Depth-wise elemental contamination trend in sediment cores of the Sundarbans mangrove forest, Bangladesh

Abstract

In this study, depth-wise concentration variations of twenty-five elements (Na, Al, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Zn, As, Sb, Cs, La, Ce, Sm, Eu, Dy, Yb, Lu, Hf, Th and U) and their contamination levels were studied using two sediment cores from two different Ranges of the Sundarbans mangrove forest, Bangladesh. It was observed that there was a decreasing trend in concentrations of most of the studied elements from surface to the deeper layers and the rate of concentration decrement at the core from Satkhira Range was less than that of the core from Chandpai Range, indicating a more anthropogenic effect on the Chandpai range near Mongla seaport area. Different pollution indices (Igeo and EF) indicate that sediments of the Sundarbans are minor to moderately contaminated by As, Sb, Cs, REEs, Th and U. Therefore, this study suggests that proper steps should be taken to save the sensitive mangrove forest from elemental pollution.