Geochemical Study of Ecological Risk Potential of Heavy Metal Contamination in Urban Lake Sediment - Malaysia - from the Context of Ecological Disturbance Theoretical Tradition

This study quantified the degree of heavy metal contamination and ecological risk potential from metals concentration in urban lake sediment. The analytical method involved six geochemical indices (enrichment factor (EF), geo-accumulation index (Igeo), contamination factor (CF), degree of pollution, modified degree of contamination, & pollution load index (PLI). Sediment samples were analysed using ICP-MS. The results revealed that EF and Igeo of trace elements were in the order of Pb >Cr>Cu>Mn>Ni, whereas the order of heavy metals was Na > K > Fe > AL. Na and Pb manifested the highest level of evidence for anthropogenic enrichment and geochemical anomaly. Based on CF, the sediment is heavily contaminated by Pb, Na, and moderately by Fe, K, AL. In the event of profound ecological disturbance, and resuspension of sediment contaminants to the water column, the contamination effects of Pb, Na, Fe, K, and AL on biota will range from heavy to moderate contamination. Assessment using PLI revealed that the sediment is in 80% of locations polluted and in a progressive state of deterioration by the metals. The overall degree of metal ecological risk potentials seems higher in the northern and southern outlet parts of the lake, especially during the dry season.