Influence of Watershed Land Use on Contamination of the Sediments of Lake Victoria, Africa: A Case Study of Pesticides, Alkylphenols, and Antimicrobial Agents.

Freshwater lakes are vulnerable to land-use changes that promote the input and accumulation of organic pollutants in sediments, posing risks to aquatic ecosystems. This study assessed the relationship between watershed land use and the occurrence of selected pesticides, antimicrobial agents, and alkylphenols in surface sediments of Lake Victoria in Africa. Surface sediment samples (n = 38) were collected in September 2019 across the Uganda, Kenya, and Tanzania sides of the lake. The samples were extracted using ultrasound-assisted extraction (UAE) and analyzed by gas chromatography-mass spectrometry (GC-MS). 16 out of 23 target compounds were detected, with pesticides showing low concentrations (1 (4-tert-octylphenol, 2-phenylphenol, 4-phenylphenol, β-HCH, and 4-n-octylphenol) that pose potential aquatic ecotoxic risks to aquatic organisms. This study demonstrates that activities related to agriculture, industrialization, and urban development are the main drivers of sediment contamination in the lake, highlighting the need for targeted catchment management and monitoring.