Assessment of metal concentration in the sediment cores of Manakudy estuary, south west coast of India

Base line data on the metal concentration was obtained from three core sediments (S1, S2 and S3) of Manakudy estuary on the south west coast of India. The acid leachable trace metals (Cr, Cu, Ni, Co, Pb, Zn and Cd) showed peak values at sulphidic phase. There is moderate level of pollution related to anthropogenic activities. The trace metals were associated with Fe and Mn indicating their adsorption onto Fe-Mn oxyhydroxides. The correlation of trace metals with sulphur indicates that they were precipitated as metal sulphides. Correlation matrix showed elegant association between trace metals and Fe, Mn, S and mud. The Igeo values revealed that all the core samples fell within uncontaminated to moderately contaminated category. The concentration factor was low (C-f(i) <1) indicating low contamination in the core samples. The anthropogenic factor (AF) values indicate moderate anthropogenic inputs.