Geochemical Assessment of Trace Metals in Kodaikanal Lake Sediments: Insights into Anthropogenic Pollution and Management Strategies

Kodaikanal Lake, a significant freshwater ecosystem and recreational site in South India, was investigated in order to evaluate sediment properties, trace metal contamination, and related risks to human health and the environment. The majority of the surface sediments were clay-rich, suggesting significant catchment weathering processes and river inflow. The order overall mean metal concentrations (mg/kg) was Fe (3345.09), Mn (72.91), Zn (59.10), Cr (37.68), Ni (26.08), Cu (13.60), Co (9.99), and Cd (2.20).With Cu (CF = 0.35; ERI = 1.75), Cr (CF = 0.63; ERI = 1.27), Co (CF = 0.88; ERI = 4.42), Ni (CF ≈ 0.90; ERI = 4.50), Zn (CF = 0.84; ERI = 0.84), Fe (CF = 0.11; ERI = 0.11), and Mn (CF = 0.15; ERI = 0.15) which suggests dominant lithogenic control. Cadmium, on the other present, demonstrated considerable anthropogenic enrichment with CF = 11.01 ± 2.01 and ERI = 330.4 ± 60.39, indicating high ecological risk. The PLI showed moderate contamination, ranging from 0.23 to 1.12. According to the non-carcinogenic risk assessment, manganese contributed the most to Hazard Index values below 1 (HQ: 0.067, children; 0.037; adults). Cadmium is the main environmental concern overall, which highlights the necessity of focused management and monitoring.