Historical mass balance of cadmium decontamination trends in a major European continent-ocean transition system: Case study of the Gironde Estuary.

Despite the effective remediation efforts following the end of the metallurgic activity thirty years ago upstream the Lot River watershed, the levels of cadmium (Cd) accumulated in wild oysters from the downstream Gironde Estuary still exceed nowadays the admissible human consumption limit (5 mg/kg, d.w.).

Impact of metallurgy tailings in a major European fluvial-estuarine system: Trajectories and resilience over seven decades.

Tailings containing mining and ore treatment waste, accumulated over long time periods are major contaminant sources at the watershed scale and may seriously impair environmental quality of river-sea continuums. A critical review of existing work in different disciplines addressing the multi-metal contamination of the Gironde Watershed, a major fluvial-estuarine model system representative of many other systems worldwide, has provided a condensed, yet pertinent overview on various aspects of this environmental problem. Combining long-term observation and contamination records from different environmental archives, there is a clear trend towards resilience for the main historical contaminants (Cd, Zn, Pb and Cu), yet suggesting that resilience needs appropriate management of both, tailings as the initial source and contaminated sediments acting as temporary metal traps which may transform into delayed sources.

Rare Earth Element fluxes over 15 years into a major European Estuary (Garonne-Gironde, SW France): Hospital effluents as a source of increasing gadolinium anomalies.

New and rapidly developing technologies imply the emission of emerging potentially toxic contaminants such as Rare Earth Elements (REEs). Yet, the lithology-derived quantities and anthropogenic contributions, especially from urban areas, to annual REE fluxes into fluvial-estuarine systems remain widely unknown. The Garonne River drains water from ~20% of the French land surface hosting about 5,200,000 inhabitants and two large cities.

Organotropism and biomarker response in oyster Crassostrea gigas exposed to platinum in seawater.

Platinum (Pt) is a technology critical element (TCE) for which biogeochemical cycles are still poorly understood. This lack of knowledge includes Pt effects on marine organisms, which proved to be able to bioconcentrate this trace element. Oysters Crassostrea gigas were exposed to stable Pt isotope spiked daily in seawater for 35 days.

Platinum in sediments and mussels from the northwestern Mediterranean coast: Temporal and spatial aspects.

Platinum (Pt) is considered a Technology Critical Element (TCE) and an emerging metallic contaminant with increasing release into the environment. Gaps in knowledge and understanding of environmental levels, fate and effects of Pt still exist, especially in the marine environment. This work presents Pt concentrations in the northwestern Mediterranean coast including: (i) temporal variability from sediment cores and farmed mussels in the Toulon Bay (historically affected by intense human activities) and (ii) spatial distribution from recent wild mussels collected along ∼ 700 km coastline with contrasting ecosystems (including natural reserves), quantified using voltammetry and inductively coupled plasma-mass spectrometry.

Tracing platinum accumulation kinetics in oyster Crassostrea gigas, a sentinel species in coastal marine environments.

Platinum Group Elements (PGEs) are extremely scarce in the Earth's Crust and of strong interest for high-end technologies due to their specific properties. They belong to the Technology Critical Elements (TCEs) for which use is forecast to increase, implying growing emissions into the environment in the following years. In particular, with the intensive use of platinum (Pt) in car catalytic converters, the anthropogenic geochemical cycle of this element has surpassed the natural cycle.

Inputs, dynamics and potential impacts of silver (Ag) from urban wastewater to a highly turbid estuary (SW France).

Although silver (Ag) has been listed as a priority pollutant for the aquatic environment by the European Union (Directive 2006/11/EC), the use of Ag-based products with antimicrobial effects is increasing in Europe, as well as North America and Asia. This study investigates personal care products (PCP) as a potential source of Ag in wastewater, as well as the dynamics and fate of Ag in the influent and effluent of a major urban wastewater treatment plant (WWTP) located on the fluvial part of the Gironde Estuary. Typical household PCPs marked as using Ag contained concentrations of up to 0.

Assessment of the effects of Cu and Ag in oysters Crassostrea gigas (Thunberg, 1793) using a battery of cell and tissue level biomarkers.

Oysters are considered sentinel organisms in environmental water quality monitoring programs in which cell and tissue level biomarkers are reliable tools. Copper (Cu) and silver (Ag) are present in relatively high concentrations in several estuaries, potentially affecting environmental and human health. Crassostrea gigas oysters were exposed during 28 days to a range of environmentally relevant concentrations of Cu and Ag alone or in mixture.

Evidencing the Impact of Coastal Contaminated Sediments on Mussels Through Pb Stable Isotopes Composition.

Heavily contaminated sediments are a serious concern for ecosystem quality, especially in coastal areas, where vulnerability is high due to intense anthropogenic pressure. Surface sediments (54 stations), 50 cm interface cores (five specific stations), river particles, coal and bulk Pb plate from past French Navy activities, seawater and mussels were collected in Toulon Bay (NW Mediterranean Sea). Lead content and Pb stable isotope composition have evidenced the direct impact of sediment pollution stock on both the water column quality and the living organisms, through the specific Pb isotopic signature in these considered compartments.

Sources and historical record of tin and butyl-tin species in a Mediterranean bay (Toulon Bay, France).

Concentrations of inorganic tin (Sn(inorg)), tributyltin (TBT) and its degradation products dibutyltin (DBT) and monobutyltin (MBT) were measured in surface sediments and in two cores from the Toulon Bay, hosting the major French military harbour. Anticipating planned dredging, the aim of the present work is to map and evaluate for the first time the recent and historic contamination of these sediments by inorganic and organic Sn species derived from antifouling paints used for various naval domains including military, trade, tourism and leisure. Tin and butyl-Sn concentrations in the bay varied strongly (4 orders of magnitude), depending on the site, showing maximum values near the shipyards.

Silver behaviour along the salinity gradient of the Gironde Estuary.

Dissolved and particulate Ag concentrations (Ag(D) and Ag(P), respectively) were measured in surface water and suspended particulate matter (SPM) along the salinity gradient of the Gironde Estuary, South West France, during three cruises (2008-2009) covering contrasting hydrological conditions, i.e. two cruises during intermediate and one during high freshwater discharge (~740 and ~2,300 m(3)/s).

Comparison of periphytic biofilm and filter-feeding bivalve metal bioaccumulation (Cd and Zn) to monitor hydrosystem restoration after industrial remediation: a year of biomonitoring.

Despite a significant decrease in the metallic waste emissions from an industrial site and a remediation process initiated in 2007, the Riou-Mort watershed (southwest France) still exhibits high Cd and Zn concentrations. Metal wastes have long been proven to significantly disturb aquatic communities. In this study, bioaccumulation capacities and responses to the chemical improvement of the hydrosystem were assessed for a year along the contamination gradient through the comparison of two biological models: Corbicula fluminea and periphytic biofilms, both considered as good bioindicators.

Long-term records of cadmium and silver contamination in sediments and oysters from the Gironde fluvial-estuarine continuum - evidence of changing silver sources.

The Gironde fluvial estuarine system is impacted by historic metal pollution (e.g. Cd, Zn, Hg) and oysters (Crassostrea gigas) from the estuary mouth have shown extremely high Cd concentrations for decades.

Roles of regional hydrodynamic and trophic contamination in cadmium bioaccumulation by Pacific oysters in the Marennes-Oléron Bay (France).

The Marennes-Oléron Bay, hosting the largest oyster production in France, is influenced by the historic polymetallic pollution of the Gironde Estuary. Despite management efforts and decreasing emissions in the Gironde watershed, cadmium levels in oysters from the bay are close to the consumption limit (5 μg g(-1) dw, EC). From mid April to mid July 2009, we investigated the role of tidal resuspension and regional hydrodynamics on Cd speciation (seawater, SPM, phytoplankton, sediment, microphytobenthos) and bioaccumulation in 18 month-old oysters (gills, digestive glands, rests of tissues) reared under natural conditions (i) at ∼60 cm above the sediment and (ii) on the sediment surface.

Copper addition by organic matter degradation in the freshwater reaches of a turbid estuary.

This study reports on the relationship between copper (Cu) behavior and organic matter (OM) transformation along the turbidity gradient in the freshwater reaches of the Gironde Estuary. During a one-year survey, surface water and suspended particulate matter (SPM) were sampled at least monthly at three sites along the Garonne Branch, representing the main fluvial branch of the Gironde Estuary. Additionally, a longitudinal high resolution profile was sampled along the Garonne Branch, covering the turbidity gradient from the river water endmember to the maximum turbidity zone (MTZ).

Tracing cadmium contamination kinetics and pathways in oysters (Crassostrea gigas) by multiple stable Cd isotope spike experiments.

Laboratory experiments using stable Cd isotopes ((110)Cd and (112)Cd) were conducted to separately and simultaneously characterize Cd accumulation in different tissues of Pacific oysters (Crassostrea gigas) via the (i) trophic and (ii) direct pathways. For this, we exposed juvenile oysters to (110)Cd-spiked seawater ((110)Cd: 2 μg l(-1); constant level) and (112)Cd-spiked food (Thalassiossera weissflogii, (112)Cd: 2 μg l(-1) in 35×10(3) cells/oyster/L) in four experimental treatment groups, each containing 6 oysters, for 21 days with constant trophic feeding. These Cd contamination levels were ∼10 times lower than those typically used in experimental accumulation studies.

Long-term monitoring (1960-2008) of the river-sediment transport in the Red River Watershed (Vietnam): temporal variability and dam-reservoir impact.

The Red River (China/Vietnam, A=155,000 km(2)) is a typical humid tropics river originating from the mountainous area of Yunnan Province in China. Based on information on daily discharge (Q) and suspended particulate matter (SPM) concentration between 1960-2008 for the SonTay gauging station (outlet of the River and entry to the Delta) provided by the National Institute IMHE-MONRE, the mean annual SPM flux was estimated at 90 Mt/yr, corresponding to a sediment yield of 600 t/km(2)/yr. The temporal variability of annual SPM fluxes (ranging from 24 to 200 Mt/yr) is strongly related to the interannual hydrological conditions.

The particulate 7Be/210Pbxs and 234Th/210Pbxs activity ratios as tracers for tidal-to-seasonal particle dynamics in the Gironde estuary (France): implications for the budget of particle-associated contaminants.

The short-lived natural radionuclides (7)Be (T(1/2)=53 days), (234)Th(xs) (T(1/2)=24.1 days) and (210)Pb(xs) (T(1/2)=22.3 years), i.

Assessment of metal contamination in a small mining- and smelting-affected watershed: high resolution monitoring coupled with spatial analysis by GIS.

The Riou Mort River watershed (SW France), representative of a heavily polluted, small, heterogeneous watershed, represents a major source for the polymetallic pollution of the Lot-Garonne-Gironde fluvial-estuarine system due to former mining and ore-treatment activities. In order to assess spatial distribution of the metal/metalloid contamination in the watershed, a high resolution hydrological and geochemical monitoring were performed during one year at four permanent observation stations. Additionally, thirty-five stream sediment samples were collected at representative key sites and analyzed for metal/metalloid (Cd, Zn, Cu, Pb, As, Sb, Mo, V, Cr, Co, Ni, Th, U and Hg) concentrations.

Groundwater contributions to metal transport in a small river affected by mining and smelting waste.

The Riou Mort watershed, strongly affected by former coal mining and Zn ore treatment, has been the major source of the historical polymetallic pollution of the Lot-Garonne-Gironde fluvial-estuarine system. Two decades after the end of ore treatment, the former industrial area still contributes important amounts of metals/metalloids from various, partly unidentified, sources to the downstream river system. This study presents the high spatial variability of metal/metalloid (Cd, Zn, As, Sb, U, V) concentrations in water and suspended particulate matter (SPM) from eight observation sites during a short, intense flood event.

Potential impact of former Zn ore extraction activities on dissolved uranium distribution in the Riou-Mort watershed (France).

The industrial basin of Decazeville (Riou-Mort watershed, South-West France) is well known for its heavy metal pollution and its subsequent environmental effects on the Lot-Garonne River system. The source of this pollution is the Riou-Mort River, which drains smelting waste areas. A first survey after remediation works has revealed elevated dissolved uranium (U(D)) concentrations in the outlet of the Riou-Mort River.

Paradoxical constitutive behavioral sensitization to amphetamine in mice lacking 5-HT2A receptors.

Rationale: Although locomotor response to d-amphetamine is considered as mediated by an increased release of dopamine in the ventral striatum, blockade of either alpha1b-adrenergic or 5-HT2A receptors almost completely inhibits d-amphetamine-induced locomotor response in mice. In agreement with this finding, mice lacking alpha1b-adrenergic receptors hardly respond to d-amphetamine. However, we show here that, paradoxically, mice lacking 5-HT2A receptors (5-HT2A-R KO) exhibit a twofold higher locomotor response to d-amphetamine than wild-type (WT) littermates.

Seasonal variations and annual fluxes of arsenic in the Garonne, Dordogne and Isle Rivers, France.

Daily measurements of water discharges and suspended particulate matter (SPM) concentrations and monthly analyses for arsenic were conducted from 1999 to 2005 on the Garonne, Dordogne and Isle Rivers, the three main tributaries of the Gironde Estuary, France. Despite the known historical polymetallic pollution affecting the Lot-Garonne River system, the highest As concentration level was observed in the Isle River. This was explained by the geological context and various Au/As deposits in this watershed.

Irreversible blockade of monoamine oxidases reveals the critical role of 5-HT transmission in locomotor response induced by nicotine in mice.

Although nicotine is generally considered as the main compound responsible for addictive properties of tobacco, some experimental data indicate that nicotine does not exhibit all the characteristics of other substances of misuse such as psychostimulants and opiates. For example, nicotine generally fails to induce locomotor response in mice and self-administration of nicotine is difficult to obtain in rats. We have shown recently that a pretreatment with mixed irreversible monoamine oxidase inhibitors (MAOIs), such as tranylcypromine, triggers a locomotor response to nicotine in mice and induces a robust self-administration of nicotine in rats.

Geochemical signals and source contributions to heavy metal (Cd, Zn, Pb, Cu) fluxes into the Gironde Estuary via its major tributaries.

Daily measurements of water discharges and suspended particulate matter (SPM) concentrations and monthly sampling for trace element analyses (Cd, Zn, Pb and Cu) were conducted from 1999 to 2002 on the Garonne, Dordogne and Isle Rivers, the three main tributaries of the Gironde Estuary, France. Dissolved and particulate Cd, Zn, Pb and Cu concentrations in the Isle River were generally higher than those in the Garonne River, despite the known historical polymetallic pollution affecting the Lot-Garonne River system. Even if the relatively high dissolved metal concentrations in the Isle River may be of importance for the local ecosystem, metal inputs into the estuarine and coastal zones are mainly controlled by fluvial transport via the Garonne River.