Copper, zinc, and chromium accumulation in aquatic macrophytes from a highly polluted river of Argentina

SERAFINI, ROBERTO JOSÉ MARÍA; ARREGHINI, SILVANA; TROIANI, HORACIO ESTEBAN; DE IORIO, ALICIA ROSA FABRIZIO

ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH

SPRINGER HEIDELBERG

Año: 2023

0944-1344

The aims of this study were to assess Cu, Zn, and Cr pollution in a highly polluted river in Argentina (Matanza-Riachuelo)and to evaluate tolerance strategies and toxic effects in aquatic macrophytes. Chemical techniques were used to assess thebioavailability of these metals and to evaluate their uptake and translocation by plants. The ultrastructure of the roots of afree-floating plant (Eichhornia crassipes) and the leaves of an emergent macrophyte (Sagittaria montevidensis) was examinedusing transmission electron microscopy. In the lower basin of the river, the highest concentrations of total heavy metalswere detected in water (179 μgZn/g; 54 μgCu/g; 240 μgCr/g) and sediments (1499 μgZn/g; 393 μgCu/g; 4886 μgCr/g).In the upper basin of the river, low percentages of Zn and Cu (8 to 25%) were extracted with DTPA and EDTA, probablydue to the lithogenic origin of these metals. Higher extraction percentages (24 to 66%) were obtained in the lower basin, inaccordance with anthropogenic pollution. For Cr, extraction percentages were low in the upper basin of the river (< 4.5%)and extremely low in the lower basin (< 0.03%). In S. montevidensis, the BCF (bioconcentration factor) and TF (translocationfactor) indexes were compatible with heavy metal exclusion mechanisms in sediments, whereas in the E. crassipes, rootcompartmentalization could be the main tolerance strategy. The leaves of S. montevidensis showed no evidence of damage,whereas ultrastructural alterations (plasmolyzed cells, disorganized membranes) were observed in E. crassipes.