Naslov
Mercury speciation and distribution in a North France Wetland

Autori
Niessen, Sylvie ; Mikac, Nevenka ; Wartel, Michel

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
ESF Conference "Chemical Speciation and Bioavailability" / - Castelvecchio Pascoli, 1999

Skup
ESF Conference "Chemical Speciation and Bioavailability"

Mjesto i datum
Lucca, Italija, 10.10.1999. - 15.10.1999

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Sažetak
It was recently shown that internal production of methyl mercury (MeHg) is not the only source of MeHg in freshwater ecosystems. External sources include the atmospheric deposition and runoff the from terrestrial catchments. The relative importance of these sources varies in different situations. Terrestrial catchments containing wetlands were found to be important sites for MeHg production and a principal source of MeHg for downstream ecosystems. Consequently, fish from the lakes that receive significant inflow from wetlands often have high concentrations of MeHg. In this work distribution of mercury species was studied in one wetland area located in the Scarpe-Escaut Natural Reserve in the northern France. Investigated lakes were formed during coal mine activities, which strated in 1870 and finished in 1970. The aim of the study was to evaluate the level of the total Hg and MeHg in this wetland and the bioavailability of mercury in the aquatic food chain. Mercury speciation was performed in different compartments (water, sediment, porewater, aquatic plants and fish) in samples collected in the period January-June 1999. The total Hg was analysed by CV AAS after acid digestion of solid samples. MeHg was analysed by aqueous phase ethylation-headspace GC. The total Hg in water ranged from 0.5 to 4.2 ng/L and it was mostly complexed with organic matter (usually less than 20% of reactive Hg). The total Hg in sediments varied between 180 and 400 ng/g containing up to 0.7 % of MeHg. Aquatic plants and fish also show a low level of the total Hg. This preliminary study suggests that, despite an intensive mining in the area, the investigated ecosystem is not highly contaminated with mercury. More data on the MeHg distribution in aquatic organisms is necessary to asses the bioavailability of mercury species in the aquatic food chain.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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