The aim of the present 1-year study was to investigate the effect of heavy metals in synthetic fertilizers on water and sediment quality in the Seyfe Lake, where agricultural activity was the only anthropogenic source. Metal concentrations of five different types of synthetic fertilizers used in agricultural fields within the Seyfe Lake closed basin were as follows: Zn > Pb > Cu > Cr > Cd > As > Ni > Co. The annual average of heavy metal concentrations in the sediment samples were as follows: Zn > Pb > As > Cr > Ni > Cu > Cd > Co. Seyfe Lake sediment was classified as anthropogenically "highly polluted" in terms of the As and Zn concentrations at each sample station based on the sediment quality guidelines. Furthermore, the sediment could be classified as "moderately to highly polluted" in terms of the As concentration, based on the geo-accumulation index.
Keywords: Enrichment factor; Fertilizers; Geo-accumulation index; Heavy metals; Sediment quality guidelines.