Distribution of copper in the vicinity of a deactivated mining site at Carajás in the Amazon region of Brazil

In this work the re-fixation of mobilized copper (Cu) that was released from a deactivated pilot Cu ore dressing plant in the tropical rain forest at Southeastern Amazon (Carajás) was studied. Samples of top soils, decay leaf litter deposited on soils, roots and leaves of standing biomass were taken for the determination of Cu concentration in order to evaluate the distribution of it between different environmental compartments. In the sampling points near to the now extinct plant, total Cu concentrations in the soil reached an average value of 2140μgg−1 above the natural level of about 40μgg−1, being that bioavailable Cu estimated by DTPA method varied from 1. 9 to 20. 7% of this total. From the data was possible to calculate that the soil compartment is able to hold around 10kgCu/m2 of ground. Roots of the standing biomass in that area hold around 17gCu/m2, while the Cu content in leaves showed to be largely independent of the Cu level in the soil. Copper in the leaves was estimated as around 1g/m2 of ground area. In turn, the decay leaf litter deposited on soil can hold about 1. 6gCu/m2. The terrestrial system surrounding the abandoned pilot plant demonstrated great buffer capacity to retain mobile Cu released by anthropogenic activities in the area. [Copyright &y& Elsevier]