ABSTRACT
Water is a highly precious resource. More than half of the world's animal and plant species live in the water. Less than 5% is nonsaline (Yong, 2001), and only 0.2% and 0.3% are found in lakes and rivers, respectively, and are readily available for human use. Therefore, the protection of water and sediment quality is highly important. Rapid industrialization and urbanization leads to the contamination of sediments with heavy metals and creates a pervasive problem worldwide. Major sources of metal pollutants for the aquatic environment include agricultural and urban lands, industrial activities, spills, and accidents. In general, pollutants enter the environment through surface runoff that discharges into rivers, lakes, and groundwater or through point sources from municipalities, industries, or other sources. These contaminants pose a potential risk to the environment and human health, because they can harm aquatic organisms and enter aquatic food chains that lead to humans. Metals that enter the aquatic environment often accumulate in sediments that, subsequently, act as a source for contaminant remobilization. As, Cd, Cu, Hg, Ni, Pb, and Zn are often found in harbor sediments and in other areas that are affected by anthropogenic activities.
