canyons (USCs). Source apportionment was further carried out, by applying Positive Matrix Factorization (PMF) to particle size distribution data. Apportioned PMF factors were interpreted, by employing a two-step methodology, which involved (a) statistical association of PMF factor contributions with 12 h air-mass back-trajectories ending at the TMA during MOBILAB measurements, and (b) Multiple Linear Regression (MLR) using PMF factor contributions as the dependent variables, while relative humidity, solar radiation flux, and vehicle speed were used as the independent variables. The applied data analysis showed that low-speed cruise and high-load engine operation modes are the two dominant sources of UFPs in most of the road microenvironments in the TMA, with significant contributions from background photochemical processes during the warm period, explaining the reversed

  18. Source apportionment of particulate matter in Chinese megacities: the implication for emission control strategies

    NASA Astrophysics Data System (ADS)

    Huang, Ru-Jin; Elser, Miriam; Wang, Qiyuan Wang; Bozzetti, Carlo; Wolf, Robert; Wang, Yichen; Ni, Haiyan; Wang, Meng; Ho, Kin-Fai; Han, Yongming; Dällenbach, Kaspar; Canonaco, Francesco; Slowik, Jay; El Haddad, Imad; Baltensperger, Urs; Cao, Junji; Prévôt, André S. H.

    2015-04-01

    The rapid industrialization and urbanization in developing countries has led to an increase in air pollution, along a similar trajectory to that previously experienced by the developed nations. In China, particulate pollution is a serious environmental problem that is influencing air quality, regional and global climates, and human health. A quantitative understanding of these effects has proven extremely challenging due to spatial and temporal variability in the sources of aerosols and their precursors, the complexity of particle composition, and uncertainties associated with the atmospheric aging of existing particles (Pöschl 2005; Hallquist et al., 2009; Huang et al., 2014). Nowadays the average PM2.5 concentrations in China are approximately one to two orders of magnitude higher than those observed in urban areas in the US and European countries (Cao 2012). This has forced the Chinese government to announce its first national environmental standard for PM2.5 in 2012 and to make highly ambitious plans for emission control. The Chinese aim to reduce the PM2.5 concentrations by up to 25% of the 2012 levels by 2017, backed by 277 billion investments from the central government. To achieve this ambitious aim, a better understanding of the aerosol composition, sources, and atmospheric processing is required. In this study, we present the results from intensive field measurement campaigns carried out in Chinese megacities in 2013/2014. The sources of PM2.5 and the organic aerosol (OA) were investigated by applying the multi-linear engine (ME-2) receptor model (Canonaco et al., 2013) to a comprehensive dataset. Primary sources including vehicle emissions, biomass burning, coal burning, and dust-related emissions were identified and quantified. The contributions from secondary aerosol formation processes to total PM2.5 mass and OA mass were evaluated. Detailed results will be presented and discussed. References Cao, J. J. (2012) J. Earth Environ., 3, 1030

  19. Source Apportionment of PM10 by Positive Matrix Factorization in Urban Area of Mumbai, India

    PubMed Central

    Gupta, Indrani; Salunkhe, Abhaysinh; Kumar, Rakesh

    2012-01-01

    Particulate Matter (PM10) has been one of the main air pollutants exceeding the ambient standards in most of the major cities in India. During last few years, receptor models such as Chemical Mass Balance, Positive Matrix Factorization (PMF), PCA–APCS and UNMIX have been used to provide solutions to the source identification and contributions which are accepted for developing effective and efficient air quality management plans. Each site poses different complexities while resolving PM10 contributions. This paper reports the variability of four sites within Mumbai city using PMF. Industrial area of Mahul showed sources such as residual oil combustion and paved road dust (27%), traffic (20%), coal fired boiler (17%), nitrate (15%). Residential area of Khar showed sources such as residual oil combustion and construction (25%), motor vehicles (23%), marine aerosol and nitrate (19%), paved road dust (18%) compared to construction and natural dust (27%), motor vehicles and smelting work (25%), nitrate (16%) and biomass burning and paved road dust (15%) in Dharavi, a low income slum residential area. The major contributors of PM10 at Colaba were marine aerosol, wood burning and ammonium sulphate (24%), motor vehicles and smelting work (22%), Natural soil (19%), nitrate and oil burning (18%). PMID:22645437

  20. Source apportionment of PM10 at a small industrial area using Positive Matrix Factorization

    NASA Astrophysics Data System (ADS)

    Lim, Jong-Myoung; Lee, Jin-Hong; Moon, Jong-Hwa; Chung, Yong-Sam; Kim, Ki-Hyun

    2010-01-01

    In this study, PM10-bound concentrations of 28 trace metals and 3 ionic components were measured from samples collected at Daejeon Industrial Complexes I and II, Korea from April 2000 to December 2002. Positive matrix factorization (PMF) and conditional probability function (CPF) were applied to these PM data sets to identify the diverse sources in the industrial area. A total of nine source types were identified to be important which include: secondary aerosol, cement/construction, soil dust, road dust, vehicle exhaust, incineration/Pb-related industry, metal smelting, fossil fuel combustion, and field burning. Results of our study suggest that there are competing relationships between anthropogenic and natural source processes in this industrial area.

  1. AIRUSE-LIFE+: a harmonized PM speciation and source apportionment in 5 Southern European cities

    NASA Astrophysics Data System (ADS)

    Amato, F.; Alastuey, A.; Karanasiou, A.; Lucarelli, F.; Nava, S.; Calzolai, G.; Severi, M.; Becagli, S.; Gianelle, V. L.; Colombi, C.; Alves, C.; Custódio, D.; Nunes, T.; Cerqueira, M.; Pio, C.; Eleftheriadis, K.; Diapouli, E.; Reche, C.; Minguillón, M. C.; Manousakas, M.; Maggos, T.; Vratolis, S.; Harrison, R. M.; Querol, X.

    2015-09-01

    The AIRUSE-LIFE+ project aims at characterising similarities and heterogeneities in PM sources and contributions in urban areas from the Southern Europe. Once the main PMx sources are identified, AIRUSE aims at developing and testing the efficiency of specific and non-specific measures to improve urban air quality. This article reports the results of the source apportionment of PM10 and PM2.5 conducted at three urban background sites (Barcelona, Florence and Milan, BCN-UB, FI-UB, MLN-UB) one sub-urban background site (Athens, ATH-SUB) and one traffic site (Porto, POR-TR). After collecting 1047 PM10 and 1116 PM2.5 24 h samples from January 2013 to February 2014 simultaneously at the 5 cities, these were analysed for the contents of OC, EC, anions, cations, major and trace elements and levoglucosan. The USEPA PMF5 receptor model was applied to these datasets in a harmonised way for each city. The sum of vehicle exhaust and non-exhaust contributes within 3.9-10.8 μg m-3 (16-32 %) to PM10 and 2.3-9.4 μg m-3 (15-36 %) to PM2.5, although a fraction of secondary nitrate is also traffic-related but could not be estimated. Important contributions arise from secondary particles (nitrate, sulphate and organics) in PM2.5 (37-82 %) but also in PM10 (40-71 %) mostly at background sites, revealing the importance of abating gaseous precursors in designing air quality plans. Biomass burning (BB) contributions vary widely, from 14-24 % of PM10 in POR-TR, MLN-UB and FI-UB, 7 % in ATH-SUB to < 2 % in BCN-UB. In PM2.5, BB is the second most important source in MLN-UB (21 %) and in POR-TR (18 %), the third one in FI-UB (21 %) and ATH-SUB (11 %), but again negligible (< 2 %) in BCN-UB. This large variability among cities is mostly due to the degree of penetration of biomass for residential heating. In Barcelona natural gas is very well supplied across the city and used as fuel in 96 % of homes, while, in other cities, PM levels increase on an annual basis by 1-9 μg m-3 due to this

  2. Atmospheric Aerosol Source-Receptor Relationships: The Role of Coal-Fired Power Plants

    SciTech Connect

    Allen L. Robinson; Spyros N. Pandis; Cliff I. Davidson

    2005-12-01

    This report describes the technical progress made on the Pittsburgh Air Quality Study (PAQS) during the period of March 2005 through August 2005. Significant progress was made this project period on the source characterization, source apportionment, and deterministic modeling activities. This report highlights new data on road dust, vegetative detritus and motor vehicle emissions. For example, the results show significant differences in the composition in urban and rural road dust. A comparison of the organic of the fine particulate matter in the tunnel with the ambient provides clear evidence of the significant contribution of vehicle emissions to ambient PM. The source profiles developed from this work are being used by the source-receptor modeling activities. The report presents results on the spatial distribution of PMF-factors. The results can be grouped into three different categories: regional sources, local sources, or potentially both regional and local sources. Examples of the regional sources are the sulfate and selenium PMF-factors which most likely-represent coal fired power plants. Examples of local sources are the specialty steel and lead factors. There is reasonable correspondence between these apportionments and data from the EPA TRI and AIRS emission inventories. Detailed comparisons between PMCAMx predictions and measurements by the STN and IMPROVE measurements in the Eastern US are presented. Comparisons were made for the major aerosol components and PM{sub 2.5} mass in July 2001, October 2001, January 2002, and April 2002. The results are encouraging with average fraction biases for most species less than 0.25. The improvement of the model performance during the last two years was mainly due to the comparison of the model predictions with the continuous measurements in the Pittsburgh Supersite. Major improvements have included the descriptions: of ammonia emissions (CMU inventory), night time nitrate chemistry, EC emissions and their diurnal

  3. The Denver Aerosol Sources and Health (DASH) Study: Overview and Early Findings

    PubMed Central

    Vedal, S.; Hannigan, M.P.; Dutton, S.J.; Miller, S. L.; Milford, J.B.; Rabinovitch, N.; Kim, S.-Y.; Sheppard, L.

    2012-01-01

    Improved understanding of the sources of air pollution that are most harmful could aid in developing more effective measures for protecting human health. The Denver Aerosol Sources and Health (DASH) study was designed to identify the sources of ambient fine particulate matter (PM2.5) that are most responsible for the adverse health effects of short-term exposure to PM 2.5. Daily 24-hour PM2.5 sampling began in July 2002 at a residential monitoring site in Denver, Colorado, using both Teflon and quartz filter samplers. Sampling is planned to continue through 2008. Chemical speciation is being carried out for mass, inorganic ionic compounds (sulfate, nitrate and ammonium), and carbonaceous components, including elemental carbon, organic carbon, temperature-resolved organic carbon fractions and a large array of organic compounds. In addition, water soluble metals were measured daily for 12 months in 2003. A receptor-based source apportionment approach utilizing positive matrix factorization (PMF) will be used to identify PM 2.5 source contributions for each 24-hour period. Based on a preliminary assessment using synthetic data, the proposed source apportionment should be able to identify many important sources on a daily basis, including secondary ammonium nitrate and ammonium sulfate, diesel vehicle exhaust, road dust, wood combustion and vegetative debris. Meat cooking, gasoline vehicle exhaust and natural gas combustion were more challenging for PMF to accurately identify due to high detection limits for certain organic molecular marker compounds. Measurements of these compounds are being improved and supplemented with additional organic molecular marker compounds. The health study will investigate associations between daily source contributions and an array of health endpoints, including daily mortality and hospitalizations and measures of asthma control in asthmatic children. Findings from the DASH study, in addition to being of interest to policymakers, by

  4. The Denver Aerosol Sources and Health (DASH) study: Overview and early findings

    NASA Astrophysics Data System (ADS)

    Vedal, S.; Hannigan, M. P.; Dutton, S. J.; Miller, S. L.; Milford, J. B.; Rabinovitch, N.; Kim, S.-Y.; Sheppard, L.

    Improved understanding of the sources of air pollution that are most harmful could aid in developing more effective measures for protecting human health. The Denver Aerosol Sources and Health (DASH) study was designed to identify the sources of ambient fine particulate matter (PM 2.5) that are most responsible for the adverse health effects of short-term exposure to PM 2.5. Daily 24-h PM 2.5 sampling began in July 2002 at a residential monitoring site in Denver, Colorado, using both Teflon and quartz filter samplers. Sampling is planned to continue through 2008. Chemical speciation is being carried out for mass, inorganic ionic compounds (sulfate, nitrate and ammonium), and carbonaceous components, including elemental carbon, organic carbon, temperature-resolved organic carbon fractions and a large array of organic compounds. In addition, water-soluble metals were measured daily for 12 months in 2003. A receptor-based source apportionment approach utilizing positive matrix factorization (PMF) will be used to identify PM 2.5 source contributions for each 24-h period. Based on a preliminary assessment using synthetic data, the proposed source apportionment should be able to identify many important sources on a daily basis, including secondary ammonium nitrate and ammonium sulfate, diesel vehicle exhaust, road dust, wood combustion and vegetative debris. Meat cooking, gasoline vehicle exhaust and natural gas combustion were more challenging for PMF to accurately identify due to high detection limits for certain organic molecular marker compounds. Measurements of these compounds are being improved and supplemented with additional organic molecular marker compounds. The health study will investigate associations between daily source contributions and an array of health endpoints, including daily mortality and hospitalizations and measures of asthma control in asthmatic children. Findings from the DASH study, in addition to being of interest to policymakers, by

  5. Occurrence and source apportionment of sulfonamides and their metabolites in Liaodong Bay and the adjacent Liao River basin, North China.

    PubMed

    Jia, Ai; Hu, Jianying; Wu, Xiaoqin; Peng, Hui; Wu, Shimin; Dong, Zhaomin

    2011-06-01

    The presence of antibiotics in the environment is of great concern because of their potential for resistance selection among pathogens. In the present study we investigated the occurrence of 19 sulfonamides, five N-acetylated sulfonamide metabolites, and trimethoprim in the Liao River basin and adjacent Liaodong Bay, China, as well as 10 human/agricultural source samples. Within the 35 river samples, 12 sulfonamides, four acetylated sulfonamides, and trimethoprim were detected, with the dominant being sulfamethoxazole (66.6 ng/L), N-acetylsulfamethoxazole (63.1 ng/L), trimethoprim (29.0 ng/L), sulfadiazine (14.0 ng/L), and sulfamonomethoxine (8.4 ng/L); within the 36 marine samples, 10 chemicals were detected, with the main contributions from sulfamethoxazole (25.2 ng/L) and N-acetylsulfamethoxazole (28.6 ng/L). Sulfamethoxazole (25.9%), N-acetylsulfamethoxazole (46.6%), trimethoprim (22.9%), and sulfapyridine (1.4%) were the main chemicals from human sources, while sulfamonomethoxine, sulfamethazine, sulfaquinoxaline, sulfaguanidine, sulfadiazine, sulfanilamide, and sulfamethoxypyridazine were dominant in the animal husbandry sources, specifically, swine and poultry farms, and sulfamethoxazole (91%) was dominant in the mariculture source. A principal component analysis with multiple linear regression was performed to evaluate the source apportionment of total sulfonamides in Liaodong Bay. It was found that animal husbandry contributed 15.2% of total sulfonamides, while human sources contributed 28.5%, and combined human and mariculture sources contributed 56.3%. In addition, the mariculture contribution was 24.1% of total sulfonamides into the sea based on mass flux estimation. The present study is the first report that the environmental levels of sulfonamide metabolites were comparable to the corresponding parents; therefore, we should pay attention to their environmental occurrence. Source apportionment showed human discharge (60.7%) significantly

  6. A study of control policy in the Pearl River Delta region by using the particulate matter source apportionment method

    NASA Astrophysics Data System (ADS)

    Wu, Dongwei; Fung, Jimmy Chi Hung; Yao, Teng; Lau, Alexis Kai Hon

    2013-09-01

    In recent years, Mainland China, and in particular the industrial hotbed of the Pearl River Delta (PRD) has experienced an increasingly serious problem of high concentrations of airborne particulate matter. Following the tightening-up of China's air quality policies in recent years, and with especially fine particles now added to a new air quality objective, the identification of major source regions and major types of pollutants has become crucial. In this study, the Comprehensive Air Quality Model (CAMx), together with the Particulate Source Apportionment Technology (PSAT) source apportionment method, has been applied to analyze how different emission activities influence PM concentration in the PRD region. By using this method, a detailed source region and emission category contribution matrix is derived for all regions within the Hong Kong/PRD region and source appointment results show that, on average, for different cities super-regional transport and mobile vehicles are the two major fine particle sources, contributing 62% (34.3 μg m-3) and 21% (12.2 μg m-3) of the total figure in December, and 42% (13.1 μg m-3) and 28% (9.7 μg m-3) in April. Meanwhile, over the same period in Hong Kong, in addition to these two factors, marine proved another very significant source of particle pollutant, amounting to 18% of the total figure (4.7 μg m-3). Another important cause of high PM levels has been the transport of fine particles between cities within the PRD region, with three different regions selected for detailed analysis. Results show that for the Hong Kong/PRD region local reduction of mobile sources and collaboration between different areas could have succeeded in alleviating the air pollution problem.

  7. Primary sources of PM2.5 organic aerosol in an industrial Mediterranean city, Marseille

    NASA Astrophysics Data System (ADS)

    El Haddad, I.; Marchand, N.; Wortham, H.; Piot, C.; Besombes, J.-L.; Cozic, J.; Chauvel, C.; Armengaud, A.; Robin, D.; Jaffrezo, J.-L.

    2010-11-01

    Marseille, the most important port of the Mediterranean Sea, represents a challenging case study for source apportionment exercises, combining an active photochemistry and multiple emission sources, including fugitive emissions from industrial sources and shipping. This paper presents a Chemical Mass Balance (CMB) approach based on organic markers and metals to apportion the primary sources of organic aerosol in Marseille, with a special focus on industrial emissions. Overall, the CMB model accounts for the major primary anthropogenic sources including motor vehicles, biomass burning, and the aggregate emissions from three industrial processes (HFO combustion/shipping, coke production and steel manufacturing) as well as some primary biogenic emissions. This source apportionment exercise is well corroborated by 14C measurements. Primary OC estimated by the CMB accounts on average for 22% and is dominated by the vehicular emissions that contribute on average for 17% of OC mass concentration (17% of PM2.5). Even though, industrial emissions contribute for only 2.3% of the total OC (7% of PM2.5), they are associated with ultrafine particles (Dp<80 nm) and high concentrations of Polycyclic Aromatic Hydrocarbons (PAH) and heavy metals such as Pb, Ni and V. On one hand, given that industrial emissions governed key primary markers, their omission would lead to substantial uncertainties in the CMB analysis performed in areas heavily impacted by such sources, hindering accurate estimation of non-industrial primary sources and secondary sources. This result implies that CMB modelling should not be a straightforward exercise and one have to carefully investigate the marker behaviours and trends beforehand, especially in complex environments such as Marseille. On the other hand, being associated with bursts of submicron particles and carcinogenic and mutagenic components such as PAH, these emissions are most likely related with acute health outcomes and should be regulated

  8. Primary sources of PM2.5 organic aerosol in an industrial Mediterranean city, Marseille

    NASA Astrophysics Data System (ADS)

    El Haddad, I.; Marchand, N.; Wortham, H.; Piot, C.; Besombes, J.-L.; Cozic, J.; Chauvel, C.; Armengaud, A.; Robin, D.; Jaffrezo, J.-L.

    2011-03-01

    Marseille, the most important port of the Mediterranean Sea, represents a challenging case study for source apportionment exercises, combining an active photochemistry and multiple emission sources, including fugitive emissions from industrial sources and shipping. This paper presents a Chemical Mass Balance (CMB) approach based on organic markers and metals to apportion the primary sources of organic aerosol in Marseille, with a special focus on industrial emissions. Overall, the CMB model accounts for the major primary anthropogenic sources including motor vehicles, biomass burning and the aggregate emissions from three industrial processes (heavy fuel oil combustion/shipping, coke production and steel manufacturing) as well as some primary biogenic emissions. This source apportionment exercise is well corroborated by 14C measurements. Primary OC estimated by the CMB accounts on average for 22% of total OC and is dominated by the vehicular emissions that contribute on average for 17% of OC mass concentration (vehicular PM contributes for 17% of PM2.5). Even though industrial emissions contribute only 2.3% of the total OC (7% of PM2.5), they are associated with ultrafine particles (Dp<80 nm) and high concentrations of Polycyclic Aromatic Hydrocarbons (PAH) and heavy metals such as Pb, Ni and V. On one hand, given that industrial emissions governed key primary markers, their omission would lead to substantial uncertainties in the CMB analysis performed in areas heavily impacted by such sources, hindering accurate estimation of non-industrial primary sources and secondary sources. On the other hand, being associated with bursts of submicron particles and carcinogenic and mutagenic components such as PAH, these emissions are most likely related with acute ill-health outcomes and should be regulated despite their small contributions to OC. Another important result is the fact that 78% of OC mass cannot be attributed to the major primary sources and, thus, remains un

  9. Source apportionment of particulate matter (PM 2.5) in an urban area using dispersion, receptor and inverse modelling

    NASA Astrophysics Data System (ADS)

    Laupsa, Herdis; Denby, Bruce; Larssen, Steinar; Schaug, Jan

    Air pollution emission inventories are the basis for air quality assessment and management strategies. The quality of the inventories is of great importance since these data are essential for air pollution impact assessments using dispersion models. In this study, the quality of the emission inventory for fine particulates (PM 2.5) is assessed: first, using the calculated source contributions from a receptor model; second, using source apportionment from a dispersion model; and third, by applying a simple inverse modelling technique which utilises multiple linear regression of the dispersion model source contributions together with the observed PM 2.5 concentrations. For the receptor modelling the chemical composition of PM 2.5 filter samples from a measurement campaign performed between January 2004 and April 2005 are analysed. Positive matrix factorisation is applied as the receptor model to detect and quantify the various source contributions. For the same observational period and site, dispersion model calculations using the Air Quality Management system, AirQUIS, are performed. The results identify significant differences between the dispersion and receptor model source apportionment, particularly for wood burning and traffic induced suspension. For wood burning the receptor model calculations are lower, by a factor of 0.54, but for the traffic induced suspension they are higher, by a factor of 7.1. Inverse modelling, based on regression of the dispersion model source contributions and the PM 2.5 concentrations, indicates similar discrepancies in the emissions inventory. In order to assess if the differences found at the one site are generally applicable throughout Oslo, the individual source category emissions are rescaled according to the receptor modelling results. These adjusted PM 2.5 concentrations are compared with measurements at four independent stations to evaluate the updated inventory. Statistical analysis shows improvement in the estimated

  10. Source apportionment of visibility impairment using a three-dimensional source-oriented air quality model.

    PubMed

    Ying, Qi; Mysliwiec, Mitchell; Kleeman, Michael J

    2004-02-15

    A three-dimensional source-oriented Eulerian air quality model is developed that can predict source contributions to the visibility reduction. Particulate matter and precursor gases from 14 different sources (crustal material, paved road dust, diesel engines, meat cooking, noncatalyst-equipped gasoline engines, catalyst-equipped gasoline engines, high-sulfur fuel, sea salt, refrigerant losses, residential production, animals, soil and fertilizer application, other anthropogenic sources, and background sources) are tracked though a mathematical simulation of emission, chemical reaction, gas-to-particle conversion, transport, and deposition. A visibility model based on Mie theory is modified to use the calculated source contributions to airborne particulate matter size and composition as well as gas-phase pollutant concentrations to quantify total source contributions to visibility impairment. The combined air quality-visibility model is applied to predict source contributions to visibility reduction in southern California for a typical air pollution episode (September 23-25, 1996). The model successfully predicts a severe visibility reduction in the eastern portion of the South Coast Air Basin where the average daytime visibility is measured to be less than 10 km. In the relatively clean coastal portion of the domain, the model successfully predicts that the average daytime visibility is greater than 65 km. Transportation-related sources directly account for approximately 50% of the visibility reduction (diesel engines approximately 15-20%, catalyst-equipped gasoline engines approximately 10-20%, noncatalyst-equipped gasoline engines approximately 3-5%, crustal and paved road dust approximately 5%) in the region with the most severe visibility impairment. Ammonia emissions from animal sources account for approximately 10-15% of the visibility reduction. PMID:14998023

  11. Chemometric techniques in distribution, characterisation and source apportionment of polycyclic aromatic hydrocarbons (PAHS) in aquaculture sediments in Malaysia.

    PubMed

    Retnam, Ananthy; Zakaria, Mohamad Pauzi; Juahir, Hafizan; Aris, Ahmad Zaharin; Zali, Munirah Abdul; Kasim, Mohd Fadhil

    2013-04-15

    This study investigated polycyclic aromatic hydrocarbons (PAHs) pollution in surface sediments within aquaculture areas in Peninsular Malaysia using chemometric techniques, forensics and univariate methods. The samples were analysed using soxhlet extraction, silica gel column clean-up and gas chromatography mass spectrometry. The total PAH concentrations ranged from 20 to 1841 ng/g with a mean of 363 ng/g dw. The application of chemometric techniques enabled clustering and discrimination of the aquaculture sediments into four groups according to the contamination levels. A combination of chemometric and molecular indices was used to identify the sources of PAHs, which could be attributed to vehicle emissions, oil combustion and biomass combustion. Source apportionment using absolute principle component scores-multiple linear regression showed that the main sources of PAHs are vehicle emissions 54%, oil 37% and biomass combustion 9%. Land-based pollution from vehicle emissions is the predominant contributor of PAHs in the aquaculture sediments of Peninsular Malaysia. PMID:23452623

  12. Particulate matter source apportionment in a village situated in industrial region of Central Europe.

    PubMed

    Pokorná, P; Hovorka, J; Krouzek, J; Hopke, P K

    2013-12-01

    The bilinear receptor model positive matrix factorization (PMF) was used to apportion particulate matter with an aerodynamic diameter of 1-10 microm (PM1-10) sources in a village, Brezno, situated in an industrial region of northern Bohemia in Central Europe. The receptor model analyzed the data sets of 90- and 60-min integrations of PM1-10 mass concentrations and elemental composition for 27 elements. The 14-day sampling campaigns were conducted in the village in summer 2008 and winter 2010. Also, to ensure seasonal and regional representativeness of the data sets recorded in the village, the spatial-temporal variability of the 24-hr PM10 and PM1-10 within 2008-2010 in winter and summer across the multiple sites was evaluated. There were statistically significant interseasonal differences of the 24-hr PM data, but not intrasummer or intrawinter differences of the 24-hr PM1-10 data across the multiple sites. PMF resolved seven sources of PM1-10. They were high-temperature coal combustion; combustion in local heating boilers; marine aerosol; mineral dust; primary biological/wood burning; road dust, car brakes; and gypsum. The main summer factors were assigned to mineral dust (38.2%) and primary biological/wood burning (33.1%). In winter, combustion factors dominated (80%) contribution to PM1-10. The conditional probability function (CPF) helped to identified local sources of PM1-10. The source of marine aerosol from the North Sea and English Channel was indicated by the Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT). PMID:24558704

  13. The application of carbon-14 analyses to the source apportionment of atmospheric carbonaceous particulate matter: a review.

    PubMed

    Heal, Mathew R

    2014-01-01

    Organic carbon (OC) and elemental carbon (EC) together constitute a substantial proportion of airborne particulate matter (PM). Insight into the sources of this major contributor to PM is important for policies to mitigate the impact of PM on human health and climate change. In recent years measurement of the abundance of the radioisotope of carbon ((14)C) in samples of PM by accelerator mass spectrometry has been used to help quantify the relative contributions from sources of fossil carbon and contemporary carbon. This review provides an introduction to the different sources of carbon within PM and the role of (14)C measurements, a description of the preparation of PM samples and of the instrumentation used to quantify (14)C, and a summary of the results and source apportionment methods reported in published studies since 2004. All studies report a sizable fraction of the carbonaceous PM as of non-fossil origin. Even for PM collected in urban locations, the proportions of non-fossil carbon generally exceed 30%; typically the proportion in urban background locations is around 40-60% depending on the local influence of biomass burning. Where values have been measured directly, proportions of non-fossil carbon in EC are lower than in OC, reflecting the greater contribution of fossil-fuel combustion to EC and the generally small sources of contemporary EC. Detailed source apportionment studies point to important contributions from biogenic-derived secondary OC, consistent with other evidence of a ubiquitous presence of heavily oxidized background secondary OC. The review concludes with some comments on current issues and future prospects, including progress towards compound-class and individual-compound-specific (14)C analyses. PMID:24136253

  14. A Regional Assessment of Marine Vessel PM2.5 Impacts in the U.S. Pacific Northwest Using a Receptor Based Source Apportionment Method

    EPA Science Inventory

    This work reports the results of a regional receptor-based source apportionment analysis using the Positive Matrix Factorization (PMF) model on chemically speciated PM2.5 data from 36 urban and rural monitoring sites within the U.S. Pacific Northwest. The approach taken is to mo...

  15. Source apportionment of air pollution exposures of rural Chinese women cooking with biomass fuels

    NASA Astrophysics Data System (ADS)

    Huang, Wei; Baumgartner, Jill; Zhang, Yuanxun; Wang, Yuqin; Schauer, James J.

    2015-03-01

    Particulate matter (PM) from different sources may differentially affect human health. Few studies have assessed the main sources of personal exposure to PM and their contributions among residents of developing countries, where pollution sources differ from those in higher-income settings. 116 daily (24-h) personal PM2.5 exposure samples were collected among 81 women cooking with biomass fuels in two villages in rural Yunnan, China. The PM samples were analyzed for mass and chemical composition, including water-soluble organic carbon (WSOC), black carbon (BC), and molecular markers. We found black carbon, n-alkanes and levoglucosan dominated the most abundant fractions of the total measured species and average personal PM2.5 exposure was higher in winter than that in summer in both villages. The composition data were then analyzed using a positive matrix factorization (PMF) receptor model to identify the main PM emission sources contributing to women's exposures and to assess their spatial (between villages) and seasonal variation in our study setting. The 6-factor solution provided reasonably stable profiles and was selected for further analysis. Our results show that rural Chinese women cooking with biomass fuels are exposed to a variety of sources. The identified factors include wood combustion (41.1%), a cooking source (35.6%), a mobile source (12.6%), plant waxes (6.7%), pyrolysis combustion (3.0%), and secondary organic aerosols (SOA; 1.0%). The mean source contributions of the mobile source, cooking source, and wood combustion factor to PM2.5 exposure were significantly different between women living in the two study villages, whereas the mean SOA, wood combustion, and plant waxes factors differed seasonally. There was no relationship between source contributions and questionnaire-based measurements of source-specific exposures, implying that the impacts of source contributions on exposure are affected by complex spatial, temporal and behavioral patterns

  16. Intra-urban biomonitoring: Source apportionment using tree barks to identify air pollution sources.

    PubMed

    Moreira, Tiana Carla Lopes; de Oliveira, Regiani Carvalho; Amato, Luís Fernando Lourenço; Kang, Choong-Min; Saldiva, Paulo Hilário Nascimento; Saiki, Mitiko

    2016-05-01

    It is of great interest to evaluate if there is a relationship between possible sources and trace elements using biomonitoring techniques. In this study, tree bark samples of 171 trees were collected using a biomonitoring technique in the inner city of São Paulo. The trace elements (Al, Ba, Ca, Cl, Cu, Fe, K, Mg, Mn, Na, P, Rb, S, Sr and Zn) were determined by the energy dispersive X-ray fluorescence (EDXRF) spectrometry. The Principal Component Analysis (PCA) was applied to identify the plausible sources associated with tree bark measurements. The greatest source was vehicle-induced non-tailpipe emissions derived mainly from brakes and tires wear-out and road dust resuspension (characterized with Al, Ba, Cu, Fe, Mn and Zn), which was explained by 27.1% of the variance, followed by cement (14.8%), sea salt (11.6%) and biomass burning (10%), and fossil fuel combustion (9.8%). We also verified that the elements related to vehicular emission showed different concentrations at different sites of the same street, which might be helpful for a new street classification according to the emission source. The spatial distribution maps of element concentrations were obtained to evaluate the different levels of pollution in streets and avenues. Results indicated that biomonitoring techniques using tree bark can be applied to evaluate dispersion of air pollution and provide reliable data for the further epidemiological studies. PMID:26995269

  17. Occurrence and source apportionment of pharmaceuticals and personal care products in the Beiyun River of Beijing, China.

    PubMed

    Dai, Guohua; Wang, Bin; Huang, Jun; Dong, Rui; Deng, Shubo; Yu, Gang

    2015-01-01

    This work investigates, for the first time, the occurrence and sources of 15 pharmaceuticals and personal care products (PPCPs) in surface water of Beijing, one of most densely populated cities in the world, in three sampling events representing different seasonal flow conditions. The detection frequencies of most PPCPs were in the range of 50-100%. The median concentrations of the selected PPCPs ranged from not detected to 4200 ng L(-1) (caffeine). Generally, higher PPCP levels were observed in early spring, indicating both low flow condition and cold-water temperature might enhance their persistence. Source apportionment showed freshly discharged untreated sewage (67%) significantly contributed to the PPCP burden in the Beiyun River, which provides important information for environmental management. PMID:25303665

  18. Source apportionment of secondary airborne particulate matter in a polluted atmosphere.

    PubMed

    Mysliwiec, Mitchell J; Kleeman, Michael J

    2002-12-15

    Secondary airborne particulate matter formed from gas-phase pollutants contributes significantly to the most severe particulate air quality events that occur in the United States each year. In this study, a mechanistic air quality model is demonstrated that can predict source contributions to the size distribution of secondary airborne particulate matter. Calculations performed for a typical air quality episode in Southern California show that NOx released from diesel engines and catalyst-equipped gasoline engines account for the majority of the secondary particulate nitrate aerosol measured at inland locations. NH3 released from catalyst-equipped gasoline engines, farm animals, and residential sources account for the majority of the secondary particulate ammonium ion at inland locations in the region. When both tailpipe and road dust emissions are considered, transportation sources dominate the size distribution of total (primary plus secondary) airborne particulate matter in the South Coast Air Basin during the episode studied. These findings suggest that the public health risk associated with air pollution released from transportation sources is significant relative to other public health threats such as traffic accidents. PMID:12521164

  19. [Regional Source Apportionment of PM2.5 in Beijing in January 2013].

    PubMed

    Li, Xuan; Nie, Teng; Qi, Jun; Zhou, Zhen; Sun, Xue-song

    2015-04-01

    In January 2013, Beijing area experienced several severe haze weather events. The pollution of fine particles has become an important problem in Beijing. Understanding the sources of PM2.5 in Beijing is essential for solutions and related policy-formulations. Three-dimensional air quality modelling system was established to analyze the PM2.5 pollution during 20-24 January in 2013. PSAT technology was used to study the regional sources of Beijing PM2.5 pollution. The results showed that local emission was the major source of PM2.5 in Beijing City, with an average contribution rate of 34% . The average contribution rates of Hebei and Tianjin were 26% and 4%, respectively. The neighboring area and the boundary conditions contributed 12% and 24% to PM2.5 in Beijing. In the heavy pollution period, the influence of regional transportation increased significantly, and became the major source of PM2.5 pollution in Beijing. Nitrate in PM2.5 in Beijing mainly came from the surrounding area of Beijing City, while sulfate and secondary organic aerosols showed characteristics of long-distance transportation. Ammonium salt and other components were mainly from Beijing local contribution. PMID:26164884

  20. Atmospheric particulate mercury in the megacity Beijing: Spatio-temporal variations and source apportionment

    NASA Astrophysics Data System (ADS)

    Schleicher, N. J.; Schäfer, J.; Blanc, G.; Chen, Y.; Chai, F.; Cen, K.; Norra, S.

    2015-05-01

    Particulate mercury (HgP) concentrations in weekly aerosol samples (PM2.5 and TSP) from Beijing, China, were measured for a complete year. In addition, spatial differences were measured for a shorter time period at four different sites and potential source materials were analyzed. Average HgP concentrations in PM2.5 samples were 0.26 ng/m3 for day-time PM2.5, 0.28 ng/m3 for night-time PM2.5, and 0.57 ng/m3 for TSP samples, respectively. Coal combustion was identified as the major source of HgP in Beijing. Other sources included industrial activities as well as red color on historical buildings as a minor contribution. Spatial differences were pronounced with highest concentrations in the inner city (inside the 3rd ring road). The results further showed a strong seasonality with highest concentrations in winter and lowest in summer due to local meteorological conditions (precipitation in summer and stagnant conditions and low mixing layer height in winter) as well as seasonal sources, such as coal combustion for heating purposes. Day-night differences also showed a seasonal pattern with higher night-time concentrations during summer and higher day-time concentrations during winter. Compared to other cities worldwide, the HgP concentrations in Beijing were alarmingly high, suggesting that airborne particulate Hg should be the focus of future monitoring activities and mitigation measures.

  1. Water Quality Assessment of River Soan (Pakistan) and Source Apportionment of Pollution Sources Through Receptor Modeling.

    PubMed

    Nazeer, Summya; Ali, Zeshan; Malik, Riffat Naseem

    2016-07-01

    The present study was designed to determine the spatiotemporal patterns in water quality of River Soan using multivariate statistics. A total of 26 sites were surveyed along River Soan and its associated tributaries during pre- and post-monsoon seasons in 2008. Hierarchical agglomerative cluster analysis (HACA) classified sampling sites into three groups according to their degree of pollution, which ranged from least to high degradation of water quality. Discriminant function analysis (DFA) revealed that alkalinity, orthophosphates, nitrates, ammonia, salinity, and Cd were variables that significantly discriminate among three groups identified by HACA. Temporal trends as identified through DFA revealed that COD, DO, pH, Cu, Cd, and Cr could be attributed for major seasonal variations in water quality. PCA/FA identified six factors as potential sources of pollution of River Soan. Absolute principal component scores using multiple regression method (APCS-MLR) further explained the percent contribution from each source. Heavy metals were largely added through industrial activities (28 %) and sewage waste (28 %), nutrients through agriculture runoff (35 %) and sewage waste (28 %), organic pollution through sewage waste (27 %) and urban runoff (17 %) and macroelements through urban runoff (39 %), and mineralization and sewage waste (30 %). The present study showed that anthropogenic activities are the major source of variations in River Soan. In order to address the water quality issues, implementation of effective waste management measures are needed. PMID:27000830

  2. Chemical characterisation of atmospheric aerosols during a 2007 summer field campaign at Brasschaat, Belgium: sources and source processes of biogenic secondary organic aerosol

    NASA Astrophysics Data System (ADS)

    Gómez-González, Y.; Wang, W.; Vermeylen, R.; Chi, X.; Neirynck, J.; Janssens, I. A.; Maenhaut, W.; Claeys, M.

    2012-01-01

    Measurements of organic marker compounds and inorganic species were performed on PM2.5 aerosols from a Belgian forest site that is severely impacted by urban pollution ("De Inslag", Brasschaat, Belgium) during a 2007 summer period within the framework of the "Formation mechanisms, marker compounds, and source apportionment for biogenic atmospheric aerosols (BIOSOL)" project. The measured organic species included (i) low-molecular weight (MW) dicarboxylic acids (LMW DCAs), (ii) methanesulfonate (MSA), (iii) terpenoic acids originating from the oxidation of α-pinene, β-pinene, d-limonene and Δ3-carene, and (iv) organosulfates related to secondary organic aerosol from the oxidation of isoprene and α-pinene. The organic tracers explained, on average, 5.3 % of the organic carbon (OC), of which 0.7 % was due to MSA, 3.4 % to LMW DCAs, 0.6 % to organosulfates, and 0.6 % to terpenoic acids. The highest atmospheric concentrations of most species were observed during the first five days of the campaign, which were characterised by maximum day-time temperatures >22 °C. Most of the terpenoic acids and the organosulfates peaked during day-time, consistent with their local photochemical origin. High concentrations of 3-methyl-1,2,3-butanetricarboxylic acid (MBTCA) and low concentrations of cis-pinonic acid were noted during the first five days of the campaign, indicative of an aged biogenic aerosol. Several correlations between organic species were very high (r>0.85), high (0.70.7) and showed an Arrhenius-type relationship, consistent with their formation through OH radical chemistry.

  3. Source Apportionment of Particle Bound Polycyclic Aromatic Hydrocarbons at an Industrial Location in Agra, India

    PubMed Central

    Lakhani, Anita

    2012-01-01

    16 US EPA priority polycyclic aromatic hydrocarbons (PAHs) were quantified in total suspended ambient particulate matter (TSPM) collected from an industrial site in Agra (India) using gas chromatography. The major industrial activities in Agra are foundries that previously used coal and coke as fuel in cupola furnaces. These foundries have now switched over to natural gas. In addition, use of compressed natural gas has also been promoted and encouraged in automobiles. This study attempts to apportion sources of PAH in the ambient air and the results reflect the advantages associated with the change of fuel. The predominant PAHs in TSPM include high molecular weight (HMW) congeners BghiP, DbA, IP, and BaP. The sum of 16 priority PAHs had a mean value of 72.7 ± 4.7 ng m−3. Potential sources of PAHs in aerosols were identified using diagnostic ratios and principal component analysis. The results reflect a blend of emissions from diesel and natural gas as the major sources of PAH in the city along with contribution from emission of coal, coke, and gasoline. PMID:22606062

  4. Source apportionment of particle bound polycyclic aromatic hydrocarbons at an industrial location in Agra, India.

    PubMed

    Lakhani, Anita

    2012-01-01

    16 U.S. EPA priority polycyclic aromatic hydrocarbons (PAHs) were quantified in total suspended ambient particulate matter (TSPM) collected from an industrial site in Agra (India) using gas chromatography. The major industrial activities in Agra are foundries that previously used coal and coke as fuel in cupola furnaces. These foundries have now switched over to natural gas. In addition, use of compressed natural gas has also been promoted and encouraged in automobiles. This study attempts to apportion sources of PAH in the ambient air and the results reflect the advantages associated with the change of fuel. The predominant PAHs in TSPM include high molecular weight (HMW) congeners BghiP, DbA, IP, and BaP. The sum of 16 priority PAHs had a mean value of 72.7 ± 4.7 ng m(-3). Potential sources of PAHs in aerosols were identified using diagnostic ratios and principal component analysis. The results reflect a blend of emissions from diesel and natural gas as the major sources of PAH in the city along with contribution from emission of coal, coke, and gasoline. PMID:22606062

  5. Particle size distribution of indoor aerosol sources

    SciTech Connect

    Shah, K.B.

    1990-10-24

    As concern about Indoor Air Quality (IAQ) has grown in recent years, it has become necessary to determine the nature of particles produced by different indoor aerosol sources and the typical concentration that these sources tend to produce. These data are important in predicting the dose of particles to people exposed to these sources and it will also enable us to take effective mitigation procedures. Further, it will also help in designing appropriate air cleaners. A new state of the art technique, DMPS (Differential Mobility Particle Sizer) System is used to determine the particle size distributions of a number of sources. This system employs the electrical mobility characteristics of these particles and is very effective in the 0.01--1.0 {mu}m size range. A modified system that can measure particle sizes in the lower size range down to 3 nm was also used. Experimental results for various aerosol sources is presented in the ensuing chapters. 37 refs., 20 figs., 2 tabs.

  6. New insight into the spatiotemporal variability and source apportionments of C1-C4 alkyl nitrates in Hong Kong

    NASA Astrophysics Data System (ADS)

    Ling, Z. H.; Guo, H.; Simpson, I. J.; Saunders, S. M.; Lam, S. H. M.; Lyu, X. P.; Blake, D. R.

    2015-08-01

    Alkyl nitrates (RONO2) were measured concurrently at a mountain site (TMS) and an urban site (TW) at the foot of the same mountain in Hong Kong from September to November 2010, when high O3 mixing ratios were frequently observed. The abundance and temporal patterns of five C1-C4 RONO2 and their parent hydrocarbons (RH), the RONO2/RH ratios and photochemical age of air masses at TMS differed from those at TW, reflecting different contributions of direct emissions and secondary formation of RONO2 at the two sites. Relative to 2-BuONO2/n-butane, the measured ratios of C1-C2 RONO2/RH at the two sites exhibited significant positive deviations from pure photochemical (PP) curves and background initial ratio (BIR) curves obtained from laboratory kinetic data, suggesting that background mixing ratios had a significant influence on the RONO2 and RH distributions. In contrast to the C1-C2 RONO2/RH ratios, the evolution for the measured ratios of C3 RONO2/RH to 2-BuONO2/n-butane agreed well with the ratio distributions in the PP and BIR curves at the two sites. Furthermore, the ratios of 1-/2-PrONO2 and yields of 1- and 2-PrONO2 suggested that the C3 RONO2 were mainly from secondary formation at TMS, whereas secondary formation and other additional sources had a significant influence on C3 RONO2 mixing ratios at TW. The source apportionment results confirmed that secondary formation was the dominant contributor to all the RONO2 at TMS, while most of the RONO2 at TW were from secondary formation and biomass burning. The findings of the source apportionments and photochemical evolution of RONO2 are helpful to evaluate photochemical processing in Hong Kong using RONO2 as an indicator.

  7. Source apportionment of airborne particulate matter in Southeast Texas using a source-oriented 3D air quality model

    NASA Astrophysics Data System (ADS)

    Zhang, Hongliang; Ying, Qi

    2010-09-01

    A nested version of the source-oriented externally mixed UCD/CIT model was developed to study the source contributions to airborne particulate matter (PM) during a two-week long air quality episode during the Texas 2000 Air Quality Study (TexAQS 2000). Contributions to primary PM and secondary ammonium sulfate in the Houston-Galveston Bay (HGB) and Beaumont-Port Arthur (BPA) areas were determined. The predicted 24-h elemental carbon (EC), organic compounds (OC), sulfate, ammonium ion and primary PM 2.5 mass are in good agreement with filter-based observations. Predicted concentrations of hourly sulfate, ammonium ion, and primary OC from diesel and gasoline engines and biomass burning organic aerosol (BBOA) at La Porte, Texas agree well with measurements from an Aerodyne Aerosol Mass Spectrometer (AMS). The UCD/CIT model predicts that EC is mainly from diesel engines and majority of the primary OC is from internal combustion engines and industrial sources. Open burning contributes large fractions of EC, OC and primary PM 2.5 mass. Road dust, internal combustion engines and industries are the major sources of primary PM 2.5. Wildfire dominates the contributions to all primary PM components in areas near the fires. The predicted source contributions to primary PM are in general agreement with results from a chemical mass balance (CMB) model. Discrepancy between the two models suggests that further investigations on the industrial PM emissions are necessary. Secondary ammonium sulfate accounts for the majority of the secondary inorganic PM. Over 80% of the secondary sulfate in the 4 km domain is produced in upwind areas. Coal combustion is the largest source of sulfate. Ammonium ion is mainly from agriculture sources and contributions from gasoline vehicles are significant in urban areas.

  8. Real-time measurements of ambient aerosols in a polluted Indian city: Sources, characteristics, and processing of organic aerosols during foggy and nonfoggy periods

    NASA Astrophysics Data System (ADS)

    Chakraborty, Abhishek; Bhattu, Deepika; Gupta, Tarun; Tripathi, Sachchida N.; Canagaratna, Manjula R.

    2015-09-01

    A detailed time-resolved chemical characterization of ambient nonrefractory submicron aerosols (NR-PM1) was conducted for the first time in India. The measurements were performed during the winter (November 2011 to January 2012) in a heavily polluted city of Kanpur, which is situated in the Indo-Gangetic Plain. Real-time measurements provided new insights into the sources and evolution of organic aerosols (OA) that could not be obtained using previously deployed filter-based measurements at this site. The average NR-PM1 loading was very high (>100 µg/m3) throughout the study, with OA contributing approximately 70% of the total aerosol mass. Source apportionment of the OA using positive matrix factorization revealed large contributions from fresh and aged biomass burning OA throughout the entire study period. A back trajectory analysis showed that the polluted air masses were affected by local sources and distant source regions where the burning of paddy residues occurs annually during winter. Several fog episodes were encountered during the study, and the OA composition varied between foggy and nonfoggy periods, with higher oxygen to carbon (O/C) ratios during the foggy periods. The evolution of OA and their elemental ratios (O:C and H:C) were investigated for the possible effects of fog processing.

  9. Sources apportionment of PM2.5 in a background site in the North China Plain.

    PubMed

    Yao, Lan; Yang, Lingxiao; Yuan, Qi; Yan, Chao; Dong, Can; Meng, Chuanping; Sui, Xiao; Yang, Fei; Lu, Yaling; Wang, Wenxing

    2016-01-15

    To better understand the sources and potential source regions of PM2.5, a field study was conducted from January 2011 to November 2011 at a background site, the Yellow River Delta National Nature Reserve (YRDNNR) in the North China Plain. Positive matrix factorisation (PMF) analysis and a potential source contribution function (PSCF) model were used to assess the data, which showed that YRDNNR experienced serious air pollution. Concentrations of PM2.5 at YRDNNR were 71.2, 92.7, 97.1 and 62.5 μg m(-3) in spring, summer, autumn and winter, respectively, with 66.0% of the daily samples exhibiting higher concentrations of PM2.5 than the national air quality standard. PM2.5 mass closure showed remarkable seasonal variations. Sulphate, nitrate and ammonium were the dominant fractions of PM2.5 in summer (58.0%), whereas PM2.5 was characterized by a high load of organic aerosols (40.2%) in winter. PMF analysis indicated that secondary sulphate and nitrate (54.3%), biomass burning (15.8%), industry (10.7%), crustal matter (8.3%), vehicles (5.2%) and copper smelting (4.9%) were important sources of PM2.5 at YRDNNR on an annual average. The source of secondary sulphate and nitrate was probably industrial coal combustion. PSCF analysis indicated a significant regional impact on PM2.5 at YRDNNR all year round. Local emission may be non-negligible at YRDNNR in summer. The results of the present study provide a scientific basis for the development of PM2.5 control strategies on a regional scale. PMID:26433327

  10. Functional group composition of ambient and source organic aerosols determined by tandem mass spectrometry

    NASA Astrophysics Data System (ADS)

    Dron, J.; El Haddad, I.; Temime-Roussel, B.; Jaffrezo, J.-L.; Wortham, H.; Marchand, N.

    2010-08-01

    The functional group composition of various organic aerosols (OA) is investigated using a recently developed analytical approach based on atmospheric pressure chemical ionisation-tandem mass spectrometry (APCI-MS/MS). The determinations of three functional groups contents are performed quantitatively by neutral loss (carboxylic and carbonyl groups, R-COOH and R-CO-Ŕ respectively) and precursor ion (nitro groups, R-NO2) scanning modes of a tandem mass spectrometer. Major organic aerosol sources are studied: vehicular emission and wood combustion for primary aerosol sources; and a secondary organic aerosol (SOA) produced through photooxidation of o-xylene. The results reveal significant differences in the functional group contents of these source aerosols. The laboratory generated SOA is dominated by carbonyls while carboxylics are preponderate in the wood combustion particles. On the other hand, vehicular emissions are characterised by a strong nitro content. The total amount of the three functional groups accounts for 1.7% (vehicular) to 13.5% (o-xylene photooxidation) of the organic carbon. Diagnostic functional group ratios are then used to tentatively discriminate sources of particles collected in an urban background environment located in an Alpine valley (Chamonix, France) during a strong winter pollution event. The three functional groups under study account for a total functionalisation rate of 2.2 to 3.8% of the organic carbon in this ambient aerosol, which is also dominated by carboxylic moieties. In this particular case study of a deep alpine valley during winter, we show that the nitro- and carbonyl-to-carboxylic diagnostic ratios can be a useful tool to discriminate sources. In these conditions, the total OA concentrations are highly dominated by wood combustion OA. This result is confirmed by an organic markers source apportionment approach which assess a wood burning organic carbon contribution of about 60%. Finally, examples of functional group mass

  11. PM2.5 pollution in a megacity of southwest China: source apportionment and implication

    NASA Astrophysics Data System (ADS)

    Tao, J.; Gao, J.; Zhang, L.; Zhang, R.; Che, H.; Zhang, Z.; Lin, Z.; Jing, J.; Cao, J.; Hsu, S.-C.

    2014-02-01

    Daily PM2.5 (aerosol particles with an aerodynamic diameter of less than 2.5 μm) samples were collected at an urban site in Chengdu, an inland megacity in southwest China, during four one-month periods in 2011, with each period in a different season. Samples were subjected to chemical analysis for various chemical components ranging from major water-soluble ions, organic carbon (OC), element carbon (EC), trace elements to biomass burning tracers, anhydrosugar levoglucosan (LG) and mannosan (MN). Two models, ISORROPIA-II thermodynamic equilibrium model and positive matrix factorization (PMF) model, were applied to explore the likely chemical forms of ionic constituents and to apportion sources for PM2.5. Distinctive seasonal patterns of PM2.5 and associated main chemical components were identified and could be explained by varying emission sources and meteorological conditions. PM2.5 showed a typical seasonality of waxing in winter and waning in summer, with an annual mean of 119 μg m-3. Mineral soil concentrations increased in spring whereas biomass burning species elevated in autumn and winter. Six major source factors were identified to have contributed to PM2.5 using the PMF model. These were secondary inorganic aerosols, coal combustion, biomass burning, iron and steel manufacturing, Mo-related industries, and soil dust, and they contributed 37 ± 18%, 20 ± 12%, 11 ± 10%, 11 ± 9%, 11 ± 9%, and 10 ± 12%, respectively, to PM2.5 masses on annual average, while exhibiting large seasonal variability. On annual average, the unknown emission sources that were not identified by the PMF model contributed 1 ± 11% to the measured PM2.5 mass. Various chemical tracers were used for validating PMF performance. Antimony (Sb) was suggested to be a suitable tracer of coal combustion in Chengdu. Results of LG and MN helped constrain the biomass burning sources, with wood burning dominating in winter and agricultural waste burning dominating in autumn. Excessive Fe (Ex

  12. PM2.5 pollution in a megacity of southwest China: source apportionment and implication

    NASA Astrophysics Data System (ADS)

    Tao, J.; Gao, J.; Zhang, L.; Zhang, R.; Che, H.; Zhang, Z.; Lin, Z.; Jing, J.; Cao, J.; Hsu, S.-C.

    2014-08-01

    Daily PM2.5 (aerosol particles with an aerodynamic diameter of less than 2.5 μm) samples were collected at an urban site in Chengdu, an inland megacity in southwest China, during four 1-month periods in 2011, with each period in a different season. Samples were subject to chemical analysis for various chemical components ranging from major water-soluble ions, organic carbon (OC), element carbon (EC), trace elements to biomass burning tracers, anhydrosugar levoglucosan (LG), and mannosan (MN). Two models, the ISORROPIA II thermodynamic equilibrium model and the positive matrix factorization (PMF) model, were applied to explore the likely chemical forms of ionic constituents and to apportion sources for PM2.5. Distinctive seasonal patterns of PM2.5 and associated main chemical components were identified and could be explained by varying emission sources and meteorological conditions. PM2.5 showed a typical seasonality of waxing in winter and waning in summer, with an annual mean of 119 μg m-3. Mineral soil concentrations increased in spring, whereas biomass burning species elevated in autumn and winter. Six major source factors were identified to have contributed to PM2.5 using the PMF model. These were secondary inorganic aerosols, coal combustion, biomass burning, iron and steel manufacturing, Mo-related industries, and soil dust, and they contributed 37 ± 18, 20 ± 12, 11 ± 10, 11 ± 9, 11 ± 9, and 10 ± 12%, respectively, to PM2.5 masses on annual average, while exhibiting large seasonal variability. On annual average, the unknown emission sources that were not identified by the PMF model contributed 1 ± 11% to the measured PM2.5 mass. Various chemical tracers were used for validating PMF performance. Antimony (Sb) was suggested to be a suitable tracer of coal combustion in Chengdu. Results of LG and MN helped constrain the biomass burning sources, with wood burning dominating in winter and agricultural waste burning dominating in autumn. Excessive Fe (Ex

  13. Source apportionment of ambient PM2.5 in Santiago, Chile: 1999 and 2004 results.

    PubMed

    Jorquera, Héctor; Barraza, Francisco

    2012-10-01

    A receptor model analysis has been applied to ambient PM(2.5) measurements taken at Santiago, Chile (33.5°S, 70.7°W) in 2004 (117 samples) and in 1999 (95 samples) on a receptor site on the eastern side of the city. For both campaigns, six sources have been identified at Santiago and their contributions in 1999/2004 are: motor vehicles: 28 ± 2.5/31.2 ± 3.4%, wood burning: 24.8 ± 2.3/28.9 ± 3.3%, sulfates: 18.8 ± 1.7/16.2 ± 2.5%, marine aerosol: 13 ± 2.1/9.9 ± 1.5%, copper smelters: 11.5 ± 1.4/9.7 ± 3.3% and soil dust: 3.9 ± 1.5/4.0 ± 2.4%. Hence relative contributions are statistically the same but the absolute contributions have been reduced because ambient PM(2.5) has decreased from 34.2 to 25.1 μg/m(3) between 1999 and 2004 at Santiago. Similarity of results for both data sets - analyzed with different techniques at different laboratory facilities - shows that the analysis performed here is robust. Source identification was carried out by inspection of key species in source profiles, seasonality of source contributions, comparison with published source profiles and by looking at wind trajectories computed using the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) from USA's National Oceanic and Atmospheric Administration (NOAA); for the wood burning sources the MODIS burned area daily product was used to confirm wildfire events along the year. Using this combined methodology we have shown conclusively that: a) marine air masses do reach Santiago's basin in significant amounts but combined with anthropogenic sources; b) all copper smelters surrounding Santiago - and perhaps coal-fired power plants as well - contribute to ambient PM(2.5); c) wood burning is the second largest source, coming from residential wood burning in fall and winter and from regional wildfires in spring and summer. The results of the present analysis can be used to improve emission inventories, air quality forecasting systems and cost-benefit analyses at local

  14. Source Apportionment of Elemental Carbon Across the San Francisco Bay Area Using Combined Radiocarbon and Chemical Mass Balances

    NASA Astrophysics Data System (ADS)

    Yoon, S.; Fairley, D.; Sheesley, R. J.

    2014-12-01

    The San Francisco Bay Area is impacted by ambient particulate matter (PM) from a variety of sources including motor vehicles, biomass burning, off-road vehicles, industry, and meat cooking. Ambient PM, especially fine PM (diameter less than 2.5μm, PM2.5), is known to negatively impact health. Elemental Carbon (EC) is one of the major constituents of PM2.5. It not only negatively affects health but is also a powerful short-lived climate forcer. The State of California and Bay Area Air Quality Management District (BAAQMD) have made efforts in regulating contribution of EC from diesel trucks and wood burning, respectively. These and other efforts have assisted in significantly reducing the annual average PM2.5 concentrations approximately 30% since 2005 and 70% since 1990. Despite these improvements, to better determine the relative contribution of contemporary vs. fossil carbon, radiocarbon source apportionment of EC was conducted on PM2.5 collected in the Bay Area. Measurements of the abundance of 14C in the EC fractions are used to quantify the relative contributions of fossil carbon (fossil fuel combustion, including motor vehicle exhaust) and contemporary carbon (biomass combustion and meat cooking). This comprehensive study included seven sites in the Bay Area and 12 months of sampling starting November 2011 through October 2012. The samples were composited to represent winter (November-February) and non-winter (March-October). In addition to radiocarbon analysis, Chemical Mass Balance (CMB) analysis using bulk PM2.5 composition and selected trace gases was used to understand the split among gasoline, natural gas, and diesel exhaust. Preliminary apportionment of the seven sites shows roughly equal contributions of fossil fuel and biomass burning/cooking for both winter and non-winter samples. There is evidence that the diesel contribution to EC, in particular, has decreased substantially over the last decade.

  15. Evaluation and Source Apportionment of Heavy Metals (HMs) in Sewage Sludge of Municipal Wastewater Treatment Plants (WWTPs) in Shanxi, China

    PubMed Central

    Duan, Baoling; Liu, Fenwu; Zhang, Wuping; Zheng, Haixia; Zhang, Qiang; Li, Xiaomei; Bu, Yushan

    2015-01-01

    Heavy metals (HMs) in sewage sludge have become the crucial limiting factors for land use application. Samples were collected and analyzed from 32 waste water treatment plants (WWTPs) in the Shanxi Province, China. HM levels in sewage sludge were assessed. The multivariate statistical method principal component analysis (PCA) was applied to identify the sources of HMs in sewage sludge. HM pollution classes by geochemical accumulation index Igeo and correlation analyses between HMs were also conducted. HMs were arranged in the following decreasing order of mean concentration: Zn > Cu > Cr > Pb > As > Hg > Cd; the maximum concentrations of all HMs were within the limit of maximum content permitted by Chinese discharge standard. Igeo classes of HMs pollution in order from most polluted to least were: Cu and Hg pollution were the highest; Cd and Cr pollution were moderate; Zn, As and Pb pollution were the least. Sources of HM contamination in sewage sludge were identified as three components. The primary contaminant source accounting for 35.7% of the total variance was identified as smelting industry, coking plant and traffic sources; the second source accounting for 29.0% of the total variance was distinguished as household and water supply pollution; the smallest of the three sources accounting for 16.2% of the total variance was defined as special industries such as leather tanning, textile manufacturing and chemical processing industries. Source apportionment of HMs in sewage sludge can control HM contamination through suggesting improvements in government policies and industrial processes. PMID:26690464

  16. Evaluation and Source Apportionment of Heavy Metals (HMs) in Sewage Sludge of Municipal Wastewater Treatment Plants (WWTPs) in Shanxi, China.

    PubMed

    Duan, Baoling; Liu, Fenwu; Zhang, Wuping; Zheng, Haixia; Zhang, Qiang; Li, Xiaomei; Bu, Yushan

    2015-12-01

    Heavy metals (HMs) in sewage sludge have become the crucial limiting factors for land use application. Samples were collected and analyzed from 32 waste water treatment plants (WWTPs) in the Shanxi Province, China. HM levels in sewage sludge were assessed. The multivariate statistical method principal component analysis (PCA) was applied to identify the sources of HMs in sewage sludge. HM pollution classes by geochemical accumulation index I(geo) and correlation analyses between HMs were also conducted. HMs were arranged in the following decreasing order of mean concentration: Zn > Cu > Cr > Pb > As > Hg > Cd; the maximum concentrations of all HMs were within the limit of maximum content permitted by Chinese discharge standard. I(geo) classes of HMs pollution in order from most polluted to least were: Cu and Hg pollution were the highest; Cd and Cr pollution were moderate; Zn, As and Pb pollution were the least. Sources of HM contamination in sewage sludge were identified as three components. The primary contaminant source accounting for 35.7% of the total variance was identified as smelting industry, coking plant and traffic sources; the second source accounting for 29.0% of the total variance was distinguished as household and water supply pollution; the smallest of the three sources accounting for 16.2% of the total variance was defined as special industries such as leather tanning, textile manufacturing and chemical processing industries. Source apportionment of HMs in sewage sludge can control HM contamination through suggesting improvements in government policies and industrial processes. PMID:26690464

  17. A stable isotope approach for source apportionment of chlorinated ethene plumes at a complex multi-contamination events urban site.

    PubMed

    Nijenhuis, Ivonne; Schmidt, Marie; Pellegatti, Eleonora; Paramatti, Enrico; Richnow, Hans Hermann; Gargini, Alessandro

    2013-10-01

    The stable carbon isotope composition of chlorinated aliphatic compounds such as chlorinated methanes, ethanes and ethenes was examined as an intrinsic fingerprint for apportionment of sources. A complex field site located in Ferrara (Italy), with more than 50years history of use of chlorinated aliphatic compounds, was investigated in order to assess contamination sources. Several contamination plumes were found in a complex alluvial sandy multi-aquifer system close to the river Po; sources are represented by uncontained former industrial and municipal dump sites as well as by spills at industrial areas. The carbon stable isotope signature allowed distinguishing 2 major sources of contaminants. One source of chlorinated aliphatic contaminants was strongly depleted in ¹³C (<-60‰) suggesting production lines which have used depleted methane for synthesis. The other source had typical carbon isotope compositions of >-40‰ which is commonly observed in recent production of chlorinated solvents. The degradation processes in the plumes could be traced interpreting the isotope enrichment and depletion of parent and daughter compounds, respectively. We demonstrate that, under specific production conditions, namely when highly chlorinated ethenes are produced as by-product during chloromethanes production, ¹³C depleted fingerprinting of contaminants can be obtained and this can be used to track sources and address the responsible party of the pollution in urban areas. PMID:24077332

  18. Sources of atmospheric aerosol from long-term measurements (5 years) of chemical composition in Athens, Greece.

    PubMed

    Paraskevopoulou, D; Liakakou, E; Gerasopoulos, E; Mihalopoulos, N

    2015-09-15

    To identify the sources of aerosols in Greater Athens Area (GAA), a total of 1510 daily samples of fine (PM 2.5) and coarse (PM 10-2,5) aerosols were collected at a suburban site (Penteli), during a five year period (May 2008-April 2013) corresponding to the period before and during the financial crisis. In addition, aerosol sampling was also conducted in parallel at an urban site (Thissio), during specific, short-term campaigns during all seasons. In all these samples mass and chemical composition measurements were performed, the latest only at the fine fraction. Particulate organic matter (POM) and ionic masses (IM) are the main contributors of aerosol mass, equally contributing by accounting for about 24% of the fine aerosol mass. In the IM, nss-SO4(-2) is the prevailing specie followed by NO3(-) and NH4(+) and shows a decreasing trend during the 2008-2013 period similar to that observed for PM masses. The contribution of water in fine aerosol is equally significant (21 ± 2%), while during dust transport, the contribution of dust increases from 7 ± 2% to 31 ± 9%. Source apportionment (PCA and PMF) and mass closure exercises identified the presence of six sources of fine aerosols: secondary photochemistry, primary combustion, soil, biomass burning, sea salt and traffic. Finally, from winter 2012 to winter 2013 the contribution of POM to the urban aerosol mass is increased by almost 30%, reflecting the impact of wood combustion (dominant fuel for domestic heating) to air quality in Athens, which massively started in winter 2013. PMID:25958364

  19. Spatial and seasonal variation and source apportionment of volatile organic compounds (VOCs) in a heavily industrialized region

    NASA Astrophysics Data System (ADS)

    Dumanoglu, Yetkin; Kara, Melik; Altiok, Hasan; Odabasi, Mustafa; Elbir, Tolga; Bayram, Abdurrahman

    2014-12-01

    Source apportionment is generally applied to a time series of pollutant concentrations measured at a single site. However, in a complex airshed having multiple pollutant sources, it may be helpful to collect samples from several sites to ensure that some of them have low contributions from specific sources. Ambient air samples (n = 160) were collected by passive sampling during four seasons in 2009 and 2010 at forty different sites in Aliaga, Turkey to determine the spatial, seasonal variations and possible sources of volatile organic compounds (VOCs). Fifty-eight VOCs (Σ58VOC) were detected. Σ58VOC concentrations ranged between 0.1 and 1770 μg m-3 (avg ± SD, 67 ± 193 μg m-3). Aliphatic hydrocarbons were generally predominant with a high percentage of contribution (31%-88%) at all sites. Aromatic VOCs were the second highest group (8-50%), followed by halogenated VOCs (1-24%) and oxygenated VOCs (0.04-5.9%). Highly variable spatial distribution of ambient VOC concentrations suggested that the major sources in this region were industrial plants. Generally, VOC concentrations were higher in summer than in winter probably due to increased volatilization from their sources at higher ambient temperatures. However, high atmospheric VOC concentrations were also observed in winter and fall near the petroleum refinery and petrochemical complex, probably due to the calm conditions and high atmospheric stability that is commonly encountered during the winter months in the area, restricting the dilution of pollutants. The newest version of EPA PMF (V5.0) (Positive Matrix Factorization) having the capability of handling multiple site data was used for source apportionment. Refinery and petroleum products, petrochemical industry, solvent use and industrial processes, and vehicle exhaust were the identified VOC sources in the study area, contributing 56%, 22%, 12%, and 10%, respectively to the Σ58VOC concentrations. Carcinogenic risks due to lifetime exposure to seven VOCs

  20. Impacts of Oil and Gas Production on Winter Ozone Pollution in the Uintah Basin Using Model Source Apportionment

    NASA Astrophysics Data System (ADS)

    Tran, H. N. Q.; Tran, T. T.; Mansfield, M. L.; Lyman, S. N.

    2014-12-01

    Contributions of emissions from oil and gas activities to elevated ozone concentrations in the Uintah Basin - Utah were evaluated using the CMAQ Integrated Source Apportionment Method (CMAQ-ISAM) technique, and were compared with the results of traditional budgeting methods. Unlike the traditional budgeting method, which compares simulations with and without emissions of the source(s) in question to quantify its impacts, the CMAQ-ISAM technique assigns tags to emissions of each source and tracks their evolution through physical and chemical processes to quantify the final ozone product yield from the source. Model simulations were performed for two episodes in winter 2013 of low and high ozone to provide better understanding of source contributions under different weather conditions. Due to the highly nonlinear ozone chemistry, results obtained from the two methods differed significantly. The growing oil and gas industry in the Uintah Basin is the largest contributor to the elevated zone (>75 ppb) observed in the Basin. This study therefore provides an insight into the impact of oil and gas industry on the ozone issue, and helps in determining effective control strategies.

  1. Concentrations and source apportionment of PM10 and associated elemental and ionic species in a lignite-burning power generation area of southern Greece.

    PubMed

    Argyropoulos, G; Grigoratos, Th; Voutsinas, M; Samara, C

    2013-10-01

    Ambient concentrations of PM10 and associated elemental and ionic species were measured over the cold and the warm months of 2010 at an urban and two rural sites located in the lignite-fired power generation area of Megalopolis in Peloponnese, southern Greece. The PM10 concentrations at the urban site (44.2 ± 33.6 μg m(-3)) were significantly higher than those at the rural sites (23.7 ± 20.4 and 22.7 ± 26.9 μg m(-3)). Source apportionment of PM10 and associated components was accomplished by an advanced computational procedure, the robotic chemical mass balance model (RCMB), using chemical profiles for a variety of local fugitive dust sources (power plant fly ash, flue gas desulfurization wet ash, feeding lignite, infertile material from the opencast mines, paved and unpaved road dusts, soil), which were resuspended and sampled through a PM10 inlet onto filters and then chemically analyzed, as well as of other common sources such as vehicular traffic, residential oil combustion, biomass burning, uncontrolled waste burning, marine aerosol, and secondary aerosol formation. Geological dusts (road/soil dust) were found to be major PM10 contributors in both the cold and warm periods of the year, with average annual contribution of 32.6 % at the urban site vs. 22.0 and 29.0 % at the rural sites. Secondary aerosol also appeared to be a significant source, contributing 22.1 % at the urban site in comparison to 30.6 and 28.7 % at the rural sites. At all sites, the contribution of biomass burning was most significant in winter (28.2 % at the urban site vs. 14.6 and 24.6 % at the rural sites), whereas vehicular exhaust contribution appeared to be important mostly in the summer (21.9 % at the urban site vs. 11.5 and 10.5 % at the rural sites). The highest contribution of fly ash (33.2 %) was found at the rural site located to the north of the power plants during wintertime, when winds are favorable. In the warm period, the highest contribution of fly ash was found at the

  2. A framework of characteristics identification and source apportionment of water pollution in a river: a case study in the Jinjiang River, China.

    PubMed

    Chen, Haiyang; Teng, Yanguo; Wang, Jinsheng

    2012-01-01

    A framework for characteristics identification and source apportionment of water pollution in the Jinjiang River of China was proposed in this study for evaluation. A total of 114 water samples which were generated between May 2009 and September 2010 at 13 sites were collected and analysed. First, support vector machine (SVM) and water quality pollutant index (WQPI) were used for water quality comprehensive evaluation and identifying characteristic contaminants. Later, factor analysis with nonnegative constraints (FA-NNC) was employed for source apportionment. Finally, multi-linear regression of the absolute principal component score (APCS/MLR) was applied to further estimate source contributions for each characteristic contaminant. The results indicated that the water quality of the Jinjiang River was mainly at the third level (65.79%) based on national surface water quality permissible standards in China. Ammonia nitrogen, total phosphorus, mercury, iron and manganese were identified as characteristic contaminants. Source apportionment results showed that industrial activities (63.16%), agricultural non-point source (16.50%) and domestic sewage (12.85%) were the main anthropogenic pollution sources which were influencing the water quality of Jinjiang River. This proposed method provided a helpful framework for conducting water pollution management in aquatic environment. PMID:22592480

  3. Source Apportionment of PM2.5 in Beijing, China Using Organic Tracers

    NASA Astrophysics Data System (ADS)

    Zheng, M.; Cass, G. R.; Salmon, L. G.; Schauer, J. J.

    2001-12-01

    In 2000, the annual average concentration of PM2.5 measured at five air quality monitoring sites in Beijing, China was found to be 101 micrograms per cubic meter, which is significantly higher than the annual average fine particle concentrations in many North American and European urban locations. Such high concentrations of airborne fine particulate matter lead to a variety of air quality problems including severe visibility reduction. Development of an effective strategy for reducing the air pollution emissions in Beijing requires a clear understanding of the composition, concentration, and sources of these fine particles in the atmosphere. Daily average PM2.5 samples were collected simultaneously once every 6th day at five air quality monitoring stations in Beijing, China during January, April, July, and October 2000. The samples obtained each month at each site were combined as a monthly composite sample for detailed organic tracer analysis by GC/MS (gas chromatography/mass spectrometry). The concentrations of one hundred organic compounds were quantified in each composite sample, including n-alkanes, branched alkanes, cycloalkanes, n-alkanoic acids, n-alkenoic acids, PAHs (polycyclic aromatic hydrocarbons), oxy-PAHs, hopanes, steranes, alkanedioic acids, resin acids, aromatic acids as well as key molecular marker compounds. The identified organic tracers along with elemental carbon, organic carbon, Al and Si which have been previously quantified were applied in a chemical mass balance model to apportion the sources contributing to PM2.5 mass. The major sources include coal combustion, wood burning, gasoline-power vehicle exhaust, diesel exhaust, crustal material, meat cooking, vegetative detritus, as well as secondary aerosol formation. Significant seasonal variations in the source contributions to PM2.5 were observed, e.g., higher contribution from crustal material in April and higher concentration from coal combustion in January. The highest concentration of

  4. Source apportionment of PM2.5 at multiple sites in Venice (Italy): Spatial variability and the role of weather

    NASA Astrophysics Data System (ADS)

    Masiol, Mauro; Squizzato, Stefania; Rampazzo, Giancarlo; Pavoni, Bruno

    2014-12-01

    This study investigates the chemical speciation of fine particulate matter (PM2.5) collected at three sites in the Venice area, eastern Po Valley (Italy). This area is one of the few hot spots left in Europe where levels of PM2.5 frequently breach EU target values and cause a serious risk for public health. Elemental composition, inorganic ions and polycyclic aromatic hydrocarbon concentrations were quantified in 448 PM2.5 samples and the multiple-site PMF receptor model was based on the elemental and inorganic ion data. Six factors associated with potential sources were quantified, namely, secondary sulfate, ammonium nitrate and combustions, fossil fuels, traffic, industrial and glassmaking. Source apportionment results were further processed using a series of chemometric tools for returning additional information about the seasonal and spatial changes of factors extracted by the PMF analysis. In addition, PMF results were also studied in combination with weather conditions and PAH concentrations revealing that sources of secondary nitrate and sulfate are homogeneously distributed throughout the area, while remaining pollutant sources may have a distinct origin. PMF results were cluster analyzed to sort out samples with similar source profiles and then the wind roses of grouped samples were examined to assess the role of wind speed and direction on PM2.5 pollution and chemistry. The tested tools and the results obtained can be used for air quality assessment studies and air pollution reduction strategies.

  5. Source apportionment of ambient fine particle from combined size distribution and chemical composition data during summertime in Beijing

    NASA Astrophysics Data System (ADS)

    Liu, Z. R.; Wang, Y. S.; Liu, Q.; Hu, B.; Sun, Y.

    2013-01-01

    Continuous particle number concentration and chemical composition data were collected over one month during summertime in Beijing to investigate the source apportionment of ambient fine particles. Particle size distributions from 15 nm to 2.5 μm in diameter and composition data, such as organic matter, sulfate, nitrate, ammonium, chlorine, and gaseous pollutants, were analyzed using positive matrix factorisation (PMF) which indentified eight factors: cooking, solid mode exhaust, nucleation mode exhaust, accumulation mode, secondary nitrate, secondary sulfate, coal-fired power plant and road dust. Nearly two-thirds of particle number concentrations were attributed to cooking (22.8%) and motor vehicle (37.5%), whereas road dust, coal-fired power plant and regional sources contributed 69.0% to particle volume concentrations. Local and remote sources were distinguished using size distributions associated with each factor. Local sources were generally characterised by unimodal or bimodal number distributions, consisting mostly of particles less 0.1 μm in diameter, and regional sources were defined by mostly accumulation mode particles. Nearly one third of secondary nitrate and secondary sulfate was transported from the surrounding areas of Beijing during study period. Overall the introduction of combination of particle number concentration and chemical composition in PMF model is successful at separating the components and quantifying relative contributions to the particle number and volume population in a complex urban atmosphere.

  6. Positive matrix factorization as source apportionment of soil lead and cadmium around a battery plant (Changxing County, China).

    PubMed

    Xue, Jian-long; Zhi, Yu-you; Yang, Li-ping; Shi, Jia-chun; Zeng, Ling-zao; Wu, Lao-sheng

    2014-06-01

    Chemical compositions of soil samples are multivariate in nature and provide datasets suitable for the application of multivariate factor analytical techniques. One of the analytical techniques, the positive matrix factorization (PMF), uses a weighted least square by fitting the data matrix to determine the weights of the sources based on the error estimates of each data point. In this research, PMF was employed to apportion the sources of heavy metals in 104 soil samples taken within a 1-km radius of a lead battery plant contaminated site in Changxing County, Zhejiang Province, China. The site is heavily contaminated with high concentrations of lead (Pb) and cadmium (Cd). PMF successfully partitioned the variances into sources related to soil background, agronomic practices, and the lead battery plants combined with a geostatistical approach. It was estimated that the lead battery plants and the agronomic practices contributed 55.37 and 29.28%, respectively, for soil Pb of the total source. Soil Cd mainly came from the lead battery plants (65.92%), followed by the agronomic practices (21.65%), and soil parent materials (12.43%). This research indicates that PMF combined with geostatistics is a useful tool for source identification and apportionment. PMID:24622990

  7. Sources and composition of urban aerosol particles

    NASA Astrophysics Data System (ADS)

    Vogt, M.; Johansson, C.; Mårtensson, M.; Struthers, H.; Ahlm, L.; Nilsson, D.

    2011-09-01

    From May 2008 to March 2009 aerosol emissions were measured using the eddy covariance method covering the size range 0.25 to 2.5 μm diameter (Dp) from a 105 m tower, in central Stockholm, Sweden. Supporting chemical aerosol data were collected at roof and street level. Results show that the inorganic fraction of sulfate, nitrate, ammonium and sea salt accounts for approximately 15% of the total aerosol mass <1 μm Dp (PM1) with water soluble soil contributing 11% and water insoluble soil 47%. Carbonaceous compounds were at the most 27% of PM1 mass. It was found that heating the air from the tower to 200 °C resulted in the loss of approximately 60% of the aerosol volume at 0.25 μm Dp whereas only 40% of the aerosol volume was removed at 0.6 μm Dp. Further heating to 300 °C caused very little additional losses <0.6 μm Dp. The chemical analysis did not include carbonaceous compounds, but based on the difference between the total mass concentration and the sum of the analyzed non-carbonaceous materials, it can be assumed that the non-volatile particulate material (heated to 300 °C) consists mainly of carbonaceous compounds, including elemental carbon. Furthermore, it was found that the non-volatile particle fraction <0.6 μm Dp correlated (r2 = 0.4) with the BC concentration at roof level in the city, supporting the assumption that the non-volatile material consists of carbonaceous compounds. The average diurnal cycles of the BC emissions from road traffic (as inferred from the ratio of the incremental concentrations of nitrogen oxides (NOx) and BC measured on a densely trafficked street) and the fluxes of non-volatile material at tower level are in close agreement, suggesting a traffic source of BC. We have estimated the emission factors (EFs) for non-volatile particles <0.6 μm Dp to be 2.4±1.4 mg veh-1 km-1 based on either CO2 fluxes or traffic activity data. Light (LDV) and heavy duty vehicle (HDV) EFs were estimated using multiple linear regression and

  8. Chemical mass balance source apportionment of TSP in a lignite-burning area of Western Macedonia, Greece

    NASA Astrophysics Data System (ADS)

    Samara, Constantini

    Total suspended particle mass concentrations (TSP) were determined in the Kozani-Ptolemais-Florina basin (western Macedonia, Greece), an area with intensive lignite burning for power generation. The study was conducted over a 1-year period (November 2000-November 2001) at 10 receptor sites located at variable distances from the power plants. Ambient TSP samples were analyzed for 27 major, minor and trace elements. Particulate emissions were also collected from a variety of sources including fly ash, lignite dust, automobile traffic, domestic heating, and open-air burning of agricultural biomass and refuse, and analyzed for the same chemical components. Ambient and source chemical profiles were used for source identification and apportionment of TSP by employing a chemical mass balance (CMB) receptor model. Diesel burning in vehicular traffic and in the power plants for generator start up was found to be the major contributor to ambient TSP levels at all 10 sites. Other sources with significant contributions were domestic coal burning, vegetative burning (wood combustion and agricultural burns) and refuse open-air burning. Fly ash escaping the electrostatic precipitators of the power plants was a minor contributor to ambient TSP.

  9. Characterization and source apportionment of health risks from ambient PM10 in Hong Kong over 2000-2011

    NASA Astrophysics Data System (ADS)

    Li, Zhiyuan; Yuan, Zibing; Li, Ying; Lau, Alexis K. H.; Louie, Peter K. K.

    2015-12-01

    Atmospheric particulate matter (PM) pollution is a major public health concern in Hong Kong. In this study, the spatiotemporal variations of health risks from ambient PM10 from seven air quality monitoring stations between 2000 and 2011 were analyzed. Positive matrix factorization (PMF) was adopted to identify major source categories of ambient PM10 and quantify their contributions. Afterwards, a point-estimated risk model was used to identify the inhalation cancer and non-cancer risks of PM10 sources. The long-term trends of the health risks from classified local and non-local sources were explored. Furthermore, the reason for the increase of health risks during high PM10 days was discussed. Results show that vehicle exhaust source was the dominant inhalation cancer risk (ICR) contributor (72%), whereas trace metals and vehicle exhaust sources contributed approximately 27% and 21% of PM10 inhalation non-cancer risk (INCR), respectively. The identified local sources accounted for approximately 80% of the ICR in Hong Kong, while contribution percentages of the non-local and local sources for INCR are comparable. The clear increase of ICR at high PM days was mainly attributed to the increase of contributions from coal combustion/biomass burning and secondary sulfate, while the increase of INCR at high PM days was attributed to the increase of contributions from the sources coal combustion/biomass burning, secondary nitrate, and trace metals. This study highlights the importance of health risk-based source apportionment in air quality management with protecting human health as the ultimate target.

  10. Numerical study of atmospheric particulate matters: source apportionment to characterize 3D transport and transformation of precursors and secondary pollutants

    NASA Astrophysics Data System (ADS)

    Wu, Dongwei

    In recent years, Mainland China, and in particular the industrial hotbed of the Pearl River Delta (PRD) has experienced an increasingly serious problem of high concentrations of airborne particulate matter. Following the tightening-up of China's air quality policies in recent years, and with especially fine particles now added to a new air quality objective, the identification of major source regions and major types of pollutants has become critically important. In this study, a source-oriented method (Particulate Source Apportionment Technology: PSAT) implemented in 3-D Comprehensive Air Quality Model (CAMx), has been applied to analyze how different emission activities impact fine particle concentration in the PRD region. By using this method, a detailed source region and emission category contribution matrix is derived for all regions within the Hong Kong/PRD region. Source appointment results shows that, in summer and spring time, emissions inside PRD region are the major fine particle sources, contribution 70.7% (11.2 mug/m3) and 52.5% (13.1 mug/m3) to the total figure. Super-regional transports are found to be significant in autumn and winter, contribution 58.5% (20.2 mug/m3) and 64.6% (27.8 mug/m3) of the total fine particles in PRD and Hong Kong region. Another important cause of high PM levels has been the transport of fine particles between cities within the PRD region, with three different regions selected for detailed analysis. Results show that mobile vehicle and industry emission are the two major sources for fine particles. Meanwhile, over the same period in Hong Kong, marine proved to be another very significant source of particle pollutant in addition to the significant impact from motor vehicle. Results show that for the Hong Kong/PRD region local reduction of mobile sources and collaboration between different areas could have succeeded in alleviating the air pollution problem.

  11. Bioavailability of Polycyclic Aromatic Hydrocarbons and their Potential Application in Eco-risk Assessment and Source Apportionment in Urban River Sediment

    NASA Astrophysics Data System (ADS)

    Yang, Xunan; Yu, Liuqian; Chen, Zefang; Xu, Meiying

    2016-03-01

    Traditional risk assessment and source apportionment of sediments based on bulk polycyclic aromatic hydrocarbons (PAHs) can introduce biases due to unknown aging effects in various sediments. We used a mild solvent (hydroxypropyl-β-cyclodextrin) to extract the bioavailable fraction of PAHs (a-PAHs) from sediment samples collected in Pearl River, southern China. We investigated the potential application of this technique for ecological risk assessments and source apportionment. We found that the distribution of PAHs was associated with human activities and that the a-PAHs accounted for a wide range (4.7%–21.2%) of total-PAHs (t-PAHs), and high risk sites were associated with lower t-PAHs but higher a-PAHs. The correlation between a-PAHs and the sediment toxicity assessed using tubificid worms (r = ‑0.654, P = 0.021) was greater than that from t-PAH-based risk assessment (r = ‑0.230, P = 0.472). Moreover, the insignificant correlation between a-PAH content and mPEC-Q of low molecular weight PAHs implied the potiential bias of t-PAH-based risk assessment. The source apportionment from mild extracted fractions was consistent across different indicators and was in accordance with typical pollution sources. Our results suggested that mild extraction-based approaches reduce the potential error from aging effects because the mild extracted PAHs provide a more direct indicator of bioavailability and fresher fractions in sediments.

  12. Assessment of the sources of suspended particulate matter aerosol using US EPA PMF 3.0.

    PubMed

    Khan, Md Firoz; Hirano, Koichiro; Masunaga, Shigeki

    2012-01-01

    The main purpose of this paper was to carry out a source apportionment of suspended particulate matter (SPM) samples using positive matrix factorization procedure. The central and local Government of Japan introduced strict emission regulations in 2002/10 and 2003/10, respectively, in curbing SPM pollution from major metropolitans. This paper also highlighted the impact of the measures taken by the central and local Government of Japan on the reduction of SPM and the contributions of sources. SPM samples were collected for 6 years starting from 1999 to 2005 at two sites, i.e., site A (urban) and site B (suburban) of Yokohama, Japan. Microwave digestion and inductively coupled plasma-mass spectroscopy (ICP-MS) were employed to measure Mg, Al, Ca, V, Cr, Mn, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Ag, Cd, Cs, Ba, Pb and Bi, while water soluble ions (Na(+), NH₄⁺, K(+), Ca(2+), Mg(2+), Cl(-), NO₃⁻ and SO₄²⁻ as well as carbonaceous mass (EC and OC) were analyzed using ion chromatograph and CHN analyzer, respectively. The sources identified at two sites were automobile, soil dust, marine aerosol, mixed sources, and secondarily formed aerosol. Also, source quantification was performed. Automobile and soil dust were striking contributors at site A. Automobile and soil dust of SPM aerosol might be produced from local origin at current study areas. Besides, Asian dust had an impact on high concentrations of SPM aerosol in some certain period of the year due to the outflows of East Asian emission. In contrast, secondary aerosol in the form of sulfate and ammonium as well as mixed sources (coal, long-transported Cs, and other unknown sources) were remarkable at site B. Stationary/industrial combustion has apparently more impact on the release of SPM components at site B than A. Automobile regulations in 2002 and 2003, respectively, resulted in reduction of SPM by 28% for site A and 16% for site B. There was also net reduction of automobile contribution at both sites due

  13. Natural Radionuclides and Isotopic Signatures for Determining Carbonaceous Aerosol Sources, Aerosol Lifetimes, and Washout Processes

    SciTech Connect

    Gaffney, Jeffrey

    2012-12-12

    This is the final technical report. The project description is as follows: to determine the role of aerosol radiative forcing on climate, the processes that control their atmospheric concentrations must be understood, and aerosol sources need to be determined for mitigation. Measurements of naturally occurring radionuclides and stable isotopic signatures allow the sources, removal and transport processes, as well as atmospheric lifetimes of fine carbonaceous aerosols, to be evaluated.

  14. Use of lead isotopes to identify sources of metal and metalloid contaminants in atmospheric aerosol from mining operations.

    PubMed

    Félix, Omar I; Csavina, Janae; Field, Jason; Rine, Kyle P; Sáez, A Eduardo; Betterton, Eric A

    2015-03-01

    Mining operations are a potential source of metal and metalloid contamination by atmospheric particulate generated from smelting activities, as well as from erosion of mine tailings. In this work, we show how lead isotopes can be used for source apportionment of metal and metalloid contaminants from the site of an active copper mine. Analysis of atmospheric aerosol shows two distinct isotopic signatures: one prevalent in fine particles (<1μm aerodynamic diameter) while the other corresponds to coarse particles as well as particles in all size ranges from a nearby urban environment. The lead isotopic ratios found in the fine particles are equal to those of the mine that provides the ore to the smelter. Topsoil samples at the mining site show concentrations of Pb and As decreasing with distance from the smelter. Isotopic ratios for the sample closest to the smelter (650m) and from topsoil at all sample locations, extending to more than 1km from the smelter, were similar to those found in fine particles in atmospheric dust. The results validate the use of lead isotope signatures for source apportionment of metal and metalloid contaminants transported by atmospheric particulate. PMID:25496740

  15. Use of Lead Isotopes to Identify Sources of Metal and Metalloid Contaminants in Atmospheric Aerosol from Mining Operations

    PubMed Central

    Félix, Omar I.; Csavina, Janae; Field, Jason; Rine, Kyle P.; Sáez, A. Eduardo; Betterton, Eric A.

    2014-01-01

    Mining operations are a potential source of metal and metalloid contamination by atmospheric particulate generated from smelting activities, as well as from erosion of mine tailings. In this work, we show how lead isotopes can be used for source apportionment of metal and metalloid contaminants from the site of an active copper mine. Analysis of atmospheric aerosol shows two distinct isotopic signatures: one prevalent in fine particles (< 1 μm aerodynamic diameter) while the other corresponds to coarse particles as well as particles in all size ranges from a nearby urban environment. The lead isotopic ratios found in the fine particles are equal to those of the mine that provides the ore to the smelter. Topsoil samples at the mining site show concentrations of Pb and As decreasing with distance from the smelter. Isotopic ratios for the sample closest to the smelter (650 m) and from topsoil at all sample locations, extending to more than 1 km from the smelter, were similar to those found in fine particles in atmospheric dust. The results validate the use of lead isotope signatures for source apportionment of metal and metalloid contaminants transported by atmospheric particulate. PMID:25496740

  16. The source apportionment of polycyclic aromatic hydrocarbons (PAHs) in the topsoil in Xiaodian sewage irrigation area, North of China.

    PubMed

    Li, Jia-Le; Wang, Yan-Xin; Zhang, Cai-Xiang; Dong, Yi-Hui; Du, Bin; Liao, Xiao-Ping

    2014-12-01

    31 topsoil samples were collected by grid method in Xiaodian sewage irrigation area, Taiyuan City, North of China. The concentrations of 16 kinds of polycyclic aromatic hydrocarbons (PAHs) were determined by gas chromatograph coupled with mass spectrum. Generally speaking, the distribution order of PAHs in the area is: those with five and six rings > those with four rings > those with two and three rings. Source apportionment shows a significant zonation of the source of PAHs: the civil coal pollution occurred in the north part, the local and far factory pollution happened in the middle area and the mixed pollution sources from coal and wood combustion, automotive emission, presented in the south area. The distribution of PAHs has a definite relationship with the sewage water flow and soil adsorption. The related coefficient between PAHs and physicochemical property showed there was a negative correlation between pH, silt, clay and PAHs while there was a positive correlation between total organic carbon, sand and PAHs. PMID:25139034

  17. PM2.5 source apportionment in Lombardy (Italy): Comparison of receptor and chemistry-transport modelling results

    NASA Astrophysics Data System (ADS)

    Pirovano, G.; Colombi, C.; Balzarini, A.; Riva, G. M.; Gianelle, V.; Lonati, G.

    2015-04-01

    This work discusses the source apportionment results produced by receptor and chemistry-transport modelling for PM2.5 in Northern Italy, selected as case study due to its very critical conditions. Receptor modelling was performed using the Chemical Mass Balance model, while source oriented analysis by means of the CAMx chemistry transport model. Models shared the same source profiles, mostly based on local data. CMB showed a better reconstruction of the mass closure, while CAMx systematically underestimated cold season concentrations. Nevertheless both models provided the same source ranking at several receptors. According to CMB results, the most relevant contributions during the cold season, ranging around 10 μg m-3, were yielded by road transport, domestic heating and ammonium nitrate. CAMx provided similar results for the secondary sources, while systematically underestimated road transport and domestic heating. A similar behaviour was observed during the summer season. The main discrepancies between the models were: the questionable results from CMB at some receptors, missing the road transport contribution, clearly pointed out by CAMx/PSAT; the ability of CAMx/PSAT to apportion the contribution of sources sharing similar profiles and strongly correlated such as CI and SI vehicles, altogether recognized as traffic source by CMB; the ability of CAMx/PSAT to identify the contribution of secondary PM deriving from complex chemical transformation, such as anthropogenic and biogenic SOA. Finally, the comparison of specific source contribution pointed out that CAMx missed the reconstruction of the road transport contribution to the OC, mostly as a consequence of deficiencies in the emission inventories concerning the primary OC in the cold season and the concurrent underestimation of emissions and secondary OC formation in the warm season.

  18. Source Apportionment of Particulate Matter Collected Upwind and Downwind of a Steel Facility in Granite City, IL (USA)

    NASA Astrophysics Data System (ADS)

    Duvall, R. M.; Norris, G. A.; Willis, R. D.; Turner, J. R.; Kaleel, R.; Sweitzer, T.; Preston, B.; Hays, M. D.

    2009-04-01

    St. Louis is currently in nonattainment of the annual PM2.5 National Ambient Air Quality Standard (NAAQS). Granite City Steel Works (GSCW), located in Granite City, IL is considered to be a significant source impacting the St. Louis area and the largest PM2.5 point source contributor. Twelve grab samples were collected in and around the steel facility including the basic oxygen furnace, steel and iron slag crushing, coal pulverizing, baghouse dust, paved road dust, and unpaved road dust. The bulk samples were resuspended in a resuspension chamber using a PM2.5 cutpoint and collected on Teflon, quartz and polycarbonate filters. Fine particulate matter (PM) samples (12-hr and 24-hr) were collected upwind and downwind of GSCW from October 13 to December 13, 2007 to identify sources contributing to nonattainment in St. Louis. The samples were analyzed for trace metals (X-Ray Fluorescence), ions (Ion Chromatography), elemental and organic carbon (thermal optical analysis), and organic species (solvent extraction Gas Chromatography/Mass Spectrometry). Source apportionment was conducted using the EPA Chemical Mass Balance (CMB) Model (v 8.2). Major sources impacting the 12-hr samples included the blast oxygen furnace, secondary sulfate, and road dust. Higher excess steel and coke works contributions were associated with higher wind speeds (greater than 5 mph) and more variability in source impacts was observed. Major sources impacting the 24-hr samples included secondary sulfate and motor vehicles (diesel and gasoline). Contributions were similar between the coke and steel works sources. Disclaimer: Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

  19. Source apportionment of polycyclic aromatic hydrocarbons in PM2.5 using positive matrix factorization modeling in Shanghai, China.

    PubMed

    Wang, Fengwen; Lin, Tian; Feng, Jialiang; Fu, Huaiyu; Guo, Zhigang

    2015-01-01

    Providing quantitative information on the sources of PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) in urban regions is vital to establish effective abatement strategies for air pollution in a megacity. In this study, based on a year data set from October 2011 to August 2012, the sources of PM2.5-bound 16 USEPA priority PAHs (16 PAHs) in Shanghai, a megacity in China, were apportioned by positive matrix factorization (PMF) modeling. The average concentrations (in ng m(-3)) of 16 PAHs in PM2.5 in the fall, winter, spring and summer were 20.5 ± 18.2, 27.2 ± 24.0, 13.7 ± 7.7 and 6.4 ± 8.1, respectively, with an annual average of 16.9 ± 9.0. The source apportionment by PMF indicated that coal burning (30.5%) and gasoline engine emission (29.0%) were the two major sources of PAHs in the PM2.5 in Shanghai, followed by diesel engine emission (17.5%), air-surface exchange (11.9%) and biomass burning (11.1%). The highest source contributor for PAHs in the fall and winter was gasoline engine emission (36.7%) and coal burning (41.9%), respectively; while in the spring and summer, it was diesel engine emission that contributed the most (52.1% and 43.5%, respectively). It was suggested that there was a higher contribution of PAHs from engine emissions in 2011-2012 compared with those in 2002-2003. The major sources apportioned by PMF complemented well with this of using diagnostic ratios, suggesting a convincing identification of sources for the PM2.5-bound 16 PAHs in a megacity. PMID:25493422

  20. Levels and source apportionment of children's lead exposure: could urinary lead be used to identify the levels and sources of children's lead pollution?

    PubMed

    Cao, Suzhen; Duan, Xiaoli; Zhao, Xiuge; Wang, Beibei; Ma, Jin; Fan, Delong; Sun, Chengye; He, Bin; Wei, Fusheng; Jiang, Guibin

    2015-04-01

    As a highly toxic heavy metal, the pollution and exposure risks of lead are of widespread concern for human health. However, the collection of blood samples for use as an indicator of lead pollution is not always feasible in most cohort or longitudinal studies, especially those involving children health. To evaluate the potential use of urinary lead as an indicator of exposure levels and source apportionment, accompanying with environmental media samples, lead concentrations and isotopic measurements (expressed as (207)Pb/(206)Pb, (208)Pb/(206)Pb and (204)Pb/(206)Pb) were investigated and compared between blood and urine from children living in the vicinities of a typical coking plant and lead-acid battery factory. The results showed urinary lead might not be a preferable proxy for estimating blood lead levels. Fortunately, urinary lead isotopic measurements could be used as an alternative for identifying the sources of children's lead exposure, which coincided well with the blood lead isotope ratio analysis. PMID:25617855

  1. Development and evaluation of a daily temporal interpolation model for fine particulate matter species concentrations and source apportionment

    NASA Astrophysics Data System (ADS)

    Redman, Jeremiah D.; Holmes, Heather A.; Balachandran, Sivaraman; Maier, Marissa L.; Zhai, Xinxin; Ivey, Cesunica; Digby, Kyle; Mulholland, James A.; Russell, Armistead G.

    2016-09-01

    The impacts of emissions sources on air quality in St. Louis, Missouri are assessed for use in acute health effects studies. However, like many locations in the United States, the speciated particulate matter (PM) measurements from regulatory monitoring networks in St. Louis are only available every third day. The power of studies investigating acute health effects of air pollution is reduced when using one-in-three day source impacts compared to daily source impacts. This paper presents a temporal interpolation model to estimate daily speciated PM2.5 mass concentrations and source impact estimates using one-in-three day measurements. The model is used to interpolate 1-in-3 day source impact estimates and to interpolate the 1-in-3 day PM species concentrations prior to source apportionment (SA). Both approaches are compared and evaluated using two years (June 2001-May 2003) of daily data from the St. Louis Midwest Supersite (STL-SS). Data withholding is used to simulate a 1-in-3 day data set from the daily data to evaluate interpolated estimates. After evaluation using the STL-SS data, the model is used to estimate daily source impacts at another site approximately seven kilometers (7 km) northwest of the STL-SS (Blair); results between the sites are compared. For interpolated species concentrations, the model performs better for secondary species (sulfate, nitrate, ammonium, and organic carbon) than for primary species (metals and elemental carbon), likely due to the greater spatial autocorrelation of secondary species. Pearson correlation (R) values for sulfate, nitrate, ammonium, elemental carbon, and organic carbon ranged from 0.61 (elemental carbon, EC2) to 0.97 (sulfate). For trace metals, the R values ranged from 0.31 (Ba) to 0.81 (K). The interpolated source impact estimates also indicated a stronger correlation for secondary sources. Correlations of the secondary source impact estimates based on measurement data and interpolation data ranged from 0.68 to 0

  2. Source apportionment of PM 2.5: Comparing PMF and CMB results for four ambient monitoring sites in the southeastern United States

    NASA Astrophysics Data System (ADS)

    Lee, Sangil; Liu, Wei; Wang, Yuhang; Russell, Armistead G.; Edgerton, Eric S.

    2008-06-01

    Two commonly used receptor models, positive matrix factorization (PMF) and chemical mass balance (CMB), are applied to 3-year PM2.5 data at two urban sites (Atlanta, GA and Birmingham, AL) and two rural sites (Yorkville, GA and Centreville, AL). Source apportionment results using the two receptor models are analyzed and compared. Both models are able to identify major sources at all sites, though the degree of agreements and correlations between source impacts estimated by PMF and CMB varies depending on sources and receptor sites. Estimated contributions of secondary inorganic particles are the most comparable and highly correlated. The lesser comparability and correlations of estimated contributions of other sources (mostly primary) may be attributed to several factors. Resolved source profiles in PMF have more processed (or aged) characteristics resulting in part from atmospheric mixing and condensation of oxidized compounds, whereas source profiles used in CMB are obtained from measurements of emission sources with minimum amount of atmospheric processing. The PMF profiles vary from site to site; both atmospheric processing and local source variability contribute. In comparison, the CMB profiles obtained from a limited number of emission measurements may not be locally representative even if they are regionally representative. The omission of possible known or unknown sources due to lack of proper source profiles or proper "marker" species may also cause the differences in the source apportionment results. In addition, the implication for PM time-series health study is discussed based on the results from this study.

  3. Integrated Analyses of Multiple Worldwide Aerosol Mass Spectrometer Datasets for Improved Understanding of Aerosol Sources and Processes and for Comparison with Global Models

    SciTech Connect

    Zhang, Qi; Jose, Jimenez Luis

    2014-04-28

    The AMS is the only current instrument that provides real-time, quantitative, and size-resolved data on submicron non-refractory aerosol species with a time resolution of a few minutes or better. The AMS field data are multidimensional and massive, containing extremely rich information on aerosol chemistry, microphysics and dynamics—basic information that is required to evaluate and quantify the radiative climate forcing of atmospheric aerosols. The high time resolution of the AMS data also reveals details of aerosol dynamic variations that are vital to understanding the physico-chemical processes of atmospheric aerosols that govern aerosol properties relevant to the climate. There are two primary objectives of this 3-year project. Our first objective is to perform highly integrated analysis of dozens of AMS datasets acquired from various urban, forested, coastal, marine, mountain peak, and rural/remote locations around the world and synthesize and inter-compare results with a focus on the sources and the physico-chemical processes that govern aerosol properties relevant to aerosol climate forcing. Our second objective is to support our collaboration with global aerosol modelers, in which we will supply the size-resolved aerosol composition and temporal variation data (via a public web interface) and our analysis results for use in model testing and validation and for translation of the rich AMS database into model constraints that can improve climate forcing simulations. Several prominent global aerosol modelers have expressed enthusiastic support for this collaboration. The specific tasks that we propose to accomplish include 1) to develop, validate, and apply multivariate analysis techniques for improved characterization and source apportionment of organic aerosols; 2) to evaluate aerosol source regions and relative contributions based on back-trajectory integration (PSCF method); 3) to summarize and synthesize submicron aerosol information, including

  4. Chemical composition, sources, and aging process of submicron aerosols in Beijing: Contrast between summer and winter

    NASA Astrophysics Data System (ADS)

    Hu, Weiwei; Hu, Min; Hu, Wei; Jimenez, Jose L.; Yuan, Bin; Chen, Wentai; Wang, Ming; Wu, Yusheng; Chen, Chen; Wang, Zhibin; Peng, Jianfei; Zeng, Limin; Shao, Min

    2016-02-01

    To investigate the seasonal characteristics of submicron aerosol (PM1) in Beijing urban areas, a high-resolution time-of-flight aerosol-mass-spectrometer (HR-ToF-AMS) was utilized at an urban site in summer (August to September 2011) and winter (November to December 2010), coupled with multiple state of the art online instruments. The average mass concentrations of PM1 (60-84 µg m-3) and its chemical compositions in different campaigns of Beijing were relatively consistent in recent years. In summer, the daily variations of PM1 mass concentrations were stable and repeatable. Eighty-two percent of the PM1 mass concentration on average was composed of secondary species, where 62% is secondary inorganic aerosol and 20% secondary organic aerosol (SOA). In winter, PM1 mass concentrations changed dramatically because of the different meteorological conditions. The high average fraction (58%) of primary species in PM1 including primary organic aerosol (POA), black carbon, and chloride indicates primary emissions usually played a more important role in the winter. However, aqueous chemistry resulting in efficient secondary formation during occasional periods with high relative humidity may also contribute substantially to haze in winter. Results of past OA source apportionment studies in Beijing show 45-67% of OA in summer and 22-50% of OA in winter can be composed of SOA. Based on the source apportionment results, we found 45% POA in winter and 61% POA in summer are from nonfossil sources, contributed by cooking OA in both seasons and biomass burning OA (BBOA) in winter. Cooking OA, accounting for 13-24% of OA, is an important nonfossil carbon source in all years of Beijing and should not be neglected. The fossil sources of POA include hydrocarbon-like OA from vehicle emissions in both seasons and coal combustion OA (CCOA) in winter. The CCOA and BBOA were the two main contributors (57% of OA) for the highest OA concentrations (>100 µg m-3) in winter. The POA

  5. Semicontinuous GC analysis and receptor modelling for source apportionment of ozone precursor hydrocarbons in Bresso, Milan, 2003.

    PubMed

    Latella, A; Stani, G; Cobelli, L; Duane, M; Junninen, H; Astorga, C; Larsen, B R

    2005-04-15

    The European Ozone Directive 2002/3/EC specifies the analysis of 30 individual C2-C9 hydrocarbons in urban air with the attribution of emission sources to pollution concentrations as a major objective. In the present study, we investigate an approach for source apportionment of these ozone precursor hydrocarbons in urban air based on reliable semi continuous volatile organic compound (VOC) analysis in the field and in vehicle emission laboratory combined with multivariate receptor modeling. The GC system relies on an hourly analytical cycle based on a trap sample enrichment phase followed by a dual column gas chromatographic flame ionisation detector (FID) analysis and has successfully been tested during an air monitoring campaign at an urban site (Milan, Italy, September 2003) and in the vehicle laboratory performing exhaust emission measurements while running driving cycles on a chassis dynamometer (mopeds, gasoline and diesel cars). The receptor modeling relies on two complementary principles. The chemical mass balance (CMB) modeling apportions well characterized source profiles for the 30 individual C2-C9 hydrocarbons in the Ozone Directive to the concentrations in ambient air and produces source contribution estimates (SCE) as output. The positive matrix factorization (PMF) analyses variability in the ambient air concentration data and searches for latent variables consisting of co-varying hydrocarbons and produces profiles as output, which in this study could be attributed to known emission sources. Both CMB and PMF rely on an estimated uncertainty for each input data. A new approach is presented, by which the uncertainty is allowed to float as function of the photochemical reactivity of the atmosphere and the stability of each individual compound. PMID:15865170

  6. Characterization of PM2.5 in Guangzhou, China: uses of organic markers for supporting source apportionment.

    PubMed

    Wang, Jingzhi; Ho, Steven Sai Hang; Ma, Shexia; Cao, Junji; Dai, Wenting; Liu, Suixin; Shen, Zhenxing; Huang, Rujin; Wang, Gehui; Han, Yongming

    2016-04-15

    Organic carbon (OC), elemental carbon (EC), and non-polar organic compounds including n-alkanes (n-C14-n-C40), polycyclic aromatic hydrocarbons (PAHs), phthalate esters (PAEs) and hopanes were quantified in fine particulate (PM2.5), which were collected in urban area of Guangzhou, China in winter and summer in 2012/2013. The pollutants levels were well comparable with the data obtained in previous studies in Pearl River Delta (PRD) region but much lower than most northern Chinese megacities. The contribution of EC to PM2.5 and OC/EC ratio suggest that the pollution sources were relatively consistent in GZ between the two seasons. Benzo[a]pyrene (BaP) was the most abundant PAHs, which were 4.9 and 1.0ng/m(3) on average, accounting for 10.7% and 9.1% to the total quantified PAHs in winter and summer, respectively. The total concentrations of PAEs ranged from 289.1 to 2435ng/m(3) and from 102.4 to 1437ng/m(3), respectively, in winter and summer. Di-n-butyl phthalate (DBP) was the most dominant PAEs. The ambient levels of PAEs could be partly attributed to the widespread uses of the household products, municipal garbage compressing, sewage, and external painting material on the building. Source apportionment for OC with chemical mass balance (CMB) model demonstrated coal combustion, vehicle emission, cooking, and secondary organic compounds (SOC) formation were the four major pollution sources. Both of the indices of n-alkanes and diagnostic PAHs ratios support that anthropogenic sources such as vehicle emission and coal combustion were the significant pollution sources with some extents from epicuticular waxes by terrestrial plants. The ratio of hopanes to EC proved the influences from vehicle emission, and displayed a certain degree of the air aging in the Guangzhou ambient air. PMID:26851882

  7. Radiocarbon analysis of elemental and organic carbon in Switzerland during winter-smog episodes from 2008 to 2012 - Part 1: Source apportionment and spatial variability

    NASA Astrophysics Data System (ADS)

    Zotter, P.; Ciobanu, V. G.; Zhang, Y. L.; El-Haddad, I.; Macchia, M.; Daellenbach, K. R.; Salazar, G. A.; Huang, R.-J.; Wacker, L.; Hueglin, C.; Piazzalunga, A.; Fermo, P.; Schwikowski, M.; Baltensperger, U.; Szidat, S.; Prévôt, A. S. H.

    2014-06-01

    While several studies have investigated winter-time air pollution with a wide range of concentration levels, hardly any results are available for longer time periods covering several winter-smog episodes at various locations; e.g. often only a few weeks from a single winter are investigated. Here, we present source apportionment results of winter-smog episodes from 16 air pollution monitoring stations across Switzerland from five consecutive winters. Radiocarbon (14C) analyses of the elemental (EC) and organic (OC) carbon fractions, as well as levoglucosan, major water-soluble ionic species and gas-phase pollutant measurements were used to characterize the different sources of PM10. The most important contributions to PM10 during winter-smog episodes in Switzerland were on average the secondary inorganic constituents (sum of nitrate, sulfate and ammonium = 41 ± 15%) followed by organic matter OM (30 ± 12%) and EC (5 ± 2%). The non-fossil fractions of OC (fNF,OC) ranged on average from 69-85% and 80-95 % for stations north and south of the Alps, respectively, showing that traffic contributes on average only up to ~30% to OC. The non-fossil fraction of EC (fNF,EC), entirely attributable to primary biomass burning, was on average 42 ± 13% and 49 ± 15% for north and south of the Alps, respectively. While a high correlation was observed between fossil EC and nitrogen oxides, both primarily emitted by traffic, these species did not significantly correlate with fossil OC (OCF), which seems to suggest that a considerable amount of OCF is secondary, formed from fossil precursors. Elevated fNF,EC and fNF,OC values and the high correlation of the latter with other wood burning markers, including levoglucosan and water soluble potassium (K+) indicate that biomass burning is the major source of carbonaceous aerosols during winter-smog episodes in Switzerland. The inspection of the non-fossil OC and EC levels and the relation with levoglucosan and water-soluble K+ shows

  8. Radiocarbon analysis of elemental and organic carbon in Switzerland during winter-smog episodes from 2008 to 2012 - Part 1: Source apportionment and spatial variability

    NASA Astrophysics Data System (ADS)

    Zotter, P.; Ciobanu, V. G.; Zhang, Y. L.; El-Haddad, I.; Macchia, M.; Daellenbach, K. R.; Salazar, G. A.; Huang, R.-J.; Wacker, L.; Hueglin, C.; Piazzalunga, A.; Fermo, P.; Schwikowski, M.; Baltensperger, U.; Szidat, S.; Prévôt, A. S. H.

    2014-12-01

    While several studies have investigated winter-time air pollution with a wide range of concentration levels, hardly any results are available for longer time periods covering several winter-smog episodes at various locations; e.g., often only a few weeks from a single winter are investigated. Here, we present source apportionment results of winter-smog episodes from 16 air pollution monitoring stations across Switzerland from five consecutive winters. Radiocarbon (14C) analyses of the elemental (EC) and organic (OC) carbon fractions, as well as levoglucosan, major water-soluble ionic species and gas-phase pollutant measurements were used to characterize the different sources of PM10. The most important contributions to PM10 during winter-smog episodes in Switzerland were on average the secondary inorganic constituents (sum of nitrate, sulfate and ammonium = 41 ± 15%) followed by organic matter (OM) (34 ± 13%) and EC (5 ± 2%). The non-fossil fractions of OC (fNF,OC) ranged on average from 69 to 85 and 80 to 95% for stations north and south of the Alps, respectively, showing that traffic contributes on average only up to ~ 30% to OC. The non-fossil fraction of EC (fNF,EC), entirely attributable to primary wood burning, was on average 42 ± 13 and 49 ± 15% for north and south of the Alps, respectively. While a high correlation was observed between fossil EC and nitrogen oxides, both primarily emitted by traffic, these species did not significantly correlate with fossil OC (OCF), which seems to suggest that a considerable amount of OCF is secondary, from fossil precursors. Elevated fNF,EC and fNF,OC values and the high correlation of the latter with other wood burning markers, including levoglucosan and water soluble potassium (K+) indicate that residential wood burning is the major source of carbonaceous aerosols during winter-smog episodes in Switzerland. The inspection of the non-fossil OC and EC levels and the relation with levoglucosan and water-soluble K

  9. Spatial variability of carbonaceous aerosols and associated source tracers in two cites in the Midwestern United States

    NASA Astrophysics Data System (ADS)

    Snyder, David C.; Rutter, Andrew P.; Worley, Chris; Olson, Mike; Plourde, Anthony; Bader, Rebecca C.; Dallmann, Timothy; Schauer, James J.

    2010-05-01

    Semi-continuous and 24-h averaged measurements of fine carbonaceous aerosols were made concurrently at three sites within each of two U.S. Midwestern Cities; Detroit, Michigan and Cleveland, Ohio; during two, one-month intensive campaigns conducted in July of 2007 and January & February of 2008. A comparison of 24-h measurements revealed substantial intra-urban variability in carbonaceous aerosols consistent with the influence of local sources, and excesses in both PM 2.5 organic carbon (OC) and elemental carbon (EC) were identified at individual sites within each city. High time-resolved black carbon (BC) measurements indicated that elemental carbon concentrations were higher at sites adjacent to freeways and busy surface streets, and temporal patterns suggested that excess EC at sites adjacent to freeways was dominated by mobile source emissions while excesses in EC away from traffic corridors was dominated by point/area source emissions. The site-to-site variability in OC concentrations was approximately 7% within the neighborhood scale (0.5-4 km) and between 4 and 27% at the urban scale (4-100 km). In contrast, measurements of organic source tracers, in conjunction with a Chemical Mass Balance (CMB) source-apportionment model, indicated that the spatial variation in the contribution of both mobile and stationary sources to PM 2.5 OC often exceeded the variation in OC mass concentration by a factor of 3 or more. Markers for mobile sources, biomass smoke, natural gas, and coal combustion differed by as much as 60% within the neighborhood scale and by greater than 200% within the urban scale. The observations made during this study suggest that the urban excess of carbonaceous aerosols is much more complex than has been previously reported and that a more rigorous, source-oriented approach should be taken in order to assess the risk associated with exposure to carbonaceous aerosols within the industrialized environments of the Midwestern United States.

  10. Measurements and source apportionment of particle-associated polycyclic aromatic hydrocarbons in ambient air in Riyadh, Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Bian, Qijing; Alharbi, Badr; Collett, Jeffrey; Kreidenweis, Sonia; Pasha, Mohammad J.

    2016-07-01

    Ambient air samples were obtained in Riyadh, the capital and largest city of Saudi Arabia, during two measurement campaigns spanning September 2011 to September 2012. Sixteen particle-phase polycyclic aromatic hydrocarbons (PAH) were quantified in 167 samples. Pyrene and fluoranthene were the most abundant PAH, with average of 3.37 ± 14.01 ng m-3 and 8.00 ± 44.09 ng m-3, respectively. A dominant contribution from low molecular weight (LMW) PAH (MW < 228) suggested a large influence of industrial emissions on PAH concentrations. Monte Carlo source apportionment using diagnostic ratios showed that 80 ± 10% of the average LMW PAH concentrations were contributed by petroleum vapor emissions, while 53 ± 19% of high molecular weight (HMW) PAH were from solid fuel combustion emissions. The positive matrix factorization model estimated that oil combustion emissions dominated total PAH concentrations, accounting for on average 96%, likely due to widespread use of oil fuels in energy production (power plants and industries). Our results demonstrate the significant influence of petroleum product production and consumption on particulate-phase PAH concentrations in Riyadh, but also point to the importance of traffic and solid fuel burning, including coke burning and seasonal biomass burning, especially as they contribute to the ambient levels of HMW PAH.

  11. Measurement and apportionment of radon source terms for modeling indoor environments. Final progress report, March 1990--August 1992

    SciTech Connect

    Harley, N.H.

    1992-12-31

    During the present 2 1/2 year contract period, we have made significant Progress in modeling the source apportionment of indoor {sup 222}Rn and in {sup 222}Rn decay product dosimetry. Two additional areas were worked on which we believe are useful for the DOE Radon research Program. One involved an analysis of the research house data, grouping the hourly house {sup 222}Rn measurements into 2 day, 7 day and 90 day intervals to simulate the response of passive monitors. Another area requiring some attention resulted in a publication of 3 years of our indoor/outdoor measurements in a high-rise apartment. Little interest has been evinced in apartment measurements yet 20% of the US population lives in multiple-family dwellings, not in contact with the ground. These data together with a summary of all other published data on apartments showed that apartments have only about 50% greater {sup 222}Rn concentration than the measured outdoor {sup 222}Rn. Apartment dwellers generally represent a low risk group regarding {sup 222}Rn exposure. The following sections describe the main projects in some detail.

  12. Physically constrained source apportionment (PCSA) for polycyclic aromatic hydrocarbon using the Multilinear Engine 2-species ratios (ME2-SR) method.

    PubMed

    Liu, Gui-Rong; Shi, Guo-Liang; Tian, Ying-Ze; Wang, Yi-Nan; Zhang, Cai-Yan; Feng, Yin-Chang

    2015-01-01

    An improved physically constrained source apportionment (PCSA) technology using the Multilinear Engine 2-species ratios (ME2-SR) method was proposed and applied to quantify the sources of PM10- and PM2.5-associated polycyclic aromatic hydrocarbons (PAHs) from Chengdu in winter time. Sixteen priority PAH compounds were detected with mean ΣPAH concentrations (sum of 16 PAHs) ranging from 70.65 ng/m(3) to 209.58 ng/m(3) and from 59.17 ng/m(3) to 170.64 ng/m(3) for the PM10 and PM2.5 samples, respectively. The ME2-SR and positive matrix factorization (PMF) models were employed to estimate the source contributions of PAHs, and these estimates agreed with the experimental results. For the PMF model, the highest contributor to the ΣPAHs was vehicular emission (81.69% for PM10, 82.06% for PM2.5), followed by coal combustion (12.68%, 12.11%), wood combustion (5.65%, 4.45%) and oil combustion (0.72%, 0.88%). For the ME2-SR method, the highest contributions were from diesel (43.19% for PM10, 47.17% for PM2.5) and gasoline exhaust (34.94%, 32.44%), followed by wood combustion (8.79%, 6.37%), coal combustion (12.46%, 12.37%) and oil combustion (0.80%, 1.22%). However, the PAH ratios calculated for the factors extracted by ME2-SR were closer to the values from actual source profiles, implying that the results obtained from ME2-SR might be physically constrained and satisfactory. PMID:25240101

  13. Characteristics and source apportionment of VOCs measured in an industrial area of Nanjing, Yangtze River Delta, China

    NASA Astrophysics Data System (ADS)

    An, Junlin; Zhu, Bin; Wang, Honglei; Li, Yongyu; Lin, Xu; Yang, Hui

    2014-11-01

    Based on the data of volatile organic compounds (VOCs) collected continuously in the Nanjing industrial area, the VOCs temporal variability, photochemical reactivity, differences in tracer ratios, and source apportionment by principal component analysis/absolute principal component scores (PCA/APCS) were analyzed. The results showed that the total VOC concentration was 43.5 ppbv, which was 45.1% alkanes, 25.3% alkenes, 7.3% alkynes and 22.3% aromatics. There was an obvious seasonal variation in the of VOCs, with a maximum in summer and minimum in winter, as well as in the VOC components, with alkanes and alkynes highest in winter, alkenes highest in summer, and aromatics highest in spring. The VOCs exhibited significant diurnal variations, i.e. high at night and low during the day. The concentrations of nighttime VOCs were highest to lowest as follows: summer > autumn > spring > winter. By contrast, the concentrations of daytime VOCs were highest to lowest as follows: winter > summer > spring > autumn. The diurnal variation of the VOCs was the largest in autumn and the smallest in winter. The largest diurnal variation of alkanes and alkenes occurred in autumn, whereas the largest diurnal variation of aromatics and alkynes occurred in spring. Using the propylene-equivalent method, alkenes had the highest concentration, followed by aromatics and alkanes. The ratios of T/B, E/B and X/B were 1.2, 1.0 and 0.8, respectively, possibly due to the aging air mass. Based on the specific pollutant ratio method, the observation site was greatly affected by the surrounding industrial areas. The source analysis of the VOCs in the PCA/APCS mode showed that the sources consisted of industrial production sources, automobile emission sources, combustion sources, industrial production volatilization sources, solvent use sources and biogenic emission sources; in addition, there were seasonal variations. Overall, the sources related to industrial production activities accounted for 45

  14. ATMOSPHERIC AEROSOL SOURCE-RECEPTOR RELATIONSHIPS: THE ROLE OF COAL-FIRED POWER PLANTS

    SciTech Connect

    Allen L. Robinson; Spyros N. Pandis; Cliff I. Davidson

    2004-12-01

    This report describes the technical progress made on the Pittsburgh Air Quality Study (PAQS) during the period of March 2004 through August 2004. Significant progress was made this project period on the analysis of ambient data, source apportionment, and deterministic modeling activities. Results highlighted in this report include evaluation of the performance of PMCAMx+ for an air pollution episode in the Eastern US, an emission profile for a coke production facility, ultrafine particle composition during a nucleation event, and a new hybrid approach for source apportionment. An agreement was reached with a utility to characterize fine particle and mercury emissions from a commercial coal fired power. Research in the next project period will include source testing of a coal fired power plant, source apportionment analysis, emission scenario modeling with PMCAMx+, and writing up results for submission as journal articles.

  15. Aerosol nitrate from lightning - from sources to impacts

    NASA Astrophysics Data System (ADS)

    Tost, Holger

    2016-04-01

    Particulate nitrate is a key component on the inorganic atmospheric aerosol composition. Due to its semi-volatility, an accurate description of the budget and the impacts of nitrate aerosol are still somewhat uncertain. To address some of the impacts of nitrate, in this study we explicitly analyse the impact of aerosol nitrate from a natural source, namely lightning. As the lightning NOx emissions are only a contribution to the total NOx emissions, this example does not resemble a typical annihilation scenario, which might substantially misjudge the effect of aerosol nitrate due to the high non-linearity in the nitrate budget, but also other directly connected compounds, but tries to shed light onto the sensitivity of aerosol nitrate and its effects. On the other hand, lightning represents an emission source of NOx, which is partly injected directly in the upper troposphere, where due to its longer lifetime and the temperature dependent stability of NH4NO3 aerosol nitrate can form much easier and has a longer lifetime against decomposition. This study uses a comprehensive chemistry climate model to track the evolution of aerosol nitrate from the lightning NOx emission, via chemical processing and gas-aerosol partitioning, aerosol microphyiscal processes down to the climatic impacts of the nitrate aerosol particles via direct aerosol-radiation and aerosol-cloud interactions. All of these processes are explicitly considered with the help of state-of-the-art (parameterisation) schemes, including a comprehensive multi-phase chemistry configuration, a microphysical and chemical composition aerosol model, aerosol optical properties and a two-moment cloud microphysical scheme with explicit activation of aerosol particles into cloud droplets and the consideration of aerosol particles in ice formation processes. Furthermore, some uncertainty with respect to cloud droplet formation has been considered by using two different aerosol activation schemes. To estimate the

  16. An Analysis of EPA’s STAR Program and a Decade of Field Changing Research in Atmospheric Aerosols

    EPA Science Inventory

    A number of studies in the past decade have transformed the way we think about atmospheric aerosols. The advances include, but are not limited to, source apportionment of organics using aerosol mass spectrometer data, the volatility basis set approach, quantifying isoprene oxida...

  17. Characterization of polar organic compounds and source analysis of fine organic aerosols in Hong Kong

    NASA Astrophysics Data System (ADS)

    Li, Yunchun

    Organic aerosols, as an important fraction of airborne particulate mass, significantly affect the environment, climate, and human health. Compared with inorganic species, characterization of individual organic compounds is much less complete and comprehensive because they number in thousands or more and are diverse in chemical structures. The source contributions of organic aerosols are far from being well understood because they can be emitted from a variety of sources as well as formed from photochemical reactions of numerous precursors. This thesis work aims to improve the characterization of polar organic compounds and source apportionment analysis of fine organic carbon (OC) in Hong Kong, which consists of two parts: (1) An improved analytical method to determine monocarboxylic acids, dicarboxylic acids, ketocarboxylic acids, and dicarbonyls collected on filter substrates has been established. These oxygenated compounds were determined as their butyl ester or butyl acetal derivatives using gas chromatography-mass spectrometry. The new method made improvements over the original Kawamura method by eliminating the water extraction and evaporation steps. Aerosol materials were directly mixed with the BF 3/BuOH derivatization agent and the extracting solvent hexane. This modification improves recoveries for both the more volatile and the less water-soluble compounds. This improved method was applied to study the abundances and sources of these oxygenated compounds in PM2.5 aerosol samples collected in Hong Kong under different synoptic conditions during 2003-2005. These compounds account for on average 5.2% of OC (range: 1.4%-13.6%) on a carbon basis. Oxalic acid was the most abundant species. Six C2 and C3 oxygenated compounds, namely oxalic, malonic, glyoxylic, pyruvic acids, glyoxal, and methylglyoxal, dominated this suite of oxygenated compounds. More efforts are therefore suggested to focus on these small compounds in understanding the role of oxygenated

  18. On the Aerosol Source Livestock Raising

    NASA Astrophysics Data System (ADS)

    Schneider, F. E.; Brüggemann, E.; Gnauk, T.; Lammel, G.; Müller, F.; Plewka, A.; Röhrl, A.; Wieser, P. H.

    2002-12-01

    Agriculture is a prime stakeholder in the atmospheric and climate changes as on one hand side it will be strongly affected by a changing climate and yet is today by air pollution while on the other hand, through her emissions agriculture is also driving these changes. Particulate matter is important for air pollution / human health. Very little is known about the mass flux and composition of the particulate matter emitted from livestock farming. We report on the design and results of a pilot study investigating the aerosol source livestock farming undertaken at the experimental farm Talgut Lindenhof of the University of Hohenheim, in a hilly region in Southern Germany. Particulate matter was sampled for off-line chemical analyses and physically characterized in-situ close to the animal housings as well as through simultaneous measurements upwind and downwind of the farm. Off-line analyses comprised particulate matter mass, inorganic ion content, carbon fractions, total element content, single particle analyses, besides other. Estimates on the emission term are made.

  19. StreamVOC--A Deterministic Source-Apportionment Model to Estimate Volatile Organic Compound Concentrations in Rivers and Streams

    USGS Publications Warehouse

    Asher, William E.; Bender, David A.; Zogorski, John S.; Bartholomay, Roy C.

    2006-01-01

    This report documents the construction and verification of the model, StreamVOC, that estimates (1) the time- and position-dependent concentrations of volatile organic compounds (VOCs) in rivers and streams as well as (2) the source apportionment (SA) of those concentrations. The model considers how different types of sources and loss processes can act together to yield a given observed VOC concentration. Reasons for interest in the relative and absolute contributions of different sources to contaminant concentrations include the need to apportion: (1) the origins for an observed contamination, and (2) the associated human and ecosystem risks. For VOCs, sources of interest include the atmosphere (by absorption), as well as point and nonpoint inflows of VOC-containing water. Loss processes of interest include volatilization to the atmosphere, degradation, and outflows of VOC-containing water from the stream to local ground water. This report presents the details of StreamVOC and compares model output with measured concentrations for eight VOCs found in the Aberjona River at Winchester, Massachusetts. Input data for the model were obtained during a synoptic study of the stream system conducted July 11-13, 2001, as part of the National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey. The input data included a variety of basic stream characteristics (for example, flows, temperature, and VOC concentrations). The StreamVOC concentration results agreed moderately well with the measured concentration data for several VOCs and provided compound-dependent SA estimates as a function of longitudinal distance down the river. For many VOCs, the quality of the agreement between the model-simulated and measured concentrations could be improved by simple adjustments of the model input parameters. In general, this study illustrated: (1) the considerable difficulty of quantifying correctly the locations and magnitudes of ground-water-related sources of

  20. New insight into the spatiotemporal variability and source apportionments of C1-C4 alkyl nitrates in Hong Kong

    NASA Astrophysics Data System (ADS)

    Ling, Zhenhao; Guo, Hai; Simpson, Isobel Jane; Saunders, Sandra Maria; Lam, Sean Ho Man; Lyu, Xiaopu; Blake, Donald Ray

    2016-07-01

    C1-C4 alkyl nitrates (RONO2) were measured concurrently at a mountain site, Tai Mo Shan (TMS), and an urban site, Tsuen Wan (TW), at the base of the same mountain in Hong Kong from September to November 2010. Although the levels of parent hydrocarbons were much lower at TMS (p < 0.05), similar alkyl nitrate levels were found at both sites regardless of the elevation difference, suggesting various source contributions of alkyl nitrates at the two sites. Prior to using a positive matrix factorization (PMF) model, the data at TW were divided into "meso" and "non-meso" scenarios for the investigation of source apportionments with the influence of mesoscale circulation and regional transport, respectively. Secondary formation was the prominent contributor of alkyl nitrates in the meso scenario (60 ± 2 %, 60.2 ± 1.2 pptv), followed by biomass burning and oceanic emissions, while biomass burning and secondary formation made comparable contributions to alkyl nitrates in the non-meso scenario, highlighting the strong emissions of biomass burning in the inland Pearl River delta (PRD) region. In contrast to TW, the alkyl nitrate levels measured at TMS mainly resulted from the photooxidation of the parent hydrocarbons at TW during mesoscale circulation, i.e., valley breezes, corresponding to 52-86 % of the alkyl nitrate levels at TMS. Furthermore, regional transport from the inland PRD region made significant contributions to the levels of alkyl nitrates (˜ 58-82 %) at TMS in the non-meso scenario, resulting in similar levels of alkyl nitrates observed at the two sites. The simulation of secondary formation pathways using a photochemical box model found that the reaction of alkyl peroxy radicals (RO2) with nitric oxide (NO) dominated the formation of RONO2 at both sites, and the formation of alkyl nitrates contributed negatively to O3 production, with average reduction rates of 4.1 and 4.7 pptv pptv-1 at TMS and TW, respectively.

  1. Environmental carcinogenic polycyclic aromatic hydrocarbons in soil from Himalayas, India: Implications for spatial distribution, sources apportionment and risk assessment.

    PubMed

    Devi, Ningombam Linthoingambi; Yadav, Ishwar Chandra; Shihua, Qi; Dan, Yang; Zhang, Gan; Raha, Priyankar

    2016-02-01

    The Indian Himalayan Region (IHR) is one of the important mountain ecosystems among the global mountain system which support wide variety of flora, fauna, human communities and cultural diversities. Surface soil samples (n = 69) collected from IHR were analysed for 16 priority polycyclic aromatic hydrocarbons (PAH) listed by USEPA. The ∑16PAH concentration in surface soil ranged from 15.3 to 4762 ngg(-1) (mean 458 ngg(-1)). The sum total of low molecular weight PAH (∑LMW-PAHs) (mean 74.0 ngg(-1)) were relatively lower than the high molecular weight PAH (∑HMW-PAHs) (mean 384 ngg(-1)). The concentration of eight carcinogenic PAHs (BaA, CHR, BbF, BkF, BaP, DahA, IcdP, BghiP) were detected high in mountain soil from IHR and ranged from 0.73 to 2729 ngg(-1) (mean 272 ngg(-1)). Based on spatial distribution map, high concentration of HMW- and LMW-PAHs were detected at GS1 site in Guwahati (615 and 4071 ngg(-1)), and lowest concentration of HMW-PAHs were found at IS6 in Itanagar (5.80 ngg(-1)) and LMW-PAHs at DS2 (17.3 ngg(-1)) in Dibrugarh. Total organic carbon (TOC) in mountain soil was poorly connected with ∑PAHs (r(2) = 0.072) and Car-PAHs (r(2) = 0.048), suggesting the little role of TOC in adsorption of PAHs. Isomeric ratio of PAHs showed the source of PAH contamination in IHR is mixed of petrogenic and pyrogenic origin and was affirmed by PAHs composition profile. These source apportionment results were further confirmed by principal component analysis (PCA). Eco-toxicological analysis showed the calculated TEQ for most carcinogenic PAH were 2-4 times more than the Dutch allowed limit, while TEQ of BaP was 25 times high, suggesting increasing trend of carcinogenicity of surface soil. PMID:26386774

  2. Photochemical and other sources of organic compounds in the Canadian high arctic aerosol pollution during winter-spring.

    PubMed

    Fu, Pingqing; Kawamura, Kimitaka; Barrie, Leonard A

    2009-01-15

    Total suspended particles collected at Alert in the Canadian high Arctic (February-June) were analyzed for solvent extractable organic compounds using gas chromatography-mass spectrometry to better understand the sources and source apportionment of aerosol pollution that can affect the Arctic climate. More than 100 organic species were detected in the aerosols and were grouped into different compound classes based on the functional groups. Polyacids were found to be the most abundant compound class, followed by phthalates, aromatic acids, fatty acids, fatty alcohols, sugars/sugar alcohols, and n-alkanes, while polycyclic aromatic hydrocarbons, sterols, and lignin and resin acids were minor. Concentrations of total quantified organics seemed slightly higher in darkwinter aerosols (13.2-16.6 ng m(-3), average 14.5 ng m(-3)) than those after polar sunrise (6.70-17.7 ng m(-3), average 11.8 ng m(-3)). During dark winter, fossil fuel combustion products (30-51%), secondary oxidation products, as well as higher plant emissions were found as major contributors to the Arctic aerosols. However, after polar sunrise on 5 March, secondary oxidation products (5-53%) and plasticizer-derived phthalates became the dominant compound classes, followed by fossil fuel combustion and microbial/marine sources. Biomass burning emissions were found to contribute only 0.4-6% of the total identified organics, although they maximized in dark winter. This study demonstrates that long-range atmospheric transport, changes in the solar irradiance, and ambient temperature can significantly control the chemical composition of organic aerosols in the Arctic region. PMID:19238953

  3. Source origins, modeled profiles, and apportionments of halogenated hydrocarbons in the greater Pearl River Delta region, southern China

    NASA Astrophysics Data System (ADS)

    Guo, H.; Ding, A. J.; Wang, T.; Simpson, I. J.; Blake, D. R.; Barletta, B.; Meinardi, S.; Rowland, F. S.; Saunders, S. M.; Fu, T. M.; Hung, W. T.; Li, Y. S.

    2009-06-01

    We analyze 16-month data of 13 major halocarbons measured at a southern China coastal site in the greater Pearl River Delta (PRD). A total of 188 canister air samples were collected from August 2001 to December 2002. Overall inspection indicated that CH2Cl2, C2Cl4, and C2HCl3 had similar temporal variations while CFC-11, CFC-12, and CFC-113 showed the same emission patterns during the sampling period. Diurnal variations of halocarbons presented different patterns during ozone episode days, mainly related to emission strength, atmospheric dispersion, and photochemical lifetimes. For further statistics and source appointment, Lagrangian backward particle release simulations were conducted to help understand the potential source regions of all samples and classify them into different categories, including local Hong Kong, inner PRD, continental China, and marine air masses. With the exception of HCFC-142b, the mixing ratios of all halocarbons in marine air were significantly lower than those in urban and regional air (p < 0.01), whereas no significant difference was found between urban Hong Kong and inner PRD regional air, reflecting the dominant impact of the greater PRD regional air on the halocarbon levels. The halocarbon levels in this region were significantly influenced by anthropogenic sources, causing the halocarbon mixing ratios in South China Sea air to be higher than the corresponding background levels, as measured by global surface networks and by airborne missions such as Transport and Chemical Evolution Over the Pacific. Interspecies correlation analysis suggests that CHCl3 is mainly used as a solvent in Hong Kong but mostly as a feedstock for HCFC-22 in the inner PRD. Furthermore, CH3Cl is often used as a refrigerant and emitted from biomass/biofuel burning in the inner PRD. A positive matrix factorization receptor model was applied to the classified halocarbon samples in the greater PRD for source profiles and apportionments. Seven major sources were

  4. Source apportionment of indoor, outdoor and personal PM2.5 exposure of pregnant women in Barcelona, Spain

    NASA Astrophysics Data System (ADS)

    Minguillón, M. C.; Schembari, A.; Triguero-Mas, M.; de Nazelle, A.; Dadvand, P.; Figueras, F.; Salvado, J. A.; Grimalt, J. O.; Nieuwenhuijsen, M.; Querol, X.

    2012-11-01

    Exposure to air pollution has been shown to adversely affect foetal development in the case of pregnant women. The present study aims to investigate the PM composition and sources influencing personal exposure of pregnant women in Barcelona. To this end, indoor, outdoor and personal exposure measurements were carried out for a selection of 54 pregnant women between November 2008 and November 2009. PM2.5 samples were collected during two consecutive days and then analysed for black smoke (BS), major and trace elements, and polycyclic aromatic hydrocarbons (PAHs) concentrations. Personal information such as commuting patterns and cosmetics use was also collected. PM2.5 concentrations were higher for personal samples than for indoor and outdoor environments. Indoor, outdoor and personal BS and sulphate concentrations were strongly correlated, although some specific indoor and outdoor sulphate sources may exist. Average trace elements concentrations were similar indoor, outdoor and for personal exposure, but the correlations were moderate for most of them. Most of the PAHs concentrations showed strong correlations indoor-outdoor. A source apportionment analysis of the PM composition data by means of a Positive Matrix Factorization (PMF) resulted in the identification of six sources for the outdoor and indoor environments: secondary sulphate, fueloil + sea salt (characterized by V, Ni, Na and Mg), mineral, cigarette (characterized by K, Ce, Cd, benzo(k)fluoranthene and benzo(ghi)perylene), road traffic (characterized by BS and low weight PAHs), and industrial (characterized by Pb, Sn, Cu, Mn and Fe). For personal exposure two specific sources were found: cosmetics (characterized by abundance of Ca, Li, Ti and Sr and the absence of Al) and train/subway (characterized by Fe, Mn, Cu and Ba). The contribution of the sources varied widely among women, especially for cigarette (from zero to up to 4 μg m-3), train/subway (up to more than 6 μg m-3) and cosmetics (up to more

  5. Comparative source apportionment of PM10 in Switzerland for 2008/2009 and 1998/1999 by Positive Matrix Factorisation

    NASA Astrophysics Data System (ADS)

    Gianini, M. F. D.; Fischer, A.; Gehrig, R.; Ulrich, A.; Wichser, A.; Piot, C.; Besombes, J.-L.; Hueglin, C.

    2012-07-01

    PM10 speciation data from various sites in Switzerland for two time periods (January 1998-March 1999 and August 2008-July 2009) have been analysed for major sources by receptor modelling using Positive Matrix Factorisation (PMF). For the 2008/2009 period, it was found that secondary aerosols (sulphate- and nitrate-rich secondary aerosols, SSA and NSA) are the most abundant components of PM10 at sites north of the Alps. Road traffic and wood combustion were found to be the largest sources of PM10 at these sites. Except at the urban roadside site where road traffic is dominating (40% of PM10 -- including road salt), the annual average contribution of these two sources is of similar importance (17% and 14% of PM10, respectively). At a rural site south of the Alps wood combustion and road traffic contributions to PM10 were higher (31% and 24%, respectively), and the fraction of secondary aerosols lower (29%) than at similar site types north of the Alps. Comparison of PMF analyses for the two time periods (1998/1999 and 2008/2009) revealed decreasing average contributions of road traffic and SSA to PM10 at all sites. This indicates that the measures that were implemented in Switzerland and in neighbouring countries to reduce emissions of sulphur dioxide and PM10 from road traffic were successful. On the other hand, contributions of wood combustion did not change during this ten year period, and the contribution of nitrate-rich secondary aerosols has even increased. It is shown that PMF can be a helpful tool for the assessment of long-term changes of source contributions to ambient particulate matter.

  6. Source apportionment of sediment PAHs in Lake Calumet, Chicago: application of factor analysis with nonnegative constraints.

    PubMed

    Bzdusek, Philip A; Christensen, Erik R; Li, An; Zou, Qimeng

    2004-01-01

    A factor analysis model with nonnegative constraints (FA) was used to apportion the sources of PAHs found in sediments of Lake Calumet and surrounding wetlands in southeast Chicago. Source profiles and contributions, with uncertainties, are determined with no prior knowledge of sources. The model includes scaling and backscaling of data with average PAH concentrations without sample normalization. This work is a follow-up to a study that used a chemical mass balance (CMB8.2) model to apportion sources to the same data set. Literature source profiles, modified based on gas/particle partitioning of individual PAHs, from eight PAH sources were considered for comparison. FA results for a two-source solution indicate coke oven (45%) and traffic (55%) are the primary PAH sources to Lake Calumet sediments. A six-source FA solution indicates that coke oven (47%) and traffic (45%) related sources are major PAH sources and wood burning-coal residential (2.3%) is a minor PAH source. From the six-source solution, two coke oven profiles are observed, a standard coke oven profile (33%), and a degraded or second coke oven profile (14%) low in phenanthrene and pyrene. Observed traffic related sources include gasoline engine (36%) exhaust and traffic tunnel air (9.3%). This work supports the previous study of Lake Calumet PAHs by CMB model. In addition, FA provides new insights since wood burning and secondary coke oven profiles were not recognized in the CMB model. PMID:14740723

  7. PM10 source apportionment applying PMF and chemical tracer analysis to ship-borne measurements in the Western Mediterranean

    NASA Astrophysics Data System (ADS)

    Bove, M. C.; Brotto, P.; Calzolai, G.; Cassola, F.; Cavalli, F.; Fermo, P.; Hjorth, J.; Massabò, D.; Nava, S.; Piazzalunga, A.; Schembari, C.; Prati, P.

    2016-01-01

    A PM10 sampling campaign was carried out on board the cruise ship Costa Concordia during three weeks in summer 2011. The ship route was Civitavecchia-Savona-Barcelona-Palma de Mallorca-Malta (Valletta)-Palermo-Civitavecchia. The PM10 composition was measured and utilized to identify and characterize the main PM10 sources along the ship route through receptor modelling, making use of the Positive Matrix Factorization (PMF) algorithm. A particular attention was given to the emissions related to heavy fuel oil combustion by ships, which is known to be also an important source of secondary sulphate aerosol. Five aerosol sources were resolved by the PMF analysis. The primary contribution of ship emissions to PM10 turned out to be (12 ± 4)%, while secondary ammonium sulphate contributed by (35 ± 5)%. Approximately, 60% of the total sulphate was identified as secondary aerosol while about 20% was attributed to heavy oil combustion in ship engines. The measured concentrations of methanesulphonic acid (MSA) indicated a relevant contribution to the observed sulphate loading by biogenic sulphate, formed by the atmospheric oxidation of dimethyl sulphide (DMS) emitted by marine phytoplankton.

  8. A regional assessment of marine vessel PM2.5 impacts in the U.S. Pacific Northwest using a receptor-based source apportionment method

    NASA Astrophysics Data System (ADS)

    Kotchenruther, Robert A.

    2013-04-01

    This work reports results from a receptor-based source apportionment analysis using the Positive Matrix Factorization (PMF) model on chemically speciated PM2.5 data from 36 urban and rural monitoring sites within the U.S. Pacific Northwest. The approach taken is to model each site independently, treats monitor datasets with a common data preparation protocol, and uses a common modeling protocol. Complementary data from two monitoring networks, the urban Chemical Speciation Network (CSN) and rural Interagency Monitoring of Protected Visual Environments (IMPROVE) Network, was modeled for the period of 2007-2011. 15 different factor types were found for CSN sites and 17 for IMPROVE sites, however many factors occurred at only a few locations. Only 3 factor types were common in both networks: sulfate/sulfur rich, nitrate rich, and soil. However, for coastal and near coastal monitoring sites there were three additional factors common in both networks: sea salt, aged sea salt, and residual fuel oil combustion (RFO). This work presents annual average PM2.5 mass impacts for all sites and factors found and the results for RFO are explored in greater depth. The association between RFO results and commercial marine vessel emissions is made based on similarities between factor chemical profiles and published emissions profiles, comparisons with emissions inventories, and the similarity in the spatial extent of RFO factor locations to that of the other marine aerosols identified in this study, sea salt and aged sea salt. All 14 monitoring sites with marine vessel RFO factors showed a seasonal cycle of mass impacts, with lower impacts in winter months (monthly average PM2.5 between 0.1 μg m-3 and 0.9 μg m-3 in January) and higher impacts in summer months (monthly average PM2.5 between 0.3 μg m-3 and 2.7 μg m-3 in August). These results set a baseline to measure progress in emissions reductions that are expected from implementation of the North American Emissions Control Area

  9. SOURCES OF ORGANIC AEROSOL: SEMIVOLATILE EMISSIONS AND PHOTOCHEMICAL AGING

    EPA Science Inventory

    The proposed research integrates emissions testing, smog chamber experiments, and regional chemical transport models (CTMs) to investigate the sources of organic aerosol in urban and regional environments.

  10. Bioavailability of Polycyclic Aromatic Hydrocarbons and their Potential Application in Eco-risk Assessment and Source Apportionment in Urban River Sediment

    PubMed Central

    Yang, Xunan; Yu, Liuqian; Chen, Zefang; Xu, Meiying

    2016-01-01

    Traditional risk assessment and source apportionment of sediments based on bulk polycyclic aromatic hydrocarbons (PAHs) can introduce biases due to unknown aging effects in various sediments. We used a mild solvent (hydroxypropyl-β-cyclodextrin) to extract the bioavailable fraction of PAHs (a-PAHs) from sediment samples collected in Pearl River, southern China. We investigated the potential application of this technique for ecological risk assessments and source apportionment. We found that the distribution of PAHs was associated with human activities and that the a-PAHs accounted for a wide range (4.7%–21.2%) of total-PAHs (t-PAHs), and high risk sites were associated with lower t-PAHs but higher a-PAHs. The correlation between a-PAHs and the sediment toxicity assessed using tubificid worms (r = −0.654, P = 0.021) was greater than that from t-PAH-based risk assessment (r = −0.230, P = 0.472). Moreover, the insignificant correlation between a-PAH content and mPEC-Q of low molecular weight PAHs implied the potiential bias of t-PAH-based risk assessment. The source apportionment from mild extracted fractions was consistent across different indicators and was in accordance with typical pollution sources. Our results suggested that mild extraction-based approaches reduce the potential error from aging effects because the mild extracted PAHs provide a more direct indicator of bioavailability and fresher fractions in sediments. PMID:26976450

  11. Source Resolution and Risk Apportionment of Air Emission Sources in AN Industrial Complex for Risk Reduction Considerations: AN Air Waste Management Methodology.

    NASA Astrophysics Data System (ADS)

    Mukerjee, Shaibal

    The purpose of this study was to develop an air waste management methodology for apportioning the health risks associated with air emission source categories that are identified in a given airshed. This was implemented by expanding the receptor model technique to assess the non-carcinogenic and carcinogenic inhalation risks to an exposed population for certain element pollutants determined to be coming from specific emission sources. The concept was demonstrated using air quality data from a mid-sized industrial complex located in a rural/residential area. It was demonstrated that risks from identified, major elemental emission categories can be quantified and that a total, additive risk be determined for main source categories in the airshed. Potential risk reduction measures were targeted at main risk sources without arbitrarily reducing risk for all sources in the airshed thereby making it a cost-effective approach. Dispersion modeling was utilized from previous emission inventory data so that risk estimates for these sources could be modeled at other receptor points in the airshed. The factor analytic procedure for Source Resolution in the initial receptor modeling approach was used to show whether the ambient data fitted a Maximum-Likelihood Factor Analysis or Principal Component Analysis for identifying underlying emission sources. It was also shown how Maximum -Likelihood Factor Analysis can be a stronger source resolution procedure as opposed to Principal Component Analysis since Factor Analysis is metrically invariant. Finally, the use of the ambient air data for total particulates was used to expand the Source Resolution and Risk Apportionment concepts to augment the Bubble Policy currently used in Air Quality Management.

  12. Advanced source apportionment of PM2.5 using online mass spectrometry in two major cities in China

    NASA Astrophysics Data System (ADS)

    Prevot, Andre S. H.; Elser, Miram; Huang, Rujin; Slowik, Jay; Wang, Qiyuan; Canonaco, Francesco; Bozzetti, Carlo; Cao, Junji; Baltensperger, Urs; El Haddad, Imad

    2016-04-01

    During winter 2013-2014 aerosol mass spectrometer (AMS) measurements were conducted in two major cities of China: Xi'an and Beijing. The AMS was equipped with a recently developed aerodynamic lens for direct measurements of the PM2.5 fraction for the first time in Asia (Williams et al., 2013). We could show that around 40% of the mass is lost using a conventional PM1 inlet. The statistical tool multi-linear engine 2 using constrained positive matrix factorization was used to derive the sources of organic aerosols. During the more extreme haze periods, 537 and 243 ug/m3 were recorded in Xi'an and Beijing respectively. The main results include a dominance of coal combustion in Beijing of the primary organic aerosols with a contribution of more than 90% to the cancerogenic polycyclic hydrocarbons. In Xi'an primary wood burning was a more important source. In both cities, an increase of secondary organic aerosols could be observed. The results including uncertainties will be discussed and put in perspective of previous analyses of haze in northern China including our previous analysis published in Nature (Huang et al., 2014). The study can be used as a role model for future similar analyses in Asia where the emission sources are highly complex. Huang, R.J., Cao, J.J., El Haddad, I. and Prévôt A.S.H. et al. (2014) Nature 514, 218-222. Williams, L.R., Prévôt, A.S.H., Worsnop, D.R. et al. (2013) Atmos. Meas. Tech. 6, 3271-3280.

  13. Sources of methane and nitrous oxide in California's Central Valley estimated through direct airborne flux and positive matrix factorization source apportionment of groundbased and regional tall tower measurements

    NASA Astrophysics Data System (ADS)

    Guha, Abhinav

    -San Joaquin River Delta in the Central Valley. Through analysis of these field measurements, this dissertation presents the apportionment of observed CH4 and N2O concentration enhancements into major source categories along with direct emissions estimates from airborne observations. We perform high-precision measurements of greenhouse gases using gas analyzers based on absorption spectroscopy, and other source marker volatile organic compounds (VOCs) using state of the art VOC measurement systems (e.g. proton transfer reaction mass spectrometry). We combine these measurements with a statistical source apportionment technique called positive matrix factorization (PMF) to evaluate and investigate the major local sources of CH4 and N2O during CalNex and Walnut Grove campaigns. In the CABERNET study, we combine measurements with an airborne approach to a well-established micrometeorological technique (eddy-covariance method) to derive CH4 fluxes over different source regions in the Central Valley. In the CalNex experiments, we demonstrate that dairy and livestock remains the largest source sector of non-CO2 greenhouse gases in the San Joaquin Valley contributing most of the CH4 and much of the measured N2O at Bakersfield. Agriculture is observed to provide another major source of N2O, while vehicle emissions are found to be an insignificant source of N2O, contrary to the current statewide greenhouse gas inventory which includes vehicles as a major source. Our PMF source apportionment also produces an evaporative/fugitive factor but its relative lack of CH4 contributions points to removal processes from vented emissions in the surrounding O&G industry and the overwhelming dominance of the dairy CH4 source. In the CABERNET experiments, we report enhancements of CH4 from a number of sources spread across the spatial domain of the Central Valley that improves our understanding of their distribution and relative strengths. We observe large enhancements of CH4 mixing ratios over the

  14. Source apportionment of polycyclic aromatic hydrocarbons and their derivatives in indoor air

    SciTech Connect

    Ray, B.; Mitra, S.

    1996-12-31

    The average person spends more than 80% of his time indoors, thus analysis of the sources of airborne pollutants in indoor air is an important issue. In this paper, we use factor analysis and multiple regression to identify and apportion the different sources of select indoor polycyclic aromatic hydrocarbons (PAHs), their derivatives, and nicotine in indoor air, using data gathered in eight homes in Columbus, OH during the winter of 1986/1987. These homes had different indoor PAH sources, namely, environmental tobacco smoke, gas cooking/heating, and electrical cooking stoves. We find that, of all the sources, environmental tobacco smoke appears to have the greatest impact on the total indoor PAH concentrations. In smokers` homes, more than 87% of the total PAH is due to this source. Background sources are the largest contributor to PAHs in nonsmokers` homes. Very little PAH can be attributed to gas or electric appliances in the home. 16 refs., 3 tabs.

  15. ATMOSPHERIC AEROSOL SOURCE-RECEPTOR RELATIONSHIPS: THE ROLE OF COAL-FIRED POWER PLANTS

    SciTech Connect

    Allen L. Robinson; Spyros N. Pandis; Cliff I. Davidson

    2004-04-01

    This report describes the technical progress made on the Pittsburgh Air Quality Study (PAQS) during the period of September 2003 through February 2004. Significant progress was made this project period on the analysis of ambient data, source apportionment, and deterministic modeling activities. Results highlighted in this report include chemical fractionation of the organic fraction to quantify the ratio of organic mass to organic carbon (OM/OC). The average OM/OC ratio for the 31 samples analyzed so far is 1.89, ranging between 1.62 and 2.53, which is consistent with expectations for an atmospherically processed regional aerosol. Analysis of the single particle data reveals that a on a particles in Pittsburgh consist of complex mixture of primary and secondary components. Approximately 79% of all particles measured with the instrument containing some form of carbon, with Carbonaceous Ammonium Nitrate (54.43%) being the dominant particle class. PMCAMx predictions were compared with data from more than 50 sites of the STN network located throughout the Eastern United States for the July 2001 period. OC and sulfate concentrations predicted by PMCAMx are within {+-}30% of the observed concentration at most of these sites. Spherical Aluminum Silicate particle concentrations (SAS) were used to estimate the contribution of primary coal emissions to fine particle levels at the central monitoring site. Primary emissions from coal combustion contribute on average 0.44 {+-} 0.3 {micro}g/m{sup 3} to PM{sub 2.5} at the site or 1.4 {+-} 1.3% of the total PM{sub 2.5} mass. Chemical mass balance analysis was performed to apportion the primary organic aerosol. About 70% of the primary OC emissions are from vehicular sources, with the gasoline contribution being on average three times greater than the diesel emissions in the summer.

  16. THE APPLICATION OF FACTOR ANALYSIS TO SOURCE APPORTIONMENT OF AEROSOL MASS

    EPA Science Inventory

    As part of the development of receptor models that can be employed in air quality management, the application of target transformation factor analysis (TTFA) has been under active investigation. This method has the advantage of requiring limited a priori knowledge of the number o...

  17. SOURCE APPORTIONMENT OF PRIMARY CARBONACEOUS AEROSOL USING THE COMMUNITY MULTISCALE AIR QUALITY MODEL

    EPA Science Inventory

    A substantial fraction of fine particulate matter (PM) across the United States is composed of carbon, which may be either emitted in particulate form (i.e., primary) or formed in the atmosphere through gas-to-particle conversion processes (i.e., secondary). Primary carbonaceous...

  18. Source apportionment of ambient non-methane hydrocarbons in Hong Kong: application of a principal component analysis/absolute principal component scores (PCA/APCS) receptor model.

    PubMed

    Guo, H; Wang, T; Louie, P K K

    2004-06-01

    Receptor-oriented source apportionment models are often used to identify sources of ambient air pollutants and to estimate source contributions to air pollutant concentrations. In this study, a PCA/APCS model was applied to the data on non-methane hydrocarbons (NMHCs) measured from January to December 2001 at two sampling sites: Tsuen Wan (TW) and Central & Western (CW) Toxic Air Pollutants Monitoring Stations in Hong Kong. This multivariate method enables the identification of major air pollution sources along with the quantitative apportionment of each source to pollutant species. The PCA analysis identified four major pollution sources at TW site and five major sources at CW site. The extracted pollution sources included vehicular internal engine combustion with unburned fuel emissions, use of solvent particularly paints, liquefied petroleum gas (LPG) or natural gas leakage, and industrial, commercial and domestic sources such as solvents, decoration, fuel combustion, chemical factories and power plants. The results of APCS receptor model indicated that 39% and 48% of the total NMHCs mass concentrations measured at CW and TW were originated from vehicle emissions, respectively. 32% and 36.4% of the total NMHCs were emitted from the use of solvent and 11% and 19.4% were apportioned to the LPG or natural gas leakage, respectively. 5.2% and 9% of the total NMHCs mass concentrations were attributed to other industrial, commercial and domestic sources, respectively. It was also found that vehicle emissions and LPG or natural gas leakage were the main sources of C(3)-C(5) alkanes and C(3)-C(5) alkenes while aromatics were predominantly released from paints. Comparison of source contributions to ambient NMHCs at the two sites indicated that the contribution of LPG or natural gas at CW site was almost twice that at TW site. High correlation coefficients (R(2) > 0.8) between the measured and predicted values suggested that the PCA/APCS model was applicable for estimation

  19. ISS Ambient Air Quality: Updated Inventory of Known Aerosol Sources

    NASA Technical Reports Server (NTRS)

    Meyer, Marit

    2014-01-01

    Spacecraft cabin air quality is of fundamental importance to crew health, with concerns encompassing both gaseous contaminants and particulate matter. Little opportunity exists for direct measurement of aerosol concentrations on the International Space Station (ISS), however, an aerosol source model was developed for the purpose of filtration and ventilation systems design. This model has successfully been applied, however, since the initial effort, an increase in the number of crewmembers from 3 to 6 and new processes on board the ISS necessitate an updated aerosol inventory to accurately reflect the current ambient aerosol conditions. Results from recent analyses of dust samples from ISS, combined with a literature review provide new predicted aerosol emission rates in terms of size-segregated mass and number concentration. Some new aerosol sources have been considered and added to the existing array of materials. The goal of this work is to provide updated filtration model inputs which can verify that the current ISS filtration system is adequate and filter lifetime targets are met. This inventory of aerosol sources is applicable to other spacecraft, and becomes more important as NASA considers future long term exploration missions, which will preclude the opportunity for resupply of filtration products.

  20. Local and distant source contributions to secondary organic aerosol in the Beijing urban area in summer

    NASA Astrophysics Data System (ADS)

    Lin, Jian; An, Junling; Qu, Yu; Chen, Yong; Li, Ying; Tang, Yujia; Wang, Feng; Xiang, Weiling

    2016-01-01

    Quantification of local and distant source contributions to particulate matter is a key issue to improving air quality in large urban areas, but few studies have focused on secondary organic aerosol (SOA) source contributions in a large area, especially in China. In this study, we extended the Comprehensive Air Quality Model with Extensions (CAMX) version 5.4, replacing the two-product approach by the volatility basis-set (VBS) approach, with updated SOA yields based on smog chamber studies. The modules related to the computationally efficient particulate source apportionment technology (PSAT) used in CAMX v5.4 were extended based on the volatility basis set (VBS) approach. The updated version of the CAMX model was then used to calculate the local and distant source contributions to SOA in Beijing for the first time. The results indicated that the VBS approach substantially improved hourly, daily, and monthly SOA simulations, compared with the two-product approach and the observations. In August 2007, the local source contributions to anthropogenic and biogenic SOA in Beijing were 23.8% and 16.6%, respectively; distant sources dominated for both anthropogenic and biogenic SOA in Beijing: Northern Hebei, Middle Hebei, Northeast China, Inner Mongolia, Shandong, and Tianjin (including Xianghe) contributed 5.1%-18.2% to anthropogenic SOA in Beijing; whereas, Inner Mongolia, Northern Hebei, and Northeast China contributed 12.2%, 18.6%, and 10.1%, respectively, to biogenic SOA in Beijing. Additionally, other areas outside China respectively contributed 5.3% and 10.8% to anthropogenic and biogenic SOA in Beijing: this could be related to strong summer monsoon.

  1. Source apportionment and pollution evaluation of heavy metals in water and sediments of Buriganga River, Bangladesh, using multivariate analysis and pollution evaluation indices.

    PubMed

    Bhuiyan, Mohammad Amir Hossain; Dampare, Samuel B; Islam, M A; Suzuki, Shigeyuki

    2015-01-01

    Concentrations of heavy metals in water and sediment samples of Buriganga River in the capital city Dhaka, Bangladesh, were studied to understand the level of heavy metals and their source apportionment. The results showed that the mean concentrations of heavy metals both in water and sediment samples were very high and, in most cases, exceeded the permissible limits recommended by the Bangladesh government and other international organizations. Significantly higher concentrations of Pb, Cr, Mn, Co, Ni, Cu, Zn, As, and Cd were found in sediment samples. However, average concentrations of metals both in water and sediment samples were above the effect range median. The heavy metal pollution index (HPI) and degree of contamination (Cd) yielded different results in water samples despite significant correlations between them. The heavy metal evaluation index (HEI) showed strong correlations with HPI and Cd and provided better assessment of pollution levels. The enrichment factor (EF) and geoaccumulation index (Igeo) showed the elevated value of Cr, Pb, and Cd in access of background values. The measured elements were subjected to positive matrix factorization (PMF) and examining correlations in order to explain the content, behavior, and source apportionment of metals. PMF resulted in a successful partitioning of variances into sources related to background geochemistry and contaminant influences. However, the PMF approach successfully demarcated the major sources of metals from tannery, paint, municipal sewage, textiles, and agricultural activities. PMID:25416128

  2. Source identification and apportionment of heavy metals in urban soil profiles.

    PubMed

    Luo, Xiao-San; Xue, Yan; Wang, Yan-Ling; Cang, Long; Xu, Bo; Ding, Jing

    2015-05-01

    Because heavy metals (HMs) occurring naturally in soils accumulate continuously due to human activities, identifying and apportioning their sources becomes a challenging task for pollution prevention in urban environments. Besides the enrichment factors (EFs) and principal component analysis (PCA) for source classification, the receptor model (Absolute Principal Component Scores-Multiple Linear Regression, APCS-MLR) and Pb isotopic mixing model were also developed to quantify the source contribution for typical HMs (Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn) in urban park soils of Xiamen, a representative megacity in southeast China. Furthermore, distribution patterns of their concentrations and sources in 13 soil profiles (top 20 cm) were investigated by different depths (0-5, 5-10, 10-20 cm). Currently the principal anthropogenic source for HMs in urban soil of China is atmospheric deposition from coal combustion rather than vehicle exhaust. Specifically for Pb source by isotopic model ((206)Pb/(207)Pb and (208)Pb/(207)Pb), the average contributions were natural (49%)>coal combustion (45%)≫traffic emissions (6%). Although the urban surface soils are usually more contaminated owing to recent and current human sources, leaching effects and historic vehicle emissions can also make deep soil layer contaminated by HMs. PMID:25698100

  3. Chemical characteristics and source apportionment of PM2.5 during the harvest season in eastern China's agricultural regions

    NASA Astrophysics Data System (ADS)

    Li, Jianfeng; Song, Yu; Mao, Yi; Mao, Zhichun; Wu, Yusheng; Li, Mengmeng; Huang, Xin; He, Qichao; Hu, Min

    2014-08-01

    To determine the contribution of the open burning of wheat straw residues to local PM2.5 during the harvest season of June 2013, PM2.5 was sampled in an agricultural region in eastern China. The sampling site was approximately 1 km from the nearest wheat field. Chemical compositions were analyzed, and source apportionment was undertaken using the positive matrix factorization model. The average PM2.5 concentration was 110.7 μg/m3, containing 36.4 μg/m3 organics, 7.3 μg/m3 EC, 6.0 μg/m3 potassium (K) and 4.9 μg/m3 chloride ion (Cl-). The sampling period was divided into three phases: the pre-local-burning phase (Phase 1), the local-burning phase (Phase 2) and the post-local-burning phase (Phase 3). In Phase 2, the concentrations of PM2.5 and the organics, EC, K and Cl- in PM2.5 were 163.6 μg/m3, 59.0 μg/m3, 12.2 μg/m3, 11.0 μg/m3 and 10.8 μg/m3, respectively, which were all remarkably higher than in both Phase 1 and Phase 3. Eight sources of PM2.5 were determined, including two types of wheat residue burning sources, which showed a significant difference in Cl- content. The atmospheric relative humidity (RH) and the aging process of PM2.5 might be the causes: only fresh particulate emissions from wheat residue burning could feature high-concentration Cl- under high RH conditions. In Phase 2, wheat residue burning contributed 51.3% of PM2.5, 75.8% of OC, 74.5% of EC, 90.1% of K and 104.1% of Cl-. These percentages were lower in Phases 1 and 3 than in Phase 2. Wheat residue burning caused such severe air pollution that it's necessary to prohibit the open burning of crop residues in order to protect public health and the environment.

  4. Source apportionment of PM10 and PM2.5 near a large mining zone in Northern Chile

    NASA Astrophysics Data System (ADS)

    Jorquera, H.

    2008-12-01

    Chile's economic growth is mainly driven by intensive mining activities; currently Chile produces ~ 40% of copper worldwide. Most of those activities are located in northern Chile, in a desert region where strong regional winds contribute with soil erosion as well. The city of Calama (22.4°S, 68.9°W) is about 17 km south of Chuquicamata, one of the largest open pit copper mines in the world, both located on the west edge of the Andes; Calama is at 2,400 m asl and it is 215 km east of the Pacific Ocean. The mining complex releases ~ 21 kton/y of PM10 and ~ 78 kton/y of SO2 from a copper smelter. The levels of ambient PM10 have steadily increased at Calama in the last 5 years, so there is concern about the impacts from copper industry in the city´s inhabitants, most of who work in mining or related economic activities. A campaign was conducted at Calama between October and December 2007, sampling ambient PM10 and PM2.5 at several sites across the city. Filters were analyzed at the Desert Research Institute, Reno, NV for elemental composition by XRF and for elemental and organic carbon using thermal analysis. The application of positive matrix factorization (PMF) model identified four sources contributing to ambient PM2.5: secondary sulfates (49%), traffic emissions (37%), dust street (9%) and copper smelter emissions (5%). In the coarse fraction, four sources were identified: dust street (45%), wind erosion (34%), mineral processing (14%) and copper smelter emissions (7%). No natural background was found for PM2.5. For ambient PM10 the source apportionment obtained is: mining activities (33%), street dust (34%), wind erosion (22%) and traffic emissions (12%). With a current PM10 annual average of 58 μg/m3 and further mining activities projected in the area, there is a big challenge to improve air quality in the populated area close to the mining operations.

  5. Source apportionment of PM10 mass and particulate carbon in the Kathmandu Valley, Nepal

    NASA Astrophysics Data System (ADS)

    Kim, Bong Mann; Park, Jin-Soo; Kim, Sang-Woo; Kim, Hyunjae; Jeon, Haeun; Cho, Chaeyoon; Kim, Ji-Hyoung; Hong, Seungkyu; Rupakheti, Maheswar; Panday, Arnico K.; Park, Rokjin J.; Hong, Jihyung; Yoon, Soon-Chang

    2015-12-01

    The Kathmandu Valley in Nepal is a bowl-shaped urban basin in the Himalayan foothills with a serious problem of fine particulate air pollution that impacts local health and impairs visibility. Particulate carbon concentrations have reached severe levels that threaten the health of 3.5 million local residents. Moreover, snow and ice on the Himalayan mountains are melting as a result of additional warming due to particulate carbon, especially high black carbon concentrations. To date, the sources of the Valley's particulate carbon and the impacts of different sources on particulate carbon concentrations are not well understood. Thus, before an effective control strategy can be developed, these particulate carbon sources must be identified and quantified. Our study has found that the four primary sources of particulate carbon in the Kathmandu Valley during winter are brick kilns, motor vehicles, fugitive soil dust, and biomass/garbage burning. Their source contributions are quantified using a recently developed new multivariate receptor model SMP. In contrast to other highly polluted areas such as China, secondary contribution is almost negligible in Kathmandu Valley. Brick kilns (40%), motor vehicles (37%) and biomass/garbage burning (22%) have been identified as the major sources of elemental carbon (black carbon) in the Kathmandu Valley during winter, while motor vehicles (47%), biomass/garbage burning (32%), and soil dust (13%) have been identified as the most important sources of organic carbon. Our research indicates that controlling emissions from motor vehicles, brick kilns, biomass/garbage burning, and soil dust is essential for the mitigation of the particulate carbon that threatens public health, impairs visibility, and influences climate warming within and downwind from the Kathmandu Valley. In addition, this paper suggests several useful particulate carbon mitigation methods that can be applied to Kathmandu Valley and other areas in South Asia with

  6. PM10 source apportionment in a Swiss Alpine valley impacted by highway traffic.

    PubMed

    Ducret-Stich, Regina E; Tsai, Ming-Yi; Thimmaiah, Devraj; Künzli, Nino; Hopke, Philip K; Phuleria, Harish C

    2013-09-01

    Although trans-Alpine highway traffic exhaust is one of the major sources of air pollution along the highway valleys of the Alpine regions, little is known about its contribution to residential exposure and impact on respiratory health. In this paper, source-specific contributions to particulate matter with an aerodynamic diameter < 10 μm (PM10) and their spatio-temporal distribution were determined for later use in a pediatric asthma panel study in an Alpine village. PM10 sources were identified by positive matrix factorization using chemical trace elements, elemental, and organic carbon from daily PM10 filters collected between November 2007 and June 2009 at seven locations within the village. Of the nine sources identified, four were directly road traffic-related: traffic exhaust, road dust, tire and brake wear, and road salt contributing 16 %, 8 %, 1 %, and 2 % to annual PM10 concentrations, respectively. They showed a clear dependence with distance to highway. Additional contributions were identified from secondary particles (27 %), biomass burning (18 %), railway (11 %), and mineral dust including a local construction site (13 %). Comparing these source contributions with known source-specific biomarkers (e.g., levoglucosan, nitro-polycyclic aromatic hydrocarbons) showed high agreement with biomass burning, moderate with secondary particles (in winter), and lowest agreement with traffic exhaust. PMID:23608980

  7. Source apportionment of airborne nanoparticles in a Middle Eastern city using positive matrix factorization.

    PubMed

    Al-Dabbous, Abdullah N; Kumar, Prashant

    2015-04-01

    Airborne nanoparticles have been studied worldwide, but little is known about their sources in the Middle East region, where hot, arid and dusty climatic conditions generally prevail. For the first time in Kuwait, we carried out size-resolved measurements of particle number distributions (PNDs) and concentrations (PNCs) in the 5-1000 nm size range. Measurements were made continuously for 31 days during the summer months of May and June 2013 using a fast-response differential mobility spectrometer (Cambustion DMS500) at a sampling rate of 10 Hz. Sources and their contributions were identified using the positive matrix factorization (PMF) approach that was applied to the PND data. Simultaneous measurements of gaseous pollutants (i.e., O3, NO, NOx, SO2 and CO), PM10, wind speed and direction were also carried out to aid the interpretation of the PMF results through the conditional probability function plots and Pearson product-moment correlations. Six major sources of PNCs were identified, contributing ∼46% (fresh traffic emissions), 27% (aged traffic emissions), 9% (industrial emissions), 9% (regional background), 6% (miscellaneous sources) and 3% (Arabian dust transport) of the total PNCs. The sources of nanoparticles and their PND profiles identified could serve as reference data to design more detailed field studies in the future and treat these sources in dispersion modelling and health impact assessment studies. PMID:25749465

  8. Characterization and source apportionment of particle number concentration at a semi-urban tropical environment.

    PubMed

    Khan, Md Firoz; Latif, Mohd Talib; Amil, Norhaniza; Juneng, Liew; Mohamad, Noorlin; Nadzir, Mohd Shahrul Mohd; Hoque, Hossain Mohammed Syedul

    2015-09-01

    Principal component analysis (PCA) and correlation have been used to study the variability of particle mass and particle number concentrations (PNC) in a tropical semi-urban environment. PNC and mass concentration (diameter in the range of 0.25->32.0 μm) have been measured from 1 February to 26 February 2013 using an in situ Grimm aerosol sampler. We found that the 24-h average total suspended particulates (TSP), particulate matter ≤10 μm (PM10), particulate matter ≤2.5 μm (PM2.5) and particulate matter ≤1 μm (PM1) were 14.37 ± 4.43, 14.11 ± 4.39, 12.53 ± 4.13 and 10.53 ± 3.98 μg m(-3), respectively. PNC in the accumulation mode (<500 nm) was the most abundant (at about 99 %). Five principal components (PCs) resulted from the PCA analysis where PC1 (43.8 % variance) predominates with PNC in the fine and sub-microme tre range. PC2, PC3, PC4 and PC5 explain 16.5, 12.4, 6.0 and 5.6 % of the variance to addr