Komposisi Geokimia Sedimen Pantai di Pulau Langkawi, Kedah, Malaysia

A total of 40 surface sediment samples collected from Pulau Langkawi namely Pulau Daya Bunting, Pulau Tuba and Selat Kuah were analyzed to determine the heavy metal content such as Co, Pb, Ni, Cr, Zn and Cu. Sediment parameters such as pH, organic matter content and particle size distribution usually considered influential in heavy metal enrichment were also determined. The abundance of heavy metals Co, Pb, Ni, Cr, Zn and Cu in sediment samples ranged at 13-75 μgg-1, 9-113 μgg-1, 3-57 μgg-1, 2-26 μgg-1, 8-69 μgg-1 and 2-14 μgg-1, respectively. The values of pH and organic matter content ranged at 3.95-8.39 and 0.06-15.01%, respectively, whilst the particle size distribution was dominated by sand with values of more 70%. Correlation analysis showed that the organic matter content and the presence of silt and clay minerals controlled the abundance of heavy metal in the sediment, whereas heavy metal content had a significant positive correlation at above 1% level with all elements. The Co and Pb heavy metal concentrations were above the critical level where potential toxicity in soil and sediment may occur. This could be attributed to input of effluent from development activity in the inland or from the sea.