Assessment of element concentrations in surface sediment samples from Sigacik Bay (eastern Aegean)

Concentrations of Al, Fe, As, Co, Cr, Cu, Mn, Ni, Pb, Zn, Hg, and organic carbon, and grain size distribution were investigated in the surface sediments of 7 sampling stations in the Sigacik Bay (western Anatolia) in December 2016. At all of the sampling stations, the concentrations of Pb, Ni, Cr, and As were higher than the average shale values. The highest concentrations of Pb, Cu, Zn, As, and Hg were found at stations near Doganbey Cape. The possible sources of pollution were evaluated using several parameters: the enrichment factor (Et), contamination factor (Cf), and contamination degree (Cd). The Ef values ranged between 0.12 and 7.61 in the bay. The high Ef (>1.5) values of Pb, Cu, Ni, Co, and As were assessed to explain the influence of anthropogenic sources. Additionally, the Cf values ranged from 0.46 to 5.61, while the Cd values ranged from 11.69 to 20.45 in the study area. The Cd of the Cr and As ranged between moderate and considerable, and the highest Cd was measured at stations near Doganbey Cape. Additionally, the pollution degrees were assessed using sediment quality guidelines (SQGs), the threshold effect level (TEL), the probable effect level (PEL), the effects range low (ERL), and the effects range median (ERM). It was demonstrated that the sediments were generally heavily polluted with Cr and Ni, and moderately with Pb and Cu, according to the numerical SQGs. The concentrations of Pb, Cr, Cu, Zn, and Ni were above the TEL, while Cr and Ni were also higher than the PEL levels for all of the samples.