EDXRF Detection of Trace Elements in Salt Marsh Sediment of Bangladesh and Probabilistic Ecological Risk Assessment

The surface salt marsh sediments from marine ecosystems in the Bay of Bengal, Bangladesh was assessed for trace elements like iron (Fe), calcium (Ca), titanium (Ti), potassium (K), strontium (Sr), rubidium (Rb), zirconium (Zr), zinc (Zn), copper (Cu) and lead (Pb), their potential sources, and associated ecological risks. The range of trace elements in sediment (mg/kg) followed the decreasing order: Fe (25020-35176) > Ca (8679-16323) >Ti (2678-3340) > K (23680-16770) > Sr (138.32-209.64) > Rb (124-186.57) > Zr (96.21-161.35) > Zn (37.71-44.95) > Cu (36.51-51.66) > Pb (1.35-10.42). The concentrations of trace elements were under the average shale values of metals in sediment except for Fe, Cu and Rb, which can occasionally be associated with adverse biological effects. Contamination level and ecological risk were evaluated using contamination factor (CF), enrichment factor (EF), geo-accumulation index (I-geo), pollution load index (PLI), and potential ecological risk index (PERI). Multivariate statistical technique was used to classify the metal sources. The results showed that Fe was significantly enriched in the sediments. Ecological risk factors illustrated a pollution-free condition of the salt marsh ecosystem in Bangladesh.