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Contaminação ambiental por microplásticos em Fernando de Noronha, Abrolhos e TrindadeSUL, Juliana Assunção Ivar do 16 May 2014 (has links)
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Previous issue date: 2014-05-16 / Recentemente, a comunidade científica especializada vem concentrando seus esforços na
identificação, caracterização e quantificação dos microplásticos, definidos pela literatura como
partículas plásticas menores que 5 milímetros. Microplásticos então presentes na superfície dos
oceanos, em praias arenosas e ambientes lamosos, desde o Equador até os Pólos, em praias urbanas
e regiões remotas do globo, e ainda depositados em sedimentos profundos (>2.000m).
Experimentos de laboratório indicam que estas partículas plásticas podem ser ingeridas por
organismos de todos os níveis da teia trófica marinha. Poluentes orgânicos, como DDTs e PCBs, e
inorgânicos presentes na água do mar podem estar adsorvidos a estes plásticos, transportando
contaminantes químicos para diversas regiões do globo, ou sendo liberados quando no trato
gastrointestinal de vertebrados e invertebrados se ingeridos, podendo ainda ser transportados ao
longo da teia trófica marinha. Há mais de 10 anos relata-se que no Oceano Pacífico Norte
microplásticos estão presentes principalmente no centro do giro subtropical, aparentemente
influenciados por variáveis oceanográficas. Para o Oceano Atlântico tropical, evidências sobre a
presença de microplásticos existiam apenas para as praias arenosas do Arquipélago de Fernando de
Noronha (3°S, 32°W), e para as águas adjacentes ao Arquipélago de São Pedro e São Paulo. Para
preencher esta lacuna, microplásticos foram o foco da amostragem em três importantes ambientes
insulares no oeste do Oceano Atlântico tropical: Arquipélago de Fernando de Noronha,
Arquipélago de Abrolhos (17°S, 38°W) e a Ilha da Trindade (20°S, 29°W) em 4 expedições
científicas realizadas entre dezembro de 2011 e março de 2013. Plásticos flutuantes foram
amostrados através de arrastos planctônicos (neuston) nas áreas marinhas adjacentes a estes
ambientes. Um total de 160 arrastos foi realizado. Em Trindade, mais de 90% dos arrastos estavam
contaminados por microplásticos, identificados como fragmentos duros, fragmentos moles, paint
chips, linhas e fibras. Em Noronha e Abrolhos aproximadamente metade dos arrastos estava
contaminada. Fragmentos plásticos duros foram os tipos de itens mais amostrados assim como em
outros estudos de microplásticos em amostras de plâncton. Entre os fragmentos, >75% tinham 5mm
ou menos. A contaminação média foi de 0,03 partículas por m3, inferior às quantidades previamente
conhecidas no Oceano Pacífico. As amostras de microplásticos depositados na superfície do
sedimento foram coletadas nas praias arenosas em cada uma das ilhas através de quadrantes. As
amostras coletadas também foram analisadas quanto a granulometria predominante, já que estas
informações ainda eram inexistentes para as ilhas estudadas. Em Abrolhos nenhuma partícula
plástica foi amostrada. Fragmentos plásticos duros e esférulas plásticas foram identificados somente
em Fernando de Noronha e Trindade, sendo que o lado mais exposto à ação de ventos e corrente
superficias predominantes estava mais contaminado, quando comparado ao lado relativamente mais
protegido nas ilhas estudadas. Estes resultados são os primeiros indícios da contaminação do oeste
do Oceano Atlântico tropical em relação à contaminação por microplásticos. A presença destes
microplásticos alerta para a vulnerabilidade destas ilhas e sua biota em relação á contaminação por
plásticos. / Recently, the scientific community is focussed on the identification, characterization e
quantification of microplastics, defined in the literature as those plastic particles with less than 5
millimetres. Microplastics are widespread on the ocean’s surface, on sand beaches and mud
sediments, from the equator to the poles, on urban beaches and remote regions in the globe, and
even deposited on deep sediments (>2,000m). Laboratory experiments indicate that organisms from
every level of the marine food web potentially ingest microplastic particles. Organic, such as DDTs
and PCBs, and inorganic pollutants available in seawater may adsorbed onto microplastics,
transporting chemical contaminants to diverse regions in the globe, or being released in the
gastrointestinal tract of vertebrates and invertebrates if ingested, when they are even transported
along the marine food web. For more than 10 years, there were reports on the occurrence of
microplastics in the North Pacific Ocean, mainly in the centre of the subtropical gyre, probably
influenced by oceanographic variables. To the tropical Atlantic Ocean, however, evidences on the
presence of microplastics were available only to sandy beaches in the Fernando de Noronha
Archipelago (3°S, 32°W), and to waters around the São Pedro e São Paulo Archipelago. To fulfil
this gap, microplastics were studied in three important insular environments in the western Atlantic
Ocean: the Fernando de Noronha Archipelago, the Abrolhos Archipelago (17°S, 38°W) and the
Trindade island (20°S, 29°W), during four scientific expeditions between December 2011 and
March 2103. Floating plastics were collected by plankton tows (neuston) on the sea surface in the
adjacent region to these environments. A total of 160 tows were conducted. In Trindade Island,
more than 90% of the tows were contaminated with microplastics, identified as hard plastic
fragments, soft fragments, paint chips, lines and fibres. In Fernando de Noronha and Abrolhos,
approximately half of the tows were contaminated. Hard plastic fragments were the majority of the
sampled items, as well as reported in other studies with plankton samples. Among plastic
fragments, >75% had 5mm or less. The mean contamination pattern was 0.03 particles/m3, less than
previously reported on the Pacific Ocean. Microplastics sampled on sediments were collected on
sandy beaches in each island by quadrants dispoded in the strandline. Samples were also analysed
in the relation to the main grain size of sediments because these information was still non-existent
to the studied islands. In Abrolhos, no plastic particle was sampled. Hard plastic fragments and
plastic pellets were identified in Fernando de Noronha and Trindade, where the windward side of
the islans were significantly more contaminated when compared to the leeward side. These results
are the first results indicating the occurrence of microplastic debris particles in the Western tropical
Atlantic Ocean. The occurrence of microplastics highlights the vulnerability of these islands and
their biota in relation to microplastic pollution.
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[en] EVALUATION OF ENVIRONMENTAL FATE AND COMPARISON OF PESTICIDES WITH THE MULTIMEDIA MODEL CAPA / [pt] ANÁLISE DE DESTINO AMBIENTAL E COMPARAÇÃO DE PESTICIDAS ATRAVÉS DO MODELO DE MULTIMEIOS CAPARAMON DE ATTAYDE BARROS DE SOUZA 16 March 2004 (has links)
[pt] Este estudo propõe a apresentação de um modelo de
multimeios, denominado CAPA, capaz de analisar e comparar
um elenco de 39 pesticidas num ambiente pré-determinado sob
regime estacionário. O CAPA (Calculadora para Avaliação de
Pesticidas no Ambiente) foi desenvolvido baseado no modelo
ESTAC FATE (desenvolvido pelo Canadian Environmental
Modelling Centre,Trent University, Canadá ). O modelo
funciona no Excel, é programado em Visual Basic, usa a
fugacidade como critério de equilíbrio e avalia os
pesticidas em três diferentes níveis: Nível 1 (equilíbrio),
Nível 2 (equilíbrio com entradas e saídas advectivas e
reativas) e Nível 3( sem equilíbrio com entradas
e saídas advectivas e reativas e transporte difusivo entre
meios). Cada pesticida é comparado com os demais em função
dos fatores de bioacumulação (FBA),Persistência (P),
Toxicidade (T) e Transporte de Longo Alcance (TLA). / [en] This study proposes the presentation of a multimedia model,
named CAPA, which is able to evaluate and compare a
collection of 39 pesticides in a predetermined environment
under steady state. The CAPA (Calculadora para Avaliação de
Pesticidas no Ambiente) was based in the ESTAC FATE model
(originally developed by the Canadian Environmental
Modelling Centre, Trent University, Canada). The model
works in Excel, is programmed in Visual Basic, assumes
fugacity as the equilibrium criterion and evaluates the
pesticides in three different levels: Level 1
(equilibrium), Level 2 (equilibrium with advective
and reative input and output) and Level 3 (no equilibrium
with advective and reative input and output and diffusive
transport between media). Each pesticide is also compared
with the others as a function of the bioaccumulation fator,
persistence, toxicity and long range transport.
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Analysis of the physical and chemical properties of atmospheric aerosol at the Puy de Dôme station / Analyse des propriétés physiques et chimiques de l’aérosol atmosphérique à la station du Puy de DômeFarah, Antoine 19 December 2018 (has links)
Les particules d'aérosol sont importantes en raison de leurs impacts directs et indirects sur le climat. Dans la couche limite (CL), ces particules ont une durée de vie relativement courte en raison de leur élimination fréquente par dépôt humide. En revanche, lorsque les aérosols sont transportés dans la troposphère libre (TL), leur durée de vie dans l'atmosphère augmente de manière significative, ce qui les rend représentatifs de vastes zones spatiales. Dans le cadre de ces travaux de thèse, nous avons utilisé une combinaison de mesures in situ effectuées à la station PUY (Puy de Dôme, 45 ° 46 'N, 2 ° 57'E, 1465 m d'altitude), ainsi que des profils LIDAR obtenus depuis Clermont-Ferrand pour identifier les conditions de TL et caractériser davantage les propriétés physiques et chimiques des aérosols dans cette zone de l'atmosphère peu documentée. Dans un premier temps, une combinaison de quatre critères a été utilisée pour déterminer le positionnement de la station PUY en TL ou en CL. Les résultats montrent que la station est située en CL avec des fréquences allant de 50% en hiver à 97% en été. Cette classification a ensuite été utilisée pour évaluer, sur un an de mesures, les différences qui existent entre la TL et la CL en termes de caractéristiques physique (distribution en taille) et chimique (fraction non réfractaire) de l’aérosol, et vis-à-vis des concentrations en carbone suie (BC). Sur la base de cette ségrégation, nous avons observé pour la plupart des saisons que les concentrations en particules des modes Aitken et accumulation ainsi que la concentration en BC sont plus élevées dans la CL que dans la TL. Cette observation est cohérente avec le fait que la majorité des sources d’aérosol sont situées dans la CL. Au contraire, des concentrations plus élevées en particules dans les modes Aitken et accumulation (notamment organiques) et en BC sont observées en TL au printemps. Ces aérosols organiques ont été identifiés comme étant âgés / moins âgés ; ils coïncident avec la présence de fortes concentrations en sulfate et en BC et sont probablement originaires de processus de combustion de biomasse, à la suite desquels ils sont directement injectés en TL sous l’effet d’une convection thermique intense. Aucune différence significative entre les concentrations de CL et de TL n'a été observée pour les particules du mode nucléation, et ce quelle que soit la saison, ce qui suggère une source supplémentaire continue de particules du mode nucléation dans la TL en hiver et en automne. Les concentrations en particules du mode grossier sont en revanche plus élevées dans la TL que dans la CL pour toutes les saisons, et en particulier en été. Cela indique un transport longue distance efficace des grosses particules dans la TL depuis des sources lointaines (marines et désertiques), probablement favorisé par les vitesses de vent accrues dans la TL par rapport à la CL. Nous avons ensuite calculé les rétro-trajectoires des masses d'air que nous avons combinées aux estimations de hauteur de couche limite du modèle ECMWF ERA-Interim pour estimer le temps passé par les masses d’air dans la TL depuis leur dernier contact avec la CL, et pour évaluer l'impact de ce paramètre sur les propriétés des aérosols. Nous avons observé que même après 75 heures sans aucun contact avec la CL, les aérosols de la TL conservent les propriétés spécifiques du type de masse d'air auquel ils appartiennent. Ce manuscrit présente également une étude des mesures simultanées au PUY et à une station urbaine à basse altitude, AtmoAura. Les résultats montrent que lorsque le PUY est en TL, les concentrations des PM1 (particules de diamètre inférieur à 1 µm) sont plus faibles au PUY qu’à AtmoAura, ce qui confirme notre classification. Lorsque le PUY est en CL, la composition en aérosol est similaire pour les deux sites, ce qui a permis de quantifier la contribution de la pollution urbaine locale issue de la ville de Clermont-Ferrand. / Aerosol particles are important due to their direct and indirect impacts on climate. Within the planetary boundary layer (BL), these particles have a relatively short lifetime due to their frequent removal process by wet deposition. When aerosols are transported into the free troposphere (FT), their atmospheric lifetime increases significantly, making them representative of large spatial areas. In this work, we use a combination of in situ measurements performed at the high altitude PUY (Puy de Dôme, 45°46’ N, 2°57’E, 1465 m asl) station, together with LIDAR profiles at Clermont-Ferrand for characterizing FT conditions, and further characterize the physical and chemical properties of aerosol in this poorly documented area of the atmosphere. First, a combination of four criteria was used to identify whether the PUY station lies within the FT or within the BL. Results show that the PUY station is located in BL with frequencies ranging from 50% during the winter, up to 97% during the summer. Then, the classification is applied to a year-long dataset of particle size distribution and NR-PM1 data’s to study the differences in particle physical and chemical characteristics and BC concentrations between the FT and the BL. Based on this segregation, we observed higher concentrations in the BL compared to FT for BC, Aitken and accumulation mode particle concentrations for most seasons, as expected from larger sources originating from the surface. However, BC, Aitken mode, accumulation mode and organic aerosols concentrations were higher in the FT compared to BL during spring. These organic aerosols were identified as aged/less aged, and were correlated with sulphate and BC and we suspect that the higher concentrations of particles observed in the FT compared to BL during spring originate from direct injection of BB aerosols in the FT through strong heat convection. No significant difference between the BL and the FT concentrations was observed for the nucleation mode particles for all seasons, suggesting a continuous additional source of nucleation mode particles in the FT during winter and autumn. Coarse mode particle concentrations were found higher in the FT than in the BL for all seasons and especially during summer. This indicates an efficient long-range transport of large particles in the FT from distant sources (marine and desert) due to higher wind speeds in the FT compared to BL. For FT air masses, we used 204-h air mass back-trajectories combined with boundary layer height estimations from ECMWF ERA-Interim to assess the time they spent in the FT since their last contact with the BL and to evaluate the impact of this parameter on the aerosol properties. We observed that even after 75 h without any contact with the BL, FT aerosols preserve specific properties of their air mass type. This manuscript is also presenting a study of simultaneous measurements at PUY and an urban low altitude station AtmoAura. Results show that when the PUY is influenced by FT air masses, the PM1 species are lower at the PUY compared to AtmoAura confirming our classification. When the PUY is predicted to lay within the BL, the aerosol composition was similar among the two sites for several species, which allowed for a quantification of the local urban pollution contribution for the species enhanced within the city of Clermont-Ferrand.
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In silico methods to prioritize chemicals with high exposure potentialReppas Chrysovitsinos, Efstathios January 2017 (has links)
Chemicals offer a wide range of desired functions and are used in a variety of consumer goods and industrial sectors. The number of individual synthetic organic chemicals produced and the total global chemical production volume are increasing. The majority of these anthropogenic chemicals are not monitored in environmental matrices nor in the indoor environment even though some are associated with undesirable consequences and the range of possible chemical impacts is still far from being fully understood. Chemicals that remain in the environment for a long time and/or distribute over a large area have high exposure potential, and will present particularly acute challenges if a currently unknown undesirable effect is discovered. This thesis describes the development of a set of in silico methods to identify and prioritize chemicals with high exposure potential that are currently not subject to national or international restrictions. In brief, we i) compiled databases of contaminants of potential concern, ii) established models to predict key properties to fill data gaps in the absence of experimental data, and iii) developed and applied methods to screen chemicals to identify those that should be assigned high priority for future study. Paper I delivers screening-level models to predict partition ratios of organic chemicals between polymeric materials commonly found indoors, and both air and water. These models can be used in high-throughput exposure assessment studies, passive sampling experiments, and models of emissions, fate and transport of chemicals. Paper II presents a scoring method to prioritize 464 organic chemicals of emerging Arctic concern for their potential to fit a set of four exposure-based hazard profiles. These four profiles represent persistent organic pollutants (POPs) regulated under the Stockholm Convention, very persistent and very bioaccumulative substances (vPvBs) regulated under REACH and for two novel and unregulated profiles derived from the planetary boundary threats framework; airborne persistent contaminants (APCs) and waterborne persistent contaminants (WPCs). APCs and WPCs are chemicals that are mobile in air and water, respectively, and that contaminate the environment in a poorly reversible manner due to their persistence. The prioritization method is based on a reference set of 148 chemicals that is used to contextualize the scoring results. Paper III describes the prioritization of 8,648 chemicals that were reportedly produced in five OECD countries. Paper III elucidates the relationship between the elemental composition of these chemicals and the exposure-based hazard scores, and presents a strategy to disentangle overlaps among the four exposure hazard profiles by categorizing chemicals according to the spatial coverage of profiles they best fit. Paper IV focuses on refining the prioritization method described in Papers II and III using a set of 5,600 hypothetical chemicals. The refined method is used to prioritize the chemicals from Papers II and III, and an additional 4,567 chemicals from the REACH database. The in silico methods developed in this thesis can be applied to conduct screening-level exposure assessments using only chemical structures as a starting point. Substances prioritized as having high potential to be POPs, vPvB, APC, or WPC should be considered for more detailed study to unequivocally determine their identity and physicochemical properties. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Manuscript.</p>
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Qualitative Analysis of Chlorinated Paraffins in Recycled PlasticsGAUDIN, Solal January 2023 (has links)
Described in many studies as dangerous for the environment and potentially carcinogenic for humans, Chlorinated Paraffins (CPs) are easily widespread due to their substantial production and use in different products. Previous studies reported the presence of CPs in different plastic polymers. However, the impact of recycled content in plastic materials on the CPs levels hasn’t particularly been considered. Recycling plastics is becoming essential but the accumulative potential of pollutants, such as CPs, need investigations. The presence of CPs in both virgin and mixed recycled and virgin plastics was studied. Plastic pellets and plastic pieces from products made of three polymer types:Poly(methyl 2-methylpropenoate) (PMMA), Thermoplastic Rubber (TPR) and Thermoplastic Polyurethane (TPU) were analysed. A solid-liquid extraction assisted by ultrasonication was performed, followed by cleanup using silica. CPs in plastic extracts were analysed by Gas Chromatography Orbitrap High Resolution Mass Spectroscopy (GC-Orbitrap-HRMS). Because of the high volatility characteristic of long chain Chlorinated Paraffins (LCCPs), only short chain and medium chain Chlorinated Paraffins (SCCPs and MCCPs ) have been studied in this project. Interesting variations in the presence of SCCPs and MCCPs have been observed from one polymer type to another. In the results, we show that MCCPs were less frequently detected compared to SCCPs. A higher detection frequency of CPs was observed for samples containing recycled plastics. The results indicate that CPs are present in plastic polymers (TPU, PMMA and TPR) and that the content of recycled material has a direct impact on the levels of SCCPs and MCCPs.
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Caractérisation de sources de pollution troposphérique en régions méditerranéenne et ouest-africaine par mesures in situ en avion et modélisation. / Characterisation of tropospheric pollution sources in the Mediterranean and West African regions by airborne in situ measurements and modellingBrocchi, Vanessa 18 December 2017 (has links)
L’étude de la pollution troposphérique inclut l’étude des gaz traces provenant de sources anthropiquesdiverses, dont l’impact varie de l’échelle locale à globale. Pour caractériser cette pollution, il est nécessairede mesurer avec précision les concentrations en polluants. Dans le cadre de projets européens, troiscampagnes aéroportées ont été conduites, dans le bassin méditerranéen, en Afrique de l’ouest et enMalaisie, pour mesurer différents types de polluants grâce, entre autres, à un spectromètre à lasersinfrarouges, SPIRIT, capable de mesurer rapidement en ligne de faibles variations de NO2 et CO. Les jeuxde données de ces gaz traces (et d’autres) ont été combinés avec un modèle lagrangien de dispersion departicules, FLEXPART, pour identifier différentes sources de pollution locales et régionales de l’air. Cettethèse présente ainsi les mesures et le travail de modélisation entrepris afin de définir les sources depollution de chaque région. Il a été montré que le bassin méditerranéen a été impacté, de la moyenne à lahaute troposphère pendant l’été, par des émissions de feux de biomasse venant de Sibérie et du continentnord-américain. Les régions ouest-africaine et malaisienne sont aussi impactées par des émissions de feuxde biomasse transportées depuis l’Afrique centrale dans le premier cas, et de feux locaux dans le second.En outre, ces régions sont influencées par des émissions provenant de l’exploitation du pétrole et du traficmaritime. FLEXPART a été utilisé afin d’identifier l’origine des pics de pollution mesurés au cours descampagnes. Nous avons ainsi montré que les conditions atmosphériques, qui définissent la hauteurd’injection du panache de la plateforme pétrolière, ainsi que le flux d’émission sont des paramètres clésdans la caractérisation des mesures par le modèle. / The study of tropospheric pollution includes the study of trace gases coming from various anthropogenicsources that can impact scales ranging from local to global. To characterise this pollution, it is necessary tobe able to measure with precision pollutant concentrations. Within the frame of European projects, threeairborne campaigns in the Mediterranean Basin, in West Africa and in Malaysia were conducted to measuredifferent types of pollutants thanks to, among others, an infrared laser spectrometer, SPIRIT, able to rapidlymeasure on-line small variations in NO2 and CO. The data sets of these trace gases (and others) have beencombined with a Lagrangian model of particle dispersion, FLEXPART, to fingerprint different sources of localand regional air pollution. Thus, this thesis presents the measurements and the modelling work undertakenin order to define the sources of pollution of each region. It has been shown that the Mediterranean Basinwas impacted, in the mid to upper troposphere during summer, by biomass burning emissions coming fromSiberia and the Northern American continent. West African and Malaysian regions are also impacted bybiomass burning emissions transported from central Africa in the first case, and from local fires in thesecond. In addition, those regions are influenced by emissions coming from oil exploitation and maritimetraffic. FLEXPART was used in order to identify the origin of the pollution peaks measured during thecampaigns. It has been shown that atmospheric conditions, which define the injection height of the oilplatform plume, and also the emission flux are key parameters in the characterisation of the measurementsby the model.
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