Polycyclic aromatic hydrocarbons(PAHs) are one of major classes of organic pollutants that transport through air-sea exchange in the environment. The objectives of this study were to quantify the PAHs concentrations in air and seawater and calcu-late the exchange fluxes by using Whitman¡¦s two-film mode. Spatial and temporal distributions were also determined through the sampling strategy of this study. In ad-dition, particulate concentrations in the ambient air were used to estimate the dry de-position fluxes of PAHs. Seasonal fluxes of PAHs in Gao-Ping coastal areas ranged from -2020 to +320 ng/m2day. The net gas exchange fluxes were negative (net absorption) in August, No-vember and March but positive (net volatilization) in May at Kaohsiung Harbor (KH), Off Shore (OFS) and Gao-ping River Estuary (GRE). Howerer negative exchange fluxes were found in each sampling month at Liu-Chiu Isle (LCI). In contrast, Lanyu Isle (LI) showed a different tend in exchange fluxes. It¡¦s exchange fluxes were all positive in each sampling month and ranged from the +121 to +1020 ng/m2day. Mostly the net fluxes of low molecular weight PAHs were volatile; while high molecular weight PAHs were absorptive. The compound with highest flux was mostly phenanthrene, therefore, it dominates the gas exchange fluxes in Gao-Ping coastal areas. The highest average net gas exchange fluxes among stations were observed at LCI (-1650 ng/m2day) and decreased in the following order: GRE (-932 ng/m2day), KH (-824 ng/m2day), OFS (-523 ng/m2day), LI (+358 ng/m2day). Dry particle deposi-tion fluxes were higher in November and March. The high molecular weight PAHs were found predominant in these particles. Even adding up with the wet deposition, the magnitude of total deposition fluxes(dry+wet) were still lower than those of gas exchange. Therefor, gas exchange is the main transport pathway for PAHs in Gao-Ping coastal areas. By identifying composition patterns of PAHs in each sample, source of PAHs in dissolved phase were mainly from traffic emission. However, KH is indicative of in-dustrial and petrogenic souces; while grass and wood combustion and petrogenic might be the dominant source of PAHs at LI. In gas phase, sources of PAHs were mostly from combustion, including traffic emission and diesel combustion. Finally, the transport pathway of the airflow was analyzed through back trajectory analysis. The results show that the PAH concentrations in gas phase might be affected by re-gional pollution in August and May, and long-rang atmospheric transport in March at Gao-Ping coastal areas and LI. Local origin was suggested for PAHs from Gao-Ping coastal areas in November and March.

In this work, wet deposition samples were collected at Middle East Technical University campus, Ankara, between December 2000 and May 2002. Snow samples were collected from 50 grids in January, 2001 in Ankara to investigate dry deposition of PAHs. The collected samples were preconcentrated by Solid Phase Extraction and ultrasonic extraction tecniques. Extraction methodologies were improved prior to analysis of samples. Extracted samples were analyzed by Gas Chromotography-Mass Spectrometry for 14 Polycyclic Aromatic Hydrocarbons. Selected Ion Monitoring mode was used throughout the analysis. Phenanthrene, fluoranthene, pyrene and benzo (b+k) fluoranthene were found to be dominant PAHs in wet deposition samples. Seasonal variation of PAHs were observed having higher concentrations in winter period. Meterological parameters were also examined together with PAH concentrations. Contribution of PAHs coming from North East and South West direction were found to be dominant. Wet deposition fluxes were calculated and compared with other urban sites. Wet deposition fluxes are lower than industrial sites and comparable with urban sites in Europe. PAH ratios and factor analysis results demostrated combustion and traffic emissions are major sources of pollutants in the city. Dry deposition of PAHs were invesigated using snow as a natural collecting surface. Dry deposition fluxes calculated using snow surface are compareble with other similar sites. Dry deposition pollution maps of PAHs were drawn by MapInfo software and it was observed that the major pollution regions are the localities where low income families live and low quality coal used for heating purpose. Ratio calculations showed that the central parts of the city is mostly affected from traffic emissions while coal emissions are dominating at the other parts of the city. Factor analysis applied to data set and 6 factors distinquished as coal, soil, traffic, oil combustion, mixed combustion and road dust.

In this work, dry deposition of metals is investigated in an urban area / city of Ankara using snow as a surrogate surface. Two sampling campaigns were conducted to determine dry deposited amount of 13 species namely / H+, Na, K, Al, Mg, Fe, V, Cd, Cr, Cu, Pb, Zn, Ni. First sampling was performed after a major snow fall in Ankara in January 2001, from 4 points according to a predetermined sampling procedure in order to assess background composition of snow. After 12 days, snow samples were collected from 54 points. All samples are filtered, digested and divided into two aliquots in order to investigate soluble and insoluble fractions separately. Temporal changes of snow showed that snow is a good surrogate surface for dry deposition of metals and provide multifunctional informative data. Pollution maps of the city are drawn using Mapinfo software to investigate spatial pollution distributions. Factor analysis are applied and five main factors for these elements are found, indicating three main sources as traffic, soil and combustion. Enrichment factor calculations showed that Ni, Ca, Pb, Zn, Ni, Cu and Cd are highly enriched pointing out the anthropogenic sources affecting the city atmosphere drastically.

Durante o século XX ocorreram modificações importantes no meio ambiente natural em decorrência do desenvolvimento econômico da humanidade. Para estudar o impacto dessas mudanças sobre a América do Sul, um testemunho de gelo de 137 metros foi extraído da Cordilheira dos Andes, na Bacia Amazônica Ocidental, no topo do Nevado Illimani (16°37S, 67°46W, 6350 m altitude). Cerca de 80% da precipitação anual local tem origem direta em massas de ar úmidas provenientes da Bacia Amazônica. Esse testemunho de gelo foi sub-amostrado e analisado em alta resolução temporal, permitindo a interferência de variações ambientais e a caracterização de elementos traço e espécies iônicas presentes no aerossol depositado durante o século XX. Os 50 metros superiores do testemunho foram datados a partir da análise simultânea de variáveis, tais como isótopos estáveis da água, concentração total de alumínio e conteúdo iônico de Ca2+ .Essa seção de 50 metros corresponde ao registro de cerca de 80 anos entre 1919 e 1999. A acumulação de neve no testemunho mostra uma tendência de aumento, variando entre cerca de 17g H2O cm-2 ano-1 em 1919 até 65g H2O cm-2 ano-1 em 1999, Esse aumento concorda com mecanismos de acoplamento dinâmico entre oceano e atmosfera, e resultados observacionais discutidos por Bradley et al. (2003) e Cane ET AL. (1997), sendo compatível com uma redução da temperatura de superfície do mar no Oceano Pacífico Equatorial de cerca de 1,2°C ao longo do século XX, devido ao aquecimento grobal antropogênico. 744 subamostras do testemunho foram analisadas segundo as técnicas de cromatografia iônica, contagem de micropartículas insolúveis, e por espectrometria de massas (Inductively Coupled Plasma Mass Spectrometry) para a obtenção de 45 concentrações elementares entre lítio e urânio. A partir desses resultados, desenvolveu-se uma metodologia para a caracterização química do aerossol depositado em Illimani, que possibilitou a obtenção de estimativas de fluxo de deposição efetivos de elementos traço sobre os Andes ao longo do século XX. Para o cobre, elemento relacionado à exploração mineira da região do Altiplano, o pico histórico de deposição anual devido a fontes antropogênicas foi de cerca de 9,5 x 10-6 kg m-2 em 1981, enquanto o fluxo de deposição natural foi de cerca de 0,2 x 10-6 kg m-2 no mesmo ano. Considerando-se a deposição total de elementos traço em todo o século XX, nota-se que para vários metais pesados ligados a emissões antropogênicas, como níquel, cobre, zinco cádmio, entre outros, os fluxos de deposição naturais representam apenas uma fração minoritária da totalidade dos depósitos. Para esses elementos as atividades econômicas humanas constituem o principal fator responsável por sua mobilização e transporte entre reservatórios naturais no meio ambiente da Bacia Amazônica Ocidental durante o século XX. / Pendant le XX eme siécle plusieurs modifications importantes ont eu lieu dans l\'environement nature/ à cause du développement économique humain. Pour étudier l\'impact de ces modifications sur l\'Amérique du Sud, une carotte de glace 137 metreslong a été récupéré de la Cordillere des Andes, dans le Bassin Amazonien Occidental, au sommet du Nevado Illimani (16°37\'5, 67\'46\'W, 6350 m altitude). Environ 80% de la precipitation annuelle sur le site a comme origine directe des masses d\'air umides du Bassin Amazonien. Cette carotte de glace a été sous-échantilloné et analysé en haute résolution temporelle, ce qui a permis l\'inférence de variations environnementales et la caractérisation des éléments trace et especes ioniques dans l\'aérosol déposé pendant le XXème. Les premiers 50 mêtres de la carotte ont été datés a partir de l\'analyse simultanéede variables, comme les isotopes stables de l\'eau, la concentration totale del\'aluminium, et le contenu ia nique de Ca+2. Cette section de 50 metres correspond àl\'enregistrement d\'environ 80 années entre 1919 et 1999. L\'accumulation du névé dans la carotte montre une tendance d\'augmentation, entre environ 17 g H20 cm2 an1 en 1919 jusqu\'à environ 65 g H20 cm2 an\' en 1999. Cette augmentation est d\'accord avec mécanismes d\'attachement dynamique entre les océans et l\'atmosphere, et résultats d\'observations discutés par Bradley et al. (2003) et Cane et al. (1997), et compatible avec une réduction de la température de swface de la mer dans l\'Océan Pacifique Équatorial d\'environ 1,2°C pendant le XXème, dú au réchauffement global anthropogenique. 744 échantillons de la carotte ont été analysés selon les techniques de chromatographie ionique, comptage de microparticules insolubles, et par spectrométrie de masse (Inductively Coupled Plasma - Mass Spectrometry) pour obtenir 45 profils de concentration élémentaires entre le lithium et l\'uranium. A partir de ces résultats, une méthodologie a été mis au point pour la caractérisation chimique de l\'aérosol déposésur l\'Illimani, ce qui a permis l\'obtention d\'estimations de flux de déposition effectives des éléments trace sur les Andes pendant le XXème. Pour le cuivre, élément associé à l\'exploitation miniêre dans la région de /\'Altiplano, le pie historique de déposition annuel dú aux sources anthropogeniques a été d\'environ 9,5 x 106 kg m2 en 1981, tandis que le flux de déposition naturelle a été d\'environ 0,2 x 1 0\"6 kg m2 dans la même année. Si l\'on considere la déposition totale d\'éléments trace pendant le XXème, on remarque que pour plusieurs métaux lourds liés aux émissions anthropogeniques,comme le niclcel, le cuivre, le zinc, le cadmium, parmi d\'autres, les flux de déposition naturels représentent à peine une fraction minoritaire de la totalité des dépôts. Pour ces éléments, les activités économiques humaines sont le principal facteur responsable pour sa mobilisation et transport entre réservoirs naturels dans l\'environnement du Bassin Amazonien Occidental pendant le XXéme siecle.