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1. Hg concentrations and stable isotope variations in tropical fish species of a gold-mining-impacted watershed in French Guiana

Author

Johanna Menges, Laurence Maurice, Régine Maury-Brachet, Laure Laffont, Patrice Gonzalez, Sylvaine Goix, Raphaelle Rinaldo, Sophie Gentès, Jeroen E. Sonke, Alexia Legeay, Université de Bordeaux (UB), UMR 5805 Environnements et Paléoenvironnements Océaniques et Continentaux (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)

Subjects
Biogeochemical cycle, Health, Toxicology and Mutagenesis, chemistry.chemical_element, 010501 environmental sciences, 01 natural sciences, Mining, chemistry.chemical_compound, Isotope fractionation, Environmental Chemistry, Animals, Humans, 14. Life underwater, Methylmercury, ComputingMilieux_MISCELLANEOUS, Ecosystem, 0105 earth and related environmental sciences, Trophic level, biology, Stable isotope ratio, Fishes, General Medicine, δ15N, Mercury, Methylmercury Compounds, biology.organism_classification, Pollution, Mercury (element), French Guiana, Mercury Isotopes, chemistry, 13. Climate action, Environmental chemistry, [SDE]Environmental Sciences, Freshwater fish, Gold, Water Pollutants, Chemical, Environmental Monitoring
Abstract

The aim of the study was to determine if gold-mining activities could impact the mercury (Hg) concentrations and isotopic signatures in freshwater fish consumed by riparian people in French Guiana. Total Hg, MeHg concentrations, and Hg stable isotopes ratios were analyzed in fish muscles from different species belonging to three feeding patterns (herbivorous, periphytophagous, and piscivorous). We compared tributaries impacted by gold-mining activities (Camopi, CR) with a pristine area upstream (Trois-Sauts, TS), along the Oyapock River. We measured δ15N and δ 13C to examine whether Hg patterns are due to differences in trophic level. Differences in δ 15N and δ 13C values between both studied sites were only observed for periphytophagous fish, due to difference of CN baselines, with enriched values at TS. Total Hg concentrations and Hg stable isotope signatures showed that Hg accumulated in fish from both areas has undergone different biogeochemical processes. Δ199Hg variation in fish (-0.5 to 0.2‰) was higher than the ecosystem baseline defined by a Δ199Hg of -0.66‰ in sediments, and suggested limited aqueous photochemical MeHg degradation. Photochemistry-corrected δ202Hg in fish was 0.7‰ higher than the baseline, consistent with biophysical and chemical isotope fractionation in the aquatic environment. While THg concentrations in periphytophagous fish were higher in the gold-mining area, disturbed by inputs of suspended particles, than in TS, the ensemble of Hg isotope shifts in fish is affected by the difference of biotic (methylation/demethylation) and abiotic (photochemistry) processes between both areas and did therefore not allow to resolve the contribution of gold-mining-related liquid Hg(0) in fish tissues. Mercury isotopes of MeHg in fish and lower trophic level organisms can be complementary to light stable isotope tracers.

Published
2021
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2. Mercury Isotope Signatures of Methylmercury in Rice Samples from the Wanshan Mercury Mining Area, China: Environmental Implications

Author

Jeroen E. Sonke, Buyun Du, Runsheng Yin, Laure Laffont, Che-Jen Lin, Ping Li, Christelle Lagane, Laurence Maurice, David Point, and Xinbin Feng

Subjects
China, 010504 meteorology & atmospheric sciences, Mercury Isotopes, chemistry.chemical_element, 010501 environmental sciences, Oryza, 01 natural sciences, Mining, chemistry.chemical_compound, Environmental Chemistry, Animals, Humans, Methylmercury, 0105 earth and related environmental sciences, Isotope analysis, Isotope, biology, food and beverages, Heavy metals, General Chemistry, Mercury, Methylmercury Compounds, biology.organism_classification, Mercury (element), chemistry, 13. Climate action, Total hg, Environmental chemistry, Environmental science, Environmental Monitoring
Abstract

Rice consumption is the primary pathway of methylmercury (MeHg) exposure for residents in mercury mining areas of Guizhou Province, China. In this study, compound-specific stable isotope analysis (CSIA) of MeHg was performed on rice samples collected in the Wanshan mercury mining area. An enrichment of 2.25‰ in total Hg (THg) δ202Hg was observed between rice and human hair, and THg Δ199Hg in hair was 0.12‰ higher than the value in rice. Rice and human hair samples in this study show distinct Hg isotope signatures compared to those of fish and human hair of fish consumers collected in China and other areas. Distinct Hg isotope signatures were observed between IHg and MeHg in rice samples (in mean±standard deviation: δ202HgIHg at −2.30‰±0.49‰, Δ199HgIHg at −0.08‰±0.04‰, n=7; δ202HgMeHg at −0.80‰±0.25‰, Δ199HgMeHg at 0.08‰±0.04‰, n=7). Using a binary mixing model, it is estimated that atmospheric Hg contributed 31%±16% of IHg and 17%±11% of THg in the rice samples and the IHg in soil caused by past mining ac...

Published
2017

3. Mercury speciation analysis in human hair by species-specific isotope-dilution using GC–ICP–MS

Author

Jeroen E. Sonke, David Amouroux, Laurence Maurice, Patricia Navarro, Laure Laffont, Philippe Behra, Mathilde Monperrus, Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Géosciences Environnement Toulouse (GET), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), Université de Pau et des Pays de l'Adour (UPPA), Laboratoire de Chimie Analytique Bio-Inorganique et Environnement (LCABIE), Université de Pau et des Pays de l'Adour (UPPA)-Centre National de la Recherche Scientifique (CNRS), Chimie Agro-Industrielle (CAI), Institut National de la Recherche Agronomique (INRA)-Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Interregional Midi-Pyrenees-Aquitaine, French National Research Agency (ANR CES) within the IDEA project, Basque Government, and [ERC-StG-20091028]

Subjects
SAMPLES, Speciation, Indicator Dilution Techniques, chemistry.chemical_element, Hydrochloric acid, MALAYSIA, METHYLMERCURY, 010501 environmental sciences, Isotope dilution, Mass spectrometry, Methylation, Sensitivity and Specificity, 01 natural sciences, Biochemistry, Gas Chromatography-Mass Spectrometry, Analytical Chemistry, Mass spectrometry/ICP-MS, Biological samples, chemistry.chemical_compound, AMAZON, ETHYLATION, Nitric acid, [SDV.IDA]Life Sciences [q-bio]/Food engineering, Humans, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, EXPOSURE, Inductively coupled plasma mass spectrometry, 0105 earth and related environmental sciences, Demethylation, Tetramethylammonium hydroxide, Organometals, Chromatography, 010401 analytical chemistry, MASS-SPECTROMETRY, Mercury, QUANTIFICATION, Methylmercury Compounds, ATOMIC FLUORESCENCE SPECTROMETRY, 0104 chemical sciences, Mercury (element), Mercury Isotopes, chemistry, Metals/heavy metals, NEUTRON-ACTIVATION ANALYSIS, Hair
Abstract

International audience; We optimized a mercury (Hg) speciation extraction method for human hair in combination with species-specific isotope-dilution analysis by gas chromatography-inductively coupled plasma-mass spectrometry (GC-ICP-MS). The method was validated on human hair reference material RM (IAEA-086), which is recommended for analysis of monomethylmercury (MMHg) and inorganic mercury (IHg). Three reagents, hydrochloric acid (HCl), nitric acid (HNO3), and tetramethylammonium hydroxide (TMAH), and three extraction procedures, at ambient temperature for 12 h, microwave-assisted at 75 A degrees C for 6 min, and oven heated at 80 A degrees C for 2 h were tested. Extraction efficiency, recovery, and potential species transformations were evaluated for each method. The most efficient procedures, with recovery of similar to 90 % for each species with limited demethylation (< 5 %) and methylation (0 %), were HNO3 digestion, irrespective of temperature, and microwave-assisted TMAH extraction. Acidic extraction with HCl induces significant demethylation, with production of artifacts. To correct for potential demethylation artifacts we recommend spiking with isotopically enriched standards before the extraction step.

Published
2012
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4. Anomalous Mercury Isotopic Compositions of Fish and Human Hair in the Bolivian Amazon

Author

Laurence Maurice, Holger Hintelmann, Philippe Behra, Marc Pouilly, Yuba Sánchez Bacarreza, Jeroen E. Sonke, Laure Laffont, Tamara Pérez, Laboratoire des Mécanismes et Transfert en Géologie (LMTG), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Department of Chemistry, Trent University, Biologie des Organismes et Ecosystèmes Aquatiques (BOREA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Instituto de Ecologia (IE), Universidad Mayor de San Andrés (UMSA), Departamento de Biología, Unidad de Limnologia y Recursos Acuáticos, UMSS, Chimie Agro-Industrielle (CAI), Institut National de la Recherche Agronomique (INRA)-Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques (ENSIACET), Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université de Toulouse (UT), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), UMSA, Laboratoire de Chimie Agro-Industrielle (LCA), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure de Chimie de Toulouse, Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques-Institut National de la Recherche Agronomique (INRA)

Subjects
Delta, Aging, Bolivia, Light, 010504 meteorology & atmospheric sciences, Drainage basin, chemistry.chemical_element, Chemical Fractionation, 010501 environmental sciences, 01 natural sciences, chemistry.chemical_compound, Age Distribution, Isotope fractionation, Population Groups, Rivers, Animals, Humans, Environmental Chemistry, 14. Life underwater, Methylmercury, Ecosystem, 0105 earth and related environmental sciences, Isotope analysis, [SDV.EE.SANT]Life Sciences [q-bio]/Ecology, environment/Health, geography, geography.geographical_feature_category, Geography, Ecology, Fishes, Aquatic animal, Mercury, General Chemistry, Methylmercury Compounds, Mercury (element), Mercury Isotopes, chemistry, 13. Climate action, Environmental chemistry, Bioaccumulation, [SDE]Environmental Sciences, Oxidation-Reduction, Environmental Monitoring, Hair
Abstract

International audience; We report mercury (Hg) mass-dependent isotope fractionation (MDF) and mass-independent isotope fractionation (MIF) in hair samples of the Bolivian Esse Ejjas native people and in several tropical fish species that constitute their daily diet MDF with delta Hg-202 ranging from -0.40 to -0.92 parts per thousand for fish and +1.04 to +1.42 parts per thousand for hair was observed. Hair samples of native people with a fish-dominated diet are enriched by +2.0 0.2 parts per thousand in 6212 Hg relative to the fish consumed. Both odd Hg isotopes, Hg-199 and Hg-201, display MIF in fish (from -0.14 to +0.38 parts per thousand for Delta Hg-201 and from -0.09 to +0.55 parts per thousand for Delta Hg-199) and in hair (from +0.12 to +0.66 parts per thousand for Delta Hg-201 and from +0.14 to +0.81 parts per thousand for Delta Hg-199). No significant difference in MIF anomalies is observed between Hg in fish and in human hair, suggesting that the anomalies act as conservative source tracers between upper trophic levels of the tropical food chain, Fish Hg MIF anomalies are 10-fold lower than those published for fish species from midlatitude lakes. Grouping all Amazonian fish species per location shows that Delta Hg-199: Delta Hg-201 regression slopes for the clear water Itenez River basin (0.95 +/- 0.08) are significantly lower than those for the white water Beni River basin (1.28 +/- 0.12). Assuming that the observed MIF originates from aquatic photoreactions, we calculated limited photodemethylation of monomethylmercury (MMHg) in the Beni River floodplains and insignificant photodemethylation in the Itenez River floodplains. This is possibly related to lower residence times of MMHg in the Itenez compared to the Beni River floodplains. Finally, a significantly negative Delta Hg-201 of -0.14 parts per thousand in Beni River fish suggests that the inorganic Hg precursor to the MMHg that bioaccumulates up the food chain defines an ecosystem specific non-zero Delta Hg-201 baseline. Calculation of photodemethylation intensities from Hg or MMHg MIF, therefore, requires a baseline correction.

Published
2009
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5. Mercury(II) trace detection by a gold nanoparticle-modified glassy carbon electrode using square-wave anodic stripping voltammetry including a chloride desorption step

Author

Teddy Hezard, Lars-Eric Heimbürger, David Evrard, Philippe Behra, Laure Laffont, Jeroen E. Sonke, Pierre Gros, Laboratoire de génie chimique [ancien site de Basso-Cambo] (LGC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Laboratoire de Chimie Agro-Industrielle (LCA), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure de Chimie de Toulouse, Géosciences Environnement Toulouse (GET), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Génie Chimique (LGC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Ecole Nationale Supérieure de Chimie de Toulouse-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), STAE (Sciences et Technologies pour l'Aeronautique et l'Espace) Foundation, European Research Council (ERC-2010-StG_20091028), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - INPT (FRANCE), Institut National de la Recherche Agronomique - INRA (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Fondation de Coopération Scientifique Science Technique Aéronautique et Espace - FCS STAE (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), Chimie Agro-Industrielle (CAI), Institut National de la Recherche Agronomique (INRA)-Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Institut National de la Recherche Agronomique (INRA)-Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques (ENSIACET), Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université de Toulouse (UT), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Institut de recherche sur l'architecture antique (IRAA), Université Lumière - Lyon 2 (UL2)-Aix Marseille Université (AMU)-Université de Pau et des Pays de l'Adour (UPPA)-Centre National de la Recherche Scientifique (CNRS), Institut méditerranéen d'océanologie (MIO), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Géochimie des Isotopes Stables (GIS), Université Fédérale Toulouse Midi-Pyrénées-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Laboratoire de Chimie Agro-Industrielle

Subjects
Stripping voltammetry, Chimie-Physique, Inorganic chemistry, Analytical chemistry, Metal Nanoparticles, 02 engineering and technology, Glassy carbon, 01 natural sciences, Chloride, Analytical Chemistry, law.invention, Chlorides, law, Desorption, medicine, Gold nanoparticles, Electrodes, Groundwater, ComputingMilieux_MISCELLANEOUS, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Detection limit, Electrolysis, Chemistry, 010401 analytical chemistry, Electrochemical Techniques, Equipment Design, Mercury, Hg(II) sensor, 021001 nanoscience & nanotechnology, Carbon, 0104 chemical sciences, Anodic stripping voltammetry, Electrode, Microscopy, Electron, Scanning, Chloride desorption step, Natural water, France, Gold, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Cyclic voltammetry, 0210 nano-technology, Water Pollutants, Chemical, medicine.drug
Abstract

International audience; Gold nanoparticles (AuNPs) were deposited on a glassy carbon (GC) substrate by constant potential electrolysis and characterized by cyclic voltammetry in H2SO4 and field emission gun scanning electron microscopy (FEG-SEM). The modified AuNPs-GC electrode was used for low Hg(II) concentration detection using a Square Wave Anodic Stripping Voltammetry (SWASV) procedure which included a chloride desorption step. The comparison of the obtained results with our previous work in which no desorption step was used showed that this latter step significantly improved the analytical performances, providing a three time higher sensitivity and a limit of detection of 80 pM for 300 s preconcentration, as well as a lower average standard deviation. The influence of chloride concentration on the AuNPs-GC electrode response to Hg(II) trace amounts was also studied and its optimal value confirmed to be in the 10-2 M range. Finally, the AuNPs-GC electrode was used for the determination of Hg(II) in a natural groundwater sample from south of France. By using a preconcentration time of 3000 s, a Hg(II) concentration of 19 +/- 3 pM was found, which compared well with the result obtained by cold vapor atomic fluorescence spectroscopy (22 +/- 2 pM).

Published
2015
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6. Hg(II) trace electrochemical detection on gold electrode: Evidence for chloride adsorption as the responsible for the broad baseline

Author

Philippe Behra, David Evrard, Laure Laffont, Pierre Gros, Teddy Hezard, Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - INPT (FRANCE), Institut National de la Recherche Agronomique - INRA (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Fondation de Coopération Scientifique Science Technique Aéronautique et Espace - FCS STAE (FRANCE), Laboratoire de génie chimique [ancien site de Basso-Cambo] (LGC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Laboratoire de Chimie Agro-Industrielle (LCA), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure de Chimie de Toulouse, Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Chimie Agro-Industrielle (CAI), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques-Institut National de la Recherche Agronomique (INRA), and STAE (Sciences et Technologies pour l’Aéronautique et l’Espace) Foundation under the ‘‘MAISOE’’ (Microlaboratoires d’Analyses In Situ pour des observatoires Environnementaux) project

Subjects
General Chemical Engineering, Inorganic chemistry, Gold electrode reactivity, Analytical chemistry, Halide, Hg(II) trace electrochemical detection, 02 engineering and technology, 01 natural sciences, Chloride, Analytical Chemistry, Adsorption, Desorption, Electrochemistry, medicine, Bovine serum albumin, Cl adsorption, Deposition (law), biology, Chemistry, 010401 analytical chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Calomel, Electrode, biology.protein, Crystallite, 0210 nano-technology, medicine.drug, Chimie théorique et/ou physique
Abstract

yadsorption a b s t r a c t Investigations were performed in order to clarify the origin of the broad baseline observed during Hg(II) trace electrochemical detection on gold electrode in the presence of Cl y anions. The influence of Cl y concentration on the shape of the voltammograms was studied in the presence and in the absence of Bovine Serum Albumin (BSA) in order to bring out adsorption/desorption processes. On the basis of these experiments, and contrary to what has been proposed by several authors in the literature, it was proved that the broad baseline does not result from calomel (Hg2Cl2) formation but is rather related to an interaction between Cl y and polycrystalline Au electrode surface. The evolution of the shape of the baseline was also studied in the presence of other halide anions, namely F y , Br y , and I y . The latter two were found to induce a broad baseline similar to that recorded in the presence of Cl y . Finally, it was shown that BSA addition is not suitable for Hg(II) detection since it prevents Hg(0) deposition onto the electrode surface.

Published
2013
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7. Hg speciation and stable isotope signatures in human hair as a tracer for dietary and occupational exposure to mercury

Author

Laure Laffont, Selma J. Luna Monrroy, Philippe Behra, Jaime Chincheros, Jeroen E. Sonke, David Amouroux, Laurence Maurice, Chimie Agro-Industrielle (CAI), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques-Institut National de la Recherche Agronomique (INRA), Géosciences Environnement Toulouse (GET), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), GET (GET), Ecole Nationale Supérieure des Télécommunications de Bretagne, Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Universidad Mayor de San Andrés (UMSA), Institut Pluridisciplinaire de Recherche sur l'Environnement et les Matériaux (IPREM), Université de Pau et des Pays de l'Adour (UPPA)-Centre National de la Recherche Scientifique (CNRS), and We would like to thank the INSU-CNRS EC2CO Program (RIMES), the IRD, the Midi-Pyrenees and Aquitaine regions, and ANR-09-JCJC-0035-01 grant for funding and cooperation agreements with Bolivian institutions. L.L. acknowledges the Ministere de l'Enseignement Superieur et de la Recherche in France for her Ph.D. grant. C. Boucayrand, M. Carayon, and C. Causserand at the GET are thanked for helping during sample preparation and experimentation, R. Freydier for assistance on the MC-ICPMS, E. Tessier for assistance on the GC-ICPMS, B. Guerrero for drawing Figure SI-SI, and D. Point and M. Monperrus for fruitful discussions. Three anonymous reviewers helped improve the quality of this contribution.

Subjects
Bolivia, 010504 meteorology & atmospheric sciences, chemical, engineering, chemistry.chemical_element, Food Contamination, 010501 environmental sciences, 01 natural sciences, Isotope fractionation, TRACER, Occupational Exposure, [SDV.IDA]Life Sciences [q-bio]/Food engineering, Environmental Chemistry, Animals, Humans, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, 0105 earth and related environmental sciences, biology, Isotope, Stable isotope ratio, Fishes, Marine fish, General Chemistry, Mercury, biology.organism_classification, Mercury (element), chemistry, water pollutants, 13. Climate action, Environmental chemistry, environmental sciences and ecology, Freshwater fish, Occupational exposure, France, Water Pollutants, Chemical, Hair
Abstract

International audience; Exposure of humans and wildlife to various inorganic and organometallic forms of mercury (Hg) may induce adverse health effects. While human populations in developed countries are mainly exposed to marine fish monomethylmercury (MMHg), this is not necessarily the case for developing countries and diverse indigenous people. Identification of Hg exposure sources from biomonitor media such as urine or hair would be useful in combating exposure. Here we report on the Hg stable isotope signatures and Hg speciation in human hair across different gold miner, indigenous and urban populations in Bolivia and France. We found evidence for both mass-dependent isotope fractionation (MDF) and mass-independent isotope fractionation (MIF) in all hair samples. Three limiting cases of dominant exposure to inorganic Hg (IHg), freshwater fish MMHg, and marine fish MMHg sources are used to define approximate Hg isotope source signatures. Knowing the source signatures, we then estimated Hg exposure sources for the Bolivian gold miner populations. Modeled IHg levels in hair correspond well to measured IHg concentrations (R = 0.9), demonstrating that IHg exposure sources to gold miners can be monitored in hair samples following either its chemical speciation or isotopic composition. Different MMHg and inorganic exposure levels among gold miners appear to correspond to living and working conditions, including proximity to small towns, and artisanal vs large scale mining activity.

Published
2011
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