Native plants from Brazilian coast: bioaccumulation for the bioremediation of radioactive contamination

Abstract

Worldwide, there is a current tendency of pacific uses of the Nuclear Energy for energetic purposes. In Brazil, the expansion of the Brazilian Nuclear Program will involve the installation of 50 new power plants. As the presence of radioactive contaminants is associated to the uranium production and consumption, it is evident the necessity for monitoring and remediation of further environmental impacts. One of the most important contaminants is the cesium-137, however the evaluation of diverse radionuclides such as uranium-238 and thorium-232 may help to define the most appropriated organisms for using as biomonitors/bioremediators. Considering the knowledge about the radionuclide accumulation is still incipient in the Brazilian Coast Region, the project Bio2 Bioaccumulation for Bioremediation aims at the use of aquatic native plants as phytoremediation by phytoextraction of radionuclides by analyzing the substrate, as well as the biologic compartments of native plants occurring in the Cananéia-Iguape System. The expected results are the relevance of studies underlying vegetation from marine ecosystems and/or under strong marine influence; the radionuclide fallout through atmosphere and suspended sediments, followed by the estimative of radionuclide reservoir in the vegetation; the first evaluation of radionuclide cycling in mangroves; the standardization of sampling for bioaccumulation studies, the success of modeling of transfer factors associated to the prediction of further impacts and the indication of bioaccumulator native species for remediation by phytoextraction. The Project Bio^2, besides stimulating the collaboration among specialists and capacitating human resources, will bring a new approach for the researches carried out in the BIOTA Program relative to the utilization of information from biodiversity for the definition of reference standards for studies of radioactive contamination. Moreover, this project will promote a noticeable sample bank to be available to other researchers, following the premise of multidisciplinary of environmental researches. (AU)