Kajian geokimia logam berat dan penilaian kualiti sedimen marin dan tanah sekitar Teluk Marudu, Sabah Malaysia

The study area is located around Kudat which are Sg. Karang and Kg Tampakan for marine sediment sampling and several other localities around the district for the soil sampling. The main objectives in this study is to investigate the geochemistry of 9 selected heavy metals (V, Cr, Mn, Co, Ni, Cu, Zn, As and Pb) as well as the sediment quality on the area. A total of 8 soil samples and 120 marine sediment samples from 8 localities and 20 sediment core stations were chosen in this research. The sediment quality assessment involves a number of methods and indexes including Sediment Quality Guidelines, Geoaccumulation Index, Enrichment Factor, Contamination Factor and Pollution Load Index. The analysis on SK shows pH average of 5.80 - 6.30, organic matter percentage 1.80% - 9.66% and soil texture classification of loamy sand, sandy loam and sandy clay loam. Meanwhile heavy metals V, Cr, Mn, Co, Ni, Cu, Zn, As and Pb have average values of 2.73 ppm, 3.35 ppm, 11.76 ppm, 0.37 ppm, 2.22 ppm, 2.76 ppm and 3.77 ppm repectively. Mineralogy analysis shows the presence of montmorilonite in the samples from this area. For samples at Pantai Kg. Tampakan, the average pH values are 8.00 - 8.36, organic matter percentage 2.00% - 2.37% and sand, loamy sand as well as sandy loam soil texture. The metals V, Cr, Mn, Co, Ni, Cu, Zn, As and Pb shows average concentration of 3.05 ppm, 8.64 ppm, 68.83 ppm, 0.55 ppm, 5.56 ppm, 2.03 ppm, 5.69 ppm, 0.71 ppm and 4.46 ppm respectively. Other than that, mineralogy analysis indicated the presence of magnetite and chromite. Geochemical analysis and quality assessment towards the control samples or the soil samples shows different stages of metal Mn, Pb, Ni and As pollution in ophiolite and melange samples due to lithogenic and anthropogenic sources. Comparison between geochemical characteristic, mineralogy and heavy metal distribution of SK and KT proves that the samples were influenced by the nearby parent rock. The sediment quality assessment also shows that lithogenic source does not cause any heavy metal pollution on the study area. However, continuous monitoring must be conducted to avoid long term pollution towards the ecosystem in Teluk Marudu, Sabah