Comprehensive Assessment of Heavy Metal Pollution and Ecological Risk in Lakes of Bangalore, Karnataka, India

Abstract

The contamination of water and sediment by heavy metals poses significant challenges to freshwater ecosystems, agriculture, and aquaculture. This study focused on assessing heavy metal pollution in Ulsoor and Agara Lakes, prominent freshwater reservoirs in Bengaluru utilized for aquaculture. The presence of heavy metals such as Cd, Cu, Zn, Cr and Pb levels were analyzed in water and sediment samples of both lakes over a period of one year (from August 2021 to July 2022), using an Atomic Absorption Spectrometer. Pollution indices (CF, Igeo, PLI, ERI) were computed for sediment, revealing higher metal concentrations compared to water. Correlation analysis identified strong associations between Zn and Cu, Pb and Zn in water, and Cu and Cd in sediment, suggesting common pollution sources. While sediment showed relative safety based on PLI, Igeo, and ERI, CF indicated an unpolluted to moderately polluted status. In conclusion, this study revealed that most metals in the water exceeded permissible limits, highlighting the need for effective remediation measures.