32 research outputs found

    Comparative study of the atmospheric chemical composition of three South American cities

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    PM10 samples were collected in 2008 at three sites in South America in the framework of an international project (South American Emissions Megacities, and Climate; SAEMC). The concentration of metals, metalloids, ion and organic compounds of most PM10 samples collected at three sites (Buenos Aires (BAI), Bogotá (BOG) and São Paulo (SPA)) is below the air quality standard of the respective countries. At the sites n-alkanes and carbon preference index distribution indicated the influence of petroleum residues derived from vehicular emissions. Most PAH detected are attributed to light-duty gasoline vehicles and to stationary sources. At all sites benzo[a]pyrene equivalent values mean a significant cancer risk. Sulfate, nitrate, ammonium, calcium and sodium are the most abundant water-soluble ions at the three sites. Ammonium sulfate is likely the form presented for these species formed by photochemical reactions of precursors emitted mainly by vehicles. At BAI and SPA, formate/acetate ratios indicated the contribution of photochemical reactions; on the contrary, at BOG site, acetate is predominant, indicating strong contribution of vehicular emissions. São Paulo samples showed the highest concentrations of elements among all the sites. None of the toxic or potentially toxic elements exceed the guideline values of the World Health Organization. At BAI site earth crust seems to be the major source of Fe and Mn; at SPA, anthropogenic source is responsible for Pb and Zn presences. Traffic related element is well correlated at the three sites.Fil: Vasconcellos, Pérola C.. Universidade de Sao Paulo; BrasilFil: Souza, Davi Z.. Instituto Nacional de Pesquisas Nucleares; BrasilFil: Ávila, Simone G.. Universidade de Sao Paulo; BrasilFil: Araújo, Maria P.. Universidade de Sao Paulo; BrasilFil: Naoto, Edson. Universidade de Sao Paulo; BrasilFil: Nascimento, Kátia H.. Universidade de Sao Paulo; BrasilFil: Cavalcante, Fernando S.. Universidade de Sao Paulo; BrasilFil: Dos Santos, Marina. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Smichowski, Patricia Nora. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Behrentz, Eduardo. Universidad de los Andes; Colombi

    Quantification and source identification of atmospheric particulate polycyclic aromatic hydrocarbons and their dry deposition fluxes at three sites in Salvador Basin, Brazil, impacted by mobile and stationary sources

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    The present work has aimed to determine the 16 US EPA priority PAH atmospheric particulate matter levels present in three sites around Salvador, Bahia: (i) Lapa bus station, strongly impacted by heavy-duty diesel vehicles; (ii) Aratu harbor, impacted by an intense movement of goods, and (iii) Bananeira village on Maré Island, a non vehicle-influenced site with activities such as handcraft work and fisheries. Results indicated that BbF (0.130-6.85 ng m-3) is the PAH with highest concentration in samples from Aratu harbor and Bananeira and CRY (0.075-6.85 ng m-3) presented higher concentrations at Lapa station. PAH sources from studied sites were mainly of anthropogenic origin such as gasoline-fueled light-duty vehicles and diesel-fueled heavy-duty vehicles, discharges in the port, diesel burning from ships, dust ressuspension, indoor soot from cooking, and coal and wood combustion for energy production.O presente trabalho apresenta o estudo sobre 16 HPAs prioritários em material particulado atmosférico de três sítios próximos a Salvador-BA: (i) Estação da Lapa, estação de ônibus da Região Metropolitana de Salvador; (ii) Porto de Aratu, impactado por intenso movimento de matérias-primas e (iii) Bananeira, localizado na Ilha de Maré, vilarejo que tem como principais atividades a pesca e artesanato. Resultados mostraram que o BbF (0,130-6,85 ng m-3) foi o HPA com as concentrações mais elevadas em Aratu e Bananeira e CRY (0,075-6,85 ng m-3) apresentou nível mais elevado na Lapa. As fontes de HPAs nos sítios estudados foram principalmente de origem antrópica, tais como veículos de pequeno e grande portes, carregamentos do porto, ressuspensão de partículas do solo, queima de diesel das embarcações e a queima de carvão e madeira para produção de energia.CNPqCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)FINEPFAPESBPRONEXRECOMBIONordeste GenerationANEELFAPES

    Structural signatures of water-soluble organic aerosols in contrasting environments in South America and Western Europe

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    This study describes and compares the key structural units present in water-soluble organic carbon (WSOC) fraction of atmospheric aerosols collected in different South American (Colombia – Medellín and Bogotá, Peru – Lima, Argentina – Buenos Aires, and Brazil – Rio de Janeiro, São Paulo, and Porto Velho, during moderate (MBB) and intense (IBB) biomass burning) and Western European (Portugal – Aveiro and Lisbon) locations. Proton nuclear magnetic resonance (1H NMR) spectroscopy was employed to assess the relative distribution of non-exchangeable proton functional groups in aerosol WSOC of diverse origin, for the first time to the authors’ knowledge in South America. The relative contribution of the proton functional groups was in the order H-C > H–C–C= > H-C-O > Ar-H, except in Porto Velho during MBB, Medellín, Bogotá, and Buenos Aires, for which the relative contribution of H-C-O was higher than that of H-C-C=. The 1H NMR source attribution confirmed differences in aging processes or regional sources between the two geographic regions, allowing the differentiation between urban combustion-related aerosol and biological particles. The aerosol WSOC in Aveiro, Lisbon, and Rio de Janeiro during summer are more oxidized than those from the remaining locations, indicating the predominance of secondary organic aerosols. Fresh emissions, namely of smoke particles, becomes important during winter in Aveiro and São Paulo, and in Porto Velho during IBB. The biosphere is an important source altering the chemical composition of aerosol WSOC in South America locations. The source attribution in Medellín, Bogotá, Buenos Aires, and Lima confirmed the mixed contributions of biological material, secondary formation, as well as urban and biomass burning emissions. Overall, the information and knowledge acquired in this study provide important diagnostic tools for future studies aiming at understanding the water-soluble organic aerosol problem, their sources and impact at a wider geographic scale.Fil: Duarte, Regina M.B.O.. Universidade de Aveiro; PortugalFil: Matos, João T.V.. Universidade de Aveiro; PortugalFil: Paula, Andreia S.. Universidade de Aveiro; PortugalFil: Lopes, Sónia P.. Universidade de Aveiro; PortugalFil: Pereira, Guilherme. Universidade de Sao Paulo; BrasilFil: Vasconcellos, Pérola. Universidade de Sao Paulo; BrasilFil: Gioda, Adriana. Universidade Federal do Rio de Janeiro; BrasilFil: Carreira, Renato. Universidade Federal do Rio de Janeiro; BrasilFil: Silva, Artur M.S.. Universidade de Aveiro; PortugalFil: Duarte, Armando C.. Universidade de Aveiro; PortugalFil: Smichowski, Patricia Nora. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rojas, Nestor. Universidad Nacional de Colombia; ColombiaFil: Sanchez Ccoyllo, Odon. No especifíca

    Study on polycyclic aromatic hydrocarbons and their derivatives, and saturated aliphatic hydrocarbons charactization determined on atmospheric particulate matter collected in urban, suburban and forest areas

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    Entre os componentes orgânicos do material particulado atmosférico, os hidrocarbonetos policíclicos aromáticos tem importância pois além de responder positivamente a testes de mutagenicidade como os que utilizam a Salmonella typhimurium, fornecem informações sôbre a origem e a reatividade atmosférica. Em particular os isômeros do nitropireno e nitrofluoranteno são indicadores da poluição veicular (1-nitropireno é emitido diretamente por motores a diesel) ou relacionam-se a reatividade fotoquímica (2-nitrofluoranteno e 2-nitropireno são formados na fase gasosa pela reação dos HPAs precursores com NO2 e radicais OH e NO3). Este estudo teve o objetivo de identificar e quantificar os nitro-HPAs visando a avaliação da contribuição antropogênica e fotoquímica nos estudos dos processos responsáveis pela presença destes nitroarenos na atmosfera em sítios com diferentes características, comparando resultados obtidos nos centros urbanos (emissões diretas) e na floresta Amazônica (possível emissão durante a queima da biomassa). Paralelamente foi avaliada a ocorrência dos HPAs e dos hidrocarbonetos alifáticos saturados. Estes forneceram informações sôbre as principais fontes de emissão dos particulados nos vários sítios, a contribuição relativa das emissões naturais e antropogênicas e o tempo de residência das partículas. Na primeira fase do estudo foi desenvolvida uma metodologia para a separação dos nitro-HPAs, dos hidrocarbonetos alifáticos, HPAs e HPAs oxigenados que são particularmente abundantes no material particulado emitido pelos veículos e durante as queimadas. Esta metodologia foi testada e aperfeiçoada na Itália sôbre amostras coletadas em 3 sítios diferentes por amostradores de grande volume. Após a extração em Soxhlet, foi desenvolvido um método de extração líquida mais simples e rápida que as recentemente publicadas metodologias de separação, baseadas em colunas de alumina básica. A boa separação das classes de compostos mostrou que a metodologia desenvolvida foi adequada para determinação posterior dos HPAs, nitro-HPAs e oxi-HPAs em amostras de composição complexa como aquelas de origem natural, antropogênica e fotoquímica, típicas da Amazônia e São Paulo, que foram posteriormente analisadas.A detailed knowledge of the organic components of the atmospheric suspended particulate matter is extremely useful for assessing the photochemical reactivity of the atmosphere, long-range transport of polluted air masses and the relative contribution of natural and anthropogenic sources to the total amount of organic matter that can be introduced into man\' s body. Among the organic species is very important the knowledge of the levels reached by nitrated polycyclic aromatic hydrocarbons (nitro-PAH) in general, and particularly nitrofluoranthene (NF a) and nitropyrene (NPy) isomers since these compounds not only provides information on the extent to which anthropogenic sources can contribute to suspended particulate matter but it is also useful for evaluating the photochemical processes occurring in the atmosphere. The possibility to use nitrofluoranthene and nitropyrene as indicators of biogenic emission and photochemical smog pollution associated with the observation that one of them (l-nitropyrene) is directly emitted by vehicular sources whereas the others (2-NFa and 2-NPy) are formed by gas-phase reactions of their parent PAH with OH and N03 radicals in the presence of N02. Another important reason for monitoring nitro-PAH is that they positively respond to mutagenicity tests performed with Salmonella typhimurium Strain TA 98 carried out without activation. This work had the aim of identify and quantify the nitro-PAH to evaluate the anthropogenic and photochemical contribution and study the main processes risponsible for the presence of these nitroarenes in the atmosphere in sites of differents characteristics, comparing the results of urban sites (direct emissions) to the forest sites. It is also important to know the particulate matter composition with respect to n-alkanes and PAH associated with the particulate matter because they provide indication on the main sources contributing to airbome particles, the reI ative contribution of natural vs. man-made emission and the aging of the particles. In the first part of this work a methodology to separate the nitro-PAH from the n-alkanes, PAH and oxy-PAH which are particularly abundant in the particulate matter emitted by the vehicles and during the biomass burning was developed. This new methodology has been tested and improved in Italy on samples from three different sites collected on Hi-vol filters which were submited to Soxhlet extraction and then purified by a new liquid-liquid extraction method which is simpler and faster than the recently published basic alumina based purification procedure. The results indicate the new methodology was suitable to determine the PAH, nitro-PAH and oxy-PAH in samples of complex composition as those from Amazon Basin and São Paulo City which were analysed later

    Study on polycyclic aromatic hydrocarbons and their derivatives, and saturated aliphatic hydrocarbons charactization determined on atmospheric particulate matter collected in urban, suburban and forest areas

    No full text
    Entre os componentes orgânicos do material particulado atmosférico, os hidrocarbonetos policíclicos aromáticos tem importância pois além de responder positivamente a testes de mutagenicidade como os que utilizam a Salmonella typhimurium, fornecem informações sôbre a origem e a reatividade atmosférica. Em particular os isômeros do nitropireno e nitrofluoranteno são indicadores da poluição veicular (1-nitropireno é emitido diretamente por motores a diesel) ou relacionam-se a reatividade fotoquímica (2-nitrofluoranteno e 2-nitropireno são formados na fase gasosa pela reação dos HPAs precursores com NO2 e radicais OH e NO3). Este estudo teve o objetivo de identificar e quantificar os nitro-HPAs visando a avaliação da contribuição antropogênica e fotoquímica nos estudos dos processos responsáveis pela presença destes nitroarenos na atmosfera em sítios com diferentes características, comparando resultados obtidos nos centros urbanos (emissões diretas) e na floresta Amazônica (possível emissão durante a queima da biomassa). Paralelamente foi avaliada a ocorrência dos HPAs e dos hidrocarbonetos alifáticos saturados. Estes forneceram informações sôbre as principais fontes de emissão dos particulados nos vários sítios, a contribuição relativa das emissões naturais e antropogênicas e o tempo de residência das partículas. Na primeira fase do estudo foi desenvolvida uma metodologia para a separação dos nitro-HPAs, dos hidrocarbonetos alifáticos, HPAs e HPAs oxigenados que são particularmente abundantes no material particulado emitido pelos veículos e durante as queimadas. Esta metodologia foi testada e aperfeiçoada na Itália sôbre amostras coletadas em 3 sítios diferentes por amostradores de grande volume. Após a extração em Soxhlet, foi desenvolvido um método de extração líquida mais simples e rápida que as recentemente publicadas metodologias de separação, baseadas em colunas de alumina básica. A boa separação das classes de compostos mostrou que a metodologia desenvolvida foi adequada para determinação posterior dos HPAs, nitro-HPAs e oxi-HPAs em amostras de composição complexa como aquelas de origem natural, antropogênica e fotoquímica, típicas da Amazônia e São Paulo, que foram posteriormente analisadas.A detailed knowledge of the organic components of the atmospheric suspended particulate matter is extremely useful for assessing the photochemical reactivity of the atmosphere, long-range transport of polluted air masses and the relative contribution of natural and anthropogenic sources to the total amount of organic matter that can be introduced into man\' s body. Among the organic species is very important the knowledge of the levels reached by nitrated polycyclic aromatic hydrocarbons (nitro-PAH) in general, and particularly nitrofluoranthene (NF a) and nitropyrene (NPy) isomers since these compounds not only provides information on the extent to which anthropogenic sources can contribute to suspended particulate matter but it is also useful for evaluating the photochemical processes occurring in the atmosphere. The possibility to use nitrofluoranthene and nitropyrene as indicators of biogenic emission and photochemical smog pollution associated with the observation that one of them (l-nitropyrene) is directly emitted by vehicular sources whereas the others (2-NFa and 2-NPy) are formed by gas-phase reactions of their parent PAH with OH and N03 radicals in the presence of N02. Another important reason for monitoring nitro-PAH is that they positively respond to mutagenicity tests performed with Salmonella typhimurium Strain TA 98 carried out without activation. This work had the aim of identify and quantify the nitro-PAH to evaluate the anthropogenic and photochemical contribution and study the main processes risponsible for the presence of these nitroarenes in the atmosphere in sites of differents characteristics, comparing the results of urban sites (direct emissions) to the forest sites. It is also important to know the particulate matter composition with respect to n-alkanes and PAH associated with the particulate matter because they provide indication on the main sources contributing to airbome particles, the reI ative contribution of natural vs. man-made emission and the aging of the particles. In the first part of this work a methodology to separate the nitro-PAH from the n-alkanes, PAH and oxy-PAH which are particularly abundant in the particulate matter emitted by the vehicles and during the biomass burning was developed. This new methodology has been tested and improved in Italy on samples from three different sites collected on Hi-vol filters which were submited to Soxhlet extraction and then purified by a new liquid-liquid extraction method which is simpler and faster than the recently published basic alumina based purification procedure. The results indicate the new methodology was suitable to determine the PAH, nitro-PAH and oxy-PAH in samples of complex composition as those from Amazon Basin and São Paulo City which were analysed later

    Chemical markers of biomass burning: Determination of levoglucosan, and potassium in size-classified atmospheric aerosols collected in Buenos Aires, Argentina by different analytical techniques

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    A study concerning the identification and quantification of key chemical markers of biomass burning namely, levoglucosan and potassium in size-fractionated airborne particulate matter was conducted. To perform a complete characterization of PM2.5 and PM10 samples collected in Buenos Aires, Argentina black carbon, metals and metalloids were also determined. Due to the particularly complex chemical composition of atmospheric aerosols several analytical techniques were employed. Levoglucosan was extracted from filters and determined by gas chromatography–mass spectrometry (GC–MS). It was detected in a wide range of concentrations, from 2.0 ng m−3 to 4.90 μg m−3 (PM2.5) and 6.0 ng m−3 to 1.86 μg m−3 (PM10). Equivalent black carbon concentrations were determined by reflectromety and varied between 3.3 and 8.9 μg m−3. Other tracer of biomass burning such as Potassium was determined by flame atomic absorption spectrometry (FAAS). Potassium was mainly detected in the coarse fraction varying from <0.56 to 3.51 μg m−3. In addition, 17 minor, major and trace elements (Al, As, Ba, Cr, Cu, Fe, Hg, Mg, Mn, Ni, Pb, Sb, Se, Sn, Ti, V and Zn) were determined by plasma-based techniques namely, inductively coupled plasma optical emission spectrometry (ICP OES) and inductively coupled plasma-mass spectrometry (ICP-MS). Mean concentrations (in ng m−3) of metals and metalloids varied from 1.57 (Hg) to 1688 (Al) for PM2.5 and 1.5 (Al) to 1502 (Hg) for PM10.Fil: Achad, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Caumo, Sofía. Universidade de Sao Paulo; BrasilFil: de Castro Vasconcellos, Pérola. Universidade de Sao Paulo; BrasilFil: Bajano, Héctor. Comisión Nacional de Energía Atómica; ArgentinaFil: Gómez, Darío. Comisión Nacional de Energía Atómica; ArgentinaFil: Smichowski, Patricia Nora. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; Argentin
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