Anthropogenic metal pollution in Saronikos gulf: historical evolution and risk assessment based on selected sediment cores

Anthropogenic metals (Cd, Cu, Hg, Pb, Zn) are chemical elements known for toxic effects when present in elevated concentrations. There are various sources of these metals to marine sediments. The presence and levels of anthropogenic metals in sediments may cause adverse implications to ecosystem and human health. The present paper is a preliminary presentation of anthropogenic metal levels in selected short sediment cores obtained during a 2017 sampling campaign in the various sub-areas of Saronikos (Elefis bay, Eastern, Western and Outer). The vertical distribution of Cd, Cu, Hg, Pb and Zn along with sediment quality evaluation are discussed. In the background sediment layers (below 15-20cm) the ranges of Cu, Pb, Zn, Hg and Cd (in mg/kg) are 9.3-37.3, 18.8-35.1, 16.8-85.3, 0.019-0.033 and 0.041-0.090 respectively. In upper sediment layers affected by anthropogenic pollution the ranges of Cu, Pb, Zn, Hg and Cd (in mg/kg) are 13.7-138, 33.9-181, 35-435, 0.031-1.73 and 0.051-0.65. The metal contents in the sediments of Saronikos generally do not exceed the ERL (effects range low) and ERM (effects range median) sediment quality guidelines widely used as risk indicators to benthic biota. However, most metals in Elefsis bay and Hg in Elefsis and other locations of Saronikos as well, present elevated concentrations above the quality limits posing risk to marine biota and possibly to human health.