Anna Barros

Metals in the sediments of Jauá Lake (Camaçari, Bahia, Brazil) following an episode of industrial contamination

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 Jaua Lake, along the coast of Camacari, 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 Jaua 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 sed...

Rehabilitation Following Industrial Contamination: Jauá Lake, a Coastal Wetland in Camaçari, Bahia, Brazil

In North America and Europe, there is a broad consensus among scientists, the public, and politicians on the importance of wetlands. As a direct consequence wetlands are well studied and laws provide some protection for these ecosystems. However, in the tropical zone of South America, wetlands are seen as unusable lands and nuisance sites that support disease vectors. Therefore, neotropical wetlands have been subjected to severe pressures since the early years of colonization by Europeans. Although wetlands are a conspicuous part of the landscape in South America and floodplains alone cover many hundreds of thousands of square kilometers (Sippel et al. 1992, Junk 1993), little is known about these systems. Only one wetland study (Junk and da Silva 1995) is presented in Tundisi et al.’ s (1995) recent review of limnology in Brazil, South America’ s largest country. More optimistic though is the fact that during the XXVI Congress of the International Association of Theoretical and Applied Limnology, held in Sao Paulo (SIL 1995), thirty-two presentations out of 830 dealt with the question of neotropical wetlands.