Preliminary assessment of the trace metal concentrations in sediments of the Araçá Lagoon, Recife, Pernambuco State

Abstract

The mangroves have been suffering an intense process of environment degradation due to the amount of untreated residues discharged into effluents, principally by trace metals, thus causing contamination. The Araçá Lagoon is formed by a mangrove ecosystem, which is situated at the Recife, Pernambuco, and it is part of an the Environment Preservation Area. However, a number of anthropic activities have been contributing to its environment contamination. Therefore, this research has the objective of making a preliminary assessment of the impact on the Araçá Lagoon by such trace metals as chrome (Cr), iron (Fe), manganese (Mn) and zinc (Zn). In the sediment the manganese, zinc and chrome contents presented concentration levels above the limiting values for soils of Sao Paulo State (CETESB), and quality guides values of sediments in Canada (CCME). The iron content was compared with the limit established by the Environmental Protection Agency of the United States (USEPA) and its concentration in all stations was above the recommended limit value. The Araçá Lagoon sediments presented contamination by chrome, iron, manganese and zinc and thus presents itself as an important local accumulator of these trace metals.