Source Contributions to Heavy Metal Fluxes into the Loukous Estuary (Moroccan Atlantic Coast)

International audienceAluminum, iron, mercury, lead, copper, cadmium, chromium, zinc, manganese, and nickel concentrations were determined in surface and core sediment samples collected in the Loukous estuary (Atlantic Coast, Morocco) to evaluate their levels and spatial distribution. For various metals, the enrichment factor was calculated as a criterion to assess whether their concentrations represented contamination levels or could be considered background levels. Analytical results were processed using Geographical Information System software to show areas of metal accumulation. Using multivariate statistical analysis, the possibility of distinguishing the sampling stations in relation to their geographical position was evaluated. The radiolead (210Pb) and cesium 137 (137Cs) profiles in sediment core retrieved from the Loukous estuary were used to study the temporal variations in sedimentation rate and to reconstruct historical trends of heavy metal input and the effects of human activities. The results show that the distribution of metals in the Loukous estuary is principally influenced by industrial and urban wastes located mostly in the northern coastal area. Marine currents are additional factors influencing metal accumulation in sediments