Determination of Heavy Metals Pollution Load Index in Sediments and Aquatic Plant (Nasturtium microphyllum) in Bashar River, Yasuj

Background: Pollution of aquatic ecosystems to heavy metals is one of the most important threats of human health and its food chain. Thus, in this study the concentration of heavy metals (lead, chromium, copper, and zinc) in Surface sediments and Nasturtium microphyllum was investigated in order to assessment their effects and ecological risk. Methods: In order to assess the concentration of metals, 8 stations along the river were selected and in each station two samples of sediment and plant were taken. After preparinng and digesting the samples, the concentrations of these metals were determined using Atomic absorbtion. Results: The average of total concentration of detected metals Cr, Pb, Cu and Zn in sediment (10.33 ± 0. 02 > 13.35±1.10 > 33.07 ±6.13 > 44.02± 4.13) mg/kg respectively. In addition, evaluation indicators such as; Pollution Load Index (PLI) and ecological risk represents less pollution in the region. Also, the environmental risk of metals in the region was evaluated as (Cu> Pb> Zn> Cr). The results of concentration of metals in different organs of root, stem and leaf of Nasturtium microphyllum showed that the highest average accumulated concentration for each metal was obtained in stem, root and leaf, respectively. Conclusion: According to the results, the pollution and ecological risk of metals in the region is low evaluated. The results of this study confirm the use of Nasturtium microphyllum as a heavy metals accumulation species and a suitable indicator for their biomonitoring