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Metals in the sediments of Jauá Lake (Camaçari,
Bahia, Brazil) following an episode of industrial contamination
EM. daSilvaa,
M.F.T. Navarrob, A.F. Barrosb,
M.F.V. Motab, C.B.A. Chastinetc
aInstituto
de Biologia da Universidade Federal da Bahia, Campus de Ondina,
40210-170 Salvador, Bahia, Brazil
bBiomonitoramento e Meio Ambiente LTDA. Rua Guedes Cabral,
184 Sala 05, 41950-620 Salvador, Bahia, Brazil
cInstituto do Ambiente e Vida, Universidade de Coimbra, 3000
Coimbra, Portugal
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Abstract
The contamination of sediments caused by the deposition
of industrial residues from titanium dioxide production, in sand
dunes near a wetland was assessed through atomic absorption spectrometry.
The contamination occurred near a shallow freshwater wetland called
Jauá Lake, along the coast of Camaçari, Bahia, Brazil.
Five core samples were collected, including a reference site, from
Jaua Lake and one from a small lake, near the deposition site. Cores
were cut in 20-cm sections. Fractions <63 µm were analysed
for copper, cadmium, zinc, iron, lead, aluminium, mercury and titanium.
Metal concentrations on the upper layer of sediments were, as a
whole, higher than in lower ones. Concentrations from the reference
site were similar to those from the other sites in Jauá Lake.
Absolute values of most metals in the sediments of the Dunas Lake
located near the contamination site were higher than in all other
stations. The hypothesis, that:: (1) contamination coming from groundwater
would contaminate the sediment; and (2) there would be a gradient
of decreasing contamination from sites near the residue deposit
to sites located further away, were rejected. The continuous removal
of groundwater may have contributed to the reduction of further
contamination. It is recommended that future studies examine the
concentration of metals in plants and the role of plants in metal
bioavailability. © 2000 Elsevier Science Ltd and AEHMS. All
rights reserved.
Keywords:Wetlands; Core sampling
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