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Horvat, Milena
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Horvat, Milena
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- PublicationRestrictedMercury Degassing on Africa-Adriatic Tectonic Plate Margin(American Geophysical Union, 2009-12)
; ; ; ; ;kotnik, Joze; Department of Environmental Sc., Jozef Stefan Institute, Ljubljana, Slovenia ;Giammanco, Salvatore; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Horvat, Milena; Department of Environmental Sc., Jozef Stefan Institute, Ljubljana, Slovenia ;Fajon, Vesna; Department of Environmental Sc., Jozef Stefan Institute, Ljubljana, Slovenia; ; ; Beside anthropogenic influences, mercury in the environment can also be of natural origin. Among geologic sources, volcanic activity has been of main interest so far. Modern estimations of global natural emissions are between 2000 and 5200 tonnes per year. However, these estimates are very uncertain, thus more detailed and systematic research on natural sources of mercury is necessary. Tectonic activity is connected to certain phenomena such as degassing of Hg and other gases from active faults, geothermal activity, volcanoes, etc., especially on tectonic plate margins. Elemental mercury concentrations in air, soil gases and fluxes, as well as its speciation, in connection to tectonic activity, were studied in different environments such are karst cave (Postojna Cave), active volcano areas (Mt. Etna, Italy), and active tectonic areas in the Mediterranean Basin on Africa-Adriatic tectonic plate margin. Postojna Cave is characterized by elevated Hg (up to 150 ng m-3) air concentrations at certain areas in vicinity of active faults; however the concentrations showed also strong seasonal variations. Mt. Etna on Sicily is the largest and most active Mediterranean volcano. Concentrations of mercury in air in the vicinity of the volcano are relatively high (between 4 and 30 ng m-3) and rise towards the summit crater (65 to 130 ng m-3). Concentrations in sulphatare and fumaroles gases on the summit of the volcano can reach very high values (even up to 60 μg m-3). The Mediterranean Basin is characterized by strong tectonic activity as a consequence of subduction of African plate under the Eurasian plate. A possible source of DGM (dissolved gaseous mercury in sea water) in deeper and bottom waters could be intensive tectonic activity of the seafloor, since higher concentrations and portions of DGM were found near the bottom at locations with strong tectonic activity (Alboran Sea, Strait of Sicily, Tyrrhenian Sea, Ionian Sea). Distribution of different mercury species in sediment and water of the Mediterranean Sea showed that the main source of mercury is geotectonic activity and its accompanying phenomena.118 17 - PublicationRestrictedA compilation of field surveys on gaseous elemental mercury (GEM) from contrasting environmental settings in Europe, South America, South Africa and China: separating fads from facts(2013-12-31)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;Higueras, P.; Departamento de Ingenierı´a Geolo´gica y Minera, Escuela Universitaria Polite´cnica de Almade´n, Universidad de Castilla-La Mancha, Plaza M. Meca 1, 13400 Almade´n, Spain ;Oyarzun, R.; Instituto de Geologı´a Aplicada (IGeA), Universidad de Castilla-La Mancha, Plaza M. Meca 1, 13400 Almade´n, Spain ;Kotnik, J.; Department of Environmental Sciences, Jozef Stefan Institute, Ljubljana, Slovenia ;Esbrı´, J. M.; Instituto de Geologı´a Aplicada (IGeA), Universidad de Castilla-La Mancha, Plaza M. Meca 1, 13400 Almade´n, Spain ;Martìnez-Coronado, A.; Instituto de Geologı´a Aplicada (IGeA), Universidad de Castilla-La Mancha, Plaza M. Meca 1, 13400 Almade´n, Spain ;Horvat, M.; Department of Environmental Sciences, Jozef Stefan Institute, Ljubljana, Slovenia ;Lòpez-Berdonces, M. A.; Instituto de Geologı´a Aplicada (IGeA), Universidad de Castilla-La Mancha, Plaza M. Meca 1, 13400 Almade´n, Spain ;Llanos, W.; Exploraciones Mineras S.A. (EM), Avenida Apoquindo 4775, Providencia, Santiago, Chile ;Vaselli, O.; Dipartimento di Scienze della Terra, Unversita´ di Florence, Via G. Pira, 4, 50121 Florence, Italy ;Nisi, B.; CNR-IGG Istituto di Geoscienze e Georisorse, Via Moruzzi 1, 56124 Pisa, Italy ;Mashyanov, N.; Department of Geology, St. Petersburg State University, 7/9 Universitetskaya nab., St., Petersburg 199034, Russian Federation ;Ryzov, V.; Department of Geology, St. Petersburg State University, 7/9 Universitetskaya nab., St., Petersburg 199034, Russian Federation ;Spiric, Z.; OIKON, Institute for Applied Ecology, Avenija Dubrovnik 6-8, 10 020 Zagreb, Croatia ;Panichev, N.; Department of Chemistry, Tshwane University of Technology, P.O. Box 56208, Arcadia, Pretoria 0007, South Africa ;McCrindle, R.; Department of Chemistry, Tshwane University of Technology, P.O. Box 56208, Arcadia, Pretoria 0007, South Africa ;Feng, X.; State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China ;Fu, X.; State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China ;Lillo, J.; Escuela Superior de Ciencias Experimentales y Tecnologý´a, Universidad Rey Juan Carlos, Tulipa´n s/n, 28933 Mo´stoles, Madrid, Spain ;Loredo, J.; Departamento de Explotacio´n y Prospeccio´n de Minas, E.T.S. Ingenieros de Minas, Universidad de Oviedo, C/ Independencia 13, 33004 Oviedo, Spain ;Garcìa, M. E.; Facultad de Ciencias Quý´micas, Universidad Mayor de San Andre´s, Campus de Cota-Cota, La Paz, Bolivia ;Alfonso, P.; Departament d’Enginyeria Minera i Recursos Minerals, Universitat Polite`cnica de Catalunya, Catalunya, Spain ;Villegas, K.; Departament d’Enginyeria Minera i Recursos Minerals, Universitat Polite`cnica de Catalunya, Catalunya, Spain ;Palacios, S.; Departament d’Enginyeria Minera i Recursos Minerals, Universitat Polite`cnica de Catalunya, Catalunya, Spain ;Oyarzu´n, J.; Departamento de Ingenierý´a de Minas, Universidad de la Serena, La Serena, Chile ;Maturana, H.; Departamento de Ingenierı´a de Minas, Universidad de la Serena, La Serena, Chile ;Contreras, F.; Facultad de Agronomı´a (Maracay), Universidad Central de Venezuela, Maracay, Venezuela ;Adams, M.; Facultad de Agronomı´a (Maracay), Universidad Central de Venezuela, Maracay, Venezuela ;Ribeiro-Guevara, S.; Centro Atomico, Bariloche, Argentina ;Niecenski, L. P.; Universidade Federal do Rio Grande, Porto Alegre, Brazil ;Giammanco, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Huremovic´, J.; Prirodno matematicki fakultet, Sarajevo, Bosna and Herzegovina; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; Mercury is transported globally in the atmosphere mostly in gaseous elemental form (GEM, Hg0 gas), but still few worldwide studies taking into account different and contrasted environmental settings are available in a single publication. This work presents and discusses data from Argentina, Bolivia, Bosnia and Herzegovina, Brazil, Chile, China, Croatia, Finland, Italy, Russia, South Africa, Spain, Slovenia and Venezuela. We classified the information in four groups: (1) mining districts where this contaminant poses or has posed a risk for human populations and/or ecosystems; (2) cities, where the concentration ofatmospheric mercury could be higher than normal due to the burning of fossil fuels and industrial activities; (3) areas with natural emissions from volcanoes; and (4) pristine areas where no anthropogenic influence was apparent. All the surveys were performed using portable LUMEX RA-915 series atomic absorption spectrometers. The results for cities fall within a low GEM concentration range that rarely exceeds 30 ng m-3, that is, 6.6 times lower than the restrictive ATSDR threshold (200 ng m-3) for chronic exposure to this pollutant. We also observed this behavior in the former mercury mining districts, where few data were above 200 ng m-3.We noted that high concentrations of GEM are localized phenomena that fade away in short distances. However, this does not imply that they do not pose a risk for those working in close proximity to the source. This is the case of the artisanal gold miners that heat the Au–Hg amalgam to vaporize mercury. In this respect, while GEM can be truly regarded as a hazard, because of possible physical–chemical transformations into other species, it is only under these localized conditions, implying exposure to high GEM concentrations, which it becomes a direct risk for humans.378 77