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Anodontites trapesialis; Castalia ambigua; BIVALVIA; Pantanal; mercury; biomonitoring; biosays
Abstract:
The present work is a study and research about gold mining as a main
destruction activity in the district of Poconé northem border of the
Pantanal in the state of Mato-Grosso. The inadequate way of using
mercury during the process of treatment to obtain gold is worring. The
study of the fauna and flora of Poconé is a way of contributing to the
process of evaluation of this activity of the Pantganal. In the present
work, two species of Molluscs Bivalves were selected, Castalia ambigua
and Anodontites trapesialis in order to determine the total amount of
mercury used during the process of mining, and its use in bioassays in
the laboratory. This result was obtained in a Spectrophotometer of
Atomic Fluorescence with a grade of sensibility measure in
subnanogrames. Determinations made with the Castalia ambigua at the
Corrego Piranema (0.64 ± 0.70 µgHg.g-1) and the Bento Gomes River (0.37
± 0.0.35 µgHg.g-1) of which the waters drain the mining areas, showed
concentrations of mercury in a total amount above that permitted by the
WHO (1991). The organisms that function as filters can be used more
efficiently to indicate the presence of mercury in the process of
analysis, it was clear that the series which compound the floating
organisms are important factor in the process incorporation of the
mercury. Organisms which were submitted to a process of treatment where
just Hg0 was used, presented decreasing values in a amount of 1.32 to
1.86 µgHg.g-1. This result shows that the transportation and the process
of incorporation of bioincreasing of this metal are directly related to
the material formed by the suspension material transported by the water
of the rivers.