An investigation into the heavy metal burden of Akkulam–Veli Lake in south India

The heavy metal burden of Akkulam–Veli Lake, a shallow lake in southern part of India, is investigated through the analysis of surface sediments. The average concentrations of heavy metals such as lead, chromium, nickel, copper, zinc, cobalt, iron, and manganese were determined at selected stations. The degree of contamination of selected stations was evaluated using indices such as enrichment factor, contamination factor, and pollution load index and compared with sediment quality guidelines. Statistical analysis is carried out by correlation analysis and hierarchical clustering analysis to identify relatively homogeneous groups of cases. The results of this study indicate severe contamination at most of the stations selected. The degree of contamination of the lake could be rated as ‘moderate’ to ‘strong’. The average pollution load index shows progressive deterioration of sediment quality indicating ‘risk’ on the aquatic environment and ecosystems of the lake.