Spatial variability and ecological risk assessment of heavy metals in surface sediments of the Unete River in the department of Casanare (Colombia)

Surface sediment samples obtained from 46 sites of the Unete River in Casanare (Colombia) were analyzed to evaluate concentrations heavy metals As, Cu, Ni, Pb and Zn as well determine their geographic spatial distribution potential ecological risk. The measured compared with background values (BV), threshold effect concentration (TEC) probable (PEC) consensus-based Sediment quality criteria guidelines (SQGs) for freshwater ecosystems order level concern contaminant concentrations. Based on these results indices determined risk, As shown be metal contaminants most surface sediments. possible sources causing concerning then discussed.