Distribution and provenance of heavy metals in sediments of the Vrbas River, Bosnia and Herzegovina

Heavy metals are naturally occurring elements, but they are regarded as significant environmental pollutants due to high density and high toxicity even at low concentrations. The aim of this paper is evaluation of the pollution level of heavy metals in the river and riverbank sediments as well as the estimation of their origin and spatial differences along the course of the Vrbas River through Banja Luka. The concentrations of metals have been assessed using the Inductively coupled plasma - optical emission spectrometry and Advanced mercury analyzer for mercury determination. Anthropogenic impact on heavy metal concentration in sediments was estimated by calculating pollution indices: Geoaccumulation index (Igeo), Contamination factor (Cf), Pollution Load Index (PLI), and Potential Ecological Risk Index (Er). Obtained results indicate that there is no statistically significant spatial difference in metal concentration, indicating that heavy metals in sediments have a constant source. The anthropogenic impact expressed by values of pollution indices showed that sites are generally uncontaminated by Co, Cr, and V and moderately contaminated by Zn, Cu, and Ni. On the contrary, lead, mercury and cadmium pose the highest ecological risk. The anthropogenic source of Pb, Hg and Cd is industry, municipal waste and the combustion of fossil fuels. Obtained results demonstrate the high ecological risk and need for environmental monitoring, supporting an efficient strategy to reduce local pollution and contamination of the investigated system.