Inorganic Chemistry in the Mountain Critical Zone : Are the mountain water towers of contemporary society under threat by trace contaminants ?

Potentially harmful trace elements (PHTEs) do not accumulate homogeneously over mountainous area. Generally, highland areas receive more wet deposition, aerosols, and ions than surrounding lowlands ones, mainly due to orographic enhancement. Within mountainous areas, however, the accumulation of PHTEs is much more complex. Direct cloud deposition of contaminants could act as an important pathway of deposition either from a regional low-altitude, cloud level, orographic clouds, or haze whose frequency of occurrence is much higher than surrounding lowlands areas. The accumulation legacy of PHTEs from local human activities should also be considered when investigating PHTE distribution in mountainous areas. Combined with other phenomena, the PHTE accumulation patterns could be highly variable depending on local topography, dominant winds, and vegetation cover, as well as present and past local practices. Despite their remoteness, mountain ecosystems are highly sensitive to PHTEs loadings

Investigation of spatial and temporal metal atmospheric deposition in France through lichen and moss bioaccumulation over one century

Lichens and mosses were used as biomonitors to assess the atmospheric deposition ofmetals in forested ecosystems in various regions of France. The concentrations of 17 metals/metalloids (Al, As, Cd, Co, Cr, Cs, Cu, Fe, Mn, Ni, Pb, Sb, Sn, Sr, Ti, V, and Zn) indicated overall lowatmospheric contamination in these forested environments, but a regionalism emerged fromlocal contributions (anthropogenic activities, as well as local lithology). Taking into account the geochemical background and comparing to Italian data, the elements from both natural and anthropogenic activities, such as Cd, Pb, or Zn, did not show any obvious anomalies. However, elements mainly originating from lithogenic dust (e.g., Al, Fe, Ti) were more prevalent in sparse forests and in the Southern regions of France, whereas samples from dense forests showed an accumulation of elements from biological recycling (Mn and Zn). The combination of enrichment factors and Pb isotope ratios between current and herbarium samples indicated the historical evolution of metal atmospheric contamination: the high contribution of coal combustion beginning 150 years ago decreased at the end of the 20th century, and the influence of car traffic during the latter observed period decreased in the last few decades. In the South of France, obvious local influences were well preserved during the last century

Atmospheric Mercury Transfer to Peat Bogs Dominated by Gaseous Elemental Mercury Dry Deposition

Gaseous elemental mercury (GEM) is the dominant form of mercury in the atmosphere. Its conversion into oxidized gaseous and particulate forms is thought to drive atmospheric mercury wet deposition to terrestrial and aquatic ecosystems, where it can be subsequently transformed into toxic methylmercury. The contribution of mercury dry deposition is however largely unconstrained. Here we examine mercury mass balance and mercury stable isotope composition in a peat bog ecosystem. We find that isotope signatures of living sphagnum moss (Δ199Hg = −0.11 ± 0.09‰, Δ200Hg = 0.03 ± 0.02‰, 1σ) and recently accumulated peat (Δ199Hg = −0.22 ± 0.06‰, Δ200Hg = 0.00 ± 0.04‰, 1σ) are characteristic of GEM (Δ199Hg = −0.17 ± 0.07‰, Δ200Hg = −0.05 ± 0.02‰, 1σ), and differs from wet deposition (Δ199Hg = 0.73 ± 0.15‰, Δ200Hg = 0.21 ± 0.04‰, 1σ). Sphagnum covered during three years by transparent and opaque surfaces, which eliminate wet deposition, continue to accumulate Hg. Sphagnum Hg isotope signatures indicate accumulation to take place by GEM dry deposition, and indicate little photochemical re-emission. We estimate that atmospheric mercury deposition to the peat bog surface is dominated by GEM dry deposition (79%) rather than wet deposition (21%). Consequently, peat deposits are potential records of past atmospheric GEM concentrations and isotopic composition

Legacy Pb pollution in the contemporary environment and its potential bioavailability in three mountain catchments

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From Canals to the Coast: Dissolved Organic Matter and Trace Metal Composition in Rivers Draining Degraded Tropical Peatlands in Indonesia

International audienceWorldwide, peatlands are important sources of dissolved organic matter (DOM) and trace metals (TM) to surface waters and these fluxes may increase with peatland degradation. In Southeast Asia, tropical peatlands are being rapidly deforested and drained. The black rivers draining these peatland areas have high concentrations of DOM, and the potential to be hotspots for CO2 release. However, the fate of this fluvial carbon export is uncertain, and its role as a trace metal carrier has never been investigated. This work aims to address these gaps in our understanding of tropical peatland DOM and associated elements in the context of degraded tropical peatlands of Indonesian Borneo. We quantified dissolved organic carbon and trace metals concentrations in the dissolved and fine colloidal (<0.22µm) and coarse colloidal (0.22-2.7 µm) fractions and characterized the characteristics (δ 13 C, Absorbance, Fluorescence :excitation-emission matrix and PARAFAC analysis) of the peatland-derived DOM as it drains from peatland canals,flows along the blackwater Ambawang River, and eventually mixes with Kapuas Kecil River before meeting the ocean near the city of Pontianak in West Kalimantan, Indonesia. We observe downstream shifts in indicators of in-stream processing. The increase in the δ 13 C of DOC, along with an increase in the C1/C2 ratio of PARAFAC fluorophores, and decrease in SUVA (Specific UV Absorbance) along the continuum suggest the predominance pf photo-oxidation. However, we also observe very low dissolved oxygen concentrations, suggesting that oxygen is quickly consumed by microbial degradation of DOM in the shallow layers of water. Black rivers draining degraded peatlands show significantly higher concentrations of Al, Fe, Pb, As, Ni, and Cd. A strong association is observed between DOM, Fe, As, Cd and Zn in the dissolved and fine colloid fraction, while Al is associated to Pb and Ni and present in a higher proportion in the coarse colloidal fraction. We additionally measure the isotopic composition of lead released from degraded tropical peatlands for the first time and show that Pb originates from anthropogenic atmospheric deposition. Degraded tropical peatlands are important sources of DOM and trace metals to rivers and a secondary source of atmospherically deposited contaminants

Dissolved Organic Matter and Trace Metal Composition in Rivers Draining Degraded Tropical Peatlands in West Kalimantan, Indonesia

This dataset comprises water samples collected in the surrounding of Pontianak (0.09°N, 109.24°E) on the island of Borneo. Two sampling campaigns were conducted in June 2013 (drier period) and January 2014 (wetter period). Using a boat, samples were collected in the center of the river, from the origin of the Ambawang river (BR, black river sites) to its downstream confluence with the Landak and Kapuas KecilKecil (WR, white river sites). White river samples collected upstream of the confluence with the white river (WRu, white river upstream). Drainage canals (DC) flowing into the black river were also sampled during the second sampling campaign. In January 2014, a rain collector was installed on the roof of the Pontianak's meteorological station to collect rain samples for lead isotopic analysis

Mining legacy in French Pyrenees mountain range: new insights from environmental archives.

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Conséquences du climat holocène et des activités hydroélectriques modernes sur les écosystèmes lacustres : comparaison inter-sites (Observatoire Haut Vicdessos, France)

International audienceDans le cadre de l’Observatoire Homme Milieu Haut Vicdessos (versant Nord-Est des Pyrénées), des remplissages lacustres de la vallée de Bassiès (Lacs Majeur et Sigriou, 42°N-1°E) sont étudiés dans le but de distinguer les empreintes anthropiques et climatiques au cours de l’Holocène. Calibrée par l’échantillonnage des sols et des roches présents sur les versants, la caractérisation des constituants organiques et minéraux des sédiments lacustres prélevés dans le Lac Majeur (3 carottes sur un transect Nord-Sud) et le Lac Sigriou (carottage central) permettent de documenter l’enregistrement des périodes climatiques humides et sèches de l’Holocène supérieur. La sédimentation holocène de ces lacs apparaît très riche en matière organique. La pétrographie organique quantitative réalisée sur ces faciès démontre qu’ils sont de type dy (60% de matériel allochtone), et qu’ils résultent de l’érosion des tourbes et des sols présents en amont. En plus des descriptions visuelles et de l’imagerie X, la microfluorescence X (XRF) et les analyses élémentaires (LA ICP-MS) démontrent que ces faciès organiques sont interrompus par des passées riches en rubidium (de 96 à 148 ppm), souvent sableuses, interprétées comme liées à des phases d’activation de canyons dont le matériel est issu du dôme granitique, lui-même riche en rubidium (190 ppm). Ces canyons, présents sur chacun des systèmes lacustres, drainent les zones d’altitude soumises préférentiellement au forçage climatique. Leur activation, liée à d’intenses orages et/ou d’importantes fontes nivales, témoigne alors de périodes plus humides datées de AD1710, AD1360, AD1080, AD940, AD570, et 1690, 1830, 2640, 4210 et 4760 cal BP. Au cours du dernier millénaire, ces phases humides apparaissent synchrones entre les deux lacs, confirmant leur caractère climatique, et semblent corrélées, au moins pour cette période, aux minima solaires. Après AD1907, le niveau d’eau du Lac Majeur est régulé par la centrale hydroélectrique de Bassiès et a pour conséquence un marnage de 10 mètres affectant 37% du lac. Ceci entraîne une forte remobilisation du matériel glaciaire issu des berges, se traduisant (1) par un changement du niveau trophique du lac vers un faciès de type gyttja (75% de matériel algaire), et (2) par un doublement du taux de sédimentation durant le dernier siècle. Les faibles teneurs en rubidium enregistrées sur le faciès gyttja, jusqu’ici interprétées comme marquant des phases plus sèches, témoignent d’un marnage moins fréquent, caractéristique de périodes plus humides. Cette interprétation est validée par la présence de passées sableuses dans le Lac Sigriou lors de ces épisodes

Dating the Anthropocene in peat archives.

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CFTR -France, a national relational patient database for sharing genetic and phenotypic data associated with rare CFTR variants

International audienceMost of the 2,000 variants identified in the CFTR (cystic fibrosis transmembrane regulator) gene are rare or private. Their interpretation is hampered by the lack of available data and resources, making patient care and genetic counseling challenging. We developed a patient-based database dedicated to the annotations of rare CFTR variants in the context of their cis- and trans-allelic combinations. Based on almost 30 years of experience of CFTR testing, CFTR-France (https://cftr.iurc.montp.inserm.fr/cftr) currently compiles 16,819 variant records from 4,615 individuals with cystic fibrosis (CF) or CFTR-RD (related disorders), fetuses with ultrasound bowel anomalies, newborns awaiting clinical diagnosis, and asymptomatic compound heterozygotes. For each of the 736 different variants reported in the database, patient characteristics and genetic information (other variations in cis or in trans) have been thoroughly checked by a dedicated curator. Combining updated clinical, epidemiological, in silico, or in vitro functional data helps to the interpretation of unclassified and the reassessment of misclassified variants. This comprehensive CFTR database is now an invaluable tool for diagnostic laboratories gathering information on rare variants, especially in the context of genetic counseling, prenatal and preimplantation genetic diagnosis. CFTR-France is thus highly complementary to the international database CFTR2 focused so far on the most common CF-causing alleles