Abstract
Trace metals in natural water such as iron, copper and zinc are essential micronutrients for aquatic organisms. However, they pose toxin when they are present in excess. It is known that the bioavailability and toxicity of metals depend on the concentration of inorganic metals, not the total metal concentration. Therefore it is important for the conservation of aquatic organisms to understand the chemical form of metals (i.e. chemical speciation). In this study, we analyzed and compared trace metal speciation in urban rivers affected by human activities such as wastewater and natural rivers with small influence on the Sagami River basin. As a result, it was suggested that the concentration of dissolved organic matter is relatively small in the natural river, and therefore the inorganic metal concentration increases due to lower degree of complexation, resulting in the higher bioavailability of metals.
