An ecological risk investigation of marine sediment from the northern Mediterranean coasts (Aegean Sea) using multiple methods of pollution determination

The aim of this study is an assessment of metal pollution levels in Aegean Sea sediment. Sediment samples collected from 7 different locations (Yenikoy, Edremit, Ayvalik, Dikili, Aliaga, Hekimadasi, and Ildir) along the northern Mediterranean region of Turkey were investigated for 11 elements (Cu, Fe, Zn, V, Cd, Ni, As, Pb, Mn, Co, and Cr). Graphite furnace atomic absorption spectrophotometry (GFAAS) and flame atomic absorption spectrophotometry (FAAS) were used for elemental analysis. The findings were evaluated with sediment assessment methods by taking two different values as a reference and then investigating the adverse biological effects of elemental profiles on living organisms. Pb, Mn, As, Cd, and Cr concentrations were within a moderate to significant range in terms of contamination factor (C-f(i)), albeit varying according to reference and location. Themost problematic region and elements regarding the enrichment factor (EF) wasAyvalik and As, Ni, Cu, Pb, Co, and Cd. However, according to the EF, the anthropogenic effect was not at an alarming level. This was further supported by the results of the geoaccumulation index (Igeo). The findings of themodified degree of contamination (mC(d)) and the pollution load index (PLI) suggested that the accumulation was greatest in Ayvalik, and the least in Hekimadasi and Ildir. The location with the highest elemental total toxic unit (Sigma TU) was Edremit. The effect of the existing element profile on organisms was 21% in this location when the mean effect range-median quotient (m-ERM-q) was considered. As and Ni concentrations in all stations were found to be higher than threshold effect level (TEL) and Effect Range Low (ERL). Ni levels in Edremit exceeded the probable effect level (PEL) and Effect Range Median (ERM). Toxic unit (TU) values of these two elements in all stations ranged from 59.30 to 80.43%.