title: Sources and fate of mercury pollution in Almadén mining district (Spain): Evidences from mercury isotopic compositions in sediments and lichens.
abstract: Variations in mercury (Hg) isotopic compositions have been scarcely investigated until now in the Almadén mining district (Spain), which is one of the most impacted Hg areas worldwide. In this work, we explore and compare Hg isotopic signatures in sediments and lichens from Almadén mining district and its surroundings in order to identify and trace Hg aquatic and atmospheric contamination sources. No statistically significant mass independent fractionation was observed in sediments, while negative Δ(201)Hg values from -0.12 to -0.21‰ (2SD = 0.06‰) were found in lichens. A large range of δ(202)Hg values were reported in sediments, from -1.86 ± 0.21‰ in La Serena Reservoir sites far away from the pollution sources to δ(202)Hg values close to zero in sediments directly influenced by Almadén mining district, whereas lichens presented δ(202)Hg values from -1.95 to -0.40‰ (2SD = 0.15‰). A dilution or mixing trend in Hg isotope signatures versus the distance to the mine was found in sediments along the Valdeazogues River-La Serena Reservoir system and in lichens. This suggests that Hg isotope fingerprints in these samples are providing a direct assessment of Hg inputs and exposure from the mining district, and potential information on diffuse atmospheric contamination and/or geochemical alteration processes in less contaminated sites over the entire hydrosystem. This study confirms the applicability of Hg isotope signatures in lichens and sediments as an effective and complementary tool for tracing aquatic and atmospheric Hg contamination sources and a better constraint of the spatial and temporal fate of Hg released by recent or ancient mining activities.
authors.affiliation: Laboratoire de Chimie Analytique, Bio-Inorganique et Environnement, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux (IPREM), CNRS-UPPA-UMR-5254, Hélioparc, 2 Avenue du Président Pierre Angot, Pau F-64053, France; Department of Analytical Chemistry and Food Technology, Faculty of Environmental Sciences and Biochemistry, University of Castilla-La Mancha, Avenida Carlos III s/n, Toledo E-45071, Spain. Electronic address: maria.jimenez@uclm.es.
authors.forename: María
authors.initials: M
authors.lastname: Jiménez-Moreno
authors.affiliation: Laboratoire de Chimie Analytique, Bio-Inorganique et Environnement, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux (IPREM), CNRS-UPPA-UMR-5254, Hélioparc, 2 Avenue du Président Pierre Angot, Pau F-64053, France.
authors.forename: Julien P G
authors.initials: JP
authors.lastname: Barre
authors.affiliation: Laboratoire de Chimie Analytique, Bio-Inorganique et Environnement, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux (IPREM), CNRS-UPPA-UMR-5254, Hélioparc, 2 Avenue du Président Pierre Angot, Pau F-64053, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Perrot
authors.affiliation: Laboratoire de Chimie Analytique, Bio-Inorganique et Environnement, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux (IPREM), CNRS-UPPA-UMR-5254, Hélioparc, 2 Avenue du Président Pierre Angot, Pau F-64053, France.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Bérail
authors.affiliation: Department of Analytical Chemistry and Food Technology, Faculty of Environmental Sciences and Biochemistry, University of Castilla-La Mancha, Avenida Carlos III s/n, Toledo E-45071, Spain.
authors.forename: Rosa C
authors.initials: RC
authors.lastname: Rodríguez Martín-Doimeadios
authors.affiliation: Laboratoire de Chimie Analytique, Bio-Inorganique et Environnement, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux (IPREM), CNRS-UPPA-UMR-5254, Hélioparc, 2 Avenue du Président Pierre Angot, Pau F-64053, France. Electronic address: david.amouroux@univ-pau.fr.
authors.forename: David
authors.initials: D
authors.lastname: Amouroux
mesh_terms: D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000032:analysis*; D019015:Geologic Sediments / Q000032:analysis*; D008011:Lichens / Q000737:chemistry*; D008629:Mercury Isotopes / Q000032:analysis*; D008906:Mining; D045483:Rivers / Q000737:chemistry; D013030:Spain
chemical_list: D004785:Environmental Pollutants; D008629:Mercury Isotopes
keywords: Almadén mining district; Isotopic tracing; Lichens; Mercury; Sediments