Assessment of Heavy Metal (Ni, Cr) Contamination and Spatial Distribution in Surface Sediment and Soil in the Area of Lake Sawa

It is widely accepted that heavy metal contamination in sediment and soil is one of the largest threats to environmental and human health. Sediments are the principle sinks for heavy metals in aquatic environments, and can result in a secondary contamination source affecting the ecosystem. Analysis of heavy metal amounts in sediments and comparison with reference levels is a reliable indicator of ecosystem health. However, understanding the distribution of pollutants is among most essential information for environmental research and critical for environmental management and decision-making.28 samples were collected from surface (015 cm) layers of sediments in the arae of Lake Sawa. The level of pollution attributed to heavy metals was evaluated using X-Ray fluorescence analysis and comparison with reference levels of world health organization 2003 (maximum allowable concentrations in soil), Spatial distribution patterns of metals in sediments were demonstrated by employing ordinary kriging interpolation. The Results of heavy metal pollution analysis reveal a significant anthropogenic impact on the area of Lake Sawa with concentrations of several heavy metals in surface layer of sediments exceeding maximum concentrations allowable by WHO. Detected levels of chromium (Cr), nickel (Ni), demonstrate a significant pollution anomaly and high potential threat to the water ecosystem and even human health by exceeding maximum allowable concentration. A comparison of heavy metal amounts and spatial distribution patterns in the layer of sediments reveals much higher pollution levels in the surface (0-15 cm). Spatial distribution analysis demonstrates irregular distribution of most metals due to complexity of influencing physical and chemical processes, but the general trend of high concentration.