|Abstract Title:||Historical Evolution of Hg in Sediments of Saronikos Gulf, Greece|
|Presenter Name:||Georgia Panagopoulou|
|Company/Institution:||Laboratory of Environmental Chemistry, Department of Chemistry, National and Kapodistrian University of Athens|
|Session:||Mercury in Contaminated Sites|
|Co-Authors:||Georgia Panagopoulou,Vasiliki Paraskevopoulou,Eirini Anagnostou,Eirini Vrettou,Konstantinos Lazogiannis,Fotini Botsou,Manos Dassenakis,Michael Scoullos|
Abstract Information :
Saronikos Gulf is the marine area adjacent to the city of Athens. To the north on the coastline of the relatively enclosed Elefsis bay various types of industries began operation in the early 1900?s and industrial activity peaked from 1960 to 1990. Currently the industrial activities include shipyards, oil refineries, cement production plants and various smaller industries. Apart from the industrial zone other activities also add to the Hg load. The population of urban centres (Athens, Piraeus, suburbs) is estimated to be around 5 million. There are two wastewater treatment plants, Psitalia and Thriasio, discharging effluents in Saronikos and Elefsis bay respectively.Furthermore, there is increased atmospheric pollution due to vehicle traffic and household heating and finally increased ship traffic since Piraeus is the largest Greek port. As part of on-going monitoring representative surface sediments samples and sediment cores from Saronikos were collected and analysed for Hg content. The samples were frozen after collection and freeze-dried. The total Hg content was extracted via digestion with concentrated nitric acid in closed Teflon beakers. Hg concentrations were measured by Cold Vapour Atomic Adsorption Spectrometry. Grain size distribution between silt-clay and sand sediment fractions was also evaluated. The sediment Hg levels decrease from the more polluted Elefsis bay and Inner Saronikos to the Outer gulf. In the surface sediments Hg ranged from 26 to 1453?g/kg while background pre-industrial levels ranged from 19 to 40?g/kg. In the two most affected stations Hg exceeded both the ERL and ERM quality guidelines and in a few other stations the ERL limit therefore toxic effects to biota are plausible. The Hg pollution status of Saronikos Gulf is not alarming but due to the multitude of polluting activities and in line with the implementation of EU Water Framework Directive and Marine Strategy Framework Directive monitoring efforts are continuing.