J. Phys. IV France 107 (2003) 281
Solid and aqueous mercury in remote river sediments (Litany River, French Guyana, South America)L. Charlet, G. Roman-Ross, L. Spadini and G. Rumbach
Environmental Geochemistry Group, LGIT-OSUG, BP. 53, 38041 Grenoble cedex 9, France
Mercury content in river sediments was investigated, in the Haut Maroni river basin (French Guyana, South America), around Antecume-Pata, a village where Wayanas Amerindians are contaminated with mercury. Solid sediment particulate total mercury content indicate a 100 to 150 ng/g Hg geochemical background level. Sediments act as an environmental archive: gold mining contaminated sediments have up to 400 ng/g total mercury. Pore waters from contaminated sediments are enriched in Fe(II) and Hg(II) by a factor 40 compared to uncontaminated sediment pore waters, due to more acute anoxie conditions. They act therefore as a major source of dissolved mercury in remote tropical aquatic ecosystems. Keywords: Mercury, sediment, DGT and DET techniques, pore water, gold mining.
© EDP Sciences 2003