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Jussy, Switzerland

Bravo A.G.,University of Geneva | Cosio C.,University of Geneva | Amouroux D.,University of Pau and Pays de lAdour | Zopfi J.,University of Basel | And 4 more authors.
Water Research | Year: 2014

We examined mercury (Hg) biogeochemistry and biomagnification in the Babeni Reservoir, a system strongly affected by the release of Hg from a chlor-alkali plant. Total mercury (THg) concentrations in river water reached 88ngL-1 but decreased rapidly in the reservoir (to 9ngL-1). In contrast, monomethylmercury (MMHg) concentrations increased from the upstream part of the reservoir to the central part (0.7ngL-1), suggesting high methylation within the reservoir. Moreover, vertical water column profiles of THg and MMHg indicated that Hg methylation mainly occurred deep in the water column and at the sediment-water interface. The discharge of Hg from a chlor-alkali plant in Valcea region caused the highest MMHg concentrations ever found in non-piscivorous fish worldwide. MMHg concentrations and bioconcentration factors (BCF) of plankton and macrophytes revealed that the highest biomagnification of MMHg takes place in primary producers. © 2013 Elsevier Ltd.

Prunier P.,Institute Terre Nature Paysage | Garraud L.,Conservatoire Botanique National de Gap Charance Domaine de Charance | Kohler C.,Institute Terre Nature Paysage | Lambelet-Haueter C.,Conservatoire et Jardin botaniques de la Ville de Geneva | And 2 more authors.
Botanica Helvetica | Year: 2010

Dwarf Bulrush (Typha minima Hoppe) is an alluvial species that used to colonize most major rivers of the prealpine foothills. Since the beginning of the nineteenth century, it has been declining due to river diking as well as plugging and drainage of the floodplains. However, the magnitude of this decline is not yet precisely known. This paper quantifies the decline of Typha minima since the nineteenth century by comparing its present and past distributions. Based on information in literature and herbarium data, two distribution maps (past and present) were compiled and used to calculate the total length of colonized river banks. This resulted in a distribution of about 3,170 km of river banks during the nineteenth century but only 480 km currently (1995-2010). The overall decline thus amounted to 85%. However, there were considerable regional differences: The decline was as high as 98% in the northern and central Alps but only about 50% in France, where strategies of flood mitigation that allowed for wide river beds proved to be favourable to the conservation of Typha minima. © Springer Basel AG 2010.

Bravo A.G.,Forel Institute | Loizeau J.-L.,Forel Institute | Bouchet S.,French National Center for Scientific Research | Richard A.,Institute Terre Nature Paysage | And 3 more authors.
Environmental Science and Pollution Research | Year: 2010

Purpose: Chlor-alkali plants are one of the most important point sources of mercury to aquatic environment. The problem of Hg contamination has been studied in a region, Rm Valcea (Romania), impacted by the wastewater discharge of a chlor-alkali plant. The purpose of the present study is to evaluate the current status of mercury pollution in the Babeni reservoir (Olt River) and the exposure of local population via fish consumption to mercury originating from the chlor-alkali plant. Methods: Sediments were collected from Valcea, Govora and Babeni reservoirs. Grain size distribution, organic content and total mercury (THg) concentrations were analysed in sediments. Fish were purchased from local anglers, and the scalp hair was collected from volunteers. THg in sediment, fish and hair samples was determined using an atomic absorption spectrophotometer for Hg determination. Monomethylmercury (MMHg) was analysed in the muscle and liver tissues by species-specific isotope dilution and capillary gas chromatography hyphenated to inductively coupled plasma mass spectrometer. Results: High mercury concentrations were found in the sediments and in fish from Babeni reservoir, with a median of 2.1 mg/kg (IQR=3.2) in sediments and a mean value of 1.8±0.8 mg/kg_ww in fish muscle. MMHg concentrations in fish were well above the WHO guidelines for fish consumption. Local population consuming fish from the Babeni reservoir had THg concentrations in hair significantly higher than those consuming fish from upstream reservoirs and/or from the shops and reached a median value of 2.5 mg/kg (IQR=3.6). Conclusions: The remnant pollution in the fish of this reservoir, and probably many other lakes and reservoirs receiving Hg polluted wastewater, represents a considerable health risk for the local fish consumers. © 2010 Springer-Verlag.

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