Arundo donax as a potential biomonitor of trace element contamination in water and sediment

Environmental monitoring through living organisms is an effective technique of human impact assessment, based on reliable and cost-effective biological tools of control. In this study, roots, stems and leaves of the worldwide distributed macrophyte Arundo donax (giant reed) were tested as potential biomonitors of trace element contamination in water and sediment. In particular, the concentrations of the following elements were analyzed: Al, As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, Zn. A two-year sampling was conducted in an urban watercourse of Catania (Sicily, Italy), affected by municipal and industrial discharges of wastewaters. Results showed that the amount of concentrations in plant tissues is significantly dependent on the kind of organ and element. Trace element concentrations decreased according to the pattern of root>leaf>stem, implying that roots acted as the main centers of bioaccumulation, and stems as transit organs as a consequence of the general high translocation from roots to leaves. Overall, A. donax showed a significant capacity of bioaccumulation in agreement with ecologically similar macrophytes. Positive correlations were found between trace concentrations in plant organs and sediment (Al, Cr, Mn, Ni, Zn), and water (Cu, Ni, Zn). The results of this study suggested that A. donax acts as an ecological indicator of environmental conditions, thus, its application may prove a useful tool during monitoring campaigns of wetlands.