Environmental Assessment of Heavy Metal Pollution in Freshwater Sediment, Serbia

The purpose of this study was to evaluate sediment heavy metals (Cd, Cu, Co, Mn, Cr, Ni, Pb and Zn) related to pollution in freshwater sediments in Serbia. The heavy metal enrichment determination in studied sediments was conducted by using total metal content with strong acidic digestion (HCl + HNO3 + HF), a calculated enrichment factor (EF), and application of correlation analysis and the box plot method. For identification of appropriate elemental normalisers for enrichment factor calculations, Fe, Al, Ti and Si were used. The significant variation in heavy metal distribution among samples collected in this large region, encompassing all Serbian watersheds, suggests the selective contamination of sediments by heavy metals. Values for EF indicate nil to moderate enrichment for most studied elements, except for Cd, Cu, and Zn at some sampling points, where the enrichment was, in some cases, even severe. The high content of heavy metals and EFs in Serbia is related to the human activities around the sampling sites. The results indicate that all elements used for normalisation in this paper can also be used to estimate the anthropogenic influence, with an exception of Co, which should be considered as an element for normalisation in future studies.