Pollution assessment of the Drapetsona-Keratsini coastal seabed

Περίληψη

The pollution status of the Drapetsona-Keratsini coastal environment is assessed through sedimentological and geochemical analyses of surface sediments. The results show that the sedimentary seabed consists of sandy silts and silty sands with relatively high moisture content (up to 114%) and carbonate concentration (24- 86%), whilst the levels (measured in μg/g) of some harmful heavy metals, i.e., As=8- 2677, Cd=0.2-15.4, Cr=82-428, Cu=18-567, Fe=5700- 289,000, Hg=0.05-0.71, Mn=101-1477, Ni=25-122, Pb=18-1394, Sn=1-18, and Zn=118-4821, are particularly high. The implementation of various pollution indices, such as Geoaccumulation Index (Igeo), Potential Ecological Risk Index (RI), Pollution Load Index (PLI), Combined Contamination Index (W), and Modified Contamination Degree (mCd), together with the evaluation of biological risk using the Sediment Quality Guidelines (ERL/ERM and TEL/PEL) of NOAA indicate a very high degree of pollution with great possibility for serious and irreversible impairments for aquatic communities. The most polluted sector, probably the most heavily contaminated marine environment in Greece, is located in front of the Drapetsona rocky coast (and particularly in the Sfageion Bay), where the synergistic action of urban untreated sewage deposited in the past (before the operation of the sewage treatment plant in Psyttalia) and wastes from local industries or facilities has caused significant degradation of the marine system.