Geochemistry of Metallic Trace Elements in Surficial Sediments of the Gulf of Morbihan, Brittany, France
Résumé
Concentration of selected Metallic Trace Elements (MTEs), chromium, manganese, iron, cobalt, copper, zinc, lead and cadmium in surficial sediments from gulf of Morbihan were studied in order to understand the current MTEs contamination due to urbanization and mariculture economic development surrounding the gulf region. Therefore, the distribution, enrichment and accumulation of MTEs in 101 surficial sediments collected by Orange Peel grab were characterized for MTEs content using ICP-MS after mixed acid digestion. The average concentrations of selected MTEs were 36.2±23.9 μg g-1 dry weight (Cr), 278±140 μg g-1 dry weight (Mn), 2.40±1.29% (Fe), 14.4±5.31 μg g-1 dry weight (Co), 16.4±10.3 μg g-1 dry weight (Cu), 38.1±19.1 μg g-1 dry weight (Zn), 34.6±13.9 μg g-1 dry weight (Pb) and 0.11±0.06 μg g-1 dry weight (Cd), respectively. Results from the analysis showed that MTEs studied have relatively low index of geo-accumulation and enrichment factors values and were in value to conclude practically uncontaminated within the gulf. Overall, the geochemistry of the sediment of gulf of Morbihan was influenced by both natural and anthropogenic inputs to the catchment. However, direct comparison with upper continental crust indicated that natural processes were more dominant than anthropogenic input in concentrating metals.